JPH08110664A - Electrophotographic process controller - Google Patents

Abstract

PURPOSE: To accurately estimate toner electrostatically charged amount being an important factor in the case of estimating toner adhering amount being one parameter for deciding an image forming condition. CONSTITUTION: This controller is provided with sensor means respectively measuring the surface potential of a photoreceptor, developing bias potential in a developing device and the toner adhering amount on the surface of the photoreceptor, and a developer fatigue degree estimating means 45a simulating relation between developing potential, toner adhering amount and the degree of fatigue of developer by inputting at least one of the output from the respective sensor means, and estimating the degree of the fatigue of the developer. The parameter being the degree of fatigue of the developer is introduced as an index showing the easiness of electrostatic charging of the developer largely participating in the toner electrostatically charged amount, and the degree of fatigue of the developer is estimated by using a simulation model based on relation between the developing potential and the toner adhering amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer, a facsimile, etc. for copying and printing an image by an electrophotographic process mechanism including a developing device for developing an electrostatic latent image formed on a photoconductor. The present invention relates to an electrophotographic process control device for controlling each part of an image forming apparatus.

[0002]

2. Description of the Related Art Generally, in order to obtain a high-quality image in an image forming apparatus such as a copying machine, it is one of the factors of the toner adhesion amount on the photoconductor, and it is necessary to control it. In this respect, as a toner adhesion amount control method in this type of electrophotographic process, conventionally, there are a table reference method and a feedback control method. The table reference method measures the toner adhesion amount on the photoconductor with an image density sensor or the like, and from a table (look-up table) created in advance by experiments or the like, the charge amount (charging amount) that becomes each image forming parameter corresponding to each measurement value. Charger voltage, electrification grid voltage, etc.)
And exposure amount (exposure lamp, exposure laser, exposure LED
Driving voltage of exposure light source, pulse modulation width, etc.) and toner density, etc.
It is disclosed in Japanese Patent Laid-Open No. 5-14729. Also,
The feedback control method is to find an optimum operation amount by using a control method such as PID control by feeding back the device state with a sensor or the like while changing the operation amount of an image forming parameter. Sho 63-151973
It is shown in Japanese Patent Publication No.

[0003]

However, in the former table reference method, the data to be referred to is limited, and it is difficult to accurately grasp and control the characteristics of the photoconductor.

Further, in the latter feedback control method, the feedback loop is repeatedly rotated until the ideal control state is reached, and the charging and exposure processes are performed each time, so that it is wasteful in time and the apparatus itself. Performance (i.e., slower copy or print speed per hour, increased time to first copy or printout). Particularly in the color electrophotographic process, since it is also necessary to control the intermediate density, the time required for the control increases in proportion to the number of intermediate densities to be controlled.

[0005]

According to a first aspect of the invention, an electrophotographic process control for an image forming apparatus having an electrophotographic process mechanism including a developing device for developing an electrostatic latent image formed on a photoconductor is provided. In the apparatus, a sensor means for measuring the surface potential of the photoconductor, a developing bias potential in the developing device, and a toner adhesion amount on the photoconductor surface, and at least one of outputs from the sensor means are input. A developer fatigue degree estimating means for simulating the relationship between the development potential, the toner adhesion amount, and the developer fatigue degree is provided to estimate the fatigue degree of the developer.

According to a second aspect of the invention, in addition to the structure of the first aspect of the invention, a sensor means for measuring the toner concentration in the developing device is also provided, and the developer fatigue degree estimating means also considers this toner concentration to develop. The fatigue level of the developer is estimated by simulating the relationship among the potential, the toner adhesion amount, the toner concentration, and the developer fatigue level.

In the third aspect of the invention, in addition to the configuration of the second aspect of the invention, sensor means for measuring environmental conditions such as temperature and humidity is also provided, and the developer fatigue degree estimating means also considers these environmental conditions. The fatigue level of the developer was estimated by simulating the relationship among the development potential, the toner adhesion amount, the toner concentration, the environmental conditions, and the developer fatigue level.

According to a fourth aspect of the invention, in addition to the structure of the first aspect of the invention, at least one of the output from the sensor means relating to the surface potential and the developing bias potential and the output from the developer fatigue degree estimating means. The toner adhesion amount estimating means for estimating the toner adhesion amount by simulating the relationship among the development potential, the developer fatigue degree, and the toner adhesion amount by inputting is provided.

According to a fifth aspect of the invention, in addition to the configuration of the second aspect of the invention, at least one of the output from the sensor means relating to the surface potential and the developing bias potential and the output from the developer fatigue degree estimating means. The toner adhesion amount estimating means for estimating the toner adhesion amount by simulating the relationship among the development potential, the developer fatigue degree, and the toner adhesion amount by inputting is provided.

According to a sixth aspect of the invention, in addition to the configuration of the second aspect of the invention, the output from the sensor means concerning the surface potential, the developing bias potential and the toner concentration and the output from the developer fatigue degree estimating means are provided. A toner adhesion amount estimating means for estimating the toner adhesion amount by simulating the relationship among the development potential, the toner concentration, the developer fatigue degree, and the toner adhesion amount with at least one input is provided.

According to a seventh aspect of the invention, in addition to the configuration of the second aspect of the invention, a sensor means for measuring environmental conditions such as temperature and humidity is provided, and further, the surface potential from the sensor means, the developing bias potential, At least one of the output relating to the toner concentration and the environmental condition and the output from the developer fatigue degree estimating means is used as an input to simulate the relationship between the development potential, the toner concentration, the environmental condition, the developer fatigue degree, and the toner adhesion amount. A toner adhesion amount estimating means for estimating the toner adhesion amount is provided.

According to an eighth aspect of the invention, in addition to the configuration of the third aspect of the invention, at least one of the output from the sensor means relating to the surface potential and the developing bias potential and the output from the developer fatigue degree estimating means. The toner adhesion amount estimating means for estimating the toner adhesion amount by simulating the relationship among the development potential, the developer fatigue degree, and the toner adhesion amount by inputting is provided.

According to a ninth aspect of the invention, in addition to the configuration of the third aspect of the invention, an output relating to the surface potential, the developing bias potential and the toner concentration from the sensor means and an output from the developer fatigue degree estimating means. A toner adhesion amount estimating means for estimating the toner adhesion amount by simulating the relationship among the development potential, the toner concentration, the developer fatigue degree, and the toner adhesion amount with at least one input is provided.

According to a tenth aspect of the present invention, in addition to the constitution of the third aspect of the invention, the output from the sensor means concerning the surface potential, the developing bias potential, the toner concentration and the environmental condition and the developer fatigue degree estimating means are outputted. A toner adhesion amount estimating means for estimating the toner adhesion amount by simulating the relationship among the development potential, the toner concentration, the environmental condition, the developer fatigue degree, and the toner adhesion amount by using at least one of the output and the output is provided.

[0015]

The amount of toner adhered is influenced by the magnitude of the developing potential and the amount of toner charge. Here, since the toner is charged by frictional charging, the toner charge amount can be estimated if the easiness of charging the developer is known, and thus the toner adhesion amount can be estimated. Conversely, if the toner adhesion amount is known, the toner charge amount can be estimated from parameters such as toner density and humidity that affect the development potential and the toner charge amount.

Therefore, in controlling the toner adhesion amount, it is important to know the toner charge amount. In this respect, according to the first aspect of the invention, the ease of charging of the developer is regarded as a parameter called "developer fatigue degree", and the simulation is performed by the developer fatigue degree estimating means based on the relationship between the development potential and the toner adhesion amount. The developer fatigue level can be accurately estimated by the above. According to the second aspect of the present invention, since the developer fatigue level is estimated in consideration of the toner concentration, it is possible to estimate the developer fatigue level with higher accuracy.
In the invention according to claim 3, the temperature
Since the developer fatigue level is estimated in consideration of environmental conditions such as humidity, it is possible to more accurately estimate the developer fatigue level. By reflecting the highly accurate developer fatigue degree estimated value on the toner charge amount or the toner adhesion amount, it is possible to accurately estimate the toner adhesion amount.

That is, in the present invention as defined in claims 4 to 10, the developer fatigue level estimated by the developer fatigue level estimation means using the simulated model is used as a parameter for estimating the toner charge amount, and the development potential In addition, in consideration of factors such as toner density and environmental conditions, the toner adhesion amount is accurately estimated by simulation by the toner adhesion amount estimation means. From such a highly accurate estimated value of the amount of adhered toner, an appropriate image forming condition for the next image forming can be known, and high quality image forming can be achieved.

In the invention according to any one of claims 1 to 10, it is possible to use a neural network as a simulation model constituting the developer fatigue degree estimating means and the toner adhesion amount estimating means. Due to the generalization ability of, the developer fatigue level and the toner adhesion amount can be estimated with less experiments. That is, the function can be realized with a smaller combination of parameters such as toner density and environmental conditions.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. It is to be noted that, after a general description of the outline of embodiments covering the inventions described in each claim, embodiments corresponding to the inventions described in each claim will be individually described.

<Outline of Embodiments> First, the outline of the configuration of a copying machine as an image forming apparatus to which the present invention is applied will be described with reference to FIG. As this copying machine, a digital exposure type & dry type two-component developing type is used. That is, the drum-shaped photoconductor 1 is uniformly charged by the charging charger 4 whose charge amount is controlled by the charging control unit 3 under the control of the charging operation value determining unit 2 and then exposed by the exposure control unit 5. Electrostatic latent image is formed. Here, in the exposure control unit 5, for example, a document 8 set on the contact glass 6 and covered with a document pressure plate 7 is exposed and illuminated by an exposure lamp, and reflected light from the document 8 is passed through an optical system 10 such as a mirror. Of the digital exposure system in which the image is read by an image pickup device, for example, the CCD 11, and then the optical writing is performed with an exposure amount according to the document image information that has passed through the A / D converter 12, the document image processing unit 13, and the exposure operation value determination unit 14. It is a thing. An exposure laser, an exposure LED array, an exposure lamp, or the like is used as the optical writing light source. The electrostatic latent image thus formed on the photoconductor 1 is developed by the toner of the negative / positive developing type developing device 15 into a visible image, and by the action of the transfer charger 16,
It is transferred onto the transfer paper 17 that is fed at a predetermined timing. The transferred transfer paper 17 is separated from the photoconductor 1 by the action of the separation charger 18, and then moves toward the paper discharge side through the fixing roller 19 and the like.

Here, the charging control system is the charging charger 4.
The charging system is controlled by the charging control unit 3, but a roller charging system or the like may be used. Further, the exposure control system is not limited to such a digital exposure system, but may be an analog exposure system in which the latent image is formed by directly performing the writing exposure on the photoconductor 1 by the reflected light from the original 8. . In any case, the lamp voltage and the light amount can be controlled by controlling the laser power and the exposure time.

As described above, the developing system is a dry two-component developing system. In the developing device 15, the developing sleeve 20 closely opposed to the photoconductor 1 and the toner 23 in the toner hopper 22 in the developing device 21 are provided. A toner supply roller 24 for supplying the toner, an agitator 25 for agitating the toner 23 and the carrier (developer) in the developing device 21, and the like are provided.

Although not particularly shown, the developing sleeve 2
For 0, a developing bias control unit for controlling the developing bias voltage is provided.

Further, for example, the following is provided as sensor means for acquiring information that affects the electrophotographic process. First, a surface potential meter 31 for measuring the surface potential of the photosensitive member 1 such as the charged portion potential, the exposed portion potential, and the residual potential is provided. Also, the developing sleeve 2
Development bias voltmeter 3 for measuring development bias potential of 0
2 are provided. Further, a toner adhesion amount sensor 33 that measures the toner adhesion amount on the surface of the photoconductor 1 is provided. Further, a toner concentration sensor 34 that measures the toner concentration in the developing device 21 is provided. Further, a temperature sensor 35 and a humidity sensor 36 for measuring the environmental temperature and the environmental humidity around the photoconductor 1 are provided.

FIG. 3 shows the potential relationship of the negative / positive developing system in the electrophotographic process of the copying machine as shown in FIG. First, the photoconductor 1 is charged to the charging potential V _D by the charging charger 4, and subsequently, a portion to be an image (exposure portion) is exposed by the exposure control portion 5 with an exposure amount that differs depending on the image density of the exposure portion potential _VL. Becomes Here, the difference between these developing bias voltage V _B and the exposed portion potential V _L of (V _B -V _L) is referred to as "development potential" toner amount proportional to the potential difference becomes the development potential photoreceptor 1 is attached to the surface and developed. In this way, the toner attached to the surface of the photoconductor 1 is transferred to the transfer paper 17 to form an image on the transfer paper 17. Therefore, it is understood that the toner adhesion amount changes depending on the magnitude of the development potential, and for example, it is possible to control the exposure portion potential to an appropriate potential corresponding to the document density,
In the electrophotographic process, especially in the color electrophotographic process, it is important to obtain a high quality image.

Therefore, the relationship between the surface potential of the photosensitive member 1, the toner charge amount, and the toner adhesion amount will be described with reference to FIG. Toner 23 adheres to the surface of the photoconductor 1 in proportion to the development potential. Here, the developing potential is equal to the difference between the surface potential of the photoconductor 1 and the developing bias voltage of the developing sleeve 20 as described above, but the toner adhesion amount is inversely proportional to the toner charge amount. Therefore, FIG.
4A and 4B, assuming that the developing potentials are the same, the toner adhesion state as shown in FIG. 4A is obtained when the toner charge amount is high, and the toner charge amount is low as shown in FIG. The toner is attached as shown in. Simply, if the amount of charge per toner shown in FIG. 4A is twice that of FIG. 4B, it means that the toner adhesion amount is about half.

FIG. 5 is a characteristic diagram showing such a relationship.
become that way. That is, the amount of toner 23 attached to the surface of the photoconductor 1 changes depending on the amount of toner charge, but this amount of toner charge is generated by frictional charging between the developer in the developing device 21 and the toner. Is thought to have a deep relationship with. That is, when the developer is used for a long period of time, the charge capacity changes and it tends to be difficult to be charged.
Therefore, it is considered that monitoring the degree of fatigue of the developer is important in estimating the charge amount of the toner, which is a friction partner, and thus the toner adhesion amount.

Next, FIG. 6 showing the characteristics of the relationship between the toner density and the toner adhesion amount in the developing device 21.
Will be described with reference to. This is a characteristic phenomenon found in the two-component developing method using the developer and the toner 23.
When the toner concentration in 1 is low (that is, when the toner amount relative to the developer is small), the charge amount per toner is high, and vice versa when the toner concentration in the developing device 21 is high. FIG. 6 shows that such a difference in toner charge amount affects the toner adhesion amount.

Further, the relationship between environmental conditions, for example, the fluctuation of humidity and the toner adhesion amount will be described with reference to FIG. 7 showing its characteristics. The toner 23 is mainly charged by being charged by frictional charging with the developer in the developing device 21. Therefore, when the toner is dry, the toner charge amount is high, but when the humidity is high, the toner charge amount is low. FIG. 7 shows that the toner charge amount is affected by the toner charge amount, which is associated with the humidity.

From the results of consideration of these several examples, it is understood that the toner adhesion amount is greatly related to the developing potential as well as the toner charge amount. In addition, the toner 23
Since the toner is charged by frictional charging with the developer, it is understood that if the ease of charging the developer is known, the toner charge amount can be estimated, and thus the toner adhesion amount can be estimated. Conversely, according to FIGS. 5 to 7, if the toner adhesion amount is known, the toner charge amount can be estimated from parameters such as toner density and humidity that affect the development potential and the toner charge amount. .

In this embodiment, the ease of charging the developer is determined by a parameter called "developer fatigue". First, in the embodiment corresponding to the first aspect of the invention, the ease of charging the toner 23 (developer) in the developing device 21 is shown from the relationship between the developing potential and the toner adhesion amount (see FIG. 5). It is configured to estimate the developer fatigue level which is a parameter. Further, in the embodiment corresponding to the invention described in claim 2, in addition to the relationship between the development potential and the toner adhesion amount, the development is performed in consideration of the toner density which influences the toner charging as shown in FIG. It is configured to estimate the degree of agent fatigue. Furthermore, in the embodiment corresponding to the invention described in claim 3, in addition to the relationship between the developing potential, the toner adhesion amount, and the toner concentration, the relationship shown in FIG.
As described above, the developer fatigue level is estimated in consideration of the humidity that affects the toner charging.

Further, in each of the embodiments corresponding to the inventions of claims 4 to 10, the ease of charging of the toner obtained by estimation in the embodiments corresponding to the inventions of claims 1 to 3 is estimated. By using the developer fatigue level shown, the toner adhesion amount is estimated from the relationship between the toner charge amount, the development potential, the toner concentration, and the humidity as shown in FIGS. By the way, in the case of the conventional method, since the development potential and the environmental condition are only monitored, the toner adhesion amount cannot be accurately obtained when the toner charge amount is different.

Next, the parameter operating unit 40 (corresponding to the charging operation value determining unit 2 and the exposure operation value determining unit 14) used in each of the embodiments corresponding to the inventions described in claims 4 to 10.
Is shown in FIG. The parameter operating unit 40 uses the simulation model 4 so that the estimated toner adhesion amount output from the toner adhesion amount simulation model 41 becomes a desired value.
1 is operated, and the development potential at that time is changed to the charging control unit 3 and the exposure control unit 5.
It is configured to be sent to the electrophotographic process control unit such as the above, and set as an image forming condition for the next image forming.

The above toner adhesion amount simulation model 4
1 is, for example, a model 4 in which a transfer function F (ω) is calculated as shown in FIG.
2, there is a neural network 43 using a non-linear theory as shown in FIG. 9B, and a fuzzy model 44 using a non-linear theory as shown in FIG. 9C. Among them, in the present embodiment, the neural network 43 having the generalization ability of interpolating between discrete values even when learning discrete values is used as the toner adhesion amount simulation model 41.

FIGS. 1, 10 and 11 are included in the toner adhesion amount simulation model 41, and serve as a developer deterioration degree estimating means for estimating the developer deterioration degree on the basis of each sensor output and parameter. Neural network for agent fatigue estimation (hereinafter abbreviated as NN for developer fatigue estimation) 45
The example of composition of a, 46a, 47a is shown. The difference between these developer fatigue level estimation NNs 45a, 46a, 47a is input information, and the number of input layer neurons and the number of intermediate layer neurons of a three-layer hierarchical type are appropriately changed according to the number of them. Here, the developer fatigue degree estimation NN45a, 4
As 6a and 47a, those learned by a method such as an error backpropagation method (backpropagation method) so as to reduce an error from a teacher value described later are used.

12 to 14 are included in the toner adhesion amount simulation model 41, and the toner adhesion amount for estimating the toner adhesion amount based on each sensor output, parameter and estimated developer fatigue level is shown. 4 shows an example of the configuration of a toner adhesion amount estimation neural network (hereinafter abbreviated as toner adhesion amount estimation NN) 45b, 46b, 47b that serves as an estimation unit. NN for estimating these toner adhesion amounts
The difference between 45b, 46b, and 47b is input information, and the number of three-layer hierarchical input layer neurons and the number of intermediate layer neurons are appropriately changed according to the number of input information. Here, as the toner adhesion amount estimation NNs 45b, 46b, 47b, those learned by a method such as an error backpropagation method so that an error with a later-described teaching value becomes small are used.

Next, these neural networks 4
The learning of 5-47 will be described. First, learning of the developer fatigue degree estimation NNs 45a, 46a, 47a will be described. These developer fatigue degree estimation NN45a, 46
In the experiment for acquiring the learning data of a and 47a, the learning data is acquired by using various deteriorated developers. For example, in the case of a developer having a rating of 20K sheets, a new developer, 5K, 1
A developer after copying and recording on 0K, 15K, and 20K sheets is prepared. The amount of toner adhering to the surface of the photoconductor 1 after the development with each of the prepared developers with various development potentials is measured.

In the experiment for acquiring the learning data of the developer fatigue degree estimating NN 46a shown in FIG.
The toner density within 1 must also be set to various values. Similarly, in the experiment for acquiring the learning data of the developer fatigue degree estimating NN47a shown in FIG. 11, it is necessary to set various environmental conditions such as temperature and humidity.

The developer fatigue level is specified, for example, such that 0, 5K sheets of the developer after copying and recording are 25, 10K sheets of 50, 15K sheets of 75, and 20K sheets of 100. .

NN45a for estimating the developer fatigue degree shown in FIG.
For the learning data of 1, the development potential and the toner adhesion amount obtained in the above experiment are input, and the developer fatigue degree is used as a teacher value. The learning data of the developer fatigue level estimation NN 46a shown in FIG. 10 uses the development potential, the toner adhesion amount, and the toner concentration obtained in the above experiment as inputs, and the developer fatigue level as a teacher value. The learning data of the developer fatigue level estimation NN 47a shown in FIG. 11 is input with the development potential, the toner adhesion amount, the toner concentration, and the environmental conditions obtained in the above-described experiment, and the developer fatigue level is used as a teacher value.

Next, the toner adhesion amount estimation NN 45b, 4
The learning of 6b and 47b will be described. In the experiment in which the learning data of these toner adhesion amount estimation NN45b, 46b, 47b is taken, the above-mentioned developer fatigue degree estimation NN45 is used.
Similar to the case of acquiring the learning data of a, 46a, and 47a, the learning data is acquired by using various deteriorated developers. The amount of toner adhering to the surface of the photoconductor 1 after the development with each of the prepared developers with various development potentials is measured.

In the experiment for acquiring the learning data of the toner adhesion amount estimating NN 46b shown in FIG.
The toner density within 1 must also be set to various values. Similarly, in the experiment for acquiring the learning data of the toner adhesion amount estimation NN 47b shown in FIG. 14, it is necessary to set various environmental conditions such as temperature and humidity.

Similarly to the case where the learning data of the developer fatigue degree estimating NNs 45a, 46a, 47a is acquired, the developer fatigue degree is, for example, 0. Agent is 25, 10K 50, 15K
The number of sheets is designated as 75, the number of sheets as 20K is designated as 100, and so on.

NN45 for estimating toner adhesion amount shown in FIG.
For the learning data of b, the development potential and the developer fatigue degree obtained in the above experiment are input, and the toner adhesion amount is used as a teacher value. Toner adhesion amount estimation NN 46b shown in FIG.
For the learning data of, the development potential, the toner concentration, and the developer fatigue degree obtained in the above experiment are input, and the toner adhesion amount is used as a teacher value. The learning data of the toner adhesion amount estimation NN 47b shown in FIG. 14 uses the development potential, the toner concentration, the environmental conditions, and the developer fatigue degree obtained in the above-described experiments as inputs, and uses the toner adhesion amount as a teacher value.

<Embodiments corresponding to the invention described in each claim>
Such learned NN45a for estimating the developer fatigue degree,
46a, 47a and NN45b, 46 for estimating toner adhesion amount
Embodiments for each invention described in each claim constituted by using b and 47b will be sequentially described.

First, an embodiment corresponding to the invention described in claim 1 will be described. The electrophotographic process control apparatus according to the present embodiment includes sensor means including a surface potential meter 31, a developing bias voltmeter 32, and a toner adhesion amount sensor 33 shown in FIG.
The output of these sensor means 31 to 33 is used as an input, and the relationship between toner adhesion amount / development potential-developer fatigue level is learned by using the developer fatigue level obtained in advance by experiments as a teacher value. The developer fatigue degree estimating NN 45a as shown in FIG.

At the time of control, one or more of the outputs of the sensor means 31 to 33 at the time of the previous copy recording or the image formation of a specific pattern are input to the developer fatigue degree estimating NN 45a. An estimated developer fatigue level is obtained from the developer fatigue level estimation NN 45a.

According to this embodiment, a parameter indicating the easiness of charging of the developer is obtained from the relationship between the actual development potential and the toner adhesion amount at the time of the previous copy recording or when a specific pattern was formed. Since a certain developer fatigue level is estimated, it can be estimated more accurately than the existing method of estimating the developer fatigue level from the copy counter or the developer agitation time in the developing device. Furthermore, for estimating the developer fatigue level, a NN45 for developer fatigue level estimation having a neural network configuration is used.
Since a is used, even if the combination of toner adhesion amount / development potential-developer fatigue degree is not obtained in the experiment, the relation of toner adhesion amount / development potential-developer fatigue degree is obtained.
The generalization ability of the neural network has the merit of being able to estimate the degree of developer fatigue.

Next, an embodiment corresponding to the invention described in claim 2 will be described. The electrophotographic process control apparatus of this embodiment includes sensor means including the surface electrometer 31, the developing bias voltmeter 32, the toner adhesion amount sensor 33, and the toner concentration sensor 34 shown in FIG. 2, and these sensor means 31 to 34.
10 is used as an input, and the relationship between the toner adhesion amount, the development potential, the toner concentration, and the developer fatigue degree is learned by using the developer fatigue degree obtained by an experiment or the like as a teacher value in advance. And the developer fatigue degree estimating NN 46a.

At the time of control, one or more of the outputs of the sensor means 31 to 34 at the time of the previous copy recording or the image formation of the specific pattern are input to the developer fatigue degree estimating NN 46a. An estimated value of the developer fatigue level is obtained from the developer fatigue level estimation NN 46a.

According to this embodiment, in addition to the effect of the embodiment corresponding to the invention described in claim 1, the toner density information from the toner density sensor 34 is used for the developer fatigue degree estimation N.
By including it in the input of N46a, the parameter affecting the toner charge amount is increased, so that the developer fatigue level can be estimated more accurately.

An embodiment corresponding to the invention of claim 3 will be described. The electrophotographic process control apparatus according to the present embodiment includes a surface potential meter 31, a developing bias voltmeter 32, a toner adhesion amount sensor 33, and a toner concentration sensor 3 shown in FIG.
4, the sensor means consisting of the temperature sensor 35 and the humidity sensor 36, and the outputs of these sensor means 31 to 36 as inputs,
The relationship between the toner adhesion amount, the development potential, the toner concentration, the environmental condition, and the developer fatigue level is learned by using the developer fatigue level obtained by an experiment or the like in advance as a teacher value.
The developer fatigue degree estimating NN 47a as shown in FIG.

At the time of control, one or more of the outputs of the sensor means 31 to 36 at the time of the previous copy recording or the image formation of a specific pattern are input to the developer fatigue degree estimating NN 47a. The developer fatigue degree estimated value is obtained from the developer fatigue degree estimation NN47a.

According to this embodiment, in addition to the effect of the embodiment corresponding to the invention described in claim 2, the temperature sensor 3
5. By including the temperature and humidity information from the humidity sensor 36 in the input of the developer fatigue degree estimation NN 47a, the parameters that affect the toner charge amount are increased, so that the developer fatigue degree can be estimated more accurately. .

Further, an embodiment corresponding to the invention of claim 4 will be described. The electrophotographic process control apparatus according to the present embodiment includes sensor means including a surface potential meter 31, a developing bias voltmeter 32, and a toner adhesion amount sensor 33 shown in FIG.
NN45a for developer fatigue degree estimation as shown in FIG.
The toner adhesion amount estimation NN 45b as shown in FIG. 12 is provided and configured as shown in FIG. As described above, the developer fatigue degree estimating NN 45a has the sensor means 31.
It is a neural network in which the relationship between toner adhesion amount / development potential-developer fatigue degree is learned by using the output of ~ 33 as an input and the developer fatigue degree obtained in advance by experiments or the like as a teacher value. Toner adhesion amount estimation NN45
b receives the estimated value of the developer fatigue degree from the developer fatigue degree estimation NN 45a and the outputs of the sensor means 31 and 32, and
This is a neural network in which the relationship between the developing potential, the developer fatigue level, and the toner adhesion amount is learned by using the toner adhesion amount obtained by experiments or the like in advance as a teacher value.

At the time of control, one or more of the outputs of the sensor means 31 to 33 at the time of the previous copy recording or the image formation of a specific pattern are input to the toner adhesion amount estimating NN 45b. The toner adhesion amount estimation value is obtained from the toner adhesion amount estimation NN 45b. The development potential is adjusted so that this estimated value becomes a desired value, and this development potential is sent to each process control unit and set as the target value for the next copying.

According to this embodiment, since the developer fatigue level, which indicates the ease of toner charging, is used as one of the parameters for estimating the toner adhesion amount, the toner adhesion amount can be estimated more accurately. Therefore, it is possible to properly set and control the next image forming condition based on the highly accurate estimated value.

Further, an embodiment corresponding to the invention described in claim 5 will be described. The electrophotographic process control apparatus according to the present embodiment includes sensor means including the surface potential meter 31, the developing bias voltmeter 32, the toner adhesion amount sensor 33, and the toner concentration sensor 34 shown in FIG. The developer fatigue degree estimation NN 46a and the toner adhesion amount estimation NN 45b as shown in FIG. 12 are provided and configured as shown in FIG. As described above, the developer fatigue degree estimating NN 46a receives the outputs of the sensor units 31 to 34 as input, and uses the developer fatigue degree obtained in advance by experiments as a teacher value.
This is a neural network that has learned the relationship between toner adhesion amount, development potential, toner concentration and developer fatigue level. The toner adhesion amount estimation NN 45b receives the developer fatigue degree estimation value from the developer fatigue degree estimation NN 46a and the outputs of the sensor means 31 and 32 as input, and uses the toner adhesion amount obtained by an experiment or the like in advance as a teacher value. , A developing potential / developer fatigue-toner adhesion amount is a neural network that has been learned.

At the time of control, one or more of the outputs of the sensor means 31 and 32 at the time of the previous copy recording or the image formation of the specific pattern are input to the toner adhesion amount estimating NN 45b. The toner adhesion amount estimation value is obtained from the toner adhesion amount estimation NN 45b. The development potential is adjusted so that this estimated value becomes a desired value, and this development potential is sent to each process control unit and set as the target value for the next copying.

According to this embodiment, since the developer fatigue level, which indicates the ease of toner charging, is used as one of the parameters for estimating the toner adhesion amount, the toner adhesion amount can be estimated more accurately. In particular, in the developer fatigue degree estimation NN46a, the developer fatigue degree is estimated in consideration of the toner concentration.
Since the developer fatigue level can be estimated with higher accuracy, the toner adhesion amount can be estimated with higher accuracy. Therefore, it is possible to properly set and control the next image forming condition based on the highly accurate estimated value.

An embodiment corresponding to the invention of claim 6 will be described. The electrophotographic process control apparatus of this embodiment is shown in FIG.
Surface potential meter 31, developing bias voltmeter 32,
17 is provided with the sensor means including the toner adhesion amount sensor 33 and the toner concentration sensor 34, the developer fatigue degree estimation NN 46a as shown in FIG. 10, and the toner adhesion amount estimation NN 46b as shown in FIG. It is configured as shown. The developer fatigue degree estimating NN 46a is as described in the above embodiment. The toner adhesion amount estimation NN46b is
The estimated value of the developer fatigue degree from the developer fatigue degree estimation NN 46a and the outputs of the sensor means 31, 32, 34 are input,
This is a neural network in which the relationship between the development potential, the developer fatigue level, the toner concentration, and the toner adhesion amount is learned by using the toner adhesion amount obtained in advance by experiments as a teacher value.

At the time of control, one or more of the outputs of the sensor means 31, 32, and 34 at the time of the previous copy recording or the image formation of a specific pattern are used as the toner adhesion amount estimation NN46b.
By inputting this, the toner adhesion amount estimation NN46
An estimated value of the amount of adhered toner is obtained from b. The development potential is adjusted so that this estimated value becomes a desired value, and this development potential is sent to each process control unit and set as the target value for the next copying.

In the case of this embodiment, the same effect as in the case of the embodiment corresponding to the invention described in claim 5 can be obtained, but especially in the toner adhesion amount estimating NN 46b, the toner density is also taken into consideration. Since the adhesion amount is estimated,
It is possible to estimate the toner adhesion amount with higher accuracy.

An embodiment corresponding to the invention of claim 7 will be described. The electrophotographic process control apparatus of this embodiment is shown in FIG.
Surface potential meter 31, developing bias voltmeter 32,
A sensor unit including a toner adhesion amount sensor 33, a toner concentration sensor 34, a temperature sensor 35, and a humidity sensor 36, and FIG.
The developer fatigue degree estimating NN 46a as shown in FIG. 0 and the toner adhesion amount estimating NN 47b as shown in FIG. 14 are configured as shown in FIG. The developer fatigue degree estimating NN 46a is as described in the above embodiment.
The toner adhesion amount estimation NN 47b uses the developer fatigue degree estimation value from the developer fatigue degree estimation NN 46a and the sensor unit 3.
The output of 1, 32, 34 to 36 is input, and the relationship between development potential, toner concentration, environmental conditions, developer fatigue level and toner adhesion amount is learned by using the toner adhesion amount obtained in advance through experiments as a teacher value. This is the neural network that I had set.

At the time of control, each sensor means 31, 32, 34 to 3 at the time of the previous copy recording or the image formation of a specific pattern.
One or more of the six outputs are used for the toner adhesion amount estimation NN
By inputting 47b, the toner adhesion amount estimation N
An estimated toner adhesion amount value is obtained from N47b. The developing potential is adjusted so that this estimated value becomes a desired value, and this developing potential is sent to each process control unit,
Use the target value for the next copy.

Also in the case of the present embodiment, the above claims 5, 6
Although the same effect as in the case of the embodiment corresponding to the described invention can be obtained, in particular, in the toner adhesion amount estimation NN 47b, the toner adhesion amount is estimated in consideration of the environmental conditions such as temperature and humidity, so Therefore, it becomes possible to estimate the toner adhesion amount with high accuracy.

An embodiment corresponding to the invention of claim 8 will be described. The electrophotographic process control apparatus of this embodiment is shown in FIG.
Surface potential meter 31, developing bias voltmeter 32,
A sensor unit including a toner adhesion amount sensor 33, a toner concentration sensor 34, a temperature sensor 35, and a humidity sensor 36, and FIG.
The developer fatigue degree estimating NN 47a as shown in FIG. 1 and the toner adhesion amount estimating NN 45b as shown in FIG. 12 are configured as shown in FIG. As described above, the developer fatigue degree estimating NN 47a has the sensor means 31.
Neural that learned the relationship between toner adhesion amount, development potential, toner concentration, environmental conditions-developer fatigue degree, using the output of ~ 36 as input, and the developer fatigue degree obtained through experiments etc. as a teacher value. It is a network. The toner adhesion amount estimating NN 45b is a developer fatigue degree estimating NN.
Estimated developer fatigue level from 47a and sensor means 31, 3
This is a neural network in which the relationship between the developing potential, the developer fatigue degree and the toner adhesion amount is learned by using the output of 2 as an input and the toner adhesion amount obtained by an experiment or the like in advance as a teacher value.

At the time of control, one or more of the outputs of the sensor means 31, 32 at the time of the previous copy recording or the image formation of the specific pattern are input to the toner adhesion amount estimating NN 45b. The toner adhesion amount estimation value is obtained from the toner adhesion amount estimation NN 45b. The development potential is adjusted so that this estimated value becomes a desired value, and this development potential is sent to each process control unit and set as the target value for the next copying.

According to this embodiment, since the developer fatigue level, which indicates the ease of toner charging, is used as one of the parameters for estimating the toner adhesion amount, the toner adhesion amount can be estimated more accurately. In particular, in the developer fatigue estimation NN47a, the developer fatigue is estimated in consideration of the toner concentration and the environmental conditions, and the developer fatigue is estimated with higher accuracy. It will be highly accurate. Therefore, it is possible to properly set and control the next image forming condition based on the highly accurate estimated value.

An embodiment corresponding to the invention of claim 9 will be described. The electrophotographic process control apparatus of this embodiment is shown in FIG.
Surface potential meter 31, developing bias voltmeter 32,
A sensor unit including a toner adhesion amount sensor 33, a toner concentration sensor 34, a temperature sensor 35, and a humidity sensor 36, and FIG.
The developer fatigue degree estimating NN 47a as shown in FIG. 1 and the toner adhesion amount estimating NN 46b as shown in FIG. 13 are provided and configured as shown in FIG. The developer fatigue level estimation NN47a is as described in the above embodiment. The toner adhesion amount estimation NN 46b receives the estimated value of the developer fatigue degree from the developer fatigue degree estimation NN 47a and the outputs of the sensor means 31, 32, 34 as an input, and teaches the toner adhesion amount obtained in advance by experiments or the like. The value is a neural network in which the relationship between the developing potential, the toner concentration, the developer fatigue level, and the toner adhesion amount is learned.

At the time of control, one or more of the outputs of the sensor means 31, 32, and 34 at the time of the previous copy recording or the image formation of a specific pattern are used to estimate the toner adhesion amount NN46b.
By inputting this, the toner adhesion amount estimation NN46
An estimated value of the amount of adhered toner is obtained from b. The development potential is adjusted so that this estimated value becomes a desired value, and this development potential is sent to each process control unit and set as the target value for the next copying.

In the case of this embodiment, the same effect as in the case of the embodiment corresponding to the invention described in claim 8 can be obtained, but especially in the toner adhesion amount estimating NN 46b, the toner density is also taken into consideration. Since the adhesion amount is estimated,
It is possible to estimate the toner adhesion amount with higher accuracy.

An embodiment corresponding to the invention of claim 10 will be described. The electrophotographic process control apparatus according to the present embodiment includes a surface potential meter 31 and a developing bias voltmeter 3 shown in FIG.
2, toner adhesion amount sensor 33, toner concentration sensor 34,
Sensor means comprising a temperature sensor 35 and a humidity sensor 36,
NN47a for estimating the developer fatigue degree as shown in FIG.
And the NN 47 for estimating the toner adhesion amount as shown in FIG.
21 and is configured as shown in FIG. The developer fatigue level estimation NN47a is as described in the above embodiment. The toner adhesion amount estimation NN 47b receives the developer fatigue degree estimation value from the developer fatigue degree estimation NN 47a and the outputs of the sensor means 31, 32, 34 to 36 as input, and the toner adhesion amount obtained in advance by experiments or the like. Is a neural network in which the relationship between development potential, toner concentration, environmental conditions, developer fatigue level and toner adhesion amount is learned.

At the time of control, each sensor means 31, 32, 34 to 3 at the time of the previous copy recording or the image formation of a specific pattern.
One or more of the six outputs are used for the toner adhesion amount estimation NN
By inputting 47b, the toner adhesion amount estimation N
An estimated toner adhesion amount value is obtained from N47b. The developing potential is adjusted so that this estimated value becomes a desired value, and this developing potential is sent to each process control unit,
Use the target value for the next copy.

Also in the case of this embodiment, the above claims 8 and 9 can be applied.
Although the same effect as in the case of the embodiment corresponding to the described invention can be obtained, in particular, in the toner adhesion amount estimation NN 47b, the toner adhesion amount is estimated in consideration of the environmental conditions such as temperature and humidity, so Therefore, it becomes possible to estimate the toner adhesion amount with high accuracy.

[0076]

According to the electrophotographic process control apparatus of the present invention, an image forming apparatus having an electrophotographic process mechanism including a developing device for developing an electrostatic latent image formed on a photoconductor is provided. In the electrophotographic process control apparatus, sensor means for respectively measuring the surface potential of the photoconductor, the developing bias potential in the developing device, and the toner adhesion amount on the surface of the photoconductor, and at least one of the outputs from the sensor means. By inputting one of them as input, a developer fatigue degree estimating means for estimating the fatigue degree of the developer by simulating the relationship between the development potential, the toner adhesion amount, and the developer fatigue degree is provided. Since it is configured to estimate using a simulated model from the relationship with the toner adhesion amount, it has a large effect on the toner charge amount, and by extension, on the toner adhesion amount. The developer fatigue can be estimated accurately, can be utilized for high-precision estimation of the amount of toner adhesion, which is one of parameters for determining the image forming condition that.

In addition, according to the electrophotographic process control apparatus of the present invention as defined in claims 2 and 3, environmental conditions such as toner concentration and temperature / humidity are taken into consideration in estimating the degree of fatigue of the developer. It is possible to estimate the developer fatigue level with high accuracy.

According to the electrophotographic process control apparatus of the fourth to tenth aspects, in addition to the developing potential,
As described above, considering the developer fatigue degree estimated by the developer fatigue degree estimating means in the electrophotographic process control apparatus of the invention according to claims 1 to 3, further, the environment such as toner concentration, temperature, humidity, etc. The toner adhesion amount is estimated using a simulation model in consideration of the conditions, so the toner adhesion amount can be estimated with high accuracy, and this can be used to determine the image formation conditions for the next image formation. It is possible to achieve high quality by setting it as one of the parameters to be set.

According to the electrophotographic process control apparatus of the first to tenth aspects, a neural network can be used as the simulation model constituting the developer fatigue degree estimating means and the toner adhesion amount estimating means. Therefore, the generalization ability of the neural network has an effect that the fatigue degree of the developer and the toner adhesion amount can be estimated with less experiments.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a neural network forming a developer fatigue degree estimating means corresponding to the invention of claim 1 in one embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing the entire copying machine.

FIG. 3 is an explanatory diagram showing a potential relationship of a negative / positive developing system.

FIG. 4 is an explanatory view schematically showing the toner adhesion state on the surface of the photoconductor according to the amount of toner charge.

FIG. 5 is a characteristic diagram showing a relationship between a toner charge amount and a toner adhesion amount.

FIG. 6 is a characteristic diagram showing a relationship between toner density and toner adhesion amount.

FIG. 7 is a characteristic diagram showing a relationship between humidity fluctuation and toner adhesion amount.

FIG. 8 is a block diagram showing a basic configuration of a parameter operating unit.

FIG. 9 is a block diagram showing a configuration example of a simulated model.

FIG. 10 is a schematic diagram showing a neural network constituting a developer fatigue degree estimating means corresponding to the invention of claim 2 in one embodiment of the present invention.

FIG. 11 is a schematic diagram showing a neural network constituting a developer fatigue degree estimating means corresponding to the invention of claim 3 in one embodiment of the present invention.

FIG. 12 is a schematic diagram showing a neural network forming the toner adhesion amount estimating means included in the inventions of claims 4, 5 and 8 in one embodiment of the present invention.

FIG. 13 is a schematic diagram showing a neural network forming the toner adhesion amount estimating means included in the inventions of claims 6 and 9 in one embodiment of the present invention.

FIG. 14 is a schematic diagram showing a neural network constituting the toner adhesion amount estimating means included in the inventions of claims 7 and 10 in an embodiment of the present invention.

FIG. 15 is a schematic view showing an embodiment corresponding to the invention of claim 4 among the embodiments of the present invention.

FIG. 16 is a schematic view showing an embodiment corresponding to the invention of claim 5 among the embodiments of the present invention.

FIG. 17 is a schematic view showing an embodiment corresponding to the invention of claim 6 in the embodiment of the present invention.

FIG. 18 is a schematic view showing an embodiment corresponding to the invention of claim 7 in an embodiment of the present invention.

FIG. 19 is a schematic view showing an embodiment corresponding to the invention of claim 8 among the embodiments of the present invention.

FIG. 20 is a schematic view showing an embodiment corresponding to the invention of claim 9 in an embodiment of the present invention.

FIG. 21 is a schematic view showing an embodiment corresponding to the invention of claim 10 in an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 photoconductor 15 developing device 21 developing device 23 toner 31-36 sensor means 45a, 46a, 47a developer fatigue degree estimating means 45b, 46b, 47b toner adhesion amount estimating means

Claims (10)

[Claims] 1. An electrophotographic process controller for an image forming apparatus having an electrophotographic process mechanism including a developing device for developing an electrostatic latent image formed on a photoconductor, comprising: a surface potential of the photoconductor; A sensor means for measuring the developing bias potential in the apparatus and the toner adhesion amount on the surface of the photoconductor, and at least one of the outputs from the sensor means as an input, the development potential, the toner adhesion amount, and the developer fatigue level. An electrophotographic process control device comprising: a developer fatigue degree estimating means for simulating the relationship to estimate the fatigue degree of the developer. 2. An electrophotographic process controller for an image forming apparatus having an electrophotographic process mechanism including a developing device for developing an electrostatic latent image formed on a photoconductor, comprising: a surface potential of the photoconductor; Sensor means for measuring the developing bias potential in the apparatus, the toner adhesion amount on the surface of the photoconductor, and the toner concentration in the developing apparatus, and the developing potential toner using at least one of the outputs from the sensor means as an input. An electrophotographic process control device comprising: a developer fatigue degree estimating means for simulating a relationship between an adhesion amount, a toner concentration, and a developer fatigue degree, and estimating a developer fatigue degree. 3. An electrophotographic process control device for an image forming apparatus having an electrophotographic process mechanism including a developing device for developing an electrostatic latent image formed on a photoconductor, comprising: a surface potential of the photoconductor; Sensor means for measuring the developing bias potential in the apparatus, the amount of toner adhering to the surface of the photoconductor, the toner concentration in the developing apparatus, and environmental conditions such as temperature and humidity, and at least one of the outputs from the sensor means. It is equipped with a developer fatigue degree estimation means for estimating the fatigue degree of the developer by simulating the relationship among the development potential, the toner adhesion amount, the toner concentration, the environmental conditions, and the developer fatigue degree. And an electrophotographic process control device. 4. An electrophotographic process control device for an image forming apparatus having an electrophotographic process mechanism including a developing device for developing an electrostatic latent image formed on a photoconductor, comprising: a surface potential of the photoconductor; A sensor means for measuring the developing bias potential in the apparatus and the toner adhesion amount on the surface of the photoconductor, and at least one of the outputs from the sensor means as an input, the development potential, the toner adhesion amount, and the developer fatigue level. Developer fatigue degree estimating means for simulating the relationship to estimate the fatigue degree of the developer, at least one of an output related to the surface potential and the developing bias potential from the sensor means, and an output from the developer fatigue degree estimating means. Toner adhesion that estimates the toner adhesion amount by simulating the relationship between development potential, developer fatigue level, and toner adhesion amount An electrophotographic process control device comprising: an amount estimating means; 5. An electrophotographic process control apparatus for an image forming apparatus having an electrophotographic process mechanism including a developing device for developing an electrostatic latent image formed on a photoconductor, comprising: a surface potential of the photoconductor; Sensor means for measuring the developing bias potential in the apparatus, the toner adhesion amount on the surface of the photoconductor, and the toner concentration in the developing apparatus, and the developing potential toner using at least one of the outputs from the sensor means as an input. Developer fatigue degree estimating means for simulating the relationship between the amount of adhered toner, toner concentration and developer fatigue degree, and estimating the fatigue degree of the developer, and the output relating to the surface potential and the developing bias potential from the sensor means and the developer. At least one of the output from the fatigue estimation means is used as an input to simulate the relationship between development potential, developer fatigue, and toner adhesion amount. An electrophotographic process control device, comprising: a toner adhesion amount estimating means for estimating a toner adhesion amount by executing a process. 6. An electrophotographic process control apparatus for an image forming apparatus having an electrophotographic process mechanism including a developing device for developing an electrostatic latent image formed on a photoconductor, the surface potential of the photoconductor, the development Sensor means for measuring the developing bias potential in the apparatus, the toner adhesion amount on the surface of the photoconductor, and the toner concentration in the developing apparatus, and the developing potential toner using at least one of the outputs from the sensor means as an input. A developer fatigue degree estimating means for simulating the relationship between the adhesion amount, the toner concentration, and the developer fatigue degree, and estimating the fatigue degree of the developer; and an output relating to the surface potential, the developing bias potential and the toner concentration from the sensor means. At least one of the output from the developer fatigue estimation means is used as an input to develop potential, toner concentration, developer fatigue, toner Adhesion amount of relationship electrophotographic process control apparatus characterized by simulating provided and the toner adhesion amount estimating means for estimating the amount of toner adhesion, the a. 7. An electrophotographic process controller for an image forming apparatus having an electrophotographic process mechanism including a developing device for developing an electrostatic latent image formed on a photoconductor, comprising: a surface potential of the photoconductor; Developing bias potential in the apparatus, toner adhesion amount on the surface of the photoconductor, toner concentration in the developing apparatus, and sensor means for measuring environmental conditions such as temperature and humidity, and surface potential from each of the sensor means, developing Bias potential,
A developer fatigue degree estimating means for estimating the fatigue degree of the developer by simulating the relationship between the development potential, the toner adhesion amount, the toner concentration, and the fatigue degree of the developer by inputting at least one of the outputs relating to the toner adhesion amount and the toner concentration. And at least one of the output from the sensor means relating to the surface potential, the developing bias potential, the toner concentration and the environmental condition and the output from the developer fatigue degree estimating means as input, the development potential, the toner concentration, the environmental condition and the development. An electrophotographic process control device comprising: a toner adhesion amount estimating means for simulating the relationship between the agent fatigue level and the toner adhesion amount to estimate the toner adhesion amount. 8. An electrophotographic process control apparatus for an image forming apparatus having an electrophotographic process mechanism including a developing device for developing an electrostatic latent image formed on a photoconductor, comprising: a surface potential of the photoconductor; Sensor means for measuring the developing bias potential in the apparatus, the amount of toner adhering to the surface of the photoconductor, the toner concentration in the developing apparatus, and environmental conditions such as temperature and humidity, and at least one of the outputs from the sensor means. And a developer fatigue degree estimating means for estimating the fatigue degree of the developer by simulating the relationship among the development potential, the toner adhesion amount, the toner concentration, the environmental condition, and the developer fatigue degree. The development potential / developer fatigue is determined by inputting at least one of the output relating to the potential and the developing bias potential and the output from the developer fatigue degree estimating means. An electrophotographic process control device, comprising: a toner adhesion amount estimating means for simulating a relationship between labor and toner adhesion amount to estimate the toner adhesion amount. 9. An electrophotographic process control apparatus for an image forming apparatus having an electrophotographic process mechanism including a developing device for developing an electrostatic latent image formed on a photoconductor, comprising: a surface potential of the photoconductor; Sensor means for measuring the developing bias potential in the apparatus, the amount of toner adhering to the surface of the photoconductor, the toner concentration in the developing apparatus, and environmental conditions such as temperature and humidity, and at least one of the outputs from the sensor means. And a developer fatigue degree estimating means for estimating the fatigue degree of the developer by simulating the relationship among the development potential, the toner adhesion amount, the toner concentration, the environmental condition, and the developer fatigue degree. At least one of the output relating to the potential, the developing bias potential and the toner concentration and the output from the developer fatigue degree estimating means is used as an input. An electrophotographic process control apparatus comprising: a toner adhesion amount estimating means for simulating the relationship among toner, toner concentration, developer fatigue, and toner adhesion amount, and estimating the toner adhesion amount. 10. An electrophotographic process control device for an image forming apparatus having an electrophotographic process mechanism including a developing device for developing an electrostatic latent image formed on a photoconductor, comprising: a surface potential of the photoconductor; Sensor means for measuring the developing bias potential in the apparatus, the amount of toner adhering to the surface of the photoconductor, the toner concentration in the developing apparatus, and environmental conditions such as temperature and humidity, and at least one of the outputs from the sensor means. And a developer fatigue degree estimating means for estimating the fatigue degree of the developer by simulating the relationship among the development potential, the toner adhesion amount, the toner concentration, the environmental condition, and the developer fatigue degree. At least one of the output relating to the potential, the developing bias potential, the toner concentration and the environmental condition and the output from the developer fatigue degree estimating means is used as an input. An electrophotographic process control device comprising: a toner adhesion amount estimation means for simulating the relationship among image potential, toner concentration, environmental conditions, developer fatigue, and toner adhesion amount, and estimating the toner adhesion amount. .