JP2006244132A - Printing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem in which an image shift is not achieved in a DL generation stage in BDL though it is ideal that the shift is performed in the DL generation stage since the image shift such as a binding margin or an XY offset is performed in the DL generation stage or in the case of engine transfer after rendering and the direction and amount of the shift are generally restricted in the latter case. <P>SOLUTION: The image shift in a main scanning direction is performed in generating DL by the BDL. The image shift in a sub-scanning direction is performed in transferring the image to the engine. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printing system in which a printer driver generates drawing data in band units and transmits the drawing data to the printer, and the printer generates intermediate data in band units, renders, and transfers image data to a printing mechanism unit. The present invention relates to a method for shifting an output image for the purpose.

  In the past, when printing a document file on the host computer, the printer driver generally generates drawing data in units of pages, and the printer generally generates intermediate data for one page before rendering (development to an image). It was the target.

  However, in order to save printer memory and increase the speed, a method of dividing a drawing object into band units by a printer driver and transmitting drawing data to the printer in band units is becoming widespread. In this case, since the printer can generate and render intermediate data in band units, the size of the intermediate data storage memory can be kept small. Furthermore, since the rendering can be started immediately from the band where the intermediate data has been generated, the parallel processing between the intermediate data generation process and the rendering process is improved, and the throughput is improved.

  Note that when the output image is shifted for binding margin or the like, the printer driver moves the drawing position of the drawing object.

As a conventional example, for example, Patent Document 1 can be cited.
Japanese Patent Laid-Open No. 11-268372

  The image shift for the binding margin designated by the user from the user interface of the printer driver can be realized by the printer driver shifting the drawing position of the drawing object as described above, but the image is shifted due to a factor on the printer side. In some cases, it cannot be realized.

  For example, this is the case where a print job sent from a printer driver is stored in a hard disk in the printer, and printing is performed again after changing the binding margin or single-sided / double-sided setting according to a user instruction. This also corresponds to an image shift for correcting a deviation during paper conveyance of the printer. The amount of deviation during paper conveyance depends on the individual printer, and further depends on the paper feed tray, front / back, first page / continuous page, etc., so correction by image shift of the printer driver is virtually impossible.

  Therefore, it is preferable to shift the image on the printer side.

  When a general electrophotographic printer such as LBP shifts an image, there are roughly two methods. The first method is a method of shifting an image when the rendered image is transferred to the printing mechanism main body in band units. The second method is a method of shifting an image when intermediate data is generated or rendered.

  Next, problems when the printer shifts an image will be described. In the case of the first method, the possible range of image shift in the main scanning direction is narrow, and there is a problem that image wraparound occurs when the range is exceeded. In the case of the second method, since the intermediate data generation process and the rendering process are performed in units of bands, there is a problem that the image cannot be shifted in the sub-scanning direction.

  In order to solve the above-described problem, in the present invention, when the printer performs image shift, it is performed in two steps.

  First, image shift in the main scanning direction is performed when generating intermediate data or rendering intermediate data. The image shift at the time of generating intermediate data means generating intermediate data in which individual drawing positions of drawing data transmitted from the printer driver are shifted in the main scanning direction. Also, the image shift at the time of rendering does not perform the image shift at the time of generating the intermediate data, and when rendering it, the image image is output to the position shifted in the main scanning direction in the band memory, or the image is transferred to the band memory. This means that the image is shifted after output. In general, intermediate data generation processing is performed by software, but rendering processing is performed by hardware in many systems. When rendering processing is performed by hardware, whether or not an image can be shifted at the time of rendering depends on the hardware. Therefore, a method of performing image shifting at the time of generating intermediate data is general.

  Next, an image shift in the sub-scanning direction is performed when the image is transferred to the printing mechanism main body. This can be realized by delaying the video transfer start timing if the shift amount is negative and delaying the video transfer start timing if the shift amount is positive. When the shift amount is larger than the band height, it is not necessary to transfer some bands at the head or the end.

  According to the present invention, the printer driver sends drawing data in band units, the printer generates intermediate data in the band units, further generates image data in the band units, and further prints the image data in the band units. In a printing system that transfers images to a printing unit, an image shift method is divided into a main scanning direction and a sub-scanning direction, whereby an arbitrary image shift can be realized on the printer side.

  Since an arbitrary image shift can be realized on the printer side, when printing data stored in the hard disk of the printer is printed again, it is possible to change and output the binding margin and single / double-sided settings.

  Hereinafter, the present invention is applied to LBP and will be described in more detail with reference to the drawings.

  Before describing the configuration of this embodiment, the configuration of an LBP to which this embodiment is applied will be described with reference to FIG.

  FIG. 1 is a cross-sectional view showing the internal structure of the LBP of the embodiment.

  In the figure, reference numeral 100 denotes an LBP main body, and this LBP is a paper size designation command, a character print command, various graphic drawing commands, an image drawing command, a color designation command, etc. supplied from a computer connected to the LAN (201 in FIG. 2). A corresponding character pattern, figure, image, or the like is created according to the above, and an image is formed on a recording sheet as a recording medium. Reference numeral 151 denotes a switch for operation and an operation panel on which an LED display or an LCD display for displaying the status of the printer is arranged. Reference numeral 101 denotes a printer that controls the entire LBP 100 and analyzes a character print command supplied from the computer. Control unit.

  The LBP in this embodiment converts RGB color information into M (magenta) C (cyan) Y (yellow) K (black), and forms and develops them in parallel. Has a development mechanism. The printer control unit 101 generates a print image for each MCYK, converts it into a video signal, and outputs it to each MCYK laser driver.

  The M (magenta) laser driver 110 is a circuit for driving the semiconductor laser 111, and switches on and off the laser beam 112 emitted from the semiconductor laser 111 in accordance with an input video signal. The laser beam 112 is swung in the left-right direction by the rotary polygon mirror 113 to scan the electrostatic drum 114. As a result, an electrostatic latent image of a character or figure pattern is formed on the electrostatic drum 114. The latent image is developed by a developing unit (toner cartridge) 115 around the electrostatic drum 114 and then transferred to a recording sheet.

  C (cyan), Y (yellow), and K (black) have the same image formation / development mechanism as M (magenta), and 120, 121, 122, 123, 124, and 125 are C (cyan) images. Formation / development mechanism, 130, 131, 132, 133, 134, 135 are Y (yellow) image formation / development mechanisms, 140, 141, 142, 143, 144, 145 are K (black) image formation / development mechanisms. Development mechanism. The individual functions are the same as those of the M (magenta) image forming / developing mechanism, and a description thereof will be omitted.

  A cut sheet is used as the recording paper, and the cut sheet recording paper is stored in a paper feed tray 102 mounted on the LBP and is kept at a certain height by a spring 103. A paper feed roller 104 and transport rollers 105 and 106 are used. Are taken into the apparatus, are placed on the sheet conveying belt 107, and pass through each image forming / developing mechanism of MCYK.

  Each MCYK toner (powder ink) transferred to the recording paper is fixed to the recording paper by heat and pressure by the fixing unit 108, and the recording paper is output to the upper part of the LBP main body by the conveying rollers 109 and 150.

  FIG. 2 is a block diagram showing a schematic configuration of the LBP control unit 101 shown in FIG.

  The LBP control unit inputs data including characters, graphics, image drawing commands and color information sent from the computer 201 connected via the LAN 216, and prints document information and the like in units of pages. I have to. An input / output interface unit 202 exchanges various types of information with the computer 201, and an input buffer 203 temporarily stores various types of information input via the input / output interface unit 202. Reference numeral 204 denotes a character pattern generator, which includes a font information part 219 in which attributes such as character width and height and the address of the actual character pattern are stored, a character pattern part 220 in which the character pattern itself is stored, and its reading. However, it consists of a control program. The reading control program is included in the ROM 217 and has a code conversion function for calculating the address of the character pattern corresponding to the character code when the character code is input.

  A RAM 205 includes a font cache area 207 for storing the character pattern output from the character pattern generator 204, and a storage area 206 for storing an external character font sent from the computer 201, the current printing environment, and the like. . As described above, by storing the pattern information once developed into the character pattern in the font cache area 207 as a font cache, it is not necessary to decode the same character again and develop the pattern when printing the same character. , Development to character patterns is faster.

  Reference numeral 208 denotes a CPU for controlling the entire control unit of the printer, and the entire apparatus is controlled by a control program of the CPU 208 stored in the ROM 217. Reference numeral 209 denotes an intermediate buffer which is an internal data group generated based on input data. After the reception of data for one page is completed and converted into simpler intermediate data and stored in the intermediate buffer, it is rendered in band units by the renderer 210 and is stored in the band buffer 211 as an RGB image of 8 bits for each color. Is output.

  The RGB image output to the band buffer is converted into a 1-bit MCYK image for each color by the halftoning processor 212, separated into MCYK planes, and stored in the spool memory 213. The MCYK image stored in the spool memory 213 is compressed and held for each plane. When the data of all bands for one page is stored, the printing mechanism unit 215 of the page printer is activated. The MCYK image is expanded for each plane, converted into a video signal by the output interface unit 214, and output to the printer printing unit 215.

  As described above with reference to FIG. 1, in the LBP in this embodiment, since MCYK image formation / development is performed in parallel, the output interface unit 214 includes an M output interface unit, a C output interface unit, a Y output interface unit, K Each of the four interface units of the output interface unit independently reads a plane image from the spool memory 213, converts it into a video signal, and outputs it to the laser drivers 110, 120, 130, and 140 of each plane.

  Reference numeral 218 denotes a non-volatile memory composed of a general EEPROM or the like, and is hereinafter referred to as NVRAM (Non Volatile RAM). The NVRAM 218 stores panel setting values designated on the operation panel 151 and the like.

  The ROM 217 includes analysis of data input from the computer 201, generation of intermediate data, a control program for the printing mechanism main body 215, a color conversion table from the RGB color space to the MCYK color space, and the like.

  The hard disk 221 can record arbitrary information, and no information is lost even when the power is turned off.

  FIG. 3 is a diagram for explaining that a page is divided into bands and processed. In the figure, reference numeral 300 denotes A4 vertical size paper. In this embodiment, A4 portrait paper is divided into six areas of bands 301, 302, 303, 304, 305, and 306 and processed.

  The printer driver of the host computer 201 determines which band a drawing object such as a character, various graphics, and an image covers from its position and size, divides the drawing object into band units, and further divides it into bands 301 and 302. , 303, 304, 305, 306 in this order. The drawing objects divided and sorted in band units are converted into drawing commands in band units in order from the first band and transmitted to the printer.

  The user can specify the position and width of the binding margin from the user interface of the printer driver. FIG. 4 shows a user interface for setting a binding margin in the printer driver. In the figure, reference numeral 400 denotes a window displayed on the screen of the host computer 201, which is displayed when the user sets a binding margin. Reference numeral 401 denotes a field for inputting a binding margin width. Reference numeral 402 denotes an area for designating the binding margin position, which designates the binding margin position from the top, bottom, left, or right of the sheet. When the user finishes setting the binding margin, the user clicks the button 403, and the setting is notified to the printer. If the button 404 is clicked, the binding margin setting is cancelled. Information on the set binding margin position and width is transmitted to the printer as the header of the print job data. For example, when the setting is made as shown in FIG. 4, the binding margin position and width information transmitted to the printer is as follows.

Bind-Margin = 5.5 mm <cr>
Bind-Edge = left <cr>
It is. <Cr> is hexadecimal 0D.

  FIG. 5 is a diagram for explaining the configuration of the intermediate buffer 209. When the generation of a page is started, an area is first reserved to hold the start address of the intermediate data of each band. This area is called a page head area. In the figure, 500 is the page top area of the Nth page. Immediately after the start of page generation, the start address of any band is not set in the page start area, and the start address of that band is set in the page start area only after intermediate data of each band is generated. In the intermediate data area of each band, an area of an appropriate size is secured as necessary, and the area is expanded when the secured area is filled with intermediate data. If the area cannot be expanded as a continuous area, a new area is secured and a link by address is established. In this case, the search for the area is performed toward the lower address. If there is no empty area at the lower address, the search is performed from the head address of the intermediate buffer 209. FIG. 5 shows a state in which the generation of the intermediate data of the Nth page is completed and the intermediate data of the third band of the (N + 1) th page is generated. Reference numerals 501, 502, 503, 504, 505 and 506 are intermediate data of the bands 301, 302, 303, 304, 305 and 306 corresponding to the Nth page, respectively. The intermediate data of the Nth page is rendered by the renderer 210 if the band buffer 211 is empty, and the intermediate data of the rendered band is released. However, the band buffer 211 is not allocated with memory for holding images of a plurality of bands, and the empty state of the spool memory 213 substantially affects the rendering execution timing. Reference numeral 510 denotes a page head area of the (N + 1) th page, and reference numerals 511, 512, and 513 denote intermediate data of the bands 301, 302, and 303 corresponding to the (N + 1) th page, respectively.

FIG. 6 is a diagram for explaining the configuration of the page head region in more detail. In the figure, reference numerals 601, 602, 603, 604, 605, and 606 are storage areas for intermediate data head addresses of the corresponding bands 301, 302, 303, 304, 305, and 306, respectively. 611, 612, 613, 614, 615, 616 are areas for managing the states of the bands 301, 302, 303, 304, 305, 306,
0: Intermediate data is being generated
1: Intermediate data generation completed (rendering can be started)
2: Rendering completed (intermediate data can be released)
One of the values is set. In this state management area, the state management area of the band being generated is set to 1 by the band end notification command transmitted from the printer driver, and the process proceeds to the intermediate data generation process for the next band.

  Next, a process for generating intermediate data for one page by the CPU 208 will be described with reference to a flowchart of FIG. First, binding margin information is acquired in step S701. This is the binding margin position and width specified by the printer driver during normal printing as the header information of the print job, but may be changed when processing a print job stored in the hard disk 221. Get the changed setting value. Further, the correction value set on the operation panel 151 and stored in the NVRAM 218 is also read in this step. This correction value is set at the time of factory shipment in order to correct an error in paper conveyance due to individual differences. In step S702, the actual shift amount is calculated. Since only the image shift in the main scanning direction is performed at the intermediate data generation stage, the shift amount is positive if the binding margin position is the left side of the paper, and the shift amount is negative if the binding margin position is the right side of the paper. When the binding margin position is the upper side or the lower side of the sheet, the image shift for the binding margin is not performed at this stage. The shift amount for the binding margin is converted from mm to dots, and the number of dots added to the number of dots set to correct the paper transport error in the main scanning direction is added at the intermediate data generation stage. This is the final image shift amount. When the shift amount is determined, the process proceeds to step S703 to start command analysis. First, in step S703, data is read from the input buffer memory 203, and one instruction of the PDL command is analyzed. In step S704, it is determined whether or not the command is a drawing command for characters, figures, images, and the like. Intermediate data corresponding to the instruction is generated and output to the band area targeted by the intermediate buffer 209. Then, the process returns to step S703 to analyze the next command. If it is not a drawing command, the process advances to step S707 to determine whether it is a band end command. If it is a band end command, the process proceeds to step S708, where 1 (intermediate data generation completion) is set in the state management area of the target band, and the intermediate data generation process for that band ends. In step S709, it is determined whether or not it is the last band of the page. If it is the last band, the generation processing of intermediate data for one page is ended. If it is not the final band, the process proceeds to step S710, the target band is changed to the next band, and the process returns to step S703. If it is another instruction, the process corresponding to the instruction is performed in step S711, and the process returns to S703. This is, for example, a command for specifying a character size, but since it is not directly related to the present invention, a description thereof will be omitted.

  Next, the rendering process will be described with reference to the flowchart of FIG. The rendering process is performed by a renderer 210 controlled by the CPU 208. The rendering process is performed in parallel with the intermediate data generation process described above, but is performed by a task having a higher priority than the intermediate data generation process. This task is called a rendering task. In the rendering task, the state of the intermediate buffer 209 is polled, and it is checked in step S801 whether or not there is a band that can be rendered, that is, a band in which 1 (intermediate data generation completion) is set in the state management area. If it does not exist, it is determined again at a predetermined polling interval. If there is a band that can be rendered, the process advances to step S802 to determine whether or not there is a free space in the spool memory 213. In order to ensure normal operation, an area where a halftone CMYK plane image can be stored in an uncompressed state is required. However, since CMYK plain images are actually compressed, only a few percent of them are consumed for normal images. If the spool memory 213 has no space for storing the CMYK plane image in an uncompressed state, the determination is again made at a predetermined polling interval. If the spool memory 213 is available, the process proceeds to step S803, where the renderer 210 sets the intermediate data address of the band and the address of the band buffer 211 to execute rendering. The rendering result is output to the band buffer 211 as an RGB image. When rendering is completed, the process proceeds to step S804, where the halftoning processor 212 converts the image into a CMYK color 2BPP image, outputs the image to the spool memory 213, and further compresses each plane. Finally, in step S805, 2 (rendering completion) is set in the band state management area of the target band, and the process returns to step S801.

  Next, an image transfer process for transferring an image of one page spooled in the spool memory 213 to the print mechanism unit 215 for each band will be described with reference to a flowchart of FIG. Note that the description here relates to one of the CMYK planes, and this processing is actually performed for each CMYK plane.

  First, in step S901, the first band and the last band to be transferred are determined. When the image shift amount in the sub-scanning direction is 0, all bands 301, 302, 303, 304, 305, and 306 are transferred. For example, the binding margin position is set on the upper side of the sheet. In the case where the image shift amount is in the plus direction and is higher than the height of the band 306 as in the case, the band 306 need not be transferred. Further, when the image shift amount is equal to or greater than the sum of the heights of the bands 305 and 306, the band 305 need not be transferred. Conversely, if the image shift amount is in the minus direction and is equal to or higher than the height of the band 301 as in the case where the binding margin position is set at the lower side of the sheet, the band 301 need not be transferred. Furthermore, when the image shift amount is equal to or greater than the sum of the heights of the bands 301 and 302, the band 302 need not be transferred. In step S901, the first band and the last band to be transferred are determined from the amount of image shift in the sub-scanning direction and the height of each band. In step S901, when the image shift amount is in the plus direction, the timing for starting the transfer of the first band is also determined. Specifically, the transfer start is delayed by an amount corresponding to the image shift amount. Conversely, when the image shift amount is in the minus direction, it is determined from which scan line of the band the transfer is to be started with respect to the first band to be transferred. In addition, when the image shift amount is in the plus direction, up to which scan line is transferred for the last band to be transferred is determined. This is a process for cutting an image that protrudes from the paper.

  In step S902, the printing mechanism unit 215 is activated. As a result, the printing mechanism unit 215 starts rotation of the paper transport roller and the rotary polygon mirror and the temperature rise of the fixing device 108, and starts feeding from the paper cassette 102 when these are ready for printing. In step S903, the first band is transferred. Note that the start timing of the transfer of the first band and the scan line of the band from which the transfer is started are determined in step S901. In step S904, the target band number is updated, and in step S905, it is determined whether it is the last band to be transferred. If it is not the last band to be transferred, the process proceeds to step S906 to transfer the target band, and the process returns to step S904 to update the target band number. If it is the last band to be transferred, the process proceeds to step S907 to transfer the last band. Note that it is determined in step S901 which scan line is transferred to the last band.

  Since the image stored for each band in the spool memory 213 is compressed, the image is expanded in steps S903, S905, and S907 and transferred to the printing mechanism unit 215 by the output interface unit 214.

  As described above, in the present embodiment, the image shift in the main scanning direction is realized at the stage of generating the intermediate data, and the image shift in the sub scanning direction is realized when the image data is transferred to the printing mechanism unit. As a result, the printer driver sends drawing data to the printer in band units, and the printer generates an arbitrary image shift in the printer system that generates intermediate data, image data, and transfers to the printing mechanism unit in the band unit. It can be realized on the side.

  In addition, the present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. Needless to say, the present invention can also be applied to a case where the present invention is implemented by supplying a program to a system or apparatus. In this case, the storage medium storing the program according to the present invention constitutes the present invention. Then, by reading the program from the storage medium to the system or apparatus, the system or apparatus operates in a predetermined manner.

It is sectional drawing explaining the structure of the printing apparatus to which an Example is applied. It is a block diagram explaining the control structure of the main body shown in FIG. It is a figure showing the band division | segmentation of A4 vertical paper in an Example. FIG. 6 is a diagram illustrating a user interface for setting a binding margin in the printer driver in the embodiment. It is a figure which shows an example of a structure of the intermediate | middle buffer 209 in an Example. It is a figure which shows the structure of the page head area | region in the intermediate | middle buffer 209 in an Example. It is a flowchart for demonstrating the production | generation process of the intermediate data in an Example. It is a flowchart for demonstrating the rendering process in an Example. It is a flowchart for demonstrating the image transfer process in an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Printer body 101 Printer control unit 102 Paper feed cassette 103 Spring for lifting paper 104 Paper feed roller 105 Paper transport roller 106 Paper transport roller 107 Paper transport belt 108 Fixing device 109 Paper transport roller 110 Laser driver (for magenta)
111 Semiconductor laser emitting device (for magenta)
112 Laser beam (for magenta)
113 Rotating polygon mirror (for magenta)
114 Electrostatic drum (for magenta)
115 Toner cartridge (for magenta)
120 Laser driver (for cyan)
121 Semiconductor laser emitting device (for cyan)
122 Laser beam (for cyan)
123 Rotating polygon mirror (for cyan)
124 Electrostatic drum (for cyan)
125 toner cartridge (for cyan)
130 Laser driver (for yellow)
131 Semiconductor laser emitting device (for yellow)
132 Laser beam (for yellow)
133 Rotating polygon mirror (for yellow)
134 Electrostatic drum (for yellow)
135 Toner cartridge (for yellow)
140 Laser driver (for black)
141 Semiconductor laser emitting device (for black)
142 Laser beam (for black)
143 Rotating polygon mirror (for black)
144 Electrostatic drum (for black)
145 Toner cartridge (for black)
150 Paper transport roller 151 Operation panel 201 Computer 202 Input interface unit 203 Input buffer 204 Character pattern generator 205 RAM
206 Storage area for storing various registration data, printing environment, etc. 207 Font cache area 208 CPU
209 Storage area for storing print data 210 Renderer 211 Band buffer 212 Halftoning processor 213 Spool memory 214 Output interface unit to printing mechanism unit 215 Printing mechanism unit 216 LAN
217 ROM
218 NVRAM
219 Font information part 220 Character pattern part 221 Hard disk 300 A4 portrait paper 301 A4 portrait paper first band 302 A4 portrait paper second band 303 A4 portrait paper third band 304 A4 portrait paper fourth band 305 A4 portrait paper 5th band 306 6th band of A4 vertical paper 400 User interface window for binding margin setting 401 Binding margin width setting field 402 Binding margin position designation area 403 Binding margin setting completion button 404 Binding margin stop button 500 Intermediate data page head region 501 N page N 1st band intermediate data region 502 N page N 2nd band intermediate data region 503 N page N 3rd band intermediate data region 504 N page N 4th band region Intermediate data area 505 Nth page Band intermediate data area 506 Nth page 6th band intermediate data area 510 N + 1 page intermediate data page start area 511 N + 1 page 1st band intermediate data area 512 N + 1 page 2nd band intermediate area Data area 513 N + 1 page, third band intermediate data area 601 N page N, first band intermediate data start address area 602 N page N, second band intermediate data start address area 603 Area for storing start address of intermediate data of Nth page and third band 604 Area for storing start address of intermediate data of Nth page and fourth band 605 Area for storing start address of intermediate data of Nth page and fifth band 606 Stores start address of intermediate data of Nth page and 6th band Area 611 N-page first band state management area 612 N-page second-band state management area 613 N-page third-band state management area 614 N-page fourth-band state management area 615 N-page first 5-band state management area 616 N-page 6th band state management area

Claims (3)

The printer driver sends drawing data to the printer in band units, the printer generates intermediate data in the band units, further generates image data in the band units, and further transfers the image data in the band units to the printing mechanism unit. A printing system to transfer,
A main scanning direction image shift amount calculating means for calculating an image shift amount in the main scanning direction;
Sub-scanning direction image shift amount calculating means for calculating an image shift amount in the sub-scanning direction;
Main scanning direction image shifting means for shifting the image in the main scanning direction;
A printing system comprising: a sub-scanning direction image shifting unit that shifts an image in the sub-scanning direction.   The printing according to claim 1, wherein the image shift in the main scanning direction is performed when the intermediate data is generated in band units, and the image shift in the sub scanning direction is performed when the image data is transferred to the printing mechanism unit. system.   2. The printing according to claim 1, wherein the image shift in the main scanning direction is performed when image data is generated in a band unit, and the image shift in the sub scanning direction is performed when the image data is transferred to the printing mechanism unit. system.

Images