JPH1026913A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of surely performing a paperless print test at high speed. SOLUTION: A thermistor 12 for monitoring the temperature of a fixing device, a switch 13 for monitoring whether or not paper exists, and a switch 14 for monitoring whether or not a toner cartridge is loaded are connected to the CPU 11 of a printer engine 111. A controller 101 detects the temperature rise of the fixing device and the loaded state of the paper and the toner cartridge through the thermistor 12 and the switches 13 and 14. When such a state is not adapted to recording in ordinary recording operation, a ready signal 15 is not outputted to the controller 101. In the case a test signal 116 is inputted from the controller 101 in order to surely execute the paperless print test at high speed, the ready signal 15 is unconditionally outputted to the controller 101 regardless of the detected state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a controller that converts input image data into bitmap image data and supplies the bitmap image data to a printer engine, and a printer engine that performs recording control based on the image data input from the controller. And an image forming apparatus having the same.

[0002]

2. Description of the Related Art As an image forming apparatus for converting image information from a host computer or the like into a bitmap and recording it,
Various recording methods such as an electrophotographic method and an ink jet method are used.

[0003] In particular, an electrophotographic image forming apparatus converts image information from a host computer or the like into bitmap video data and supplies it to a printer engine (hereinafter simply referred to as an engine), and records the video data based on the video data. There is an engine that performs control, and in the production thereof, these controllers and the respective manufacturers of the engine may be different.

FIG. 5 shows the configuration of a general color image forming apparatus.
Shown in

[0005] In FIG.
02 to 105 are Y (yellow), M (magenta), C
A page memory for each color (cyan) and Bk (black). Known color data conversion means (masking, UCR) based on RGB data from a host computer or the like.
The data of Y, M, C, and Bk generated by 106 are stored. That is, the video data sent from the host computer 109 is stored in the page memory for each color data in an address corresponding to all pixels. The CPU 107 is connected to the host computer 109 via an interface 108, and controls the inside of the controller 101 upon receiving a signal from the host computer 109. A video interface 110 receives a print signal from the CPU 107 and sends video data, control commands, and the like to the engine 111.

First, during normal printing, the CPU
107, for example, sequentially from the page memory of each color, for example, Y, M,
Each color data is read out in the order of C and Bk,
To the control command. The engine 111 obtains a permanent image through an exposure-development-transfer-fixing process based on the video data of each color.

Further, in order for a serviceman to perform a test print or to know the internal state of the engine, the controller 101 sends a command to the engine 111 via the video interface 110 based on an instruction from the operation panel 112. Status to controller 1
01, and the controller 101 displays the result on the operation unit 112 based on the return status.

Here, the configuration of the engine of the color printer will be briefly described with reference to FIG.

In the configuration shown in FIG. 6, a color image developed by an image forming unit having a fixed black developing unit and three rotatable color developing units and multiply transferred to an intermediate transfer body is supplied from a feeding unit. The color image is formed by further transferring the image onto the transferred transfer material 202. The transfer material 202 is the fixing device 2
25, the color image is fixed on the transfer material 202,
The sheet is discharged to a discharge section 237 on the upper surface of the apparatus by a discharge roller. Note that the rotatable color developing device and the fixed black developing device are configured to be individually detachable from the printer main body.

The configuration shown in FIG. 6 corresponds to a hardware portion of the printer engine.

Exposure to the image forming section is performed by the scanner 230.
Sent from That is, when video data is given to the laser diode, the laser diode irradiates the polygon mirror 231 with image light modulated by the video data.
The polygon mirror 231 is driven to rotate at high speed by a scanner motor, and the image light reflected by the polygon mirror 231 selectively exposes the surface of the image carrier 215 rotating at a constant speed via the imaging lens 232 and the reflection mirror 233. It is configured as follows.

Next, the structure of each section of the image forming section will be sequentially described in detail.

[Image Carrier Unit] Drum Unit 21
Reference numeral 3 denotes an image carrier (photosensitive drum) 215 and a container 214 of the cleaning device which also serves as a holder for the image carrier 215. The drum unit 213 is detachably supported by the printer main body. The unit can be easily replaced according to the life of the device.

The image carrier 215 is formed by coating an organic photoconductor layer on the outside of an aluminum cylinder, and is rotatably supported by a container 214 of a cleaning device also serving as a holder for the image carrier 215. A cleaner blade 216 and a primary charging means 217 are arranged on the periphery of the image carrier 215, and the image forming operation of the image carrier 215 is performed by transmitting a driving force of a drive motor (not shown) to one end on the rear side in the figure. Is rotated in the counterclockwise direction in the figure according to.

[Charging Means] The charging means 217 uses a contact charging method.
The surface of the image carrier 215 is uniformly charged by applying a voltage to the conductive roller.

[Cleaning Unit] The cleaning unit transfers the toner visualized on the image carrier 215 by the developing unit to the intermediate transfer member 209, and then transfers the toner to the image carrier 215.
This is for cleaning the remaining toner, and the cleaned waste toner is stored in the cleaner container 214. The amount of waste toner stored in the container 214 does not fill the container 214 earlier than the life of the image carrier. Therefore, the cleaner container 214 is simultaneously replaced when the life of the image carrier 215 is replaced.

[Developing Means] The developing means is provided to convert the latent image into a visible image by forming Y (yellow), M (magenta),
It is composed of three rotary developing units 220Y, 220M, 220C and one black developing unit 221B that can develop each color of (cyan) and Bk (black).

The black developing device 221B is a fixed developing device. A sleeve 221BS is disposed at a position facing the image carrier 215 at a small distance from the image carrier 215, and a visible image of black toner is formed on the image carrier 215. Form.

The black developing unit 221B feeds the toner in the container by a feed mechanism, applies a thin layer of toner to the outer periphery of the sleeve 221BS rotating clockwise in the drawing by an application blade 221BB pressed against the outer periphery of the sleeve 221BS, and Charge (frictional electrification). Further, by applying a developing bias to the sleeve 221BS, toner development is performed on the image carrier 215 in accordance with the latent image.

Three rotary developing units 220Y, 220M, 2
Reference numeral 20 </ b> C is detachably held by a developing rotary 223 that rotates about a shaft 222, and the shaft 2 is held in a state where each developing device is held by the developing rotary 223 during image formation.
22 is rotated and a predetermined developing device is moved to the image carrier 2.
15, the developing sleeve is positioned so as to face the image carrier 215 at a small interval, and then a visible image is formed on the image carrier 215. At the time of forming a color image, the developing rotary 223 rotates for each rotation of the intermediate transfer member 209, and the developing process is performed in the order of the yellow developing device 220Y, the magenta developing device 220M, the cyan developing device 220C, and then the black developing device 221B. Rotates four times to sequentially form a visible image by each of the Y, M, C, and Bk toners. As a result, a full-color visible image is formed on the intermediate transfer member.

Each of the rotary developing devices 220Y, 220M, 2M
When each developing device is rotated to the developing position, each sleeve of 20C is connected to a high-voltage power supply for each color development and a drive provided in the printer main body, and a voltage is selectively applied to each color development sequentially and the drive is connected. It has become so.

[Intermediate Transfer Body] The intermediate transfer body 209 rotates clockwise in the figure to receive four multiple transfers from the image carrier during a color image forming operation. The transfer material 202 is sandwiched and conveyed by the transfer roller 210 to which the voltage is applied, so that the toner images of the respective colors on the intermediate transfer body are simultaneously and multiple-transferred onto the transfer material 202. The intermediate transfer member 209 is rotatably supported and rotated by driving a gear (not shown) which is integrally fixed.

[Sheet Feeding Unit] The sheet feeding unit is the transfer material 2 to the image forming unit.
02, and mainly includes a cassette 201 containing a plurality of transfer materials 202, a paper feed roller 203, a feed roller 204, a retard roller 205 for preventing double feed, a paper feed guide 206, and a registration roller 208. Be composed.

At the time of image formation, the paper feed roller 203 is driven and rotated in accordance with the image forming operation to separate and feed the transfer materials 202 in the cassette 201 one by one,
And reaches the registration roller 208 via the transport roller 207. During the image forming operation, the registration roller 208 performs a non-rotating operation of stopping the transfer material 202 in a standby state and a rotating operation of transporting the transfer material 202 toward the intermediate transfer body in a predetermined sequence. The image at the time of the process and the transfer material 202 are aligned.

A multi-feed tray is provided for transfer materials that cannot be fed in a cassette such as an OHT (Overhead Projector Transparency).

[Transfer Section] The transfer section comprises a transfer roller 210 which can swing. The transfer roller 210 has a metal shaft wound around a medium-resistance foamed elastic body, and is configured to be movable up and down in the figure.

While the four-color toner image is formed on the intermediate transfer member 209, that is, while the intermediate transfer member 209 rotates a plurality of times, the transfer roller 210 is not disturbed as shown by the solid line in FIG. It is located below and separated from the intermediate transfer member 209.

After the formation of the four-color toner image on the intermediate transfer member 209, the transfer roller 210 is moved upward by a cam member (not shown) by a cam member (not shown) in accordance with the timing of transferring the color image to the transfer material 202. , That is, at a predetermined pressure through the transfer material 202 against the intermediate transfer body 209.

At this time, a bias is simultaneously applied to the transfer roller 210, and the toner image on the intermediate transfer member 209 is transferred to the transfer material 202. Here, since the intermediate transfer body 209 and the transfer roller 210 are each driven, the transfer material 202 sandwiched between the two is simultaneously subjected to the transfer process,
The sheet is conveyed at a predetermined speed to the left in the drawing, and is conveyed to a fixing device which is the next step.

[Fixing Device] The fixing device 225 is provided with the developing unit 2 described above.
A fixing roller 226 for applying heat to the transfer material 202, as shown in the figure, fixes the toner image formed on the transfer material 202 via the intermediate transfer member 209 to the toner image formed by the transfer media 20 and 221. And a pressure roller 227 for pressing the transfer material 202 against the fixing roller 226. Each roller is a hollow roller and has heaters 228 and 229 inside thereof.
2 are conveyed.

That is, the transfer material 202 holding the toner image
Is conveyed by the fixing roller 226 and the pressure roller 227, and is also heated and pressed to fix the toner on the transfer material 202.

[Image Forming Operation] Next, the operation when an image is formed by the controller and the engine configured as described above will be described. Upon receiving a predetermined command from the controller 101, the engine performs a printer operation. The image data is supplied from the video interface 110 to the engine. The operation of the following hardware is controlled by the CPU on the engine side.

First, the paper feed roller 203 shown in FIG. 6 is driven to rotate, and the transfer material 202 in the paper feed cassette 201 is separated one by one and conveyed to the registration roller 208.

On the other hand, the image carrier 215 and the intermediate transfer body 209
Are rotated in the direction of the arrow shown in the figure, and the surface of the image carrier 215 is uniformly charged by the charging means 217, and the
30 irradiates the yellow image with light, and the image carrier 215
A yellow latent image is formed thereon. At the same time as the formation of the latent image, the yellow developing device 220Y is driven to apply a voltage having the same polarity and substantially the same potential as the charging polarity of the image carrier 215 so that the yellow toner adheres to the latent image on the image carrier 215. The yellow toner on the image carrier 215 is transferred onto the intermediate transfer member 209 by applying a voltage having a characteristic opposite to that of the toner to the intermediate transfer member 209 for performing yellow development.

As described above, the yellow toner intermediate transfer member 2
When the transfer to the image transfer unit 09 is completed, the developing rotary 223 rotates and the next magenta developing unit 220M rotates and is positioned at a position facing the image carrier 215, and magenta toner is developed in the same manner as yellow, and then cyan is developed. The formation and development of a black latent image and the transfer of the toner to the intermediate transfer member 209 are sequentially performed four times, and a color image is formed on the surface of the intermediate transfer member 209 by using four types of toners of Y, M, C, and Bk. I do.

After the color image on the surface of the intermediate transfer member 209 is formed, the transfer material 202 kept waiting by the registration roller is conveyed, and the transfer material 210 is transferred by the transfer roller 210.
02 is pressed against the intermediate transfer member 209, and simultaneously, a bias having a characteristic opposite to that of the toner is applied to the transfer roller 210.
The color image on the intermediate transfer body 209 is transferred to the transfer material 202.

The transfer material 202 that has undergone the transfer step is peeled off from the intermediate transfer member 209 and is conveyed to a fixing device 225 to fix the toner.
Is discharged onto the discharge tray 237 on the upper portion of the main body with the image surface facing downward, and the image forming operation is completed.

Now, in the engine having the above configuration, a large number of actuators and sensors are required to realize the above operations and sequences. Of the actuators and sensors required corresponding to the above units, ,
List the main ones. However, since the present invention is irrelevant to the mechanical structure, circuit configuration, detection method, and the like of each actuator and sensor, the detailed structure is omitted.

[Image Carrier Unit] A motor for rotating the image carrier 215 is required as an actuator, and is used in common with a drum motor for driving an intermediate transfer member described later.

[Developing means] A developing motor for rotating the developing rotary, a brake clutch for stopping the developing rotary, a sleeve switching clutch for transmitting power to the sleeve, a home position sensor for stopping each developing device at a predetermined position, and the like. Need.

[Intermediate Transfer Body] A drum motor for rotating the intermediate transfer body, a top position sensor for detecting a writing start position of an image in the sub-scanning direction, and the like are required.

[Paper Feeding Unit] In this portion, there are no paper,
A number of sensors are provided for detecting whether or not the sheet is being transported to a fixed position. Normally, a paper feed motor, many paper presence / absence sensors for each cassette / multi paper tray, paper size sensor, paper remaining amount sensor, paper thickness sensor, OH
A T sensor, a paper feed clutch, a pickup solenoid, a registration sensor, a separation jam sensor, a face-up solenoid, and the like are provided.

[Transfer Section] A transfer roller swing solenoid that swings the transfer roller is provided as an actuator.

[Fixing Device] A fixing motor is provided as an actuator, and a sensor is provided with a fixing driving clutch for controlling sheet conveyance during fixing, a fixing sheet discharging sensor, a temperature detecting thermistor, and the like.

In general, fixing by heat is controlled so that the actual recording operation is prohibited until the temperature of the fixing unit rises to a predetermined temperature. The temperature detection thermistor or the like is used for this control.

In addition to the above actuators, a scanner motor, a beam detector, a fan motor, a toner absence sensor,
Various actuators and sensors, such as a photosensitive drum life sensor, are provided.

[0047]

In the image forming apparatus having the above-described structure, a process check by an actual test print in which consumables are mounted by a pseudo controller (an image forming apparatus having a partial function of the controller) by an engine manufacturer. In spite of the fact that the controller manufacturer shipped the image forming apparatus after receiving the supply of the engine, the actual test print with the consumables was carried out again, It took time.

In the process of loading and testing the consumables and extracting the consumables after the test, troubles such as forgetting to remove the consumables and tools have occurred.

In order to solve these problems, a test print is executed without moving the movable portion by outputting a horizontal synchronization signal or a pseudo signal of a vertical synchronization signal generated from the movable portion on the engine side to the controller from the engine. A paperless print test has been proposed.

However, in the image forming apparatus having the above-described configuration, the condition in which the engine is in the ready state for the paperless print test matches the condition necessary for the normal printing operation. In this case, the paperless print test could not be started before preparing consumables such as print paper.

Conventionally, in order to confirm that image data is correctly transmitted between the controller and the engine, a configuration is provided in which a CRC code generation circuit is provided on the controller side and a CRC code check circuit is provided on the engine side. Are known. However, such an image data check mechanism has a drawback that the configuration is complicated and the load on the control circuit is increased, so that the cost of both the controller and the engine is increased.

An object of the present invention is to provide an image forming apparatus of this type which can perform a paperless print test quickly and reliably.

[0053]

According to the present invention, there is provided a controller for converting input image data into bitmap image data and supplying the bitmap image data to a printer engine, and a controller input from the controller. Control means for detecting a predetermined condition required for a normal printing operation and prohibiting the normal printing operation when the predetermined condition is not satisfied in an image forming apparatus having a printer engine for performing printing control based on image data And an operation of the first control means during a paperless print test executed by performing predetermined communication between a controller and a printer engine without mounting consumables such as a photosensitive drum, a developing cartridge and print paper. The configuration in which the second control means for invalidating is provided. According to another configuration of the present invention, a controller that converts input image data into bitmap image data and supplies the image data to a printer engine, and a printer engine that performs recording control based on image data input from the controller And an image forming apparatus having test means for testing an image signal transmitted between the controller and the printer engine. The printer engine further includes means for generating image data of a predetermined pattern on the printer engine side. A configuration is employed in which image data of a predetermined pattern is transmitted, and the image signal transmitted between the controller and the printer engine is tested by comparing the image data generated by the generating means on the printer engine side. According to another configuration of the present invention, an output unit that outputs a ready signal to an external device, an input unit that inputs image data output from the external device in response to the ready signal, and the input unit A recording mode for recording an image corresponding to the image data input by the first and second modes, wherein a first mode for inhibiting the output of the ready signal when a predetermined condition necessary for the recording operation is not satisfied; And a second mode for allowing the output of the ready signal even when the predetermined condition necessary for the second mode is not satisfied, and when the image data is input from the external device when the second mode is set. In this configuration, the input image data is inspected without executing the recording operation.

[0054]

Embodiments of the present invention will be described below with reference to the drawings.

[Embodiment 1] FIG. 1 shows a first embodiment of the present invention. In the present embodiment, in order to perform the paperless print test at high speed and reliably, the conditions under which the engine enters the print ready state for the paperless print test are different from the conditions necessary for a normal printing operation.

For example, in a normal recording mode, the actual recording operation is not performed until the temperature of the fixing unit rises to a predetermined temperature or if any of the printing paper or the toner cartridge is missing. However, in the present embodiment, during the paperless print test,
The print ready state is maintained even if the fixing unit is being heated, and even if one or both of the printing paper and the toner cartridge are missing.

In FIG. 1, reference numeral 11 denotes a CPU of the printer engine 111, which controls each part of the engine shown in FIG. At the time of a normal recording operation, necessary states of various sensors are input, and if printing is possible, the controller 101 is notified of the state. Here, for the sake of simplicity, only a configuration for detecting the temperature of the fixing unit, the presence or absence of a sheet, and the presence or absence of a toner cartridge is shown.

That is, a thermistor 12 for monitoring the temperature of the fixing unit (225 in FIG. 6), a switch 13 for monitoring the presence or absence of a sheet, and a switch 14 for monitoring the presence or absence of a toner cartridge are provided. Switch 13,
Reference numeral 14 includes a limit switch, a photo sensor, and the like.

The resistance value of the thermistor 12 changes depending on the temperature, and the temperature change can be converted into a voltage change by dividing the power supply voltage with a resistor. The voltage of the thermistor 12 is connected to the input of an A / D converter built in the CPU 11, so that the CPU 11 can monitor the temperature of the fixing device.

In FIG. 1, reference numeral 15 denotes RDY (ready) for notifying the controller of a print ready state.
The controller monitors this signal to determine whether a printing operation is possible.

Reference numeral 16 denotes a test (TEST) signal for bringing the engine into a paperless print test state, and the engine transits to a paperless print test state via a signal line 16.

The CPU 11 has a thermistor 12 and a switch 1
3 and the state of the switch 14 are monitored, and if any one of these outputs does not satisfy the requirements necessary for normal printing, the RDY signal 15 is set to false. This is an operation in normal printing, but the test signal 16 is output by the controller to execute a paperless print test.
Is true, the CPU 11 sets the RDY signal 15 to true.

Thus, the controller can execute the paperless print test quickly and reliably without waiting for the temperature of the fixing unit to rise and without preparing consumables such as print paper.

In this embodiment, for the sake of simplicity, the requirements for the normal printing operation include the temperature rise of the fixing unit and the mounting of the paper and the toner cartridge. The paperless print test may be delayed if the requirements are not satisfied. Needless to say, the various requirements necessary for the selected normal printing operation are ignored during the paperless print test as described above, and the print ready state is maintained.

Further, by using the ready signal as in the present embodiment, the controller only has to perform data transmission while watching the ready signal, so that the control on the controller side is easy.

[Second Embodiment] FIG. 2 shows a second embodiment of the present invention. This embodiment simplifies a configuration for confirming that image data is correctly transmitted between a controller and an engine.

In FIG. 2, reference numeral 21 denotes a CPU.
It outputs 8-bit comparison data 22. Comparison data 22
Is made equal to the bus width of the video data transmitted by the controller. Reference numeral 23 denotes a controller,
The video data 24 to be checked is output. Symbol 25
Is an 8-bit comparator, where A input 8 bits and B
When the input 8 bits do not match, the mismatch output 26 is set to HIG.
H level.

The mismatch output 26 is connected to the interrupt input of the CPU 21. If a mismatch of video data occurs even once during the test, the CPU 21 stores and holds the mismatch and notifies the controller after the test.

In this embodiment, at the time of the paperless print test, the video data having a fixed value is transmitted from the controller and compared with the fixed value comparison data generated on the engine side, so that the video data is transmitted normally. Check if.

In this configuration, a CRC code generating circuit is provided on the controller side and a CRC code is provided on the engine side, as in the prior art.
There is no need to provide a code check circuit, and the state of image data transmission between the controller and the engine can be checked with a simple and inexpensive configuration.

[Embodiment 3] FIG. 3 shows a third embodiment of the present invention. This configuration also simplifies the configuration for confirming that image data is correctly transmitted between the controller and the engine.

In FIG. 3, reference numeral 31 denotes a CPU.
It outputs 8-bit comparison data 32. Comparison data 32
Is made equal to the bus width of the video data transmitted by the controller. Reference numeral 33 denotes a controller,
The video data 34 to be checked is output.

Reference numeral 35 denotes an 8-bit comparator. When the A input 8 bits and the B input 8 bits do not match, the mismatch output 36 is set to the HIGH level. The mismatch output 36 of the comparator 35 is connected to the interrupt input of the CPU 31. If a mismatch of the video data occurs even once during the test, the CPU 31 stores it and notifies the controller after the test.

Reference numeral 37 denotes a horizontal synchronizing signal generating circuit which outputs an LSYNC signal only once for each sub-scanning line.
The LSYNC signal output from the horizontal synchronization signal generation circuit 37 is also connected to the interrupt input of the CPU 31, and the CPU 31 updates the comparison data 32.

In the present embodiment, during the paperless print test, the controller transmits video data that changes in a predetermined pattern in sub-scanning line units,
On the engine side, in synchronization with the horizontal synchronizing signal generation circuit, the comparison data generated by the engine is similarly changed in a predetermined pattern for each sub-scanning line and compared with the input image signal.

With such a configuration, it is not necessary to provide a CRC code generation circuit on the controller side and a CRC code check circuit on the engine side as in the prior art. The status of data transmission can be checked.

[Fourth Embodiment] FIG. 4 shows a fourth embodiment of the present invention. This configuration simplifies the configuration for confirming that image data is correctly transmitted between the controller and the engine.

In FIG. 4, reference numeral 41 denotes an 8-bit counter, and this counter 41 may be an up counter or a down counter. The number of bits of the counter 41 matches the bus width of the video data transmitted by the controller. The counter 41 has a CL for initializing the counter.
It has an R input and an EN input for performing a count operation.

Reference numeral 42 denotes an 8-bit output of the counter 41, and the output value is updated when VCLK transmitted from the controller 46 is input.

Reference numeral 43 denotes a carry output of the counter 41.
When the counter 41 is an up counter, the 8-bit output 42 becomes HIGH when the FF (hexadecimal number) is output, and when the counter 41 is a down counter, 8 bits are output.
It goes high when the bit output 42 goes to zero.

Reference numeral 44 denotes a horizontal synchronizing signal generation circuit.
The horizontal synchronizing signal generation circuit 44 outputs L for each sub-scanning line.
The SYNC signal is output only once.

Reference numeral 45 denotes a NOR gate. The output of the NOR gate 45 is supplied from the horizontal synchronizing signal generation circuit 44 to LS.
When the YNC signal is output or the carry output 43 becomes HIGH level, the level becomes LOW level, and the counter 41 is initialized. When the counter 41 is an up-counter, the counter 41 is initialized.
When 2 is 0 and the counter 41 is a down counter, the 8-bit output 42 is FF (hexadecimal).

The counter 41 can be initialized by the NOR gate 45 at the beginning of one main scan or when all 8-bit video data has been checked.

A controller 46 outputs video data 47 to be checked. Video data 47
Is output in synchronization with the video clock VCLK, and the validity of the video data is indicated by the VDOEN signal.

Reference numeral 48 denotes an 8-bit comparator. When the A input 8 bits and the B input 8 bits do not match, the mismatch output 49 is set to the HIGH level. Unmatched output 4
Reference numeral 9 is connected to an interrupt input of the CPU. If a mismatch of video data occurs at least once during the test, the CPU stores and holds the mismatch, and notifies the controller 46 after the test.

In this embodiment, at the time of a paperless print test, the controller transmits video data that changes in a predetermined pattern in pixel units in the main scanning direction, and the engine generates the video data in synchronization with the clock. The comparison data is changed for each pixel in the main scanning direction and is compared with the input image signal.

With such a configuration, it is not necessary to provide a CRC code generation circuit on the controller side and a CRC code check circuit on the engine side as in the prior art. The status of data transmission can be checked.

As described above, in the first embodiment, during the paperless print test, even if the requirements necessary for the normal printing operation are missing, they are ignored, and the print ready state is maintained. It is possible to execute the paperless print test quickly and reliably without waiting for the temperature to rise and without preparing consumables such as print paper.

Also, as shown in the second to fourth embodiments, the comparison data generating means is provided on the engine side, and the video data corresponding to the comparison data output by the comparison data generating means is output from the controller side. The connection of video data between the controller and the engine can be easily confirmed with a simple and inexpensive configuration.

[0090]

As is apparent from the above description, according to the present invention, the first condition for detecting the predetermined condition necessary for the normal recording operation and prohibiting the normal recording operation when the predetermined condition is not satisfied. A control unit, and a first control unit for performing a paperless print test performed by performing predetermined communication between a controller and a printer engine without mounting consumables such as a photosensitive drum, a developing cartridge, and printing paper. By providing the second control means for disabling the above operation, it is possible to immediately start the paperless print test at the time of the paperless print test even if the predetermined condition necessary for the recording operation is not satisfied. For example, the controller required for normal printing operation can execute the paperless print test quickly and reliably without waiting for the temperature of the fixing device to rise and without preparing consumables such as print paper.

According to the present invention, a means for generating image data of a predetermined pattern is provided on the printer engine side, and the image data of the predetermined pattern is transmitted from the controller side to the printer engine. By testing the image signal transmitted between the controller and the printer engine by comparing the image signal generated by the generating means on the engine side, a check circuit using a CRC code, which was conventionally required, is not required, so that it is simple. With a low-cost configuration, it is possible to easily execute a connection check regarding video data between the controller and the engine.

Further, according to the present invention, it is possible to easily control whether or not to ignore a test result of a predetermined condition required for recording via a ready signal transmitted and received between the controller and the engine. The advantage is that no special configuration is required on the side.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration for controlling requirements of a printing operation in an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration for testing image data transmission between a controller and a printer engine in a second embodiment of the image forming apparatus of the present invention.

FIG. 3 is a block diagram showing a configuration for testing image data transmission between a controller and a printer engine in a third embodiment of the image forming apparatus of the present invention.

FIG. 4 is a block diagram showing a configuration for testing image data transmission between a controller and a printer engine in a fourth embodiment of the image forming apparatus of the present invention.

FIG. 5 is a block diagram illustrating a configuration of a control system of the color laser beam printer.

FIG. 6 is a cross-sectional view illustrating a hardware configuration of an engine of the color laser beam printer.

[Explanation of symbols]

 11, 21, 31 CPU 12 Thermistor 13 Switch 14 Switch 37 Horizontal synchronization signal generation circuit 41 Counter 43 Carry output 44 Horizontal synchronization signal generation circuit 45 NOR gate 23, 33, 46, 101 Controller 111 Printer engine

Claims (3)

[Claims] An image forming apparatus comprising: a controller that converts input image data into bitmap image data and supplies the image data to a printer engine; and a printer engine that performs recording control based on the image data input from the controller. A first control unit for detecting a predetermined condition necessary for the normal recording operation and prohibiting the normal recording operation when the predetermined condition is not satisfied; And a second control unit for invalidating the operation of the first control unit during a paperless print test executed by performing predetermined communication between the controller and the printer engine. Forming equipment. 2. A controller that converts input image data into bitmap image data and supplies the image data to a printer engine, a printer engine that performs recording control based on the image data input from the controller, and a controller and the printer engine. An image forming apparatus having test means for testing an image signal transmitted by the printer engine, wherein a means for generating image data of a predetermined pattern is provided on the printer engine side, and the predetermined pattern of the predetermined pattern is provided from the controller side. An image forming apparatus for transmitting image data, and testing an image signal transmitted between a controller and a printer engine by comparing the image data with an image signal generated by the generating means on a printer engine side. 3. An output unit for outputting a ready signal to an external device, an input unit for inputting image data output from the external device in response to the ready signal, and an image data input by the input unit. Recording means for recording a corresponding image, wherein a first mode for prohibiting the output of the ready signal when a predetermined condition necessary for the recording operation is not satisfied, and a predetermined mode necessary for the recording operation being satisfied. A second mode that permits the output of the ready signal even when the image data is not input, and when the image data is input from the external device when the second mode is set, a recording operation is performed. Not
An image forming apparatus for inspecting input image data.