JP2007007935A - Image forming apparatus and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which manufacturing cost can be reduced. <P>SOLUTION: An image processor is constituted of a controller section and an engine section. An amount L for adjusting the image output position in the feeding direction is acquired (S201). A minimum unit N of image adjustment in the feeding direction at the controller section is acquired (S203). An operation of L÷N is performed and the integer part of quotient is transmitted to the controller section 601 (S205). The controller section adjusts the image output position in the feeding direction within the range of its capacity. Remainder of L÷N is calculated as a correction amount at the engine section (S207). Based on that correction amount, the engine section performs phase control thus adjusting the image position. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and a method for controlling the image forming apparatus, and more particularly to an image forming apparatus such as a printer or a copying machine that prints an image by operating an image forming unit, and a method for controlling the image forming apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus that forms an image on a sheet such as an MFP (Multi Function Peripheral), a copying machine, or a printer is known.

  In an image forming apparatus for a color image typified by a tandem method, an image created so as not to cause a color shift when transferring an image created by an image forming unit of four colors of cyan, magenta, yellow, and black to a transfer member. It is necessary to adjust the position (writing position). In general, any color is defined as a reference color, and the position of the other color is matched with the reference color to eliminate the color shift.

  In the case of an image forming apparatus using a scanning exposure unit, an image request (IREQ: Image Request) signal is turned on, and then a SOS (Start of Scan) signal, which is a reference signal for starting scanning for each scan, is started. In general, after a predetermined number of counts, the position in the sub-scanning direction is controlled by starting output of image data.

Patent Document 1 below discloses a technique for switching the number of laser emission sources to be used in order to switch the scanning density in an image forming apparatus.
JP-A-1-299042

  A method of changing the recording position of the image data in the sub-scanning direction by using the IREQ signal and the SOS signal described above is a multi-beam image forming apparatus (using a plurality of laser diodes for one color, and a plurality of them in one scan. Is assumed to be used for an image forming apparatus that forms an image of a plurality of lines in one scan.

  Multi-beam is a technique for realizing an image forming apparatus capable of high-speed printing without advancing the scanning cycle of the scanning exposure unit, and can scan images of a plurality of lines by one scanning.

  When this technique is adopted, an image of a plurality of lines is written for one SOS signal output in one scan, so that, for example, a two-beam configuration (two laser diodes are provided and two in one scan is used). When the configuration of forming a line image) is employed, when the sub-scanning position is controlled by counting the SOS signal, the minimum control unit is two lines.

  In the case of a monochrome printing machine, even if the minimum unit is two lines, there was no particular problem in aligning the paper and the image. However, in the case of a color image forming apparatus such as a tandem method, from the viewpoint of preventing color misregistration. Causes the problem that the minimum unit is too large.

  As an inexpensive method for adjusting the image position in the sub-scanning direction in finer units, there is a method of performing phase control of the scanning unit.

  For example, when black and magenta color misregistration adjustment is performed using black as a reference color, the black SOS signal and magenta SOS signal are generated at the same time as half the black SOS cycle. If the state is changed so that a magenta SOS signal is generated at a timing shifted by a certain amount, the position of the image in the sub-scanning direction changes by one line in the case of the two-beam configuration.

  If the phase shift is made finer, the image position in the sub-scanning direction can be adjusted in finer units.

  However, regarding the phase control, the polygon mirror generally used in the scanning unit has a large inertia and poor responsiveness. Therefore, a predetermined time is required to adjust the phase, and the printing operation is interrupted during that time. There was a problem that it was necessary.

  As another method of adjusting the recording position in finer units than the method of changing the recording position of the image data in the sub-scanning direction by the IREQ signal and the SOS signal, the image adjustment in the sub-scanning direction is performed by changing the period of the SOS signal. Although there is a method that is performed more finely, if this method is adopted, there is a problem that the circuit configuration becomes complicated and the cost of the apparatus increases.

  As described above, there are two methods for adjusting the image position in the sub-scanning direction: (1) phase control and (2) finer adjustment units in the sub-scanning direction. It is common to select either method according to the price and performance of the forming apparatus.

  In recent years, there has been a tendency for product variations to increase in response to customer needs, and selecting a method in accordance with the characteristics of the product has become a design burden.

  In the case of an image forming apparatus, a print head unit including an image forming unit and a scanning exposure unit that are in charge of an electrophotographic process, a paper transport unit, a fixing unit, and the like, and an engine control unit that controls these mechanisms as one unit Is called an engine. Further, an image processing unit, an operation unit, an external IF unit such as a network, and a system control unit that controls these units are called a controller as one unit.

  Editing designs that create many product types by combining these engines and controllers are becoming common. In particular, it is important for development investment to reduce the number of engine types as much as possible while responding to a wide range of needs by increasing controller variations that are directly connected to customer needs.

  An object of the present invention is to provide an image forming apparatus and a method for controlling the image forming apparatus that can reduce the manufacturing cost from such a viewpoint.

  In order to achieve the above object, according to one aspect of the present invention, an image forming apparatus is an image forming apparatus including a photosensitive member, a scanning unit, and an exposure unit that exposes the photosensitive member using the scanning unit as an optical path. First acquisition means for acquiring the minimum unit of image adjustment of the controller unit, second acquisition means for acquiring the adjustment amount of the image position, the acquired minimum unit of image adjustment of the controller unit, and the acquired image Based on the position adjustment amount, a first calculation unit that calculates a correction amount in the controller unit, a transmission unit that transmits the correction amount calculated by the first calculation unit to the controller unit, and the acquired controller A second calculation unit that calculates a correction amount in the engine unit based on the minimum unit of image adjustment of the unit and the acquired adjustment amount of the image position; and a correction amount calculated by the second calculation unit Based on engine And an adjustment means for adjustment of the image position in parts.

  Preferably, the controller unit outputs the minimum unit of image adjustment in the sub-scanning direction to the engine unit, and the engine unit can obtain the output minimum unit of image adjustment in the sub-scanning direction. A scanning reference signal is output for each scan, and the controller unit outputs a predetermined number of lines of image data for each scanning reference signal to the engine unit. Phase control means for controlling the phase difference and phase determination means for determining the phase difference controlled by the phase control means in accordance with the adjustment amount of the image position, the minimum unit of image adjustment of the controller unit, and the predetermined number of lines.

  Preferably, when the predetermined number of lines is M and the minimum unit of image adjustment of the controller unit is N, the range of the phase difference determined by the phase determination unit is 0% or more and 100 × (N / M)% or less.

  Preferably, the image forming apparatus does not perform image formation until the adjustment of the image position in the engine unit is completed.

Preferably, the image forming apparatus includes a controller unit.
According to another aspect of the present invention, a method for controlling an image forming apparatus is a method for controlling an image forming apparatus including a photosensitive member, a scanning unit, and an exposure unit that exposes the photosensitive member using the scanning unit as an optical path. A first acquisition step of acquiring a minimum unit of image adjustment of the controller unit; a second acquisition step of acquiring an adjustment amount of the image position; and an acquired minimum unit of image adjustment of the controller unit; A first calculation step for calculating a correction amount in the controller unit based on the image position adjustment amount, a transmission step for transmitting the correction amount calculated in the first calculation step to the controller unit, and Based on the minimum unit of image adjustment of the controller unit and the acquired adjustment amount of the image position, the second calculation step for calculating the correction amount in the engine unit and the second calculation step are used. Based on the correction amount, and an adjustment step of adjusting the image position in the engine unit.

  According to these inventions, the minimum unit of image adjustment of the controller unit and the adjustment amount of the image position are acquired, and based on the acquired minimum unit of image adjustment of the controller unit and the acquired adjustment amount of the image position Then, the correction amount in the controller unit and the correction amount in the engine unit are calculated, and the image position is adjusted. As a result, it is possible to provide an image forming apparatus capable of reducing costs and a method for controlling the image forming apparatus.

FIG. 1 is a cross-sectional view of an image forming apparatus according to one embodiment of the present invention.
This image forming apparatus has four color image forming portions of cyan (C), magenta (M), yellow (Y), and black (K).

  Each color image forming unit has photoconductors 200Y, 200M, 200C, and 200K, an exposure unit that exposes the photoconductor with a laser beam, and a laser beam from the exposure unit for scanning exposure with a polygon mirror. The print heads 100Y, 100M, 100C, and 100K each having a scanning unit are included.

  The exposure unit and the scanning unit are integrally configured as a print head, and are arranged for four colors of cyan, magenta, yellow, and black. In FIG. 1, the print heads 100Y, 100M, 100C, and 100K are collectively referred to as the print head 100, and the photoconductors 200Y, 200M, 200C, and 200K are collectively referred to as the photoconductor 200.

  Further, the image forming apparatus is provided with an intermediate transfer belt 300 that is used in common for the image forming units of the respective colors.

  Further, the image forming apparatus includes a scanner 407 for reading an original image, a paper feed cassette 401 for feeding paper, a manual feed tray 403, and a double-side unit for reversing paper when performing double-sided printing. 405, a punch unit 409 and punch waste box 411 that form punch holes in the paper, a folding unit 413 that performs processing for folding the paper, and a stapler 415 that performs stapling processing on the paper.

FIG. 2 is a diagram illustrating the configuration of the print head 100Y and the photoreceptor 200Y.
Referring to the drawing, the print head forms two lines of images, two laser diodes 103a and 103b (collectively referred to as laser diode 103Y), lenses 105a to 105d, and not shown. A polygon mirror 101Y rotated by a polygon motor, an SOS sensor 107 for outputting an SOS (Start Of Scan) signal indicating a reference position for outputting an image, and mirrors 109a and 109b are provided. By these mechanisms, the laser from the laser diode 103Y is scanned by the polygon mirror 101Y and reaches the photosensitive member 200Y.

  Note that the configurations of the print heads 100M, 100C, and 100K and the photoconductors 200M, 200C, and 200K are the same as those in FIG. 2, and thus description thereof will not be repeated.

  With such a configuration, a scanning exposure unit capable of exposing a plurality of lines by one scanning is configured. Note that the number of laser diodes is not limited to two, and as the number increases, the number of lines that can be formed in one scan increases.

FIG. 3 is a diagram illustrating a configuration of the image forming apparatus.
Referring to the drawing, the image forming apparatus includes a controller unit 601 and an engine unit 603.

  The engine unit 603 includes a print head unit including an image forming unit and a scanning exposure unit responsible for an electrophotographic process, a paper transport unit, a fixing unit, and other mechanisms, and an engine control unit that controls these mechanisms.

  The controller unit 601 includes an image processing unit, an operation unit, an external IF unit such as a network, and a system control unit that controls these units.

  It is possible to create a plurality of types of products by combining these engine part and controller part.

  From the engine unit 603 to the controller unit 601, an image request (IREQ: Image Request) signal and a video clock (VideoCLK) are output. Further, the engine unit 603 sends an SOS (Start of Scan) signal (SOS_Bk for each color), which is a reference signal for starting scanning for each scan, for each of black, cyan, magenta, and yellow. , SOS_C, SOS_M, SOS_Y) are output.

  After the image request (IREQ) signal is turned on, the SOS signal starts counting, and after a predetermined number of times, the output of image data is started. Thereby, the image position in the sub-scanning direction is controlled.

  Image data is output for two lines corresponding to two laser diodes for each color. The black two-line image data is indicated as VideoData_Bk1 and VideoData_Bk2, the cyan two-line image data is indicated as VideoData_C1 and VideoData_C2, the magenta two-line image data is indicated as VideoData_M1 and VideoData_Y2 as yellow The image data is indicated as VideoData_Y1 and VideoData_Y2.

  With such a configuration, a two-beam configuration in which two lines are written for one SOS signal is realized.

  In addition, the controller unit 601 and the engine unit 603 are connected by a communication line, so that data can be exchanged.

  When the engine unit 603 is connected to the controller unit 601 that can control the image writing position in the sub-scanning direction in units of one line, the controller unit 601 performs correction in units of one line and corrects less than one line that cannot be handled by the controller unit 601. Is adjusted by phase control of the scanning unit.

  When the engine unit 603 is connected to the controller unit 601 that can control the image writing position in the sub-scanning direction only in units exceeding one line, the controller unit 601 performs adjustment in units that can be adjusted by the controller unit 601. Correction that is less than the unit that can be adjusted by the unit 601 is adjusted by phase control of the scanning unit of the engine unit 603.

  In the present embodiment, the control range of the phase control of the scanning unit on the engine unit 603 side is made different by identifying the correction capability of the connected controller unit 601 in the sub-scanning direction.

  Thereby, it is possible to prevent the time required for the phase control from becoming unnecessarily long, to optimize the cost of the controller unit, to realize commonality of the engine, and to suppress development investment. As a result, many kinds of inexpensive products can be provided to customers.

FIG. 4 is a diagram illustrating a basic screen of the operation panel provided in the image forming apparatus.
Referring to the figure, the “color / monochrome switch” key is displayed on the left of the basic screen of the operation panel. By pressing this button, a color mode, a monochrome mode, and an auto mode (a mode in which the type of document is automatically determined and color / monochrome is switched) are set.

  In addition, a button for selecting paper, a button for setting a magnification, a button for selecting single-sided / double-sided copying, a numeric keypad, a copy start key, a stop key, and the like are arranged on the basic screen of the scanning panel. .

FIG. 5 is a block diagram illustrating a configuration of the image forming apparatus.
Referring to the figure, the image forming apparatus includes a CPU 501 for controlling the entire apparatus, a ROM 507 for storing programs and constants, a RAM 509 functioning as a work area during program execution, an interface control unit 511, and an extension. I / O513.

  A paper discharge device 515 and an image processing controller 525 are connected to the interface control unit 511.

  An external device 519 such as a computer, a FAX line 521, and a scanner device 523 are connected to the image processing controller 525, and signals from these devices are input. Connected to the image processing controller 525 are an LCD controller 503 for controlling an LCD included in the operation panel and a keyboard controller 505 for controlling input from a numeric keypad, a mode switching key, and the like. Laser diodes 103Y, 103M, 103C, and 103K are connected to the image processing controller 525 and the expansion I / O 513. As shown in FIG. 2, since each laser diode 103Y, 103M, 103C, 103K includes two laser diodes for forming an image for two lines, the laser diodes 103Y, 103M from the extended I / O 513 are included. , 103C, and 103K receive light emission control signals corresponding to eight diodes, and image processing controller 525 receives image data corresponding to the eight diodes to laser diodes 103Y, 103M, 103C, and 103K. In response to this, each diode emits light and forms an image on the photoreceptor.

  In addition, signals from various sensors 517 are input to the expansion I / O 513. The expansion I / O 513 is connected to various motors, various solenoids, various clutches, various high-voltage power supplies, various relays 527, and a photoreceptor motor 529 for driving the photoreceptor.

  Further, the expansion I / O 513 is connected to the polygon motors 105Y, 105M, 105C, and 105K. Thereby, drive control of the polygon motors 105Y, 105M, 105C, and 105K is performed.

FIG. 6 is a timing chart of the operation of the controller unit 601 (part 1).
In FIG. 6, only the operation for one color is extracted. FIG. 6 illustrates a case where the image forming apparatus has a two-beam configuration and the minimum adjustment unit in the sub-scanning direction of the controller unit is two lines.

  As shown in the figure, after the IREQ signal is output from the engine unit, a predetermined number of SOS signals are counted, and when the predetermined number is reached, image data for two lines is output in accordance with VideoCLK. Of the two lines, the odd line data is VideoData1, and the even line data is VideoData2. Thereafter, every time an SOS signal is input, image data for two lines is output, and thus two lines are recorded for each scan (SOS signal).

  In this example, it is assumed that the controller unit adjusts the image position in the sub-scanning direction according to which SOS signal (scanning) the image for two lines is associated with. Accordingly, the adjustment in the sub-scanning direction is in units of two lines at a minimum.

  7 and 8 are timing charts of the operation of the controller unit 601 (part 2).

  7 and 8, only one color operation is extracted. 7 and 8 show a case where the image forming apparatus has a two-beam configuration and the minimum adjustment unit in the sub-scanning direction of the controller unit is one line.

  FIG. 7 shows a case where the correction amount is an even line, and FIG. 8 shows a case where the correction amount is an odd line.

  As shown in FIG. 7, when the correction amount is an even number line, as in the case of FIG. 6, after the IREQ signal is output from the engine unit, the SOS signal is counted a predetermined number, and when the predetermined number is reached. Two lines of image data are output in accordance with VideoCLK. Of the two lines, the odd line data is VideoData1, and the even line data is VideoData2. Thereafter, every time an SOS signal is input, image data for two lines is output, and thus two lines are recorded for each scan (SOS signal).

  In this example, it is assumed that the controller unit adjusts the image position in the sub-scanning direction according to which SOS signal (scanning) the image for two lines is associated with. Therefore, the minimum adjustment in the sub-scanning direction is two lines. Thereby, the adjustment for even lines is possible.

  As shown in FIG. 8, when the correction amount is an odd number line, after the IREQ signal is output from the engine unit, a predetermined number of SOS signals are counted, and when the predetermined number is reached, two lines worth of VideoCLK are matched. Output image data. In the output of the first image data, white data is output as the VideoData1 data. Also, the data of the first line is output to VideoData2. Thereafter, every time an SOS signal is input, image data for two lines is output, and thus two lines are recorded for each scan (SOS signal). Here, since white data is output as the first data, even-line data among the two lines is VideoData1, and odd-numbered data is VideoData2.

  In this example, the controller unit can replace the odd lines and the even lines in the image for two lines, so the adjustment in the sub-scanning direction is one line at the minimum. Thereby, it is possible to adjust an odd number of lines (minimum one line).

FIG. 9 is a timing chart (part 1) for phase control of the engine unit 601.
FIG. 9 shows a case where the image forming apparatus has a two-beam configuration and the minimum adjustment unit in the sub-scanning direction of the controller unit is two lines.

  Here, the output timing of the cyan SOS signal SOS_C is adjusted with reference to the black SOS signal SOS_Bk. Since the minimum adjustment unit in the sub-scanning direction of the controller unit is two lines, it is necessary to adjust the phase difference from 0% to 100% for fine adjustment of the writing position. That is, as shown in FIG. 9, the adjustment is performed between the phase difference minimum = 0% and the maximum = 100%.

FIG. 10 is a timing chart (No. 2) for phase control of the engine unit 601.
FIG. 10 shows a case where the image forming apparatus has a two-beam configuration and the minimum adjustment unit in the sub-scanning direction of the controller unit is one line.

  Here, the output timing of the cyan SOS signal SOS_C is adjusted with reference to the black SOS signal SOS_Bk. Since the minimum adjustment unit in the sub-scanning direction of the controller unit is one line, it is necessary to adjust the phase difference from 0% to 50% for fine adjustment of the writing position. That is, as shown in FIG. 10, the adjustment is performed between the phase difference minimum = 0% and the maximum = 50%.

  As shown in FIGS. 9 and 10, by adjusting the output of the SOS signal, the sub-scanning direction of the image can be adjusted.

  When the number of lines (number of beams) formed in one scan is M and the minimum unit of image adjustment of the controller unit is N, the range of the phase difference adjusted by the engine unit is 0% or more, 100 × (N / M)% or less.

FIG. 11 is a diagram illustrating a method for realizing phase control.
Referring to the figure, the target phase change can be obtained after a certain response time by momentarily changing the clock frequency supplied to the polygon motor. In other words, in FIG. 11, it is assumed that the time difference between the black SOS signal that is the reference color and the cyan SOS signal that is not the reference color is in the relationship of a certain time difference t1. When this is changed to t2 larger than t1, the desired reference phase difference is obtained by changing the frequency of the cyan reference clock for a moment and then returning to the original frequency while maintaining the waveform of the black reference clock. Can do.

  Since the reference clock can be generated using a CPU timer, the polygon motor can be controlled by using a register for setting the count number of the timer at a predetermined timing.

  During the response time, the rotation of the polygon mirror becomes unstable, so that the printing operation cannot be performed. Further, the amount of change in frequency is a time corresponding to “time to be changed” when viewed in a cycle. In FIG. 11, the phase is changed by adjusting the clock once. However, the total amount may be changed to a desired amount by dividing the phase into a plurality of times.

  Generally, a DC brushless motor driven by PLL control or the like is used as a polygon motor that rotationally drives a polygon mirror. In this motor, an encoder that outputs a predetermined number of pulses for one rotation of the motor is built in the motor, and the output of the encoder is input to the PLL control circuit.

  When a reference clock is input to the PLL control circuit to rotate the motor at a predetermined rotation speed, the PLL control circuit maintains the rotation speed of the motor so that the encoder output and the frequency and phase of the reference clock match.

FIG. 12 is a flowchart showing the basic operation of the engine unit 603 of the image forming apparatus.
Referring to the figure, an initial operation is performed in step S101. In step S103, input port reading processing is performed. In step S105, the received data is analyzed.

  In step S107, it is determined whether a print request has been made. If YES, processing for determining a print mode (color mode or monochrome mode) is performed in step S109.

  In step S111, control for determining the phase of the polygon mirror of the engine unit 603 is performed. Processing for controlling the scanning unit is performed in accordance with the phase determined in step S113. These processes will be described later.

  In step S115, the other image forming units are controlled, and in step S117, it is determined whether the image forming unit is to be in a standby state (to enter a wait state). Here, the wait state is set when either the phase control of the scanning unit or the control of the other image forming unit enters the wait state.

  If there is no wait condition, it is determined in step S119 whether a jam (JAM) has occurred, and if NO, it is determined in step S121 whether the print prohibition flag is set.

  If NO is determined in the step S121, it is determined whether or not another print prohibition flag is set in a step S123. If NO, a printing operation is performed in a step S125.

  Thereafter, jam detection and release processing is performed in step S127, and other processing is performed in step S129. Further, output port setting processing is performed in step S131, and processing from step S103 is performed.

  If NO in step S107 or if there is a wait condition in step S117, the process proceeds to step S127 as it is.

  If YES in any of steps S119, S121, and S123, the process proceeds to step S127.

FIG. 13 is a flowchart showing processing of the phase determination control (S111) of FIG.
Referring to the figure, in step S201, an amount L for adjusting the position of the image in the sub-scanning direction is acquired. This may be acquired from the controller unit 601 through a communication line, or may be held by the engine unit 603. L is an amount indicating how many lines the output position of the image is to be shifted.

  In step S203, the minimum unit N of image adjustment in the sub-scanning direction of the controller is acquired from the controller unit 601 by communication. N is an amount indicating the image adjustment capability of the controller (unit: line).

  In step S 205, L ÷ N is calculated, and the integer part (α) of the quotient is transmitted to the controller unit 601. Thereby, the controller unit 601 adjusts the image output position in the sub-scanning direction within the range of its own ability.

  In step S207, the remainder of L / N (β) is calculated as a correction amount in the engine unit 603. Since the remainder of L ÷ N is β, the value of β is always less than N.

  In step S209, 100 × (β / M) [%] is calculated as the phase difference. Here, M is the number of lines output by the image forming apparatus in one scan. In step S211, rounding is performed as necessary to determine the phase difference.

For example, assuming that the sub-scan image position adjustment amount L is 4.2 lines, the controller minimum adjustment unit N is 1 line, and the number M of lines output by the image forming apparatus in one scan is 2 lines.
L / N = 4.2
α = 4
β = 0.2
100 × (β / M) = 100 × (0.2 / 2) = 10 [%]
Thus, the controller unit 601 performs correction for shifting the image for four lines in the sub-scanning direction, and the engine unit 603 performs 10% phase control. As a result, the desired 4.2 line position can be adjusted.

FIG. 14 is a flowchart showing the phase control (S113) processing of FIG.
Referring to the figure, it is determined in step S301 whether the wait cancellation timer is set. If NO, it is determined whether the phase difference requested in step S303 is different from the current phase difference. If YES, a wait state is set in phase control in step S305, and control for switching to the phase requested in step S307 is performed (see FIG. 11). In step S309, a wait cancel timer is set.

  If YES in step S301, the timer is subtracted in step S311. In step S313, it is determined whether the timer value is “0”. If YES, the phase control wait state is reset.

  With the above processing, the polygon mirror is set at a predetermined phase. In addition, the timer is kept in a wait state until the rotation of the polygon mirror is stabilized, so that the position of the image can be accurately adjusted.

[Effects of the embodiment]
As described above, according to the present embodiment, timing adjustment from the IREQ signal to the start of image data output (processing in the controller unit) and phase adjustment with respect to the reference color of the polygon mirror (processing in the engine unit) The print position in the sub-scanning direction can be corrected.

  Further, the image forming apparatus performs correction on the controller side based on information on the minimum correction unit on the controller side obtained from the controller unit. The correction on the controller side is a multiple of the minimum correction unit on the controller. The phase control is performed with respect to the reference color of the polygon mirror in FIG.

  Thus, by identifying the correction capability of the connected controller unit in the sub-scanning direction, the control range of phase control of the engine-side scanning unit can be varied. Therefore, it is possible to prevent the time required for the phase control from becoming unnecessarily long under the connected controller.

  As a result, the cost of the controller can be optimized, the engine can be shared, and the number of engine types can be reduced as much as possible while responding to a wide range of needs by increasing the variations of the controller part directly connected to customer needs. Therefore, development investment can be suppressed, and as a result, many kinds of inexpensive products can be provided to customers.

  Note that the processing in the above-described embodiment may be performed by software or by using a hardware circuit.

  In addition, a program for executing the processing in the above-described embodiment can be provided, and the program is recorded on a recording medium such as a CD-ROM, a flexible disk, a hard disk, a ROM, a RAM, and a memory card and provided to the user. You may decide to do it. The program may be downloaded to the apparatus via a communication line such as the Internet.

  Thus, the above-described embodiments disclosed herein are illustrative in all respects and are not restrictive. The technical scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a cross-sectional view of an image forming apparatus in an embodiment of the present invention. FIG. 3 is a diagram illustrating a configuration of a print head 100Y and a photoreceptor 200Y. 1 is a diagram illustrating a configuration of an image forming apparatus. 3 is a diagram illustrating a basic screen of an operation panel provided in the image forming apparatus. FIG. 1 is a block diagram illustrating a configuration of an image forming apparatus. FIG. 10 is a diagram illustrating a timing chart (part 1) of an operation of a controller unit. FIG. 10 is a diagram illustrating a timing chart (part 2) of the operation of the controller unit. FIG. 10 is a diagram illustrating a timing chart (part 2) of the operation of the controller unit. FIG. 6 is a timing chart (part 1) for phase control of an engine unit 601. FIG. 8 is a timing chart (part 2) for phase control of the engine unit 601. It is a figure which shows the implementation | achievement method of phase control. 4 is a flowchart showing a basic operation of an engine unit 603 of the image forming apparatus. It is a flowchart which shows the process of the phase determination control (S111) of FIG. It is a flowchart which shows the process of the phase control (S113) of FIG.

Explanation of symbols

  100Y, 100M, 100C, 100K Print head, 103a, 103b Laser diode, 103Y, 103M, 103C, 103K Laser diode, 105Y, 105M, 105C, 105K Polygon motor, 200Y, 200M, 200C, 200K Photoconductor, 201Y, 201M, 201C, 201K developing device, 300 intermediate transfer belt, 501 CPU, 601 controller unit, 603 engine unit.

Claims (6)

A photoreceptor,
Scanning means;
An image forming apparatus comprising: an exposure unit that exposes the photosensitive member using the scanning unit as an optical path;
First acquisition means for acquiring a minimum unit of image adjustment of the controller unit;
Second acquisition means for acquiring an adjustment amount of the image position;
First calculating means for calculating a correction amount in the controller unit based on the acquired minimum unit of image adjustment of the controller unit and an adjustment amount of the acquired image position;
Transmitting means for transmitting the correction amount calculated by the first calculating means to the controller unit;
Second calculating means for calculating a correction amount in the engine unit based on the acquired minimum unit of image adjustment of the controller unit and the acquired adjustment amount of the image position;
An image forming apparatus comprising: an adjusting unit that adjusts an image position by the engine unit based on the correction amount calculated by the second calculating unit. The controller unit outputs a minimum unit of image adjustment in the sub-scanning direction to the engine unit,
The engine unit can obtain the minimum unit of image adjustment in the output sub-scanning direction,
The scanning means outputs a scanning reference signal for each scanning,
The controller unit outputs a predetermined number of lines of image data to the engine unit for each scanning reference signal,
The engine part is
Phase control means for controlling the phase difference of the non-reference color scanning means with respect to the reference color scanning means;
The phase determination unit according to claim 1, further comprising: a phase determination unit that determines a phase difference controlled by the phase control unit according to an adjustment amount of the image position, a minimum unit of image adjustment of the controller unit, and the predetermined number of lines. Image forming apparatus. The predetermined number of lines is M,
When the minimum unit of image adjustment of the controller unit is N,
The image forming apparatus according to claim 2, wherein a range of the phase difference determined by the phase determining unit is 0% or more and 100 × (N / M)% or less.   The image forming apparatus according to claim 1, wherein image formation is not performed until image position adjustment in the engine unit is completed.   The image forming apparatus according to claim 1, further comprising the controller unit. A photoreceptor,
Scanning means;
An image forming apparatus control method comprising: an exposure unit that exposes the photoconductor using the scanning unit as an optical path;
A first acquisition step of acquiring a minimum unit of image adjustment of the controller unit;
A second acquisition step of acquiring an adjustment amount of the image position;
A first calculation step of calculating a correction amount in the controller unit based on the acquired minimum unit of image adjustment of the controller unit and the acquired adjustment amount of the image position;
A transmission step of transmitting the correction amount calculated in the first calculation step to the controller unit;
A second calculation step of calculating a correction amount in the engine unit based on the acquired minimum unit of image adjustment of the controller unit and the acquired adjustment amount of the image position;
An image forming apparatus control method comprising: an adjustment step of adjusting an image position by the engine unit based on the correction amount calculated in the second calculation step.

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