JPH0327060A - Image forming device - Google Patents

Abstract

PURPOSE:To improve the efficiency of a maintenance work by providing a means for controlling process based on the physical value of electrophotographic process, for storing process setting value and the physical value and for erasing information when a prescribed period passes. CONSTITUTION:The surface potential of a photosensitive drum is measured by a surface electrometer 90 provided between the exposure position of a copying machine and an image eraser. A toner concentration sensor 80 measures a toner weight ratio to the overall weight of a developer from the magnetic permeability of a developer. Based on these measured values, a first CPU 201 controlls the process. The process setting value at the time of the control and the above measured values are stored by a RAM 210 and displayed on a message display part 117 as required. The stored information is erased when the period set by the timing means of a second CPU 221 in advance passes. Thus, the capacity reduction of a storage means is performed and process for obtaining proper image quality is readily applied.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus that forms a hard copy image using an electrophotographic process. [Prior Art] Electrophotographic processes have been widely used as a method for forming hard copy images in image forming devices such as copying machines, facsimile machines, and optical printers using laser beams or LED arrays. The electrophotographic process includes a charging process in which the surface of a photoreceptor is uniformly charged, an exposure process in which the surface of the photoreceptor is exposed to light in accordance with image information to partially remove the 1L charge and form a latent image; It consists of a developing process in which toner in a developer is attached to a latent image to form a toner image, a transfer process in which the toner image is transferred to recording paper, and a fixing process in which the toner image transferred to the recording paper is fixed. When using an image format using an electrophotographic process, in order to obtain a hard copy image of appropriate (i.e. standard) quality, the physical property values (surface potential of the photoreceptor, exposure amount, , toner concentration, etc.), and the operation of each mechanical part is regulated according to the physical property values. However, usually, the specific physical property values gradually deviate from the determined values due to the frequency of use and the environment of the installation location (temperature, humidity, vibration, etc.). In other words, the image quality of hard copy images gradually changes due to the adhesion of impurities to the photoreceptor, deterioration of the exposure lamp, dirt on the optical system's ξ-color, and aging changes in the circuit constants of the control circuit. Please note that sudden changes in image quality may occur. For this reason, for example, service personnel operate the image forming unit during periodic inspections, check the image quality by looking at the hard copy image at that time, and perform cleaning and cleaning as necessary.
We are taking measures such as replacing parts and changing settings for each mechanical part by operating dip switches. [Problems to be Solved by the Invention] With conventional image capture devices, service personnel cannot know the operating conditions (conditions) before the time of inspection. In other words, even if there is a difference between the image quality at the time of inspection and the appropriate image quality, it is not possible to know whether the difference occurred suddenly or gradually. There was a problem in that it was difficult to identify and take appropriate measures.

For this reason, if symptomatic measures were taken to obtain hard copy images of appropriate quality, there was a possibility that the deterioration of various parts would be accelerated. When a service engineer determines whether each part is good or bad based on past changes in operating status, the sampling period for the necessary information differs depending on the length of the target period. In other words, normally, the larger the amount of information, the more precise the investigation can be performed, but especially when investigating long-term trends, if the sampling period is short and the amount of information is large, it may be difficult to understand trends in the trends. This may become difficult and reduce the efficiency of maintenance work. Furthermore, storage capacity is limited due to cost constraints. In view of the above-mentioned problems, the present invention makes it possible to identify the cause of a change in the image quality of a hard copy image and take appropriate measures to obtain appropriate image quality without impairing the efficiency of maintenance work. The purpose is to provide an image-based discipline device. (Means for Solving No. 218B) In order to solve the above-mentioned problem, the invention of claim 1 provides an image forming apparatus that forms a hard copy image using an electrophotographic process, which a sensor means for measuring a value; a process control means for controlling an electrophotographic process based on the output of the sensor means; and at least a process setting value set by the process control means and a value measured by the sensor means. The invention is characterized in that it is provided with a storage means for storing one as management information and a timekeeping means for generating date information and time information, and the management information is erased when a preset storage period has elapsed. The invention of claim 2 is characterized in that, in addition to the above configuration, a display means for displaying the management information is provided. [Operation] The sensor means is an electronic sensor. The physical property values associated with the photographic process are measured. The process control means controls the electrophotographic process based on the output of the sensor means. The storage means stores the process setting values set by the process control means and the measured values by the sensor means. The timekeeping means generates date information and time information.
Management information is deleted when a preset storage period has elapsed. The display means displays management information. [Examples] Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a front sectional view showing the main parts of a copying machine A.

In the figure, the photosensitive drum 5 is arranged so as to be rotatable at a constant circumferential speed V in the direction of the arrow Ma, and around it there are a charging medium 6, an inter-image eraser 1O, a developing device 7, transfer charger 28, separation charger 29, cleaning device 9, and main eraser 8
is installed. Further, a surface electrometer 90 for measuring the surface potential of the photoreceptor drum 5 is provided between the exposure position IX2 and the inter-image eraser 10.
A reflective photosensor 19 consisting of a light emitting element 19a and a light receiving element 19b is provided between the cleaning device 9 and the reference toner image to measure the density of the reference toner image. The surface of the photosensitive drum 5 is uniformly charged by passing the charging charge +6, and the optical system 2 is charged at the exposure position X2.
exposed by 0. The surface charge on the photoreceptor drum 5 is partially removed by exposure, and a latent image corresponding to the document D is formed on the surface of the photoreceptor drum 5. Surface charges in areas other than the latent image are erased by an inter-image eraser 10. The optical system 20 includes an exposure lamp 2l that irradiates an original D placed on an original table glass l, mirrors 22a to d for guiding reflected light B from the original D to an exposure position IFX2, and a projection lens 23. It is configured. During exposure scanning for the document D, the exposure lamp 21 and mirror 22a move in the direction of arrow Mb at a speed of v/m (m is the copying magnification), and the ξ mirrors 22b and 22C are movable at a speed of v/2 m. There is. The latent image formed on the surface of the photosensitive drum 5 is developed by a developing device 7 and visualized as a toner image. The developing device 7 uses a developer made of a mixture of a magnetic carrier and an insulating toner, and uses a well-known magnetic brush method to attach the toner to the latent image (charge existing area, that is, the non-exposed area) passing through the development position X3. Perform so-called normal rotation development. Inside the developing tank 70, a developing sleeve 71 containing a magnetic roller 72, a height regulating plate 73, a bucket roller 74, and a screw roller 75 are provided, and a toner concentration sensor 80 is arranged below the screw roller 75. ．． When the bucket roller 74 rotates in the direction of the arrow Mc, the developer is attracted to the outer peripheral surface of the developing sleeve 71 by the magnetic force of the magnetic roller 72, and is conveyed to the developing position X3 based on the rotation of the developing sleeve 71 in the direction of the arrow Md. It will be done. The toner concentration sensor 80 is used to measure the weight ratio T/C [wt%] of toner to the entire developer from the magnetic permeability of the developer. A toner tank 76 is provided at the top of the developer tank 70, and a toner supply roller 77 is provided at the bottom. When the toner replenishment roller 77 is rotationally driven by the replenishment motor 78, the screw roller 75 is removed from the toner tank 76.
Hetner is replenished. The replenished toner is stirred and mixed with the developer already present inside the developer tank 70 by the rotation of the scratcher roller 75 and sent to the bucket roller 74 . Frictional charging occurs due to stirring and mixing, and the magnetic carrier and toner are charged with opposite polarities. The negative polarity toner is transferred to the photosensitive drum 5 at the development position X3.
It adheres to the surface of the photoreceptor drum 5 due to electrostatic adsorption with the surface charge. At this time, a developing bias VB of a predetermined voltage is applied to the developing sleeve 71 in order to prevent toner from adhering to the surface of the photosensitive drum 5 due to residual charges (charges remaining in the exposed portion). On the other hand, the toner P is conveyed by the timing roller 30 in synchronization with the rotation of the photosensitive drum 5, and transferred to the toner image of the toner P by the transfer charger 28 at the transfer position X4. The paper P on which the toner image has been transferred is separated from the photosensitive drum 5 by a separation charger 29 and sent to a fixing device (not shown).

Thereafter, the surface of the photoreceptor drum 5 is cleaned by a cleaning device 9
The remaining toner is removed by main eraser 8.
The residual charge is removed and the image is prepared for the next exposure. FIG. 2 is an enlarged view of a part of the optical system 20. The slider unit 24 supporting the exposure lamp 21 and the mirror 22a is provided so as to be movable back and forth below the document table glass 1 in order to expose and scan the document D as described above during the copying operation. ! During copy adjustment, it is placed at adjustment position Y1 or Y2. The lower surface of the main body upper cover 26 of the copying machine A has an adjustment position Y.
Adjustment seal 25a 25 to correspond to l, Y2
b is attached. The u4 adjustment seal 25a has a reflectance corresponding to the background (white background) of a normal manuscript paper, and the adjustment seal 25b has a reflectance corresponding to a gray background (halftone image).

FIG. 3 is a diagram showing the structure of the charger 6 and the output circuit 202.

The charging charger 6 includes a charge wire 61 and a stabilizer plate 6.
4. It is a scorotron type charger constructed from a Messier-shaped grid 63. A constant high voltage is supplied to the charge wire 61 from a high voltage transformer 62 that is turned on and off by an I CPU 201, which will be described later. The grid 63 is grounded via series-connected varistors 65a-i in the output circuit 202, and the varistors 65
Short circuit switches SW1 to SW8 are connected between both terminals of a to h, respectively.
It is said that short circuit is possible. The potential of the grid 63 is controlled by turning on and off each of the shorting switches SW1 to SW8 in response to a control signal from the ICPU 201.
As a result, the amount of charge directed from the charge wire 61 to the surface of the photoreceptor drum 5 is controlled, and the surface potential of the photoreceptor drum 5 is set.

Figure 4 is a diagram showing the setting level of 6 during charging. In this embodiment, the rated voltage of the varistors 65a-h is 15
The rated voltage of the varistor 651 is set to 790 volts, and the surface potential of the photosensitive drum 5 can be set in nine levels from levels 1 to 9 at a pitch of 15 volts, with the standard level 5 being the center. For example, at level 5, control is performed to turn on the shorting switches SW1 to SW4 so that the surface potential of the photosensitive drum 5 becomes 650 volts. Note that it is also possible to increase the number of levels by making the rated voltages of the varistors 65a to 65h different from each other. In the following explanation, the set level of the charger 6 will be referred to as "rHV level". FIG. 5 is a block diagram of the control circuit 200 of copying machine A.

The control circuit 200 controls the entire copying machine A.
CPU201, 2nd CPU221SRA with clock function
It has M209, 210, ROM2 1 1, etc. One RAM 209 is backed up by a main power supply (not shown) and is initialized when the main power supply is turned off. Further, the other RAM 210 is backed up by a battery, and the data written in the RAM 2 10 is retained regardless of whether the main power is turned on or off. 212-2
14 is a data path connecting each of the RAMs 209, 210 and ROM 211 to the ICP tJ201. The output voltage VD of the surface electrometer 90, the output voltage VT of the toner concentration sensor 80, and the output voltage VP of the photosensor 19 are stored in the ICPU 201, respectively.
It is converted into a digital signal by the D converters 205 to 207, and is inputted to the exposure lamp power supply 50 for lighting the exposure lamp 2l and the high voltage power supply 40 for applying the developing bias VB. 1, a control signal is applied via D/A converters 203 and 204. 208 is a power source for driving the replenishment motor 78; 216 is an operation panel 100 and an ICPU 20, which will be described later;
This is an interface for sending and receiving data to and from 1. Further, 223 is an online controller for communication with an external management device N227, which will be described later.

FIG. 9 shows the surface potential VH of the photosensitive drum 5 and the surface potential meter 9.
1 is a graph showing the relationship between output voltage VD of 0. As shown in the figure, when the surface potential VH is 70 volts, the output voltage VD is 0.35 volts, and similarly when the surface potential VH is 350 volts, the output voltage VD is 1.75 volts.
Volt, when the surface potential VH is 650 volts, the output voltage V
D is 3.25 volts. 70 at surface potential VH
, 350.650 volts is the bright potential VR in copying machine A,
These are standard values for each of the gray potential vl and dark potential vO. The bright potential VR is a potential corresponding to a portion where static electricity has been removed by exposure (a portion corresponding to the white background portion of the document D), and even under the best conditions, it does not reach 0 volts due to residual charges.
If the bright potential VR is 110 volts or less, it is appropriate, if it exceeds 110 volts and up to 150 volts, it is inappropriate but not abnormal, and if it exceeds 150 volts, it is abnormal. In addition, in this embodiment, the adjustment seal 25a
The potential of the exposed part corresponding to is defined as the bright potential VR. The gray potential vl is the potential of the exposed portion corresponding to the adjustment seal 25b, and the dark potential vO is the potential of the exposed portion corresponding to the adjustment seal 25b.
This is the potential of the part of the surface opposite to the unexposed part (black part). The gray potential vi1, the dark potential vO, and the developing bias VB are determined based on the bright potential VR. That is, the optimum values corresponding to the standard electrophotographic process conditions defined by the shape, material, etc. of the photosensitive drum 5, the developing device 17, etc. described above are shown by equations (1) to (3).

VB-VR+150 ・ (1) vi-vB+1
30 ・ (2) VO-VB+430 ・
(3) FIG. 10 is a diagram showing the setting level of the developing bias VB. As shown in equation (1), the optimal difference between the developing bias VB and the bright potential VR is 150 volts. When the voltage is lower than 150 volts, toner adhesion to exposed areas (portions with residual charge), so-called background staining occurs, and when the voltage is higher than 150 volts, adhesion of magnetic carriers occurs. Therefore, in this embodiment, the standard developing bias VB (220-70+
It is possible to set the developing bias VB in nine stages at a pitch of 10 volts, with level 5 as the target value (150 volts). In the following explanation, the set level of the developing bias VB will be referred to as the "VB level".

Figure 6 shows the toner weight ratio T/C and the toner concentration sensor 80.
This is a graph showing the relationship between the output voltage VT. The value of the toner weight ratio T/C defined as standard electrophotographic process conditions (standard value) is 5 [Wt%],
At this time, the output voltage VT of the toner concentration sensor 80 is 2
．． It is 85 volts. This standard value is toner weight ratio T/C
When performing a copying operation using the setting value of
01 is the reference potential of 2.85 volts and the output voltage VT
Compare with the value of . The value of output voltage VT is r2.85"
, that is, when the toner weight ratio T/C is less than the standard value, the ICPU 201 controls the replenishment motor 7.
Turn on the power supply 208 of B, replenish toner, and bring the toner weight ratio T/C close to the standard value. In this way, control to maintain the toner weight ratio T/C at the set value is performed at any time during the copying operation, but the set value of the toner weight ratio T/'C is determined based on self-diagnosis in the image adjustment process described later. Be changed.

Figure 7 shows the set level of toner weight ratio T/C and dark potential vO.
FIG. In this embodiment, the setting value of the toner weight ratio T/C can be set in four levels of levels 1 to 4. In the following explanation, the setting level of the toner weight ratio T/C will be referred to as "rT/C level". Generally, as the value of the toner weight ratio T/C increases, the development copying efficiency increases, so even when the potential difference between the photoreceptor drum 5 and the developing sleeve 71 is reduced, the toner weight ratio T/C increases. By increasing the size, it is possible to obtain a hard copy image with appropriate density. Therefore, in the image adjustment process described later, the standard toner weight ratio T
/C, that is, when the output adjustment of the charger 6 reaches its limit at the T/C level "1", the T/C level is changed. However, the toner weight ratio T/C is 8 [w
If the toner weight ratio T/C exceeds 8 [wt%], excessive driving torque is applied to the bucket roller, etc., and problems such as toner overflowing from the developer tank 70 occur. Therefore, the upper limit of the toner weight ratio T/C is 8 [wt%]. It is stipulated. FIG. 11 is a diagram showing the setting level of exposure amount. The exposure amount is set by controlling the lighting power supplied from the exposure lamp power supply 50 to the exposure lamp 21. *Photograph A
Here, nine levels of settings are possible in the range of 1.6 to 2.4 [Lux-sec], with level 5 having a target value of 2.00 [Lux-sec]. Note that hereinafter, the exposure setting level will be referred to as "rEXP level". Figure 8 shows the output voltage vP of the photosensor l9 and the estimated concentration ID.
This is a graph showing the relationship between This graph corresponds to the relationship between the density of the toner image on the photoreceptor drum 5 and the density actually measured for a hard copy image obtained by transferring and fixing the toner image onto paper P. For example, if the value of the output voltage VP is "2.5"
”, the density of the hard copy image is 1.
It can be estimated that it is 0 [Macbeth]. Graph data CD
is stored in ROM211 in advance. The first cPU 201 refers to the data in the ROM 2 1 1 and calculates the estimated density ID of the hard copy image to be applied in the copying operation based on the output voltage ■P of the photosensor 19.
Calculate. That is, the density of the hard copy image that will be viewed by the operator is estimated based on the density of the toner image (reflectance of the toner image), which is one of the physical property values associated with the electrophotographic process. FIG. 12 is a plan view showing an example of the operation panel 100 for copying 1 mA. The operation panel 100 is divided into an operation section 219a for setting copying conditions such as the number of copies and density, and a display operation section 219b for displaying the status of each section. The operation unit 219a includes a print key 101 for starting a copying operation, and 7-segment LEDs 1, 2, . . . 9, respectively, for displaying the number of copies, etc.
Numeric keys 104 to 113 corresponding to the numerical value 0, clear/stop key 103 for canceling copy condition settings,
The up and down keys 114 and 115 for changing and setting the copy image density step by step, the density display section 116 for displaying the copy image density, etc. have been rearranged. In addition, the display operation section 219b includes a message display section 117 consisting of a liquid crystal display, and a key 11 for service personnel.
8 to 124 are arranged. Serviceman key 11
8 to 124 are mainly used for maintenance by service personnel, such as displaying management information stored in the RAM 210 and data processing operations, as will be described later. Note that the keys 118 to 124 for service personnel may be covered by a cover or provided within the main body so that they cannot be operated normally. FIG. 13 is a block diagram showing the general structure of the management network system 500. The management network system 5oO is a system in which five copying machines A, A, etc. of the same type as managed devices and a management device 227 are brought online using a telephone line 230.
Three of the machines are automatic exchange 225a and internal line 22
9a-c are installed in building B1 where the extension network is set up, and the other two are installed in building B2. It is installed in B3 and connected to the telephone line 230 via automatic exchanges 225b and 225c. In each of the copying machines A, A, . . . , communication processing is executed by the ICPU 201 in a timely manner, and management information indicating the operating status of each copying machine is transmitted to the service station SS. At the service station SS, the sent management information is input to the management device f227 via the automatic exchange 226. The service man! Each copy IIA manually entered into the management device 227
By displaying or printing the management information of copying machines A, A, etc., the operating status of each copying machine A, A, etc. can be confirmed. As a result, it is possible to determine whether or not maintenance is required for each copying machine A, A, . . . at a location different from the installation location of each copying machine A, A, . Next, the operation of the copying machine A will be explained according to the flowcharts shown in FIGS. 14 to 21. FIG. 14 is a main flowchart schematically showing the operation of the ICPU 201. When the power is turned on and the program starts, first,
In step #1, each part is initialized, and in step #2, an internal timer is set to define the length of one routine of the tcPU 201. In step #3, input processing is performed to receive signals from the operation keys of the operation panel 100, sensors, and switches of various parts. Next, image adjustment processing (step #4), warning display/copy prohibition processing (step #5), and data writing processing (
After sequentially executing step #6), data display processing (step #7), and data transmission processing (step #8),
In step #9, a copying operation is performed. In the next step #10, communication processing with the second CPU 221 is performed. After executing these processes, an internal timer is waited in step #l1, and the process returns to step #2. As a result, the length of the l routine is kept constant, and the processes from step #2 to step #1l are repeated while the power is turned on. FIGS. 15(a) to 15(d) are flowcharts of the image adjustment process in step #4 described above. This routine sets the settings for each device around the photoreceptor drum 5 based on a self-diagnosis that determines whether the operating state of the copying machine A is a proper state, an improper state, or an abnormal state. Setting processing for image adjustment to be performed (state "1" to stage rl5J), and state storage processing (state "16" to state r22) for storing state data indicating the state of each part obtained by self-diagnosis. It is organized from In this routine, the state is first checked in step #101, and the following processing is executed depending on the state. In state "l", the current T/C level is read from RAM209 in step #l11. Next, check whether the T/C level is "l", that is,
Check whether the standard T/C level is set (step #112L, if yes, step #l1
3 sets the state to "2". If no in step #1l2, step #113 is executed after setting the T/C level to rlno in step #1l4. In state "2", in step #l21, the charger 6 is turned on to rotate the photosensitive drum 5, and the H
The dark potential vO is measured at each HV level "1" to "9" by changing the V level sequentially. In step #L22, the measured value in step #121,
In other words, the value of the output voltage VD of the surface electrometer 90 is the dark potential V
Select the HV level "X1" (one of Hv levels "1" to "9") that is closest to 3.25 volts, which corresponds to the standard value of O (650 volts). Then, the state is set to "3" (step #123). In state "3", in step #13l, the HV level rxl selected in the previous state "2" (7)
Check whether the output voltage VD(7) value "vDX1" is 2.0 volts or more. That is, it is checked whether the dark potential vO is equal to or higher than the lower limit value (400 volts) that enables the copying operation. If YES in step #131, the HV level "X1" is set as a temporary IV level in step #132. If the answer in step #131 is NO, a serious malfunction (trouble) such as a disconnection of the charge wire 61 of the charger 6 has occurred, and the copying operation cannot be performed.
In other words, the operational state of copy vaA is abnormal. In this case, the state is set to "21" (step #1
34). In state "4", the slider unit 24 of the optical system 20 is stopped at the above-mentioned adjustment position Y1 (step #141L state is set to "5" (step #1)
142). In "state r5", first, in step #tSt, the EXP level is sequentially changed and the adjustment seal 25a is irradiated, and the bright potential V at each EXP level "1" to "9" is
Measure R. Next, in step #152, the value of the output voltage VD of the surface electrometer 90, which is the measured value in step #151, is the value closest to 0.35 volts, which corresponds to the standard value (70 volts) of the bright potential VR. Select the EXP level "x2". And set the state to "6" (
Step #1 5 3). In "state r6", in step #161, it is checked whether the value "VDx2" of the output voltage VD at the EXP level "x2" is 0.75 volts or less. That is, it is checked whether the bright potential vO is below the upper limit value (150 volts) that enables the copying operation. If the answer in step #161 is NO, a problem such as a failure of the exposure lamp 21 has occurred, and the copying operation is impossible. In other words, the operating state of copying machine A is abnormal. In this case, move to step #166 and set the state to "22". If YES in step #161, in step #162, EXP is set as a temporary EXP level.
Set level rx2J.

In the following step #l63, the actual measurement value rVDx2 is 0.5.
Determine whether the voltage is 5 volts or less. Step #l6
If 3 is YES, it is possible to set the developing bias VB that satisfies the above equation (1), and it is possible to form a copy image of appropriate image quality. The operating state of copying machine A is proper. In this case, in step #l64, change the state to "
7”. If No in step #163, it is possible to execute the copying operation, but it is impossible to set the developing bias VB that satisfies equation (1) even if the VB level "9", which is the adjustment limit, is selected. Therefore, the image quality of the copied image may be inappropriate. Therefore, copy! The operating state of IA becomes inappropriate.

In this case, the state is set to "18J" (step #1
65). In state "7", electrophotographic process condition 1
A developing bias VB is determined. That is, the value ``v'' of the bright potential VR corresponding to the above-mentioned actual value ``rVDx2''
Rx2' is calculated, and the target {direction of the developing bias VB is 'V
Rx2+150" VB level closest to BoJ Reto"
x3” (step #171), and set the VB level “x3” as the VB level (step #172)
．． For example, if the actual measured value rVDx2 is 0.35 volts, the corresponding bright potential VR value rVRx:
IJ is the optimum value of 70 volts (see Figure 9), and 22
The VB level "5" (see Figure 1O) is set with the target value being 0 (70+150) volts. Then, in step #173, the state is set to "8". In state r8J, first, in step #181, the value rV of the developing bias VB at the VB level rx'3'' is determined.
Bx3'' into equation (3) to obtain the target value rV of the dark potential vO.
Calculated value of output voltage VD corresponding to Ox4J "vDx4"
Calculate. Next, in step #182, the value rVBx3
” into equation (2) to obtain the target value “Vi
Calculate the calculated value rVDX6J of the output voltage VD corresponding to "x6". Then, in step #l83, change the state to r9.
Let it be J. In "state r9", select the HV level "x5" whose measured value (value of output voltage VD) at step #121 of the above-mentioned state "2J" is closest to the calculated value rVDx4 (step #191), and change the state. Set it to "lO" (step #192). In state "10", first, in step #201, it is checked whether the actual dark potential V○ is within an appropriate range determined according to the calculated target value. That is, the actual measured value rVDx5 of the output voltage VD corresponding to the HV level "x5" and the calculated value rVDx4.
” is checked to see if it satisfies the following equation (4). VDx5≧VDx4-0.25 [V] - (4) Note that a difference of 0.25 volts in the output voltage VD becomes a difference of 50 volts when converted to the surface potential VH. If YES in step #201, the dark potential VO is appropriate, so the HV level "x5" is set as the HV level (step #202), and the state is set to "11" (step #203). If no in step #201, the state is set to "14" in step #204. In this case, the dark potential vO is lower than the appropriate value, and the operating state is inappropriate. If a copying operation is performed in this inappropriate state, the amount of toner adhesion is small and a pale image appears. In state "lIJ", the slider unit 24 is stopped at adjustment position Y2 (step #211), and the state is set to "12" (step #212). In state "12", first, step #221 is set.
Then, the EXP level is changed sequentially and the adjustment seal 25b is irradiated, and the gray potential V1 at each EXP level "l" to "9" is measured.Next, the measured value in the previous step #221 is The value of the output voltage VD is the above calculated value rV
Select the EXP level "x7" that has the closest value to "Dχ6" (step #22 1), and set E as the EXP level.
Set the XP level "x7" (step #222).
Then, in step #223, the state is set to "13". In state rl3J, in step #23l, the actual gray potential vI is set to the calculated target value rVlx.
6, a value within the appropriate range determined according to H (Vix6 upper 10
bolt). In other words, EXP level "
It is checked whether the relationship between the measured value rVDx7'' and the calculated value rVDx6'' of the output voltage VD corresponding to 'x7' satisfies the following equation (5). V D x6-0.05≦V D x1≦V D x6
+0.05 [V] (5) If YES in step #231, the gray potential vO is appropriate, and the process advances to step #232 to set the state to "1".
6". If the answer is NO in step #231, the delay potential vO is inappropriate, and the state is changed to "17" in step #233.
Suppose that State "14" is executed when it is determined that the dark potential vO is inappropriate in the above-mentioned states rlO,,+. In step #241, it is checked whether the charger flag FCN indicating the cleaning state of the charge wire 61 is "OJ". If YES in step #241, the charge wire 61 has not been cleaned and it is dark. The cause of the inappropriate potential VO is considered to be dirt on the charger 61.Therefore, in step #242, cleaning of the charge wire 61 is performed.After that, in step #24
3, set the charger flag F'cx to "l",
In step #244, the state is set to "2". Therefore, if step #24l is YES, clean the charger 61 and try again in state "2".
” and subsequent processes are executed. If the answer in step #241 is NO, even though the charge wire 61 has already been cleaned, the appropriate dark potential V
This is the case when O cannot be obtained. In this case step #
In step #245, the state is set to "15J." In state "l5," first, step #251
Then, it is checked whether or not the T/C level change failure n is "3". If no in step #25l, step #252
Proceed to and increase the T/C level by one level. That is, T/C is adjusted so that the toner weight ratio T/C becomes large.
Change the level settings. For example, if the current settings are T/C
If the level is "l", change it to the T/C level "2".
Next, in step #253, the number of changes n is set to the current value by 1.
In step #254, the state is set to "8".
”. Therefore, if step #25l is NO, the seventh
As shown in the figure, the target values of dark potential vO and gray potential ■i corresponding to the new T/C level are calculated, and based on the target values, the HV level and The EXP level will be set. If step #251 is YES, it means that the T/C level "4" is set as the T/C level, and the T/C level has already reached the adjustment limit, so change the T/C level. is not performed, and the state is set to "l9" in step #255. In state "16", in step #26l, it is checked whether the number of changes n is "0". If YES in step #26l, T/
Since the standard T/C level "1" is set as the C level, in step #262, status data C indicating that the T/C level is appropriate. ．． Remember. Storage in this routine is performed by storing data in the RAM 209. If the answer at step #26l is NO, then at step #264, the status data C? indicating that the T/C level is inappropriate? I admire /C. Step #
After execution of step #262 or step #264, step #2
Set the state to ``20'' at 63. In state "l7", step #27? Then, it is checked whether the number of changes n is r■, and if yes, state data cvi indicating that the gray potential VI is inappropriate is stored (step #272), and if no, the state data cvi is stored. , state data C
v! and state data CT,, (step #
273). After executing step #272 or step #273, proceed to step #263 described above. Stay-1-r
In l8J, state data CvI1 indicating that the bright potential VR is inappropriate is stored (step #275),
Proceed to step #263 above. In state rl9J, state data Cv0 indicating that the dark potential VO is inappropriate is stored (step #2
7 6) Proceed to step #263 above. In state "20", processing for estimating the density of the hard copy image based on the electrophotographic process conditions set as described above is executed. That is, in step #281, the toner image formed by turning off the exposure lamp 21 (toner image corresponding to black color) is formed, and the toner image formed by turning on the exposure lamp 21 at adjustment position Y1 (toner image corresponding to white color) is formed. The photosensor 19 is used to measure the densities of three types of toner images: a toner image (a toner image corresponding to gray), and a toner image formed by turning on the exposure lamp 21 at the adjustment position Y2 (a toner image corresponding to gray). Next, in step #282, an operation is performed to obtain the estimated density ID of the hard copy image based on the output voltage ■P of the photosensor 19 and the graph data GDI stored in the ROM 211, and , estimated density data 1 for each of the three types of gray hard copy images.
0. , ID. ID1 is calculated. Then, in step #283, an image adjustment completion flag FC is set to "1" to indicate that settings for each device around the photosensitive drum 5 have been completed. In state r21J, in step #29l, state data CCH indicating that the charger 6 is in an abnormal state is stored based on the self-diagnosis in state "3" described above. Then, in step #292, the image adjustment completion flag FC is set to "1". In step #22J, based on the self-diagnosis in state "6" described above, state data ctxr indicating that the exposure lamp 2l is in an abnormal state is stored (step #2
93), proceed to step #292 above. FIG. 16 is a flowchart of the warning display/copy prohibition process in step #5 of FIG. 14. In this routine as well, first check the state in step #301,
The following processing is executed depending on the state. In step }'31J, in step #311, it is checked whether the signal S1 is input. The signal Sl is the up key 114 or the down key 115 on the operation panel 100.
is input to the ICPU 201 via the interface 216 when the button is pressed. If no in step #311, is it su? In step #3l5, set the state to "32". If step #311 is YES, this means that the operator has set the density, which is one element of image quality. In this case, the operator is considered to be paying particular attention to image quality. Therefore, when the operating state of copying machine 8 is inappropriate, the
It is necessary to inform the operator that it is difficult to form a copy image of the desired quality. Therefore, in steps #3l2 to #314, it is checked whether the status data C■+Cw*+Cv* are stored, that is, whether each data is in the RAM 209. If YES in any of steps #312 to #314, the operating state of copying machine A is inappropriate. In this case step #31
Proceed to 6. In step #3l6, a warning is displayed on the message display section 117 of the operation panel 100 to the effect that the operating state of the copying machine A is inappropriate. Figure 22(a)-(
k) is the message display section l? 7 is a diagram showing an example of a display screen of No. 7. FIG. 22(a) shows the display screen when the answer is YES in step #312, and the message ``rev+J'' indicating the inappropriate location is displayed together with the message Z1 in case of an inappropriate state. Step #313
, 314, the characters rC■1 and 'Cv*J are also displayed together. In state "32", first step #321
Then, it is checked whether or not the state data CCN is stored, and if it is stored, in step #322,
A warning display for abnormal conditions as shown in Fig. 22(b) is displayed.
In this case, the characters rCc and IJ indicating the trouble location (abnormal location) are displayed together with the message Z2 in case of an abnormal state. Next, in step #323, a copy prohibition process is executed to prohibit the start of a copy operation. That is, the operation panel 100
It prohibits input from each of the keys 101, 103 to 115, and performs control to turn off the power of each section except for devices related to data processing. Thereafter, in step #324, the state is updated to "33". In state "33", first step #331
Then, it is checked whether or not the status data CtXP is stored, and if it is stored, a warning of the abnormal state shown in FIG. 22(C) is displayed in step #332. In this case, the characters 'CtxpJ' will be displayed to indicate the location of the problem. Note that step #322 has already been completed at this time.
If the 'CcwJ warning is displayed,'
C Below CMJ 'C! The characters IFJ are displayed. In step #333, a copy prohibition process similar to that in step #323 described above is executed, and in step #334, the state is returned to 131''. 17(a) to (C) are flowcharts of the data writing process in step #6 of FIG. 14. In step #401, the state is checked, and the following processing is executed depending on the state.

In state "41", first, step #411
Then, the write end flag FRA indicating the end of this routine is set.
Determine whether M is "0" or not. Step #411
If no, write end flag FRAM
If is "1", immediately return to the main routine. By executing step #411, each subsequent process will be executed only once after the above-described image adjustment process. If YES in step #41l, step #4l2
Then, it is checked whether the image adjustment completion flag FC is "O". If the answer in step #412 is NO, that is, if the image adjustment end flag FC is "1", in step #413 the image adjustment end flag FC is set to "OJ" and the step #414
Proceed to. In step #414, date and time data TD indicating time information such as date and day of the week is read from the second CPU 221. Thereafter, the write end flag FRAM is set to "1" (step #415), and the state is set to "42" (step #416). In state r42J, in step #421, state data Cv! is stored in RAM 209. Check whether it is memorized. If step #421 is YES, step #422
Then, as will be described later, number data k1 indicating the number of times the date and time data TD was written to the RAM 210 in response to the inappropriateness of the gray potential Vl is read from the RAM 210. Next, "r1" is added to the value of the read count data k1 to obtain new count data kl (step #423), and the new count data k1 is written to the RAM 210. Subsequently, in step #425, the above-mentioned step #424 is performed.
Write the date and time data TD read in step #42 into the RAM210 in association with the status data CVI.
6, update the state to "43". In state “43” to state “47”? , each state data cyzc + CVl + C'I
'h+CCM. State “42” corresponding to C■2
The same processing is performed. That is, the state data CT/C in RAM209
I Cwt. Check whether Cv*+ CCNI Czxp is stored (steps #431, 441, 451
, 461, 471), readout of count data k2 to k6 (
Step #432, 442, 452, 462, 472)
, update of number data k2 to k6 (steps #433, 44
3,453,463,473), write count data k2-6 (step #434,444,454,464)
, 474), writing of date and time data TD (step #4
35,445,455,465,475), state update (step #436,446,456,466,4
76) is executed. In Step }'48J, the processing number data N indicating the number of times the image adjustment process has been executed is read from the RAM 210 (step #481), and the value is updated by adding "1" to the processing number data N (step #4). 82) Write the updated processing count data N to the RAM210 (step #483) and set the state to "49" (step #484). In step }r49J, in each step from step #491 to step #495, the state data COi Cvt+ Crze + Cw+++
It is checked whether each Cva is stored in the RAM 209. If none of the state data is stored, the state is set to "50" in step #496. If the answer is YES in any of steps #491 to #495, in step #497, management data CDI for checking changes over time in the operating state of copying machine A is sent to RA.
Write to M2 1 0. The management data CDI includes the date and time data TD, the status data determined as YES in steps #491 to #495, and three types of surface potentials VH (dark potential vO, gray potential Vl, Final measurement value of bright potential VR), each setting level (V
B, T/C, HV, EXP), and estimated concentration data I
D. ,10! , ID. Consists of. In step }r50J, it is checked whether the state data Cc, I is stored (step #501), and if YES, the management data CD2 is written to RAM2 1 0 (step #5 0 2), and the state is set to "51" (step #503). The management data CD2 includes date and time data TD,
It consists of status data CCN, the final measured value of the dark potential vO measured after the end of the image adjustment process, and the HV level. In state "5l", state data C is stored in RAM 209.
Check whether tMP is stored (step #511L) If yes, write management data CD3 to RA.
Write to M2 1 0 (step #512) and set the state to "52" (step #513). Management data CD3 includes date and time data TD, status data Ct
Final measured values of dark potential VO and bright potential VR, HV level and EX measured after completion of IIF SH image adjustment process
Consists of P level. In this way, the management data CD1 to CD3 are designed to contain the minimum information that makes it possible to identify the cause of the inappropriate operating state of copying machine A. The content items differ depending on whether it is inappropriate. This makes it possible to reduce the capacity of the RAM 210, simplify the display described later, and improve the efficiency of data transmission to the management device 227. In states "52" to "54", processing related to periodic data erasure or data initialization is executed to improve the memory usage efficiency of the RAM 210. In state "52", first, step #521
The management data CDs 1 to 3 written in the past are stored in RAM.
Read from 2 1 0. Next, in step #522,
It is determined whether the read management data CDs 1 to 3 were written on a specific day of the week, for example, Monday (referred to as "Monday's data", hereinafter the same). If YES in step #522, step #525
Then, determine whether the date is within the past two months. If YES in step #525, the data is not erased and the state is updated in step #526. If the answer is NO in step #522, it is determined in step #523 whether or not it is within the past week. If YES in step #523, proceed to step #526. If no in step #523 or step #525, in step #524, unnecessary management data CD1 to
Execute the deletion in step 3. As a result, only the daily data within the past week and the data from every Monday within the past two months are stored in RAM2 1.
It will be stored as 0.

In state "53", first, the above-mentioned state
42J - In state "47", the date and time data TD written in association with each state data is read from the RAM 210. Next, in step #532, it is determined whether or not it is within the past year. If YES in step #532, the data is not erased and the state is updated in step #534. If no in step #532, unnecessary date and time data TD is deleted in step #533. As a result, only the date and time data TD within the past year will be continuously stored in the RAM 210. In state "54", it is checked in step #54l whether the signal S2 is input. The signal S2 is generated when the serviceman key 118 is pressed and when the initialization control signal S2 is sent from the management device 227 to the copier A.
is input to the I-th CPU 201. If no in step #541, the state is returned to "4l" in step #543. If no in step #541, in step #542, the values of the number of times data k1 to k6 and the number of processing data N are initialized to "0", and the process proceeds to step #543. 18(a) to 18(d) are flowcharts of the data display processing in step #7 of FIG. 14. First, in step #601, the state is checked, and the following processing is executed depending on the state. In state "61", in step #611, the processing flag FS3 indicating the execution progress of this routine is "0".
Check whether it is. If no in step #61l, move to step #616 and change the state to "62".
”, and if YES, proceed to step #612. In step #6l2, it is checked whether the signal S3 is input. The signal S3 is manually input to the ICPU 201 when the serviceman key 119 is pressed. Step #
If 612 is YES, proceed to step #613; if NO, proceed to step #6l6 described above. In step #613, today's data (the day the routine is executed) among the management data CD1 to CD3 is read from the RAM 210, and the data is displayed on the message display section 117.

FIGS. 22(d) and (g) show screens displayed based on the management data CDI corresponding to the proper state and improper state, respectively, and FIGS. 22(e) and (f) show the management data CD2 and FIG. This shows the screen displayed based on CD3. In these figures, 301 is the date, 30
2 is a character corresponding to the status data, 303 to 305 are each final measurement value, 306 to 309 are each set level value, and 310 is an estimated concentration value. Next, in step #614, an identification symbol 300, for example, a black triangular mark as shown in FIGS. 22(e) to 22(g), is displayed near the display character corresponding to the inappropriate item on the display screen. ．． This allows you to easily check whether each item is appropriate or inappropriate. In step #6l5, the processing flag FS3 is set to "1". In states "62" to "68", the value of the processing flag FS3 and the signal S are the same as in state "62".
The presence or absence of the input in step 3 is checked. Also, from the management data CDs 1 to 3, the previous day, 2 days ago, 3 days ago...6
The data from the previous day and 7 days ago will be read and displayed.
Identification symbol 300 is attached to invalid items. In other words, each time the serviceman presses the serviceman key 119, the displayed management data CD1 to CD3 change to the one from the previous day. Further, when the data from seven days ago is displayed, if the key 119 is pressed again, the data from the current day will be displayed again. In state '69J, step #
At 65l, the presence or absence of input of signal S4 is checked. Signal S4 is the clear/stop key 103 or key 119
This is input when any of the serviceman keys 118 and 120 to 124 other than 124 are pressed. If YES in step #651, set the processing flag FS3 to "0" in step #652.
Return to . With this, for example, clear stop key 1
By pressing 03, the display of management data CD1 to CD3 can be stopped. Furthermore, by pressing the clear/stop key 103 and then pressing the serviceman key 119, even if the display is from 2 to 7 days ago, it can be immediately changed to the display for the current day. In state "70", in step #661, it is checked whether the processing flag FS5 is "O". If no in step #661, move to step #666 and update the state to "71"; if yes,
Proceed to step #662. At step #662, the signal S
Check the presence or absence of input in step 5. The signal S5 is input when the serviceman key 120 is pressed. If YES in step #662, proceed to step #663; if NO, proceed to step #666 described above. In step #663, one of the management data CDs 1 to 3 is
The information on the previous Monday is read from the RAM 210 and displayed on the message display section 117. Next, in step #664, the above-mentioned identification symbol 300 is placed near the display character corresponding to the inappropriate item on the display screen.
Display. In step #665, the processing flag FS5 is updated to "1". In states "71" to "78J", the value of the processing flag FS5 and the signal S are the same as in state "70".
The presence or absence of input in step 5 is checked. Also, from among the management data CDs 1 to 3, data from each Monday of one week ago, two weeks ago,...eight weeks ago are read and displayed, and identification symbols 300 are given to inappropriate items. It will be attached. In other words, each time the serviceman presses the serviceman key 120, the displayed management data CD1 to CD3 are replaced with those from one week ago. Further, when the data from eight weeks ago is displayed, if the key 120 is pressed again, the data from Monday, one week ago will be displayed again. In state "79", the presence or absence of input of signal S6 is checked in step #691. The signal S6 is input when the clear/stop key 103 or any of the serviceman keys 118, 119, 121 to 124 other than the key 120 is pressed. If YES in step #69l, the processing flag FS5 is returned to rQJ in step #692. As a result, for example, clear stop key 103
The display of management data CDs 1 to 3 can be canceled by pressing . In step }'80J, in step #701, the presence or absence of input of signal S7 is checked. The fi number S7 is input when the serviceman key 121 is pressed.
If NO in step #70l, the process moves to step #703 to update the state, and if YES, the process moves to step #702. In step #702, the number data k1 to k6 and the processing number data N are read from the RAM 210, and the read data is displayed on the message display section 117. FIG. 22(h) shows the display screen in the process of step #702. In the same figure, 313~? 19 is a number indicating the value of the number of times data k1 to k6 and the number of processing data N, respectively. Further, 3l1 is the year and date when data k1 to k6 and N were initialized and counting of these data started. In state r81J, the presence or absence of input of signal S8 is checked in step #7l1. The signal S8 is input when the serviceman key 122 is pressed. If NO in step #7l1, the process moves to step #713 to update the state, and if YES, the process moves to step #712. In step #7l2, the state data CV! corresponding to the inappropriate state and abnormal state! , CT/C, Cw++.
C. ,Cc■C! Displays XF and the dates they were memorized in chronological order. FIG. 22(1) shows the display screen in the process of step #7l2, and 400 in the figure is the date (month/day) when each status data was stored. Step} In ra2J, in step #72l,
Check whether signal S9 is input. The signal S9 is input when the serviceman key 123 is pressed.
If NO in step #72I, the process moves to step #723 to update the state, and if YES, the process moves to step #722. In step #722, the processing flag FS9 is set to "l". In state "83", it is checked in step #731 whether the processing flag FS9 is "0", and if YES, the process moves to step #759 to update the state. If no in step #73l, that is, if the serviceman key 123 is pressed, step #732
~In step #739, the presence or absence of input of signals 521 to 28 is sequentially checked. Signals 321-28 and a signal S29 to be described later are input in response to operations on the numeric keys 104-112. If YES in steps #732 to #739, the process proceeds to steps #751 to #758, respectively. In steps #751 to #758, the dark potential vO, gray potential Vi, bright potential VR, VBli bell, T/C level, HV level, E
Graph XP level and estimated concentration ID in time series (7
(schematized) and displayed on the message display section 117. As a result, service personnel can check the past
Weekly changes in operating status can be confirmed on W1. Second
2tlN) shows the display screen at step #75l. In the figure, 320 is a horizontal line indicating the optimum value of the dark potential VO, 321 and 322 are horizontal lines indicating the upper and lower limits of the appropriate range, and 323 to 329 are days (today, the previous day...
6 days ago), 330 to 336 are the dark potential v of each day
This is a plot showing OO values. In the example of FIG. 22(j), the dark potential vOO value was at its optimum value six days ago, but has gradually decreased since then and has fallen below the lower limit today. Therefore, an identification symbol 300 is displayed above the vertical line 323. If all the answers in steps #732 to #739 are negative, the presence or absence of input of signal S29 is checked in step #740. Signal S29 is clear/stop key 103
and keys 118 to 12 for service personnel excluding key 123
It is input when 2,124 is pressed. If YES in step #740, step #741
Then, the process flag FS9 is reset to "O" and the process moves to step #759 described above.

In state "84", in step #761, the presence or absence of input of signal SIO is checked. The signal S10 is
It is input when the serviceman key 124 is pressed. If no in step #76l, return to the main routine. If YES in step #761, the processing flag FSIO is set to “1” in step #762, and
In step #763, the state is updated to "85". In state "85", in step #771, it is checked whether the processing flag FSIO is "0",
If yes, move to step #799 and return the state to "6l". If the answer in step #771 is NO, that is, if the serviceman key 124 is pressed,
Similarly to state "83", in steps #772 to #779, the presence or absence of human power at signals 321 to 28 is sequentially checked. If YES in step #772 to step #779, step #79l to step #79 respectively.
Proceed to step 8. In steps #791 to #79B, the dark potential ■0, gray potential vl2 light potential VR%VB level, T/C level, HV level, EXP level, and estimated concentration ID are calculated on each Monday of the past two months. It is graphed in series and displayed on the message display section 117. As a result, service personnel can check the past two months (
It is possible to check changes in the operating status over a period of 8 weeks). FIG. 22(k) shows the display screen at step #791. In the same figure, 320 to 322 are shown in Figure 22 (J).
The horizontal lines 342 to 349 are similar to the above, vertical lines 342 to 349 indicate weeks (this week, last week, the week before last, etc.), and 359 to 366 are plots indicating the values of the dark potential VO for each week. If all of the answers in steps #772 to #779 are NO, the presence or absence of input of signal S30 is checked in step #780, and if YES, the processing flag FSIO is reset to "0" in step #781. Proceed to step #799 above. Note that the signal S30 is a signal that is input when the serviceman keys 118 to 123, excluding the clear/stop key 103 and the key 124, are pressed. FIG. 19 is a flowchart of the data transmission process in step #8 of FIG. 14. In this routine, corresponding management information is sent to the management device 227 at a predetermined time for each self-diagnosis item, depending on the need for management of the operating state of the copying machine A. First, in step #901, the state is checked, and the following processing is executed depending on the state. In state "91", first, in order to check whether it is the time (day of the week, time) to transmit data, the signal S is sent in steps #91l to #913, respectively.
Check the presence or absence of input from ll to 130 in sequence. Signal S1
1.512 is input from the second CPU 22l at a predetermined time as will be described later, and the signal 313 is input when a control signal instructing data transmission is applied from the management device 227. If yes in step #9l1, step #915
If no in step #911 and yes in step #9l2, proceed to step #914. If step #9l3 is NO, that is, the signal S1l
If none of the steps 1 to 13 have been input, the process moves to step #920 to update the state. In steps #914 to #918, the results of each self-diagnosis item are checked. That is,
State data C@K+ corresponding to proper and incorrect states
Cvz+C? /C + Cwm+ Determine whether Cva is stored. If YES in any of steps #914 to #918, step #9
Proceed to step #920 if both are no.
Move to. In step #919, the above-mentioned management data CDI is transmitted to the management device 227 via the online controller 223. In other words, by executing this state "91", if there is an inappropriate item, management information is sent to the management device 227 at 10:00 a.m. every day regardless of the day of the week, but if there is an inappropriate item. If not, management information will be sent every Monday and Thursday at 10am. Step } In r92J, step #921
Then, it is checked whether the state data Ce, I are stored, and if no, the state is updated (step #923) and the process returns to the main routine. If YES in step #921, the management data CD2 is sent to the management device 227 in step #923. In state "93", it is checked in step #931 whether state data CIIIF is stored, and if no, the state is updated (step #931).
933), return to the main routine. Step #
If YES in step 931, the management data CD3 is sent to the management device 227 in step #923. In other words, state "92J" and state "93" are processes for dealing with an abnormal state, and in an abnormal state, data indicating the contents of the abnormal state is managed regardless of the date and time and the presence or absence of an instruction from the management device 227. The data is sent to the device 227. As a result, maintenance work can be carried out quickly and the downtime (failure time) of copying machine A can be shortened. FIG. 20 is a main flowchart schematically showing the operation of the second CPU 221. When the program starts, initialize each part (step #51) and set the internal timer (step #52)
, input processing (step #53), time measurement processing (step #53),
54), and then, in step #55, communication processing with the ICPU 201 is executed. After executing these processes, an internal timer is waited in step #56, and the process returns to step #52. In addition, the second
The CPU 221 is backed up by a battery, and the clock function is maintained even when the main body power is turned off. FIG. 2l shows the I CPU 201 in step #55 mentioned above.
In this routine, which is a flowchart of communication processing with , the state is first checked in step #61, and the following processing is executed depending on the state. In state "101", in step #62, date and time data TD indicating the current date, day of the week, and time is transmitted;
In step #63, the state is set to "l02". In state rl02J, it is checked in step #7l whether the current time is, for example, 10:00 am (AMIO:00), and if no, the state is returned to rloIJ in step #76. If step #71 is YES, that is, it is 10 o'clock in the morning, then step #72 determines whether or not it is Monday. If it is not Monday, then in step #73 it is determined whether it is Thursday. Based on these judgments, if today's day of the week is Monday or Thursday, the state is
The state is set to l04J (step #75), and in the case of other days of the week, the state is set to rl03J (step #74). In "state rl03", in step #81, the ICP
Send signal 311 to U201. In other words, the signal Sl1
will be sent on any day of the week other than Monday or Thursday. After executing step #81, the state is returned to rl01 in step #82. In state rl04J, a signal 312 is transmitted to the th ICPU 201 in step #91. In other words, the signal S12 will be transmitted when today is Monday or Thursday. After execution of step #91, step #
At 92, return the state to rl01J. In the above embodiment, predetermined management information is stored in the management device 22.
7 can be arbitrarily selected depending on the actual management situation. In the above embodiment, the management information that is generated daily is stored in the fixed RAM 210, but it is also possible to store this management information using a storage medium that is removable from the copying machine A, such as an IC card. You may also do this. In that case, it becomes possible to analyze the condition of Copy IIA using a dedicated data processing device carried by a service person for maintenance purposes. [Effects of the Invention] According to the invention as claimed in claim 1, it is possible to efficiently identify the cause of changes in the image quality of hard copy images, and to maintain appropriate image quality while reducing the storage capacity of the storage means and suppressing the cost increase of the device. It becomes possible to take appropriate measures to obtain the desired results. According to the invention of claim 2, in addition to the above-mentioned effects, there is no need to separately prepare a dedicated management information reading device I, and not only service personnel but also users can easily read management information as needed. can be recognized.

[Brief explanation of drawings]

Figure 1 is a cross-sectional front view showing the main parts of the copying machine, Figure 2 is an enlarged view of a part of the optical system, Figure 3 is a diagram showing the structure of the output circuit during charging, and Figure 4. The figure shows the setting level during charging, Figure 5 is a block diagram of the control circuit of the copying machine, Figure 6 is a graph showing the relationship between toner weight ratio and toner concentration sensor output voltage, and Figure 7 is a graph showing the relationship between toner weight ratio and toner concentration sensor output voltage. Figure 8 is a graph showing the relationship between the weight ratio setting level and dark potential and gray potential. Figure 8 is a graph showing the relationship between the output voltage of the photosensor and estimated density. Figure 9 is the graph showing the relationship between the photoreceptor drum surface potential and the surface electrometer. A graph showing the relationship between output voltages, Figure 10 is a diagram showing the current copying bias setting level, and Figure 11 is a graph showing the relationship between output voltages.
12 is a plan view showing an example of the operation panel of the copying machine; FIG. 13 is a block diagram showing the general configuration of the management network system; FIGS. 14 to 21. 22 is a flowchart showing the operation of the copying machine, and FIGS. 22(a) to 22(k) are diagrams showing an example of the display screen of the message display section. 80... Toner concentration sensor (sensor means), 90
... surface electrometer (sensor means), 117 ... message display section (display means), 201 ... th ICPU (
process control means), 210...RAM (storage means), 221...second CPU (timekeeping means), CD1~
3... Management data (management information), A... Copying machine (image formatting device). Figure 3

Claims (2)

[Claims] (1) An image forming apparatus that forms a hard copy image using an electrophotographic process, comprising a sensor means for measuring physical property values associated with the electrophotographic process, and a control of the electrophotographic process based on the output of the sensor means. a storage means for storing at least one of a process setting value set by the process control means and a measurement value by the sensor means as management information; and a clock means for generating date information and time information. . An image forming apparatus, wherein the management information is deleted when a preset storage period has elapsed. (2) A display means was provided to display the management information. The image forming apparatus according to claim 1, characterized in that: