JPH09179454A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device preventing the lowering of a service life and the waste of energy by putting a printing means in a stand-by state when a stand-by judging means judges that the printing means should be put in the stand-by state. SOLUTION: After the start of image processing by a processing means, a stand-by state judging means judges whether to put a printing means in a printing state or a stand-by state, and in the case of judging the stand-by state, a printing control means puts the printing means in the stand-by state. The stand-by state is a state of stopping the parts of the printing means other than a part that can be left operated as well as taking long time for rising at the time of resuming operation. In the case of taking a bit map control part 30 long time to describe an image to BM-RAM 32, for instance, an electrophotogrphic processing part 45 also remains in an action state so as to shorten the service life of a photosensitive drum and each electrophotogrphic processing part. In such a case, the printing means is put in the stand-by state to improve the lowering of service life of the image processing part of the printing means in large degree.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improving throughput in an image forming apparatus.

[0002]

2. Description of the Related Art In a page printer that prints received data page by page, the received data for one page is converted into an intermediate code for printing and then printed. Done. The print engine continues to wait until the conversion is complete. When the conversion is completed, the paper is fed, and the paper is waited for until it reaches the printing means to print.
Therefore, there is a wasteful time required to convey the paper from the end of conversion to the start of printing. For this reason,
When printing a large amount of data at high speed, this wasteful time accumulates and cannot be ignored. On the other hand, in a line printer that prints line by line, character printing is performed even during data processing. When it takes a long time to draw one page of received data into bitmap data, the print engine continues to wait until the conversion is completed, and the electrophotographic process unit of the printer remains in the operating state. I will end up. Therefore, there is a problem that the life of each part of the photosensitive drum and the electrophotographic process is shortened.

An object of the present invention is to provide an image forming apparatus which prevents a reduction in life and waste of energy.

[0004]

An image forming apparatus according to the present invention includes an input means for inputting image information, a processing means for processing the input image information into image information to be printed, and the processing means. Output control means for exposing the photosensitive member on the basis of processed data; printing means for printing a latent image on the photosensitive member on paper by an electrophotographic process; conveying means for supplying the paper to the printing means; It is also possible to provide a printing state in which the printing means is operated in a printable state after the image processing is started by the processing means, and further, the rising time at the time of re-operation of the printing means may be long and operated. The standby determination means for determining which one of the standby states should stop other than the part, and the standby determination means determines that the standby state should be set. Occasionally, and a print control means for controlling so that said printing means and said standby state. This image forming apparatus includes a printing unit that prints a latent image on a photoconductor on a paper by an electrophotographic process. The standby state determination unit determines whether the print state or the standby state should be set after the image processing by the processing unit is started, and the print control unit determines that the standby determination unit should be set in the standby state. Sometimes, the printing means is put in the standby state. The standby state is a state in which all of the printing means other than the part that may be activated and has a long rise time at the time of reactivation is stopped. For example, in the embodiment of the invention, the fixing unit and the cooling fan are parts of the printing unit that have a long rise time at the time of re-operation and may be operated, and these are also operated in the standby state. However, as shown in FIG. 13, the main motor, the main charger, etc. are stopped in the standby state.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in the following order with reference to the accompanying drawings. a. Configuration of electrophotographic printer b. Bitmap control flow c. Interface control flow d. Flow of electrophotographic control e. Print head control flow

(A) Configuration of Electrophotographic Printer FIG. 1 is a configuration of a processing system by a printer system 10 capable of graphic drawing according to an embodiment of the present invention. Data from the general-purpose data processing device 1 is output to the printer system 10 after being stored in the file buffer 2 in order to improve the throughput of the data processing device 1. The printer system 10 includes a bitmap data processing device 3, a print engine 4 using an electrophotographic process and a laser, and an external paper feeding unit 5.
It consists of ancillary equipment such as a and a sorter 6.

FIG. 2 is a schematic block diagram of the control of the printer system 10. The bitmap type data processing device 3 includes a bitmap control unit 30 (see FIG. 3), a bitmap BM-RAM 32, a bitmap writing unit 31 (see FIG. 4) for drawing on the BM-RAM 32, and a font unit. It consists of 33. The connection with the print engine 4 is made by a bus B3 for control data (number of sheets, accessory control, etc.) and a bus B4 for image data. The print engine 4 is composed mainly of three controllers. First, the interface control unit 40 processes the control data from the bitmap control unit 30, controls the display panel, and controls the timing of the entire printer 4 through the internal bus B5. The electrophotographic control unit 41 (see FIG. 6) controls the electrophotographic process unit 45 according to the data sent from the interface control unit 40 through the internal bus B5. The print head control unit 42 (see FIG. 7) prints the image data sent via the bitmap writing unit 31 and the internal bus B4 according to the information sent from the interface control unit 40 via the internal bus B5. It is applied to the semiconductor laser 431 of the section 43 (see FIG. 7) to control the light emission of the semiconductor laser 431 and the rotation of the polygon motor 432. The external paper feeding unit 5 and the sorter 6 are also controlled by the interface control unit 40 via the internal bus B5.

FIG. 3 is a block diagram of the bitmap controller 30. The bitmap control unit 30 uses the internal bus B3
It is composed of several blocks connected by 01. The BM-CPU 301 is a central control unit of the bitmap type data processing device 3, performs communication with the data processing device 1 through the data processing device interface 308, converts print data, and outputs a bitmap writing unit interface. The bitmap writing unit 31 is controlled through 306, and the print engine 4 is controlled through the print engine interface 307. SY
The S-ROM 302 stores the program of the BM-CPU 301. The SYS-RAM 303 is a BM-CPU3.
This is a working storage area 01 and is used for storing stacks and basic flags. The R-buffer 304 is a buffer for communication with the data processing device 1, and is intended for asynchronous communication between the processing program of the BM-CPU 301 and the data processing device 1. The P-RAM 305 stores the attributes of each font loaded by the bitmap writing unit 31 from the font unit 33 and the data from the data processing device 1 as an intermediate code converted from the font attributes for printing. The print engine interface 307 is an interface with the print engine 4, and has JOB information such as the number of prints and J information such as print commands.
OB control commands are exchanged with the interface of the print engine 4 through the bus B3.

FIG. 4 is a detailed block diagram of the bitmap writing unit 31. The function of the bitmap writing unit 31 is roughly divided into a drawing function to the BM-RAM 32 and a function to output the data of the BM-RAM 32 to the print engine 4 at the time of printing. The function of drawing on the BM-RAM 32 is further divided into two, and is composed of line and circle drawing performed by the graphic image writing unit 316 and font drawing performed by the font image writing unit 311. Although both are logic units that operate on the intermediate code sent from the bitmap control unit 30 through the bitmap control unit interface 317, most of the processing of the graphic image writing unit 316 analyzes the parameters in the intermediate code and uses the BM. In contrast to drawing in the RAM 32, most of the processing of the font image writing unit 311 draws in the BM-RAM 32 the font image read from the font unit 33 through the font unit interface 314 according to the data in the intermediate code. On the other hand, the function of outputting data during printing is performed by the print head controller interface 315. That is, when the print start code sent from the bitmap control unit 30 via the interface 317 is received, according to the synchronization signal sent from the print head control unit 42 (see FIG. 8) of the print engine 4 via the bus B4, The data in the BM-RAM 32 is output to the print head controller 40.

FIG. 5 is a detailed block diagram of the interface control unit 40 of the print engine 4. The interface control unit 40 is mainly composed of an IFC-CPU 400 using a one-chip microcomputer, and an external ROM 4 via a bus B 401 expanded by an interface 404 of the IFC-CPU 400.
07, RAM 408, and bitmap control unit 30
And an interface 409 are connected. External R
OM407 can be replaced by a socket,
In the mask ROM 403 inside the IFC-CPU 400,
Standard program is stored, but external RO
M407 stores different programs depending on the destination. The IFC-CPU 400 includes a CPU 401, RA
In addition to M402 and ROM403, a serial input / output unit (SIO) 405 for serial communication and a parallel input / output unit (PI
O) 406 is built in. The SIO 405 controls the bus B5 for controlling the electrophotographic control unit 41 and the print head control unit 42. The PIO 406 is used to control the display panel 44.

FIG. 6 is a detailed block diagram of the electrophotographic control unit 41. The electrophotographic control unit 41 uses the IFC-CPU 4
One-chip microcomputer MC similar to 00-
It is controlled by the CPU 410. The CPU 411 has a RAM
413 and ROM414 are connected. Unlike the interface control unit 40, only the standard program is not expanded. The serial input / output unit (SIO) 412 communicates with the interface control unit 40 via the bus B5. The parallel input / output unit (PIO) 415 is used for input / output of process control. FIG. 7 is a detailed block diagram of the printhead controller 42. In the print head controller 42, the bus B5
The rotation of the polygon motor 432 of the print head unit 43 is controlled in accordance with the data sent from the interface control unit 40 through the, or the image data sent from the bitmap data processing device 3 through the bus B4. Laser scanning scanning detector (SO
S) in synchronization with the signal from the semiconductor laser 431.
Control the emission of light.

The print head control unit 42 is mainly composed of a one-chip microcomputer PHC-CPU 420 like the electrophotographic control unit 41, and the serial input / output unit (SIO) 422 has an interface control unit 40.
A bus B5 for communicating with is connected. The parallel input / output unit (PIO) 425 includes a polygon motor driving unit 427 that drives the polygon motor 432, and a scanning detector (S).
OS) 433 and a print head control circuit 426 for controlling the light emission of the semiconductor laser according to the image data from the bitmap type data processing device 3. The image data sent via bus B4 is
In the parallel format, the printhead control circuit 426 mainly performs parallel-serial conversion for causing the semiconductor laser 431 to sequentially emit light in accordance with image data. However, for the printhead control unit interface 315 of the bitmap writing unit 31, It also generates a timing signal for synchronizing the image data transfer.

(B) Flowchart of Bitmap Control The operation of this system will now be described with reference to the flowchart. 8 to 10 are flowcharts showing the processing of the bitmap control unit 30. In FIG. 8, when the power is turned on (step # 100), internal initialization is performed (step # 101), and the received data from the BM-RAM 32, which is the print image area, and the data processing device 1 is converted into an intermediate code. P-R that stores the converted value
AM 305, a JOBACT flag indicating that a print operation is in progress, and B indicating a write state of the BM-RAM 32.
Reset the M-WRITE flag (step # 10
2) Then, the font attributes are read from the font section 33 (step # 103). As described in section (d), the electrophotographic control unit 41 controls the temperature of the fixing unit and starts the cooling fan (step # 301 in FIG. 14, standby mode 1). Next, the reception data processing loop is entered. The first processing is processing of received data. First, P-RA
It is checked whether or not there is a free space in M305 (step # 104). If there is a space, the interrupt processing routine shown in FIG.
Data processing device 1 stored in R-buffer 304
The received data from is extracted (step # 105, step # 106), and the process corresponding to the code (see FIG. 9) is performed (step # 107).

FIG. 9 shows received data processing (step 8 in FIG. 8).
The content of 107) is shown. There are four types of received data: print engine related code, JOB control code, format control code and print code. Of these, the print engine related code is the interface control unit 40.
(Step # 151, step # 152). J
For the OB control code, PAGE used for page breaks
There are two types, the EJECT code and the JOBSTART code used for dividing the JOB (one page group). The JOB control code has a P-RAM 305 as a corresponding flag.
It is stored in (steps # 153 to # 156). In the case of the format control code (step # 157), the write address of the next character to the BM-RAM 32 is changed (step # 158). The other received data is regarded as a character code, converted into an intermediate code for writing to the bitmap writing unit 31, and written in the P-RAM 305. The format of the intermediate code is font address (step # 159), BM
-It consists of a write address (step # 160) and a write mode (step # 161) to the RAM 32. After this, depending on the font size, etc., the BM of the next font
-Change the write address to the RAM 32 (step # 162). However, it does not change when drawing lines or circles.

Returning to FIG. 8, the intermediate code written in the P-RAM 305 indicates that the BM-RAM 32 is not in use for printing (NO in step # 108) and is not in multi-printing (step ##). No in 109), and the data is output to the bitmap writing unit 31 (step # 116).
However, while the previous character is being drawn (YES in step # 110), the next drawing cannot be performed. If writing the first data (BM-WRITE flag = 0)
(YES in steps # 111 and # 112), BM-WRI
The TE flag is set to 1 (step # 113), and the paper advance command PFCMD for advancing preparations such as paper feeding to the print engine 4 is output to the interface control unit 40 (step # 114). As a result, when the print preparation of the bitmap type data processing device 3 is completed (steps # 305 to # 311 in FIG. 14), laser exposure to the photoconductor is immediately possible, and the throughput is improved corresponding to the paper feeding time.

The output from the P-RAM 305 to the bit map writing unit 31 is sequentially performed as long as there is intermediate code data, but when the PAGEJECT code is detected (YES in step # 115), the signal for one page is output. Since the conversion is completed, the printing operation is started. First, BM-RA
The JOBACT flag is set to prohibit writing to the M32, updating of the BM-RAM 32 is prohibited (step # 117), and the printhead controller interface 3
15 is set to a printable state (step # 118), and a print command PRNCM is sent to the interface control unit 40.
D is output (step # 119). As a result, in the printhead control unit interface 315, the data in the BM-RAM 32 is transferred to the bus B4 in synchronization with the pulse sent from the control circuit 426 of the printhead control unit 42.
Output through During the print operation, the operation check of the print head control unit interface 315 results in YES in step # 108. Therefore, the process of converting the received data and outputting it to the P-RAM 305 for the next print (steps # 104 to # 107). ) Only is done.

When printing is completed, JOBACT is still
Since the flag is set, the process proceeds from step # 109 to step # 120, and the exposure end command EXPEND from the interface control unit 40 (FIG. 15 step #
413) Wait. This is because the interface control unit 40 controls the number of sheets in the case of multi-printing. JOB which is a parameter of this command
If the END flag is set (step # 12
1), reset the JOBACT flag, BM-RAM
32 is cleared (step # 122), and preparation for printing the next page is started. If the multi-print is not completed, the next print is started with the same BM-RAM data (step # 118 and thereafter). FIG. 10 shows a flow when there is an interrupt of data transmission from the data processing device 1. When there is an interrupt, the data is read from the data processing device 1 (step # 181) and written in the R-buffer 304 of the bitmap control unit 30 (step # 182). Then return.

(C) Interface Control Flow FIG. 11 is a processing flow of the interface control unit 40. In the interface control unit 40, after the power is turned on and the internal initialization is performed (step # 201), the electrophotographic control unit 41, the print head control unit 42, the sorter 6 and the external paper feeding unit 5 are activated via the bus B5. A signal is sent to initialize the entire system of the print engine 4 (step # 202). Then, the initial value 1 of the PFENB flag indicating permission of paper feed-out is set (step # 203), and the processing loop below is entered. In the processing loop, first, the process waits for the advance command PFCMD (see step # 114 in FIG. 8) from the bitmap control unit 30.
(Step # 204). When the first-out command is received and the first-out command is permitted (PFENB = 1), (step # 2
(YES in 05), the electrophotographic control unit 41 through the bus B5
The paper feed request signal FEEDREQ is output to (step #
206). As a result, the electrophotographic control unit 41 starts the activation of the electrophotographic process unit 45 for feeding and printing. However, the paper goes into a standby state (“first-out” state) at a predetermined position. However, when the external paper feeding unit 5 is designated, the electrophotographic control unit 41 only activates the electrophotographic process unit 45, and the paper feeding is performed by the external paper feeding unit 5. Note that the paper standby position is the same.

Then, the interface controller 40 waits for the print command PRNCMD (step # 2).
At the same time as 11), a temporary value 1 is set to the NPFENB flag indicating permission for the next print advance, and a predetermined timer T is started (step # 207). This timer T has two functions. First, when the bitmap control unit 30 draws on the BM-RAM 32 for a long time, the electrophotographic process unit 45 also remains in the operating state, and the life of the photosensitive drum and each unit of the electrophotographic process is reduced. In order to prevent the print engine 4 from becoming short, the STANDBY signal is sent (step # 209) when the timer T ends (YES in step # 208), and the print engine 4 is stopped (standby mode 2). As a result, the reduction in the life of the image forming process unit is greatly improved. Once the standby mode 2 is entered, the next paper feeding and activation of the image forming process will be performed after the conversion of the received data into the intermediate code is completed. Another function is to inhibit the first-out of the paper at the time of the next printing by resetting the NPFENB flag indicating the next first-out permission (step # 210). This is because the same type of information is usually printed frequently in one JOB (for example, graphic data is continuously printed), and this is predicted, and it has the effect of preventing a decrease in life. With this method, the throughput will be reduced, but even if the paper feed-out is prohibited once, the print command PRNC will be printed before the timer T expires during the next printing.
When MD is input, the NPFENB flag remains set, so that the first print is performed in the next print. (Usually, the paper is “first out” before the data conversion is completed and the timing roller keeps it on standby, so the throughput does not decrease.) By the above two functions, it is possible to improve the throughput and at the same time prevent the life from decreasing. Become.

The interface controller 40 receives the print command PRNCMD (step # 211).
YES), if the paper is not advanced (PFE
NB = 0) (YES in step # 212), the paper feed request signal FEEDREQ is output (step # 213), and the PFENB flag of the next print is updated (step # 213).
214). That is, when the print data is generated, the paper feeding is executed (FIG. 14, step # 304, step # 304).
321, steps # 307 to # 311), the paper is conveyed to a predetermined position. Further, the STANDBY signal is turned off (step # 215), that is, the standby mode 2 is released, and the MCRDY signal indicating that the image forming process unit of the electrophotographic control unit 41 is stable is the electrophotographic process unit 45.
From the device (YES in step # 216), the EXPENB signal indicating the exposure permission is output (step # 2).
17). As a result, the actual exposure is performed by the print head controller 42. Upon completion of exposure, the print head controller 42 outputs an EXPEND signal (FIG. 15).
See step # 413). Interface control unit 40
When this is detected (step # 218), the EXPEND command is output to the bitmap control unit 30.
(Step # 219), the paper advance command P again
Waiting for FCMD.

FIG. 12 shows a timing chart of printing. Here, X is the time from the activation of the main motor of the electrophotographic process unit 45 until it is stabilized, and Y is
This is the time required from the start of paper feeding to the arrival at the timing roller (standby position). Conventionally (lower side), the paper is stopped by the timing roller for at least time Z. In the present embodiment (upper side), since the paper is conveyed to the timing roller in advance, an extra waiting time is eliminated and printing is completed faster than in the conventional case (lower side). Although the printer is started when the print data is generated, the display panel may notify that the printer is selected. FIG. 13 shows the operation timing of the image forming process unit in the present embodiment in comparison with the conventional example. As shown in the figure,
When it takes a long time to convert the data (timer T times up), the main motor is stopped and the standby mode 2 is set. At this time, the main charger and the developing bias voltage are sequentially stopped before the main motor is stopped.
The interface control unit 40 controls communication in the print engine 4 in addition to the control described above. Data is exchanged with each control unit via the bus B5, and at the same time, a relay function for communication between the control units is also provided. However, since it is not directly related to the present invention, detailed description will be omitted.

The effect of the advance timing control in the present embodiment has been described for the conversion time of the received data to the intermediate code and the drawing time in the bitmap writing unit 31 is long. Even if the drawing time is short, the same effect can be obtained if the transmission time from the data processing device 1 or the file buffer 2 is long. Further, in the present embodiment, the throughput is prioritized,
The paper advance control is performed, but switching means for selecting whether or not to perform the paper advance control may be provided, and in the case of graphic processing, the drawing processing may be prioritized and the advance control may not be performed.

(D) Flow of electrophotographic control FIG. 14 is an operation flow of the electrophotographic control unit 41. In the electrophotographic control unit 41, after turning on the power (step # 300),
After performing internal initialization (step # 301), a start signal from the interface control unit 40 (step # 301 in FIG. 11).
The input is awaited (see # 202) (step # 302). When the activation signal is detected (step # 302), the paper advance command PFCMD is issued from the interface control unit 40.
(See step # 114 in FIG. 8), the paper feed request signal F is received.
Until EEDREQ is output (step # 304), the standby mode 1 is set in the waiting state (step # 303). In the standby mode 1, the main motor and the drum are not rotated, and only the temperature control of the fixing unit and the turning on of the cooling fan are performed. When the paper feed request signal FEEDREQ is received (step # 304), the image forming process unit is started for printing, the main motor is turned on (step # 305), and the interface control unit 40 indicates that the preparation is completed.
Output DY signal (step # 306) and start feeding
(Step # 307). A predetermined timer T ₁ is set at the same time as the feeding is started (step # 308), the timer T ₁ ends, and when the paper approaches the predetermined standby position.
(Step # 309), the PRDY signal indicating that the preparation of the paper is completed is output to the print head controller 42 (step # 310), and the paper conveyance is stopped (step # 311).

Normally, the print command (PRNCMD) is immediately output from the bitmap control unit 30 (see step # 119 in FIG. 8), and then the print head control unit 4
From 2, the paper restart signal TRON is output.
By detecting this signal by the electrophotographic control unit 41 (see step # 411 in FIG. 15) (step # 318), the paper is restarted from the position of the timing roller.
(Step # 319), the image on the photosensitive drum is transferred to paper. After that, in the electrophotographic control unit 41,
Further, a predetermined timer T ₂ is set (step # 3
20), waiting for the next sheet feeding request signal FEEDREQ (step # 321), and when the signal is input, the next sheet feeding is started (step # 306). If no signal is input by the end of timer T ₂ (YES in step # 322)
Returns to the standby mode 1 (step # 303). If the processing time in the bitmap control unit 30 or the transmission time from the data processing device 1 is long, the print head control unit 4
When the TRON signal is not output from 2 (when the print command is not output from the bitmap control unit 30 to the interface control unit 40), the STANDBY signal is output from the interface control unit 40.
(See step # 209 in FIG. 11). When the electrophotographic control unit 41 detects this signal (step # 312), it turns off the MCRDY signal to the interface control unit 40 (step # 313) and enters the standby mode 2 (step # 31).
4). In the standby mode 2, all processes including the main motor are stopped, and the paper is also in the standby state at the standby position. This is to prevent the life of the printer from being unnecessarily shortened. Thereafter, the signal conversion processing in the bitmap control unit 30 is completed, and the interface control unit 40
When the STANDBY signal is turned off in step S3, the electrophotographic control unit 41 detects this (step # 315), restarts the image forming process unit (step # 316), and outputs the MCRDY signal to the interface control unit 40 again. Output (step # 317).

(E) Print Head Control Flow FIG. 15 shows a processing flow in the print head controller 42. The print head controller 42 initializes the inside (step # 40) after the power is turned on (step # 400).
1) Similarly to the electrophotographic control unit 41, after detecting the activation signal (see step # 202) from the interface control unit 40 (step # 402), the process loop is started. In the processing loop, first, the print start waits. There are two conditions for starting printing. One is a laser exposure permission signal EXPE from the interface control unit 40.
It is the NB (step # 406) and is output from the interface control unit 40 (see step # 217 in FIG. 11).
The other is a PMLOCK signal indicating that the polygon motor 432 has reached a predetermined rotation speed. polygon·
The motor 432 is controlled at the same timing as the main motor (step # 403), the electrophotographic control unit 41 is in the standby mode 1 or the standby mode 2, and the life of the polygon motor 432 is maintained while the main motor is stopped. To extend the rotation speed, rotate at half speed, which is about half the normal rotation speed (step #
405), when printing is started and the main motor is turned on, the normal speed is the full speed state (step # 404).
Becomes Then, the PMLOCK signal indicating that the rotation speed is stable in the full-speed state is the polygon motor drive unit 42.
It is output from 7. When the two conditions are satisfied (YES in step # 406 and step # 407), a start signal is sent to the print head control circuit 426 to start exposure (step # 408). As a result, the print head control circuit 426 sequentially requests the image data from the bitmap writing unit 31, and controls the emission of the semiconductor laser 431 according to the received data. Further, the print head controller 42 starts two predetermined timers T ₁ and T ₂ at the same time when the exposure is started (step #
409). The timer T ₁ is a fixed timer regardless of the paper size, and restarts the paper at the standby position to control the registration timing.
When the timer T ₁ expires (YES in step # 410)
S), and outputs the paper restart signal TRON to the electrophotographic control unit 41 (step # 411). Also,
The timer T ₂ is for synchronizing with the bitmap control unit 30 and can be changed depending on the paper size.
When the timer T ₂ ends (YES in step # 412)
S), EXPEN for the interface control unit 40
The D signal is output (step # 413).

[0026]

The standby state determining means determines whether the print state or the standby state should be set after the image processing by the processing means is started, and the print control means sets the standby determining means to the standby state. When it is determined that it should be, the printing means is put in the standby state. The standby state is a state in which the printing unit is stopped except for a portion (for example, a fixing unit) which has a long rise time at the time of re-operation and may be operated. For example, in the embodiment of the present invention, when drawing on the BM-RAM 32 by the bitmap control unit 30 takes a long time, the electrophotographic process unit 45 also remains in the operating state, and the photosensitive drum and the electrophotographic process are performed. The life of each part is shortened. Therefore, in such a case, the printing means is put in the standby state, and the reduction in the life of the image forming process section of the printing means is greatly improved. When a certain number of large amount of data continues for several pages, the print engine main body does not stop every conversion process, and it is possible to prevent the power supply from being instantaneously affected by stop and re-operation.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of an electrophotographic printer according to an embodiment of the present invention.

FIG. 2 is a block diagram of a bitmap data processing device and a print engine.

FIG. 3 is a block diagram of a bitmap control unit.

FIG. 4 is a block diagram of a bitmap writing unit.

FIG. 5 is a block diagram of an interface control unit.

FIG. 6 is a block diagram of an electrophotographic control unit.

FIG. 7 is a block diagram of a print head control unit and a print head unit.

FIG. 8 is a flowchart of the operation of the bitmap control unit.

FIG. 9 is a flowchart of an operation of received data processing.

FIG. 10 is a flowchart of a reception interrupt operation.

FIG. 11 is a flowchart of the operation of the image forming process unit.

FIG. 12 is a timing chart of the operation of the image forming process unit.

FIG. 13 is a timing chart of the operation of the image forming process unit.

FIG. 14 is a flowchart of the operation of the electrophotographic control unit.

FIG. 15 is a flowchart of the operation of the printhead controller.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Data processing device, 3 ... Bitmap type data processing device, 4 ... Print engine, 10 ... Printer system, 30 ... Bitmap control unit, 31 ... Bitmap writing unit, 40 ... Interface control unit,
41 ... Electrophotographic control unit, 43 ... Print head unit.

Claims (1)

[Claims] 1. An input unit for inputting image information, a processing unit for processing the input image information into image information to be printed, and exposing on a photosensitive member based on the data processed by the processing unit. Output control means, printing means for printing a latent image on a photoreceptor on paper by an electrophotographic process, conveying means for supplying paper to the printing means, and printing of the printing means after starting the image processing by the processing means To determine whether it should be in a printing state in which it is operated in such a state, or in a standby state in which parts other than those parts of the printing means that have a long rise time at the time of re-operation and may be operated are stopped. And a control unit that controls the printing unit to enter the standby state when the standby determination unit determines that the standby state should be set. An image forming apparatus, comprising: