JP2013063563A - Write control unit and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate downtime of a machine without making control, such as timing management, complicated.SOLUTION: In a buffer control part 300a, a set value on the first page stored in a register 300 is written in an address "0" predetermined among addresses "0" to "5" of temporary storage parts 503 and 504. A set value on the second page stored in the register 300 is written in the address "1" of the temporary storage parts 503 and 504. Then, set values on the third page, the fourth page, ..., and the sixth page are written in the address "2", address "3", ..., and address "5" of the temporary storage parts 503 and 504, respectively by the same process. Then, a set value on the seventh page stored in the register 300 is written in the address "0" in which the set value on the first page is written. Reading of a set value written in each of the addresses "0" to "5" of the temporary storage parts 503 and 504 is performed by switching addresses in the order of the writing.

Description

  The present invention relates to a writing control device for controlling a writing device for writing image information onto a writing medium such as a photosensitive member by a light beam or the like in accordance with image data, a laser printer equipped with the writing control device, and digital copying. The present invention relates to an image forming apparatus such as a copier, a facsimile machine (FAX), and a digital multifunction machine (MFP).

The image forming apparatus as described above includes an image forming process unit provided with respective units for charging, exposing, developing, and transferring around a photoconductor that is an image carrier (write medium). A series of image formation (hereinafter also referred to as “printing”) processing including a simple image formation is performed.
That is, first, the surface of the drum-shaped or belt-shaped photosensitive member moving in the sub-scanning direction is uniformly charged by the charging unit. The movement of the drum-shaped photosensitive member (rotating member) in the sub-scanning direction is also referred to as “rotating” or “rotating”. Further, the movement of a member (belt member) such as a belt-shaped photoconductor in the sub-scanning direction is also referred to as “turning”.

  Next, in an optical scanning device that is an exposure unit (writing device), a light beam modulated in accordance with image data emitted from a light source is used with a deflecting unit such as a rotating polygon mirror (also referred to as “polygon mirror”). Then, the charged surface (charged surface) of the photosensitive member is repeatedly scanned (main scanning) in the main scanning direction orthogonal to the sub-scanning direction for exposure. Thereby, an electrostatic latent image (image information) by a light beam is written on the charged surface of the photosensitive member. Then, the electrostatic latent image is developed with toner from the developing unit to form a toner image, and is transferred directly to the recording medium paper by the transfer unit, or transferred onto the intermediate transfer belt and then transferred to the paper. . The sheet on which the toner image is transferred is fixed to the toner image through the fixing unit and is discharged outside the apparatus.

In an image forming apparatus that performs such print processing, a plurality of different print modes (for example, a copy mode, a printer mode, a FAX mode, and a resolution) are selectively designated, and writing control is performed according to the designated print mode. The apparatus performs various settings (such as print settings that are condition settings related to printing). The writing control device controls the writing device in accordance with the various settings and causes image information to be written to the medium to be written.
By the way, as an image forming apparatus that performs printing processing including writing image information in a plurality of different printing modes, a function of continuously printing pages with different printing modes is provided, and when using this function, There has been proposed a writing control device in which the setting is switched for each page.

  However, with such a method of switching settings, if there is a large number of register changes between pages during continuous jobs that require switching of the print mode, the software settings are not in time, and the paper spacing is expanded more than usual. . In addition, the setting timing is defined by the setting value, and setting timing management is a heavy load on the software designer, and there is a problem that the software load increases particularly between papers. “Software” refers to software (also referred to as “program”). The “software setting” is a setting by software, specifically, a setting performed by the hardware CPU according to the software.

Therefore, in order to solve such a problem, for example, it is conceivable to use a technique disclosed in Patent Document 1.
Patent Document 1 discloses a setting value (storage unit) that realizes the same function in order to realize an image forming operation corresponding to a complex continuous printing operation in which a plurality of different printing modes are continuous without causing downtime. A method of providing a plurality of group groups and switching them for each print mode is disclosed.

  However, in the device described in Patent Document 1, since the same setting register exists at a plurality of addresses, the software needs to manage what is set in the register at which address. Even in a printing mode in which only one register is different (for example, a printing mode in which any one of paper size, resolution, etc. is different), it is necessary to switch between groups. In order to cope with switching of all modes, it is necessary to increase the number of register groups, but this increases the circuit scale. Although it is conceivable to modify a part of the register group by software setting, in that case, it is necessary to manage what is set for each register group, and the software becomes complicated.

  The present invention has been made in view of the above points, and aims to eliminate downtime of a machine without complicating control such as timing management for storage means on the software side.

The present invention is a writing control device that controls a writing device that writes image information on a medium to be written, and is characterized by the following configuration in order to achieve the above object.
That is, the image forming apparatus includes storage means for storing various setting values necessary for the image information writing control and control means having N (N ≧ 2) temporary storage means. The control means writes the setting value of the first page stored in the storage means into a predetermined temporary storage means among the N temporary storage means. The setting value of the Nth page stored in the storage means is written in a temporary storage means different from the temporary storage means in which the setting values up to the (N-1) th page among the N temporary storage means are written. The setting value for the (N + 1) th page stored in the storage means is written in the same temporary storage means as the temporary storage means in which the setting value for the first page is written. Reading of the setting values written in the N temporary storage means is performed by switching the temporary storage means in the order of writing.

  According to the writing control apparatus of the present invention, the control means includes N (N ≧ 2) temporary storage means, and the setting value of each page stored in the storage means is written to each temporary storage means. Or read out. Therefore, control such as timing management for the storage means on the software side is not complicated, and machine downtime can be eliminated.

1 is a schematic diagram illustrating an example of a mechanical configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view illustrating a schematic configuration example of an optical system for exposing a photosensitive drum 104a in the optical device 102 of FIG. FIG. 2 is a block diagram illustrating a schematic configuration example of a control unit of the image forming apparatus 100 illustrated in FIG. 1. It is a block diagram which shows the structural example of GAVD310 of FIG. FIG. 5 is a block diagram illustrating a configuration example of a register 300 and a register buffer control unit 300a in FIG.

6 is a timing chart showing an example of the relationship among each address, register setting timing of each page, operation start signal STOUT_N, and sub-scan gate signal PFGATE for each color in temporary storage units 503 and 504 in FIG. FIG. 5 is a timing diagram illustrating an operation example during a continuous printing operation in the GAVD 310 illustrated in FIG. 4. FIG. 5 is a timing chart showing another operation example during a continuous printing operation in the GAVD 310 shown in FIG. 4. FIG. 5 is a timing chart illustrating an example for explaining register value reading switching timing by the register buffer control unit 300a of FIG. 4; It is a timing diagram which shows the operation example at the time of the continuous printing operation | movement in the conventional GAVD.

  Hereinafter, embodiments for carrying out the present invention will be described. Note that software control (control by software) is actually executed by a hardware CPU (hereinafter also simply referred to as “hardware” or “CPU”) operating in accordance with the software. May be described as executing control.

  Here, the software is easier to code as follows. That is, rather than managing what is currently set and resetting only the change, it is easier to code the setting to the register every time even if it is useless. Also, coding is easier when there is no restriction on the setting timing. Currently, many of the reasons why settings are not in time for continuous jobs that require switching of the print mode are as follows. In other words, there are many registers that need to be set at a certain timing due to setting timing restrictions, such as the setting from the completion of the previous image formation to the completion of the next printing (paper interval). .

  Considering the above, the following embodiments have the following characteristics. That is, the setting value for each page is sequentially switched and stored in a plurality of buffers (temporary storage units) by hardware in the setting register, and the module using the setting register stores the setting values in the plurality of buffers for each page. Toggle in order and read and operate. The software sets the setting register in units of pages.

  For example, when the software sets the first page in the setting register, the setting value is stored (written) in the temporary storage unit M1 by hardware. When the software sets the second page in the setting register, the setting value is stored in the temporary storage unit M2 by hardware. Similarly, the temporary storage unit is toggled with M3, M4,. On the other hand, the hardware switches the temporary storage unit sequentially at the optimal timing and reads the set value.

  For this reason, the software does not have multiple setting registers that implement a single function, making register management easier, and simply setting the setting registers in units of pages without worrying about the setting timing for each register. Just do it. That is, it is not necessary to be restricted by the setting timing. Therefore, it is possible to prevent the setting by software (software load) from concentrating between sheets. As a result, the occurrence of machine downtime can be avoided.

Therefore, the above feature will be specifically described with reference to FIGS.
FIG. 1 is a schematic diagram illustrating an example of a mechanical configuration of an image forming apparatus according to an embodiment of the present invention.
The image forming apparatus 100 is an image forming apparatus such as a tandem digital color copying machine, a digital color multifunction peripheral, a color facsimile apparatus, and a color printer, and is configured as follows.

  That is, a plurality of light source (light emitting units) black (K), cyan (C), magenta (M), yellow (Y) semiconductor laser elements 200 (see FIGS. 2 and 3), polygons An optical device 102 that is an optical scanning device (writing device) including optical elements such as a mirror 102a is provided. In addition, a color image forming unit 112 including image forming process units 104, 106, 108, and 110 for K, C, M, and Y colors is also provided. Furthermore, a transfer unit 122 including an intermediate transfer belt 114 that is an endless transfer medium (endless moving member) is provided. That is, they constitute a color image forming unit (color image forming means).

  Each of the image forming process units 104, 106, 108, 110 of the color image forming unit 112 is a drum-shaped photoconductor that is an image carrier (write medium) indicated by a, 104, 106, 108, 110, respectively. 104a, 106a, 108a, 110a (hereinafter referred to as “photosensitive drum”). Further, developing devices 104c, 106c, 108c, 110c, and d, which are developing means indicated by adding charging units 104b, 106b, 108b, 110b, c, which are charging means indicated by b arranged around them, are provided. Also provided are primary transfer rollers 104d, 106d, 108d, 110d, etc., which constitute transfer means.

  The optical device 102 constitutes a post-object type optical device that does not use an fθ lens, and the laser beam L, which is a light beam emitted from each semiconductor laser element 200, once temporarily corresponds to the corresponding first cylindrical lens 202. (See FIG. 2). Then, the light is deflected to the corresponding reflecting mirror 102b by the polygon mirror 102a (other deflecting means such as a vibrating mirror may be used).

  In this embodiment, the laser beams L deflected by the polygon mirror 102a are reflected by the corresponding reflecting mirrors 102b because of the numbers corresponding to the respective colors K, C, M, and Y, and by the corresponding second cylindrical lenses 102c. It is condensed again. Thereafter, the surface to be scanned of the photosensitive drums 104a, 106a, 108a, 110a rotating in the sub-scanning direction of the image forming process units 104, 106, 108, 110 as a laser beam L used for exposure (hereinafter simply referred to as “scanning surface”). The surface is also repeatedly scanned in the main scanning direction by the polygon mirror 102a and exposed.

Since the irradiation of the laser beam L onto the surfaces of the photosensitive drums 104a, 106a, 108a, and 110a is performed using a plurality of optical elements as described above, timing synchronization is performed in the main scanning direction and the sub-scanning direction. .
The “main scanning direction” is defined as the scanning direction of the laser beam L, and the “sub-scanning direction” is a direction orthogonal to the main scanning direction. In this image forming apparatus 100, the photosensitive drums 104a, 106a, 108a, 110a. Is defined as the direction of rotation, that is, the direction of movement of their surfaces.

Each of the photosensitive drums 104a, 106a, 108a, and 110a includes a photoconductive layer including at least a charge generation layer and a charge transport layer on a conductive drum such as aluminum.
Each of the photoconductive layers is uniformly charged by being given surface charges by chargers 104b, 106b, 108b, and 110b each composed of a corotron, a scorotron, a charging roller, or the like. The surface of the charged photoconductive layer of each of the photosensitive drums 104a, 106a, 108a, and 110a is image-wise exposed by the laser beam L from the optical device 102, and a two-dimensional electrostatic latent image is formed. In this embodiment, the electrostatic latent image and the toner image described later are formed in the order of Y, M, C, and K.

  The electrostatic latent images formed on the surfaces of the photosensitive drums 104a, 106a, 108a, and 110a are respectively developed by the developing devices 104c, 106c, 108c, and 110c including a developing sleeve, a developer supply roller, and a regulating blade. Development is performed with toner, which is a developer of each color of K, C, M, and Y, and a toner image (developed image) of each color is formed. The toner images of the respective colors face the primary transfer rollers 104d, 106d, 108d, and 110d, which are transfer means to which the photosensitive drums 104a, 106a, 108a, and 110a are respectively applied with a transfer bias voltage across the intermediate transfer belt 114. Are transferred onto the intermediate transfer belt 114 moving in the direction indicated by the arrow A in the order of Y, M, C, and K.

The intermediate transfer belt 114 is stretched around the transport rollers 114a, 114b, and 114c, and one of the intermediate transfer belts 114 is rotated in the direction indicated by the arrow A by the transport rollers 114a or 114c, which are driving rollers, and Y, M, C, and K toner images are formed. In a state where a full-color toner image that has been superimposed and transferred is carried, the toner image is conveyed to the secondary transfer unit.
The secondary transfer unit includes a secondary transfer belt 118 that is transported in the direction indicated by the arrow B by transport rollers 118a and 118b. The conveyance roller 114b of the intermediate transfer belt 114 also functions as a secondary transfer counter roller.

  A sheet-like recording medium 124 such as high-quality paper or a plastic sheet is supplied to the secondary transfer unit from a recording medium storage unit 128 such as a paper feed cassette by a conveying roller 126. Then, a secondary transfer bias is applied to the conveyance roller 114 b that also functions as a secondary transfer counter roller, and the full-color toner image carried on the intermediate transfer belt 114 is held by suction on the secondary transfer belt 118. Transfer to the recording medium 124.

The recording medium 124 onto which the full-color toner image has been transferred is conveyed to the fixing device 120 by the rotation of the secondary transfer belt 118 in the arrow B direction.
The fixing device 120 is configured to include a fixing member 130 such as a fixing roller including silicone rubber or fluorine rubber, and pressurizes and heats the recording medium 124 together with the toner image to fix the toner image to the recording medium 124. After that, the printed matter 132 is discharged to the outside of the image forming apparatus 100.
After the toner image is transferred, the intermediate transfer belt 114 is prepared for the next image forming process after the transfer residual toner is removed by a cleaning unit 116 including a cleaning blade.

FIG. 2 is a perspective view showing a schematic configuration example of an optical system for exposing the photosensitive drum 104a in the optical device 102 of FIG.
The laser beam L emitted from the K-color semiconductor laser element 200 (200K) is collected by the first cylindrical lens 202 used for shaping the laser beam bundle, and passes through the reflection mirror 204 and the imaging lens 206. After that, it is deflected by the polygon mirror 102a.
The polygon mirror 102a is rotationally driven by a spindle motor (not shown) that rotates several thousand to several tens of thousands.

The laser beam L reflected by the polygon mirror 102a is reflected by the K-color reflection mirror 102b and then reshaped by the second cylindrical lens 102c, and the surface of the photosensitive drum 104a is moved in the main scanning direction by the polygon mirror 102a. Exposure is repeated scanning.
Further, in order to synchronize the scanning start timing (also referred to as “write timing”) of the laser beam L in the main scanning direction, a reflection mirror 208 is disposed.
The reflection mirror 208 emits the laser beam L to the photodiode other than the image forming area in the main scanning direction of the photosensitive drum 104a, for example, before starting scanning of the laser beam L in the main scanning direction (immediately before the main scanning image writing position). Are reflected toward the synchronization detection device (synchronization detection sensor) 210, and incident on the synchronization detection device 210 for detection.

When the synchronization detection device 210 (210K) detects the laser beam L, the synchronization detection device 210 (210K) serves as a reference for image writing control by the laser beam L in the main scanning direction in order to start main scanning of the laser beam L (main scanning image writing position). A synchronization detection signal is generated to synchronize processes such as a drive control signal generation process for the semiconductor laser element 200.
The semiconductor laser element 200 is driven by a pulse signal sent from a GAVD 310 (see FIG. 3) to be described later, and the laser beam L is exposed at a position corresponding to a predetermined image bit of image data (image information) as will be described later. Then, an electrostatic latent image is formed on the photosensitive drum 104a (image information is written by the laser beam L).
In addition, each part (except for the polygon mirror 102a) including the semiconductor laser element 200 and the synchronization detection device 210 described above is actually mounted for each color.

FIG. 3 is a block diagram illustrating a schematic configuration example of the control unit of the image forming apparatus 100 illustrated in FIG. 1.
This control unit is configured as a scanner unit 302, a printer unit 308, and a main control unit 330.
The scanner unit 302 reads an image of a document by performing a scanning process using an optical system including a solid-state imaging device such as a CCD color image sensor or a CMOS color image sensor. The scanner unit 302 includes a VPU (Video Processing Unit) 304 and an IPU (Image Processing Unit) 306.

The VPU 304 performs A / D conversion on the analog image signal output from the solid-state image sensor to acquire image data that is a digital image signal, and performs black offset correction, shading correction, and pixel position correction on the image data.
The IPU 306 performs image processing for digitally converting the image data from the VPU 304 as image data in the RGB color system to the CMYK color system. Note that “R” indicates red, “G” indicates green, and “B” indicates blue.

  The scanner unit 302 is communicably connected to the GAVD 310 via an image data interface (image data IF) 318. Therefore, when the image transfer request signal MFSYNC_N (see FIG. 4) for each color is received from the GAVD 310 via the image data interface 318, the scan process can be started by the IPU 306. Further, the image data of each color subjected to image processing by the IPU 306 can be transmitted to the printer unit 308 via the image data interface 318.

  The printer unit 308 includes a GAVD (Gate Array Video Driver) 310 corresponding to a writing control device, an LD driver 312 (312K, 312C, 312M, 312Y) for each color, and an optical scanning device 102. . The optical scanning device 102 includes a semiconductor laser element 200 (200K, 200C, 200M, 200Y) for each color and a synchronization detection device 210 (210K, 210C, 210M, 210Y).

  When the GAVD 310 transmits an image transfer request signal MFSYNC_N for each color to the scanner unit 302 and receives image data for each color from the scanner unit 302, the GAVD 310 performs processing based on the image data for each color. That is, a drive control signal for performing drive control of each semiconductor laser element 200 via each LD driver 312 is generated. Therefore, the GAVD 310 functions as a control unit that performs drive control of each semiconductor laser element 200.

Each LD driver 312 is mounted for each color of KCMY, and supplies a current for driving the corresponding semiconductor laser element 200 to the semiconductor laser element 200 by a drive control signal from the GAVD 310.
Each semiconductor laser element 200 is mounted for each color of KCMY and is two-dimensionally arranged.
The scanner unit 302 and the printer unit 308 are connected to the main control unit 330 via the system bus 316, and image reading and image formation are controlled by commands from the main control unit 330.

The main control unit 330 includes a central processing unit (hereinafter referred to as “CPU”) 320 and a RAM 322 that provides a processing space used by the CPU 320 for processing.
The CPU 320 can be any CPU known so far, for example, CISC (Complex Instruction Set Computer) such as PENTIUM (registered trademark) series or compatible CPU, RISC (Reduced Instruction Set Computer) such as MIPS, etc. Can be used.

The CPU 320 expands the program stored in the ROM 324 in the RAM 322 at startup. Thereafter, an instruction from the user (actually an operation unit not shown or an external device such as a personal computer not shown) is received from the RAM 322 via the interface 328, and a program for executing processing corresponding to the instruction is called from the RAM 322. , Copy, facsimile, scanner, image storage, etc. are executed.
Further, the main control unit 330 includes a ROM 324, and stores initial setting data, control data, programs, and the like of the CPU 320 so that the CPU 320 can use them.

The image storage 326 is configured as a fixed or detachable memory device such as a hard disk device, an SD card, or a USB memory, stores image data acquired by the image forming apparatus 100, and can be used for various processes by the user. Yes.
The I / O control unit 329 drives various motors including a main motor that rotates the photosensitive drums 104a, 106a, 108a, and 110a, the intermediate transfer belt 114, and the like, a spindle motor that rotates the polygon mirror 102a, and sensors. Detection is performed.
Further, the color misregistration correction regarding the error deviation of the sub-scanning direction magnification (sub-scanning magnification) and the sub-scanning direction magnification (sub-scanning magnification) is performed by the I / O control unit 329 based on the correction amount. 106a, 108a, 110a and the motor speed of the conveying roller 114a are adjusted. In this embodiment, the conveyance roller 114 a functions as a driving roller for the intermediate transfer belt 114.

In the image forming apparatus 100 configured as described above, when the printer unit 308 is driven based on the image data from the scanner unit 302 to form an electrostatic latent image on the photosensitive drum 104a and the like and the image is output, the CPU 320 Performs position control in the main scanning direction and the sub-scanning direction of a recording medium such as high-quality paper and plastic film.
The CPU 320 outputs a start signal to the GAVD 310 when starting scanning in the sub-scanning direction on the document.

When the GAVD 310 receives the start signal from the CPU 320, the image transfer request signal MFSYNC_N for each color is output to the IPU 306 in the scanner unit 302 via the image data interface 318, so that the IPU 306 starts scanning processing.
After that, when the GAVD 310 receives image data of each color from the IPU 306, it stores them in a memory 340 (see FIG. 4) described later, processes the received image data of each color, and generates a drive control signal. Output to the driver 312.

When each LD driver 312 receives a drive control signal from the GAVD 310, it generates a current for driving the corresponding semiconductor laser element 200.
Thereafter, each LD driver 312 supplies the generated current to the corresponding semiconductor laser element 200, thereby turning on the semiconductor laser element 200.
Each LD driver 312 drives the corresponding semiconductor laser element 200 using pulse width modulation (PWM) control or power modulation (PM) control.

FIG. 4 is a block diagram illustrating a configuration example of the GAVD 310 of FIG. For convenience of illustration, the LD driver 312 (312K, 312C, 312M, 312Y) is included in the GAVD 310, but may be included.
As shown in FIG. 4, the GAVD 310 includes a register 300, a register buffer control unit (hereinafter also simply referred to as “buffer control unit”) 300a, and write control units 350 (350K, 350C, 350M, and 350Y). .

A start signal is output from the CPU 320, and the printing operation starts. The start signal is input to the K color write control unit 350K as the reference color. Then, the write control unit 350K sends an operation start signal (print start signal) STOUT_N to the other color (C, M, Y) write control units 350C, 341K by the K-color delay line control unit 341K at a specific line-managed timing. Output to 350M, 350Y.
The delay line control unit 341K functions as a signal processing unit, controls the number of delay lines in the sub-scanning direction (number of sub-scanning delay lines) based on the operation start signal STOUT_N to be output, and outputs K-color image data. The request signal MFSYCNC_N is output to the previous stage IPU 306.

The delay line controllers 341C, 341M, and 341Y of the other write controllers 350C, 350M, and 350Y control the number of sub-scan delay lines based on the input operation start signal STOUT_N, respectively. M, Y) image data request signal MFSYCNC_N is output to the previous IPU 306.
Each delay line control unit 341 determines the output timing of the image data request signal MFSYCNC_N for each color from the positional relationship between the photosensitive drums 104a, 106a, 108a, and 110a.

  In the image forming apparatus 100 of this embodiment, as described with reference to FIG. 1, toner images are formed in the order of Y, M, C, and K. Therefore, the output timing of the image data request signal MFSYCNC_N is as follows. For example, the time difference between the output of the Y-color and M-color image data request signal MFSYCNC_N corresponds to the time required for the belt movement between the photosensitive drums 110a and 108a. Therefore, when the time required for the belt movement elapses after the Y delay line control unit 341 outputs the Y image data request signal MFSYCNC_N, the M delay line control unit 341 performs the M color image data. The request signal MFSYCNC_N is output.

The IPU 306 outputs the image data for each color from the scanner unit 302 to the GAVD 310 at a certain timing managed from the corresponding color image data request signal MFSYNCNC_N.
In the GAVD 310, the image data for each color input from the IPU 306 is stored in the corresponding memory 340 (340K, 340C, 340M, 340Y) and expanded two-dimensionally (bitmap), and the corresponding image processing unit 342 Various image processing is performed at (342K, 342C, 342M, 342Y) and output to the corresponding output data control unit 344 (344K, 344C, 344M, 344Y).

Each output data control unit 344 (344K, 344C, 344M, 344Y) converts the image data processed by the corresponding image processing unit 342 (342K, 342C, 342M, 342Y) into a drive pulse-like drive control signal. Each drive control signal is transmitted to the corresponding LD driver 312 (312K, 312C, 312M, 312Y), and drives the corresponding semiconductor laser element 200 (200K, 200C, 200M, 200Y).
Note that the GAVD 310 controls the writing timing of the laser beam L for each color in the main scanning direction based on the synchronization detection signal from the synchronization detection device 210 (210K, 210C, 210M, 210Y) for each color.

  Various register settings for each color (K, C, M, Y) to the GAVD 310 are performed by communication from the CPU 320 through connection (bus connection) between the GAVD 310 and the CPU 320 via the system bus 316. Register values (hereinafter also referred to as “set values” or “data”) for each color (K, C, M, Y) stored and set in the register 300 by the CPU 320 are stored in the temporary storage unit of the buffer control unit 300a. Then, the data in the temporary storage unit is switched and read at a predetermined timing. Each control circuit constituting each part in each write control unit 350 (350K, 350C, 350M, 350Y) operates according to the setting register value.

  Here, the predetermined timing corresponds to a timing at which the operation is completed for each of the control circuits. For example, there is a negated edge timing corresponding to the image end position of the sub-scanning gate signal PFGATE indicating the effective image area. For example, each image processing unit 342 in FIG. 4 completes (completes) the operation of the corresponding control circuit once at the end of the corresponding effective image area (the negation edge timing of the sub-scanning gate signal PFGATE). Therefore, the switching of the temporary storage unit when reading the corresponding register value is performed at the timing when the operation of the corresponding control circuit in each image processing unit 342 is completed.

FIG. 5 is a block diagram illustrating a configuration example of the register 300 and the buffer control unit 300a in FIG.
The register 300 is a storage unit that stores various setting values necessary for writing control of image data (image information).

The buffer control unit 300a is a control unit, and includes write selectors 501 and 502, temporary storage units (buffers) 503 and 504, and read selectors 505 and 506, as shown in FIG. Control such as reading of (setting value) is performed. Note that each address area of the temporary storage units 503 and 504 corresponds to primary storage means.
The control of the buffer control unit 300a will be described by taking each data in the addresses “0002 [hex]” and “02FC [hex]” of the register 300 as an example.

When the CPU 320 writes the first page data (a set value of various setting values necessary for image formation on the first page) to the address “0002 [hex]” of the register 300, the write selector 501 stores the data. Is stored at the address “0” of the temporary storage unit 503.
Similarly, when data of the first page (different from that stored in address “0002 [hex]”) is written in “address 02FC [hex]”, write selector 502 stores the data in temporary storage unit 504. Store at address “0”.

  Then, the CPU 320 writes the data “0001 [hex]” to the address “0005 [hex]” to complete the setting of the first page, and the data “0001 [hex]” serves as a page switching signal indicating page switching. Input to the write selectors 501 and 502. Therefore, both the write selectors 501 and 502 can write the data of the second page to the next address “1”.

  Next, when the data of the second page is written to the addresses “0002 [hex]” and “02FC [hex]” by the CPU 320, the write selectors 501 and 502 write the data to the addresses of the temporary storage units 503 and 504, respectively. Store in “1”. Thereafter, by the same processing, the data of the third page is stored in the address “2” of the temporary storage units 503 and 504, the fourth page is stored in the address “3”,..., And the sixth page is stored in the address “5”. Next, each data of the seventh page is stored in the address “0”.

  Reading data from the temporary storage units 503 and 504 operates independently of writing, and the first page reads data (register values A and B) at the address “0” of the temporary storage units 503 and 504, respectively. Selectors 505 and 506 select, read and output. Then, switching to reading of data from other addresses of the temporary storage units 503 and 504 is performed by a sub-scanning gate signal PFGATE as a read switching signal.

  Also, for example, the address “0002 [hex]” of the register 300 can be switched at the image formation end position by switching by the negation of the sub-scanning gate signal PFGATE. The address “02FC [hex]” of the register 300 can be switched at the image formation start position by switching by the assertion of the sub-scanning gate signal PFGATE.

In this embodiment, the page switching (update) at the time of register setting is performed by setting “0001 [hex]” to the address “0005 [hex]” as described above. As soon as each register set value is stored in the primary storage units 503 and 504, the page may be switched (the address of the primary storage units 503 and 504 is incremented).
Further, the buffer control unit 300a shown in FIG. 5 has a circuit configuration in which two types of register values are accumulated and read out at addresses “0” to “5” of two primary storage units. A configuration in which the number of types and the number of accumulation (the number of addresses in the primary storage unit) are changed may be used. However, the number of addresses in the primary storage unit (corresponding to the number of primary storage means) is “2” or more.

  In this embodiment, each page that can be output by the delay line control unit 341K of the write control unit 350K in FIG. 4 after the start of continuous printing of a plurality of pages until image formation (image formation) of the first page is completed. In order to increase the number of register values for each page type that can be stored from the maximum number of operation start signals (in this example, “5”), the number of addresses in the temporary storage units 503 and 504 is set to five.

FIG. 6 is a timing chart showing an example of the relationship among the addresses of the temporary storage units 503 and 504 in FIG. 5, the register setting timing of each page, the operation start signal STOUT_N, and the sub-scanning gate signal PFGATE for each color.
In this example, the writing control unit 350K outputs the operation start signal STOUT_N five times before the sub-scanning gate signal PFGATE (K) that completes the printing of the K color whose image formation timing is the latest is negated. Then, 6 pages of registers are set during image formation for the first page of K color. In this case, since it is necessary to hold the register setting values for six pages, the number of addresses in the temporary storage units 503 and 504 is six in the example of FIG.

Here, for convenience of understanding, an operation example in the continuous printing operation in the GAVD 310 shown in FIG. 4 will be described with reference to FIGS. 7 and 10 in comparison with the conventional operation. It should be noted that FIG. 4 is also used to describe the conventional operation. However, the buffer control unit 300a does not exist in the conventional GAVD.
FIG. 7 is a timing chart showing an operation example in the continuous printing operation in the GAVD 310 shown in FIG.

FIG. 10 is a timing chart showing an operation example in the continuous printing operation in the conventional GAVD.
In the conventional GAVD, as shown in FIG. 10, since the print settings are different between the second page and the third page, the setting completion timing (soft timing) to the register 300 by the CPU 320 is not in time, and the down time of the Td time is reduced. It has occurred.

That is, the output of the operation start signal STOUT_N for the third page is delayed by the Td time, and it takes Xd time until the sub-scan gate signal PFGATE for each color is asserted, resulting in a decrease in printing throughput.
The main causes of downtime are as shown below, for example. There is much data (register value) that needs to be set in the register 300 between the sheets. Various image forming adjustment operations are performed between sheets, and various statuses and sensor outputs are monitored by polling or the like for machine state management, thereby increasing the load on the CPU 320.

  In contrast to the conventional GAVD, in this embodiment, the buffer control unit 300a shown in FIG. 5 is provided in the GAVD 310, and the number of addresses in the temporary storage units 503 and 504 is six, so printing is performed on the second and third pages. Even if the settings are different, the conventional problem does not occur. In other words, the timing for completing the setting to the register 300 by the CPU 320 is not in time, and no downtime occurs. In the example of FIG. 7, the setting of each color in the register 300 for each page is completed before the operation start signal STOUT_N is output. That is, the settings in the register 300 are not concentrated between the paper sheets, and the CPU 320 performs the setting in the register 300 at a timing when the load of the CPU 320 is small, so that downtime can be prevented.

FIG. 8 is a timing chart showing another operation example during the continuous printing operation in the GAVD 310 shown in FIG.
In the example of FIG. 7, it is necessary to perform register setting for one page before outputting the operation start signal STOUT_N by the write control unit 350K of FIG.

Therefore, by setting the register setting timing before the output of the image data request signal MFSYNCC_N for each color, the write control unit 350K can output the operation start signal STOUT_N before the completion of all color settings, thereby shortening the first print time. can do.
Note that there is a problem register on the reading side unless the setting is completed before the operation start signal STOUT_N is output. Although this register needs to have the timing shown in FIG. 7, since there are not many such registers, the first print time can be sufficiently shortened by using the register shown in FIG.

FIG. 9 is a timing chart illustrating an example of register value reading switching timing by the buffer control unit 300a of FIG.
In this example, the number of write selectors, temporary storage units, and read selectors provided in the buffer control unit 300a is four, unlike the one shown in FIG. Also, the following three signals are used as read switching signals used for switching the reading of the register values A, B, C, and D from the respective read selectors.

For example, the register value D is the image data request signal MFSYCNC_N, and the register value C is the operation start signal STOUT_N, and the address on the reading side of the corresponding temporary storage unit is switched to switch the register setting data. Similarly, the register value A and the register value B are switched at the negate edge and the assert edge of the sub scanning gate signal PFGATE.
Although only the sub-scanning gate signal PFGATE is shown as the read switching signal of the buffer control unit 300a shown in FIG. 5, the switching signal is changed according to the register value to change the switching timing for each register value as shown in FIG. Any of STOUT_N, image data request signal MFSYCNC_N, and sub-scanning gate signal PFGATE is used.

Each delay line control unit 341 completes (completes) the operation of the corresponding control circuit once the corresponding image data request signal MFSYCNC_N is output. Therefore, the switching of the temporary storage unit when reading the corresponding register value can be performed at the timing when the operation of the corresponding control circuit in each delay line control unit 341 is completed.
In the delay line control unit 341K, the operation of the corresponding control circuit is completed once when the operation start signal STOUT_N is output. Therefore, the switching of the temporary storage unit when reading the corresponding register value can be performed at the timing when the operation of the corresponding control circuit in the delay line control unit 341K is completed.

  As described above, in this embodiment, the buffer control unit 300a determines that the setting value of the first page stored in the register 300 (storage unit) is the addresses “0” to “N (N ≧ N ≧) of the temporary storage units 503 and 504. 2) ”is written to a predetermined address“ 0 ”. As the setting values for the Nth page (after the second page) stored in the register 300, the setting values up to the (N-1) th page among the addresses “0” to “N” of the temporary storage units 503 and 504 are written. Write to an address different from the specified address. The setting value of the (N + 1) th page stored in the register 300 is written to the address “0” where the setting value of the first page is written. The setting values written in the addresses “0” to “N” in the temporary storage units 503 and 504 are read out by switching the addresses in the order of writing. As a result, control such as timing management for the register 300 on the software side is not complicated (that is, the burden on the software is reduced), and machine downtime can be eliminated.

  In addition, address switching (selection) when writing a setting value to any one of the addresses “0” to “N” of the temporary storage units 503 and 504 and the addresses “0” to “N” of the temporary storage units 503 and 504 are performed. The addresses are switched (selected) independently of each other when the set value is read from any one of “N”. As a result, it is possible to reliably write and read setting values to and from the addresses “0” to “N” in the temporary storage units 503 and 504 at appropriate timings, and the software load is further reduced by that amount.

Further, switching of addresses (temporary storage means) when reading set values is performed at a predetermined timing (for example, when the operation is completed for each corresponding control circuit at the end or start of image formation for each page). Thus, the above switching can be performed reliably without affecting the image formation of each page.
Furthermore, the number of addresses in the temporary storage units 503 and 504 (the number of temporary storage units) is the delay line control unit 341K between the start of continuous image formation of a plurality of pages and the completion of image formation of the first page. Is the number of addresses at which the number of setting values of each page that can be stored in the temporary storage units 503 and 504 is larger than the maximum number of operation start signals (image formation start signals) of each page that can be output. This ensures that machine downtime is eliminated.

As described above, the present invention is applied to an indirect transfer type image forming apparatus in which the toner images of the respective colors are sequentially transferred from the respective photoreceptors onto the intermediate transfer belt and then transferred to the recording medium. Although the embodiment has been described, the present invention is not limited to this. That is, the present invention can be applied not only to a direct transfer type image forming apparatus that directly transfers a toner image of each color from each photoconductor to a recording medium, but also to other types of image forming apparatuses. Alternatively, the present invention can also be applied to a monochromatic image forming apparatus such as monochrome, or an image forming apparatus having two or three colors.
Further, the present invention is not limited to the above-described embodiment, and it goes without saying that all the technical matters included in the technical idea described in the claims are covered.

DESCRIPTION OF SYMBOLS 100: Image forming apparatus 102: Optical apparatus 102a: Polygon mirror 102b, 204, 208: Reflection mirror 102c: 2nd cylindrical lens 104,106,108,110: Image formation process part 104a, 106a, 108a, 110a: Photosensitive drum 104b, 106b, 108b, 110b: chargers 104c, 106c, 108c, 110c: developing unit 112: color image forming unit 114: intermediate transfer belt 114a, 114b, 114c: transport roller 118: secondary transfer belt 120: fixing device 122 : Transfer unit 124: Recording medium 130: Fixing member 132: Printed product 200 (200K, 200C, 200M, 200Y): Semiconductor laser element 202: First cylindrical lens 206: Imaging lens 210 (210K, 210C, 210M, 210) Y): Synchronization detection device 300: Register 300a: Register buffer control unit 302: Scanner unit 304: VPU
306: IPU 308: Printer unit 310: GAVD
312 (312K, 312C, 312M, 312Y): LD driver 320: CPU 322: RAM 324: ROM 326: Image storage 328: Interface 329: I / O control unit 330: Main control unit 340 (340K, 340C, 340M, 340Y) ): Memory 341 (341K, 341C, 341M, 341Y): Delay line control unit 342 (342K, 342C, 342M, 342Y): Image processing unit 344 (344K, 344C, 344M, 344Y): Output data control unit 501, 502 : Write selector 503, 504: Temporary storage units 505, 506: Read selector

JP 2006-259360 A

Claims (7)

A writing control device for controlling a writing device for writing image information on a writing medium,
Storage means for storing various setting values necessary for the writing control of the image information;
N (N ≧ 2) temporary storage means, and the setting value of the first page stored in the storage means is written in a predetermined temporary storage means among the N temporary storage means, The setting value of the Nth page stored in the storage means is written in a temporary storage means different from the temporary storage means in which the setting values up to the (N-1) th page among the N temporary storage means are written, and the storage means The setting value of the (N + 1) th page stored in is written in the same temporary storage means as the temporary storage means in which the setting value of the first page is written, and the setting values written in the N temporary storage means are read out: And a control means for switching the temporary storage means in the order of writing.   The control means switches the temporary storage means when writing a setting value to any of the N temporary storage means, and the temporary storage means when reading the setting value from any of the N temporary storage means. 2. The writing control apparatus according to claim 1, wherein switching is performed independently of each other.   The writing control apparatus according to claim 1, wherein the control unit performs switching of the temporary storage unit when reading the set value at a predetermined timing.   The write control device according to any one of claims 1 to 3, a writing device that writes image information on a write target medium under the control of the write control device, and the image information that is written by the writing device. An image forming apparatus comprising: a writing medium to be written; and the writing control device controlling the writing device to write the image information on the writing medium. 4. The writing control apparatus according to claim 3, a writing apparatus that writes image information on a writing medium under the control of the writing control apparatus, and a writing medium on which the image information is written by the writing apparatus. An image forming apparatus in which the writing control device controls the writing device to write the image information on the medium to be written.
The control means of the writing control device switches the temporary storage means when reading the set value at the end of image formation including writing of image information by the writing device for each page. Item 5. The image forming apparatus according to Item 4. 4. The writing control apparatus according to claim 3, a writing apparatus that writes image information on a writing medium under the control of the writing control apparatus, and a writing medium on which the image information is written by the writing apparatus. An image forming apparatus that causes the write control device to control the write control device to write the image information on the medium to be written,
The control unit of the writing control device switches the temporary storage unit when reading the setting value at the start of image formation including writing of image information by the writing device of each page. Item 5. The image forming apparatus according to Item 4. The image forming apparatus according to any one of claims 4 to 6,
Comprising signal processing means for outputting an image formation start signal;
The N, which is the necessary number of the temporary storage means, can be used for image formation of each page that can be output by the signal processing means from the start of continuous image formation of a plurality of pages to the completion of image formation of the first page. An image forming apparatus, wherein the number of set values of each page that can be temporarily stored is larger than the maximum number of start signals.

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