JPH06106819A - Electronic device - Google Patents

Abstract

PURPOSE:To cut the number of component for an electronic device to simplify a configuration. CONSTITUTION:An operating switch 135 which is electrically shut off and is allowed to communicate as an appropriate action to open and close a top housing 23, is provided. This operating switch 135 supplies and shuts off a power supply voltage to a motor 126 and a high voltage unit, and supplies an output even to a comparator 138. The comparator 138 detects a decrease in the output level of the operating switch 135, further checks the open state of the top housing 23 and connects a signal to an engine controller 131.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device, for example, an electronic device such as an LED (light emitting diode) printer using electrophotography.

[0002]

2. Description of the Related Art FIG. 71 is a system diagram showing an electrical configuration of a typical conventional LED printer 1. Commercial power such as commercial AC 100V is supplied to the LED printer 1 via a power cable 2, and the housing 3 of the LED printer 1 is provided with a power switch 4 that can be operated from the outside. The drive power supplied through the power switch 4 is converted into a drive voltage of a predetermined level and output through the power circuit 5.

Here, in the LED printer 1, a photosensitive drum 1 is provided by a motor 6 for transporting a recording paper on which electrophotographic printing is performed in the machine body and an LED array 7.
Before the formation of an optical image by the transfer discharger 9 for transferring the toner image obtained by developing the electrostatic latent image formed on the recording medium 0 by the developing device 8 to the recording paper or the LED array 7, From the power supply circuit 5 to the high voltage portion 12 requiring a relatively high voltage such as the charging / discharging device 11 for uniformly distributing the predetermined potential on the photosensitive drum 10, for example, +
A drive voltage such as 24V is supplied.

In such an apparatus using the electrophotographic technique, the lower housing 13 constituting the housing 3 is opened with a cover 14 which is openably and closably mounted.
It is stipulated by law that when the inside of the LED printer 1 is exposed, the rotation of the motor 6 and the supply of the high voltage to the high voltage section 12 should be stopped. Therefore, the power supply circuit 5 and the motor 6 are interlocked with the opening / closing operation of the cover 14.
And a switch 15 for disconnecting / conducting between the high voltage part 12 and
Is provided. On the other hand, when the cover 14 is opened, the printing operation of the LED printer 1 needs to be interrupted, and the print interrupted state needs to be transmitted to a host computer such as a word processor that supplies print data to the LED printer 1. There is.

In order to perform such processing, the CPU (central processing unit) 16 provided in the LED printer 1 needs to detect the open / closed state of the cover 14. Therefore, the cover detection switch 17 is provided. For example, the cover detection switch 17 is made conductive when the cover 14 is closed and cut off when the cover 14 is opened. At this time, the CPU 16 reads whether the output of the cover detection switch 17 is at the low level or the low level, and the above-described processing is performed.

[0006]

In the LED printer 1 of the conventional example as described above, the number of switches provided in association with the opening / closing operation of the cover 14 is two, so that the number of parts is increased and the wiring thereof is increased. Also has a problem that the configuration becomes complicated.

An object of the present invention is to solve the above technical problems and to provide an electronic device having a simplified structure.

[0008]

DISCLOSURE OF THE INVENTION The present invention is provided in association with a cover body in an electronic device including a box-shaped housing having an opening at one end and a cover body for opening / closing the opening of the housing. Switch means for interrupting / outputting power source power in accordance with the open / closed state of the cover body,
In an electronic device having a drive mechanism connected to the switch means for applying / cutting off power source power, the cutoff / output state of the power source connected to the switch means is detected to detect the open / closed state of the cover body. The electronic device is provided with a detection unit.

[0009]

The electronic device according to the present invention comprises a housing and a cover body for opening / closing the opening portion of the housing. Switch means is provided in relation to the cover body to cut off / output the power source power in accordance with the open / closed state of the cover body, and the power source power from the switch means is supplied to the drive mechanism. On the other hand, a detection means is connected to the switch means, and the open state of the cover body is detected by detecting the cutoff state of the power source power in the switch means.

[0010]

【Example】

(1) Mechanical Configuration of LED Printer FIG. 1 is a block diagram showing the electrical configuration of an LED (light emitting diode) printer 21 which is an embodiment of the present invention, and FIG. 2 is a system diagram showing the configuration of the LED printer 21. 3 is a cross-sectional view excluding the drive mechanism of the LED printer 21. The LED printer 21 has an upper opening and a substantially box-shaped lower housing 22 and a lower housing 22.
And an upper housing 23 in the shape of a lid. The upper housing 23 is angularly displaceable via a support shaft 24 in the vicinity of an end portion on the downstream side in the transport direction A1 of the recording paper inside the machine body of the LED printer 21, and near the upper end portion of the lower housing 22 near the end portion. Be combined with. The lower housing 22 opens upward. The lower housing 22 is surrounded by a lower cover 221 made of synthetic resin, and the upper housing 23 is covered by an upper cover 222 made of synthetic resin.
A shaft 6 is attached to the lower cover 221 near the downstream end of the upper housing 23 and the lower housing 22 in the transport direction A1.
A rear cover 60 that is pin-coupled at 1 is arranged.

The recording paper 2 is placed in the lower housing 22.
The paper feed cassette 29 in which 5 are stacked and stored is detachably mounted from the upstream side in the transport direction A1. In this paper feed cassette 29, a substantially semi-cylindrical paper feed roller 30 is provided on the take-out side of the stored recording paper 25, that is, the right side of FIGS. A lifting plate 31 is provided that is biased upward by spring force. The paper feed roller 30 has a semi-cylindrical shape as described above, and supplies and stops the recording paper 25 for each cycle of rotation.

The carrying direction A of the lower housing 22
The paper feed roller 30 is rotatably mounted on the upstream side of the LED printer 21 so as to have a rotation axis that is parallel to the width direction of the LED printer 21 orthogonal to the carrying direction A1, that is, the direction perpendicular to the paper surface of FIG. A sensor 33 for detecting the presence or absence of the recording paper 25 in the paper feed cassette 29 is arranged on the downstream side of the paper feed roller 30 in the transport direction A1 and above the lifting plate 31. The sensor 33 includes a detection lever that is angularly displaceable around an axis parallel to the width direction, and an optical sensor that optically detects the detection lever. That is, when there is no recording paper 25 on the lifting plate 31, the detection lever is angularly displaced downward, and when the optical sensor detects the detection lever in this state, the recording paper 25 is stored in the paper feed cassette 29. A missing condition is detected.

The recording paper 25, of which the paper feed roller 30 has started to feed toward the upstream side in the carrying direction A1 near the upstream end in the carrying direction of the LED printer 21, is the feeding direction in the carrying direction A1 downstream side. Inversion path 3 to invert toward
After passing through 6, the pair of conveying rollers 37 clamps the sheet and further conveys the sheet, and the sheet is sandwiched by the registration rollers 38. A sensor 39 for detecting the recording paper is arranged near the upstream side of the registration roller 38 in the transport direction A1. The sensor 39 also includes a detection lever 40 and an optical sensor 41 that optically detects the end portion of the detection lever 40 when the detection lever 40 is angularly displaced depending on the presence or absence of recording paper.

The recording paper 25 that has passed through the registration rollers 38.
The transfer device 42 performs a transfer process as described later. The transfer device 42 has a box-like shape that is long in the width direction of the LED printer 21, and has a shield case 4 made of a metal material having an opening at one end in a direction orthogonal to the width direction.
3 and a transfer discharger 100 including a discharge wire 44 stretched around the shield case 43.

The recording sheet transferred by the transfer device 42 is conveyed to the fixing device 46. Fixing device 46
In a substantially box-shaped housing 47, a pressure roller 48 and a heating roller 49 are arranged in contact with each other, and the pressure roller 48 elastically contacts the heating roller 49 by a spring (not shown). Around the heating roller 49, the thermistor 1 for measuring the temperature of the cleaning piece 52 and the heating roller 49.
47 is abutted and arranged. A sensor 5 for detecting the recording paper 25 is provided on the downstream side of the fixing device 46 in the transport direction A1.
1 is provided. The sensor 51 includes the above-mentioned sensors 33,
The detection lever 53, which has the same configuration as that of the recording paper 25, projects to the conveyance path of the recording paper 25, and the recording paper 2 of the detection lever 53.
And an optical sensor 54 for detecting an angular displacement due to the pressing by 5. A rear unit 55 that includes the detection means 51 and constitutes the downstream end of the lower housing 22 in the transport direction A1 is provided.

The rear unit 55 includes the sensor 5
With respect to No. 1, in order to eject the recording paper after fixing on the downstream side in the transport direction A1 to the outside of the machine, the paper ejection roller 5 is placed at a position facing each other.
8, 59 are provided respectively. The rear unit 55
An opening 101 is formed on the downstream side in the transport direction A1 with respect to the paper discharge rollers 58 and 59, and a rear cover 60 that covers the opening position in an openable and closable manner is provided below the opening 101 of the rear unit 55. It is mounted via 61 via angular displacement.

On the inner side of the rear cover 60, the discharge rollers 58 and 59 are connected in the vicinity of their contact positions, and the discharge rollers 5
A reversing member 62 having a substantially semi-circular inner peripheral surface for reversing the moving direction of the recording paper from 8, 59 toward the upper side and the upstream side of the conveying direction A1 and constituting the reversing path 102.
Is provided. Near the end position of the reversing member 62, paper discharge rollers 64 and 65 are provided at positions facing each other in order to discharge the conveyed recording paper to the stacker 223 formed on the upper cover 222.

The carrying direction A of the upper housing 23
1, a holding member 66 that opens toward the upstream side in the transport direction A1 is angularly displaceably mounted in the vicinity of a substantially central position along which the process cartridge 73 is detachably mounted.

The following description is an outline of the process cartridge 73, and the details will be described later. The process cartridge 73 includes a toner box 7 in which toner is stored.
The housing 75 has a housing 75 for detachably accommodating 4. The housing 75 includes a developing roller 76 and a photosensitive drum 77.
And are rotatably attached to each other at predetermined intervals with parallel axes. The process cartridge 73 is provided with an agitator 78 that mixes the toner stored in the toner box 74 with a carrier and supplies the toner to the developing roller 76 as a developer. A toner sensor 104 for detecting the toner concentration in the developer is provided near the agitator 78.

Inside the housing 75, around the photosensitive drum 77, downstream of the developing roller 76 in the rotational direction A2 of the photosensitive drum 77, that is, on the lower side of FIG.
Cleaning blade 79 for scraping off the toner remaining on the photosensitive drum 77 after the transfer processing by the transfer device 42.
A cleaning device 80 including the above and a charger 81 such as a corona discharger for uniformly charging the surface of the photosensitive drum 77 with electric charges of a predetermined polarity are arranged. A gap is provided between the charger 81 and the developing roller 76, which is swingably mounted on the upper housing 23.
An LED head 82 that generates light for forming a desired optical image on the surface of the photosensitive drum 77 that is charged by 1 is arranged in the gap.

In the vicinity of the upstream end of the lower housing 22 in the conveying direction A1, the recording paper 25 from the paper feed cassette 29 is reversed in the conveying direction toward the downstream side in the conveying direction A1 as shown in FIG. LED printer 2 near the top
Manual feeder 8 for manually feeding paper in 1
3 is provided. The manual sheet feeding device 83 includes a loading table 84 on which a recording sheet for manual feeding is placed. Board 84
A transport roller 86 for feeding the recording paper into the body of the LED printer 21 is provided on the top. Below the loading table 84, the loading table 84 is provided to switch between feeding the recording paper for transfer in the LED printer 21 from the paper feeding cassette 29 or the manual feeding device 83. A sensor 87 is provided to detect the presence or absence of the upper recording sheet. This sensor 87 corresponds to each of the sensors 33,
A detection lever 88 having the same configuration as that of 39 and the like, which can be angularly displaced by being pressed by the loading of the recording paper on the loading platform 84.
And an optical sensor 89 for detecting the angular displacement operation of the detection lever 88.

The recording paper conveyed from the manual paper feeder 83 to the downstream side in the conveying direction A1 by the conveying roller 86 is nipped by the conveying roller 37 near the upper end of the reversing path 36 in FIG. Is transported to the side. When the recording paper is placed on the manual paper feeding device 83 as described above, the recording paper is detected by the sensor 87. In such a case, even when the paper feed cassette 29 is mounted in the LED printer 21, the paper feed roller 30 does not operate as described later, and the paper feed from the manual paper feed device 83 has priority. Is executed.

FIG. 4 is a plan view of the LED printer 21, FIG. 5 is a perspective view of the LED printer 21 as viewed from the left side of FIG. 3, and FIG. 6 is a front view showing a structure for detecting the waste toner box 99. Is.

A waste toner box 99 for collecting waste toner discharged from the process cartridge 73 mounted in the holding member 66 is provided at the rear end of the holding member 66 in FIG. It is detachably attached. On the other hand, support members 105, 106 projecting outward in the width direction are provided at both ends in the width direction of the lower housing 22.
Are formed respectively. On the support member 105 on the side where the waste toner box 99 is provided, a rectangular tube-shaped power supply member 107 that projects upward is provided. The power feeding member 107 is hollow, and a leaf spring-shaped connection terminal (not shown) protruding downward from the process cartridge 73 mounted on the holding member 66 is inserted into the inside thereof to conduct electricity.

Inside the power supply member 107, there is provided a coil-spring-shaped first power supply piece 108 which comes into contact with the connection terminal of the process cartridge 73 and supplies electric power for discharging to the charger 81 in the process cartridge 73. To be To the power supply member 107, toward the discharged toner box 99,
As an example, a waste toner box detection switch (hereinafter abbreviated as detection switch) consisting of a micro switch, etc. 1
10 are provided.

That is, when the upper housing 23 is closed with respect to the lower housing 22 and this operation causes the waste toner box 99 to descend downward in FIGS. 3 and 5, the waste toner box 99 causes the detection switch 110 to move.
The actuator 111 is pressed, and by reading the output of the detection switch 110 at this time, it is detected that the waste toner box 99 is attached to the holding member 66. Further, as shown in FIG. 3, a pressing piece 227 protruding toward the front side of the paper surface of FIG. 3 is provided at the widthwise end portion of the upper housing 23.
Is provided and separates / presses against the cover switch 217 when the upper housing 23 is opened / closed. The output of the cover switch 217 detects the open / closed state.

Further, on the supporting member 105, a rectangular cylindrical power feeding member 224 is also erected on the upstream side of the power feeding member 107 in the transport direction A1. The upper end portion of the power feeding member 224 is formed to extend inward in the width direction and then to the downstream side in the transport direction A1. A power feeding piece 225 is disposed in the crank-shaped upper end portion of the power feeding member 224. A connection terminal (not shown) provided at the lower end portion of the process cartridge 73 is brought into contact with the vicinity of the tip of the power feeding piece 225 and conducts when the upper housing 23 is closed. The other end of this connection terminal is connected to a developing roller 76 provided in the process cartridge 73, and applies a developing bias voltage to the developing roller 76.

FIG. 7 is a system diagram of the photosensitive drum 77 and the charger 81. In this embodiment, the shaft portion 1 of the photosensitive drum 77
12 is connected to ground potential. On the other hand, the discharge wire 113 of the charger 81 is -5 from the power feeding member 107 as an example.
A voltage of 00V to -800V is supplied. The shield case 114 of the charger 81 is connected to the ground potential together with the shaft 112.

FIG. 8 is a sectional view of the process cartridge 73. The process cartridge 73 accommodates the toner box 74 in the housing 75 described above. The housing 115 of the toner box 74 has a downwardly convex shape corresponding to the shape of the housing 75 of the process cartridge 73, and the toner storage portion 1 is opened upward.
16, a toner replenishing hole 117 is formed downward on the downstream side of the toner storage portion 116 in the conveying direction A1, and toner made of a porous material such as sponge is provided at a position to close the toner replenishing hole 117. A supply roller 118 is provided having an axis line that is perpendicular to the transport direction A1. On the other hand, in the toner storage portion 116, the toner stored in the toner storage portion 116 is stored in the cam 226 by the rotation of the cam 226.
A toner moving member 119 that is swung by the pressing force of the peripheral surface thereof and moves toward the toner supply roller 118 is provided. The toner moving member 119 is driven to make a reciprocal angular displacement about the shaft 120.

On the other hand, below the toner replenishing roller 118 of the process cartridge 73, the toner replenishing roller 1 is provided.
A sub-agitator 121 for moving the toner from 18 to the developing roller 76 side is provided. Sub agitator 121
The toner moved by the agitator 78 is further moved to the developing roller 76 side by the agitator 78, and the carrier and the toner stored near the developing roller 76 in the housing 75 of the process cartridge 73 are mixed to be developed as a developer. Supply to the roller 76.

(2) Electrical Configuration of LED Printer The electrical configuration of the LED printer 21 having such a basic configuration is shown in FIG. LED printer 21
A control unit 122 surrounded by a chain double-dashed line in FIG.
2, the print data DT, the clock signal CK1,
The LED head 82 to which the latch signal LT and the plurality of strobe signals STB are input, and the LED printer 21.
The charger 81 for charging the surface of the photosensitive drum 77 of
And the transfer discharger 100 and the fixing device 46,
Further, an electromagnetic plunger 125 for driving / stopping the carrying roller 86 of the manual paper feeding device 83 according to the output of the sensor 87, and each driving mechanism of the LED printer 21 (registration roller 38, photosensitive drum 77, pressure roller 48). etc)
A motor 126 that supplies rotation to the sheet feeding roller 30 and an electromagnetic device 124 that causes a clutch device that transmits / blocks rotation from the motor 126 to the sheet feeding roller 30 to perform the switching operation.

Further, the control unit 122 is provided with the sensors 3
3, 39, 51, 87 and the cover switch 217,
A cassette switch 218 that detects whether or not the paper feed cassette 29 is mounted, a toner motor 214 that drives the toner moving member 119 to perform a reciprocal angular displacement, a size sensor 213 that determines the type of the paper feed cassette 29, a thermistor 147 of the fixing device 46, and The detection switch 110 is connected.

The control unit 1 of such an LED printer 21
A host computer 127 is connected to 22 and a key input device 128 connected to the host computer 127.
A signal necessary for the operation of the LED printer 21 is supplied from the host computer 127 to the controller 122, and the printing operation is executed. A display unit 129 including, for example, a liquid crystal display element is connected to the control unit 122, and as will be described later, internal recording when a paper jam occurs when the LED printer 21 performs a printing operation. Operations such as displaying the number of retained paper sheets are performed. Further, the print key 229 is connected so that the printing operation can be executed.

The control section 122 is supplied with the clock signal CK2 from the oscillation circuit 168 and the image controller 13 is supplied.
0, the operation control of various drive mechanisms of the LED printer 21, the light emission operation control of the LED head 82, etc., and the engine controller 131 to which the clock signal CK3 is supplied from the oscillation circuit 228 is provided. The engine controller 131 includes a timer 132 and a first general-purpose counter 21.
5 and a second general-purpose counter 216, to which a ROM (Read Only Memory) 133 in which programs and the like that define the operation are stored is connected. On the other hand, outputs of various control signals and the like from the engine controller 131 are output to the LED head 82 and the like via a gate array 134 having a configuration described later.

FIG. 9 is a block diagram showing a structure for detecting the opening / closing operation of the upper housing 23. In this embodiment,
A cover switch 217 is provided that is turned on / off according to the opened / closed state of the upper housing 23. The cover switch 217 connects / disconnects the motor 126 or the charger 81 and the like with the power supply voltage V0 such as 24V. The output of the cover switch 217 is the motor 126.
Is supplied as a power supply voltage to the resistor 13
The voltage is divided by 6, 137 and connected to the inverting input terminal of the comparator 138. To the non-inverting input terminal of the comparator 138, the power supply voltage V1 (+ 5V as an example) is divided by the resistors 139 and 140, and the divided voltage is input as a reference voltage.

That is, the comparator 138 compares the voltage from the cover switch 217 when the upper housing 23 is opened (close to 0 V as an example) with a reference voltage which is a set voltage, and the upper housing 23 is released from the closed state. It detects that it is in a state. As a result, the engine controller 131 saves various data corresponding to the operation state of the LED printer 21 at that time, and stops the control operation, as described later. Further, when the upper housing 23 is opened and the cover switch 217 is cut off, the cover switch 2
The supply of drive power to the motor 126, the charger 81, etc. connected to the power supply voltage V0 via 17 is cut off. That is, the cover switch 217 has a function of interrupting the supply of drive power to the drive mechanism such as the motor 126 and the various components that perform an electrical operation when the upper housing 23 is in the released state, and the engine controller 1
It also has a function of sending a detection signal corresponding to the open state of the upper housing 23 to the unit 31.

FIG. 10 is a block diagram showing the electrical configuration of the LED head 82. As shown in FIG. 1, the LED head 82 receives the power supply voltage + B and the strobe signal STB from the engine controller 131 via the gate array 134.
1 to STB4, the latch signal LT, the clock signal CK1 and the image data DT in the form of serial data are supplied to realize a light emitting operation corresponding to the image data DT. The image data DT and the clock signal CK1 are input to the shift register 141 having the same number of bits as the number of LED elements 144 provided in the LED head 82, and when the input of the image data DT of the number of bits is completed, the latch signal L is input.
T is input and the image data DT of the shift register 141 is input.
Are stored in the latch circuit 142 having the same number of bits as the shift register 121.

The output of each bit of the latch circuit 142 is
The strobe signals STB1 to STB4 are input to the AND circuit 143, respectively. The output terminal of each AND circuit 143 is L
Each LED1 is connected to the ED144's chassis.
The anode of 44 is connected to the power supply voltage + B. In this circuit example, when the latch circuit 142 outputs a logic "0", that is, a low level trigger signal, and then maintains the high level, the strobe signals STB1 to STB are generated.
When 4 becomes a high level, a current flows through the corresponding LED element 144 to emit light.

FIG. 11 is a block diagram showing a configuration related to the temperature control of the fixing device 46. LE of this embodiment
The D printer 21 manages the temperature management of the fixing device 46 by software control as described later, but when the CPU (central processing circuit including a microprocessor) 145 provided in the engine controller 131 runs out of control, the fixing is performed. It becomes impossible to manage the temperature of the device 46 by software, and the heating element (halogen lamp) 1 shown in FIG.
The temperature of 46 may rise abnormally, causing thermal damage, smoke emission, or fire. Therefore, in the LED printer 21 of the present embodiment, the temperature of the heating element 146 is detected with the configuration shown in FIG. 11, and when an abnormally high temperature is detected, the CPU 145 is forcibly reset as a circuit operation. There is.

The temperature of the heating element 146 depends on the power supply voltage V1.
(5V as an example) is output as a voltage divided by the thermistor 147 and the resistor 148, input to the analog / digital converter 150 via the amplifier 149, converted into digital data, and input to the CPU 145. To be done.

On the other hand, the divided voltage from the thermistor 147 is input to the inverting input terminal of the comparator 152, and the reference voltage generating circuit 153 is input to the non-inverting input terminal of the comparator 152.
A predetermined voltage is input from. Reference voltage generation circuit 1
The reference voltage output from 53 is selected as a voltage level corresponding to an abnormally high temperature of the heating element 146.

When the thermistor 147 detects an appropriate temperature range, the engine controller 131 outputs a temperature management control signal from the gate array 134 to the transistor 154, and the heating element 146 is controlled via the photocoupler 155. TRIAC 156 connected in series to a circuit connected to a power supply voltage V2 (100V AC as an example)
Control signal is output to. Fuse 15 in this series circuit
7 is provided.

In the configuration shown in FIG. 11, the runaway of the CPU 145 is detected by the well-known watchdog timer circuit 151.
When the runaway of No. 5 is detected, a reset signal is generated and the driving of the engine controller 131 is stopped. However, as will be described later, the watchdog timer circuit 151 may not be able to detect the runaway of the CPU 145 depending on the contents of the runaway of the CPU 145.

That is, in this configuration example, even if the CPU 145 runs out of control and the fuse 157 does not blow even if the heating element 146 becomes abnormally high in temperature, the heating element 14 does not blow.
It is intended to stop the supply of the driving power to the No. 6 unit.
To this end, the output of the comparator 152 is the transistor 1
It is input to the base of 59. The output of the transistor 159 is input to the base of the transistor 160, and the transistor 160 applies the power supply voltage V1 to the base of the transistor 161 as the power switch of the motor 126 and the base of the transistor 154 as a bias voltage.
The output of the comparator 152 is a low active reset signal / R to the CPU 145 and the gate array 134.
It is input as S (hereinafter, “/” is used in the meaning of negative logic).

That is, if the output of the thermistor 147 corresponds to an appropriate temperature range, the comparator 152 outputs a high level signal, the transistor 159 is in a conductive state, and the transistor 160 is in a conductive state. As a result, a high-level bias voltage is applied to the transistors 161, 154, and a control signal from the gate array 134 under the control of the CPU 145 is applied to the transistor 161 or the transistor 154 to drive the motor 126 or the heating element 146. To be done.

When the output of the thermistor 147 exceeds the upper limit value indicated by the reference voltage generation circuit 153, the comparator 152 outputs a low level signal and the transistors 159 and 16 are output.
0, and CPU 145 and gate array 13
4 is forcibly reset by the reset signal / RS. As a result, the control signal from the gate array 134 is stopped, the transistors 161 and 154 are cut off, the motor 126 is stopped, and the supply of drive power to the heating element 146 is stopped.

That is, in the LED printer 21 having such a configuration, the CPU 145 and the gate array 134 are reset while the fuse 157 is not blown when the CPU 145 runs out of control and the heating element 146 becomes abnormally high temperature. The driving of the heating element 146 is stopped.
As a result, as compared with the case where the control of the heating element 146 is performed only by the program control by the engine controller 131, the control of the heating element 146 becomes impossible and the heating element 14
It is possible to prevent the risk of causing damage due to heat, smoking, fire, or the like, which causes abnormal temperature rise in 6.

The operation of the CPU 145 and the gate array 134 is performed when the input power supply voltage V1 is within a proper range such as ± 1% of the proper operating voltage DC5V as an example.
Achieve the designed behavior. On the other hand, for example, LE
When the power source of the D printer 21 is turned on, the period until the power source voltage V1 rises to a value in the appropriate voltage range, and the LED
When the power supply of the printer 21 is cut off, the proper power supply voltage is not supplied to the CPU 145 during the transition period in which the power supply voltage V1 falls below the proper voltage range. With these, the CPU 145
Causes a malfunction.

CP in the transition period of such power supply voltage
In order to prevent the malfunction of U145, in this embodiment, the output of the voltage monitoring circuit 158 is set to the comparison circuit 15
2 is connected to the output terminal of the transistor 159 to turn on / off the output of the comparison circuit 152 or the CPU.
The same operation as the output of the reset signal to 145 and the gate array 134 is performed.

FIG. 12 is a diagram showing a part of the contents stored in the ROM 133. As described above, the LE of this embodiment is used.
In the D printer 21, temperature control of the fixing device 46 is performed by program control by the CPU 145 of FIG. The present embodiment is characterized in that two operation modes are set when the temperature control of the heating element 146 is performed by program control.

The first operation mode is the temperature raising mode, and L
It is used when the ED printer 21 is turned on, when the temperature is raised from a cooling state to a predetermined heat retention temperature, or when the temperature is raised from the heat retention temperature to a drive temperature at which a printing operation is actually performed.

The duty table 163 stored in the ROM 133 is used in the temperature increasing mode described above, and temperature data measured by the thermistor 147, for example, temperatures of 100 ° C., 110 ° C., 120 ° C., 170 ° C., etc. Energization duty data Dd = u1 / 5 corresponding to T
0, u2 / 50, ..., Un / 50, etc. are stored. In the LED printer 21 of the present embodiment, the energization cycle of the heating element 146 is set to 1 second as an example, and the energization cycle of 1 second is divided into 50 equal parts to the data ui (i = 1, 2, ...) As an example.
Values such as 0, 25, 22, 20, ... Are set. That is, the energization cycle of this embodiment is 50/5 during the energization cycle of 1 second.
The energization duty decreases as the temperature T rises from 0 second = 100% duty. That is, the current temperature T
The lower the temperature, the faster the temperature rises, and the closer the temperature T approaches the drive temperature, the more the temperature rises gradually.
As a result, it is possible to prevent the fixing device 46 from overheating due to the temperature overshoot during the temperature raising operation.

On the other hand, the second operation mode is the heat retention mode. The conduction / interruption state of the triac 156 is controlled so that the temperature of the heating element 146, that is, the temperature detected by the thermistor 147 is the heat retention temperature.

FIG. 13 is a system diagram showing a configuration related to the operation of reading signals from the sensors 33, 39, 51, etc., FIG. 14 is a block diagram showing a concrete example of this configuration, and FIG. It is a figure which shows an example of the memory content of ROM133. In this embodiment, various types 33, 39, 51,
A signal from the 87 or the thermistor 147 is sent to the CPU 14 via the gate array 134.
Read by 5. A processing routine corresponding to the state of the signal is read from the ROM 133 and executed. In the present embodiment, it is possible to speed up such operation.

The address data in the ROM 133 has a 6-bit configuration, and the CPU 145 outputs the remaining 5-bit address data AD4 to AD0 excluding the most significant bit AD5 of the 6-bit address data AD5 to AD0. On the other hand, the gate array 134 has a plurality of input ports 16 to which signals from the various sensors are respectively supplied.
4 is provided, and the signal from each input port 164 is input to the data selector 165 to select one of them. The selected signal is input as the most significant bit AD5 of the address data of the ROM 133.

The operation of selecting which signal in the data selector 165 is performed by the higher 4 bits of the 5-bit address data AD4 to AD0 output by the CPU 145.
It is designated by bit address data AD4 to AD1. That is, the 4-bit address data AD4 ...
By using AD1, 16 from various sensors
Any one of the types of signals can be selected.

On the other hand, in the ROM 133, as an example, the processing routine corresponding to the case where the sensor 33 is in the off state is written from the address 0A, and the processing routine corresponding to the off state of the sensor 39 is written from the address 0B. Similarly, the processing routine corresponding to the off state of each sensor is written from the corresponding address. The processing routine corresponding to the ON state of the sensor 33 is written from the address 1A, and similarly, the processing routine corresponding to the ON state of the sensors 39 and 51 is the addresses 1B and 1C, respectively.
Written from each. Here, the address 0A, 0
B, 0C and 1A, 1B, 1C are not hexadecimal notation, but are symbols representing the 5-bit address data AD4 to AD0, respectively. Therefore, the ROM 133
The lower 5 bits of the address data AD4 to AD0 in the 6 bits of address data AD5 to AD0 are data for identifying the sensors 33, 39, 51 ,. Further, each processing routine has a return instruction or the like written at the end of the instruction sequence, and is executed for each processing routine. In this embodiment, each processing routine is composed of 2 bytes.

That is, the CPU 145 uses the address A,
5-bit address data AD4 to A corresponding to B and C
When D0 is output, as described above, the upper 4 bits AD4 to AD1 are input to the gate array 134,
One input port 16 corresponding to the data selector 165
Select 4. That is, as an example, the input port 164 to which the signal of the sensor 39 is input is selected. At this time, the 6-bit address data AD5 to A of the ROM 133
Lower 5 bits of address data AD4 to AD of D0
0 is the address data A output from the CPU 145.
D4 to AD0 correspond to each other. Furthermore, ROM13
The highest level address data AD5 of No. 3 corresponds to the high level or low level signal from the corresponding input port 164 from the data selector 165.

Therefore, when the CPU 145 tries to read the signal from the sensor 39, either of the address 0B or the address 1B shown in FIG. 15 corresponding to either the high level signal or the low level signal from the data selector 165. Will be confirmed. Ie CP
When the signal from the sensor 39 is to be read, the U145 automatically executes the processing routine corresponding to the high level or low level of the output of the sensor 39 by executing the instruction GOTO processing routine address lower 5 bits data. You can do it. For reading signals from other sensors, the address data AD4 to
This is performed by sequentially changing AD0 to the corresponding contents.

An example compared with this embodiment is the CPU 145.
A plurality of instructions READ A, PORT TEST 1 when an output signal of a sensor or the like is read from one of the input ports 164 via the gate array 134 and the processing routine of the ROM 133 is executed corresponding to the state. , A GOTO ON, and a plurality of instructions at the processing routine address are executed. In such cases,
The number of instruction steps required to execute the processing increases, and the data processing speed decreases.

In this embodiment, the CPU 145 outputs different address data for each sensor, and based on this, the data selector 165 outputs a signal from the corresponding sensor to the ROM 133 as a part of the address data. I am trying to do it. Therefore, the processing routine based on the output signals of the sensors 33, 39, 51 shown in FIG. 15 is individually executed.

FIG. 16 is a system diagram showing a configuration for outputting signals to the electromagnetic plunger 125 and the electromagnetic device 124 of the LED printer 21. FIG. 17 is a diagram for explaining the main write operation. Generally, when a CPU outputs a high level or low level signal to the outside, the CPU
A single address is set to the output port or the output integrated circuit element of the electronic device including the Is set in the output port or the output integrated circuit element, and is output to different output destinations such as a solenoid or a motor switch for each bit, for example.

At this time, in order for the CPU to set data in the data bus, it is necessary to use a general-purpose register of the CPU and set a plurality of bits of data in which a predetermined bit becomes high level or low level in the general-purpose register. In this way, bits other than the target bit will be rewritten. Therefore, the CPU needs to separately store the data of the output port or the output integrated circuit element before the change and perform the arithmetic processing of the logical sum or the logical product.

On the other hand, in the present embodiment, the CPU 145 uses the 5-bit address data AD4 to AD0 as an example,
Input to the gate array 134 via the address bus 166. In the gate array 134, the data selector 165
To the address data AD4 to AD0, and one of the 16-bit output ports OP1 to OP16 is selected by the upper 4-bit address data AD4 to AD1 as an example provided in the data selector 165.
The lowest address data AD0 is output to the selected output port OPi (i = 1 to 16). As an example, the output port OP1 is connected to the base of a transistor 161 for controlling energization / interruption of the motor 126, and the output port O1
The base of a transistor 167 that connects and disconnects the electromagnetic plunger 125 is connected to P2. The remaining output port OPi is connected to, for example, a high voltage generating circuit that outputs a high voltage to the charger 81 or the transfer discharger 100 shown in FIG.

That is, when the CPU 145 attempts to write a high level signal or a low level signal to any one of the output ports OPi, it does not need to set any data on the data bus. As an example, when a certain output port OPi is set to a low level, AD0 = "0" is set, and WRITE (AD (OPi) + AD0), Da AD (OPi); 4-bit address data AD4 to AD1 Da corresponding to the output port OPi. You can execute arbitrary data. When the output port OPi is set to the high level, AD0 = "1" and WRITE (AD (OPi) + AD0), Da may be executed.

Therefore, it is possible to eliminate the need to perform the multi-step processing as described above, and it is possible to significantly speed up and simplify the operation of outputting the control signal to the outside by the CPU 145.

FIG. 18 shows the L in the LED printer 21.
6 is a block diagram of a configuration for outputting an LED clock signal CK1 which is a shift clock signal to the ED head 82. FIG.
In the LED printer 21 of the present embodiment, as shown in FIG. 1, the control unit 12 that controls the operating state of the LED head 82.
The image controller 2 includes an image controller 130 and an engine controller 131. As described above, the image controller 130 is provided with the oscillation frequency f1 = 1 from the oscillation circuit 168 including a crystal oscillator as an example.
The clock signal CK2 of 4.9 MHz is input. The image controller 130 operates based on this clock signal CK2.

On the other hand, in this embodiment, the engine controller 131 is provided with a clock signal C from the oscillation circuit 228.
K3 is input and the operation is performed. At this time, the image data in the output operation of the LED printer 21 is output from the CPU provided in the image controller 130, and the generation and the output of this image data are performed independently of the generation timing of the clock signal CK3. Therefore, the LE of the present embodiment is divided by dividing the clock signal CK3.
When the shift clock CK1 of the D head 82 is created,
In some cases, the shift clock CK1 and the output image data cannot be properly synchronized. That is, the configuration shown in FIG. 18 is used when such proper synchronization cannot be achieved.
The shift clock C based on the clock signal CK3
It is intended to adjust the phase of the generation timing of K1.

Hereinafter, FIG. 18 will be referred to. The oscillator circuit 2
The clock signal CK3 from 28 is input to the gate circuit 169 together with the horizontal synchronizing signal BD from the CPU 145. It is input to the frequency divider 171 as a clock signal. The count value of the counter 170 is input to one input terminal of the comparator 172, and the other input terminal of the comparator 172 receives the numerical data “1”, “3”, “5” and “7” from the data selector 173. Either is entered. Signals from two dip switches 174a and 174b externally connected to the gate array 134 as an example are input to the data selector 173.

That is, the DIP switches 174a, 17
4b is independently set to either an on state or an off state, so that the dip switch 174
a and 174b can instruct the data selector 173 to select any of the four types of numerical data. This instruction is given by the DIP switches 174a and 174.
When the on / off state in b corresponds to the logic “1” and “0” of digital data, the DIP switch 174
As the digital data corresponding to the combination of ON / OFF states of a and 174b increases, the data selector 17
The numerical data specified in 3 are chosen to increase progressively. That is, the comparator 172 uses the counter 170.
Is compared with the numerical value set by the data selector 173, and the frequency divider 1
A control signal is output to 71 to start the frequency dividing operation.

FIG. 19 is a block diagram showing a specific example of the configuration shown in FIG. In FIG. 19, the gate circuit 169 in FIG. 18 is omitted. Counter 170 is implemented as an 8-bit counter and comparator 172 is also an 8-bit counter.
It is implemented as a bit comparator. On the other hand, the horizontal synchronizing signal BD is input to the flip-flop 175.

The output of the flip-flop circuit 175 is input to the enable terminal of the counter 170 and the counter 17
0 is activated and is input to the AND circuit 176. The output of the AND circuit 176 is input to the enable terminal of the frequency divider 171. The flip-flop circuit 17
5 and the AND circuit 176 form the gate circuit 169 in FIG. The clock signal CK1 output from the frequency divider 171 is input to the 12-bit counter 177, and the output of the counter 177 is also input to one input terminal of the 12-bit comparator 178. The other input terminal of the comparator 178 receives the data from the 12-bit register 179 to which the data is set by the CPU 145. The comparison result of the comparator 178 is input to one input terminal of the flip-flop circuit 180, and
It is input to the other input terminal of the AND circuit 176. Meanwhile, the latch signal LT output from the CPU 145 described with reference to FIG. 10 is input to the other input terminal of the flip-flop circuit 180.

The reset signal RS is input to the gate array 134 of FIG. 19, and the reset signals are set to the comparator 172 and the flip-flop circuits 175 and 180, respectively.

FIG. 20 is a block diagram showing a configuration example of the gate array 134 for generating the four types of strobe signals STB1 to STB4 described with reference to FIG. In this configuration example, the clock signal C from the oscillation circuit 228 is used.
As an example obtained by dividing K3, a 0.47 MHz clock signal CK4 is input, and an 8-bit counter 1
It is input to 81 as a clock signal. Counter 181
Is also input to one input terminal of the 8-bit comparator 182, and the other input terminal of the comparator 182 has the C
The data from the 8-bit register 183 in which the preset data is written by the processing of the PU 145 is read.

The count value of the counter 181 is the register 1
When the comparator 182 detects that the set data of 83 matches, the comparator 182 inputs the clock signal to the 8-bit counter 184. On the other hand, the horizontal synchronizing signal BD from the CPU 145 is input to the gate array 134 and is input to the flip-flop circuit 185. The flip-flop circuit 185 performs a toggle operation in which the output switches between a high level and a low level at the timing of the falling edge of the horizontal synchronizing signal BD.

The output of the flip-flop circuit 185 is A
It is input to one input terminal of the ND circuit 186, and the other input terminal of the AND circuit 186 has the counters 184 to 1
A low-level signal output at each clock input is input. The output of the AND circuit 186 becomes low level each time this low level signal is input, the counter 181 is reset, and the count value is returned to 0 as an example.

The reset signal / RS is input to the gate array 134, and the flip-flop circuit 185 is provided.
And is input as a reset signal to the counter 184. The reset signal / RS is generated in synchronization with the counter operation of the counter 184 each time 4 clocks are input from the comparator 182. At this time, the counter 184
Is output to the energizing distribution circuit 187, and the comparator 182
The strobe signals STB1 to STB4 are sequentially generated for each period corresponding to the cycle of the clock signal from.

According to this structure, the strobe signals STB1 to STB4 are obtained by dividing the signal from the counter 184 by the energizing distribution circuit 187 for each same period. Therefore, as compared with the case where strobe signals STB1 to STB4 that define mutually different energizing periods are generated by individual circuits, the configuration required for generating strobe signals can be significantly simplified.

(3) Transition Relationship between Various Operations In the following description, the drawings of FIGS. 1 to 20 described above will be referred to as appropriate.

FIG. 21 shows the LED printer 21 of this embodiment.
FIG. 7 is a transition diagram showing transition states of the entire operation from power-on of the device to the end of the reset operation. When the LED printer 21 is turned on, the image controller 130, the engine controller 131, or the gate array 134 is turned on.
A transition is made to a preparation state 188 for setting various initial states such as. In the preparation state 188, various initial settings as described later are completed, the fixing device 46 shown in FIG. 2 raises the temperature to a predetermined standby temperature, and the toner concentration near the developing roller 76 in the process cartridge 73 becomes within an appropriate range. When it is confirmed that the process cartridge 73 is present and the process cartridge 73 is properly attached, the process shifts to the standby state 189.

In the standby state 189, the LED printer 21
1 is set to a state in which printing operation is possible,
It waits for the input of the print start signal PRNT from the image controller 130 shown in FIG. The print start signal PRNT
Is input, the printing operation state 190 is entered, and when printing is completed, the state returns to the standby state 189. Here, in the preparation state 188, the standby state 189, and the printing operation state 190, when the upper housing 23 shown in FIG. To error handling status 19
Move to 1. In the error processing state 191, when the failure state or the paper jam state is repaired and the upper housing 23 is closed, the operation state of the LED printer 21 returns to the preparation state 188.

FIG. 22 is a transition diagram showing details of the printing operation state 190. In the standby state 189, when the print start signal PRNT is input from the image controller 130 as described above, the engine controller 131
1 shifts to the introduction state 192, the fixing device 46 is heated to an operating temperature higher than the standby temperature, and various rollers such as the sheet feeding roller 30 shown in FIG. The motor 126 is started and electric power is applied to the charger 81. When the fixing device 46 has risen to the operating temperature, the first printing state 193 is entered. In the first printing state 193, the recording paper is taken out from the paper feed cassette 29 by the paper feed roller 30, or is fed from the manual paper feed device 83 to the transport roller 86.
Take in by rotating. Figure 1 with the recording paper loaded
The control signal VSRQ shown in FIG.
And outputs a page synchronization signal VSY which is a synchronization signal for one page of image data.

When the page synchronization signal VSY is input from the image controller 130 to the engine controller 131, the operation state shifts to the second print state 194, and the operation state shown in FIG.
The transfer discharger 100 is used to transfer the toner image from the photosensitive drum 77 to the recording paper. When a predetermined time elapses in this state and the sheet can be fed for printing the next page, the printing standby state 195 is entered. In the print standby state 195, when the printing is completed and the operation of the transfer discharger 100 is stopped, the state is shifted to the first stop state 196, the recording sheet after transfer is fixed by the fixing device 46, and then the discharge roller 5
The operation up to discharging to the outside of the machine is carried out using 8, 59; 64, 65.

When the paper discharge is completed in the first stop state 196,
The second stop state 197 is entered, the print start signal PRNT is stopped from the image controller 130 shown in FIG. 1, the supply of drive power to the charger 81 is stopped, and the third stop state 198 is entered. In the third stopped state 198, the motor 126 and the toner motor 214 shown in FIG. 1 are stopped, and the temperature of the fixing device 46 is lowered from the operating temperature to the standby temperature lower than the operating temperature. When the motor 126 stops, the operating state of the LED printer 21 returns to the standby state 189.

When the print start signal PRNT is input from the image controller 130 in the print standby state 195 and the first stop state 196, the processing shifts to the first print state 193 and the above-mentioned processing is performed. .
On the other hand, when the print start signal PRNT is similarly input from the image controller 130 in the second stop state 197, the print restart state 199 is entered, and the second stop state 1 is set.
At 97, the drive power is once again supplied to the charger 81 whose drive power has been cut off, and the first printing state 193 is entered to perform the printing operation again.

In the LED printer 21 of this embodiment, four types of print modes are set. Type 1 print mode is 1
The printing operation ends when printing on one sheet of recording paper.
Standby state 189, introduction state 192, first printing operation state 1
93, a second printing operation state 194, a print standby state 195,
After the first stop state 196, the second stop state 197 and the third stop state 198, the process returns to the standby state 189.

The second type print mode is an operation in which printing is not completed for each recording sheet, and after the second stop state 197 is reached in the operation sequence of the first type print mode, the print restart state 199 is set. After that, the first printing operation state is entered. This printing mode has the slowest printing speed in the continuous mode in which printing is continuously performed on a plurality of recording sheets.

In the third type print mode, in the operation sequence of the first type print mode, after reaching the first stop state 196, the third type print mode shifts to the first print operation state 193. This print mode is a continuous mode that is faster than the second type print mode. The fourth type printing mode is the printing mode with the fastest printing speed, and in the operation sequence of the first type printing mode, after reaching the print standby state 195, it immediately shifts to the first printing operation state.

FIG. 23 is a transition diagram for explaining the operation of selecting the paper feed state in the LED printer 21. When the LED printer 21 is powered on, the image controller 130 and the engine controller 131 are first set to the cassette mode 200 using the paper feed cassette 29. In this operating state, the sensor 87 provided in the manual paper feeding device 83 detects whether or not the recording paper is installed in the manual paper feeding device 83. If the recording paper is installed, the image controller 130 transmits a command to specify the manual paper feed to the engine controller 131, and shifts to the manual paper feed mode 201. Manual feed mode 201
When the sensor 87 detects that there is no more recording paper in the manual paper feeding device 83, the image controller 130 instructs the engine controller 131 to operate based on the paper feeding cassette 29, thereby causing the LED printer 21 to operate. The operation state of No. returns to the cassette mode 200.

FIG. 24 is a transition diagram for explaining the toner replenishing operation in the LED printer 21. When the LED printer 21 is powered on, the process cartridge 73 shown in FIG. 2 starts operating from a state where it is considered that the toner is full. Such proper toner state 20
In 2, when the toner sensor 104 detects a decrease in toner density, the toner replenishment state 203 is entered. In the toner supply state 203, the toner supply roller 11 shown in FIG.
8 is intermittently angularly displaced to replenish the toner in the toner box 74 to the agitator 78 side. At this time, the developing roller 76 and the photosensitive drum 77 are rotationally driven according to the operating state at this time, and the process cartridge 7
The toner in 3 is in a state of being successively consumed.

Even when such a toner replenishing operation state has passed a predetermined time, if the toner concentration in the process cartridge 73 detected by the toner sensor 104 is low, the toner replenishing state 204 is entered, and The operation of the mechanism that consumes toner, such as the developing roller 76 and the photosensitive drum 77, is stopped. In this state, the toner replenishing roller 118 is rotationally driven to replenish the toner in the toner box 74 to the agitator 78 side. If the toner concentration detected by the toner sensor 104 is insufficient even if such a replenishing operation is continuously performed for another predetermined time, the engine controller 131 causes the toner box 74 to run out of toner or the toner box 74. Assuming that the process cartridge 73 is not mounted on the process cartridge 73, the process proceeds to the toner-free state 205, and a message such as toner exhaustion is displayed.

If it is determined in the toner replenishment state 203 or the toner replenishment state 204 that the toner density detected by the toner sensor 104 is in an appropriate state, the toner proper state 202 is entered. That is, in the LED printer 21 of the present embodiment, when the toner in the toner box 74 is replenished to the agitator 78 side, the toner replenishing roller 118 is rotated and replenished while the developing roller 76 and the image roller 77 are rotationally driven. I do. If toner shortage is detected even by such a replenishment operation,
As described above, the drive mechanism is stopped and further replenishment is performed.

That is, in this embodiment, the toner in the process cartridge 73 is reduced due to the execution of the printing with a relatively large amount of white background, and the printing that consumes the toner rapidly is performed, for example, the printing that is close to the solid black is continuously performed. The rapid reduction of the toner in the process cartridge 73 due to the execution and the emergency state such as the non-mounting of the toner box 74 or the toner exhaustion in the toner box 74 are discriminated to take the countermeasures. As a result, it is possible to make a detailed response to the lack of toner in the process cartridge 73, and it is possible to significantly improve the usability of the LED printer 21.

FIG. 25 is a transition diagram relating to the control of the fixing device 46. When the power of the LED printer 21 is turned on,
The LED printer 21 sets the fixing device 46 to the table mode 2
Operate at 06. That is, the temperature of the fixing device 46 is raised from the cooling state to the standby temperature by using the duty table 163 described with reference to FIG. In the table mode 206, when the temperature measured by the thermistor 147 shown in FIG. 11 of the fixing device 46 becomes equal to or higher than a predetermined reference temperature lower than the standby temperature, the threshold mode 207 is entered. The threshold mode 207, which will be described in detail later, is an operating state in which control is performed so that the temperature of the fixing device 46 is maintained at the standby temperature or the operating temperature. In the operating state of the threshold mode 207, the temperature of the fixing device 46 is lower than the standby temperature or the operating temperature, and is lower than the temperature width at the time of shifting from the table mode 206 to the threshold mode 207 by a second width. When the temperature becomes lower than the reference temperature, the table mode 206 is entered,
Perform a rapid temperature rise.

In the operating state of the table mode 206 or the threshold mode 207, for example, when the power of the LED printer 21 is cut off or the upper housing 23 shown in FIG. 2 is opened, the driving power is supplied to the fixing device 46. Is stopped. In such a case or when an error is detected in the control of the fixing device 46, the stop mode 208 is entered. When the energization of the fixing device 46 is started again in the stop mode 208, the process shifts to either the table mode 206 or the threshold mode 207 based on the temperature measured by the thermistor 147 at that time, and the fixing device 46 is operated. Perform temperature control.

FIG. 26 is a transition diagram showing an error processing operation state of the LED printer 21. In the LED printer 21 of the present embodiment, when an error such as excessive temperature rise or inability of temperature rise of the fixing device 46 is detected, or the exhaust fan motor 45
26 (1) when the lock state of is detected.
The operating state shifts to the all-stop state 209 as shown in FIG. In the total stop state 209, the motor 126 shown in FIG. 1 is stopped, the supply of drive power to the charger 81 is cut off, and all the drive mechanisms of the LED printer 21 are stopped. However, when an error of the fixing device 46 or an error of the exhaust fan motor 45 is detected, a flag relating to various printing conditions such as the required number of printed sheets or the number of printed sheets of the LED printer 21, or print density, and the error are dealt with. The flag to be executed is saved and saved in the memory.

In this state, the infinite loop 210 is constructed and waits for repair work by the service person.

On the other hand, as shown in FIG. 26 (2), the LED
When the open state of the upper housing 23 shown in FIG. 2 is detected when the printer 21 is powered on, the operating state shifts to the total stop state 209. When the upper housing 23 is closed in the full stop state 209, the state shifts to the preparation state 188 described with reference to FIG. 21, and shifts to the standby state 189 under the conditions as described above. If a paper jam (sometimes referred to as a jam) occurs during operation of the LED printer 21, the state also shifts to the total stop state 209 and the jam release standby state 210
Then, the process waits until the upper housing 23 shown in FIG. 2 is opened and the jam clearance process is completed. Jam release is completed in the jam release standby state 210,
When the upper housing 23 is closed, the above-described preparation state 1
88, and then the standby state 189.

(4) Description of processing procedure of each operation (4a) Overall operation The processing procedure of the operation for realizing the various transition states described with reference to FIGS. Explained.

FIG. 27 is a flowchart showing the overall operation from power-on to execution of printing in the LED printer 21, and FIG. 28 is a time chart for explaining the operation related to power-on. When the LED printer 21 is powered on, the stack pointers of the image controller 130 and the engine controller 131 are initialized, and in step a2, the CPUs of the image controller 130 and the engine controller 131 are initialized as described below. In step a3, the initialization processing of the gate array 134, which will be described later, is performed.
In 4, the setting processing of various flags of the engine controller 131, which will be described later, is performed. At step a5, the engine controller 131 outputs the initialization completion signal PPRDY when the processing at steps a2 to a4 is completed, indicating that the image controllers 132 can communicate with each other. At step a6, an initial operation described later is executed. Here, the processing of the steps a1 to a6 is performed in the preparation state 188 shown in FIG.

In step a7, a standby process described later is performed, and in step a8, an introduction process described later is performed. The state in which the processes of steps a7 and a8 are performed is the standby state 189 shown in FIG. Next, a printing process is performed in step a9, and thereafter, the processes of steps a7 to a9 are repeatedly performed until the power of the LED printer 21 is cut off.

(4b) Circuit Protection in Transient State In the operation at power-on as described above, FIG.
As shown in 8 (1), the power is turned on at time t1, and as an example, the AC 100V power is supplied to the LED printer 21. At this time, as shown in FIG. 11, the circuit drive voltage V1 is applied to the CPU 145, the gate array 134, and the like.
(DC 5V as an example) is supplied. When the power supply is cut off at time t2, this drive voltage V1 is also cut off. The change in the drive voltage V1 shown in FIG. 28 (2) is described in detail in FIG.
8 (3). That is, even if the power switch is turned on at time t1, the driving voltage V1 actually rises in a ramp waveform and enters the voltage range ΔV in which the CPU 145 and the like can operate at time t3. Here, this voltage range ΔV is selected to be, for example, about 5V ± 5%. On the other hand, when the power supply is cut off at time t4, the driving voltage V1 falls below the voltage width ΔV at the time t2, which is slightly delayed from the time t4, gradually decreases in the ramp waveform, and reaches 0V at the time t5.

In the LED printer 21 of this embodiment, as shown in FIG.
The voltage monitoring circuit 158 shown in FIG. 1 monitors the fluctuation of the driving voltage V1 and outputs the reset signal / RS except when the driving voltage V1 is within the range of the voltage width ΔV.
When it is in the range of, the reset signal / RS is released. This reset signal / RS is output as a low active signal, which causes the transistor 1 shown in FIG.
59 is cut off, driving of the motor 126 and the heating element 146 of the fixing device 46 is stopped, and the CPU 145 and the gate array 134 are also reset. That is, when the drive voltage V1 is not within the voltage range in which the integrated circuit elements such as the CPU 145 used in the LED printer 21 of the present embodiment operate properly, these integrated circuit elements are reset to prevent malfunction. I am trying.

(4c) Synchronous Adjustment As described with reference to FIGS. 1 and 18, the clock signal CK defining the operation of the engine controller 131.
3 is supplied from the oscillation circuit 228 connected to the engine controller 131. Engine controller 131
To the image controller 130
D is output, and the image controller 130 receives this and outputs the print data DT for one line to the engine controller 131. On the other hand, the engine controller 131 outputs the horizontal synchronizing signal BD and the clock signal CK3 to the gate array 134. At this time, the gate array 134 uses the structure and operation described with reference to FIG. Head 8
Enter in 2.

In the LED printer 21 of this embodiment, the engine controller 131 does not generate the image data DT, but the image controller 130 generates the image data DT. Therefore, the engine controller 131
Is the image data DT from the image controller 130.
Is output to the LED head 82 via the gate array 134, the shift clock CK1 generated in the gate array 134 is output for each bit as shown in FIGS. 29 (1) and 29 (2). At the timing when the data is generated in the confirmed state, the proper data is stored in the shift register 141 shown in FIG. 10 in the LED head 82.

On the other hand, as shown in FIGS. 29 (3) and 29 (4), the image data DT is not in the defined logical state of logic "0" or logic "1" but in the transition period between them. The shift clock CK1 may be generated. In such a case, from the gate array 134 to the LED array 8
2 image data DT and shift clock signal C
Various control signals such as K1 are stored in the shift register 141 in an unstable logic state, which may result in erroneous printing.

In the present embodiment, in order to eliminate such a problem, two DIs are used as described with reference to FIG.
Using the P switches 174a and 174b, the data selector 173 selects one of the numerical data "1, 3, 5, 7".
Choose one. At this time, the clock signal CK3 is input to the counter 170 of FIGS. 18 and 19, but when the horizontal synchronizing signal BD is at the low level, the counter 17
0 is the reset state. When the horizontal synchronizing signal BD becomes high level, the flip-flop circuit 175 outputs a high level signal and inputs it to the counter 170, and the counter 17
Set 0 to active state.

As a result, the counter 170 performs a counting operation by the input of the clock signal CK3 and compares it with any one of the numerical data “1, 3, 5, 7” set by the data selector 173 in the comparator 172. To do. If the numerical data matches, the comparison circuit 172 outputs a low level signal, and the flip-flop circuit 17
5 is reset and the operation of the counter 170 is stopped. At this time, a low level signal is also supplied to the flip block 180.

At this time, the comparator 178 has the frequency divider 17
Shift clock CK with frequency from 1. to 1.86 MHz
12-bit counter 177 that counts 1 and CP
U145 compares the data set in the register 179 in which the number of bits of the shift register 141 is set, and if they match, the flip-flop circuit 180,
A low level signal is supplied to the AND circuit 176. As a result, the AND circuit 176 is cut off and the flip-flop circuit 180 is reset.

When the output of the comparator 178 is at the high level, the AND circuit 176 is in the conductive state, and the output of the flip-flop circuit 175 at the high level causes the frequency divider 17 to operate.
1 is set to the operating state. From the frequency divider 171 to FIG.
The start timing of the frequency dividing operation corresponds to each numerical data set by the data selector 173 of FIG.
As shown in (6) of the figure, the shift clock signal CK1 having a frequency of 1.86 MHz can be output by shifting by 2 clocks.

That is, as shown in FIG. 30 (7), the image data DT supplied to the engine controller 131 side from the image controller 130 is shown in FIG.
The shift clock signal CK1 of either (4) or FIG. 30 (5) may be selected. That is, in general, in an electronic circuit to which some signal is input, when a signal to be synchronized with the input signal is generated, when the signal to be synchronized is not generated in an appropriate phase based on the input signal, Even if a phase shift occurs between the two, the present invention can eliminate such a phase shift with high efficiency.

(4d) Simplification of Strobe Signal Generating Mechanism FIG. 31 is a timing chart showing the operation of the gate array 134 having the configuration shown in FIG. The gate array 134 shown in FIG. 20 has a 0.47 MHz clock signal CK.
4. The horizontal sync signal BD and the reset signal / RS are input. When the low active horizontal synchronizing signal BD as shown in FIG. 31 (1) falls to the low level, FIG.
The output of the flip-flop circuit 185 becomes high level, and the AND circuit 186 becomes conductive. When the output of the counter 184 to the AND circuit 186 is high level, the counter 181 is activated and the counting operation is performed by the clock signal CK4.

The count value of the counter 181 is previously shown in FIG.
1 (2) to each strobe signal STB1 shown in FIG.
~ Clock signal CK corresponding to the input period T1 of STB4
The number of clocks of 4 (for example, 4 clocks) is determined by the number of clocks set in the register 183. That is, when the counter 181 starts counting, the output of the comparator 182 becomes low level, the counter 184 outputs a high level signal to the AND circuit 186 and the energization distribution circuit 187, and the AND circuit 186 maintains the conductive state. The energization distribution circuit 187 outputs a high level signal.

The energizing distribution circuit 187 includes a counter 18
4 until the output of No. 4 is set by the output of the comparator 182, strobe signals STB1 to STB4 are sequentially and continuously generated as shown in FIGS. 31 (2) to 31 (5).

Such strobe signals STB1 to STB
When all the elapsed time over B4 has elapsed, the reset signal R
S is input, the counter 184 and the energization distribution circuit 18
A low-level reset signal is input to 7 to reset the flip-flop circuit 185. As a result, the operation of generating the strobe signals STB1 to STB4 is achieved.

Moreover, at this time, if a single signal is created for a total of four strobe signals STB1 to STB4,
Strobe signal STB is given by sequentially delaying this signal.
1 to STB4 can be generated. That is, the configuration for providing the generating circuit for each strobe signal STB1 to STB4 is not necessary, and the configuration can be simplified.

(4e) Details of Preparation Operation FIG. 32 shows the LED printer 21 of this embodiment shown in FIG.
28 is a timing chart of a preparation state from step a1 to step a6 shown in FIG. 27 after the power is turned on. When the power is turned on at time t1 in FIG. 32, the preparation process of steps a1 to a6 of FIG. 27 is performed as described above.

Step a1 is the image controller 130 and engine controller 13 of the LED printer 21.
For each of the stack pointers 1 and 2, initialization of each pointer for executing the subsequent processing is performed. Details of the setting process of the CPU 145 in step a2 are shown in FIG. In step b1 of FIG. 33, the setting and initialization of the input / output port of the CPU 145 and the scanning cycle of various sensors are set. Step b2
Then, the 1 ms timer 1 of the LED printer 21 shown in FIG.
32 is activated.

The gate array setting process is shown in FIG.
At step c1, the output states of the output signals from the various counters and various circuit parts provided in the gate array 134 are initialized. Each flag setting process in step a4 is shown in FIG. 35, and in step d1, the transmission state of the image controller 130 shown in FIG. 1 with the host computer 127 or the mutual communication state between the image controller 130 and the engine controller 131, etc. CPU 145 mounted on controller 130
The initial setting or internal operation flag is set for each of the various input / output signals related to. In step d2, since the temperature of the fixing device 46 is controlled in the LED printer 21, the threshold value set at each break point within the range of change in the measured temperature of the fixing device 46, which will be described later in detail, that is, the standby temperature described above. And a threshold value, which is the operating temperature, are set.

FIG. 36 is a flow chart showing details of the initial operation execution process of step a6 in FIG.
In step e1 of FIG. 36, the engine controller 131
In the memory area related to the state of communication with the outside of the device, data in a warm-up state is set as various parameter settings and characteristic settings immediately after the current power is turned on. In step e2, it is determined whether or not the initialization processing of the image controller 130 is completed and the communicable signal CPRDY from the image controller 130 indicating that the communication with the engine controller 131 is enabled has been established. After the establishment of the communicable signal CPRDY, the initialization process of the image controller 130 shown in FIG. 1 is completed and the command signal can be sent to the engine controller 131. It waits in the state where the status signal corresponding to the command signal can be output.

If the determination in step e2 is affirmative, the process proceeds to step e3 to perform a paper jam inspection operation, which will be described later, inside the LED printer 21. At step e4, the temperature instruction flag provided in the engine controller 131 is set to the data that is currently being heated. In step e5, the control-in-progress flag, which is controlling the temperature of the heating element 146 (see FIG. 11) of the fixing device 46, is set.
At step e6, the LED printer 21 makes the step e5.
Wait for 5 seconds in the operating state up to.

Thereafter, in step e7, it is judged whether or not the current operating state is the above-described preparation state of steps a1 to a6 shown in FIG. 27, and when the preparation state ends, the process moves to step e8. In step e8, it is determined whether the process cartridge 73 is mounted in the upper housing 23 shown in FIG. If it is installed, the process proceeds to step e9 to wait for installation of the waste toner box 99. Step e1
At 0, the motor 126 is started. Specifically, a flag is set in the CPU 145, which is an operation state in which the motor 126 changes the rotation speed in an increasing direction, and a control signal for driving the motor 126 is output in this operation state.

At step e11, it is waited until the rotation speed of the motor 126 becomes constant, and at step e12, the charger 8 is started.
Apply power to 1. That is, the photosensitive drum 77 is brought into a state where a white original image is formed. This is because the photosensitive drum 77 is activated at the time of the current processing, but the surface of the photosensitive drum 77 is at least partially uncharged, and the toner adheres when passing the developing roller 76, and this toner is The operating state of being scraped off by the cleaning device 80 continues. This wastes toner in vain. In this embodiment, useless adhesion of toner to the photosensitive drum 77 is prevented. In step e13, the timing for applying the bias voltage to the developing roller 76 is awaited. The application of the bias voltage is for charging the toner in the process cartridge 73 with static electricity having a predetermined polarity. When the application timing comes, in step e14, a bias voltage is applied to the developing roller 76.

In step e15, it is determined whether 10 seconds have passed since the application of the bias voltage, for example.
If 10 seconds have not elapsed, the paper jam inspection process similar to step e3 is performed in step e16, and step e17
Then, it is determined whether or not the toner supply operation is currently being performed. If the toner replenishing operation is being performed, the process returns to step e16, and the processes of steps e16 and e17 are repeated until the toner replenishing operation is completed. When it is determined in step e17 that the toner replenishing operation has ended, the process returns to step e15.

When the determination in step e15 is affirmative, the process proceeds to step e18, the application of power to the charger 81 is stopped, and after the application of power to the charger 81 is stopped in step e19,
After elapse of the specified time, application of the bias voltage to the developing roller 76 is stopped in step e20. At step e21, the motor 126 is stopped. Specifically, a flag corresponding to the control for changing the rotation speed of the motor 126 in the deceleration direction is set in the CPU 145, and the motor 126
Clears the flag indicating that is rotating at a constant speed. Thereafter, in step e22, a threshold value is set in the flag that defines the temperature of the fixing device 46. This threshold value is set to a predetermined standby temperature immediately after the power is turned on, and when printing is actually started in a state where the temperature is maintained at such a standby temperature, an operating temperature higher than the standby temperature, which will be described later, is set. Becomes the specified temperature and the temperature is raised.

(4f) Error Checking for Paper Jam etc. FIG. 37 is a flow chart for explaining the paper jam checking operation such as step e3 in FIG. In the LED printer 21 of the present embodiment, a part of the paper jam inspection operation described later is performed in the inspection operation when the registration roller 38 is stopped or the discharge rollers 58, 59; 64, 65 are stopped and the upper housing 23 shown in FIG. The processing operation associated with the opening operation is also used. In step f1 of FIG. 37, it is checked whether or not the sensor 39 shown in FIG. 2 detects the recording paper. If this judgment is negative, it is checked in step f2 whether or not the sensor 51 shown in FIG. 2 detects the recording paper. If this judgment is also negative, the process ends. If at least one of the determinations at steps f1 and f2 is affirmative, the process proceeds to step f3.

In step f3, as described above, the registration roller 38 and the respective discharge rollers 58, 59; 64, 65.
This is a process that is executed even when is stopped. In step f3, output initialization processing is performed. In the output initialization process, the motor 126 is stopped and the CPU 145 shown in FIG.
The general-purpose counters 215 and 216 are cleared to be in operation, and the toner replenishment flag in the status data, which is data corresponding to the operation state of the engine controller 131, is sent to the image controller 130.

Thereafter, in step f4, the stack pointer is initialized, and in step f5, the status data to the image controller 130 includes the request data for resending the print data corresponding to the page where the printing is interrupted and the paper jam occurrence data. And set. After that, in step f6, the process waits for the upper housing 23 to be opened. This post-processing moves to step f9 described later.

When the upper housing 23 is opened during the operation of the LED printer 21, the cover opening process is performed.
This cover opening process is a process after step f7 in FIG. 37, and in step f7, the same stopping process of the motor 126 as in step f3 is performed. In step f8, the stack pointer is initialized as in step f4. In step f9, the image controller 130
Set the cover open data to the status data to, while clearing the toner low flag. Step f1
At 0, the operation of closing the upper housing 23 is waited, and when closed, the process proceeds to step f11, and the cover open flag in the status data is released. In step f12, it is determined whether or not the sensor 39 detects the recording paper. If the determination is negative, step f13
Check whether or not the sensor 51 detects the recording paper. If this determination is also negative, the data resend request and the paper jam flag in the status data are cleared in step f14. After this, the process proceeds to step a6 in FIG.

As described above, in the present embodiment, the paper jam processing or the registration roller 38 and the paper discharge roller 5 are carried out.
8, 59; 64, 65 stop processing and the like, and further, cover opening processing accompanying opening of the upper housing 23
The range of programs that can be shared is shared.
Therefore, it is possible to eliminate the need to create an individual program including the contents common to each process, and it is possible to achieve both the time and effort required for creating the program and the reduction in the memory capacity for storing the program.

(4g) Standby Processing FIG. 38 is a flow chart showing the details of the standby processing in step a7 of FIG. In step g1, the motor 1
26 is in operation and the motor 126
Is operating, it is determined in step g2 whether the operation of the motor 126 is accelerating. If the determination is negative, it is determined in step g3 whether the motor 126 is decelerating. If this judgment is also negative, in step g4,
After the power supply to the LED printer 21 of the present embodiment is turned on, it is determined whether or not the standby state in which the upper housing 23 is opened, the paper jam processing is not performed, and the printing operation is not performed has taken 30 minutes as an example. If this decision is positive,
At step g5, the activation process of the motor 126 similar to that at step e10 in FIG. 36 is performed. After this, the process proceeds to step g6. If the determination in step g4 is negative,
Immediately move to step g6 without performing step g5.

That is, when the LED printer 21 is powered on and therefore the heating roller 49 of the fixing device 46 is heated to about the standby temperature, the printing operation is not performed and the fixing device 46 is left stationary for a long time. If fixed, the pressure roller 48 will be deformed, or the heat distribution in the circumferential direction of the pressure roller 48 will be greatly deviated, and the fixing process accompanying the printing operation will be insufficient. Therefore, in this embodiment, in such a standby state, when the stationary state of the fixing device 46 has passed for 30 minutes, the motor 126 is driven for a few seconds each time and the fixing device 46 is operated. This state is shown in the time chart of FIG.

That is, the print start signal PRNT changes from the image controller 130 to the engine controller 131.
39 is not input to the fixing device 46.
As shown in (2), the standby temperature is set in advance. In such a state, as shown in FIG. 39 (1), time T3 (for example, 10 to 30 minutes) elapses every time T3 elapses.
The motor 126 is driven for about 2 (for example, 1 to 2 seconds) to rotate the heating roller 49 and the pressure roller 48 of the fixing device 46. In this state, when the low-active print start signal PRNT is input from the image controller 130 to the engine controller 131, at that time, the fixing device 46 further moves from the predetermined standby temperature as shown in FIG. 39 (2). The temperature is raised to a predetermined operating temperature of high temperature. After this, the processing moves to the introduction processing of step a8 in FIG.

Referring again to FIG. 38, step g5
After the motor 126 is driven in step S6, it is determined in step g6 whether the print enable signal RDY, which is the output signal from the engine controller 131 shown in FIG. 1, is output. The print enable signal RDY is (1) valid in the engine controller 131 when the LED printer 21 is powered on, and invalidated when the power is cut off.
RDY is valid. (2) The temperature of the fixing device 46 in the engine controller 131 is within the specified range. (3) Process cartridge 7 in LED printer 21
3 is installed. (4) The waste toner box 99 is attached to the LED printer 21. (5) The paper cassette 29 containing the recording paper of the size specified by the image controller 130 is attached to the LED printer 21. (6) The LED printer 21 is not jammed. (7) The engine controller 131 does not output the print data resend request as described above. (8) The LED printer 21 is not performing the test print. (9) In the LED printer 21, the upper housing 2
3 is closed. (10) LED printer 21 is paused (PAUSE state)
is not. (11) The exhaust fan motor is rotating steadily. (12) The toner in the process cartridge 73 and the toner box 74 is not empty. (13) The current operating state of the LED printer 21 is shown in FIG.
The toner replenishment mode described with reference to FIG.

When all of these conditions are satisfied, the engine controller 131 validates the print enable signal RDY. If such a printable signal RDY is valid, the process proceeds to step g7 and the image controller 130
It is determined whether the print start signal PRNT output from is valid. The print start signal PRNT is a signal for the image controller 130 to instruct the engine controller 131 to start or continue the printing operation.
That is, when it is determined in step g7 that the print start signal PRNT is not valid, it is determined in step g8 whether the test print switch 212 shown in FIG. 1 is operated. If it is operated, the engine controller 131 sets the test printing data in the status data in step g9, and the image controller 130
To transmit. After that, the LED printer 21 performs test printing consisting of character and symbol strings in a preset order. If the print start signal PRNT is valid in step g7, the engine controller 131 receives print data from the image controller 130 and performs a print operation, as described later.

In step g6, the print enable signal RD
When Y is invalid, that is, not output, or when the test print switch 212 is not operated in step g8, the process returns to step g1 and the above-described process is repeated.

If the determination is affirmative in any of the steps g1, g2, g3, the process proceeds to step g10 and the paper jam processing described with reference to FIG. 37 is executed. After that, in step g11, the motor 126 is started as shown in FIG.
It is determined whether or not the time T2 shown in Fig. 36 has elapsed, and if it has elapsed, the stop process of the motor 126 similar to step e21 of Fig. 36 is performed in step g12, and the process is performed in step g6
Move on to. Even when the determination in step g11 is negative, the process moves to step g6.

(4h) Introduction Process FIG. 40 is a flow chart for explaining the details of the introduction process of step a8 in FIG. 27, and FIG. 41 is a time chart for explaining the operation of the LED printer 21 near the introduction process. As shown in FIGS. 39 and 41 (1), this introduction process is started from the time when the print start signal PRNT becomes valid during the standby process of FIG. In step h1 of FIG. 40, the temperature rising data is set in the temperature instruction flag in the status data STS transmitted to the image controller 130, and in step h2, the horizontal synchronizing signal B is set.
The output of D is started. In step h3, the general-purpose count operation flag is cleared, and the rotation end flag set during the previous printing operation is cleared.

In step h4, it is determined whether the motor 126 of the LED printer 21 is changing its speed in the speed-up or speed-down direction. If this determination is affirmative, the process proceeds to step h5, the paper jam process described with reference to FIG. 37 is executed, and the process returns to step h1.

If the determination in step h4 is negative, that is, if the motor 126 is rotating at a constant speed or is stopped, the process proceeds to step h6 to determine whether the motor 126 is rotating at a constant speed. To judge. If this judgment is negative, it means that the motor 126 is stopped, and the process moves to step h7 and step e in FIG.
The same motor starting process as 10 is performed, and then the process returns to step h1.

At step h6, the motor 126
Is rotating at a constant speed, the process proceeds to step h8, where the charger 81
It is determined whether or not it is time to apply the drive voltage to. This timing is set by the transmission timing of the print data DT transmitted from the image controller 130 in the circumferential direction of the photosensitive drum 77. If the determination in step h8 is affirmative, in step h9, the process shown in FIG.
As shown in 1 (4), the operating voltage is applied to the charger 81.

Next, at step h10, the developing roller 76
It is determined whether or not it is time to apply a bias voltage to. To apply the bias voltage to the developing roller 76, the charger 8 is applied on the photosensitive drum 77 in step h9.
The bias voltage is applied when the portion charged with 1 reaches the developing position facing the developing roller 76.
This is to suppress the adhesion of toner and carrier to the photosensitive drum 77 and the like to the minimum. When the determination in step h10 is affirmative, a bias voltage is applied in step h11 as shown in FIG. 41 (5). Step h12
Then, the previous rotation end flag is set, and step h1
At 3, it is determined whether or not the previous rotation end flag is set. That is, if the determination in step h8 is negative, the process reaches step h10 without processing step h9, and if the determination in step h10 is negative, the process proceeds to step h13 without processing steps h11 and h12. Because it changes.

If the determination at step h13 is affirmative, at step h14, as shown in FIG. 41 (6), the fixing device 4
From the standby temperature in the standby state, it is determined whether the temperature of 6 has reached an operating temperature higher than this. If it has not arrived, the paper jam processing described with reference to FIG. 37 is performed in step h15, and the processing is returned to step h8. If the determination in step h14 is affirmative, the process shifts from the introduction process shown in FIG. 40 to the printing process described later.

As described above, in the introduction process, as shown in FIG. 41, after the print start signal PRNT is input in the standby state, the speed of the motor 126 is increased and the driving power is applied to the charger 81. When the recording paper is supplied from the paper cassette 29 or the manual paper feeding device 83, a period for establishing a state in which the printing operation can be executed is established.

(4f) Printing Operation FIG. 42 is a flow chart for explaining the printing operation.
43 is a diagram showing a process associated with the movement of the recording paper in the LED printer 21 during the printing operation period, FIG. 44 is a timing chart for explaining the operation of each part in the printing operation state, and FIG. 45 is the printing operation state. 3 is a timing chart for explaining the operation of each unit in FIG. This printing operation state is, as shown in the transition diagram of FIG. 22 and the timing charts of FIGS. 44 and 45, the introduction operation state 1 described above.
A control signal for requesting the image controller 130 to output the first printing state 193 after the paper feed roller 30 is activated in 92 and a vertical synchronization signal VSY synchronized with the image data for one page in the first printing operation state 193. VSR
In the second printing state 194 after the output of Q from the engine controller 131 and in the period after the printing of the first recording sheet is completed, the next recording sheet can be fed. And the print standby state.

In step i1 of FIG. 42, details are shown in FIG.
The counter setting operation shown in FIG. That is,
At step j1 in FIG. 46, the internal operation flag of the CPU 46 is set, and the recording paper conveyance data is set as the status data to the image controller 130. Step j2
Then, whether the paper is fed from the paper feed cassette 29 shown in FIG. 2 or the recording paper is placed on the manual paper feed device 83 and the manual paper feed operation is performed. To judge.

When the recording paper is not placed on the manual paper feeding device 83 and therefore the paper feeding cassette 29 is used,
The process moves to step j3, the electromagnet 124 is energized to connect the clutch, and the power of the motor 126 is supplied to the paper feed roller 30.
Supply to. In step j4, when the recording paper fed by the cassette is fed in the LED printer 21, the sensor 39, the registration roller 38, the transfer discharger 100, the fixing device 46, the sensor 54, and the ejection rollers 58, 59 from the start of the feeding. RO, shown in FIG. 1, is the pre-measured time data required to pass 64 and 65 respectively.
Specify the address to read from M133. At step j5, the size of the used paper feed cassette 29 is read from the size sensor 213 that optically detects the size of the paper feed cassette 29 provided in the lower housing 22. After this, the process proceeds to step j10.

If it is determined in step j2 that the sensor 87 detects the recording paper and the manual paper feed mode is selected, the process proceeds to step j7.
The electromagnetic plunger 125 is energized to transmit the power of the motor 126 to the transport roller 86. At step j8, the recording paper is detected by the sensor 39, from the paper feeding start time in the case of manual paper feeding.
Registration roller 38, transfer discharger 100, fixing device 4
6, sensor 54 and discharge rollers 58, 59; 64, 6
The address for reading the pre-measured time data passing through each of 5 from the ROM 133 shown in FIG. 1 is designated.

At step j9, the manual paper feed device 83 is not provided with a sensor for detecting the size of the recording paper, and therefore the CPU 146 designates that the size of the recording paper is undecided. In step j10, it is judged whether or not the general-purpose counter 215 shown in FIG. 1 is in operation. If it is in operation, in step j6 the image controller 13
Data for which the general-purpose counter 215 is operating is set to the status data to 0, and the general-purpose counter 216 is cleared. Further, the size data of the recording paper detected in steps j5 and j9 is stored in a memory such as a RAM.

If the judgment at step j10 is negative, at step j11 the operating data of the general-purpose counter 216 is set as the status data to the image controller 130, the general-purpose counter 215 is cleared, and step j
The size data of the recording paper read at 5 and j9 is recorded.

At step i2 in FIG. 42, 1 m which will be described later.
s Wait for completion of interrupt processing. When the 1 ms interrupt process ends, the process moves to step i3. At steps i3 and i4, various setting operations for the first general-purpose counter 215 and the second general-purpose counter 216 shown in FIG. 1 are performed as shown in the flowcharts of FIGS. 47 and 48.

In step k1 of FIG. 47, the general-purpose counter 2
It is determined whether or not 15 is in operation, and if not in operation, the process ends. If in operation, in step k2, a plurality of fixed counts corresponding to the processes corresponding to the count values of the general-purpose counters 215 and 216 are performed. Data is read from the event table in which the value and the start address of the corresponding processing program are stored, and it is determined whether or not the data read in step k3 matches the count value of the general-purpose counter 215. Thereafter, in step k4, the processing destination address is read from the event table, and the general-purpose counter 2
A flag indicating the processing of 15 is set.

[0153]

[Table 1]

When the process of step i2 in FIG. 42, that is, the process for the first recording sheet is completed, the process for the second recording sheet is performed as step i4. Specifically, it is shown in FIG. Figure 48 Step m
In step 1, it is determined whether the general-purpose counter 216 for the second recording sheet in the LED printer 21 is operating. If it is not in operation, the process ends, and if it is in operation, the event table data is read in step m2. In step m3, it is determined whether the read count data of the event table matches the count data of the general-purpose counter 216. If they do not match, the process ends, and if they match, the address in which the program of the corresponding process is stored is read from the event table in step m4.
Data is set in a flag indicating the start of processing by the second general-purpose counter 216, and the image controller 130 is set.
To transmit. After this, the processing moves to the processing destination address read in step m4.

An example of the processing contents in FIGS. 47 and 48 is the output operation of the control signal VSRQ transmitted from the image controller 130 to the engine controller 131. The processing content is shown in the flowchart of FIG. At step n1, the general-purpose counters 215 and 216 are cleared. In step n2, the general-purpose counters 215 and 21 are used for the subsequent processing.
It is determined which one of 6 will be used. When the counter 215 is used, the general-purpose counter 21 is operated at step n3.
Image controller 130
Write status data to. After this, the process proceeds to step n5.

When the general-purpose counter 216 is used in step n2, the instruction data for using the general-purpose counter 216 is set in the status data in step n4, and data transmission with the image controller 130 is performed. In step n5, it is determined whether the operation state of the LED printer 21 is test printing, and if it is not test printing,
At step n5, the control signal VSRQ for requesting the vertical synchronizing signal VSY to the image controller 130 is output.

If the determination in step n5 is affirmative, the general-purpose counter 21 is added to the status data in step n6.
Which of 5, 216 is used to determine which instruction is set is determined. When the general-purpose counter 215 is set, the general-purpose counter 215 is cleared in step n8, and the control table corresponding to the size of the recording paper is selected in step n9. In step n10, as an example, an area that is an effective printing range when printing one line is set. After this, the process ends. If the instruction to use the general-purpose counter 216 is set in step n7, the general-purpose counter 216 is cleared in step n11.
At step n12, the control table corresponding to the size of the recording paper is selected. After this, the process proceeds to step n10.

The entire printing process will be described with reference to FIGS. 42 to 45. In step i1 of FIG. 42, the maximum number of recording sheets that are present in the LED printer 21 at the same time mechanically, that is, two sheets, is dealt with, and in order to perform a process associated with the movement in the LED printer 21 for each recording sheet. The counter initialization operation set for each recording sheet is performed. At this step i1, the electromagnet 124 shown in FIG.
At time t6, the first recording sheet is taken out from the paper feed cassette 29. In steps i3 and i4, 2 as described later.
Two general-purpose counters 215, 21 corresponding to one recording sheet
The processing content to be executed is recognized corresponding to the count value of 6, and after the processing content is executed, the operation described in detail later is performed. In step i5, as will be described later, processing relating to the timing at which the control signal VSY generated from the image controller 130 for each recording sheet is input to the engine controller 131 is performed.

At step i6, it is judged whether or not the general-purpose counter 215 corresponding to the first recording sheet in the LED printer 21 is in operation, and at step i7, the general-purpose counter corresponding to the second recording sheet. Determine if 216 is in operation. That is, in steps i6 and i7, it is determined whether or not one or two recording sheets are moving in the LED printer 21. If all of these judgments are negative, it is judged in step i8 whether or not the process cartridge 73 is in the toner supply operation state. If this judgment is also negative, the power supply to the charger 81 is cut off in step i9.

If any of the determinations at steps i6 to i8 is affirmative, the process proceeds to step i10 to determine whether a test printing operation is in progress. If the test printing operation is in progress, whether or not the recording paper can be supplied from the paper feeding cassette 29 in step i11, that is, the paper feeding cassette 29 is mounted in the lower housing 22, and the recording paper remains in the paper feeding cassette 29. Judge whether or not it is in the state. If this judgment is affirmative, step i1
At 2, it is determined whether the test switch 212 shown in FIG. 1 is in the ON state. If it is not ON, the process returns to step i1 and the setting operation is performed in either or both of steps i2 and i3. When the determination in step i11 is negative and the determination in step i12 is affirmative, the process returns to step i2. Step i1
If the determination of 2 is negative, the process returns to step i1.

If the determination in step i10 is negative, the process proceeds to step i13 to perform an output process regarding the print enable signal RDY. In step i14, it is determined whether the next recording sheet can be fed, and if it is possible, the print start signal P
It is determined whether the RNT is established, and if affirmative, the process proceeds to step i. If the determinations at steps i14 and i15 are negative, the process proceeds to step i2.

That is, the above-mentioned steps i1 to i8,
The process of i10 to i15 is 1 by the process of step i2.
It will be executed every ms. Therefore, as will be described later, the processing of steps i3 and i4 is also performed every 1 ms.

If the determination in step i8 is negative, the power supply to the charger 81 is cut off in step i9, and then in step i16, it waits until a predetermined time elapses from the cutoff of the charger 81. The application of the bias voltage to the developing roller 76, which will be described in detail later, is stopped at i17. In step i18, it is determined whether or not the LED printer 21 is currently performing test printing, and if affirmative, it is determined in step i19 whether the test switch 212 shown in FIG. 1 is in the ON state. If this judgment is affirmative, it is judged in step i20 whether or not the recording paper remains in the paper feeding cassette 29 or the manual paper feeding device 83. If this determination is affirmative, the process proceeds to step i21, in which the charging device 81 is driven as described later in detail, and printing is continued. Then, the process returns to step i1.

If the determination in step i18 is negative, the process proceeds to step i22 to determine whether or not the print start PRNT is established. If the determination is affirmative, the print enable signal RDY becomes valid in step i23. Determine whether or not If this determination is affirmative, step i24
In step i21, as in step i21, the charging device 81 is driven to continue printing, and the process returns to step i1.
If the determinations at steps i22 and i23 are negative, the process proceeds to step i25, and the image controller 13
In the status data to 0, the status data which is under test printing is canceled. At step i26, FIG.
The stopping process of the motor 126 similar to that in step e21 of 6 is performed, the stopping process of the horizontal synchronizing signal BD is performed in step i27, and the process of setting the standby temperature of about 100 ° C. in the fixing device 46 is performed in step i28. Done.

That is, in the present embodiment, the recording paper is taken into the LED printer 21 from the paper feed cassette 29 or is supplied from the manual paper feed device 83 until the printing operation is completed and the paper is ejected to the outside. , Step i of FIG.
The processes 1 to i8 and i10 to i15 are cyclically performed. That is, at time t6 in FIG. 43, the electromagnet 124 shown in FIG. 1 is energized, the clutch is engaged, and the paper feed roller 30 is rotationally driven. This rotation drive is shown in Figure 44 (1).
As shown in FIG. 3, the number of rotations is, for example, two, and the leading end of the recording paper in the paper feed cassette 29 is in contact with the registration roller 38 via the paper feed roller 30 and the transport roller 37, and is in a curved state.

Sensor 3 at time t7 in FIGS. 43 and 44.
When 9 detects the recording paper, the engine controller 131 sends a vertical synchronization signal V to the image controller 130 at time t8 of a predetermined timing as described later.
The control signal VSRQ requesting the generation of SY is shown in FIG. 44 (3).
Output as shown in. Correspondingly, at time t9, the vertical synchronization signal VS is output from the image controller 130.
When Y is input as shown in FIG. 44 (4), the registration roller 38 is activated at time t10 as shown in FIG. 44 (5).

After the registration roller 38 is activated as shown in FIG. 44 (5), the transfer device 100 is energized at time t11 as shown in FIG. 45 (5) to transfer the toner image on the photosensitive drum 77. Be seen. After that, as shown in FIG. 45 (6), when the sensor 51 detects the recording paper at the time t12, the printing standby state in which the next recording paper can be fed is entered. Sensor 5
1 detects the trailing edge of the recording paper at time t13, and when a predetermined time has passed, it means that the discharging of the recording paper is completed, and thereafter, the recording paper is stopped.

Details of the processing in step i5 of FIG. 42 will be described below.

In FIG. 50, step o1, the control signal V
It is determined whether the SRQ is output, and if it is output, it is determined whether the vertical synchronization signal VSY from the image controller 130 is established. If this judgment is affirmative, as shown in FIG. 44 and FIG.
Since at least one sheet of recording paper exists in the D printer 21, the number of retained sheets in the machine is incremented by +1 in step o3, and the control signal VSRQ output from the engine controller 131 is released in step o4. After this, the processing moves to step n7 in FIG. If either of the determinations at steps o1 and o2 is negative, the process returns to step i6 in FIG.

That is, in the process of FIG. 42, after the general-purpose counters 215 and 216 are started in step i1 in accordance with the recording paper being taken into the LED printer 21, the general-purpose counters 215 and 216 are activated in steps i3 and i4 every 1 ms. The number of repetitions is counted as a count value, and if the same count value as the count value associated with the various processing contents shown in Table 1 is reached, the processing contents are executed. . By repeating this process, the paper feed roller (electromagnet 124) 30 is turned off, the size sensor 213 is turned on, the control signal VSRQ is output, and the plunger 1 is turned on.
25, the registration roller 38 on, the test data on, the transfer discharger 100 on, the control flag PRQ on, the sensor 51 on, the test data off, the size sensor 213 off, the registration roller 38 off, The transfer discharger 100 is turned off, the sensor 51 is turned off, and the motor 1 is turned off.
Each processing such as turning off 26 is performed.

FIG. 51 shows steps i21 and i24 of FIG.
6 is a flowchart showing details of the print continuation process of FIG. In step p1, the general-purpose counters 215 and 216 are cleared, and in step p2, the temperature of the fixing device 46 is instructed. In step p3, the engine controller 131 performs a process of generating the horizontal synchronization signal BD, and in step p4
Then, it is determined whether or not it is time to energize the charger 81. At the energization timing, the charger 81 is energized in step p5.

At step p6, it is judged whether or not it is the timing to apply the bias voltage to the developing roller 76. If this judgment is affirmative, a bias voltage is applied to the developing roller 76 in step p7, and step p8
Then, the completion of warming up of the fixing device 46 is awaited.
If the determination in step p4 is negative, step p5
Is not performed, and the process proceeds to step p6. In step p6, the processes of steps p4 to p6 are repeated until the timing of applying the bias voltage to the developing roller 76 arrives.

The above-described print continuation processing shown in FIG. 51 is executed in both steps i21 and i24 in FIG. Step i21 is a process executed as a test print, and step i24 is a process executed as a print process based on normal print data.

52 to 56 are timing charts showing the mutual relationship of various signals used in the LED printer 21 of this embodiment. 52 and 53 show the states of signals before and after the start of the printing operation and after the start of the printing operation. FIG. 52 shows the slowest continuous printing mode in FIG. 22, and FIG. 53 shows that printing is performed for each recording sheet. This is the operation mode to end. In FIG. 52, as shown in FIG. 52 (3), the charger 81 is stopped at the start time t14 of the second stop period, but the low-active print start signal PRNT is time t15, and the image controller 130 causes the engine controller 1 to stop.
When the data is input to 31, the charging device 81 is energized again to restart printing.

On the other hand, the example of FIG. 53 is the same as the example of FIG. 52 until the electric power to the charger 81 is cut off at the start timing of the second stop period. In FIG. 53, the print start signal PRNT is not input during the second stop period,
At 16, the application of the bias voltage to the developing roller 76 is stopped, the motor 126 is subsequently stopped, and the fixing device 46 is also set to the standby temperature and its operation is stopped.

FIG. 54 shows the print enable signal RDY and the control signal V
7 is a time chart showing a relationship with SRQ, VSY, and the like. In FIG. 54 (1), after the control signal RDY becomes low level and becomes valid, the print start signal PRNT becomes time t17.
Then, the control signal RDY becomes high level and becomes invalid. After the time t17, after the time T2 required for raising the temperature of the fixing device 46 from the standby temperature of about 100 ° C. in the above example to the operating temperature of about 150 ° C. to 160 ° C., for example, the control signal RDY becomes It becomes effective. After this, after the time T3 (5.5 seconds as an example) has elapsed from the time t18 when the print start signal PRNT becomes valid again, the engine controller 131 outputs the control signal VSRQ to the image controller 13 as shown in FIG. 54 (3).
0, and in response to this, the image controller 13
0 makes the vertical synchronization signal VSY low level at time t19, and at the same time, the data VD corresponding to the print contents for one page is shown in FIG. 54 (5) during the invalid period of the vertical synchronization signal VSY generated in time series. ) Is entered.

FIG. 55 is a time chart showing the relationship between the control signal VSRQ and the vertical synchronizing signal VSY. Figure 5
5 (1), the low-active print start signal P
In the state where RNT is at the low level, as shown in FIG. 55 (2), the engine controller 131 outputs the control signal VSRQ to the image controller 130 at time t20. The image controller 130 sets the vertical synchronization signal VSY to the valid period T at time t21 as shown in FIG. 55 (3).
4 (10 to 400 ms as an example)
As shown in FIG. 55 (4), the print data VD is set at time t21.
Is output from time t22 after a lapse of time T5 (for example, 300 ms or more) from. On the other hand, as shown in FIG. 55 (5), the image controller 130 generates the horizontal synchronization signal BD for each horizontal synchronization period associated with the printing operation.

FIG. 56 is a time chart showing the relationship between the horizontal synchronizing signal BD and the print data VD. FIG. 56
As shown in (1), the period T6 (for example, 2116 μ
Second), the low-active horizontal sync signal BD becomes
Since it became effective at time T7 (89 to 196.4μ)
(2,)
As shown in, the print data VD corresponding to one line in the printing operation is input from the image controller 130 to the engine controller 131. The horizontal synchronization signal BD becomes valid again after a lapse of a predetermined time after the input of the print data VD for one line from the image controller 130 to the engine controller 131.

(4j) 1 msec Interruption Process FIG. 57 is a flow chart for explaining the operation of the LED printer 21 of this embodiment. FIG. 57 referred to in the following description.
66 to 70, the engine controller 13 shown in FIG. 1 is executed when the main program of the LED printer 21 described with reference to the drawings is executed.
This is a process executed by interrupting the engine controller 131 every 1 ms by the count of the timer 132 of 1. That is, the flow charts in the above figures are 1 ms.
It is executed every time.

In the LED printer 21 of this embodiment, as described above, a maximum of two sheets of recording paper can be conveyed in parallel at the same time inside the machine body. The processing of such a maximum of two recording sheets in the body is performed by the first general-purpose counter 215 shown in FIG.
It is managed by the count value of the second general-purpose counter 216. On the other hand, in the LED printer 21, the fixing device 46
A large number of counters are required for the temperature control of the above and the toner replenishing operation in the process cartridge 73. If such a large number of counters are prepared by hardware, the circuit configuration becomes complicated, and if they are prepared as independent counters by software, the capacity on the memory for performing such counting operation becomes enormous and the LED printer 21 becomes It is difficult to use the provided memory efficiently.

Therefore, in this embodiment, the independent counters are set to the timer 132 except the general-purpose counters 215 and 216, and the step of counting the number of executions is set in the program executed every 1ms as described above. To do. That is, the count value of this counting step achieves the same function as a timer or a counter that performs a time counting operation every 1 ms.

That is, in the present embodiment, since the counting step performs the time counting operation every 1 ms, the time counting operation is performed by hardware or software based on the clock signal of the extremely high frequency from the oscillation circuit 228 shown in FIG. When this is done, the problem that the configuration is enlarged or the effective use of the memory is hindered is solved.

FIG. 57 shows the LED printer 2 as described above.
It is a flowchart of the process performed by setting an interrupt every 1 ms for one main processing program. In step q1, the reading process for the gate array 134 of the CPU 145 described with reference to FIG. 11 is performed. That is, the various sensors 33, 39, 51, 87 shown in FIG.
The output such as is read. In step q2, the flag F used in the majority decision process executed as described later is set to

[0184]

[Equation 1]

The calculation is performed as follows.

At step q3, the conductive / interrupted states of the cover switch 217 and the cassette switch 218 shown in FIG. 1 are read. At step q4, the result of the majority decision is stored as a flag F. At step q5, the count value is +
Increment by 1. That is, this step q5
However, as mentioned above, the flow chart of FIG.
It is a time counting step in 1 ms units that counts up each time it is executed.

At steps q6, q7 and q8, it is judged whether or not the instruction value of the counter of 1 msec at step q5 is 1000 as an example, and if negative, the counter instruction value of the corresponding counting step is 100 * at step q7. n (n
Is a natural number), and if negative, the instruction value of the counter in step q5 is 10 * n in step q8.
To determine if. If this determination is negative, the process proceeds to step q12, and the heating element 14 of the fixing device 46 is
It is determined whether or not the temperature control regarding 6 is being performed. If the determination in step q6 is affirmative, the process moves to step q9, in which the 1 second counter set in the memory is set to 0, and +1 is incremented in the next process. In step q10, the same 0.1 second counter is incremented by +1. In step q11, the 0.01 second counter is incremented by +.
Increment by 1. After this, the processing is step q12.
Move on to. If the determinations at steps q7 and q8 are positive, the process proceeds to steps q10 and q11, respectively.

If the judgment in step q12 is affirmative, the temperature signal from the thermistor 147 which detects the temperature of the heating element 146 of the fixing device 46 is fetched in step q13 to start the analog / digital conversion processing. After this, the process proceeds to step q15. When the determination in step q12 is negative and the heating element 146 is in the constant temperature state, the process proceeds to step q14.

At step q14, the engine controller 131 sets, in the status data to the image controller 130, data that the heating element 146 is in a low temperature state, and stops the supply of drive power to the heating element 146,
After this, the process proceeds to step q15.

Although the processing in steps q1 to q14 is temperature control of the heating element 146, step q15
Subsequent processing is an operation related to toner replenishment in the process cartridge 73.

(6) Toner Replenishing Process In step q15, it is determined whether the motor 126 is rotating. If it is rotating, the engine controller 131 determines in step q16 whether the toner reduction data has been set in the status data to the image controller 130. If not set, the toner density is detected by the toner sensor 104 in step q16. In step q17, it is determined whether or not the sampling timing (for example, 0.35 second interval) has been reached. If it has reached, in step q18, it is determined whether the output of the toner sensor 104 is at a low level, that is, the toner concentration near the agitator 78 of the process cartridge 73 has decreased.

When the amount of toner in the process cartridge 73 decreases and the determination in step q18 becomes affirmative,
In step q19, the engine controller 131 sets instruction data for driving the toner motor 214 in the gate array 134, and drives the toner motor 214. In step q20, it is determined whether the toner supply from the toner box 74 has continued for 20 seconds. This toner replenishment for 20 seconds is the toner replenishment operation 20 of FIG.
It is 3. If the determination in step q20 is affirmative, 20
Despite the toner supply for 2 seconds, the toner sensor 104
Means that the toner density in the process cartridge 73 is low, and the replenishment mode is instructed in step q21. That is, the toner supply operation 204 of FIG. 24 is performed.

In this replenishing operation state, the motor 126 is stopped and the operation of the LED printer 21 is totally stopped, and only the toner motor 214 is driven to replenish the toner. In step q22, it is determined whether the toner replenishing operation in such a state has continued for 2 minutes as an example. If the determination in step q22 is affirmative, it means that the toner sensor 104 is still detecting that the toner concentration is low, even though the toner is replenished in the above-described state. The controller 131 sets the toner reduction data in the status data for the image controller 130. That is, the operation moves to the toner-free operation 205 in FIG. As a result, the display unit 129 of the LED printer 21 shown in FIG. 1 displays either the toner out of the toner box 74 or the state in which the toner box 74 is not attached to the process cartridge 73. Thereafter, in step q24, the toner motor 214 is stopped, and in step q25, it is detected whether or not the upper housing 23 is in the open state.

When it is determined in step q15 that the motor 126 is stopped, or in step q16, the engine controller 131 causes the image controller 1 to stop.
If the toner reduction data has already been set in the status data for 30, the process immediately moves to step q24 to stop the toner motor 214. Step q1
When the determination result in No. 8 is negative and the toner sensor 104 detects that the toner concentration in the process cartridge 73 is relatively high, it is determined in step q26 whether the toner replenishing operation as described above has continued for at least 2 seconds. If this judgment is negative, the routine proceeds to step q19, and the above-described processing is repeated to continue the toner supply.

If the determination in step q26 is affirmative, the process moves to step q27 and the instruction to drive the toner motor 214 is cleared. After this, the process proceeds to step q28.
On the other hand, if both of the judgment processes of the steps q20 and q22 are negative, both processes are the same as the step q28.
Move on to. In step q28, steps q19 and q27
The toner motor 214 is driven or stopped in response to the toner motor drive instruction set or cleared in (1).

After the processing of steps q24 and q28 is completed, step q25 is executed and the LED printer 2
It is determined whether or not the cover 219 shown in FIG. 2, that is, the upper housing 23 is open. If it is in the open state, in step q29, it is determined whether or not the status data from the engine controller 131 to the image controller 130 has already been set with the data corresponding to the cover open. If it has not been set, the cover opening inspection process after step f7 in FIG. 37 is performed. On the other hand, if the determination in step q29 is affirmative, in step q30, the engine controller 131 causes the image controller 13 based on the key operation of the operator.
It is determined whether or not a Pause command from 0 is received. If this determination is affirmative, the paused state of the LED printer 21 is checked.

If the determination in step q30 is negative, the state of the communication enable signal CPRDY transmitted from the image controller 130 is confirmed in step q31. The communicable signal CPRDY is transmitted to the image controller 130.
Is a signal indicating that the initialization process of the image controller 130 is completed after the power is supplied to the engine controller 130 and the command signal and the data signal can be transmitted and received to and from the engine controller 131. After this, step q
At 32, whether the waste toner box 99 shown in FIG. 5 is attached to the process cartridge 73 is inspected as described later. The processing relating to steps q29 and q30 will be described in detail below. If the determination in step q29 is negative, the cover open check process of FIG. 37 is executed, and then the initial operation execution step of step a6 shown in FIG. 27 is performed. If the determination at step q30 is affirmative,
Perform pause processing. This pause process is shown in FIG. 37, step f.
After the output initialization process of 7, the engine controller 13
1 executes an operation of driving the motor 126 or the toner motor 214 of the LED printer 21 or waits in a pause state. However, since the program shown in FIG. 57 is executed every 1 msec, this pause process is performed again from step q1 at the time of the next 1 msec interrupt, and as described above as long as the pause command is received. Pause processing is performed.

That is, in the LED printer 21,
The engine controller 131 continuously performs the 1 msec interrupt process shown in FIG. 57, stops the driving mechanism such as the motor 126 and the toner motor 214, and also stops the operation of the electrical mechanism such as the fixing device 46 and the charger 81. Maintain the condition. The cancellation of such a paused state is based on a key operation by the operator or the like.
Is output by outputting a pause state release command to the engine controller 131.

When the engine controller 131 receives the pause state cancel command as described above, the above-mentioned step q30
Is negative, and the process of confirming the state of the communicable signal CPRDY described above is performed in step q31. The communicable signal CPRDY is in a state in which after the power is supplied to the image controller 130, the initialization processing of the image controller 130 is completed and the command signal and the status signal can be transmitted / received to / from the engine controller 131. It is a signal indicating that

In step q32, the presence or absence of the waste toner box 99 shown in FIGS. 4 and 5 is determined by reading the state of the detection switch 110 shown in FIG.
Whether or not the process cartridge 73 is mounted is detected by the cartridge sensor 230 of the holding member 66 of the process cartridge 73 shown in FIG.

At step q33, it is judged whether or not the paper feed cassette 29 shown in FIG. 2 is attached by whether or not a signal relating to the size of the recording paper is output from the size sensor 213. The presence or absence of recording paper in the paper feed cassette 29 is detected by the sensor 33, and the presence or absence of recording paper in the manual paper feed device 83 is detected by the sensor 87. At step q34, the LED printer 2
In No. 1, an unrecoverable error occurs depending on the processing of the user, and processing for confirming whether or not there is a call service request requiring repair inspection work by a repair staff is performed. In step q35, it is confirmed whether or not the LED printer 21 can operate normally, and step q3
At 6, the count values of various timers are updated and incremented, for example, by +1.

(7) Checking Waste Toner Box 99 and Process Cartridge 73 FIG. 58 is a flow chart showing details of the processing in step q32 in FIG. In step r1 of FIG. 58, the presence or absence of the waste toner box 99 shown in FIGS. 4 and 5 is determined by reading the state of the detection switch 110. If the waste toner box 99 is not attached, in step r2, The engine controller 131 sets the status data transmitted to the image controller 130 to the data in which the process cartridge 73 is not mounted, and the process returns to the process of FIG.

When the determination in step r1 is affirmative and the mounting of the waste toner box 99 is confirmed, it is determined in step r3 whether or not the process cartridge 73 is mounted.
If it is not attached, the process proceeds to step r2 and the above-mentioned processing is performed. If it is attached, in step r4, the status data transmitted to the image controller 130 by the engine controller 131 cancels the data not attached to the process cartridge 73, and the process returns to the process of FIG.

(8) Checking recording paper FIG. 59 is a flow chart showing details of step q33 in FIG. In step s1 of FIG. 59, it is determined whether the paper feed mode of the LED printer 21 is the cassette paper feed mode. This judgment is made by the engine controller 1
31 has set the cassette paper feed mode flag,
Alternatively, it is achieved by reading whether it is resetting. If the cassette paper feed mode flag is reset, it is determined in step s2 whether or not the sensor 87 of the manual paper feed device 83 detects the recording paper. If this determination is negative, in step s3, the engine controller 131 sets the paper-out data to the status data transmitted to the image controller 130, and the process returns to the program of FIG.

If the determination in step s2 is affirmative, in step s4 the no-paper data in the status data to the image controller 130 is canceled. If the determination in step s1 is affirmative, in step s5, corresponding data is set in the status data transmitted to the image controller 130 based on the cassette size data read from the size sensor 213.

Thereafter, in step s6, the size sensor 2
It is determined whether or not any signal is input from 13, and it is determined whether or not the paper feed cassette 29 is attached. If this determination is affirmative, it is determined in step s7 by reading the output from the sensor 33 whether or not there is a recording sheet in the attached sheet cassette 29. If the determinations at steps s6 and s7 are negative, the process returns to step s3 in either case. On the other hand, if the determination in step s7 is affirmative, the process proceeds to step s4 and the above process is repeated.

(9) Call Service Check FIG. 60 is a flow chart showing details of the process in step q34 of FIG. At step t1 in FIG.
It is determined whether a failure error has occurred in the D printer 21. If this judgment is affirmative, at step t2, the call service data for calling the repairing specialist is set in the status data transmitted to the image controller 130, and the process returns to the program of FIG. If the determination in step t1 is negative, it is determined in step t3 whether an operator service request has occurred. If this determination is affirmative, in step t4, call service data is set in the transmission data to the image controller 130 as in step t2, and the process returns to the program of FIG. If the determination in step t3 is negative, step t5
57, the call service data in the transmission data to the image controller 130 is released, and the program returns to the program of FIG.

(10) Normal Operation Check FIG. 61 is a flowchart showing details of the process in step q35 of FIG. In step u1 of FIG. 61, LE
It is determined whether or not the current operating state of the D-printer 21 is an obstacle to the normal operation. If this determination is negative, in step u2, the initialization completion signal PP described above is sent.
Determine if RDY is valid. That is, if the initialization completion signal PPRDY is a low active signal,
It is determined whether the signal is low level. If this determination is affirmative, in step u3, the initialization completion signal PP
For example, RDY is set to a low level to make it an effective output state, and the program returns to the program of FIG.

If step u1 is affirmative or step u2 is negative, that is, the LED printer 21
Is in a state where it is difficult to perform normal operation,
When the initial process of the engine controller 131 is not completed, the image controller 130
When it is not possible to send and receive the command signal and the status signal between the and the like, the process proceeds to step u4, and the initialization completion signal PPRDY is set to the invalid state and transmitted to the image controller 130. After this, the process returns to the program of FIG.

(11) Temperature Management FIG. 62 is a flow chart showing an example of the operation of controlling the temperature of the heating element 146 of the fixing device 46. This operation is also performed every 1 msec based on the timing operation of the timer 132 shown in FIG. Figure 2
It is executed as an interrupt process for the main process shown in FIG. Further, as described with reference to FIGS. 11 and 12, in the LED printer 21 of the present embodiment, when the temperature of the heating element 146 of the fixing device 46 is managed, first, the CPU 1
The control by the CPU 45 is the basic, and the CPU 145 in FIG.
1. The watchdog timer circuit 151 described with reference to FIG.
When reset is impossible even by the runaway prevention operation by
In order to prevent the occurrence of fire or smoke due to the excessive temperature rise of the heating element 146, it is compulsorily performed as an electric circuit like C
The PU 145 is reset and the power supply to the heating element 146 is cut off. Therefore, the processing operation shown in FIG. 62 is an operation when the CPU 145 is controllable.

In the following description, FIG. 11 and FIG. 12 will be referred to together. In step v1 of FIG. 62, it is determined whether the fixing device 46 is in an abnormal state. This judgment is 1m
As the processing result of FIG. 62 which is performed every second, it is performed based on the determination result of the abnormality / normality of the fixing device 46 at the previous execution time, which will be described later. If this judgment is affirmative, in step v2, the CPU 145 cuts off the transistor 154 under the control of the gate array 134, and the triac 1
By cutting off 56, the supply of the driving power to the heating element 146 is stopped. After this, the processing moves to the operation program of FIG.

If the determination in step v1 is negative, the CPU 145 reads digital data obtained by converting the temperature signal from the thermistor 147 by the analog / digital converter 150 in step v3. In step v4, a temperature range confirmation process of the heating element 146, which will be described later with reference to FIG. 63, is performed. In step v5, it is determined whether the thermistor 147 is under inspection. If it is under inspection, the engine controller 131 sets the image controller 1 in step v6.
Data indicating that the fixing device 46 is warming up is set to the status data transmitted to 30, and the process returns to the process of FIG. 57 as a semi-abnormal condition.

If the determination in step v5 is negative, the process proceeds to step v7, and the fixing device 46 described later with reference to FIG.
Selection and setting processing of the two types of temperature management operation modes regarding the heating element 146 are realized. In step v8, the operation mode relating to the temperature control set in step v7 is the table mode described with reference to FIG. 25, or the threshold mode for holding a constant temperature such as the standby temperature or the operating temperature described above. Check which one. If the determination in step v8 is the table mode, in step v9, warm-up data indicating that the heating element 146 is heating is set in the status data transmitted to the image controller 130 by the engine controller 131.

At step v10, the corresponding energization duty data Dd in the duty table 163 shown in FIG. 12 is read out based on the temperature data obtained from the thermistor 147. Further, the read energization duty data Dd is converted into the count value of the 1 ms counter which is incremented every 1 ms shown in step q5 of FIG. In step v11, the energization value which is the count value of the 1 msec counter corresponding to the energization duty data Dd obtained in step v10 is compared with the current count value of the 1 msec counter, and the current count value is the energization value. Is greater than.

That is, in step v10, the processing of FIG. 62 is performed the number of times corresponding to the energization value obtained by converting the energization duty data Dd read from the duty table 163 of FIG. 12 as the count value of the 1 msec counter. It will be judged whether it has been repeated.

If the determination in step v11 is negative, the processing of FIG. 62 has not been repeated until the energization value is reached, and the process moves to step v12, in which the CPU 145 shown in FIG. Is controlled to turn on the transistor 154 and turn on / off the triac 156 at a predetermined duty to heat the fixing device 46. After this, the process proceeds to step v14. If the determination in step v11 is affirmative, it means that the processing of FIG. 62 has been executed more than the number of times corresponding to the energization value, and the driving period of the heating element 146 at the predetermined duty has ended. At this time, the process moves to step v13,
The CPU 145 controls the gate array 134 to shut off the triac 156 and stop the supply of drive power to the heating element 146. After this, the process proceeds to step v14.

At step v14, it is judged whether or not the heating element 146 is under overheat inspection, which is an inspection for whether or not the heating element 146 is overheated, which is a dangerous temperature such as 210 ° C. which exceeds the safety limit. If this determination is negative, in step v15, the engine controller 131 sets the overheat inspection flag and sets the time required for the inspection to, for example, 1 minute, after which it is determined that the temperature of the heating element 146 is normal. It returns to the process of FIG. When the process of FIG. 62 is performed a plurality of times while the overheat inspection is being executed, the determination in step v14 is affirmative, and it is determined in step v16 whether one minute of the inspection time has elapsed. . If it has not elapsed, the heating element 146 is returned to the processing of FIG. 57 as a normal state, and the above processing is repeated. If the determination in step v16 is affirmative, error processing of the fixing device 46, which will be described later with reference to FIG. 66, is performed.

At step v8, if the current temperature control state of the fixing device 46 is the threshold mode described above,
The process proceeds to step v17, the above-mentioned overheat inspection flag is released, and the data being warmed up is released from the data transmitted from the engine controller 131 to the image controller 130. In step v18,
The heating element 1 in the threshold mode described later with reference to FIG. 65.
The temperature management process of 46 is executed. After this, the process proceeds to step v19, and it is determined whether or not the heating element 146 is in the driven state. If affirmative, in step v20, in the process of FIG. 62 that is repeatedly executed every 1 msec as described above, It is determined whether or not the operating state of the heating element 146 in the previous process is the energized state.

In the previous processing, if the heating element 146 is in the cutoff state, the process proceeds to step v21, and the above step v1
Since the determination of No. 9 is affirmative, the energization history of the heating element 146 is set as the previous energization state, and the heating element 146 is set.
For example, 15 seconds is set as the inspection cycle of. Thereafter, in step v22, it is determined whether or not the inspection time of 15 seconds has elapsed. If it has not elapsed, the operation of the heating element 146 is regarded as normal, and the process returns to the process of FIG. Step v20
If the determination is positive, the process proceeds to step v22 without performing the process of step v21.

The processing of FIG. 62 is thus executed,
When in the threshold mode, the heating element 146 is set to the inspection time 1
Turn on the power for 5 seconds to inspect the temperature change. If this temperature change inspection has been performed even after the inspection time of 15 seconds has elapsed, the error processing of the fixing device 46 shown in FIG. 66 is executed. If the heating element 146 is in the off state in step v19, the history data of the heating element 146 is set to the previous off state in step v23, and the operation state of the heating element 146 is regarded as normal, and the process returns to the process shown in FIG.

FIG. 63 is a flow chart showing details of the process shown in step v4 of FIG. As described above, this process is a process of confirming the temperature range of the heating element 146. In step w1, the thermistor 147 shown in FIG.
An analog amount temperature signal from the analog / data converter 150 is converted into a digital amount of temperature data,
The magnitude relationship with the first specified value corresponding to the dangerous temperature of causing a fire such as 210 ° C. as described above is determined. When the temperature data is larger than the first specified value,
In step w2, it is determined whether the temperature of the heating element 146 can be controlled. This determination is made by performing a short-circuit test on the thermistor 147. When the process of FIG. 63 is executed for the first time, the thermistor 147 is not short-circuit tested and the determination at step w2 becomes negative and step w3 Move on to. At step w3, the CPU 145 sets the short circuit inspection data and sets the energization time for the heating element 146, for example, 25 seconds. In addition, the data under inspection for the thermistor 147 is set, and step w
In step 4, control is performed to cut off the supply of drive power to the heating element 146, and the process proceeds to step v5 in FIG.

When the process of FIG. 63 is the second time or later, the thermistor 147 is under inspection, the determination in step w2 is affirmative, and it is determined in step w5 whether or not the energization time such as 25 seconds has passed. If it has not elapsed, in step w6, control is performed to cut off the supply of drive power to the heating element 146, and the process proceeds to step v5 in FIG. In this manner, the process of cutting off the power supply to the heating element 146 is performed until the power supply time elapses.

If the determination in step w5 is affirmative, it means that the temperature data is greater than the first specified value in the determination in step w1. Therefore, despite the control to bring the heating element 146 into the cutoff state, That is, the temperature data in the state where the temperature rises is obtained from the thermistor 147. Therefore, in step w7, the thermistor 1
A short flag indicating that 47 is in a short state is set, and error processing of the fixing device 46 described later with reference to FIG. 66 is executed.

When the temperature data is smaller than the first specified value in the judgment of the step w1, the step w
It means that the thermistor 147 correctly detects the temperature of the heating element 146 whose temperature drops due to the cutoff control of the heating elements 146 of 4 and w6.
The short flag of No. 7 is cleared, and in step w9, the magnitude relation between the temperature data and the second specified value which is the temperature data corresponding to the break of the thermistor 147 such as 66 ° C. is discriminated.

If the temperature data is smaller than the second specified value in the judgment of step w9, thermistor 1 is selected in step w9.
It is determined whether 47 disconnection inspection is in progress. When the process of FIG. 63 is performed first and the temperature data is smaller than the first specified value and smaller than the second specified value, the thermistor 14 is reached even if the process of step w10 is reached.
The disconnection inspection of No. 7 is not performed, the determination in step w10 is negative, and the CPU 145 sets the disconnection inspection in progress data in step w11 and sets the energization time for the inspection such as 25 seconds. Further, the in-inspection flag of the thermistor 147 is set.

At step w12, the fixing device 46 is energized, and the process returns to step v5 in FIG. On the other hand, step w9
When the temperature data based on the temperature signal from the thermistor 147 is larger than the second specified value, the thermistor 1
47 is operating normally, and step w13
Then, the thermistor open flag indicating that the thermistor 147 is disconnected is cleared, and
The inspection flag corresponding to the in-inspection state is cleared, the thermistor 147 is regarded as normal, and the process returns to step v5 in FIG.

In step w10, the thermistor 147
If the disconnection state is being inspected, it is determined in step w14 whether or not the energization time set in step w11 has elapsed. If it has not elapsed, the heating element 148 is energized in step w15, and the process returns to step v5. In step w14, the temperature data indicating the temperature rise is not output from the thermistor 147, although the heating element 146 is energized for the energization time of 25 seconds after the energization time has elapsed. . Therefore, in step w16, the short-circuit flag of the thermistor 147 is set, and the error processing of the fixing device 46 described later with reference to FIG. 66 is performed.

FIG. 64 is a flow chart showing the details of step v7 in FIG. 62, and it is selected whether the temperature management control of the heating element 146 is performed in the threshold mode or the table mode described above. In step x1,
It is determined whether or not the temperature data based on the temperature signal from the thermistor 147 is (specified value-3) or more with respect to a specified value such as 170 ° C as an example. If the temperature data is below the temperature (specified value-3), it is determined in step x2 whether the temperature data is below the temperature (specified value-8). If the temperature data is larger than the temperature (specified value-8), the process returns to step v8 in Fig. 62 to continue the operation mode relating to the current temperature control.

If the temperature data is equal to or higher than the temperature (specified value -3), the temperature of the heating element 146 is near the specified value,
The determination in step x1 becomes affirmative, the threshold value mode is designated in step x3, the process proceeds to step v8 in FIG. 62, and the energization time to the heating element 146 is controlled so that the temperature of the heating element 146 converges to the designated value. Performs temperature management in threshold mode. When the temperature data is equal to or lower than the temperature (specified value-8), the heating element 146 has the standby temperature which is about room temperature immediately after the power is turned on, or the operating temperature which is about the standby temperature. At this time, step x
When the determination of No. 2 is affirmative, the process moves to step x4, the table mode for managing the energization period to the heating element 146 is designated based on the duty table 163 described with reference to FIG. 12, and the process moves to step v8 in FIG. Temperature control is performed in a table mode that prevents rapid temperature rise and overshoot.

FIG. 65 is a flow chart showing details of the process of step v18 of FIG. In the present embodiment, when the temperature data obtained by digitizing the temperature signal from the thermistor 147 is adopted for the temperature control, the temperature data is accumulated every time the process of FIG. 62 is executed every 1 msec. The processing is performed by using the average value of. That is, at step y1 in FIG. 65, the temperature data from the analog / digital converter 150 is added to the temperature data read at the time of the process of FIG. 65 last time, and at step y2, it is judged whether or not this addition is performed 16 times. To do. If the determination is negative, the process proceeds to step v19 in FIG.

If the addition of the temperature data is performed 16 times and the determination in step y2 becomes affirmative, the temperature data for 16 times is averaged in step y3, and the average value and the temperature instruction value by the CPU 145 are calculated in step y4. Determine the magnitude relationship. If the average value is larger than the indicated value, step y5
Then, the power supply to the heating element 146 is cut off, and the process proceeds to step y7. If the average value is smaller than the indicated value, step y6
Then, the heating element 146 is energized, the total addition memory is cleared in step y7, the number of times of addition 16 is newly set, and the process proceeds to step v19.

The reason for adding the temperature data 16 times in the process of FIG. 65 is as follows. As shown in FIG. 11, the power applied to the heating element 146 is, for example, 60H.
It is a commercial AC power supply of z100V, and its cycle is 1/60
= 0.017 = 17 msec. That is, when the process of FIG. 65 is performed every 1 msec, 16 times are added, and the averaging process is performed, about 1/60 sec is elapsed. That is, the energization or interruption operation to the heating element 146 in steps y5 and y6 of FIG. 65 can be executed at the zero cross timing to the commercial AC power supply of 60 Hz and 100 V.

FIG. 66 is a flow chart showing details of the error processing of the fixing device 46 described with reference to FIG. In step z1 of FIG. 64, the engine controller 1
The status data transmitted from 31 to the image controller 130 is abnormal data indicating that the processing of the fixing device 46 is abnormal, and the abnormal state of the fixing device 46 is a serious one which is not recovered by the maintenance and inspection work of the user. Set the call service occurrence data to the effect that it is necessary to call a specialized repair staff. In step z2, the heating element 1
The power supply to 46 is cut off, and the temperature control flag of the heating element 146 in the engine controller 131 is cleared.
At step z3, steps f3 and f7 shown in FIG.
The output initialization process referred to in step 1 is performed. After this, the process returns to step v1 in FIG. 62, and the above-described process is repeated.

FIG. 62 Each judgment step v1, v5, v8,
If the various judgment conditions in v11, v14, v16, v19, V20, and V22 are the same, the error process of the fixing device 46 in FIG. 66 is performed again in the process of FIG. 62 executed in the next execution cycle of 1 msec. Be seen. In this way
As long as the same operating condition of the LED printer 21 continues, starting from step v1 in FIG. 62, step v16,
An endless loop in which a process in which the process of making v22 affirmative is connected to the process shown in FIG. 66 is repeatedly performed is configured.

As previously mentioned, FIG. 62, and thus FIG.
The process of 6 is also an interrupt process executed every 1 msec, and if the various operating conditions referred to in each determination step of FIG. 62 are changed as the operation of the LED printer 21 progresses, the process is infinite. Leave the loop.

67 is a time chart relating to the operation of the CPU 145 shown in FIG. 11, FIG. 68 is a graph for explaining the temperature control of the fixing device 46 of the LED printer 21, and FIG. 69 is a thermistor 147 of FIG. It is a graph explaining a characteristic.

The LED printer 21 of this embodiment manages the temperature of the fixing device 46 by software control. However, when the CPU 145 runs out of control, the fixing device 4 can be operated.
It becomes impossible to manage the temperature of No. 6 by software, and the heating roller 49 of the fixing device 46 is installed in FIG.
The heating element 146 shown in (1) may have an abnormally high temperature, which may cause thermal damage, smoke emission, or fire. Therefore, in the LED printer 21 of the present embodiment, the temperature of the heating element 146 is detected with the configuration shown in FIG. 11, and when an abnormally high temperature is detected, the CPU 145 is forcibly reset as a circuit operation.

The CPU 145 shown in FIG.
The watchdog timer circuit 1 outputs the signal of the constant period of (1).
51, and the watchdog timer circuit 151 outputs
7 (2), a high-level signal is input to the CPU 145 and reset is not performed. The watchdog timer circuit 162 detects the runaway of the CPU 145. When the watchdog timer circuit 162 detects the runaway of the CPU 145 which appears as the loss of the signal in FIG.
The signal of 7 (2) is set to the low level to generate the reset signal, and the CPU 145, that is, the engine controller 131
Stop driving. However, as shown in FIG. 67 (3), the signal from the CPU 145 may not be lost and may have an indefinite cycle. With such a runaway content of the CPU 145, the watchdog timer circuit 151 cannot detect the runaway of the CPU 145.

That is, the output of the thermistor 147 is as shown in FIG.
If the temperature range is appropriate as shown in 8 (1), the comparator 152 outputs a high-level signal, the transistor 159 is in the conductive state, and the transistor 160 is in the conductive state. As a result, the transistors 161, 15
4 is applied with a high level bias voltage,
The control signal from the gate array 134 under the control of 5 is
By being applied to the transistor 161 or the transistor 154, the motor 126 or the heating element 14
6 is driven.

The output of the thermistor 147 is shown in FIG. 68 (1).
When the upper limit value indicated by the reference voltage generation circuit 153 such as 170 ° C., which is an example of the appropriate temperature of the above, is exceeded, the comparator 152 outputs a low level signal and the transistors 159, 16
0, and CPU 145 and gate array 13
4 is forcibly reset by the reset signal RS shown in FIG. 68 (3). As a result, the transistor 161,
154 is cut off, the motor 126 is stopped, and the supply of drive power to the heating element 146 is stopped. Therefore, the temperature drops as shown in FIG. 68 (2).

That is, in the LED printer 21 having such a configuration, the CPU 145 and the gate array 134 are reset while the fuse 157 is not blown when the CPU 145 runs away and the heat generating element 146 becomes abnormally high temperature. The driving of the heating element 146 is stopped.
As a result, as compared with the case where the control of the heating element 146 is performed only by the program control by the engine controller 131, the control of the heating element 146 becomes impossible and the heating element 14
It is possible to prevent the risk of causing damage due to heat, smoking, fire, or the like, which causes abnormal temperature rise in 6.

In performing such temperature control operation,
The temperature / resistance value characteristic of the thermistor 147 is a monotonically increasing curve that is convex downward as shown by a line 231 in FIG. That is, in the temperature control operation of the present embodiment described with reference to FIGS. 62 to 66, when the temperature control is performed in the table mode, the temperature becomes high as described with reference to the duty table 163 of FIG. The more gradually the temperature rise per unit time is controlled. Such control is possible because the higher the characteristic of the thermistor 147 is,
Change range of resistance value with respect to unit temperature change, that is, FIG.
This is because the change width of the output voltage from the thermistor 147 of No. 1 becomes large. Accordingly, the higher the temperature becomes, the more accurately the temperature control can be performed using the thermistor 147.

FIG. 70 shows a process for determining the control mode of the rotation speed of the motor 126, which is executed as an interrupt process every 1 msec like the process shown in FIG. The CPU 145 of the engine controller 131 shown in FIG. 1 has a memory in which speed data for controlling the rotation speed of the motor 126, which is a pulse motor, is stored in advance. The pulse motor 126 has, for example, four phases, and the combination of application of drive power to the four-phase winding is mutually switched at predetermined intervals to rotate the motor 126 in one predetermined direction, or It can be rotated in the other direction. Such switching of drive power to the four-phase windings of the motor 126 is referred to as a step below. That is, the speed data table stores the number of executions of the step of switching the drive power to the motor 126 and the data of the execution period in which the number of executions of the step should be performed. This execution period includes an infinite period, and such data is
26 is used when continuing the constant speed rotation.

In step α1 of FIG. 70, it is determined whether or not the motor 126 has the same cycle, that is, the execution period, and within the execution period, the rotation is performed by the number of steps stored in the data table. If this determination is negative and the motor 126 is rotating at a constant speed, the process returns to FIG. Assume that the determination in step α1 is affirmative and the motor 126 is accelerating or decelerating. At this time, the process proceeds to step α2, and it is determined whether or not the read pointer indicating the data read position in the data table is the final position in the read table. If it is not at the final position, acceleration or deceleration has not been completed, and at step α2,
Based on the data read from the final address of the data table, the process proceeds to step α3, the predetermined movement number is set, the table data is set in the cycle timer, and the read pointer is updated.

If the determination in step α2 is affirmative and the read pointer indicating the data position in the data table indicates the final position in the data table, the motor 12
6 has reached the final stage of either acceleration or deceleration processing. At this time, the process proceeds to step α4 to determine whether or not the motor 126 is accelerating. If the vehicle is accelerating, it means that the accelerating operation has been completed, and the routine proceeds to step α5, where the constant speed rotation flag is set and the acceleration flag is cleared. After this, the process is performed as shown in FIG.
Return to 7. If the determination in step α4 is negative, the motor 126 is currently in the deceleration operation end state, and step α6
Then, the cycle timer is stopped and the output of each voltage of the excitation phase to the motor 126 is stopped. In addition, the deceleration flag is cleared, and the process returns to FIG.

[0246]

As described above, according to the present invention, the switch means for disconnecting / outputting the power source power is provided in association with the cover body depending on the open / closed state of the cover body.
The power supply from the switch means is supplied to the drive mechanism, while the detecting means is connected to the switch means. The detection means detects the cutoff state of the power source power in the switch means, and the open state of the cover body is detected.

Therefore, by providing a single switch means in association with the cover body, it is possible to combine the cutoff / output switching of the power supply to the inside of the electronic device and the detection of the open / closed state of the cover body. It can be carried out. As a result, the number of parts of the electronic device can be reduced and the configuration can be simplified.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall electrical configuration of an LED printer 21 according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of the LED printer 21.

FIG. 3 is another vertical cross-sectional view of the LED printer 21.

FIG. 4 is a plan view of the LED printer 21.

FIG. 5 is a perspective view showing the back surface of the LED printer 21.

FIG. 6 is a diagram around a power feeding member 107.

FIG. 7 is a perspective view showing a relationship between a discharger 11 and a photosensitive drum 77.

FIG. 8 is a sectional view of a process cartridge 73.

FIG. 9 is a block diagram related to a cover switch 217.

FIG. 10 is a block diagram showing an electrical configuration of an LED array 82.

11 is a block diagram showing a configuration relating to temperature control of the fixing device 46 of the LED printer 21. FIG.

FIG. 12 is a diagram showing stored contents of a duty table 163.

FIG. 13 is a block diagram showing a configuration of an engine controller 131.

FIG. 14 is a block diagram showing a detailed configuration of an engine controller 131.

FIG. 15 is a diagram showing stored contents of a ROM 133.

16 is a block diagram showing a configuration related to an output operation of a signal to each component in the engine controller 131. FIG.

FIG. 17 is a block diagram illustrating the operation of FIG.

FIG. 18 is a block diagram showing a shift clock adjustment mechanism in the LED printer 21.

FIG. 19 is a block diagram showing details of the configuration of FIG. 18.

20 is a block diagram showing a configuration of a gate array 134. FIG.

FIG. 21 is a transition diagram illustrating an overall operation of the LED printer 21.

FIG. 22 is a transition diagram illustrating a printing operation of the LED printer 21.

FIG. 23 is a transition diagram illustrating a recording paper feed mode of the LED printer 21.

FIG. 24 is a transition diagram illustrating a toner supply operation of the LED printer 21.

FIG. 25 is a transition diagram illustrating a temperature control operation of the fixing device 46 of the LED printer 21.

FIG. 26 is a transition diagram illustrating error processing of the LED printer 21.

FIG. 27 is a flowchart illustrating the entire operation of the LED printer 21.

FIG. 28 is a waveform diagram showing an operation when the LED printer 21 is powered on.

FIG. 29 is a timing chart illustrating synchronization adjustment of a shift clock.

FIG. 30 is a timing chart illustrating details of the synchronization adjustment.

FIG. 31 is a timing chart for explaining a strobe signal generating mechanism in the present embodiment.

FIG. 32 is a time chart explaining the operation when the LED printer 21 is powered on.

FIG. 33 is a flowchart showing details of the process of step a2 of FIG. 27.

FIG. 34 is a flowchart showing details of the process of step a3 of FIG. 27.

FIG. 35 is a flowchart showing details of the processing in step a4 of FIG. 27.

FIG. 36 is a flowchart showing details of the processing in step a6 in FIG. 27.

FIG. 37 is a flowchart showing details of the process of step e3 of FIG. 36.

FIG. 38 is a flowchart showing details of the process of step a7 of FIG. 27.

FIG. 39 is a timing chart illustrating a printing operation according to this embodiment.

FIG. 40 is a flowchart showing details of the processing in step a8 of FIG. 27.

FIG. 41 is a timing chart illustrating a printing operation in this embodiment.

FIG. 42 is a flowchart showing details of the processing in step a9 in FIG.

FIG. 43 is a diagram illustrating a recording paper conveyance operation in the LED printer 21.

FIG. 44 is a timing chart illustrating the printing operation of this embodiment.

FIG. 45 is a timing chart illustrating the printing operation of the present embodiment.

FIG. 46 is a flowchart showing details of the processing in step i1 in FIG.

FIG. 47 is a flowchart showing details of the process of step i3 of FIG.

FIG. 48 is a flowchart showing details of the process of step i4 of FIG.

FIG. 49 is a flowchart illustrating output of a control signal VSRQ from the engine controller 131 to the image controller 130.

FIG. 50 is a flowchart showing details of the process of step i5 of FIG. 42.

51 is a flowchart showing details of step i21 in FIG. 42. FIG.

FIG. 52 is a timing chart illustrating an operation from a print operation to a print stop operation in the present embodiment.

FIG. 53 is a timing chart illustrating a print stop operation according to the present embodiment.

FIG. 54 is a timing chart illustrating the relationship between various control signals and print data VD in this embodiment.

FIG. 55 is a timing chart illustrating the relationship between various control signals and the horizontal synchronization signal BD in this embodiment.

FIG. 56 is a timing chart illustrating the relationship between the horizontal synchronization signal BD and the print data VD.

FIG. 57 is a flowchart illustrating processing executed in interrupt processing every 1 msec in this embodiment.

FIG. 58 is a flowchart illustrating the details of the process in step q32 of FIG. 57.

FIG. 59 is a flowchart illustrating the details of the processing in step q33 in FIG. 57.

FIG. 60 is a flowchart illustrating the details of the processing in step q34 in FIG. 57.

FIG. 61 is a flowchart illustrating the details of the processing in step q35 in FIG. 57.

FIG. 62 is a flowchart illustrating another process executed by interruption every 1 msec in this example.

FIG. 63 is a flowchart illustrating the details of the process of step v4 of FIG. 62.

FIG. 64 is a flowchart illustrating the details of the process of step v7 of FIG. 62;

FIG. 65 is a flowchart illustrating the details of the process of step v18 of FIG. 62;

66 is a flowchart illustrating error processing executed after steps v16 and v22 in FIG. 62. FIG.

67 is a time chart illustrating an operation of detecting runaway of the CPU 145 in the LED printer 21. FIG.

68 is a waveform diagram illustrating a temperature management operation of the fixing device 46. FIG.

FIG. 69 is a graph illustrating characteristics of the thermistor 147.

FIG. 70 is a flowchart showing an example of processing executed by interruption every 1 msec.

FIG. 71 is a system diagram showing a configuration of a conventional example.

[Explanation of symbols]

 21 LED Printer 23 Upper Housing 25 Recording Paper 29 Paper Feed Cassette 30 Paper Feed Roller 33.39, 51, 87 Sensor 38 Registration Roller 42 Transfer Device 46 Fixing Device 73 Process Cartridge 74 Toner Box 76 Developing Roller 77 Photosensitive Drum 81 Charger 82 LED head 99 Waste toner box 107, 224 Power supply member 110 Detection switch 118 Toner supply roller 124 Electromagnet 126 Motor 130 Image controller 131 Engine controller 132 Timer 134 Gate array 145 CPU 146 Heating element 147 Thermistor 158 Voltage monitoring circuit 163 Duty table 214 Toner motor 215 1st general purpose counter 216 2nd general purpose counter 217 Cover switch

Claims (1)

[Claims] 1. A box-shaped housing having an opening at one end,
An electronic device comprising: a cover body that opens / closes an opening portion of a housing; and a switch unit that is provided in association with the cover body and that cuts / outputs power source power in accordance with the open / closed state of the cover body. In an electronic device having a drive mechanism connected to the switch means for applying / cutting off the power source, the cutoff / output state of the power source connected to the switch means is detected to detect the open / closed state of the cover body. An electronic device comprising a detection means.