JPS6254281A - Control device in copying machine and the like - Google Patents

Abstract

PURPOSE:To easily change setting time and to detect correctly by using a counting-up signal and executing the control realted to the rear edge of recording paper. CONSTITUTION:To the first timer TM1, the numerical data in proportion to the conveying path length from the starting edge of the copying paper conveying path to a setting position P1 of a copying paper detecting device 40-1 are preset, to the second timer TM2, the first numerical data and the numerical data in proportion to the dimensions from the front edge to the rear edge of the copying paper are added and preset, in the same time with the conveying of the copying paper, the reference clock pulse from a pulse generating device PG1 is inputted and the clocking operation is started. When the timer TM1 counts up by the paper blocking logic determining circuit formed at an input output interface circuit I/oIF, the logic determination is executed with the input signal from an input port A, it is decided whether or not the copying paper detecting device 40-1 detects the front edge of the copying paper, and when a timer TM2 counts up, it is decided whether or not the detecting device 40-1 detects the rear edge of the copying paper. The sending of the signal to output ports B and C is determined.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper jam detection device for a copying machine such as an electrophotographic copying machine, and more particularly to a paper jam detection device using a digital timer.

Conventionally, as a certificate stamp jam detection device, an appropriate position on a copy paper conveyance path is selected at a place where a paper jam occurs, such as a copy paper supply mechanism section, a transfer mechanism section, an original image mechanism section, etc. A detection means for detecting the presence or absence of copy paper, such as a microswitch or a photocoupler, is installed at the paper jam detection position, and an electromagnetic type that times up at a timing commensurate with the copying sequence control corresponding to each detection means is installed. A timer means is installed, and when the detection means corresponding to the timer means does not detect the front edge of the copy paper by the time the electromagnetic timer means times up, that is, the copy paper does not reach the detection position, the copy paper transport is stopped. There is a known structure in which a paper jam signal generating means is provided for determining that copy paper is jammed at a position upstream of the detection position of the path and outputting a paper jam detection signal.

However, depending on the conventional paper jam detection device described above,
If a paper jam occurs immediately after the front edge of the copy paper passes a certain detection position, the detection means installed at the detection position is in a state of detecting the copy paper, and therefore the paper jam signal generation means The paper jam detection signal is not output from the
It is not possible to detect the occurrence of a paper jam at the detection position. In addition, if there is a similar detection means downstream from the detection position, this paper jam will be detected when the timer corresponding to the detection means installed at that detection position operates, but this detection means will be instructed to operate. There is also a drawback that there is a delay in detecting a paper jam for a time corresponding to the time set in the timer means, which may cause damage to the inside of the machine.

For this reason, a timer is set for each predetermined detection means in accordance with the timing at which the leading edge and trailing edge of the conveyed copy paper pass therethrough (7, within this timer time, the trailing edge of the copy paper A method has been proposed in which a paper jam can be detected even when the paper has not completely passed through the detection means, but with this method, it is necessary to know the length of the copy paper in order to check that the trailing edge of the copy paper has passed. , it is necessary to delay the timer by that much compared to the timer that checks and checks the passage of the tip.

In this case, if only one type of copy paper is being used, setting the timer for that timer is not a big problem, but as with modern copy machines, it is relatively easy to change the size of the copy paper used by replacing the cassette. If the timer can be changed, the timer for checking the trailing edge must be able to change the time depending on the size, or the timer can be used differently depending on the size of copy paper that can be used. Conventional methods that use analog timers have the disadvantage of being technically difficult and lacking in reliability of setting time; the latter is disadvantageous in terms of cost;
This has the disadvantage that the circuit configuration becomes complicated.

Furthermore, in such a paper jam detection mechanism, when a paper jam occurs, it is necessary to detect it as soon as possible and perform controls such as stopping the drive. It is necessary to improve the accuracy of the conveyance speed.

However, no matter how much accuracy is improved mechanically, there is a limit to the accuracy of the copy paper conveyance speed because the rotational speed of the drive motor changes to some extent due to voltage fluctuations, etc. Therefore, paper jam detection is difficult. The timer itself had to be set with a certain amount of time margin, which caused a delay in the timing of paper jam detection.

Therefore, coupled with the difficulty in setting the timer for detecting paper jams at the rear end as described above, a fully satisfactory mechanism for detecting paper jams has not yet been realized. be.

The present invention has been made with attention to these points, and is a digital timer that counts pulse signals and outputs a time-up signal when the counted value reaches a preset value. By using the formula timer and generating a pulse signal as the drive motor rotates, even if the conveying speed of the copy paper varies, the timer time-up time changes in response to the speed variation. Therefore, it is an object of the present invention to provide a paper jam detection device that allows easy change of setting time and can perform accurate detection.

Next, a paper jam detection device according to the present invention will be explained with reference to the accompanying drawings.

FIG. 1 shows a slit exposure type electrophotographic copying machine with a moving optical system to which the present invention can be applied, in which a light source 2 and reflecting mirrors 3a and 3b can be scanned to the left in the figure, and are set at predetermined positions. +
- An optical system scanning mechanism A is constructed in which synchronization is achieved with the image forming operation on the copying machine by turning on a switch SW such as a switch. Original table 4
A document (not shown) placed on the is continuously irradiated by the light source 2, and the reflected light (shown as a straight line) is reflected by the reflecting mirror 3a.

3b, an imaging lens 5, and a reflecting mirror 6.7 to reach the photosensitive drum 8. The photosensitive drum 8
is rotationally driven in the counterclockwise direction in the figure by the rotational force of a motor (not shown), and after being uniformly charged by the charging charger 9, the image is exposed by the optical system, and the photoconductive layer on the surface is exposed]) 7j forms an electrostatic latent image of the original, and develops the image with the developing device 13 to form a visible image with toner, and these constitute an image forming mechanism B.

On the other hand, copy sheets (not shown) of predetermined dimensions stored in the paper feed cassettes Oa and IOb are transported by the motor.
selectively driven paper feed roller lea;

A copy paper supply mechanism C having a copy paper supply mechanism C having a copy paper feed mechanism C feeds the copy paper one by one to the lower part of the photoreceptor drum 8, and transfers the copy paper to the transfer charger 14.
The toner image of the electrostatic latent image formed on the surface of the photoreceptor drum 8 by the magnetic plan method is transferred onto copy paper by a transfer mechanism having a transfer mechanism. The copy paper subjected to the transfer process is separated from the photoreceptor drum 8 by a separation claw 15, and is then separated by a conveyance roller 1 driven by the motor.
2. The transfer sheet is transported to the fixing mechanism F by the transfer paper transport mechanism E, which has a transport belt 17 with a built-in static eliminator 1G. It has a fixing mechanism Ill, a heat roller I8, and a presser roller I9, and the copy paper is passed between both rollers 18 and 19 to fuse and fix the toner image. Thereafter, the copy paper is discharged onto the tray 21 by the discharge roller 20, and the photosensitive drum 8 is driven to rotate for a predetermined period of time, and the residual toner is removed by the cleaning device 22. In this way, one copy process is completed. is set to end.

FIG. 2 shows a digital timer 30 that can be applied to the present invention, and includes a counter 31 (for example, a 6-bit polynomial counter) that divides the pulse train signal (indicated by Cr in the figure) as appropriate, and an operation time (setting). A programmable binary counter 32 (hereinafter simply referred to as a preset counter) that presets binary numerical data of time data and counts down each time a pulse train signal from the counter 31 is input.

The preset counter 32 receives a count-up signal (a 1-by-1 polllow signal) when its count value becomes a negative value.
This signal is input to the set terminal S of the flip-flop circuit 33 to set the flip-flop circuit 33.

The flip-flop circuit 33 has its reset terminal H
, manually set the timer operation start command signal STM (1 pulse), and as described above, preset the operation time data in the preset counter 32 and count the pulse train signal input from the counter 31. A timing operation is performed by the Q output signal, and the timing of the operation command to the controlled object is determined based on the Q output signal.

Note that the preset counter 32ij of the digital timer (hereinafter simply referred to as timer TM).

−8= As shown in FIG. 3, it is configured by using, for example, a central processing unit of a microcomputer without a CPU (in this example, it is assumed that there is a tel, 8). Alternatively, the output of the flip-flop 33 may be further counted by a shift register or the like.

The two bits of the most significant digit (MBS-1) and the next lowest digit (MBS-1) of the above-mentioned shift register are assigned as an end flag and a request flag, respectively, and the operating time data (binary value to be set is The remaining 6 bits may be allocated so as to be able to preset a value obtained by converting the shift register into a complement and adding l (hereinafter, this shift register will be referred to as a count section 32°).

When the operation time data is preset, the counting section 32° outputs "O" and "Jl" as the end flag and request flag, respectively, and when counting up (Jl, "Jl" and "Jl" respectively). 0°', and it is possible to determine the timing of the actuation command to the controlled object based on these signal changes.

FIG. 4 shows an embodiment of a copy paper detection means whose operation is controlled by the timer TM (30), in which a light receiving element PE (for example, cadmium sulfide A photoelectric coupler 41 consisting of a CdS photoelectric element) and a light emitting lamp L, the light receiving element PE, and a resistor R.
,, a bridge circuit 42 formed by R2, a resistor R3, and a variable resistor RT, and a neutral point NP of the bridge circuit 42,
It consists of a comparator 43 that detects and amplifies the potential difference between NPR, and an output terminal OUT formed by interposing a diode D in series with the output terminal T of the comparator 43. It is abbreviated as vessel 40.

The copy paper detector 40 is disposed at a desired position on a copy paper transport path formed from the copy paper supply mechanism C of the copying machine I to the image forming mechanism B, the transfer mechanism D1, the fixing mechanism F, and the tray 21. For example, as shown schematically in FIG. 5, there is a downstream position P7 near the transport roller 12 in the copy paper transport path PTL7, a downstream position P2 near the photosensitive drum 8, and a downstream position P3 near the heat roller 18. These copy paper detection means are arranged at 40-], 40-2, and 40-2, respectively.
It is written as ±0-3.

Next, the three copy paper detection clansmen-0--] mentioned above.

]±0-2. A digital control device for controlling ±-3 will be explained.

In FIG. 6, the digital control device 50 is a so-called micro combicoater, and includes a timing control section TCC, a buffer BUF, and a register, which is formed by an arithmetic unit ALU, an agicomulator ACC, a program counter PC, an instruction decoder DEC, a timer TMo, etc. A pointer DPf-f, DP(.

A micro central processing unit CPU (hereinafter abbreviated as CPU) and a random access memory T (AM, read-only memory R
Storage section ME consisting of OM, stack memory 5TACK, etc.
and a human output interface circuit 110IF are connected to each other by a pass line T3US.

The input ports Δ, B, and C of the input/output interface circuit 110TF are series bodies of a diode and the collector of a transistor, D, and Tr+, D2, Tr, and D3, respectively.
and Tr3, and each transistor Try, Tr3
, Tr3 respectively connect each base to the copy paper detector ±O-1. Engineering vessel 2 2. ±''-13 output terminal OUT, and each emitter is commonly connected to output port A. The input boat D is connected to a pulse generator PC that generates a pulse signal (reference clock pulse) of a predetermined frequency, and the human-powered boat E is driven by the rotational force of a drive motor (not shown) in conjunction with the copying machine. A drive mechanism related to copy paper conveyance, for example, a paper feed roller l on the copy machine.
A disk (not shown) having slits provided at a desired center angle pitch on the circumference is attached to a rotating shaft (not shown) of the photosensitive drum 8, etc., and as the disk rotates, It is connected to the output terminal of a pulse generator PG2 having a photoelectric coupler (not shown) that is synchronized with the rotation and generates a pulse train signal with a time interval proportional to the rotation speed.

Furthermore, output ports B and C are located at the paper jam position (
A drum (not shown) on which the transfer paper detector/10-1.2.3 is marked on its circumferential surface is moved at a predetermined angle via a mold wheel (not shown) that is driven step by step by an electromagnetic relay. It is connected to a paper jam position display device (only the solenoid SOT of the electromagnetic relay is shown) which is configured to be rotated in steps, and an indicator lamp E'L that indicates the occurrence of a paper jam. In addition, other horn boats n (n is 1.2.
. and those connected to the switch mechanism (not shown) of the drive mechanism (solenoid for the clutch mechanism connected to the output shaft of the drive motor) designated as the control target. There is.

The storage unit ME of the CPU specifies, in advance, each device connected to the input/output ports A, B, . . . , D, n of the input/output interface circuit 110TF' as a control target, A control program incorporating operation commands, operation time data, etc. for the specified control object is stored, and as is well known, the storage section ME
Based on the operation command and operation time data read out sequentially from It is supposed to be done.

The timer TMotJ of the timing control unit TCC generates a pulse train signal to be input to the plurality of timers TM formed in the RAM area as described above, and appropriately divides the reference clock pulse input from the pulse generator PG. This pulse train signal is input to each timer TM, and each timer T
``M'' performs a timing operation based on the operation time data (numerical data) stored in the counter section (32') and determines the timing of an operation command for a predetermined control object.

Note that the timing of the operation command for the drive mechanism related to the conveyance of copy paper on the copying machine (J1)
1 to determine based on the pulse train signal outputted from 2, and (J1) transmit the rotational operation time data to the drive mechanism to the timer TM.
T''Mo generates a pulse train signal with the same 1[+1 t as the pulse train signal of the pulse generator PG2, and the timer 'l''M is deactivated based on this pulse train signal. In this way, the timer TM
The timing of the operation command for the drive mechanism, which is determined by Based on voltage fluctuations, etc.
Or (based on the differences in the model of J1 copier 1-, etc.)
Even if there is variation, it is possible to completely prevent the timing shift of the actuation command without being affected by it.

In this way, the copy paper detector A-9-(±n-
1, 4Q-2, 4-Q-3) can prevent the timing shift for the judgment operation of detecting a paper jam based on the detection of the passage of copy paper = 15-, thereby preventing incorrect judgment of paper jam detection. The risk of this occurring can be minimized.

Next, the digital control device 50 controls the three transfer paper detectors 0-1. The operation of controlling the ±(]-2° Kamimachi-3 to detect a paper jam in the copying machine 1 will be explained.

It is now assumed that the scanning mechanism A of the copying machine I has started operating. That is, the light source 2 and reflecting mirrors 3a and 3b of the copying machine-1- are set at predetermined positions, and the original platen 4 is
Start exposure scanning for the original (switch SW in Figure 1)
, is on).

First, in the timing control unit TCC, there are "two timers i" configured using the RA and M areas in a double series.
One of the first timers T M + of M includes a copy paper detector 4. −． The first value for 5 is proportional to the conveyance path length up to the installation position 1 of 0-1.
The clock is preset and the second timer ', 1'
M2 contains [1[j numerical data of memory 1 and the copy paper transport path! '16 from the front edge of the stone copy paper sent to TL
and the second numerical data proportional to the dimension to one end)
This numerical data is preset.

Now, the copying machine starts the copying operation, and the copy paper is transferred from the paper feed cassette J-10a to the copy paper transport path 'FPl,
At the same time, the timer 'r
M,,'r'Mpij, said pulse generator PC.

A reference clock pulse is input from the input terminal to start timekeeping operation. Also, at this time, a signal at a predetermined voltage level is output to the output port A of the input/output interface circuit r101P, and the transistors rr, Tr, connected to each input port A, B, and C.

The signal from the output port Δ is applied to the emitter of 'r''r3.
All the copy sheets conveyed from 10a and IOh are discharged onto the tray 21, and are outputted until they reach the tray 21.

1"Ifi When the first timer 'I'M, counts up (when its end flag becomes the same), the paper jam logic determining circuit 9IΔM L, ( For example, an AND circuit etc.) is used to determine whether the signal input from the input port A and the timer TM are time-up (end flag l).
”) signal to determine whether the front edge of the copy paper is detected by the copy paper detector ±O-1.Now, the photoelectric coupler 41 of the copy paper detector ±O-1 is connected to the Assuming that the leading edge of the paper has passed, the potential at the output terminal T of the comparator 43 decreases.
The bridge circuit 42 (40-2, 3) is adjusted in advance to a balanced state by the variable resistor TR in a state in which the copy paper does not pass through the photoelectric coupler 41 (a state in which it is in the position of the photoelectric coupler 41), Since the light receiving element PE of the photoelectric coupler 41 is blocked from the light from the projecting lamp L by the copy paper, the bridge circuit 42 becomes unbalanced, and the comparator 43 is connected between the neutral points NP, NP3. This is because the voltage corresponding to the potential difference is amplified and output to the output terminal T, and the potential of the output terminal T is lowered.

In this way, the base potential of the transistor Tr+ decreases and becomes conductive, and a signal "1" is input to the input port A. In this case, the logic determining circuit, I
A M L determines that there is no paper jam and prohibits the sending of operating signals to the solenoid S Q L of the display device connected to the output boats B and C and the display lamp EL. Furthermore, at this time, the first timer TM receives the following first numerical data, that is, the arrangement position P2 of the detector 40-2.
The reference clock pulse is preset according to the reference clock pulse, and as described above, the timekeeping operation is started based on the reference clock pulse.

When the second timer TM counts up, the logic decision circuit IAML receives the signal input from the input port A and the timer TM, as described above.
A logic decision is made based on the time-up (end flag flag) signal of No. 2, and the signal transmission to the output ports B and C is determined according to the decision result.

Now, if the detector ±01 does not detect the trailing edge of the copy paper and it is determined that there is no copy paper, the signal to the input port is "0" and the logic decision is made. circuit J
AML determines that there is no paper jam and prohibits the output ports B and C from transmitting the above-mentioned signals. Further, at this time, the second timer TMe is preset with the next first numerical data, that is, the same numerical data as the data preset in the first timer TM, as operating time data, and the reference clock A time measurement operation is started based on the pulse.

Hereinafter, in the same manner, the first and second timers TM,
, TM, are preset with first numerical data corresponding to the setting position P3 of the copy paper detector period-3 and numerical data obtained by adding the first numerical data and the second numerical data. Ru.

Then, when each timer TM, TM2 times up, the logic determining circuit J
AML is activated to determine whether a paper jam has occurred at the position P3.

Note that when the first and second timers TM, TM2 time up, the pulse of the signal (end flag) input to the logic determining circuit JAML is appropriately adjusted by a flip-flop circuit (not shown), etc. The operating time (copy paper detection operating time) of the paper detector 40-1.4 East-2, ±0-3 is adjusted.

Further, when the paper jam logic determination circuit JAML detects the occurrence of a paper jam, that is, when the first timer TMI times up, each copy paper detection pattern 0-], 2.3
does not detect the passage of the leading edge of the copy paper, and
When the second timer TM2 times up, if each copy paper detector 40-1, 2.3 does not detect the passing of the trailing edge of the copy paper, that is, it detects the presence of the copy paper, , by a decoder and pulse generator (not shown),
According to the addresses (channels) of input ports 1-A, B, and C, a pulse train signal of a predetermined number of pulses is sent to output port B, and a predetermined level voltage signal is sent to output port C. Display device drive solenoid SQL,
Activate the indicator lamp EL.

Furthermore, the first and second timers T M +
.

The numerical data to be preset in TMx is determined by, for example, determining which of the paper feed rollers Ila and Ilb of the copying machine 1 has been commanded to operate, and also determines which of the paper feed rollers Ila and Ilb of the copying machine 1 has been instructed to operate, and also determines which of the paper feed rollers Ila and Ilb of the copying machine 1 corresponds to the paper feed rollers Ila and Ilb. Data corresponding to the dimensions of the copy sheets stored in the cassettes IOa, 10b may be stored in advance in the storage section of the control device 50, and the decision may be made based on the logic decision signal of the logic decision circuit. . This copy paper size detection means sends operation time data to the second timer TM2, that is,
It is activated when presetting the set time data and stores second numerical data i'j in the second timer T M 2.

The timing of the activation command for the copy paper detectors 1, 2, and 3 explained below is determined by instructing the first and second timers TM, TM, respectively. Instead of presetting and determining data determined based on the numerical data of , a control program for a drive mechanism related to copy paper conveyance on the copying machine may be used.

An example of detecting a paper jam using the control program is shown in the control flowchart shown in FIG. 7 and the time chart shown in FIG.
1 will be explained accordingly.

In FIG. 7, the switch S W + is the copying machine -
This is a switch for starting the exposure scan of the scanning mechanism A (see FIG. 1) of L, and is operated by a predetermined timer TM of the timing control section TCC.
mer-1, 2, and -8 are the image forming mechanism 13 on the copying machine, respectively, as shown in time chart 1 of FIG.
The separation claw j5 is driven by a TM (30 ).

The reference timer in step ① is the digital control device (
The micro combicoater υ is similar to the timer TMo, and converts the reference clock pulse of the pulse generator PG into a pulse train signal synchronized with the pulse generator PG2. The timer TM is programmed to perform counting according to the converted pulse train signal.

In step (2), at the same time as the copying machine is started, second numerical data corresponding to the size of the copy paper carried out to the copy paper transport path PTL is preset to Timer=3, and this Timer- 3 starts the timing operation.

The determinations in steps ①, ＠, and 0 are made by detecting the passing of the leading edge of the copy paper by the copy paper detector 1 and 21, and determining whether or not the front edge of the copy paper has passed by the copy paper detector 1 and 3, and step 12, which determines whether the front edge of the copy paper has passed, and step 12. The determination in is made by the detector
0-2, -4-0--3, it is determined whether the passage of the trailing edge of the copy paper is detected.

In this case, the input/output interface circuit T/.

In the former case, the paper jam logic determination circuit JAMT of T F determines the logic based on the state signal when Timer-6 times up and the signals input to the input ports A, B, and C; On the other hand, in the latter case, Time
The status signal when r-5, Timer-7, and Timer-8 time-lapse, and the input capo-1-A
,B.

The logic is determined by the signal input to C.

In the timing diagram of FIG. 8), the timing at which the paper jam logic determination circuit JAML makes the logic determination is as follows.
Regarding the front edge of the copy paper, F t+, F t2. P
h, Rt+, Rt7 for the trailing edge of the copy paper. Rh, and the detector trigger 9- at each timing.
- I, A-9--2, 4-3 respectively detect whether the leading edge of copy paper has passed (copy paper present) or the trailing edge has passed (copy paper not present). .

■ and ■, 0. In both cases, the copy paper is being conveyed normally without any paper jams.

On the other hand, at timing (3), even though the transfer mechanism is operating and performing a transfer operation, the Kusunoki detector 4 (Q-) does not detect that the leading edge of the copy paper has passed; Even though the transfer mechanism has completed the transfer operation in step (3), if the detector Kariya I does not detect the passage of the trailing edge of the copy paper, the indicates that a paper jam has occurred. Further, in the case where the separation claw 15 operates at timing (3) and the time set in Timer-4 has elapsed, the detector 2 does not detect the passing of the leading edge of the copy paper, and Even though the time corresponding to Timer-7 has passed since the transfer mechanism completed the transfer operation, if the detector 1-2 does not detect the passage of the trailing edge of the copy paper, In both cases, the position P,
Indicates that a paper jam has occurred near the upstream position. Furthermore, at timing O, even though the separation claw 15 is activated and the time set to Timer -4+Timer -6 has elapsed, the detector ±3.
If Timer-7 does not detect the passage of the leading edge of the copy paper and after the transfer mechanism completes the transfer operation,
+T imar -8 If the detector 3 does not detect the passing of the trailing edge of the copy paper even though the time set in -8 has elapsed, in any case, a position upstream near the position P3 is detected. indicates that a paper jam has occurred, and step Q
As shown in FIG.
From 1F to output boats B and C, a pulse train signal for driving the solenoid SOL of the paper jam indicator, and a paper jam indicator lamp E
1. A lighting signal is output.

Note that even when copying on copy paper of various sizes on the copying machine, the timer TM (the first
and second timers TM, TM2), and paper jam detection for each copy sheet can be performed.

2. It seems clear from what I have explained (Mi,
According to the present invention, the detection state of the detection means for detecting the presence or absence of copy paper installed at the paper jam detection position of the second copy paper transport path is
This is determined by the time-up of a presettable digital timer that is set to time-up at the timing when the front and rear edges of the copy paper pass the above-mentioned detection position,
When the time of the first timer means has expired, the detection means has not detected any copy paper, or when the time of the second timer has expired, the detection means has detected the copy paper. Since it is determined that a paper jam has occurred, even if a paper jam occurs at the detection position, the detection means activated when the second timer means times out detects the presence of copy paper and detects the paper jam. Paper jams can be detected quickly and reliably with no detection delay, and the timer value can be easily changed by simply changing the preset value according to the copy paper size, making it easy to detect paper jams at the trailing edge. Moreover, since the counting pulse signal, which is the reference time of the digital timer, is generated in accordance with the driving speed, the timer time-up timing can be adjusted in response to changes in the copy paper conveyance speed. This has an extremely useful effect in practical use, as it allows extremely accurate paper jam detection.

[Brief explanation of drawings]

Fig. 1 is a structural explanatory diagram of an electrophotographic copying machine to which the present invention can be applied, Fig. 2 is a structural explanatory block diagram of a digital timer to which the present invention can be applied, and Fig. 3 shows another embodiment of the digital timer. FIG. 1 is an electric circuit diagram of an embodiment of the copy paper detection means applicable to the present invention, and FIG. An explanatory diagram showing an example set up,
FIG. 6 is a block diagram for explaining the configuration of a digital control device according to an embodiment of the present invention, FIG. 7 is a control flowchart showing an embodiment of the operation of the present invention, and FIG. 8 is a time chart thereof. Co-2, Construction period-3... Copy paper detector, PG, PG2...
...Pulse generator, CP tJ, Micro Central Processing Unit l-1I10TF...Input/output interface circuit, TCC timing control section,
TM...Digital timer, TPL...Copy paper transport path.

Claims (1)

[Claims] (1) A means for generating a predetermined pulse signal, a plurality of counter means for counting up and outputting a control signal when a pulse signal corresponding to preset numerical data is counted, and a sequence control timing for the counter means. means for presetting the numerical data so that a control signal is output in accordance with the size of the recording paper to be used; and means for identifying the size of the recording paper to be used; A means for changing numerical data preset in at least one counter of the counter means, and a means for generating a reference signal in accordance with the operation of a copying machine, etc.; At least one counting operation is started in response to the generation of the reference signal, and sequence control is executed by sequentially starting the plurality of counter means in accordance with the operation sequence of a copying machine, etc., and corresponding to the size of the recording paper. A copying machine characterized in that control related to the trailing edge of a recording sheet is performed using a count-up signal output from a series of counters including counter means for changing numerical data preset by a counter means. Control device in etc.