JP2006243908A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device capable of improving the quality of print image without increasing memory consumption. <P>SOLUTION: This device comprises a means changing meaning creation to a storage area of attribute information according to an input data format, a means adding attribute information to each pixel of raster data generated according to a drawing command, and a means interpreting the meaning of the attribute information added to the raster data according to the input data format at the time of executing image processing, and selecting an optimum image processing method. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as a printing apparatus controlled by a printer controller connected to a host computer or another device, and in particular, attribute information is provided for each pixel of raster data generated according to a drawing command. The present invention relates to an image forming apparatus that can be added to improve print image quality.

  In a conventional attribute information addition method in an image forming apparatus, attribute information is added to each pixel of raster data generated according to a drawing command to improve the print image quality. On the other hand, when more advanced image processing is desired, it is necessary to expand the area for storing attribute information and store the information, which increases the memory consumption.

As another conventional example, Patent Literature 1 and Patent Literature 2 can be cited.
JP 09-006899 A Japanese Patent Application Laid-Open No. 11-191832

  In the attribute information adding method in the conventional image forming apparatus, attribute information is added to each pixel of raster data generated according to the drawing command to improve the print image quality, while more detailed image processing is desired. In this case, it is necessary to enlarge and save the area for saving attribute information for each piece of information to be saved, and there is a problem that the amount of memory consumption increases.

  The present invention has been made in view of the above problems, and an image forming apparatus capable of improving print image quality without increasing memory consumption by changing the meaning of attribute information according to an input data format. It is intended to provide.

  The printing apparatus of the present invention that achieves the above object has the following configuration.

  A first invention according to the present invention is an image forming apparatus that generates print objects by analyzing print data based on a plurality of page description languages. In an image forming apparatus capable of processing a plurality of input formats, Page format determining means for determining the data format from the data format designation, first attribute information defining means for changing the definition of attribute information for each page according to the input drawing command and input data format, and input drawing Defined by raster generating means for generating a raster image from a command, attribute information adding means for generating and adding attribute information for each pixel of a raster image in accordance with a drawing command and an input data format, and the first attribute information defining means Processing method for determining an image processing method according to the attribute information definition A constant section, is that of providing an image processing means for performing the determined image processing by the image processing method determination means.

  According to a second aspect of the present invention, the data format determined by the page format determining means is a color space, and the attribute information area defined for each page based on the result of the input data format determination is “Gray”. Means is provided to mean “whether or not to guarantee” or “whether or not color conversion processing is designated by the user”.

  According to a third aspect of the present invention, there is provided automatic page format determination means for automatically determining the type of page format from input data.

  According to a fourth aspect of the present invention, there is provided an image forming apparatus that generates a drawing object by analyzing print data based on a plurality of page description languages. The image forming apparatus is capable of processing a plurality of input formats. Raster image generation means for generating a raster image from a drawing command, block division means for dividing the generated raster image into blocks, and automatic block format determination for automatically determining the format of the raster image divided into blocks for each block Means, second attribute information definition means for changing the definition of attribute information for each block according to the determined data format of the raster image, and the attribute information definition defined by the attribute information definition means and the generated Generate attribute information for each pixel according to the raster image The attribute information adding means to be added, the image processing method determining means for determining the image processing method according to the attribute information definition defined by the second attribute information defining means, and the image processing method determining means Image processing means for performing image processing is provided.

  According to a fifth aspect of the present invention, the data format determined by the block format determining means is a color space, and the attribute information area defined for each block based on the second attribute information defining means is “ Means are provided to mean “whether or not Gray is guaranteed” or “whether or not color conversion processing is designated by the user”.

(Function)
In this configuration, means for changing the meaning of the attribute information storage area according to the input data format, means for adding attribute information to each pixel of the raster data generated according to the drawing command, and input data when executing image processing By interpreting the meaning of the attribute information added to the raster data in accordance with the format and providing means for selecting an optimal image processing method, it is possible to improve the print image quality without increasing the memory consumption.

  As described above, according to the present invention, the means for changing the meaning of the attribute information storage area according to the input data format, and the means for adding the attribute information to each pixel of the raster data generated according to the drawing command And interpreting the meaning of the attribute information added to the raster data according to the input data format when executing image processing, and providing a means to select the optimal image processing method, improving print image quality without increasing memory consumption Can be achieved.

  First, a configuration example of a laser beam printer will be described as an example of an output device to which the embodiment of the present invention can be applied. The present embodiment can be applied not only to a laser beam printer but also to other types of output devices such as an ink jet printer and an MFP (Multi Function Printer).

  FIG. 1 is a block diagram showing the configuration of a laser beam printer as a first embodiment of the printing apparatus of the present invention, FIG. 2 is a diagram schematically showing the mechanism of the laser beam printer of FIG. 1, and FIG. It is a block diagram which shows the structure of the printer controller mounted in the laser beam printer of FIG.

  In FIG. 1, a data processing device 101 is, for example, a computer, and functions as a supply source of image information or a control device for a printer. In this embodiment, a laser beam printer (printer) is used as the image recording apparatus 102.

  The printer controller 103 generates bitmap data for each page based on the image information (for example, ESC code, page description language, etc.) supplied from the data processing apparatus 101 and sends it to the printer engine 105.

  The printer engine 105 forms a latent image on the photosensitive drum based on the bitmap data supplied from the printer controller 103, and transfers and fixes the latent image on a recording medium (electrophotographic method). Record.

  The panel unit 104 is used as a user interface. The user can instruct a desired operation by operating the panel unit 104. The panel unit 104 displays processing contents of the printer 102 and warning contents for the user.

  Next, the configuration of the laser beam printer taken up as an example of the embodiment in this example will be described with reference to FIG.

  FIG. 2 is a cross-sectional view illustrating the configuration of the tandem color printer 102.

  In the figure, 201 is a printer housing. Reference numeral 202 denotes an operation panel on which switches for giving various instructions to the user, LED displays for displaying messages, printer settings, and the like, LCD displays, etc. are arranged. It is one mode. Reference numeral 203 denotes a board accommodating portion that accommodates boards constituting the electronic circuit portions of the video controller 103 and the printer engine 105.

  A paper cassette 220 holds the paper (recording medium) S and has a mechanism for electrically detecting the paper size by a partition plate (not shown). Reference numeral 221 denotes a cassette clutch which takes out the uppermost sheet S of the paper S placed on the paper cassette 220 and feeds the taken paper S by a driving force transmitted from driving means (not shown). It has a cam that conveys up to. This cam rotates intermittently each time paper is fed, and feeds one sheet S corresponding to one rotation. Reference numeral 223 denotes a paper detection sensor that detects the amount of paper S held in each paper cassette 220.

  The paper feed roller 222 is a roller that conveys the leading edge of the paper S to the registration shutter 224. Reference numeral 224 denotes a registration shutter that can stop paper feeding by pressing the paper S.

  230 is a manual feed tray, and 231 is a manual paper feed clutch. The manual sheet feeding clutch 231 is used to convey the leading edge of the sheet S to the manual sheet feeding roller 232, and the manual sheet feeding roller 232 is used to convey the leading edge of the sheet S to the registration shutter 224. The paper S to be used for image recording is fed by selecting one of the paper cassette 220 and the manual feed tray 230.

  The printer engine 105 communicates with the video controller 103 in accordance with a predetermined communication protocol, selects one of the paper cassettes 220 from the manual feed tray 230 in accordance with an instruction from the video controller unit 103, and starts printing. In response to the instruction, the sheet S is conveyed from the corresponding sheet feeding means to the registration shutter 224. The printer engine 105 includes a paper feeding unit, a mechanism related to an electrophotographic process such as formation, transfer, and fixing of a latent image, a paper discharge unit, and a control unit thereof.

  204a, 204b, 204c, and 204d are image recording units having photosensitive drums 205a, 205b, 205c, and 205d, a toner holding unit, and the like, and form a toner image on the sheet S by an electrophotographic process. On the other hand, 206a, 206b, 206c, and 206d are laser scanner units that supply image information by a laser beam to the image recording unit.

  In the image recording units 204a, 204b, 204c, and 204d, a paper transport belt 250 that transports the paper S is stretched flat in the paper transport direction (from the bottom to the top in the figure) by a plurality of rotating rollers 251-254. In the most upstream area, the sheet is electrostatically attracted to the sheet conveying belt 250 by the attracting roller 225 to which a bias is applied. Further, four photosensitive drums 205a, 205b, 205c, and 205d are arranged in a straight line so as to face the belt conveyance surface, and constitute an image forming unit. In each of the image recording units 204a, 204b, 204c, and 204d, a charger and a developing device are disposed so as to sequentially surround the vicinity of the periphery of the photosensitive drum.

  In the laser scanner units 206a, 206b, 206c, and 206d, 207a, 207b, 207c, and 207d are laser units that drive a built-in semiconductor laser in accordance with an image signal (/ VIDEO signal) sent from the printer controller 103. And fire a laser beam. Laser beams emitted from laser units 207a, 207b, 207c, and 207d are scanned by polygon mirrors (rotating polygon mirrors) 208a, 208b, 208c, and 208d to form latent images on the photosensitive drums 205a, 205b, 205c, and 205d. To do.

  A fixing device 260 fixes the toner image formed on the paper S by the image recording units 204a, 204b, 204c, and 204d to the recording paper S by heat. A conveyance roller 261 discharges and conveys the paper S. A paper discharge sensor 262 detects a paper discharge state of the paper S. Reference numeral 263 denotes a paper discharge roller and double-sided printing conveyance path switching roller, which conveys the paper S in the paper ejection direction. If the paper S conveyance instruction is paper discharge, the paper S is discharged directly to the paper discharge tray 264. In the case of double-sided conveyance, immediately after the trailing edge of the paper S passes the paper discharge sensor 262, the rotation direction is changed to the reverse direction, and the paper S is conveyed to the double-sided printing conveyance path 270 by switching back. A sheet discharge amount detection sensor 265 detects the amount of sheets S stacked on the sheet discharge tray 264.

  Reference numeral 270 denotes a conveyance path for double-sided printing. The sheet S conveyed for duplex printing by the discharge roller / double-sided conveyance path switching roller 263 is conveyed again to the registration shutter 224 by the duplex conveyance rollers 271 to 274. It waits for a conveyance instruction to the image recording units 204a, 204b, 204c, and 204d.

  The printer 102 can be further equipped with optional units such as an optional cassette and an envelope feeder.

  Next, the configuration of the printer controller 103 will be described with reference to FIG.

  The printer controller 103 includes an input buffer (not shown) for inputting print data sent from the data processing device 101 and settings for instructing the operation of the device, and an output including a signal sent to the data processing device 101 and device information data. The host I / F unit 302 is provided with an output buffer (not shown) for temporarily storing data, and the host I / F unit 302 includes signals exchanged with the data processing device 101. The communication packet input / output unit is configured, and communication control with the data processing apparatus 101 is performed.

  The print data input via the host I / F unit 302 is given to the image data generation unit 303. The image data generation unit 303 analyzes input print data based on a predetermined analysis means (for example, PDL analysis processing), generates an intermediate language drawing object from the analysis result, and can be further processed by the printer engine 105 Bitmap data generation is performed. Specifically, print data is analyzed and object information is created by the analysis, and rasterization processing is performed in parallel with the creation of the object information. In this rasterization process, the display color RGB (additive color mixture) included in the print data is converted to YMCK (subtractive color mixture) that can be processed by the printer engine, the bit pattern and outline stored in advance from the character code included in the print data Performs conversion to font data such as fonts, creates bitmap data in page units or band units, applies pseudo-gradation processing using a dither pattern to the bitmap data, and allows printing processing in the printer engine Generate bitmap data.

  The created bitmap data is stored in the image memory 305. Reading of the bitmap data stored in the image memory 305 is controlled by the DMA control unit 308, and the control for reading the bitmap data from the image memory 305 by the DMA control unit 308 is performed based on an instruction from the CPU 309.

  Bitmap data read from the image memory 305 is transferred to the engine 105 as a video signal via the engine I / F unit 306. The engine I / F unit 306 includes an output buffer (not shown) that temporarily holds a video signal transferred to the engine 105, and an input buffer (not shown) that temporarily holds a signal sent from the engine 105. The engine I / F unit 306 constitutes an input / output unit for signals exchanged with the engine 105 and controls communication with the engine 105.

  Instructions relating to mode setting and the like issued by operation input from the panel unit 104 (shown in FIG. 1) are input via the panel I / F unit 301. The panel I / F unit 301 is connected between the panel unit 104 and the CPU 309. (The instruction to the printing apparatus such as the mode setting issued by the operation input can also be instructed via the host I / F unit 302 that performs bidirectional communication with the external connection device).

  The CPU 309 controls each block described above according to the mode instructed from the panel unit 104 or the data processing apparatus 101, and this control is executed based on a control program stored in the ROM 304. The control program stored in this ROM304 is an OS (operating system) for performing time-sharing control in units of load modules called tasks according to the system clock, and a plurality of load modules that are executed and controlled in units of functions by this OS It consists of. The control program including this load module is stored in an EEPROM (nonvolatile memory) 310 as necessary.

  A RAM 307 is used as a work area for arithmetic processing by the CPU 309. Each block including the CPU 309 is connected to the system bus 320. The system bus 320 includes an address bus and a system bus.

  Next, the processing path of input data in the printer controller of FIG. 3 is shown for each functional block with reference to FIG.

  Print data input from the external connection device through the host interface unit (302) is command-analyzed by the PDL analysis unit (303a), and then generated as a drawing object (intermediate language) by the drawing object generation unit (303b). It is temporarily recorded in the upper working memory (307).

  Then, the drawing memory is read from the working memory on the RAM as needed and rasterized (303c), and the image data finally recorded on the recording medium is developed into a bitmap image and stored in the image memory (305). 306) and recording on a recording medium is performed.

  In the printer control system configured as described above, FIGS. 5, 6, and 7 are flowcharts showing programs stored in the program ROM indicated by 304 in FIG.

  In the attribute information addition method in the conventional image forming apparatus, attribute information is added to each pixel of raster data generated according to the drawing command to improve the print image quality, while more detailed image processing is desired. However, there is a problem that an area for storing attribute information needs to be expanded and stored for each piece of information to be stored, which increases memory consumption.

  The program shown in the flowcharts of FIGS. 5, 6, and 7 improves on this point, and the print image quality is improved without increasing the memory consumption by changing the meaning of the attribute information according to the input data format. Is possible.

  The embodiment will be described below with reference to FIGS.

  Note that the processing inside the printing apparatus in this case is given as an example, and it is not always necessary to perform these operations.

  The data format of the page included in the print data input via the host interface and analyzed by the PDL analysis unit is confirmed (501), and it is determined whether the data format is CMYK designation or RGB designation (502). If CMYK is specified, the definition of the image processing bit part of the attribute information shown in FIG. 9 is determined to be “CMS presence / absence” (503). On the other hand, if the data format is RGB, the attribute shown in FIG. The definition of the image processing bit part of the information is set to “Gray compensation” (504) and stored in the program.

  Next, it is determined whether or not there is an ICC Profile designation for performing color matching from the user (505). When the ICC profile is designated, the designated ICC Profile is read from the nonvolatile storage device (506) and referred to by 506. The color matching process is executed according to the ICC profile (507).

  Next, a rendering command in the print data is analyzed to generate a raster image (bitmap data) (508), and attribute information is generated (509). In particular, the image processing bit is set in 503 or 504, and the attribute value is determined according to the attribute information definition held in the program.

  Further, according to the attribute information generated in 509, image processing is executed on the raster image generated in 508 with reference to the LUT and dither matrix stored in the nonvolatile storage device (510), and the generated bitmap image data Is stored in the image memory (511), and the process is terminated.

  The print data processing flow at this time is shown in FIG.

  An example of the configuration of attribute information is shown in FIG. 9, and an example of attribute values when processed in this embodiment is shown in FIG.

  As described above, it is possible to improve the print image quality without increasing the memory consumption by changing the meaning of the attribute information according to the input data format.

  In the first embodiment, the method for determining the definition of the attribute information according to the data format of the page included in the print data has been described. In the present embodiment, the page data format is generated from the raster image data generated by the rendering process. A method of automatically determining the definition of attribute information will be described.

  FIG. 6 is a flowchart showing an image processing method in this embodiment.

  For print data input via the host interface and analyzed by the PDL analyzer, it is determined whether the user has specified ICC Profile for color matching (601). The ICC Profile is read from the nonvolatile storage device (602), and color matching processing is executed according to the ICC Profile referenced in 602 (603).

  Next, a drawing command in the print data is analyzed to generate a raster image (bitmap data) (604), and the page data format is automatically determined from the generated raster image (605).

  Next, it is determined whether the data format automatically identified in 605 is CMYK designation or RGB designation (606), and if it is CMYK designation, the definition of the image processing bit part of the attribute information shown in FIG. Is set to `` CMS presence / absence '' (607), while if the data format is RGB, the definition of the image processing bit part of the attribute information shown in FIG. 9 is set to `` Gray compensation '' (608) Remember in.

  Next, attribute information is generated according to the raster image generated in 604 (609). At this time, in particular, the image processing bit is set in 607 or 608, and the attribute value is determined in accordance with the attribute information definition held in the program.

  Next, in accordance with the attribute information generated in 609, image processing is performed on the raster image generated in 603 with reference to the LUT and dither matrix stored in the nonvolatile storage device (610), and the generated bitmap Image data is stored in the image memory (611), and the process is terminated.

  The print data processing flow at this time is shown in FIG.

  An example of the configuration of attribute information is shown in FIG. 9, and an example of attribute values when processed in this embodiment is shown in FIG.

  As described above, by automatically determining the page data format and changing the meaning of the attribute information according to the automatically determined data format, it is possible to improve the print image quality without increasing the memory consumption.

  In the first and second embodiments, the method for determining the definition of attribute information according to the data format of the page has been described. However, in this embodiment, the raster image data generated by the rendering process is divided into blocks, and each block is divided. A method for automatically determining the data format and determining the definition of attribute information is described.

  FIG. 7 is a flowchart showing an image processing method in this embodiment.

  For print data input via the host interface and analyzed by the PDL analyzer, it is determined whether the user has specified ICC Profile for color matching (701). The ICC Profile is read from the non-volatile storage device (702), and color matching processing is executed according to the ICC Profile referenced in 702 (703).

  Next, a drawing command in the print data is analyzed to generate a raster image (bitmap data) (704).

  Next, the generated raster image is divided into arbitrary block sizes (705), and the block processing of 706 to 712 is repeated by the number of divided blocks.

  Automatically determine the data format of the block from the raster image divided into blocks (706), and determine whether the data format automatically determined in 706 is CMYK or RGB (707) In the case of CMYK designation, the definition of the image processing bit part of the attribute information shown in FIG. 9 is determined to be “CMS presence / absence” (708), while in the case where the data format is RGB, it is shown in FIG. The definition of the image processing bit part of the attribute information is set to “Gray compensation” (709) and stored in the program.

  Next, attribute information is generated according to the raster image generated in 704 (710). At this time, in particular, the image processing bit is set in 708 or 709 and the attribute value is determined according to the attribute information definition held in the program.

  Next, in accordance with the attribute information generated in 710, image processing is performed on the raster image generated in 704 with reference to the LUT and dither matrix stored in the non-volatile storage device (711), and the generated bitmap The image data is stored in the image memory (712), and the process is terminated.

  The print data processing flow at this time is shown in FIG.

  An example of the configuration of attribute information is shown in FIG. 9, and an example of attribute values when processed in this embodiment is shown in FIG.

  As described above, the rendered raster image is divided into blocks, the data format for each block is automatically determined, and printing is performed without increasing memory consumption by changing the meaning of attribute information according to the automatically determined data format. It is possible to improve the image quality.

1 is a block diagram showing a configuration of a laser beam printer as a first embodiment of a printing apparatus according to the present invention. The figure which shows typically the mechanism of the laser beam printer of FIG. FIG. 2 is a block diagram showing a configuration of a printer controller installed in the laser beam printer of FIG. 1. The figure which shows the input data processing in the printer controller of FIG. 3 according to the functional block. 3 is a flowchart showing image processing in Embodiment 1 of the present invention. 9 is a flowchart showing image processing in Embodiment 2 of the present invention. 10 is a flowchart showing image processing in Embodiment 3 of the present invention. The figure which modeled the processing flow of Examples 1-3 of this invention. The figure which modeled the content of the attribute information used in Examples 1-3 of this invention. An example of the attribute information produced | generated in Examples 1-3 of this invention.

Explanation of symbols

101 Data processor
102 Image recording device
103 Printer controller
104 Panel section
105 Printer engine
201 Printer housing
202 Operation panel
203 Board compartment
204a, 204b, 204c, 204d Image recording unit
205a, 205b, 205c, 205d Photosensitive drum
206a, 206b, 206c, 206d Laser scanner
207a, 207b, 207c, 207d Laser unit
208a, 208b, 208c, 208d Polygon mirror (Rotating polygon mirror)
220 Paper cassette
221 cassette clutch
222 Feed roller
223 Paper detection sensor
224 resist shutter
225 Suction roller
230 Bypass tray
231 Manual feed clutch
322 Manual feed roller
250 Paper conveyor belt
251 to 254 Rotating roller
260 Fuser
261 Transport roller
262 Output sensor
263 Discharge roller and transport path switching roller for duplex printing
264 Output tray
265 Output load detection sensor
270 Transport path for duplex printing
271 to 274 Double-sided transport rollers
301 Panel I / F section
302 Host I / F section
303 Image data generator
304 ROM
305 Image memory
306 Engine I / F part
307 RAM
308 DMA controller
309 CPU
310 EEPROM
311 hard disk
320 CPU bus

Claims (5)

  A page that analyzes print data based on a plurality of page description languages and generates a drawing object, and in an image forming apparatus capable of processing a plurality of input formats, a page for determining a data format from a data format specification for each page Format determination means, first attribute information definition means for changing the definition of attribute information for each page in accordance with the input drawing command and input data format, and raster generation means for generating a raster image from the input drawing command And attribute information adding means for generating and adding attribute information for each pixel of the raster image according to the drawing command and the input data format, and image processing according to the attribute information definition defined by the first attribute information defining means Image processing method determining means for determining a method, and said image processing method An image forming apparatus, comprising an image processing means for performing image processing determined by the constant section.   The data format determined by the page format determination means is a color space, and the attribute information area defined for each page based on the result of the input data format determination is “whether or not gray guarantee is made” or “by the user 2. The image forming apparatus according to claim 1, further comprising means for meaning whether or not color conversion processing is designated.   3. The image forming apparatus according to claim 1, further comprising an automatic page format determination unit that automatically determines a page format type from input data.   An image forming apparatus that generates print objects by analyzing print data based on a plurality of page description languages, and that generates a raster image from input drawing commands in an image forming apparatus capable of processing a plurality of input formats Generating means, block dividing means for dividing the generated raster image into blocks, automatic block format determining means for automatically determining the format of the raster image divided into blocks for each block, and the determined raster image A second attribute information defining means for changing the definition of the attribute information for each block in accordance with the data format, and the attribute information for each pixel in accordance with the attribute information definition defined by the attribute information defining means and the generated raster image Attribute information adding means to generate / add An image processing method determining unit that determines an image processing method according to the attribute information definition defined by the second attribute information defining unit; and an image processing unit that performs the image processing determined by the image processing method determining unit. An image forming apparatus.   The data format determined by the block format determination means is a color space, and the attribute information area defined for each block based on the second attribute information definition means is “Gray guaranteed or not” or “User The image forming apparatus according to claim 3, further comprising means for meaning “whether or not color conversion processing is designated by“? ”.

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