JPH03234695A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To accurately and simply grasp the state of an apparatus in the case of inspection and maintenance or repair by deciding the type of a detected malfunction, and historically storing a malfunction generating state regarding at least an operation of image forming means of the decided malfunctions. CONSTITUTION:The type of a malfunction generated as a history of malfunctions and a plant counting number when the malfunction occurs are stored in a malfunction history area 420b. As the malfunctions stored in the area 420b such as, for example, a sheet jam, no temperature rise of a heat roller 371, an improper image, a motor malfunction, etc., important factors are stored. The malfunctions not stored in the area 420b, include no sheet in cassettes 22, 30, 32, an open cover, no toner, etc. Malfunctions to be stored or not to be stored in the area 420b are decided by a CPU 401 at the time of a malfunction occurred, and only the history of the malfunction to be decided as the malfunction to be stored is selectively stored in the area 420b.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) This invention is applicable to, for example, a laser printer that receives image data from an external device and prints a recorded image on paper from the received data. The present invention relates to an image forming apparatus.

(Prior Art) Conventionally, image formation in an image forming apparatus such as a laser printer is performed through various steps such as charging, exposure, development, transfer, peeling, cleaning, and fixing. In such an image forming apparatus, a charging device, an exposure device, a developing device, a transfer device, a peeling device, a cleaning device, etc. are sequentially arranged around the photosensitive drum, and a fixing device is further provided to receive paper from the peeling device. By driving each of the above-mentioned devices according to the rotational movement of the photosensitive drum, each of the above-mentioned image forming steps is executed, and an image is formed on the paper.

For such laser printers, during maintenance inspections by service personnel or when a device abnormality occurs that cannot be recovered by the user, it is only possible to respond to the abnormality that is currently occurring, and there is no need to take any other measures. Abnormalities such as paper jams, which users can temporarily recover from, cannot be dealt with unless the user contacts us, and it is not possible to avoid device abnormalities that can be predicted to cause malfunctions in the future. In many cases, abnormalities were pointed out using ambiguous expressions, and there were problems such as it took time to understand the malfunction of the equipment itself, or it was understood incorrectly.

Therefore, there is a drawback that a service person cannot easily and accurately grasp the state of the device during maintenance inspection or repair.

(Invention or Problem to be Solved) As described above, the present invention eliminates the drawback that it is not possible to accurately and easily grasp the condition of the device during maintenance inspection or repair. An object of the present invention is to provide an image forming apparatus that allows the state of the apparatus to be accurately and easily grasped at the time of repair.

[Structure of the Invention] (Means for Solving the Problems) An image forming apparatus of the present invention includes an image forming means for forming an image on an image forming medium using image data from an external device. A detection means for detecting various kinds of abnormalities in the operation of the device, a discrimination means for discriminating the type of abnormality caused by the detection means, and an abnormality related to at least the operation of the image forming means among the abnormal conditions discriminated by the discrimination means. It is composed of a storage means for storing the occurrence status of a state as a history.

(Function) The present invention is equipped with an image forming means for forming an image on an image forming medium using image data from an external device. Among the determined abnormal conditions, the occurrence status of at least those abnormal conditions related to the operation of the image forming means is stored as a history.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIGS. 2 and 3 show the configuration of an image forming apparatus according to the present invention, for example, an image forming unit apparatus including a laser printer with optional equipment.

That is, the image forming unit device includes a multi-cassette feeder 2 that feeds paper (plain paper) P of a predetermined thickness such as cut paper as an image forming medium into a printer 1, and a multi-cassette feeder 2 that feeds paper (plain paper) P of a predetermined thickness such as cut paper as an image forming medium into the printer 1; Optional devices such as an envelope feeder 3 that feeds paper (cardboard) A that is thicker than paper into the printer 1, and a jogger 4 that distributes the paper P or paper A after image formation into predetermined number of sheets are equipped with a laser. It is configured by being connected to a printer 1. The multi-cassette feeder 2, envelope feeder 3, and jogger 4 are connected online to a control section (not shown) in the main body of the laser printer 1. An operation panel 100 is provided on the upper surface of the laser printer 1.

The laser printer 1 also includes a laser optical system (2, photoreceptor drum 17, charging device 18, developing device 19, transfer device 20, static eliminator 21, stripping device 35, fixing device 37,
In addition to process systems such as a cleaning device 45, a paper feed cassette 22, a delivery roller 23, and an aligning roller pair 25
, conveyor belt 36, gate 38, paper ejection roller pair 39.4
2 etc. are provided. The laser optical system 12 includes a semiconductor laser oscillator (not shown) that generates laser light;
A collimator lens (not shown) corrects the laser beam from this oscillator into parallel light, a polygon mirror (rotating Mirror > 13
, the f/θ lens 14, the mirrors 15 and 16, and a mirror motor 60 that rotates (drives) the polygon mirror 13.
It is composed of etc.

During the image forming operation, the laser beam from the laser optical system 12 corresponding to an image signal from an external device (not shown) or the operation panel 100 is transmitted to the photoreceptor drum 10.
imaged on the surface of The photosensitive drum 17 rotates in the direction of the arrow shown in the figure, and the surface thereof is first charged by the charging device 18, and then exposed by the laser optical system 12 in accordance with an image signal. That is, the laser beam generated from the semiconductor laser oscillator is scanned at a constant speed from the left to the right of the photosensitive drum 17 as the polygon mirror 13 is rotated by the mirror motor 60, thereby creating an electrostatic charge on the surface of the photosensitive drum 17. A latent image is formed. This electrostatic latent image is made visible by applying toner by a developing device (9).

On the other hand, the paper P serving as the image forming medium from the paper feed cassette 22 is taken out one by one by the delivery roller 23, and
4, and is guided to a pair of aligning rollers 25, and sent to a transfer section by this pair of rollers 25.

Also, to the transfer section, the paper P or the paper feed that is taken out one by one by the feed roller 32 from the paper feed cassette 30 in the multi-cassette feeder 2 and guided to the aligning roller pair 25 through the paper guide path 34.29. paper cassette 3
Paper P1 is taken out one by one by the delivery roller 33 from the envelope feeder 3 and guided to the aligning roller pair 25 through the paper guide path 34.29, or taken out one by one from the stacker 26 in the envelope feeder 3 by the exit roller 27. The aligning roller pair 2 passes through the paper guide path 28 and 29.
The paper A guided to the aligning roller pair 25 and the paper P fed from the manual paper feed section 44 and guided to the aligning roller pair 25 through the paper guide path 29 are fed into It will be sent accordingly.

Then, the paper P or paper A sent to the transfer section is brought into close contact with the surface of the photoreceptor drum 17 at the transfer device 20, and the toner image on the photoreceptor drum 17 is transferred by the action of the transfer device 20. . This transferred paper P or paper A is peeled off from the photosensitive drum 17 by the action of a peeling device 35, and is sent to a fixing device 37 by a conveyor belt 36, where it passes through a heat roller that generates heat for fixing. 37, the transferred image is thermally fixed. This heat roller 371 has a built-in heater lamp 37a for heating. After fixing, the paper P or paper A passes through a gate 38 and is delivered to the paper ejection tray 4 by a pair of paper ejection rollers 39.
o or by means of the gate 38 above the conveying path 4
1, and is sent to the paper ejection tray 43 by the paper ejection roller pair 42.
It is designed to be discharged upward.

Further, the photosensitive drum 17 after the transfer is cleaned by a cleaning device 4.
After the residual toner is removed in step 5, the residual image is erased by the static eliminator 21, thereby making it possible to perform the next image forming operation.

Note that the fixing device 37 is formed into a unit (user unit), and is configured to be able to be attached to and detached from the printer 1 independently. Further, in front of the pair of aligning rollers 25, there is an aligning switch 48 for detecting a paper feeding error to the transfer section by the pair of aligning rollers 25, etc., and in front of the pair of paper ejecting rollers 39, 42, an aligning switch 48 is provided. , are provided with paper ejection switches 49a and 149b for detecting paper ejection errors by the paper ejection roller pairs 39 and 42, respectively.

In addition, the paper feed cassette 22.30.3I has paper P
Paper detectors 50, 51, and 52 are arranged to detect the presence or absence of paper P in the paper feed cassette 22, 30, 3I, respectively.

Further, above the laser optical system 12, there is an engine control board equipped with an engine control circuit 70 that controls each electrical device provided in the apparatus main body 1 to control operations for completing the electrophotographic process. A board mounted with a printer control circuit 71 that controls the operation of the engine control circuit 70 is arranged.

Up to three boards for the printer control circuit 71 can be installed depending on the degree of function addition (for example, adding more types of fonts, kanji, etc.). Further functions can be added by inserting a function-adding IC card 517 into three IC card connectors 72 arranged on the front edge of the board 71. Furthermore, a connector (not shown) for connecting to a host device 409 (described later), which is an external output device such as a computer or word processor, is provided on the left end surface of the board of the printer control circuit 71 located at the bottom. has been done.

As shown in FIG. 4, the operation panel 100 has a number of panels,
Liquid crystal display 100 that displays the mode, guidance messages, etc.
a sAn LED display 100b that lights up and displays various statuses using LEDs, . . . , a next menu item key 100c that instructs various operations, and a previous menu item key 100d.

Value next item key 100e, value previous item key 10
01, and an online key 10 for switching between online and offline with the host device 409, which is an external output device.
It is composed of 0g. The above LED indicator 100b
,... is "online" indicating whether it is connected to an external device or not, that is, online/offline mode.
, "Ready" indicating that the device body 1 is ready for operation, "Data" indicating that the image is being transferred, "Operator" requesting an operator call, "Service" requesting a service call, and Auto/Manual. It is made up of indicators for each mode shown.

A plurality of menu information displayed on the left half of the liquid crystal display 100a is incremented each time the menu next item key 1000 is pressed, and the previous menu item key 1000 is incremented.
Each time 0d is pressed, each value is decremented and displayed, and these display operations are cyclically repeated. Also, a plurality of value information corresponding to the menu information displayed on the left half of the liquid crystal display 100a is incremented each time the value next item key 1000 is pressed, and decremented each time the value previous item key 100f is pressed. Each is displayed on the right half of the liquid crystal display 100a, and these display operations are cyclically repeated. The above menu information includes a history read mode, that is, a mode in which important abnormalities such as paper jams and the occurrence situation are displayed on the liquid crystal display 100a. In this mode, the history of the device, that is, the abnormality occurrence situation is displayed from the E2FROM 420 (described later). It is read out and displayed on the liquid crystal display 100a.

The operator presses the menu next item key 1000, the previous menu item key food, and the value next item key LOOe.
, and the value pre-item key LOOf to select and instruct the desired operation.

Next, the configuration of the engine control section will be explained.

FIG. 5 is a block diagram showing the configuration of main parts of the engine control section 300. In the figure, 302 is a power supply device;
By turning on the main switch 301, power supply voltages of +5V and +24V are output. The power supply voltage of +5V is supplied to the engine control circuit 70, and is further supplied to the printer control circuit 7 via this engine control circuit 70.
(Supplied to.

On the other hand, for +24V power supply voltage, use cover switch 303.30
4 is sequentially supplied to the engine control circuit 70. Then, the power is supplied to the scanner control circuit 101, the high voltage power supply 305, and the mechanism drive circuit 306 via the engine control circuit 70, respectively. A semiconductor laser 90 and a mirror motor 92 are connected to the scanner control circuit 101.
From the mechanism drive circuit 306, the pre-exposure device 21, main motor 307, manual paper feed solenoid 308, cassette paper feed solenoid 309, aligning solenoid 31
O, toner supply solenoid 311, and cooling fan 50
0, etc., and is used as a driving power source for these.

Further, the power supply device 302 is provided with a zero-cross switch type heater lamp drive circuit (not shown) consisting of, for example, a phototriac coupler and a triac, which drives the heater lamp 501 inside the fixing device 33. The above +24V is used as a driving power source for the light-emitting side LED of the coupler. In the heater lamp drive circuit with this configuration, as is well known, the light emitting side L
When the ED is turned on/off, the phototriac on the light emitting side is turned on/off at the zero cross point of the AC power supply, thereby turning on/off the triac, which is the main switch element in the next stage, and supplying the AC power S1 to the heater lamp 37a. It is designed to turn on or cut off electricity.

Then, a heater control signal S2 for turning on/off the light emitting side LED is sent from the engine control circuit 70 to the power supply device 302.
A temperature signal detected by a thermistor 37b provided in the fixing device 37 is supplied to the engine control circuit 70.

Further, the cover switch 303 is turned off when a cover (not shown) is rotated upward, and the cover switch 304 is turned off (not shown) when it is opened. Therefore, when the top cover or rear cover is opened, the switch 303.3
04 cuts off the +24V, the semiconductor laser 90, mirror motor 60, high voltage power supply 305, main motor 307, solenoids 308 to 311, cooling fan 500, heater lamp 37a, etc. stop operating, and the operator Even if the inside of the device main body 1 is touched, there will be no problem.

FIG. 6 is a block diagram showing the configuration of the engine control circuit 70. In the figure, the CPU 350 is the engine control unit 3
It controls the entire 00, and operates according to a control program stored in the ROM 351. RAM 352 is used as a working buffer for CPU 350. E2FROM3
53 stores the total number of prints and the like. The printer interface circuit 354 mediates the exchange of the interface signal S3 with the printer control circuit 71. The laser modulation control circuit 355 controls the semiconductor laser 90 to be forced to turn on periodically in order to generate a laser light detection signal S4, which will be described later, and also controls the laser light detection signal S4 sent from the printer control circuit 71 by the interface signal S3. It modulates and controls the semiconductor laser 90 according to image data,
A laser modulation signal S5 is output to the scanner control circuit 101.

The output register 356 receives control signals S6 and S7 that respectively control the mechanism drive circuit 306, the high voltage power supply 305, the scanner control circuit 101, and the heater lamp drive circuit.
, S8, and S2 are output. The voltage signals S9 and SIO generated by the thermistor 37b and the toner sensor 324 are input to the A/D converter 357, and these voltage values are converted into digital values. The manual register 358 includes the paper empty switch 320, manual feed switch 3211, and paper discharge switch 49a.

49b1 mounting switch 323, aligning switch 4
8, and status signals S11.8 from paper detectors 50.51.52. S12, S13, S14, S15 and the above +2
A 4V on/off status signal S1B is input.

Further, the internal bus 359 connects the CPU 350, ROM
351, RAM352, E2PROM353, printer interface circuit 354, laser modulation control circuit 355, output register 35B, A/D converter 35
7. Data is exchanged with the manual register 358.

The mechanism drive circuit 306 is provided with a drive circuit for driving various motors, solenoids, etc.
On/off is controlled by a binary control signal S6 output from the output register 356. That is, for example, each drive circuit is turned on when it is "1" and turned off when it is rOJ.
It is designed to energize or cut off electricity. The scanner control circuit 101 includes a semiconductor laser 90 and a mirror motor 6.
o drive circuits are provided. The semiconductor laser 9o is
On/off is controlled by the laser modulation signal S5 output from the laser modulation control circuit 355, and on/off of the mirror motor 60 is controlled by the control signal S8 output from the output register 35B. There is. Further, a PIN diode is used in the laser light detection sensor 312, and when the laser light a passes through the laser light detection sensor 312, a current proportional to the energy flows therethrough.

This current signal is sent to the laser modulation control circuit 355 as a laser light detection signal S4. Further, from the high voltage power supply 305, a developing bias power supply unit (not shown), a charging device 18, and a wire high voltage power supply unit (not shown) of the transfer device 20 are supplied with a developing bias S20,
High voltage signals for charging S22 and transfer S24 are output.

These on/off states are controlled by a control signal S7 of 1.0 output from the output register 356.

As described above, within the engine control section 300, power is supplied to each electric circuit via the engine control circuit 70, and each section is controlled by a binary control signal output from the engine control circuit 70. It has become. This engine control section 300 and a printer control section 400, which will be described later, are connected by an interface signal S3.

Next, the configuration of printer control section 400 will be explained.

FIG. 1 is a block diagram showing the configuration of the main parts of the printer control section 400. In the figure, a CPU 401 controls the printer control unit 400 as a whole.

The ROM 402 stores control programs.
The CPU 401 operates according to this program. Further, the ROM 402 stores data regarding the paper P such as a password to be verified when changing data, top machine, left margin, paper type, message information to notify the operator, and the like. The RAM 403 is used as a page buffer for temporarily storing image data sent from the host device 409. As shown in FIG. 7, the E2FROM 420 includes a print count area 420a for counting the total number of prints, an abnormality history area 420b, and an area 42 used for other purposes such as pitch.
It is composed of 0C. Abnormal history area 420b
The type of abnormality that has occurred and the print count number when the abnormality occurred are stored as a history of abnormal conditions.

The abnormalities stored in the abnormality history area 420b are important ones such as a paper jam, the temperature of the heat roller 371 not rising, the occurrence of a defective image, and a motor abnormality. As for paper jams, the position where the jam occurred is also stored. Abnormalities that are not stored in the abnormality history area 420b include no paper in the paper feed cassette 22, 30, and 31, an open cover, and no toner. Whether an abnormality is stored in the abnormality history area 420b or not is determined by the CPU 40 when the abnormality occurs.
1, and only the history of abnormal conditions for those determined to be abnormal to be stored is selectively stored in the abnormality history area 420b.

The extended memory 404 has a large capacity and is used when the image data sent from the host device 409 is a large amount of data such as bitmap data and the RAM 403 cannot store one page of data. It's memory. Video RAM 405 stores image data expanded into bit images, and its output is supplied to serial-parallel conversion circuit 406. The serial-parallel conversion circuit 406 converts the image data developed into a bit image in the video RAM 405 and sent as parallel data into serial data, and sends the serial data to the engine control circuit 70.

The host interface 408 exchanges data between the printer control unit 400 and a host device 409, which is composed of, for example, a computer or an image reading device, and has two types: a serial transfer line 410a and a parallel transfer line 410b. We are prepared. Then, it can be used appropriately depending on the type of data transferred to and from the host device 409. The engine interface 4H mediates the exchange of an interface signal S3 between the printer control circuit 71 and the engine control circuit 70. The connection circuit 413 cuts off the power supply and signal line supplied to the IC card 5i7 when the IC card 517 is inserted into or removed from the connector (not shown). IC card 5 due to the noise generated.
This is to prevent the data stored in 17 from being destroyed.

The operation panel control circuit 407 controls displaying a guidance message on the liquid crystal display 100a of the operation panel 100;
Control of lighting, turning off, and blinking of LED display 1oob, menu next item key 100c, previous menu item key 100d
, value next item key 100e, value previous item key 1
00f and the online key 100g to control sending data manually to the CPU 401. Further, the internal bus 412 is connected to the CPU 401, R
OM402, RAM403, expansion memory 404, video RAM405, operation panel control circuit 407, host interface 408, engine interface 411
, the connection circuit 413, and the E2PROM 420.

Further, the IC card 517 is a non-volatile memory, for example, a static RAM with battery backup, an E2P
It is composed of a ROM SEPROM, a mask ROM, or the like. These IC cards 517 store, for example, character fonts, emulation programs, and the like.

Next, the configuration of the interface signal S3 will be explained.

FIG. 8 shows each signal of the interface signal S3. In the figure, DO-D7 is an engine control circuit 70
This is a bidirectional data bus that transmits status from the printer control circuit 71 to the printer control circuit 71 and commands from the printer control circuit 71 to the engine control circuit 70, and the status and commands are switched and used at the timing shown in FIG. It looks like this. That is, the engine control circuit 70
When the bus direction signal DIR is set to a low level when the busy signal BSYO output from the DO-D7 is at a high level (not busy), the DO-D7 is switched in the direction of transmitting a signal from the engine control circuit 70 to the printer control circuit 71. The status is output on DO-D7. This allows the printer control circuit 71 to read the status.

On the other hand, when the printer control circuit 71 sends a command, when the bus direction signal DIR is set to a high level when the busy signal BSYO is at a high level (not busy), the DO-D7 sends a signal from the printer control circuit 71 to the engine control circuit 70. The direction is switched to transmit the command, and the command is output on the DO-D7. When the strobe signal 5TBO is set to a low level in this state, the engine control circuit 70 reads the command on DO-D7 while the strobe signal 5TBO is at a low level, and the busy signal BSYO is set to a low level (busy state). . In this busy state, the engine control circuit 70 performs processing such as command analysis. When the busy signal BSYO is set to a low level, the printer control circuit 71 returns the strobe signal 5TBO to a high level and ends the command transmission. Then, when the command processing in the engine control circuit 70 is completed, the busy signal B
SYO is returned to high level again.

Note that commands sent while the busy signal BSYO is at a low level are not received by the engine control circuit 70. Furthermore, the status on the data bus Do-D7 does not change immediately when a state change occurs in the engine control unit 300, but is updated only when the status is returned in response to a command received after the state change. There is.

The attention signal ATN1 is output when the basic status on the print sequence between the engine control circuit 70 and the printer control circuit 71 changes, and the attention signal ATN1 is output when the basic status on the print sequence between the engine control circuit 70 and the printer control circuit 71 changes.
It is set to a high level when it becomes possible to receive a SYNC command and when one page of image data has been received.
It is reset to a low level when an attention reset command is received. Therefore, when the attention signal ATN1 changes from a low level to a high level, the printer control circuit 71 operates on the data bus DO-D7.
sends an attention reset command to the data bus DO, resets the attention signal ATN1, and then sends an attention reset command to the data bus DO.
-You can read the status on D7 and know the changed basic status. In addition, the above basic status is also output on the data bus by the basic status request command that requests the basic status, so the content of the changed basic status can be known by the basic status request command prior to the above attention reset command. is now possible.

The ready signal PRDYO indicates that the engine control unit 300 is in a ready state when it is at a low level, and indicates that the engine control unit 300 is in a ready state when it is at a high level. When this signal is at a low level, a print operation by the engine control unit 300 is possible. It is.

System clear signal 5CLRI is printer control circuit 71
200~ after +5V rises with the reset signal of
The level remains high for 500 m5ec, during which the printer control circuit 71 enters the reset state.

The prime signal PRIMEO is a reset signal to the engine control circuit 70. While this signal is at a low level, the busy signal SYO is at a low level, the ready signal PRDYO is at a high level, and the engine control circuit 70 is set to a predetermined initial state. return.

The horizontal synchronization signal H3YNCO is a signal T, VSY, generated every time the laser exposure unit 22 scans one line.
The number of lines corresponding to the effective print length in the transport direction of the paper P after receiving the NC command is output in synchronization with the laser light detection signal S4.

The video clock VCLKO is the horizontal synchronization signal H8Y.
This is a synchronization clock for inputting one line of video data (image data) VDO to the engine control circuit 70 following Nco, and is output in a number corresponding to the effective print width of paper P in the horizontal scanning direction. Then, the video data VDO is taken into the engine control circuit 70 in synchronization with the falling edge of the video clock VCLKO.

In accordance with the video data VDO, the laser exposure unit 22 performs exposure scanning on the photoreceptor drum 17 to form a latent image on the photoreceptor drum 17. In addition,
When the video data VDO is at a low level, it is visualized on the paper P as a dot image.

Next, in the above configuration, the operation of the printer control circuit 400 according to the data transfer procedure will be explained in the 10th section.
This will be explained with reference to the flowcharts in FIGS. (a) and (b).

For example, now a laser printer is offline and C
When the PU 401 determines that it is in the offline state (step 5T1), the host device 40
It is checked whether the printing process for the received data from 9 has been completed (step 5T2). If it has not been completed, the process branches to step 5T12 to continue the printing process.

On the other hand, if the printing process is completed, the above step STI
, Sr1 are repeatedly executed to create an idling state and wait for the laser printer to be placed on-line.

When the laser printer is brought online in this state, it is checked whether the data sent from the host device 409 is a command (step 5T3), and if it is a command, it performs the operation corresponding to the command. (Step 5T4) If it is not a command, the execution of the above command is skipped and the process proceeds to step ST5. The above commands, for example, define the attributes of the following data or control the printer without sending or receiving data. Next, it is checked whether the page buffer provided in the RAM 403 as a buffer for data reception is full (step 5T5), and if it is not full, the data sent from the host device 409 is used as an image. It is checked whether it is data (step 5T6). If it is not image data, the process returns to step STI and waits for command or image data to be received by repeating the above series of steps. In such a state,
When it is determined in step ST6 that image data has been received, the received image data is sequentially stored in the page buffer (step 5T7).

Also, it is checked whether a print request has been issued (step 5T30). If it is determined that no print request has been issued, it is determined that the print preparation on the engine side has not been completed, and step S
Return to the TI and re-execute the above series of steps to wait for a print request to be issued. On the other hand, if it is determined that a print request has been issued, it is determined that the engine control unit 300 is ready for printing, and a print command is sent (step 5T31).
).

Next, it is checked whether the storage for one page has been completed (step 5T8), and if the storage has not been completed, the operation panel 1
The "data 1 lamp" of the LED display 100b provided in the LED display 100b starts blinking (step 5TIO).Next, by returning to step ST1 and executing the above series of steps, one page is stored in the page buffer. Wait until the image data for 100 seconds has been accumulated.When it is determined that the image data for one page has been stored by repeatedly executing the above series of steps, the above-mentioned ``Turn off the data 0 lamp'' step 5T9). End data reception processing. Then, the process moves to the print processing after step 5T12. Note that if it is determined in step ST5 that the page buffer is full, the data reception operation is stopped (step 5T11), and in this case as well, the process moves to the printing process from step 5T12. In this way, during the data reception operation, the "data" lamp is blinked to notify the operator.

Next, when the storage of one page's worth of image data in the page buffer is completed, it is checked whether the scan buffer provided on the video RAM 405 is full (step 5T12). Here, if it is determined that the scan buffer is not full, the CPU 401 converts the image data equivalent to 64 lines of image data stored in the page buffer into bit image data of a character image, and uses the image data as the scan buffer. Video RAM4
05 (step 5713). On the other hand, if the scan buffer is full, step 5T13 is skipped.

Next, it is checked whether the VSYNC command has been sent (step 5T20). When it is determined that the VSYNC command has not been exited, it is checked whether a VSYNC request has been issued from the engine side (step 5T21). Then, if it is determined that no VSYNC request has been issued, step S
Return to TI, perform the above series of steps again, and then
Wait for a SYNC request to be issued. When it is determined in step 5T21 that a VSYNC request has been issued, a VSYNC command is sent to the engine (step 5T22), and the process returns to step ST1 to output the horizontal synchronization signal H8YNCO and video clock VCLKO.
Shifts to a state where it waits for input.

In this state, in step 5T20 above, VSY
When it is determined that the NC command has already been exited, it is checked whether the transfer of one page of image data has been completed (step 5T26), and if the transfer of image data has not been completed, 6 stored in the scan buffer
The image data of the bit image for four lines is sent to the engine side in synchronization with the horizontal synchronizing signal HSYNCO and the video clock VCLKO (step 5T25). on the other hand,
The CPU 401 returns to step 5T13 and waits for the transfer of one page of image data to be completed while executing the above series of steps again. When the transmission of image data for one page is completed in this way, the E2PROM4
The total number of prints in the print count area 420a of 20 is counted up (step 5T27), and then the process returns to step STI, where the printer control circuit 71 returns to its initial state and becomes ready to transfer the image data of the next page.

Next, the operation of the engine control section 300 of the laser printer will be explained with reference to the flowcharts shown in FIGS. 11(a) to 11(e).

First, when the main switch 301 is turned on, a reset signal (not shown) is generated in synchronization with the rise of the +5V power supply.
occurs, and the engine control circuit 70 enters a reset state. Further, this reset signal outputs a reset signal 5CLR1 (see FIG. 8) to the printer control circuit 71, and the printer control circuit 71 is also reset.

Then, after the +5V power supply is turned on, 200 to 500
After m5ec, the value of the reset signal is inverted, the reset state is released, and the CPU 350 starts executing the program stored in the ROM 351.

That is, first, data such as the RAM 352 is initialized (step 5T50). Next, input register 3
The state of each switch is read in step 58, and it is checked whether an operator call state such as paper jam, cover open, process unit not installed, or paper empty has occurred (step 5T51). Here, if an operator call has occurred, it is checked whether only paper empty has occurred (step 5T52), and if an operator call other than paper empty has occurred, the process returns to step 5T51 and the operator Wait until the call state is released. On the other hand, when only paper empty occurs in step 5T52, or when no operator call occurs in step 5T51, heating of the fixing device 37 is started (step 5T53). Next, to initialize the electrophotographic process, the main motor 307 and pre-exposure device 21 are turned on (step 5T54), and then charging S22 is turned on sequentially at time intervals determined by the program (step 5T54). 5T55), and the developing bias S20 is turned on (step 5T56).

In this state, it is checked whether a certain period of time (approximately 30 seconds) has elapsed (step 5T57), and until the certain period of time has elapsed, it is checked whether or not the cover has opened (step 5T90). Then, when a cover open occurs, step 5T53 to 5T described above.
Turn off each output turned on in step S T 9
1. ), the process returns to step 5T51 again. On the other hand, when it is confirmed in step 5T57 that a certain period of time has elapsed, the charging S
22 is turned off (step 5T58), then the developing bias S20 is turned off (step 5T59), and the main motor 307 and pre-exposure device 21 are turned off (step 5T60). Through the series of operations from step 5T53 to step S60, the warming-up operation of the image forming apparatus is completed.

Then, the ready signal PRDYO is output (changed from high level to low level), a print request is set on the data bus DO-D7, and the attention signal ATN1 is output (changed from low level to high level).
and becomes ready for printing (step 5T61). Note that the fixing device 37, which has started heating in step 5T53, reaches a temperature sufficient for the fixing operation in the process leading to step 5T61.

Further, when an operator call occurs, its contents are outputted onto the data bus as operator call status.

On the other hand, in the state of step 5T61, the printer control circuit 7
1 can recognize the print request by sending the above-mentioned attention reset command to reset the attention signal ATN1 to a low level, and then reading the status on the data bus according to the above procedure. In FIGS. 11(a) to 11(e), the attention reset command, the process of resetting the attention signal ATN1 (changing from high level to low level), and the printing operation for the second sheet are omitted.

Next, it is checked whether a print command has been received (step 5T62). If a print command is not received, it is checked whether an operator call has occurred (step 5T92), and if an operator call has occurred, the print request is canceled and the operator call status is set. The ready signal PRDYO is set to high level (step 5T94). Then, it is checked whether or not a cover open has occurred among the factors of the operator call (step 5T95), and if a cover open has occurred, the process returns to step ST51. On the other hand, if the cover oven is not occurring, the process returns to step 5T92 and waits for the operator call to be released. In step 5T92,
When no operator call occurs, ready signal P
It is checked whether RDYO is at a low level (step 5T93), and when this signal is at a low level, the process returns to step 5T62 to wait for a print command, and when it is at a high level, the not ready state has already been reached at step 5T94. Therefore, the process returns to step 5T61 and the ready state is restored again. That is, the above steps 5T62→5T92→
The flow from 5T93 to 5T62 is a state of waiting for a print command, a so-called standby state.

When it is determined in step 5T62 that a print command has been received, the print request is reset and a series of print operations are performed. That is, first, the mirror motor 60 is turned on (step 5T63).
, then sequentially at predetermined time intervals, the main motor 3
07 and the pre-exposure device 21 are turned on (step 5T64
), charging S22, and cassette paper feed solenoid 309 are turned on, and the basic status is set to paper conveying (step 5T65). Furthermore, the developing bias S20 is turned on (step 5T66), and the cassette paper feed solenoid 309 is turned off (step 5T6).
7).

Here, while the cassette paper feed solenoid 309 is on, the feed roller 23 rotates once, and the paper P is taken out from the paper feed cassette 22 and conveyed toward the aligning roller pair 25. . Then, after a certain period of time has elapsed since the paper P was fed, it is checked whether or not the aligning switch 48 is on (step 5T68). When the aligning switch 48 is not turned on, it is determined that the paper P has not reached the aligning roller pair 25, and the paper is handled as a paper jam.

That is, the operator call status (jam) is set and the ready signal PRDYO is set to 1 (step 5T96).Furthermore, each device turned on in the process from step 5T63 to step 5T66 is turned on at the timing determined by the program. They are sequentially turned off (when the aligning switch 48 is on in step ST, the VSYNC request is set and the attention signal ATN1 is output (changed from low level to high level) (step S76). and,
It is checked whether a VSYNC command has been received (step 5T70), and when the VSYNC command is received, the VSYNC request is reset, data transfer in progress is set, and laser exposure is started.

That is, the reception of the video data VDO is started while transmitting the horizontal synchronization signal H5YNCO and the video clock VCLKO, and the video data VDO is recorded on the photoreceptor drum 17.
The image pattern of D○ is exposed (step 5T7
1). Note that until step 5T71, the pair of aligning rollers 25 remains stopped, so the sheet P stops when its leading edge reaches the pair of aligning rollers 25. After a certain period of time has elapsed, the aligning solenoid 310 is turned on (step 5T72), and as a result, the aligning roller pair 25 begins to rotate and the paper P is conveyed toward the transfer device 20. Note that the aligning solenoid 310 is turned on at a timing such that the leading edge of the image on the photosensitive drum 17, whose exposure was started in step 5T71, and the leading edge of the paper P coincide. Then, the transfer S24 is turned on at the timing when the leading edge of the paper P reaches the transfer device 20 (step 5T73). The toner image formed on the photoreceptor drum 17 by the developing device 19 is transferred to the sheet P transported in this manner by the transfer device 20 . Furthermore, when the trailing edge of the paper P has completely passed through the paper feed cassette 22 and the next paper P can be fed, a print request for the second paper P is set and the attention signal ATN 1 is activated. It is output (changed from low level to high level) (step 5T74). on the other hand,
After a certain period of time has elapsed since the paper P was conveyed from the pair of aligning rollers 25, the paper ejection switch 49a1 or 4
It is checked whether 9b is on (step 5).
T75), if it is not on, it is determined that the leading edge of the paper P has not reached the paper ejection roller unit 42, the print request is reset, the operator call status (jam) is set, and the ready signal P is turned on.
RDYO is set to 1 (step ST98). Then, each device that has been turned on up to step 5T74 is turned off in sequence (step 5T99), and the process returns to step 5T92. On the other hand, if the paper ejection switch 49a1 or 49b is on, the process waits until one page of image data, which was started to be received in step 5T71, is captured (step 5T76). When the reception of the image data is completed, the data transfer status is reset and the attention signal ATN1 is output (changed from low level to high level) (step 5T77). Next, the aligning solenoid 310 is turned off at the timing when the trailing edge of the paper P passes the aligning roller pair 25 (step 5T7).
8), the aligning roller pair 25 stops. moreover,
At the timing when the trailing edge of the paper P passes the transfer device 20,
Transfer S24 is turned off (step 5T79).

Next, after a certain period of time has elapsed since the aligning solenoid 310 was turned off, the paper ejection switch 49a1 or 49a1
9b is off (step 5T80). If it is not turned off, it is determined that the trailing edge of the paper P has not passed the paper discharge roller unit 42, and the process branches to step 5T98, where jam processing is performed. On the other hand, when the switch is off, it is determined that the paper P is being ejected normally, the paper transporting status is reset, the band '1Es22 is sequentially turned off (step 5T82), and the developing bias S20 is turned off. The printer is turned off (step 5783), the mirror motor 60 is turned off (step 5T84), and the pre-exposure device 21 and main motor 307 are turned off (step 5T85), completing a series of printing operations and returning to step 5T62 again to standby. become a state.

Further, processing to be performed when an abnormality occurs during the above-mentioned processing will be explained with reference to the flowchart shown in FIG. 12. That is, when various abnormalities occur, that is, when an abnormality detection signal is supplied from the engine control circuit 70 to the CPU 401 via the engine interface 411, the CPU 401 notifies the abnormal state on the liquid crystal display section 100a of the operation panel 100. Next, the CPU
401 determines whether or not the error is an error that requires a history, and if a history is required, it is recorded in the error history area 420b in the E2FROM 420, and if a history is required, the error history in the E2PROM 420 is recorded. Area 4
Recording processing to 20b is not performed. When performing recording processing to the abnormality history area 420b in the E2PROM 420, C
The PU 401 checks whether the error history area 420b is full, and if it is not full, stores the type of the current error and the print count at the time the error occurred in the free area, and if it is full, stores the oldest The history is deleted, the type of current abnormality and the print count at the time the abnormality occurred are stored in that area, and the history is saved with priority given to the latest information.

For example, when an important abnormality occurs such as a paper jam, the temperature of the heat roller 371 not rising, the occurrence of a defective image, or a motor abnormality, the type of abnormality and the print count at the time of the abnormality are memorized. Paper cassette 22.30
．． When an important abnormality such as 81 out of paper, cover oven, or out of toner occurs, its history is not stored.

Next, the history read mode in the above configuration will be explained with reference to the flowchart shown in FIG. 13. In this case, the history can be read in the maintenance mode, which is only available to service personnel, and when the read mode is entered, the newest abnormality history is displayed.

For example, in maintenance mode, a host device 409 with a display such as a laptop computer connects the serial transfer line 41 to the host interface 408.
If connected with 0a, CPU 401 is E2PRO
The history of all abnormal occurrences stored in the abnormality history area 420b of the M420 is transmitted from the host interface 408 to the host device 40 via the serial transfer line 410a.
9, and a list of all abnormal history is displayed on the display unit of the host device 409.

Furthermore, if the host device 409 is not connected,
CPU401 is E2PROM420 abnormality history area 4
The history of abnormality occurrences stored at the beginning of 20b is read out and displayed on the liquid crystal display section 100a as shown in FIG. Then, when the value previous item key 100f is pressed, the reading position moves to the old history, and the CPU 401
reads out the history of abnormality occurrences stored next to the abnormality history area 420b of the E2PROM 420, and displays it on the liquid crystal display section 1.
Displayed as 00a. Also, value next item key 1000
When is pressed, the read position moves to a new history, and C
The P U 401 reads out the history of the latest occurrence of an abnormality from the abnormality history area 420b of the E2PROM 420 and displays it on the liquid crystal display section LOOa. When the previous value item key 1oor is further pressed while the oldest history information is being read, the CPU 401 reads the information as shown in FIG.
A guide as to whether or not to delete the history is displayed on the liquid crystal display section 100a. In accordance with this guidance, when the value previous item key toor is further pressed, CPU4011; LE2PR
All stored information, that is, history, in the abnormality history area 420b of the OM 420 is erased.

As mentioned above, the history of abnormality occurrences is selectively stored in the E2FROM for important ones, and the record is kept even when the power is turned off. The type of abnormal state is stored, and the stored history of abnormal conditions can be read out and displayed on the liquid crystal display by instructions from the operation panel, and the history that is no longer needed can be deleted.

Thereby, the state of the device can be accurately and easily grasped during maintenance inspection or repair. Furthermore, when there is a limit to the number of history records stored, only important history records can be kept, making it effective.

In addition, by knowing the history of abnormal conditions, maintenance and repair work can be reliably and abundantly obtained, which not only improves work efficiency, but also helps prevent product problems by collecting and aggregating history information from all devices. You can clearly understand points, trends, characteristics, etc.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide an image forming apparatus in which the state of the apparatus can be accurately and easily grasped at the time of maintenance inspection or repair.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention. Fig. 1 is a block diagram showing the configuration of the main parts of the printer control section, Fig. 2 is an external perspective view of the laser printer, and Fig. 3 shows the internal structure of the laser printer. 4 is a plan view showing the structure of the operation panel, FIG. 5 is a block diagram showing the structure of the main parts of the engine control section, FIG. 6 is a block diagram showing the structure of the engine control circuit, and FIG. The figure shows an example of E2FROM storage, FIG. 8 shows each signal making up the interface signal, and FIG.
The figure is a timing chart for explaining data bus switching timing, Figure 10 is a flowchart showing the operation of the printer control circuit, Figure 11 is a flowchart showing the operation of the engine control section, and Figure 12 is the process when an abnormality occurs. FIG. 13 is a flowchart for explaining the history reading mode, and FIGS. 14 and 15 are diagrams showing examples of display on the liquid crystal display section when reading the history. 17... Photosensitive drum, 21... Charging device, 12...
...Laser exposure unit, 19...Developing device, 20.
... Fixing device, 22 ... Paper feed cassette, 23 ... Delivery roller, 25 ... Aligning roller pair, 48 ...
- Aligning switch, 70... Engine control circuit, 71... Printer control circuit, 100... Operation panel, 100a... Liquid crystal display section, 100b... LED
Display, 1one...Menu next item key, 1oad
... Menu previous item key 100e... Value next item key 100f... Value previous item key, 100g
...Online key, 300...Engine control section, 3
0B... Mechanism drive circuit, 400... Printer control unit, 401... CPU, 402... ROM, 403
...RAM, 405...Video RAM. 405a... Day live font area, 405b
゛°°Bit image development area, 409... host device, 420... E2PROM (storage means), 42
0b: Abnormal history area, P: Paper (image forming medium).

Claims (1)

[Scope of Claims] An image forming apparatus equipped with an image forming means for forming an image on an image forming medium using image data from an external device, a detecting means for detecting various abnormalities in the operation of the apparatus; a discriminating means for discriminating the type of abnormality caused by the detecting means; a storage means for storing a history of the occurrence of abnormal states at least related to the operation of the image forming means among the abnormal states determined by the discriminating means; An image forming apparatus comprising: