JP2014177106A - Image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time up to completion of a startup of a system by preventing control data which is not necessary for light quantity control over a light source from being set again in an image formation apparatus that sets control data, characteristic of a light beam scanner, stored in a nonvolatile memory of the light beam scanner and including light quantity control data in a register and uses the control data for illumination control over the light source.SOLUTION: A non-reboot area and a reboot area are set in a nonvolatile memory 109, control data needed only when a power source is turned on and when a unit is replaced, for example, an adjustment value for a write unit, an LD current value for a process, etc., are stored in the non-reboot area, and light quantity control data is stored in the reboot area. When the power source is turned on, a light source control part 104 reads the control data out of the non-reboot area and reboot area, and sets the control data of the reboot area in internal registers. When the internal registers are cleared as a door is opened and closed, the light quantity control data is read out of the reboot area and set again in the internal registers.

Description

  The present invention relates to an electrophotographic image forming apparatus provided with a light beam scanning device.

  In an electrophotographic image forming apparatus equipped with a light beam scanning device, a laser diode (hereinafter referred to as LD), which is a light beam light source, is turned on based on image data to expose a photoconductor to form an electrostatic latent image. The electrostatic latent image is developed to form a toner image, and the toner image is transferred to a recording material such as paper to form an image on the recording material.

  As such an image forming apparatus, control data unique to the light beam scanning device such as a beam position correction value, a magnification correction value, and a beam power correction value is stored in advance in a nonvolatile memory provided in the light beam scanning device. In some cases, a printer control unit (main body control unit) of an image forming apparatus reads control data and uses it for LD lighting control when the power is turned on or when an image is formed (Patent Document 1).

  However, in the image forming apparatus described in Patent Document 1, since the printer control unit reads a large amount of control data, the time required for reading (hereinafter referred to as reading time) becomes long, and the load on the CPU in the printer control unit is large. There is a problem.

  On the other hand, as a technique for reducing the load on the CPU, control data such as shading correction information and pixel defect information stored in the non-volatile memory is automatically transmitted by a hardware configuration memory read control circuit when the power is turned on. It is known to read (hardware) and set in a register (Patent Document 2). Therefore, if this technique is applied to the image forming apparatus described above, it is considered that the reading time can be shortened and the load on the CPU can be reduced.

  However, in the above-described image forming apparatus, the following problems cannot be solved only by changing the control data reading and register setting means from a CPU that performs software control to a memory read control circuit having a hardware configuration. .

  Among the control data stored in the non-volatile memory in the light beam scanning device, each color used only when the power is turned on, in addition to the light amount control data used every time the LD is turned on, such as the light amount gain adjustment value The write unit adjustment value for correcting the write position deviation and the LD current value for the assembly process used only when the write unit is replaced are stored.

  In some cases, the light amount control data needs to be reset even after the control data is set in the register in the image forming apparatus when the power is turned on. That is, when the light beam scanning device is turned off to turn off the LD by opening the front door, the reset button is pressed to reset the light amount control data in the register in the light beam scanning device. At this time, it is necessary to change the light amount control data to be referred to by changing the printing conditions (color / monochrome, etc.).

  Even in such a case, if the control data stored in the non-volatile memory is reset in the register in the same manner as when the power is turned on, it takes time to reset the control data unnecessary for the light amount control. There is a problem that it takes a long time to complete the system startup.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a light beam scanning device and to store the light amount control data stored in the nonvolatile memory. In the image forming apparatus used for controlling the lighting of the light source of the light beam scanning device, the control data unnecessary for the light amount control of the light source is prevented from being reset, and the system startup is completed. It is to shorten the time until.

  The present invention includes a light beam scanning device, sets control data specific to the light beam scanning device including light amount control data stored in a nonvolatile memory in a register, and turns on a light source of the light beam scanning device An image forming apparatus used for control, wherein when the power of the image forming apparatus is turned on, a boot unit that reads the control data stored in the nonvolatile memory and sets the control data in the register, and the image forming Reboot means for reading out the light amount control data from the nonvolatile memory and setting it in the register when a situation that requires resetting of the light amount control data set in the register occurs in a state where the power of the device is on, An image forming apparatus having

  According to the present invention, the control data unique to the light beam scanning device including the light amount control data, which is provided in the nonvolatile memory and includes the light beam scanning device, is set in the register, and the light source of the light beam scanning device is set. In the image forming apparatus used for the lighting control of the light source, it is possible to prevent resetting of control data unnecessary for the light amount control of the light source, and to shorten the time until the start-up of the system is completed.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. It is a figure for demonstrating the structure of the control system of the light beam scanning apparatus in FIG. It is a figure which shows an example of the internal structure of the light source control part in FIG. 2, and a non-volatile memory. 5 is a flowchart illustrating operations when the power is turned on and when energy saving is restored in the image forming apparatus according to the embodiment of the present invention. 5 is a flowchart showing recovery processing in the image forming apparatus according to the embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings.
<Configuration of image forming apparatus>
FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention.

  This image forming apparatus has a configuration in which image forming portions of respective colors are arranged along an intermediate transfer belt, and is called a so-called tandem type. That is, a plurality of image forming units (electrophotographic process units) 6Y, 6M, 6C, and 6BK are arranged along the intermediate transfer belt 25 in order from the upstream side in the rotational movement direction of the intermediate transfer belt 25.

  The plurality of image forming units 6Y, 6M, 6C, and 6BK have the same internal configuration except that the colors of the toner images to be formed are different. The image forming unit 6Y forms a yellow toner image, the image forming unit 6M forms a magenta toner image, the image forming unit 6C forms a cyan toner image, and the image forming unit 6BK forms a black toner image. Therefore, in the following description, the image forming unit 6Y will be specifically described, and the other components of the image forming units 6M, 6C, and 6BK are replaced with Y attached to the respective components of the image forming apparatus 6Y. , M, C, and BK are only displayed in the figure, and the description is omitted.

  The intermediate transfer belt 25 is an endless belt wound around a drive roller 7 and a driven roller 8 that are driven to rotate. The drive roller 7 is rotationally driven by a drive motor (not shown), and the drive motor, the drive roller 7, and the driven roller 8 function as drive means for moving the intermediate transfer belt 25.

  The image forming unit 6Y includes a photoconductor drum 9Y, a charger 10Y disposed around the photoconductor drum 9Y, a light beam scanning device 11, a developing device 12Y, a photoconductor cleaner (not shown), a static eliminator 13Y, and the like. It is configured. The light beam scanning device 11 is configured to irradiate laser beams 14Y, 14M, 14C, and 14BK that are exposure lights corresponding to the colors of the toner images formed by the image forming units 6Y, 6M, 6C, and 6BK. .

  In the image formation, the outer peripheral surface of the photosensitive drum 9Y is uniformly charged by the charger 10Y in the dark, and then exposed by the laser beam 14Y corresponding to the yellow image from the light beam scanning device 11, thereby electrostatic latent An image is formed. The developing device 12Y visualizes (develops) the electrostatic latent image with yellow toner, thereby forming a yellow toner image on the photosensitive drum 9Y.

  This toner image is transferred onto the intermediate transfer belt 25 by the action of the transfer unit 15Y at a position (primary transfer position) where the photosensitive drum 9Y and the intermediate transfer belt 25 are in contact with each other.

  After the transfer of the toner image is completed, unnecessary toner remaining on the outer peripheral surface of the photosensitive drum 9Y is wiped off by the photosensitive cleaner, and then is neutralized by the static eliminator 13Y and waits for the next image formation.

  The portion of the intermediate transfer belt 25 to which the yellow toner image has been transferred moves to the next image forming unit 6M. In the image forming unit 6M, a magenta toner image is formed on the photoreceptor drum 9M by a process similar to the image forming process in the image forming unit 6Y, and the toner image is formed on the intermediate transfer belt 25 as a yellow image. Is transferred in a superimposed manner.

  The portion of the intermediate transfer belt 25 to which the yellow toner image and the magenta toner image have been transferred is further moved sequentially to the image forming units 6C and 6BK, and cyan toner formed on the photosensitive drum 9C by the same operation. The image and the black toner image formed on the photoconductive drum 9BK are superimposed and transferred. Thus, a full color image is formed on the intermediate transfer belt 25. Here, the images are formed in the order of yellow, magenta, cyan, and black, but the order of creation is not limited to this.

  On the other hand, the sheets 4 stored in the sheet feeding tray 1 are sent out in order from the top, conveyed onto the intermediate transfer belt 25, and at a position where the intermediate transfer belt 25 and the sheet 4 are in contact (secondary transfer position). A full-color toner image is transferred. The sheet 4 on which the full-color toner image is formed is peeled off from the intermediate transfer belt 25 and the image is fixed by the fixing device 16, and then discharged to the outside of the image forming apparatus.

<Control system of light beam scanning device>
FIG. 2 is a diagram for explaining the configuration of the control system of the light beam scanning apparatus 11 in FIG.

  The control system of the light beam scanning device 11 includes an image processing unit 102, an image data output unit 103, a light source control unit 104, a synchronization detection detection unit 108, and a nonvolatile memory 109. The image data output unit 103 includes a data selection unit 103a and an image output control unit 103b.

  A printer control unit (main body control unit) 101 controls the entire image forming apparatus. The printer control unit 101 also knows the state of various sensors and operation panel of the image forming apparatus such as a door open / close sensor of the image forming apparatus (not shown) and a reset button. In the printer control unit 101, the built-in CPU can perform data transmission by serial communication with the nonvolatile memory 109, the image data output unit 103, and the light source control unit 104.

  The image processing unit 102 sends four-color image data of black, cyan, yellow, and magenta to the data selection unit 103a. In the data selection unit 103a, the data signal of each color is output based on the LD lighting signal from the image output control unit 103b in accordance with the image forming order.

  The light source control unit 104 controls the light beam emitted from the light source 105 to the polygon mirror 106 based on the data signal and the LD lighting control signal sent from the data selection unit 103a and the image output control unit 103b, respectively. A modulation signal is output to the light source 105, and the light source 105 emits each light beam based on the modulation signal.

  As the light source 105, not only a semiconductor laser having a single light emitting point with a single light source element, but also a semiconductor laser diode array having a plurality of light emitting points, or a surface emitting semiconductor laser having light emitting points arranged two-dimensionally is used. You can also.

  The light beam emitted from the light source 105 enters the mirror surface of the polygon mirror 106. The light beam is deflected in the main scanning direction by the rotation of the polygon mirror 106, and scans each of the photosensitive drums 9BK, 9C, 9M, and 9C (hereinafter referred to as the photosensitive drum 9) via a scanning lens and a mirror (not shown). By exposing the photosensitive drum 9, a desired electrostatic latent image is formed.

  A synchronization detector 107 having a light receiving element is disposed at the scanning tip position of the light beam scanned by the rotation of the polygon mirror 106, and the rotation position of the polygon mirror 106 indicates the synchronization position indicating the writing position of the main scanning of the light beam. Detect as detection signal.

  The nonvolatile memory 109 stores various control data unique to the light beam scanning device 11 (details will be described later with reference to FIG. 3). When the power of the image forming apparatus is turned on, the light source control unit 104 reads control data. The light amount control data in the read control data is set in an internal register and used for light amount control of the light source 105.

  Further, the light source control unit 104 transfers control data other than the light amount control data in the read control data to the printer control unit 101. The printer control unit 101 sets the transferred control data in an internal register and uses it for adjusting the image data output timing in the image data output unit 103.

<Internal configuration of light source control unit and nonvolatile memory>
FIG. 3 is a diagram illustrating an example of the internal configuration of the light source control unit 104 and the nonvolatile memory 109 in FIG.

  As illustrated, the light source control unit 104 includes a read command register 121, a memory read control unit 122, a light amount control data register 123, a control data register write control unit 124, and a control data transfer unit 125, each of which has a hardware configuration. I have. The printer control unit 101 sets a boot command (details will be described later) in the read command register 121 by serial communication.

  The read instruction register 121 as a boot / reboot output means includes a boot instruction register 121a and a reboot instruction register 121b. In the boot command register 121a, “1” is set by the printer control unit 101 when the power of the image forming apparatus is turned on. In the reboot command register 121b, when a situation occurs that requires resetting of the light amount control data set in the light amount control data register 123 while the image forming apparatus is powered on (hereinafter, at reboot), the printer control unit 101 sets “1”. Here, when rebooting, the front door of the image forming apparatus is opened / closed (opened and closed), the reset button is pressed, the print settings (color / monochrome, etc.) are changed, etc. is there. Since the boot instruction register 121 a and the reboot instruction register 121 b are connected to the memory read control unit 122, the set values of these registers are output (transmitted) to the memory read control unit 122.

  The nonvolatile memory 109 includes a non-reboot area 111 and a reboot area 112 as storage areas for control data unique to the light beam scanning device 11. The non-reboot area 111 stores a process adjustment LD current value, a color misregistration correction value, a magnification correction value, a beam pitch adjustment value, and a magnification error deviation value as data other than the light amount control data. In the reboot area 112, a shading correction value and a light amount gain adjustment value are stored as light amount control data. Here, each of the non-reboot area 111 and the reboot area 112 is preferably an area where addresses are continuous. For example, the type of data (control data other than light quantity control data / light quantity control data) is used at the head of the data. By adding a header indicating, an area where addresses are not continuous can be obtained.

  When the power of the image forming apparatus is turned on and “1” is set in the boot command register 121 a by the printer control unit 101, this set value is input to the memory read control unit 122. The memory read control unit 122 reads control data from both the non-reboot area 111 and the reboot area 112 in response to the input of the set value. Then, the control data (light quantity control data) read from the reboot area 112 is sent to the control data register write control section 124, and the control data (control data other than the light quantity control data) read from the non-reboot area 111 is sent to the control data transfer section. Send to 125.

  The control data register write control unit 124 sets the received light amount control data by writing it in the control data register 123. The control data transfer unit 125 transfers control data other than the light amount control data (hereinafter, “other control data”) to the printer control unit 101, and the printer control unit 101 writes “other control data” to an internal register. To set.

  When the printer control unit 101 sets “1” in the reboot command register 121b at the time of reboot, this set value is output to the memory read control unit 122. The memory read control unit 122 reads control data (light quantity control data) from the reboot area 112 in response to the input of the set value. The read light amount control data is sent to the control data register write control unit 124 and is reset in the light amount control data register 123.

Here, the light amount control using the shading correction value and the light amount gain adjustment value which are the light amount control data set in the light amount control data register 123 will be described.
Since the light beam scanning device of the image forming apparatus performs writing by the raster writing method, the amount of light reaching the photosensitive member varies depending on the main scanning position due to the characteristics of the optical system. In general, the central portion of the image in the main scanning direction that joins the optical system perpendicularly has a high transmittance of the optical system, and the transmittance tends to decrease as it approaches the main scanning end of the image. Therefore, the amount of light emitted from the LD is changed according to the main scanning position to keep the amount of light on the photoconductor constant. This correction of the characteristics of the optical system is called shading correction.

  In general, shading correction measures the characteristics of an optical system when assembling a light beam scanning device, and stores the information in a nonvolatile memory (the latter in this embodiment) mounted on the main body or the light beam scanning device. The light amount is corrected based on the information by the LD driver (in this embodiment, the light source control unit 104). This correction is performed when a change in shape or transmittance due to thermal expansion of the optical system occurs, so that it is necessary to appropriately perform correction in order to prevent density unevenness with respect to the image.

The light intensity gain adjustment value is a so-called APC (Auto
This parameter is for Power Control (automatic light control). This parameter is read from the non-volatile memory 109, set in the light amount control data register 123 as an initial value, and then generated by receiving a back emitted light amount proportional to the emitted light amount on the front side of the LD. It is updated so that a constant target emission light quantity can be obtained based on the current. That is, the light amount gain adjustment needs to be performed every time the LD is turned on.

  Therefore, in order to perform shading correction and light amount gain adjustment, it is necessary to read the shading correction and light amount gain adjustment values stored in the nonvolatile memory 109 and set them in the light amount control data register 123. Since the amount of control data stored in the nonvolatile memory 109 is enormous, it takes time and the load on the CPU increases when the CPU in the printer control unit 101 reads the data by serial communication. In addition, since the power source of the light source control unit 104 is turned off each time the power is turned off or energy saving is shifted, the setting data in the light quantity control data register 123 is cleared, and each time resetting is necessary. The load is also great.

  Therefore, in the present embodiment, at the same time when the power of the light beam scanning device 11 is turned on, as boot means for automatically booting the control data in the nonvolatile memory 109, a boot instruction register 121a, a memory read control unit 122, control data By providing the register write control unit 124 and the control data transfer unit 125, it is possible to reduce the load on the CPU in the printer control unit 101 when the power is turned on.

  On the other hand, the non-volatile memory 109 stores, as “other control data”, a write unit adjustment value for correcting a write position shift of each color and a process LD current value. The adjustment value for the writing unit and the LD current value for the process are necessary only when the power is turned on or when the unit is replaced, and are not necessary for the light amount control.

  For this reason, when all the control data in the non-volatile memory 109 is read at the time of rebooting as well as when the power is turned on, these data unnecessary for the light amount control are also read. In general, a nonvolatile memory has a certain amount of time for reading data as compared with an SRAM or the like, and therefore, a useless reading time is prolonged at reboot.

  Therefore, in this embodiment, at the time of rebooting, the memory read control unit 122 reads only the light amount control data from the reboot area 112 and does not read the control data stored in the non-reboot area 111, thereby reading unnecessary control data. To reduce the reading time.

  There is a possibility that the adjustment data for the writing unit and the LD current value for the process increase in proportion to the increase in the accuracy of correction, and the reading period may be increased accordingly. Therefore, by taking the configuration as described above, the time required for light amount adjustment at the time of rebooting can be minimized. In other words, the reboot instruction register 121b, the memory read control unit 122, and the control data register write control unit 124 as reboot means eliminate the wasted time associated with the resetting of control data unnecessary for the light amount control, and The time until completion is increased.

<Operation at power-on and energy-saving recovery>
FIG. 4 is a flowchart showing operations at the time of power-on and energy-saving return to the image forming apparatus according to the embodiment of the present invention. The flow in this figure starts when the power of the image forming apparatus is turned on or when the image forming apparatus returns from the energy saving state.

  Initial setting is performed first (step S1: initial setting process). This process is a process for setting system configuration information (number of LDs, connected device information such as post-processing apparatus) of the image forming apparatus, and is executed regardless of the operating state of the image forming apparatus.

  In this process, the printer control unit 101 sets “1” in the reboot command register 121 b in the light source control unit 104, so that it is stored in both the non-reboot area 111 and the reboot area 112 of the nonvolatile memory 109. The read control data is read by the memory read control unit 122. The control data read from the reboot area 112 is set in the light amount control data register 123, and the control data read from the non-reboot area 111 is set in a register in the printer control unit 101.

  Next, preparation for printing is performed (step S2: printing preparation step). In this step, exposure to the photosensitive drum 9 and driving of a polygon motor that is a base for generating a synchronization detection signal are performed. Next, LD lighting preparation is performed (step S3: LD lighting preparation process). In this process, preparation for detection of a synchronization detection signal and light amount adjustment (APC) are performed. If this step is not completed, it is not possible to proceed to the next print setting step, and it is not possible to accept a print job transmitted from the operation unit of the apparatus main body or a PC (personal computer).

  Next, print setting is performed (step S4: print setting step). In this step, settings are made based on printing conditions such as the size of image data to be formed on the paper 4. After the print setting, printing is executed (step S5: print execution step). After printing is performed, post-print setting is performed (step S6: post-print setting step). In this step, the light source 105 is turned off and the polygon motor is stopped so that unnecessary exposure does not occur.

  When the door of the image forming apparatus is opened or closed in order to eliminate an abnormal state such as a paper jam or when the user presses the reset button, the setting is performed again from the preparation for lighting the LD after the recovery process. FIG. 5 is a flowchart showing the contents of the recovery process.

  When the recovery process starts, the printer control unit 101 sets “1” in the reboot command register 121b in the light source control unit 104 (step S11). The set value “1” of the reboot instruction register 121b is sent to the memory read control unit 122 (step S12).

  Upon receiving the set value “1” of the reboot command register 121b, the memory read control unit 122 reads the light amount control data stored in the reboot area 112 of the nonvolatile memory 109 (Step S13). This light amount control data is sent to the control data register write control unit 124 and is reset in the light amount control data register 123 (step S14). After this recovery process, the process proceeds to the LD lighting preparation step (step S3), and the light amount adjustment is performed using the light amount control data reset in the light amount control data register 123.

  As described above, in the image forming apparatus according to the present embodiment, since the nonvolatile memory 109 is divided into the non-reboot area 111 and the reboot area 112, unnecessary memory access can be eliminated. Time can be shortened. As a result, the timing for accepting a print job after returning from the abnormal process can be advanced, and as a result, the startup time of the entire system can be shortened and the waiting time for a print job request can be reduced.

  4 ... paper, 11 ... light beam scanning device, 9, 9BK, 9C, 9M, 9Y ... photosensitive drum, 10BK, 10C, 10M, 10Y ... charger, 12BK, 12C, 12M, 12Y ... developer, 13BK, 13C , 13M, 13Y ... neutralizer, 15BK, 15C, 15M, 15Y ... transfer device, 25 ... intermediate transfer belt, 121a ... boot command register, 121b ... reboot command register, 122 ... memory read control unit, 123 ... light quantity control data register , 124... Control data register write control unit, 125... Control data transfer unit.

JP 2006-68927 A JP 2010-278560 A

Claims (5)

An image provided with a light beam scanning device and stored in a non-volatile memory and used to control lighting of the light source of the light beam scanning device by setting control data unique to the light beam scanning device including light amount control data in a register A forming device,
Boot means for reading the control data stored in the non-volatile memory and setting the register when the power of the image forming apparatus is turned on;
Reboot for reading the light amount control data from the nonvolatile memory and setting the light amount control data in the register when there is a need to reset the light amount control data set in the register while the image forming apparatus is powered on Means,
An image forming apparatus. The image forming apparatus according to claim 1,
The situation in which the light amount control data needs to be reset is at least one of opening / closing a front door of the image forming apparatus, pressing a reset button, and changing a print setting. The image forming apparatus according to claim 1,
The light beam scanning device includes an image forming apparatus including the boot unit, the reboot unit, and a light amount control data register in which the light amount control data is set. The image forming apparatus according to claim 3.
The boot unit and the reboot unit include a memory read control unit that reads the control data from the nonvolatile memory, and a register write control unit that sets the control data read by the memory read control unit in the light amount control data register And a boot / reboot output means for outputting to the memory read control section that the image forming apparatus is turned on and that the light quantity control data needs to be reset. apparatus. The image forming apparatus according to claim 4.
The boot / reboot output means is a register in which a main body control unit of the image forming apparatus is set with a boot command based on the power-on and a reboot command based on the occurrence of a situation that requires resetting of the light amount control data. Forming equipment.

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