JP3200121B2 - Electrophotographic process control equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic process control device for controlling various parts of an electrophotographic process in an image forming apparatus such as a copying machine, a printer, a facsimile, etc., which performs copying or printing by an electrophotographic process mechanism. .

[0002]

2. Description of the Related Art In an image forming apparatus in which copying or printing is performed by an electrophotographic process mechanism, a control method in a conventional electrophotographic process includes a surface potential meter on a photosensitive drum, a toner adhesion amount, and the like. A method of performing control by measuring with a photosensor or the like and referring to a toner supply amount, a development bias operation amount, or the like corresponding to each measured value from a table created in advance through experiments or the like, Implementing a method of performing control by finding the optimal amount of operation using a method such as PID control by feeding back the state of the device with a sensor or the like while changing the amount of operation, and implementing an arithmetic unit that performs fuzzy inference Proposed a method of operating each controlled object based on comprehensive judgment from a large number of state parameters intertwined in a variety of ways. To have.

[0003]

However, any of the conventional methods specializes the characteristics of the photosensitive member at the time of control to a certain state (or one of several representative states). The control is performed without grasping the change in the characteristics of the photoconductor.
That is, in a state other than the state in which the photoconductor exhibits the assumed characteristics, there is no guarantee that the optimal control is performed. The causes of the change in the characteristics of the photoreceptor include the following. (1) Change in thickness of photoreceptor. Abrasion caused by contact between the photoconductor and other parts, such as cleaning, changes the electrostatic capacity of the photoconductor and increases the apparent sensitivity. (2) Charging fatigue. A phenomenon in which the sensitivity of the photoreceptor to electrical charging / discharging decreases due to repeated charging / discharging. That is, the charging potential is reduced by making the charging difficult, and the residual potential is raised by making the charging difficult. (3) Exposure fatigue. A phenomenon in which the sensitivity of the photoreceptor to exposure decreases when exposure is repeated. The dynamic range of the electrostatic latent image with respect to the exposure amount is narrowed.

The above (1) is an irreversible characteristic change (irrecoverable), but the characteristics (2) and (3) recover to some extent by being left in the dark. In other words, the degree of fatigue greatly depends on the history of charging, static elimination, and exposure in the past, and it is very difficult to grasp. Further, environmental factors such as temperature and humidity also cause changes in the characteristics of the photoconductor. As described above, since parameters including a time element (history) are complicatedly and variously related to each other, it is not realistic to describe, for example, a charging exposure characteristic of a photoreceptor using a physical expression or the like. Even if it can be described, it is impossible to actually perform the control because the history information of the charge / discharge and the exposure is required when actually used for control.

In order to obtain the charge exposure characteristic of the photoreceptor, it is effective to repeatedly form an electrostatic latent image on the photoreceptor with a reference pattern and measure the surface potential. Has the following restrictions. To measure the surface potential of the electrostatic latent image on the photoconductor drum, a reference pattern is exposed on the photoconductor drum, and the light potential and the dark portion (some halftone portions if necessary) are exposed to the surface potential. Is measured. However, if a latent image is generated on the photoconductor drum, it is inevitably developed (toner adheres to the photoconductor drum). A heavy burden is imposed, and cleaning may not be possible in some cases. Further, the toner is wasted. Actually, since the reference pattern cannot be transferred to the paper, the number of times of measuring the surface potential on the photosensitive drum needs to be minimized in order to protect the cleaning unit. In addition, it takes time to perform the measurement because it goes through a charging-exposure-development-cleaning process. Repetitive measurement reduces the performance of the apparatus itself (reduction in copy / print speed per time, first copy /
Increase the time to print output, etc.).

The present invention has been made in view of the above circumstances, and solves the above-mentioned conventional problems by using a photoconductor characteristic change parameter generating means using a neural network in an electrophotographic process.
An object of the present invention is to provide an electrophotographic process control device capable of realizing a copying machine, a printer, a facsimile, etc., which performs optimal control of each section and outputs higher quality images.

[0007]

According to a first aspect of the present invention, there is provided an electrophotographic process control apparatus, comprising :
Parameters representing an internal / external status of the device obtained from the meter measuring means, the charge amount, the exposure amount, less of the thickness of the photosensitive member
And a parameter representing the potential state of the electrostatic latent image (for example, the potential of the charging unit and the potential of the exposing unit) obtained in advance through experiments as a teacher value, which is a reference for the system of the charging-exposure part of the apparatus. Characteristics, exposure characteristics (eg, environment, charge amount,
The relationship between the input of each parameter such as the exposure amount and the thickness of the photoreceptor and the relationship between the potential of the charged portion and the potential of the exposed portion of the electrostatic latent image actually created on the photoreceptor having the reference characteristics. Means for estimating the potential state of the electrostatic latent image using a neural network, and calculating the output from the means for estimating the potential state of the electrostatic latent image and the actual potential state obtained from the measuring means. A photoconductor characteristic parameter generation unit having a calculation unit that outputs a characteristic parameter of the photoconductor is provided.

[0008] In the electrophotographic process control device according to claim 2, wherein in addition to the configuration of claim 1, the parameter representing the internal / external status of the device obtained from the meter measuring means, the charge amount, at least one of exposure bract, the output from the photoreceptor characteristic parameter generating unit inputs the photoreceptor characteristic parameters, the photoreceptor characteristics operation value for outputting an operation value of each part of the device by switching the plurality of predetermined control operation value table by the parameter It characterized by having a production hand stage.

[0009] In the electrophotographic process control device according to claim 3, wherein in addition to the configuration of claim 1, the parameter representing the internal / external status of the device obtained from the meter measuring means, the charge amount, at least one of exposure bract inputs the photoreceptor characteristic parameter outputted from said photoreceptor characteristic parameter generating means, characterized by having a means to output the optimum operating value of each part of the device by performing fuzzy reasoning.

[0010] In the electrophotographic process control device according to claim 4, wherein in addition to the configuration of claim 1, the parameter representing the internal / external status of the device obtained from the meter measuring means, the charge amount, at least one of exposure First, the photosensitive member characteristic parameter output from the photosensitive member characteristic parameter generating means is input, and the optimal operation value of each unit of the apparatus is output by a neural network in which the optimal operation value has been learned in advance.
It is characterized by having a step .

[0011]

According to the electrophotographic process control device of the present invention,
The provision of the photoreceptor characteristic parameter generation means makes it possible to parameterize the charge exposure characteristic of the photoreceptor and incorporate it into the control. As a result, compared to the conventional control method, a finer granularity adapted to each case can be obtained. In addition, it is possible to control the surface potential optimally. In addition, the variation in the characteristics of the photoconductor reduces the control accuracy. However, according to the present invention, the variation in the characteristics is corrected and absorbed by obtaining a parameter representing the characteristics of the photoconductor by the photoconductor characteristic parameter generation unit. It is possible to perform more accurate control. Further, since the photoconductor characteristic parameter generation means includes the neural network, the function of generating the photoconductor characteristic parameter can be realized with less experiments by the generalization ability of the neural network.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a view showing one embodiment of the first aspect, and is a view showing a basic configuration of a photoconductor characteristic parameter generating apparatus used in an electrophotographic process control apparatus of the present invention. First, the basic configuration of the present apparatus will be described. In FIG. 1, a photoconductor characteristic parameter generation device sends an input value from a measuring unit such as a sensor to a neural network 3 and a photoconductor characteristic parameter generation unit 2 in response to a request from a control unit 4.
A photoreceptor characteristic parameter generation unit 2 for generating photoreceptor characteristic parameters (charging characteristic parameter and exposure characteristic parameter) from a photoreceptor reference potential parameter generated by the network 3 and a potential parameter sent from the input management unit 1; , A control unit 4 for processing an external request and controlling the input management unit 1, the neural network 3, and the photoconductor characteristic parameter generation unit 2.

The neural network 3 includes a photosensitive member film thickness, a charge amount (charger, grid potential, etc.), an exposure amount for forming a pattern for measuring a surface potential, a temperature,
This parameter is obtained when parameters such as the internal / external state of the apparatus such as humidity are input and the surface potential of a reference pattern created with the same charge amount and exposure amount on a photosensitive drum having reference characteristics is measured. The potential of the charged portion and the potential of the exposed portion are output as a charged portion reference potential parameter and an exposed portion reference potential parameter. This neural network 3
Is used as a teacher value for a charged portion potential and an exposed portion potential obtained by experiments using a photosensitive drum having characteristics as a reference in advance (for example, a new photosensitive drum), and learning is performed by a method described later. Shall be left.

Next, the operation of the photoconductor characteristic parameter generating device having the configuration shown in FIG. 1 will be described. In FIG.
The input management unit 1 receives a signal from the control unit 4
Values taken by measuring means such as sensors (electric potential of charged part,
The exposure unit potential, the voltage applied to the grid of the charging charger, the laser diode or exposure lamp voltage for exposure, temperature, humidity, etc.) are converted into parameters that can be input to the neural network 3 and the photoconductor characteristic parameter generation unit 2. . For this conversion, for example, an analog signal is converted into a digital signal (A / D conversion), normalization is performed to secure a dynamic range at the input, and a characteristic parameter is extracted from an input value from a sensor. It includes things to do. In addition, a film thickness parameter of the photoconductor is generated from the total number of rotations of the photoconductor drum in this portion. The photoconductor characteristic parameter generation unit 2 calculates photoconductor characteristic parameters (charging characteristic parameter and exposure characteristic parameter) from the photoconductor reference potential parameter generated by the neural network 3 and the potential parameter sent from the input management unit 1. Generate and output.

FIG. 3 shows an embodiment of the photoreceptor characteristic parameter generation unit 2. In FIG. 3, the photoconductor characteristic parameter generation unit 2 includes a charging characteristic parameter calculation unit 5 and an exposure characteristic parameter calculation unit 6. The charging characteristic parameter calculation unit 5 calculates a charging characteristic parameter from the charging unit reference potential parameter output from the neural network 3 and the charging unit potential parameter sent from the input management unit 1. As this calculation, for example, as the simplest method, a method in which the difference between the charging unit reference potential parameter and the charging unit potential parameter is used as the charging characteristic parameter is considered.
This is nothing but outputting the difference in the characteristic at the potential level between the reference photoconductor (the photoconductor from which the teacher data is collected during learning of the neural network) and the target photoconductor. Similarly, the exposure characteristic parameter calculation unit 6 calculates the exposure characteristic parameter from the exposure unit reference potential parameter output from the neural network 3 and the exposure unit potential parameter sent from the input management unit 1. The control unit 4 is an image forming apparatus (copier, copier, etc.) in which the electrophotographic process control device of the present invention is incorporated.
(A printer, a facsimile, etc.), and controls each unit so that input, calculation, and output of each unit of the control device are performed at appropriate timing by monitoring the electrophotographic process.

FIG. 2 shows an embodiment of a neural network for generating a photoconductor reference potential parameter. (1) Operation in copier / printer. 1 and 2, the neural network 3
In response to a request from the control unit 4, the photoconductor film thickness, charge amount (charging charger, grid applied potential, etc.) sent from the input management unit 1, exposure amount for forming a surface potential measurement pattern, temperature, humidity, etc. This parameter is obtained when the parameters such as the internal / external state of the device are input and the surface potential of a reference pattern created with the same charge amount and exposure amount on a photosensitive drum having reference characteristics is measured. The brazing charger potential and the exposed part potential are output as a charged part reference potential parameter and an exposed part reference potential parameter, and sent to the photoconductor characteristic parameter generator 2.

(2) Learning operation. The neural network 3 includes an environmental factor (temperature, humidity, etc.) and a charge amount (charged charger, grid applied potential, etc.) sent from the input management unit 1 and an exposure amount (exposure amount) for forming a pattern for surface potential measurement. Laser diode or exposure lamp voltage) and photoreceptor film thickness parameters are input, and the electrostatic latent image pattern is formed on a photoreceptor drum (for example, a new photoreceptor drum) having a reference characteristic while changing the input. After that, learning is performed by receiving the charging unit potential parameter and the exposure unit potential parameter from the input management unit 1 as teacher values. This makes it possible to learn the relationship between the environment, the charge amount, the exposure amount, the photoconductor film thickness, the charged portion potential, and the exposed portion potential in the photosensitive drum having the reference characteristics.

Next, embodiments of the second, third and fourth aspects will be described. FIG. 4 is a diagram showing one embodiment of claims 2, 3 and 4, and is a diagram showing a basic configuration of an electrophotographic process control device. First, the basic configuration of the present apparatus will be described. The electrophotographic process control device according to the present embodiment includes a photoconductor characteristic parameter generation device 11 and a photoconductor characteristic parameter generation device 11 described in claim 1.
Charger control unit 12 that generates an operation value of the charger by using the charging characteristic parameter generated by the above and various parameters obtained from the sensor and the like, and the exposure characteristic parameter and sensor generated by the photoconductor characteristic parameter generation device 11 And an exposure unit control unit 13 for generating an operation value of the exposure unit by using various parameters obtained from the above-mentioned operations. It should be noted that the second, third and fourth aspects differ only in the configuration of the charger controller 12 and the exposure controller 13.

Next, the operation of the electrophotographic process control device shown in FIG. 4 will be described. In FIG. 4, a photoconductor characteristic parameter generating device 11 performs the operation described in the first embodiment while communicating with a central processing unit via an internal bus of the device, and outputs photoconductor characteristic parameters. The charger control unit 12 generates an operation value of the charger using the charging characteristic parameters generated by the photoconductor characteristic parameter generation device 11 and various parameters obtained from sensors and the like,
Send to charger drive section. The exposure unit control unit 13 generates an operation value of the exposure unit using the exposure characteristic parameter generated by the photoconductor characteristic parameter generation unit 11 and various parameters obtained from the sensors and the like, and sends the operation value to the exposure unit driving unit.

FIG. 5 shows an embodiment of the charger controller 12 (or the exposure controller 13) of the electrophotographic process controller according to the second aspect. The charger control unit 12 (hereinafter, the same also when read as the exposure unit control unit 13) uses a plurality of photoconductors having different characteristics and conducts experiments and the like in advance by a method similar to the conventional control method by referring to a table. Have multiple operation value tables created. This operation value table is
For example, it is assumed that the matrix structure has the same dimension as the number of parameters sent from a sensor, an operation panel, a scanner, or the like, and an optimum operation value is written in each element. Then, at the time of outputting the operation value, the operation value table selecting unit first has the characteristic closest to the current photoconductor characteristic by the photoconductor characteristic parameter (charging characteristic parameter (exposure characteristic parameter in the case of the exposure unit control unit 13)). Select an operation value table created by the photoconductor. Next, a table lookup operation is performed for each parameter using the selected operation value table to determine an operation value. Then, the determined operation value is sent to each element drive unit.

Next, FIG. 6 shows the charger controller 12 (or the exposure controller 1) of the electrophotographic process controller according to claim 3.
An example of 3) will be described. The charger control unit 12 (hereinafter, the same also when read as the exposure unit control unit 13) previously incorporates, as rules, related information included in the copier control system with a change in the characteristics of the photoconductor. It is composed of a fuzzy arithmetic unit. At the time of outputting the operation value, the photosensitive member characteristic parameter (charging characteristic parameter (exposure characteristic parameter in the case of the exposure unit control unit 13)) and each parameter sent from the sensor, the operation panel, the scanner, and the like are used as the membership function. This is treated as ambiguous information by replacement, and an operation value is determined by performing a fuzzy operation according to a built-in rule. Then, the determined operation value is sent to each element drive unit.

Next, FIG. 7 shows the charger controller 12 (or the exposure controller 1) of the electrophotographic process controller according to claim 4.
An example of 3) will be described. The charger control unit 12 (hereinafter the same as reading unit control unit 13) uses a plurality of photoconductors having different characteristics and changes each parameter sent from a sensor, an operation panel, a scanner, or the like. It is configured by a neural network that has learned while using the optimal operation values obtained in advance through experiments and the like as teacher values. At the time of outputting the operation value, the photoconductor characteristic parameter (charging characteristic parameter (exposure characteristic parameter in the case of the exposure unit control unit 13)) and each parameter sent from the sensor, the operation panel, the scanner, etc. As an input, an operation value is determined by causing a neural network to estimate an optimum operation value.
Then, the determined operation value is sent to each element drive unit.

[0023]

Although the embodiments have been described above, the electrophotographic process control apparatus of the present invention has the following effects. (1) Reliable acquisition of device status information. The provision of the photoreceptor characteristic parameter generation means makes it possible to parameterize the charge exposure characteristic of the photoreceptor and incorporate it into the control. As a result, compared to the conventional control method, a finer granularity adapted to each case can be obtained. In addition, it is possible to control the surface potential optimally. For example, in the conventional control method, it was not expected that optimal control would be performed on a photosensitive drum that was extremely deteriorated (the sensitivity was reduced = characteristics were shifted from the photosensitive drum to be controlled). It is expected that more accurate control can be performed by obtaining a parameter representing a characteristic change.

(2) Prevention of deterioration in control accuracy due to variations in the characteristics of the photosensitive member in manufacturing. Variations in photoreceptor characteristics reduce control accuracy,
According to the present invention, it is possible to correct and absorb the variation in the characteristics by obtaining the parameters representing the characteristics of the photoconductor by the photoconductor characteristic parameter generating means, and it is possible to expect more accurate control.

(3) Reduction of development period and cost. Since the photoreceptor characteristic parameter generation means has a neural network, the function of generating the photoreceptor characteristic parameter can be realized with less experiments due to the generalization ability of the neural network. In other words, for each parameter of environmental factors (temperature, humidity, etc.), the amount of charge (charged charger, grid applied potential, etc.) and the amount of exposure (laser diode or exposure lamp voltage) for pattern formation for surface potential measurement, This means that functions can be realized with fewer combinations. This means that if the same function is to be realized by a table reference method, experiments must be performed for every combination of each parameter (a huge number of experiments). ), Compared to having to keep a huge amount of tables in the device,
The development time and cost are greatly reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of claim 1, and is an explanatory diagram showing a basic configuration of a photoconductor characteristic parameter generation device used in an electrophotographic process control device.

FIG. 2 is an explanatory diagram showing an embodiment of a neural network for generating a photoconductor reference potential parameter of the photoconductor characteristic parameter generation device shown in FIG. 1;

FIG. 3 is an explanatory diagram showing an embodiment of a photoconductor characteristic parameter generation unit 2 of the photoconductor characteristic parameter generation device shown in FIG. 1;

FIG. 4 is a diagram showing one embodiment of claims 2, 3 and 4, and is an explanatory diagram showing a basic configuration of an electrophotographic process control device.

FIG. 5 is an explanatory view showing an embodiment of the charger control unit 12 (or the exposure unit control unit 13) of the electrophotographic process control device according to claim 2;

FIG. 6 is an explanatory view showing an embodiment of the charger controller 12 (or the exposure controller 13) of the electrophotographic process control device according to claim 3;

FIG. 7 is an explanatory view showing an embodiment of the charger controller 12 (or the exposure controller 13) of the electrophotographic process control device according to claim 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Input management part 2 ... Photoconductor characteristic parameter generation part 3 ... Neural network 4 ... Control part 5 ... Charging characteristic parameter calculation part 6 ... Exposure characteristic parameter calculation part 11. ..Photoreceptor characteristic parameter generation device 12: charger control unit 13: exposure unit control unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G03G 15/00 303 G03G 21/00 370-540

Claims (4)

(57) [Claims] A surface of at least a photosensitive member as an electrostatic latent image carrier
Surface potential, temperature, and measuring means for measuring the humidity in the image forming apparatus having an electrophotographic process mechanism, the interior of an electrophotographic process control device for controlling the electrophotographic process, obtained from the above SL measuring means device / Small of parameters representing the external state , charge amount , exposure amount , and photoconductor film thickness
At least one of the inputs is used as input, and the parameters representing the potential state of the electrostatic latent image obtained in advance through experiments are used as teacher values to learn the charging characteristics and exposure characteristics that are used as references for the system of the charging-exposing portion of the apparatus. Using the neural network we put,
Means for estimating the potential state of the electrostatic latent image, and calculating the output from the means for estimating the potential state of the electrostatic latent image and the actual potential state obtained from the measuring means, thereby calculating the characteristic parameters of the photoreceptor. An electrophotographic process control device, comprising: a calculation unit that outputs the following; and a photoconductor characteristic parameter generation unit that includes: 2. An electrophotographic process control device according to claim 1.
, At least one of a parameter representing an internal / external state of the device obtained by the measuring means , a charge amount , and an exposure amount
When, the output from the photoreceptor characteristic parameter generating unit inputs the photoreceptor characteristic parameters, the photoreceptor characteristics operation value for outputting an operation value of each part of the device by switching the plurality of predetermined control operation value table by the parameter electrophotographic process control apparatus characterized by having a production hand stage. 3. An electrophotographic process control apparatus according to claim 1.
, At least one of a parameter representing an internal / external state of the device obtained by the measuring means , a charge amount , and an exposure amount
When the hand stage as input photoreceptor characteristic parameter outputted from said photoreceptor characteristic parameter generating means, and outputs the optimum operating value of each part of the device by performing a fuzzy operation
Electrophotographic process control apparatus characterized by having a. 4. An electrophotographic process control device according to claim 1.
, At least one of a parameter representing an internal / external state of the device obtained by the measuring means , a charge amount , and an exposure amount
When, to have a hand stage the photoreceptor characteristic parameter outputted from the photoreceptor characteristic parameter generating means, and outputs an optimum operation value of each part of the device by trained neural network in advance optimum operation value An electrophotographic process control device.