JPH05127474A - Image forming device - Google Patents

Abstract

PURPOSE:To use a control mechanism, which controls concentration setting operations, in common. CONSTITUTION:A toner concentration control part 201 decides the attached/ detached state of a volume substrate 1. When deciding that the volume substrate 1 is attached, the toner concentration control part 201 determines to use a first concentration specifying means as the specification of the concentration with respect to a printer engine; when deciding that the volume substrate 1 is not attached, the toner concentration control part 201 decides to use an image controller as the specification of the concentration with respect to the printer engine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for developing an electrostatic latent image formed by an electrophotographic process with a developer to form an image, and more particularly to a high voltage supplied by a high voltage power source. The present invention relates to an image forming apparatus capable of controlling and adjusting an image density.

[0002]

2. Description of the Related Art FIG. 8 is a circuit block diagram showing an example of a developing density adjusting circuit in a conventional image forming apparatus.
Is an engine control unit for controlling the high-voltage power output to the photoconductor, 101 is a volume resistor, and by changing the resistance value of the volume resistor 101, a high-voltage DC output PrDC and The high voltage DC output DevDC that determines the development potential can be adjusted. Reference numeral 200 is an A / D converter, which is a volume resistor 101.
The set potential is converted into a digital signal (density setting data) and output to the toner density control unit 201. The toner density control unit 201 corrects and converts the density setting data into a predetermined value, outputs the correction value to the D / A converter 202, and outputs the correction potential from the D / A output of the engine control unit 100 to the resistor 102. It is configured to be set. In addition to the above, as the high-voltage power supply output, there is a transfer high-voltage output or a high-voltage AC output superimposed on the high-voltage DC output PriDC depending on the system process form, but they are omitted here.

In the engine control unit 100, OSC is the high voltage DC output PriDC and the high voltage DC output DevDC.
Is a pulse output to the transistors 109 and 129 that drive the transformers 118 and 130 that output. HV1 is an ON / OFF signal of the high voltage DC output PriDC, and HV2 is an ON / OFF signal of the high voltage DC output DevDC.

High-voltage DC output PriDC, high-voltage DC output D
evDC is determined by the emitter potentials of the transistors 116 and 145, that is, the outputs of the operational amplifiers 113 and 140, respectively. Further, the operational amplifiers 113 and 14
The output of 0 is the volume resistor 101 and the resistors 102, 1
04 and 105 and the configuration of the power supply voltage VCC. That is, it is determined by the open loop gain by the voltage to the inverting input of the operational amplifier 113, 140 and the differential voltage to the non-inverting input. Here, operational amplifiers 113 and 1
Since the voltage to the inverting input and the non-inverting input of 40 is almost equal, the high voltage DC output PriDC is a current ipri that results from the difference between the input voltage to the inverting input and the voltage obtained by dividing the power supply voltage VCC by the resistors 122 and 123. Is determined by the voltage drop across the resistor 126. The same applies to the high-voltage DC output DevDC.

112, 115, 120, 133, 13
7, 141 are capacitors, 114, 117, 119, 1
31, 132, 146 are diodes, 103, 106,
107, 108, 110, 111, 121, 124, 1
27, 128, 134, 135, 136, 138, 13
Reference numerals 9, 142 and 144 are resistors, and 125 and 143 are transistors.

The developing density adjusting operation by the volume resistor 101 will be described below with reference to FIG.

FIG. 9 shows the volume resistor 1 shown in FIG.
FIG. 10 is a diagram showing the relationship between the development density adjustment by 01 and the adjustment potential, where the vertical axis represents the potential, the horizontal axis represents the adjustment level F,
F1 corresponds to the GND potential, F5 corresponds to VCC / 2, and F9 corresponds to VCC.

As shown in this figure, the high voltage DC output Pri
High voltage DC output DevDC for determining DC and development potential
The adjustment level F is displaced each time the user operates the density setting volume with the operation unit, and is linearly varied according to this displacement, and it is possible to adjust the printed image from a dark state to a light state. There is. The characteristics shown in FIG. 9 are obtained when the electrophotographic process is image exposure.

Next, an example in which an image controller that converts code information into dot data based on code information from the outside issues a density instruction to the engine control unit 100 will be described.

An image controller (not shown) may need to specify the density of an image depending on the contents currently developed and other conditions. For example, if the image currently being developed is an image of Chinese characters and there are relatively many thin lines, it is better to reduce the density, and if it is an image with many relatively thick lines such as alphabets, the density is It may be better to make the darker. That is, there is a case where the density for forming an image is changed by either the image forming apparatus dedicated to European text or the image forming apparatus dedicated to Japanese. Further, even if the engine control unit 100 is not provided with a density adjusting volume, the density is set by inputting the density value from the operation panel connected to the image controller, and when the cost is reduced, the image controller is operated by the engine. It is necessary to transfer the density data to the control unit 100. The laser beam in this case will be described with reference to FIG.

FIG. 10 is a circuit block diagram showing another example of the developing density adjusting circuit according to this type of image forming apparatus, which is proposed in Japanese Patent Application No. 2-196127 and is the same as FIG. Are given the same reference numerals.

The density information sent from the image controller is transferred to the toner density control unit 201, where the density information is corrected and converted into a predetermined value, and the D / A output of the engine control unit 100 is transferred to the resistor 102. The correction potential is set. Since the other circuits are the same as the circuits described above, description thereof will be omitted.

Each of these two types of density correction processing has its own characteristics and is used according to the intended use. recently,
The latter means as shown in FIG. 10 is often adopted because it is possible to make fine settings according to the state and the cost is low.

[0014]

However, when confirming the function of the engine without the image controller installed, the image density cannot be changed. Further, a different engine control unit 1 is used as a model for changing the density by volume as shown in FIG. 8 and a model for changing the density based on an instruction from the image controller as shown in FIG.
There was a problem that we had to make 00.

The present invention has been made in order to solve the above-mentioned problems, and the density setting processing is performed by automatically determining the density setting subject by judging the connection state of the density designating means of the image forming apparatus main body. An object is to obtain an image forming apparatus that can share a control mechanism for controlling.

[0016]

An image forming apparatus according to the present invention includes a removable first density designating unit for designating an image density to be set in a printer engine from the outside, and an image density set in a printer engine. The second density designating means for designating the image density based on the density information input from the image controller, the determining means for determining the attachment / detachment state of the first density designating means, and the first based on the determination result by the determining means. The density designating means or the second density designating means is provided with a determining means for determining a density designation destination.

[0017]

According to the present invention, the determining means determines the attachment / detachment state of the first density designating means, and when it is determined that the first density designating means is installed, the determining means determines the density designation destination for the printer engine. As the first concentration designating means,
When it is determined that the first density designating means is not installed, the determining means determines the density designation destination for the printer engine to be the second density designating means, and the first density designating means or the second density designating means. It is possible to drive and control the system capable of deciding the density designation destination to any one of the above and the system performing the density designation by only one of the density designation means by the same engine control unit.

[0018]

【Example】

[First Embodiment] FIG. 1 is a block diagram for explaining the arrangement of an image forming apparatus according to the first embodiment of the present invention.

In the figure, 100 is an engine control unit,
A density information signal 8 from an image controller (not shown) and a density information line 3 from the volume substrate 1 are connected to the engine control unit 100. The detachable volume substrate 1 has a volume 7 for the user, and the volume 7 is connected to the power supply voltage 2 and the ground 4. The voltage according to the position of the slider of the volume 7 is the concentration information line 3 Is input to the A / D converter 200 through.
The density information from the volume substrate 1 is digitized by this A / D converter 200 and the toner density control unit 201
Sent to. The toner density control unit 201 monitors the volume substrate presence / absence signal 5, and uses the density information signal 8 from the image controller depending on whether the volume substrate presence / absence signal 5 is at a high level or a low level. It is determined whether to use the D-converted data. Volume board presence / absence signal 5 is + 5V in the volume board 1
Therefore, when the volume substrate 1 is connected to the engine control unit 100, the high level (+
5 V), and when there is no volume substrate 1, the pull-down resistor 6 fixes it to a low level (+0 V). As a result, the determined result is D / A converted and output as a correction voltage. The subsequent circuit is the same as the high voltage generating circuit described in the conventional example.

In the image forming apparatus having the above structure, the determining means (toner density control section 201 in this embodiment)
Determines the attachment / detachment state of the first density designating means (volume substrate 1), and when it is determined that the first density designating means is mounted, the determining means determines the density designation destination for the printer engine as the first density. When it is determined that the first density designating means is not installed, the determining means (toner density control unit 201 in this embodiment) determines the density designation destination for the printer engine as the second density designating means. (Image controller), a system capable of determining the density designation destination in either the first density designation means or the second density designation means, and a system which designates the density by only one of the density designation means Drive control can be performed by the same engine control unit 100.

The density setting processing operation will be described below with reference to the flow chart shown in FIG.

FIG. 2 is a flow chart showing an example of the first density setting processing procedure in the image forming apparatus according to the present invention. Note that (1) to (7) indicate each step.

First, in the density setting sequence, the volume substrate presence / absence signal 5 is monitored (1), and the toner density control unit 201 determines whether or not the volume 7 exists (2).
If NO, the density information signal 8 is read (3) and converted into D / A output data (4). On the other hand, when the determination in step (2) is YES (when the volume 7 is present), the analog potential output to the concentration information line 3, that is, the concentration potential set by the volume 7 is set to the A / D converter 200.
A / D converts (5), and D / A is converted according to this digital value.
Convert to data for conversion (6). The D / A output value thus obtained is D / A converted and output, and the correction potential is set in the resistor 102 from the D / A output of the D / A converter 202 of the engine control unit 100. (7), the process ends.

By executing the above processing, the image density can be changed even when the function of the engine is confirmed without the image controller being mounted. Further, the engine control unit 100 of the model for changing the density with the volume 7 and the model for changing the density based on the instruction from the image controller can have the same configuration, and the engine control unit 100 can be generalized. [Second Embodiment] FIG. 3 is a block diagram for explaining the arrangement of an image forming apparatus according to the second embodiment of the present invention. The same parts as those in FIG. 1 are designated by the same reference numerals. The configuration and operation will be described below.

The volume board 20 is composed of one volume 21, and the volume 21 has a power supply line 22,
It is connected to the ground through the resistor 25 through the resistor 24. The slider of the volume 21 is connected to A via line 23.
It is connected to the first channel CH1 of the / D converter 200. The second channel CH2 of the A / D converter 200 monitors the voltage of the power supply line 24. This voltage is “0” V when the volume substrate 20 is not present because it is connected to the ground by the resistor 25. The presence or absence of the volume substrate 20 can be determined by monitoring this voltage. The data from the A / D converter 200 is transferred to the toner density control unit 26. The toner concentration control unit 26 determines the presence or absence of the volume substrate 20 according to the determination method described above, and uses the data of the first channel CH1 of the A / D converter 200, or the concentration from an image controller (not shown). It is determined whether to use the data of the information signal 8. Thereby, the calculated data is transferred to the D / A converter 202, and the correction potential is set and output from the D / A output of the engine control unit 100 to the resistor 102. The subsequent high-voltage generating circuit can be the same as the conventional laser beam, and therefore its description is omitted. The second density setting processing operation will be described below with reference to the flowchart shown in FIG.

FIG. 4 is a flow chart showing an example of the second density setting processing procedure in the image forming apparatus according to the present invention. Note that (1) to (7) indicate each step.

First, when entering the density setting sequence, A /
Monitor the second channel CH2 of the D converter 200 (1)
The toner density control unit 26 determines whether there is the volume 21, that is, whether the A / d conversion value of the second channel CH2 is "0" (2), and if NO, reads the density information signal 8 (3). , Convert to D / A output data
(Four) .

On the other hand, when the determination in step (2) is YES (when the volume 21 is present), the analog potential output to the line 23, that is, the concentration potential set by the volume 21 (value of the first channel CH1). A / D
The converter 200 performs A / D conversion (5), and according to the digital value, converts into D / A conversion data (details are shown in FIG. 5) (6). The D / A output value thus obtained is D / A converted and output, and the D / A value of the engine control unit 100 is output.
The correction potential is set in the resistor 102 from the D / A output of the A converter 202 (7), and the process is terminated. In FIG. 5, the vertical axis represents the data after A / D conversion, and the horizontal axis represents the sliding rate of the volume 21.

By executing the above processing, the image density can be changed even when the function of the engine is confirmed in the state where the image controller is not mounted. Further, the engine control unit 100 of the model for changing the density with the volume 21 and the model for changing the density based on the instruction from the image controller can have the same configuration, and the engine control unit 100 can be generalized. Further, the number of wires between the engine control unit 100 and the volume board 20 is only three. [Third Embodiment] FIG. 6 is a block diagram for explaining the arrangement of an image forming apparatus according to the third embodiment of the present invention. The same parts as those in FIG. 1 are designated by the same reference numerals. The configuration and operation will be described below.

The volume substrate 30 comprises one volume 21 and one resistor 31, and the volume 21
Is connected to the ground through the power supply lines 22 and 24 and the resistor 32. The resistor 31 has a volume 21
"0" V is applied to the slider even if the slider is moved to a lower voltage
Is to prevent it from being output. The slider of the volume 21 is connected to the A / D converter 2 via the line 33.
00 is connected. This voltage is applied to the volume substrate 3
If 0 is not present, it is "0" V because it is connected to ground by resistor 31. It is necessary to set the resistance value of the resistor 31 to be considerably larger than that of the volume 21. If this is not done, the input voltage from the volume substrate 30 will not be in a proportional relationship with the movement of the slider.

The presence or absence of the volume substrate 30 can be determined by monitoring this voltage. This A /
The data from the D converter 200 is used as the toner density control unit 26.
Transferred to. The toner density control unit 26 determines the presence / absence of the volume substrate 30 by the above-described determination method, and the A / D
It is decided whether to use the data of the converter 200 or the data of the density information signal 8 from the image controller (not shown). As a result, the calculated data is transferred to the D / A converter 202 and the engine control unit 10
The correction potential is set and output from the D / A output of 0 to the resistor 102. The subsequent high-voltage generating circuit can be the same as the conventional laser beam, and therefore its description is omitted. Hereinafter, the third density setting processing operation will be described with reference to the flowchart shown in FIG.

FIG. 7 is a flow chart showing an example of a third density setting processing procedure in the image forming apparatus according to the present invention. Note that (1) to (7) indicate each step.

First, when entering the density setting sequence, A /
Monitor the voltage of D converter 200 (1), and adjust the volume 21
Whether there is, that is, the A / D of the A / D converter 200
The toner density control unit 26 determines whether the converted value is "0" (2). If NO, the density information signal 8 is read (3), D
Convert to / A output data (4).

On the other hand, when the determination in step (2) is YES (when the volume 21 is present), the A / D converter 200 outputs the analog potential output to the line 33, that is, the concentration potential set by the volume 21. A / D conversion
(5) The data is converted into D / A conversion data (details are shown in FIG. 5) according to the digital value (6). The D / A output value thus obtained is D / A converted and output, and the correction potential is set in the resistor 102 from the D / A output of the D / A converter 202 of the engine control unit 100 ( 7) Then, the processing ends.

By executing the above processing, the image density can be changed even when the function of the engine is confirmed in the state where the image controller is not mounted. Further, the engine control unit of the model for changing the density with the volume and the model for changing the density based on the instruction from the image controller can have the same configuration, and the engine control unit can be generalized. Further, the A / D converter 200 has only one channel. Further, in the present embodiment, the density adjustment by the high pressure control is described as an example, but it is also possible to apply the setting by the volume like the laser power.

[0036]

As described above, according to the present invention, when the judging means judges the attachment / detachment state of the first density specifying means, and when it is judged that the first density specifying means is attached, the determining means When the density designation destination for the printer engine is determined to be the first density designation means and it is determined that the first density designation means is not mounted, the determination means designates the density designation destination for the printer engine as the second density designation means. Since the image density is configured to be determined in the apparatus, the image density can be changed by mounting the first density designating means even in the state where the image controller is not mounted in the apparatus for designating the density by the image controller. You can check the functionality of the print engine without the controller being implemented.

Further, the circuit configuration of the engine control unit in the apparatus for designating the concentration by the first concentration designating means or the second concentration designating means can be made common, and the same density designating system can be used. The engine control unit can be used, which brings about effects such as cost reduction due to mass production effect and significant reduction of parts management burden.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of an image forming apparatus according to a first exemplary embodiment of the present invention.

FIG. 2 is a flowchart showing an example of a first density setting processing procedure in the image forming apparatus according to the present invention.

FIG. 3 is a block diagram illustrating a configuration of an image forming apparatus showing a second embodiment of the present invention.

FIG. 4 is a flowchart showing an example of a second density setting processing procedure in the image forming apparatus according to the present invention.

FIG. 5 is a characteristic diagram showing the relationship between the data after A / D conversion and the sliding rate of the volume in the image forming apparatus according to the present invention.

FIG. 6 is a block diagram illustrating a configuration of an image forming apparatus according to a third exemplary embodiment of the present invention.

FIG. 7 is a flowchart showing an example of a third density setting processing procedure in the image forming apparatus according to the present invention.

FIG. 8 is a circuit block diagram showing an example of a development density adjustment circuit according to a conventional image forming apparatus.

9 is a diagram showing the relationship between the development density adjustment by the volume resistor shown in FIG. 8 and the adjustment potential.

FIG. 10 is a circuit block diagram showing another example of a development density adjusting circuit according to this type of image forming apparatus.

[Explanation of symbols]

 1 Volume Substrate 2 Power Supply Voltage 3 Concentration Information Line 5 Volume Substrate Presence / Absence Signal 6 Pulldown Resistor 100 Engine Control Unit 200 A / D Converter 201 Toner Density Control Unit 202 D / A Converter

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location H04N 1/29 Z 9186-5C

Claims (1)

[Claims] 1. An image controller unit for analyzing code information input from an external device and converting it into dot data for modulating a light beam, and a light beam modulated based on the dot data on a photoconductor. An image forming apparatus having a printer engine that scans and forms an image to form an image, and an engine control unit that controls image forming conditions of the printer engine, is detachable for externally designating an image density to be set in the printer engine. The first density designating means, the second density designating means for designating the image density to be set in the printer engine based on the density information input from the image controller section, and the attachment / detachment of the first density designating means. A determination unit for determining the state, and the first concentration designation unit or the second concentration designation unit based on the determination result by the determination unit. An image forming apparatus comprising: a determination unit that determines a density designation destination.