JPS5821264A - Image former having self-diagnosis function - Google Patents

Abstract

PURPOSE:To prevent the generation of additional troubles owing to defective parts by constituting a titled device in such a way that the self-diagnosis function is executed separately and independently from the sequence operation for the purpose of image formation. CONSTITUTION:When self-diagnosis is required, the operator operates ''0'' key of ten keys 42 in an operating part continuously >=3 times, then the mode wherein the self-diagnosis program is assigned is set, and a microcomputer muCOM controls the driving of the device in accordance with the self-diagnosis program. When the microcomputer detects a troubles as a result of the self-diagnosis, the composite displays the troubles by flickering said part and the digital information corresponding to the content, and stops the device at the point of that time. If the absence of any trouble is decided by the self-diagnosis, the absence of any abnormality is announced by flickering and displaying ''00'' and the device is stopped. Since the troubles in the various psrts of the device are detected without the operation of image formation, the generation of additional troubles by the defective parts is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus having a self-diagnosis function for detecting failures in various parts of the apparatus. Microcomputers have come to be used.

In such a device, the control signals to be output to each part of the device, the koji output timing, etc. are stored in the ROM of the microcomputer in 1pgram in advance, and during image forming operation, 110MK of the microcomputer is stored in the ROM. A control signal is output to each part of the device according to the control program, and each part of the device operates in sequence based on this control signal.

In the control system of such devices, many electrical components such as relays, microswitches, photoelectric switches, solenoids, electromagnetic clutches, and motors are controlled by the system control unit, and these electrical components are also complex. It is connected to many electrical wires that run through the path and are gathered and connected to the system control section. In order to increase system reliability under these conditions, it is of course important to use highly reliable components and to design a system that minimizes mechanical stress. This does not mean that the possibility of failure should be ignored, considering the lifespan of parts due to recycling, increased stress, etc. Therefore, in addition to efforts to improve reliability, when a major failure occurs, efforts are made to return the system 1iKll from the failure state to a normal state in the shortest possible time. As one of the countermeasures, a device 1IxII has been proposed which is equipped with a self-diagnosis function to quickly detect a malfunctioning part and notify the user. The conventionally known self-diagnosis function detects abnormal conditions during the sequence operation of image formation.For example, if a malfunction has already occurred before the apparatus is started, the apparatus may be in trouble. Nevertheless, the image forming operation is performed, and this failure is detected during the image forming operation.

In addition, since a device with a faulty part is forced to operate normally, there is a risk of further failures occurring.

In addition, when a switching member such as a microswitch is used to detect the position of a moving member, there are several reasons why the position detection operation may not be performed properly. It was difficult to distinguish and detect.

In addition, if the conventional self-diagnosis does not detect any abnormality and the device is normal, the normal O device control will automatically switch to 6 [#], and the self-diagnosis function will return to the standby state. However, this did not allow the user to confirm whether or not the self-diagnosis was performed normally.

In view of the above points, the present invention provides a self-diagnosis program for self-diagnosis, separate from the control program for controlling each part of the pupil for image formation, and when execution of the self-diagnosis program is selected. #i1 device Kll formation self # without operation! Drive control is performed using an IF program. By executing the self-diagnosis function independently of the sequence operation for image formation, failures in each part of the device can be detected in a short time, and when a failure is detected, the affected part and internal parts can be displayed and used. It is an object of the present invention to provide an image forming apparatus having a self-diagnosis function that accurately and quickly informs the user of the KIlI& condition.

Another object of the present invention is to provide an image forming apparatus having a self-diagnosis function capable of determining the status of the means for outputting signals operated by the movable member for image formation.

Still another object is to provide an image forming apparatus having a self-diagnosis function that notifies a user that the self-diagnosis has been successfully executed by displaying the completion of the self-diagnosis program.

The present invention will be further explained below based on the drawings.

FIG. 1 is a flowchart showing an outline of a control system to which the present invention is applied. In step 1, the control system starts operating, and in step 2, it is determined whether control based on the self-diagnosis program can be selected. If the selection is not possible, the process proceeds to step 3, where the apparatus is driven and controlled according to the image forming program for normal image formation. If the selection is possible, the process advances to step number and it is determined whether the designation of the self-diagnosis program has been input from the operation unit. If a self-diagnosis program is designated, the process advances to step 6 and the device is driven and controlled in accordance with the self-diagnosis program. If it is not specified, it is determined that it is not necessary to execute the program even though the self-diagnosis program is in a selectable state, and the process proceeds to step 3 according to the normal image forming program. Drive and control the device. Note that the drive control by the self-diagnosis program can be canceled by turning the power to the microcomputer 40F1.

In this manner, the present invention allows the drive control of the apparatus by the normal image forming program and the self-diagnosis program to be completely independent.

゛Then, if the self-diagnosis program detects an abnormality, numerical information corresponding to the content will be flashed on the display,
・□This allows users and service personnel to be accurately informed of the malfunctioning part and the details of the malfunction.

FIG. 2 is a sectional view of a copying machine to which the present invention is applied.

In the figure, 1#'i moves back and forth on the document table on which the original is placed, 2#
- 11i 4H, a reversible drum with a continuous image light body, a lamp for exposing the original image on the 3Fi document table l onto the drum 2, a corner charger that positively charges the surface of the 5Fi photoreceptor in advance, 6 is an exposed image 9 is a developing device that develops the electrostatic latent image, and 9 is a charger that transfers the developed image onto a transfer paper 10. A cassette that contains li#i transfer paper 10 12 is a stand for manually feeding the transfer paper 10, and is moved to the position shown by the dotted line when manually feeding paper.

15 is a roller that feeds the transfer paper 10 from the cassette 11; 14#i a roller that feeds the transfer paper from the manual feed table 12;
A register for aligning the leading edge of the 15ij transfer paper and the leading edge of the drum image; a roller for separating the 16Fi transfer i from the drum; a belt for conveying the 17#i transfer paper;
The xam fixing roller, 19, discharges the transfer paper to the tray 20, and partially, 2! 1 is a blade cleaner for removing residual toner from the tram; 4 is a container for storing the toner collected by the blade cleaner 21;
* Negative corner charger, 22#i pump 30 lens for focusing the reflected light from the drum surface on the drum surface, 23ti drum 2.11 feed belt 1f, fixing roller 1B, document table 1, etc. a motor driving the 24
Synchronous pulse generator, a5t, which generates a control tying signal synchronized with each turn of the drum to the microcomputer.
jljL Forward clutch that controls draft table 10 Sojin, 26t;
i Reverse clutch that controls the reverse movement of the document table, 2F, 28ij
The drum 2 is irradiated with light from the lamp 3 using a mirror. 8
1#'i Paper detection switch that detects the presence or absence of transfer paper 10 in cassette ll, 82 a manual feed switch that detects the position of the manual feed stand 12, 83 a separation switch that detects the separation state of transfer paper lO, 84Fi transfer A paper ejection switch that detects whether the paper 10 is normally ejected, a fixed position switch that detects whether the 55ij document table l is at the home position (the state shown in FIG. 2) or white, and a drive for the 56ij feeding roller 13. This is a timing switch operated by the document table l for obtaining timing.

Explain the operation. When the main switch is turned on, the motor that drives the drum 2 is turned on, the lamp 3 is turned on, and at the same time, the corona charger 6 is turned on and the drum is rotated.

This cleans the drum of residual toner, residual charge, and memory.

When the fixing roller 18 reaches a fixable temperature by an internal heater, a copy enable signal is generated. If the cobby switch is not turned on, the drum continues to rotate, and the drum stops when a predetermined number of kW of pulses from a synchronizing pulse generator 1i 124, which is provided in the drum drive system and generates an IL+ pulse for each rotation of the drum, is applied.

The rotation of the drum above the gate is called the first front rotation.

When the copy switch is turned on while the drum is rotating or stopped, the reverse clutch is activated and the document table 1 starts moving forward in the direction of arrow l. At the same time, the drum 2 is rotated again and after about 11i4 rotations (hereinafter referred to as the second front rotation). , the forward clutch a6 is activated, the document table 1tj starts to move backward in the direction of arrow 1, and the document on the document table starts to be slit exposed. The reflected image of lamp 30 is cell 7
Slit exposure is performed on the drum 2 through the lens 22.

The photoreceptor surface of the drum 2 is composed of an insulating layer, a photoconductive layer, and a conductive layer, and when the charge charged by the charger 5 reaches the exposed surface, the positive charge is removed by the negative charger 6 and the optical image. Ru. And when the - uniformly reaches the m-round surface, □ Mirror 2? The light forms a contrasting electrostatic latent image on the five faces of the drum. The composition is development II8
The toner is applied to the transfer paper 1 at a positive potential of -9.
Transferred to 0.

The transfer mxo is one sheet separated and fed from the cassette 11 by the timing operation of the paper feed roller 13, and is further passed through the transfer area by the registration roller 15 at the same speed as the rotation of the drum. After the transfer, the transfer paper 10 #i is separated by a roller 16, sent to a fixing roller 18 by a belt f, where the image is fixed, and then discharged onto a tray 20 by a roller 19. Dofu five strokes after the transfer is completed.

Subsequently, it is cleaned by a gamma laser 21, static electricity is removed by a charger, and the memory is removed by light from the lamp 3 through a mirror 28.

When making continuous copies from the same original, the original table l is reciprocated as many times as the number of copies set using the numeric keypad of the copying machine operation section.

In the case of manual paper feed, the user moves the multi-hand feed table 12 to the position shown by the dotted line (manual feed position) K##, and the manual feed switch s2 detects this and becomes the manual paper feed standby soft section. In this state, the transfer paper inserted from the manual feed table 12 is sent to the registration roller 18 by the feeding μm channel 14.

The subsequent operation is the same as in the case of paper feeding from a cassette.

However, if the paper feed tray 12 is set to the manual feed position, paper feed from the cassette 11 is prohibited.
040ij is a plan view of the operation unit of the copying machine shown in the figure. Copy start key - 141#i Stop key to interrupt continuous copying, 42#i Ten key to store failure in memory to set the number of continuous copies. Clear key to clear the number of memories, 44 is the copy shading set lever 14
Is 5 the number of memory O? The segment display displays numerical information set using the numeric keypad 42 and numerical information indicating a failure state based on the self #jlIIli function. No. 6d is a wait lamp that lights up until the fixing roller 18 reaches a fixable temperature, No. 4 is a lamp that is used to indicate the cassette and no transfer paper in the cassette, and No. 48 is a lamp that displays used toner by the blade tarner 21. This lamp is displayed when the toner in the container 4 is full. 49 is displayed when the sheet is jammed. When jamming, clear key 43, numeric keypad 4
1 does not operate, but the numeric keypad and clear key can be operated during the wait. Segment display 45#i, when the power switch (not shown) is turned on, zero suppressed l is displayed beautifully during the wait, Each time l copying is completed, the number subtracted by 1 from the set number is displayed, and when the set number has been copied, the set number is displayed again, and after 30 seconds have elapsed without starting copying, l is displayed again. As a result, 1 copy is 10! ? Copying can be started without having to set several copies using -41, and copies can be executed smoothly.

9x B) Display [t4aFi blinks when the power switch is turned on, but if the temperature of the controller falls below the fixable density and it is 1 to 1, that is, the previous operator turned on the power switch and the leap 1 If the density is lower than the fixable density (Way), it will blink. Further, when the temperature of the fixing roller rises to a temperature that allows fixing and the wait time has elapsed, 1 is lit. When the power source switch is turned off, the blinking 1 light disappears and the power is turned off, indicating that the power is off.Furthermore, when the copy key 40 is turned on after the way shift, the long 1 blinking operation of the point reduction interval during wait shifts to the 1st rotation mode. Do it until it's done. In other words, one weight display can display the following four states: power-on state, weight standstill that cannot be copied, copy-enabled state, and copy cycle, which saves display space and contributes to reducing the cost of the device. It is something to do.

1-s-7a-Display @48tJ container 41Dt-/(7 Stomach-Detects and displays the condition, and displays the container 53
Detects a lack of toner inside and displays a static display. In the case of the former, it is possible to blink the lamp and turn it on statically with a firefly.Also, in the case of paper display (641), it is also possible to blink the lamp and turn it on statically without using a cassette.

Also, the toner in the challenger 118 is insufficient or - the container is 10 over 7.
-- is detected, the number omw set using the numeric keypad 4g
When the copy is backed up, copying is continued until the set number of copies are completed, and subsequent copying is prevented. This is because it would cause a delay and reduce the actual copying speed. In addition, if the transfer paper becomes jammed, immediately stop the movement of the device #i to ensure safety. In addition, the stop key, press button, or power button signal completes the current process cycle without immediately interrupting the process and prevents the start of a subsequent cycle.

FIG. 4 is a block circuit diagram showing an example of the configuration of a control path of a copying machine according to the present invention. In the figure μOOM ij shoulder computer (for example, NEC voice control FD 5
45). This is the engineering IT ij interrupt port, and the pulse signal generated by the synchronous pulse generator ja40 is inputted after being waveform-shaped by a capacitor. 46-1 and 415-ja
#i 10th and 1st 6-year-old numerical display of sWJ fusegment display, Tri and Tra tj amplification transistors, ]) 6 is a driver, display Ig4! S-1,4
5-5l#i Dry/(capo segment far selected through Da) to UO-U6! ! followed by digit selection output book'-)P4. & value information is displayed in dynasec by the output of P5. 46 to 49 respectively correspond to the four indicators 46 to 49 in FIG. 3, and their lighting is controlled by the outputs 1O to 13. Copy key 40, stop d#--41.
In order to judge the states of the numeric keypad 42 and the keypad 43, repeated pulses are output from the output capo (KSO) 83. Each key is given its scan line and matrix S, and its key state is dynamically read into memory in pOOM by input KO~3. The number of copies made using the numeric keypad 42 is stored in μO (mouse M in JM, and the display 46-1 is displayed according to this information.
．． 45-2 displays numerical values. Human powered boat PO~P5jd
, read the 6 switches gl-860 type 1k of the second WA. Introducing Capo) To the ground through P Mu Welfare Connection 81! II
! be controlled. This becomes the basis for the judgment in step 1-2. 9 When the short-circuit line SIK uplink capom is grounded, control using the self-diagnosis program can be selected. Also, if it is not grounded, the self-diagnosis program cannot be selected. Note that the shorting line SB may be set at the time of shipment from the factory, or may be made operable by a service person. 23#i motor, 26 is connected to [1 clutch, 2etJ back latch, 1314, μO
The OM controls the operation of these drive units based on input signals.

The normal copying operation of the copying machine of this embodiment has been described above. Next, the self-diagnosis function of this copying machine will be explained. Diagnosis contents by the self-diagnosis function and when an abnormality is detected are displayed on the numerical display 45 in FIG. In the circuit shown in the 1m4 diagram, μ00MN
0 person capo) If Pmu is grounded by short circuit "Ume 8B", μOOM is activated by self-diagnosis program.
N becomes one power. That is, in step 2 of the 7w-chart of the control system shown in FIG. 1, control by the self-diagnosis program is enabled, so the process proceeds to step 4. And user relatives vhFi service! If the system requires self-diagnosis, press the numeric keypad 4 on the operation panel shown in Figure 3.
2 of 10” - 3 or more times in a row. As a result of this operation, the self-diagnosis program enters the specified state in step 4 of FIG.
The OM controls the drive of the device according to a self-diagnosis program.

Figure 6 is a 70-chart in detail 1 of the self-diagnosis program shown in step 5 of the 70-chart in FIG.

The self-diagnosis program shown in this 7-chart is μOO
M's l (OM K is pre-stored.

As mentioned above, the ``1υ'' key on the numeric keypad 4g on the operation panel is 5.
□According to the voice 00M ij self-diagnosis boogram when operated on a similar basis □ Drive control standby knee Kfisho, step 10
1, a blinking "0" is displayed on the display 45. This "0"
A flashing display indicates to the user that the device is
I know that there is something in it. The self-diagnosis lh is started by the operation of the copy key 40 of the operation section, and the operation of the copy key 40 is detected in step 102. copy +-4
0 is turned on, proceed to step 103. When the output of the paper detection switch S1 is at the p-level (hereinafter referred to as "p"), the output of the paper detection switch S1 is at the L1-eight level (-lower H).
) and 11 must be five.

Therefore, in step 103, the output of the paper detection switch s1 is OFF, and in step 104, the output of the manual feed detection switch 32 is L, and in step 103, the output of the paper detection switch 11 is L, and in step 105, the manual feed detection switch 32 is L. The detection switch 'f'a2 (If the DtB force is a wing, it is determined that the catfish paper detection switch 11 or the manual feed detection switch 8a is malfunctioning, and the display @461-1 in step xoaK4 is displayed blinking).

Then, in the normal state, the device #ll111 is stopped.

When the "1 point" blinking reward is activated, the operation section's Ta9A-43 is returned to ■ in Step 1Q'F.
At 01, the device enters the standby state for self-diagnosis again.

Below, if all 0III is displayed, step 101Kl is operated in the same manner as Taraaki-4s is operated while the display 19430 is blinking.
! Ru. If both the paper detection switch al and the manual feed detection switch s2 are normal, proceed to step 108 and switch the motor 23 to 2.
Turn on for seconds. At this time, the output of the separation switch S3 must be L because it should not detect the transfer paper. However, if the output of the separation switch 8s is K in step 109, it is determined that the separation switch 83 has failed, and step 110
Proceed to step 2, and display "2" blinking on the display 4s. Step 1
If the separation switch ssom force does not become H even after 2I6 elapses after the motor taS is turned on at steps 09 and 118, it is determined that the separation switch 83#i is correct, and the motor 83 is ORed at step 03. Next, in step 114, the output of the paper ejection switch 840 is determined, and since the paper ejection switch S4 will not be actuated by the transfer paper when it is K, the output must be L.

Therefore, in the company's case, it is determined that the paper ejection switch B4 is malfunctioning.
In step 115, the display 1145Kr3J is displayed blinking. If the output of the isolation switch 84 is L, it is considered normal.
Then, in step 11), the output of the fixed position switch SaO is detected. When the document table 1 is in the home position, the output from the fixed position switch 85 must be on. Therefore, in the case of H, it is determined that the output is not L even though the fixed position switch m6~ is operated by the document table l (the fixed position switch is open), and the display is displayed in step 11B. 1145Kr4J is displayed blinking. Also, if there is no failure in the fixed position switch, the output of the timing switch II6 is detected. At this time, the output of the power switch 86Fi must be dH since it is not operating as compared to the original IK. Therefore, in the case of L, it is determined that the timing switch 86 is not operated on the document table 1 and the output is L, which is a fault wiping operation (assuming a tying close fault), and step 1lii
1 to display 1143K I 5J blinking. Also, if the timing switch is not closed, step 1fli
: Turn on the clutch 23 with S, and at the same time turn on the forward clutch 25 for 1-2 seconds. While the switch 25 is on, two outputs from the fixed position switch 8b and the timing switch S6 are detected. While the output of the timing switch S6 maintains the foot, the output of the fixed position switch S5 #'iL
must change from H to H.

There are 2 cases in which this output change is extremely slow.

This is a case where the output of the timing switch 86 changes from H to H even though the output of the first K fixed position switch S5 does not change. That is, in step 124, the fixed position switch S5
The output of timing switch S6 is 11 steps 125
If the output becomes H, turn the fixed position switch S5.
It is determined that the error is # (fixed position switch closing failure), and the process proceeds to step 126, where "6" is displayed blinking on the display 45.

A second case is that both the output of the fixed position switch S5 and the output of the tie-back switch 860 do not change within 12 seconds after the forward clutch 250 is turned on. In this case, step 129
The program proceeds to * and turns off the advance clutch 85, and in step 130, reads the synchronizing pulses of the synchronizing pulse generator 24. If there is no synchronization pulse input in step 131, then
3 is determined to be a failure, and in step 134, the display 45 shows "7".
" will be displayed blinking. Further, if the input of the synchronizing pulse is confirmed, it is determined that the forward clutch 25 has failed, and step 132
++J is displayed blinking on the display 46.

However, after the forward clutch 25 is turned on, the fixed position switch 8
If the output loss of No. 6 occurs normally, it is determined that there is no problem with the fixed position switch closing and that the forward clutch 86 and motor 23 are also normal, and the process proceeds to step 137 after 12 seconds. In step 13, the forward clutch 25 is turned off, and at the same time, the reverse clutch 26 is turned on for 2 seconds. And step 13
8, a change in the output of the fixed position switch 85 is detected. At this point, it has already been determined that the fixed position switch 85Fi is normal, and if the output change does not occur within 2 seconds, it is determined that the advance clutch 26 is malfunctioning, and step 1
Displayed at 40 fi! 45 is displayed blinking. If the output of the fixed position switch 85 changes within two orders of magnitude, it is determined that the Fi reverse clutch 26 is normal, and the process proceeds to step 142. In step 142, the reverse clutch 26 is turned off, and in step 143
It is detected whether the flag l/"a 6 is set and ψ. In this case, since it is not set, step 1t
4 Turn on the lumberjack clutch 26 for 12 seconds. and,
At step 145, a change in the output of the timing switch S6 is detected. Then, within 12 seconds, the output is ■
If there is no change from IIK, timing switch s6
When the document table IK is activated, the K does not perform any switching operation, and the output is H, which determines that the state is lK (the tying switch is open), and in step 14, the display 1ii45 shows 11uJ. Display blinking. However, 12
If the output change occurs within seconds, it is determined that the timing switch 11&- is not present, and the process proceeds to step 149, where P/86 is set. And step 1
37, the forward clutch 26 is turned off and the reverse clutch 26 is turned on at the same time for 2 seconds. At this point, the reverse clutch 26ij is already normal, and at the same time as the localization 1 switch S5 goes to H in step 142, the reverse clutch 26 is turned off, and the process proceeds to step 143. Sudetsubu 143 and 7 lagushi/
Since b6 is set, the process advances to step 150 to continue the synchronization pulse. If no pulse is input in step 151, a synchronization pulse is generated! It is determined that the I24 is malfunctioning, and "ll" is displayed blinking on the display 46 in step 152. Also, if pulse input is confirmed, step 154
Km display 1145 K 1ooJ ta decrease display t le.

c.

A blinking display informs the user that all the self-diagnosis results were normal.

In this way, the drive of the device is controlled by the self-diagnosis program, and when a failure is detected, numerical information corresponding to the part and content of the failure is displayed blinking, and the device is stopped at that point. If the self-diagnosis determines that the cause is mψ, "Ioo" is displayed blinking to notify that there is no abnormality, and the device is stopped. When the numerical value is displayed as a dot and ψ is displayed, only the clear key 43 can be used manually, and by operating the clear key 43 in a series, the self-diagnosis standby state is returned. Further copy +-40
When activated, drive control is performed using a self-diagnosis program. Drive control solution using self-diagnosis program
&HA 1 by turning off the power to μOOM.

In addition, to detect an abnormality in a switch member that is activated by a document table, a transfer material, etc. and outputs a detection signal, a detection signal is output regardless of whether the switch member is operated, and an abnormal state of tkvh@x is detected. is being operated and ψ is not 1
It is possible to detect a second abnormal state in which a detection signal is output regardless of the condition.

As described above, according to the present invention, it is possible to detect a failure in each part of the image processing apparatus without performing an image forming operation on the apparatus. As a result, even if there is a faulty part in the apparatus, since the image forming operation is performed, there is no need for a detection operation, and further failures due to the faulty part are not caused.

Furthermore, by detecting failures in multiple parts one at a time in a predetermined order, and by not performing the next inspection operation unless it is determined that there is no failure, unreasonable detection operations are avoided. do not have. In addition, when a failure is detected, the part and contents of the failure are displayed so that the situation can be quickly explained to the KII.

In addition, if a print is detected, the details of the failure will be displayed.
If no failure is detected, the user can easily determine the status of the device by displaying the completion of the Ktlj self-diagnosis program.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing an outline of a control system to which the present invention is applied, FIG. 2 is a sectional view of a copying machine to which the present invention is applied, and FIG.
FIG. 4 is a block diagram of a control circuit according to the present invention, and 51 is a detailed 70-chart diagram of the 70-chart diagram in FIG. , 1lFi cassette, 23 #i motor, 24 is synchronous pulse generator, 25 is forward clutch %
2 a I: i Reverse clutch. Applicant Canon Co., Ltd. Copia Co., Ltd.

Claims (1)

[Scope of Claims] (31) An image forming apparatus using a miter computer for all sequence control is provided with a self-diagnosis system for detecting failures in each part of the apparatus. An image forming apparatus having a self-diagnosis function characterized by performing failure detection operations in a predetermined order and displaying the details of the failure when a failure is detected. (2. Claims Hm (1) An image forming apparatus having a self-diagnosis function ti, characterized in that the above-mentioned self-diagnosis preliminary selection is performed by numerical manual means for setting the number of repetitions of an image forming operation during normal image formation. (3) Patent In Clause (2) of Claim H, the switching means read directly from the input port of the microcomputer is used to determine whether or not the input port of the microcomputer is capable of or not being selected by the manual input means. (4) In claim HII (1), the above-mentioned image forming apparatus is provided on the display means for displaying the number of repetitions of the image forming operation during normal image forming. IN-type weapon W which has a self-diagnosis function characterized by displaying the details of the failure. An image forming apparatus having a self-diagnosis function, characterized in that the means for instructing the start of execution instructs the self-diagnosis progera to start a failure detection operation. (6) In claim part (1), normally An image forming apparatus having a self-diagnosis function that returns the image progera to a state of waiting for the start of execution. A self-diagnosis program is provided with a self-diagnosis program for detection, and when a failure is detected by the self-diagnosis program, the details of the failure are displayed, and when no failure is detected, the completion of the self-diagnosis program is displayed. (8) A moving member for image formation, a means for outputting a signal by being actuated by the moving member, and a change in the output signal of the signal outputting means when the moving member starts operating. 1. An image forming apparatus having a self-diagnosis function, characterized in that an abnormal state of the signal output means is determined by detection at the end of operation.