JP2011073259A - Image processing device, color image forming apparatus, image processing method, image processing program and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing device, a color image forming apparatus, an image processing method, an image processing program and a recording medium which can cope with an increase of the number of colors while at suppressing cost and improving processing speed. <P>SOLUTION: A copy machine 1 reads image data of a reference color CMYK from a main memory 6 by DMAC 13C to 13K and outputs it to an engine 8C to 8K through each line FIFO. The image data of a special color Cl is read from the main memory 6 by DMAC for CMYK before reading the image data of reference color CMYK in a first page, and at the read-out interval of the last and succeeding pages of the reference color CMYK in the second page or the succeeding pages, and is written in a page memory 22 by a page memory writing control part 21, and read by a page memory reading control part 23, and then the image data of the special color Cl are outputted to the engine 8Cl. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image processing device, a color image forming apparatus, an image processing method, an image processing program, and a recording medium, and more specifically, an image processing device corresponding to an increase in the number of colors while suppressing cost and maintaining processing speed. The present invention relates to a color image forming apparatus, an image processing method, an image processing program, and a recording medium.

  In recent years, image forming apparatuses such as copying apparatuses and composite apparatuses are equipped with an integrated circuit for image processing, for example, an ASIC (Application Specific Integrated Circuit), and image data for printing, for example, C (cyan), M ( After the image data of the reference colors of magenta), Y (yellow), and K (black) are once expanded in the main memory, the image data of each plate (each color) is transferred from the main memory in response to an image request from the engine side. The data is read out by a DMAC (Direct Memory Access Controller) and DMA-transferred to the engine side.

  For example, in the case of the copying apparatus 100 as shown in FIG. 9, the image data of the original read by the scanner 101 is subjected to necessary image processing by the scanner ASIC 102, for example, image processing such as correction of scanner characteristics, and the CMYK for printing. The image data is temporarily stored in the hard disk (HDD) 103, and at a predetermined time, a CPU (Central Processing Unit) 104 reads the image data for each page from the hard disk 103 and develops it in the main memory 105. When there is a print request from the electrophotographic printer 107, the printer ASIC 106 sequentially reads out the image data for one page developed in the main memory 105 in units of lines for each color and transfers the image data to the printer 107 as a video signal. . The printer 107 includes a paper feed unit, an image forming unit, a fixing unit, a paper discharge unit, and the like. The image forming unit is required to form an image by the electrophotographic method around the photoconductors 107Ca, 107Ma, 107Ya, and 107Ka for each of the four-color engines 107C, 107M, 107Y, and 107K as reference colors. A charging unit, an optical writing unit, a developing unit, a transfer unit, a charge eliminating unit, a cleaning unit, and the like are arranged, and laser light for each color modulated based on the video signal of each color transmitted from the plotter ASIC 106 is optically written. The electrostatic latent images are formed by irradiating the corresponding color photoconductors 107Ca, 107Ma, 107Ya, and 107Ka. The printer 107 supplies toner from the developing unit to the photoconductors 107Ca, 107Ma, 107Ya, and 107Ka on which the electrostatic latent images are formed to form toner images, and the toner images on the photoconductors 107Ca, 107Ma, 107Ya, and 107Ka are formed. Are sequentially superimposed and transferred onto the sheet 108 conveyed from the sheet feeding unit at the same timing, thereby forming a color image on the sheet 108. By heating and pressurizing the paper 108 onto which the color toner image has been transferred by the fixing unit, the color toner image is fixed on the paper 108 to form an image.

  As shown in FIG. 10, the printer ASIC 106 includes a PCIe ENDP (end point) 111, an arbiter 112, DMACs 113C, 113M, 113Y, 113K, line FIFOs 114C, 114M, 114Y, 114K and video corresponding to the image data of each color. IF115C, 115M, 115Y, and 115K are installed. The PCIe ENDP 111 separates a request and a response, and the main component via the CPU 104 is a PCI (Peripheral Component Interconnect) Express (hereinafter referred to as PCIe) that is a high-speed split transaction bus that can issue a next request without waiting for a response. It is connected to the memory 105, and exchanges data and commands with the main memory 105.

  The DMACs 113C, 113M, 113Y, and 113K are connected to the PCIe ENDP 111 via the arbiter 112, and when activated by the CPU 104, image data of corresponding colors are respectively received from the main memory 105 via the arbiter 112 and the PCIe ENDP 111. Read and pass to line FIFOs 114C, 114M, 114Y, 114K. The arbiter 112 arbitrates bus use requests from the DMACs 113C, 113M, 113Y, and 113K. When there is a transfer request from the printer 107, the line FIFOs 114C, 114M, 114Y, and 114K immediately transfer the stored image data to the printer 107.

  In this case, the physical positional relationship between the photoreceptors 107Ca, 107Ma, 107Ya, and 107Ka of the engines 107C, 107M, 107Y, and 107K of the printer 107 and the transfer timing of the image data from the engine ASIC 106 are shown in FIG. The station intervals (station pitch) of the photoconductors 107Ca, 107Ma, 107Ya, 107Ka and the video signals c, m, y, k of the respective colors are changed from the engine ASIC 106 to the engines 107C, 107M, 107Y, 107K of the printer 107. The timing to be transferred to is determined.

  The printer ASIC 106 transfers the video signals c, m, y, and k for each of the photoconductors 107Ca, 107Ma, 107Ya, and 107Ka in accordance with the conveyance of the paper 108 to form an electrostatic latent image. In response to the image request, image data of each plate (each color) is read from the main memory 105 by the DMACs 113C, 113M, 113Y, and 113K, and is output to the printer 107 side. At this time, the DMACs 113C, 113M, 113Y, and 113K read image data from the main memory 105 by burst transfer via the PCIe ENDP 111 and PCIe, but transfer of other versions of the DMACs 113C, 113M, 113Y, and 113K occurs simultaneously. In this case, the arbiter 112 arbitrates within the printer ASIC 106, and the bandwidth of the PCIe is shared by a plurality of DMACs 113C, 113M, 113Y, and 113K.

  If the DMA transfer of each plate is not in time for the image request from the printer 107, that is, if the requested data transfer rate is too high and exceeds the bandwidth that PCIe can provide, the printer 107 As shown in FIG. 12, the writing speed that does not become an abnormal image so as not to exceed the limit band of PCIe for the transfer of the video signal on the engine side as shown in FIG. Alternatively, the bandwidth setting of PCIe is important.

  On the other hand, in recent years, in addition to reference color (4 colors, etc.) toner (developer), special color toners, such as transparent toner and white toner, are added to form an image with a reference color or higher (5 colors or more) toner. Therefore, a transparent company logo is added, or a full-scale coating is applied to give a gloss.

  However, as the number of colors increases, the amount of image data transferred increases by the increased colors. For example, as shown in FIG. 13, when the printer 107 has four colors (CMYK) reference color and special color Cl, the photosensitive members are photosensitive members 107Ca, 107Ma, 107Ya, and 107Ka. The printer ASIC 121 needs to read out the image data Cl for the increased photoconductor Cl from the main memory 105 and transfer it to the printer 107 as well.

  When the conventional image transfer method for four colors is applied to image transfer of five colors as it is, as shown in FIG. 14, the printer ASIC 121 corresponding to five colors has an increased color DMAC 113Cl, line FIFO 114Cl, video IF 115Cl. Is a circuit configuration connected to the arbiter 112.

  In this case, if the DMA transfer of the image data by each version of the DMAC 113C to 113Cl is not in time for the image request from the printer 107 side, that is, the requested data transfer rate is too high, as shown in FIG. If the bandwidth exceeds the bandwidth that can be provided by PCIe, the image data may not be in time for the paper transfer timing, and an abnormal image such as color misregistration may occur. Therefore, it is important to set a writing speed that does not cause an abnormal image or a bandwidth setting of PCIe.

  Conventionally, a technique has been proposed in which a developing means for transparent toner in addition to CMYK colors has been formed, and the developing means based on the transparent toner forms a transparent toner image by using an inverted signal of one of the CMYK colors. (See Patent Document 1). That is, in this prior art, an image of a transparent toner other than the reference color such as CMYK is formed by an inverted signal of the image data of the reference color.

  However, in the prior art described in the above publication, the transparent toner image is formed by the inverted signal of the image data other than the reference color. In any case, the image other than the reference color is developed to form an image. As shown in FIG. 13, the image forming unit such as a photosensitive member is transferred from the main memory 105 to the printer 107 via the engine ASIC 121 to transfer image data of a color other than the reference color (transparent color, etc.) Cl. Therefore, it is necessary to increase the DMAC 113Cl for transferring the image data from the main memory 105 by one as the development unit is increased by one.

  As a result, in an image forming apparatus to which an image forming unit of increased color (plate) is added, in order to perform image formation at the same speed as color image generation when only the reference color is used, an image required from the engine When the transfer rate exceeds the limit value of the PCIe band, the transfer of the video signal from the printer ASIC to the engine is broken, resulting in an abnormal image. Therefore, the PCIe is changed to an expensive and high-performance PCIe bus to increase the limit value of the PCIe band, or the image forming speed is reduced according to the limit value of the PCIe band without changing the PCIe bus (production). Etc.), and there is a problem that the cost increases or the processing speed decreases.

  Therefore, the present invention improves the image quality of the formed image while suppressing the cost and transferring the image data of a larger number of colors more quickly and improving the processing speed at a low cost even if the number of colors increases. An object of the present invention is to provide an image processing device, a color image forming apparatus, an image processing method, an image processing program, and a recording medium.

  In order to achieve the above object, the present invention reads the reference color image data from the memory, temporarily stores the reference color image data in the line memories corresponding to the number of reference colors, and sets the reference data of each line memory. The color image data is output to the corresponding color image forming unit in accordance with the image forming timing of the image forming unit, and the special color image data different from the reference color is read out and written in the page memory. When the image data of the special color in the page memory is read out and output to the image forming unit in accordance with the image forming timing of the image forming unit corresponding to the special color, the reference color The special color image data is read from the memory and written to the page memory before reading the image data of the second page. In this case, the image data of the special color of the next page is sequentially read from the memory by a predetermined data amount and written to the page memory at the interval of reading the image data of the previous page and the next page of the reference color. .

  Further, according to the present invention, in the transfer of the special color image data from the second page onward, if the special color image data of the previous page and the next page are image data having the same content, the special color from the memory The image data of the previous page stored in the page memory as the special color image data of the next page may be read out.

  Further, according to the present invention, when the image data to be output from the memory to the image forming unit is image data of only the reference color, the page memory is switched as an expansion memory for expanding the line memory of each reference color. It may be characterized by being used.

  According to the present invention, it is possible to more quickly transfer image data of a larger number of colors while suppressing cost, and even if the number of colors increases, the image quality of the formed image is improved while reducing the processing speed. Can be improved.

1 is a schematic configuration diagram of a five-color copying apparatus to which an embodiment of the present invention is applied. FIG. 3 is a circuit block diagram of a printer ASIC. The figure which shows the utilization condition of the timing at the time of transferring the image data of the 1st page of 5 colors before the image data transfer of other 4 colors. The figure which shows the timing at the time of transferring the image data after the 2nd page of a 5th color between the papers of the image data of another 4 colors, and the utilization condition of a PCIe band. The figure which shows the utilization condition of the timing at the time of transferring the image data of 5th color by DMAC for all colors before image data transfer of other 4 colors. 7 is a flowchart illustrating special color image data transfer control processing. Explanatory drawing of the utilization aspect of the page memory at the time of duplex printing. The circuit block block diagram of printer ASIC in the case of applying for wide width. 1 is a schematic configuration diagram of a four-color copier. FIG. 3 is a block diagram of the main part of a four-color printer ASIC. The figure which shows the arrangement | positioning relationship of a photoconductor in the case of 4 colors, and the transfer timing of a video signal. The figure which shows the utilization condition of the PCIe zone | band in the data transfer of 4 colors, and an engine side video signal transfer condition. The figure which shows the arrangement | positioning relationship of a photoconductor in the case of 5 colors, and the transfer timing of a video signal. FIG. 6 is a circuit block diagram of a conventional five-color printer ASIC. Explanatory drawing in case utilization of a PCIe band exceeds a limit value by increasing one color at the video signal transfer timing of four colors.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, since the Example described below is a suitable Example of this invention, various technically preferable restrictions are attached | subjected, However, The range of this invention is unduly limited by the following description. However, not all the configurations described in the present embodiment are essential constituent elements of the present invention.

  1 to 8 are diagrams showing an embodiment of an image processing device, a color image forming apparatus, an image processing method, an image processing program, and a recording medium according to the present invention, and FIG. 1 is a schematic configuration diagram of a main part of a copying apparatus 1 to which an embodiment of a color image forming apparatus, an image processing method, an image processing program, and a recording medium is applied.

  In FIG. 1, a copying apparatus 1 includes a scanner 2, a scanner ASIC 3, a hard disk (HDD) 4, a CPU 5, a main memory 6, a printer ASIC 7, a printer 8, and the like. This is a copying apparatus 1 corresponding to image formation.

  For example, a line image sensor using a CCD (Charge Coupled Device) or the like is used as the scanner 2 and generally includes an ADF. A plurality of documents are set in the ADF, and the ADF feeds the set documents one by one to the document reading position of the scanner 2. The scanner 2 scans a document conveyed from the ADF, reads an image of the document with a predetermined resolution, performs sampling processing, A / D conversion processing, and the like, and outputs digital image data to the scanner ASIC 3.

  The scanner ASIC 3 performs appropriate image processing on the document image data read by the scanner unit 6 and stores the image data after image processing in the hard disk 4 under the control of the CPU 5.

  The CPU 5 executes basic processing as the copying apparatus 1 based on a program in a ROM (Read Only Memory) (not shown), and produces image data for five colors by the DMAC for four colors according to the present invention. The image forming process is executed to transfer and form an image while maintaining the characteristics.

  That is, the copying apparatus 1 includes a ROM, an EEPROM (Electrically Erasable and Programmable Read Only Memory), an EPROM, a flash memory, a flexible disk, a CD-ROM (Compact Disc Read Only Memory), a CD-RW (Compact Disc Rewritable), a DVD ( The above ROM is read by reading an image forming program for executing the image forming method of the present invention recorded on a computer readable recording medium such as a digital versatile disk (SD), a secure digital (SD) card, or an MO (Magneto-Optical Disc). An image forming method for forming an image by introducing image data corresponding to the number of colors obtained by adding a special color to a reference color, which will be described later, while maintaining the processing speed (productivity) of the copying apparatus 1 by being introduced into the hard disk 4 or the like It is constructed as an image forming apparatus that executes the above. This image forming program is a computer-executable program written in a legacy programming language such as assembler, C, C ++, C #, Java (registered trademark) or an object-oriented programming language, and is stored in the recording medium. Can be distributed.

  The printer 8 records and outputs an image on a sheet by electrophotography based on the image data delivered from the ASIC 4. The printer 8 includes a paper feed unit, an image forming unit, a fixing unit, a paper discharge unit, and the like. The image forming unit includes engines (image forming units) 8C, 8M, 8Y, 8K, and 8Cl for five colors. ing. The paper feed unit separates a plurality of sheets P stored in the paper feed tray one by one and conveys them to the image forming unit.

  The engines 8C, 8M, 8Y, 8K, and 8Cl for each color of the image forming unit are not shown around the photoconductors 8Ca, 8Ma, 8Ya, 8Ka, and 8Cla, but include a charging unit, an optical writing unit, a developing unit, a transfer unit, A static elimination unit, a cleaning unit, and the like are provided. Each color engine 8C, 8M, 8Y, 8K, 8Cl of the image forming unit operates the optical writing unit according to the video signal of the corresponding color, respectively, so that it is statically placed on the photoreceptors 8Ca, 8Ma, 8Ya, 8Ka, 8Cla. An electrostatic latent image is formed, and development is performed by supplying toner onto the photoreceptors 8Ca, 8Ma, 8Ya, 8Ka, and 8Cla by the developing unit to form a toner image. The engines 8C, 8M, 8Y, 8K, and 8Cl for each color are fed to a sheet (image forming medium) P that is conveyed from the paper feeding unit between the photoreceptors 8Ca, 8Ma, 8Ya, 8Ka, and 8Cla and the transfer unit. The toner images of the respective colors on the photoconductors 8Ca, 8Ma, 8Ya, 8Ka, and 8Cla are sequentially superimposed and transferred, and the color toner image is transferred to the paper P. The printer 8 conveys the paper P to which the color toner image has been transferred to the fixing unit, and heats and presses the paper P to fix the color toner image on the paper P to form an image.

  The CPU 5 reads out image data for each page from the hard disk 4 at a predetermined printing timing, develops it in the main memory 6, and writes a descriptor necessary for DMA transfer of the image data to the printer ASIC 7 in the main memory 6.

  As shown in FIG. 2, the printer ASIC (image processing device) 7 includes a PCIe ENDP (end point) 11, an arbiter 12, DMACs 13C, 13M, 13Y, and 13K corresponding to the image data of the reference colors, and for the reference colors Line memory 14C, 14M, 14Y, 14K, video IF 15C, 15M, 15Y, 15K, 15Cl and page memory write control connected between each DMAC 13C, 13M, 13Y, 13K and video IF 15C, 15M, 15Y, 15K, 15Cl A unit 21, a Cl color page memory 22, a page memory read control unit 23, and a resolution / gradation conversion unit 24 are mounted.

  The PCIe ENDP 11 is connected to the main memory 6 via the CPU 5 by the PCIe, and exchanges data and commands with the main memory 6.

  The PCIe ENDP 11 is connected to the DMACs 13C, 13M, 13Y, and 13K via the arbiter 12, and the arbiter 12 arbitrates bus use requests from the DMACs 13C, 13M, 13Y, and 13K.

  The DMACs (data reading means) 13C, 13M, 13Y, and 13K receive image data for one page of each color developed in the main memory 6 based on the descriptor of the main memory 6 via the arbiter 12 and the PCIe ENDP 11. For each line, the data is read out and written to the corresponding line FIFOs 14C, 14M, 14Y, and 14K, and also transferred to the page memory write control unit 21.

  When there is a transfer request from the engines 8C, 8M, 8Y, and 8K, the line FIFO (line memory) 14C, 14M, 14Y, and 14K immediately transfer the stored image data to the engines 8C, 8M, 8Y, and 8K. .

  The page memory write control unit (write control means) 21 receives the image data of the special color Cl read from the main memory 6 by the DMACs 13C, 13M, 13Y, and 13K, and writes it in the Cl page memory 22.

  The Cl page memory (page memory) 22 includes page memories 22C, 22M, 22Y, and 22K corresponding to the DMACs 13C, 13M, 13Y, and 13K. The memory size is determined by the resolution, gradation, size, and the like of the fifth color of the Cl color. For example, when the size is A4 size, the resolution is 200 dpi, and the gradation is 1 bit, the memory capacity is 3.6 Mbit. Further, if the size is A3, the resolution is 200 dpi, and the gradation is 1 bit, the memory capacity is 7.3 Mbit. With such a memory capacity, both are memory capacity that can be built into an existing ASIC. Note that the fifth page memory 22 is not limited to the one built in the printer ASIC 7, but is built into the printer ASIC 7 when the capacity becomes large, for example, when several A3 pages are required. It is good also as external memory, without doing.

  When there is a transfer request for image data from the engine 8Cl, the page memory read control unit (page memory read control means) 23 sequentially reads line data from the Cl page memory 22 and sends it to the resolution / gradation conversion unit 24. The gradation converter 24 converts the image data received from the page memory read controller 23 into the resolution and gradation required by the engine 8Cl, and outputs the converted video data to the engine 8Cl.

  Next, the operation of this embodiment will be described. The copying apparatus 1 of this embodiment forms an image by transferring image data at a low speed and at a high speed even when the number of special colors added to the reference color increases.

  That is, the copying apparatus 1 performs necessary image processing on the original image data read by the scanner 2 by the scanner ASIC 3 and temporarily stores it as CMYK image data for printing in the hard disk (HDD) 4 at a predetermined time. In addition, the CPU 5 reads the image data for each page from the hard disk 4 and develops it in the main memory 6. When there is a print request from the electrophotographic printer 8, the printer ASIC 7 sequentially reads out image data for one page developed in the main memory 6 for each color in units of lines and transfers the image data to the printer 8 as a video signal. .

  That is, the printer ASIC 7 activates the reference color CMYK image data from the main memory 6 via the arbiter 12 and the PCIe ENDP 11 by the DMACs 13C, 13M, 13Y, and 13K when the CPU 5 is activated. Color) image data is read out and stored in the line FIFOs 14C, 14M, 14Y and 14K. When there is a transfer request of image data from the engines 8C, 8M, 8Y and 8K, the image data is stored in the line FIFOs 14C, 14M, 14Y and 14K. The image data of the reference colors CMYK is transferred to the corresponding engines 8C, 8M, 8Y, 8K of the printer 8.

  For the special color Cl image data, the printer ASIC 7 uses the DMAC 13C, 13M, 13Y, and 13K to transfer the image data of the reference color CMYK of the first page to the main memory 6 for the special color Cl of the first page. 3, any one of the CMYK DMAs 13C, 13M, 13Y, and 13K is activated to read out image data of a special color Cl such as transparent toner previously drawn in the main memory 6, as shown in FIG. The page memory write control unit 21 stores the data in the page memory 22.

  When the transfer of the special color Cl image data to the page memory 22 is completed, the printer ASIC 7 starts the transfer of the image data of the first page of the reference color CMYK by the DMACs 13C, 13M, 13Y, and 13K as described above. In transferring the reference color CMYK image data, the DMACs 13C, 13M, 13Y, and 13K corresponding to the CMYK colors are sequentially activated to transfer the image data of each color. Since the transfer to the memory 22 is completed and stored, image data of only the reference color CMYK flows as the PCIe band.

  For the second and subsequent pages, as shown in FIG. 4, the printer ASIC 7 starts after the image data transfer of the reference color CMYK of the previous page and before the start of image data transfer of the reference color CMYK of the next page. The image data of the next page of the special color Cl is read from the main memory 6 by the DMACs 13C, 13M, 13Y, and 13K and written to the page memory 22. For example, in the case of the C-color DMAC 13C, when the C-color image data transfer for the first page is completed, the transfer of the special color Cl for the next page is requested before the engine 8C requests the transfer of the C-color image data for the second page. Image data (in this case, sub-scan 4 divisions) is read from the main memory 6 and written to the page memory 22. Thereafter, the DMAC 13C reads out the C-color image data of the second page from the main memory 6 and transfers it to the line FIFO 14C. Similarly, the MYK color DMACs 13M, 13Y, and 13K operate in the same manner as in the case of the C color, and conventionally, the DMACs 13C, 13M, 13Y, and 13K are not used between pages. During the period, the DMACs 13C, 13M, 13Y, and 13K can be used to transfer the image data of the special color Cl, and the image data of the special color Cl can be transferred without overlapping the transfer of the image data of all other colors. .

  Therefore, the five colors including the special color Cl are included in the reference color CMYK without breaking the PCIe band, without increasing the DMACs 13C, 13M, 13Y, and 13K, and without increasing the transfer interval of the paper P in the printer 8. Image data can be transferred, and the image quality of the formed image can be improved at low cost and with improved processing speed. Further, productivity can be maintained even in continuous page printing while preventing the PCIe band from being broken without replacing the PCIe with an expensive one having a high band.

  As described above, the copying apparatus 1 according to the present embodiment reads image data of the reference color CMYK from the main memory 6 and sets the reference colors CMYK to the line FIFOs 14C, 14M, 14Y, and 14K corresponding to the number of reference colors. The image data of each of the line FIFOs 14C, 14M, 14Y, and 14K is temporarily stored, and the image data of the reference colors CMYK of the respective line FIFOs 14C, 14M, 14Y, and 14K is stored in the engines 8C, 8M, 8Y, and 8K of the corresponding colors. In addition to outputting in accordance with the image formation timing, the image data of the special color Cl is read out from the main memory 6 and written in the page memory 22, and the special data in the page memory 22 is adjusted in accordance with the image formation timing of the engine 8Cl corresponding to the special color Cl. When the image data of the color Cl is read and output to the engine 8Cl, the special color Cl of the first page For image data, the image data of the special color Cl is read from the main memory 6 and written to the page memory 22 before the image data of the reference color CMYK is read. The image data of the special color Cl of the next page is sequentially read from the main memory 6 by a predetermined data amount and written to the page memory 22 at the reading interval of the image data of the previous page and the next page of the color CMYK.

  Therefore, when transferring a color image of the number of colors (for example, 5 colors) obtained by adding the special color Cl to the reference color CMYK from the main memory 6 to the engines 8C, 8M, 8Y, 8K, 8Cl, the DMACs 13C, 13M, 13Y are also used. , 13K, and before transferring the image data of the reference color CMYK of the first page and between the pages, the image data of the special color Cl can be transferred to improve the transfer speed of the image data. It is possible to improve the image quality of the formed image while improving the processing speed at a low cost by transferring the image data of a larger number of colors more quickly while suppressing the cost. That is, after storing the image data of the special color Cl for one page in the page memory 22 between the papers during the data transfer of the reference colors CMYK so that the image transfers of the five color image data do not overlap, Output in accordance with the transfer of the color CMYK image data, it is possible to form an image at the same processing speed (productivity) as when generating a four-color image even when generating a five-color image.

  In the above description, the image data of the special color Cl of the first page is transferred from the main memory 6 to the page memory 22 using any of the DMACs 13C, 13M, 13Y, and 13K of the reference colors CMYK. However, the transfer of the image data of the special color Cl of the first page from the main memory 6 to the page memory 22 is not limited to the above method. For example, as shown in FIG. 5, all DMACs 13C, 13M, 13Y, 13K may be used at the same time to transfer the image data of the special color Cl from the main memory 6 to the page memory 22.

  In this way, the image of the special color Cl can be obtained in a shorter time than when the image data of the special color Cl is transmitted from the main memory 6 to the page memory 22 using any one of the DMACs 13C, 13M, 13Y, and 13K. Data can be transferred.

  Further, in the above description, when forming images of a plurality of pages, if the image data of the fifth special color Cl is the same between consecutive pages, as shown in FIG. 6 for the C color (plate), the same special The transfer of the image data of the color Cl may be omitted.

  That is, when the C color (plate) DMAC 13C starts to transfer the previous page C color (plate) image data from the main memory 6 to the page memory 22 (step S201), the C color (plate) image data Is completed (step S202), and it is checked whether the image data of the special color Cl of the next page is the same as the image data of the special color Cl of the previous page (step S203).

  In step S203, when the image data of the special color Cl for the previous page and the next page is the same, the DMAC 13C does not transmit the image data of the special color Cl from the main memory 6 to the page memory 22, but the next C color (version). Is transferred from the main memory 6 to the line FIFO 14C (step S204).

  In step S203, when the image data of the special color Cl for the previous page and the next page are different, the DMAC 13C for C color (plate) transmits the image data of the special color Cl for the next page from the main memory 6 to the page memory 22. (Step S205) Waiting for the transfer of the image data of the special color Cl from the main memory 6 to the page memory 22 (Step S206), the C color (plate) image data of the next page is stored in the main memory 6 To the line FIFO 14C (step S204).

  The copying apparatus 1 also uses the main memory for the image data of the special color Cl when the image data of the special color Cl is the same for the previous page and the next page for the ASICs 13M, 13Y, and 13K for the other colors as well as the ASIC 13C for the C color. 6 is omitted, and image data of the corresponding color (M, Y, K color) of the next page is transferred from the main memory 6 to the page memory 22.

  As such, when the image data of the special color Cl, for example, the transparent color is the same in continuous pages, when the entire image is coated with a transparent toner or when the same company logo is printed on all pages with the transparent toner, etc. Transfer of image data of special color Cl between papers can be omitted, and the paper space can be reduced to further improve productivity, and a special paper width (a wide paper size such as A2 to A0). ) Can be dealt with appropriately.

  Furthermore, the multifunction apparatus 1 according to the present exemplary embodiment includes a double-sided printing function in which the printer ASIC 7 has a memory capacity corresponding to, for example, A3 size as the page memory 22 and continuously prints on the front and back surfaces. If the data content of the special color Cl is different between the front and back during duplex printing, the A3 size memory capacity is divided into two A4 sizes for the front and back as shown in FIG. The A4 size special color Cl front image data and back image data are stored separately. For example, when the company logo is arranged on the left and right edges on a spread page, the image data of the company logo formed by the image data of the transparent color Cl will be at different positions on the front and back surfaces, so different image data It becomes. In such a case, the printer ASIC 7 divides the page memory 22 into, for example, two A4 size planes, and the DMACs 13C, 13M, 13Y, and 13K read from the page memory 22 in response to a request from the engine 8Cl. The page memory write control unit 21 determines whether the image data of the special color Cl is the front side image data or the back side image data, and distributes and stores the image data for the front side and the back side of the page memory 22. . The page memory write control unit 21 determines whether the image data of the special color Cl sent from the DMACs 13C, 13M, 13Y, and 13K is image data for the front side or image data for the back side. It may be determined by a signal input from 13K (indicated by a register or descriptor for DMACs 13C, 13M, 13Y, and 13K), or may be determined by a register value set in a register or the like.

  In the printer ASIC 7, the page memory read control unit 24 reads the image data for the front surface and the image data for the back surface of the special color Cl in response to a request from the engine 8Cl, and the resolution / tone conversion unit 24 appropriately Resolution / gradation conversion is performed and output to the engine 7Cl.

  Even in this case, when the size of the image data to be printed is A3 size, as described above, the page memory 22 is used as the page memory for one page, and the image data of the special color Cl is transferred. To use.

  In this way, it is not necessary to transfer the image data of the special color Cl between the front and back sheets during double-sided printing, and the processing speed (productivity) can be improved.

  Further, when the copying apparatus 1 performs printing on a wide sheet P of A2 size or larger, the composite apparatus 1 of the present embodiment displays video output lines FIFO 14C, 14M, 14Y, and 14K on the wide sheet. It is necessary to increase the size of P.

  Therefore, when printing on a wide sheet P of four colors, the page memory 22 may be used as a line memory for expanding the line FIFOs 14C, 14M, 14Y, and 14K, as shown in FIG.

  In this case, for example, it is necessary to switch the page memory 22 between the page memory for the special color Cl and the four-color extended line memory in the case of five-color printing and the case of four-color printing. When (Static RAM) is used, the connection of the page memories 22C, 22M, 22Y, and 22K is switched by a register or the like, thereby connecting as an extended line memory of the line FIFOs 114C, 114M, 114Y, and 114K, or connecting as the page memory 22 I will respond.

  In this case, for example, the printer ASIC 7 can be applied to both the five-color image forming apparatus and the four-color image forming apparatus, so that versatility can be improved and processing in four colors can be performed. Speed can be improved.

  Although not shown, the page memory 22 may be used as an extended line memory for the reference color when printing four or less reference colors.

  In this case as well, when the page memory 22 is configured by SRAM, the Cl page memories 22C, 22M, 22Y, and 22K can be switched by using a register or the like to switch the connection between four colors or less and five colors. To do.

  That is, normally, the line FIFOs 14C, 14M, 14Y, and 14K are provided for quickly outputting image data in response to a data transfer request from the engines 8C, 8M, 8Y, and 8K. The DMACs 13C, 13M, 13Y, and 13K need to fill the line FIFOs 14C, 14M, 14Y, and 14K during the image data transfer of the DMACs 13C, 13M, 13Y, and 13K. , 13M, 13Y, 13K, etc., the transfer rate may temporarily drop, so the printing speed specification is usually provided with a margin.

  However, as described above, when the page memory 22 is used as an expansion line FIFO for the line FIFOs 114C, 114M, 114Y, and 114K, as a whole, the same result as when the number of the line FIFOs 14C, 14M, 14Y, and 14K for each color is increased. Therefore, even if the processing speed of the engines 8C, 8M, 8Y, and 8K is increased and the transfer rate of the DMACs 13C, 13M, 13Y, and 13K is temporarily reduced, the transfer can be prevented from failing. High-speed printing can be expected by cutting the margin.

  In the above description, the case where there are four reference colors and one special color has been mainly described. However, the reference colors and special colors are not limited to the number of colors described above, and the reference colors are four colors. The above or four colors or less can be applied in the same manner, and even if the special color is two or more colors, the same can be applied.

  Although the invention made by the present inventor has been specifically described based on the preferred embodiments, the present invention is not limited to that described in the above embodiments, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

  The present invention relates to an image processing device that can be shared by color image forming apparatuses having different numbers of colors, a color image forming apparatus having the image processing devices mounted thereon, and an image processing in which the image processing devices are shared by different color image forming apparatuses. It can be used for a method, an image processing program, and a recording medium.

1 Copier 2 Scanner 3 Scanner ASIC
4 Hard disk (HDD)
5 CPU
6 Main memory 7 Printer ASIC
8 Printer 8C, 8M, 8Y, 8K, 8Cl Engine 8Ca, 8Ma, 8Ya, 8Ka, 8Cla Photoreceptor 11 PCIe ENDP
12 Arbiter 13C, 13M, 13Y, 13K DMAC
14C, 14M, 14Y, 14K line FIFO
15C, 15M, 15Y, 15K, 15Cl Video IF
21 Page memory write control unit 22 Cl color page memory 23 Page memory read control unit 24 Resolution / tone conversion unit

Japanese Patent Laid-Open No. 9-200551

Claims (10)

Image processing for sequentially reading out and outputting the image data of each color on the memory to the image forming means for each color that forms the image of the color on the image forming medium based on the image data of the predetermined number of colors. A device,
Of the image data of each color on the memory, the number of reference colors smaller than the maximum number of the predetermined number of colors is provided, the corresponding image data of the reference color is read out, and is different from the reference color Data reading means for reading out image data of special colors of a predetermined number of colors;
Line memories corresponding to the number of reference colors for temporarily storing image data of the reference colors read by the data reading means,
Data output means for outputting the image data of the reference color of each line memory to the image forming means of the corresponding color in accordance with the image forming timing of the image forming means;
A predetermined number of page memories for storing image data for one page formed on the image forming medium;
Write control means for writing the image data of the special color read by the data reading means into the page memory;
Page memory read control means for reading out the image data of the special color in the page memory and outputting it to the image forming means corresponding to the special color in accordance with the image formation timing of the image forming means;
For the image data of the first page, before reading the image data of the reference color, the image data of the special color is read from the memory by the data reading unit, and the writing control unit is written to the page memory, For the image data of the second and subsequent pages, the special color image data of the next page is stored in each data reading unit at the reading interval of the image data of the previous page and the next page of the reference color by each data reading unit. Special color data control means for sequentially reading a predetermined amount of data from the memory and causing the write control means to write to the page memory;
An image processing device comprising:   The image processing device according to claim 1, wherein the special color data control unit causes the special color image data of the first page to be read simultaneously by all the data reading units.   The special color data control means determines that when the special color image data on the second and subsequent pages is the same color image data on the previous page and the next page, the data reading means Reading of the special color image data from the memory is stopped, and the page memory read control means reads the image data of the previous page stored in the page memory as the special color image data of the next page. The image processing device according to claim 1, wherein the image processing device is output.   The special color data control means has a capacity for storing the image data of the special color of two or more pages formed on the image forming medium by the image forming means in the page memory. The memory is divided into a front page memory and a back page memory, and before transferring the reference color image data of the first page, the special color front and back image data is transferred from the memory to the data reading means. Is read out and written to the page memory for the front side and the page memory for the back side of the page memory, and the subsequent special color image data is read from the page memory by the page memory read control unit. The image data of the front or back surface corresponding to the output front page memory or back page memory is output from the memory to the data. The image processing device according to any one of claims 1 to 3, characterized in that for writing into the page memory or the back pages memory for surface to said write control means to read the reading means.   The special color data control means expands the page memory to the line memory for each of the reference colors when the image data to be output from the memory to the image forming means is image data of only the reference colors. The image processing device according to claim 1, wherein the image processing device is switched and used as the image processing device. The image processing device includes conversion means for decompressing image data whose resolution and gradation are compressed by a predetermined compression method,
The special color image data is stored in the memory in a state compressed by the compression method,
2. The conversion unit according to claim 1, wherein the conversion unit decompresses the compressed special color image data read from the page memory by the page memory read control unit and outputs the decompressed image data to the data output unit. The image processing device according to claim 5. A plurality of image forming means for forming images of different colors on the image forming medium to be conveyed; the image processing device reads image data of a predetermined number of colors in the memory; In a color image forming apparatus that outputs and forms a color image by sequentially forming an image of the color on an image forming medium by the image forming unit,
A color image forming apparatus comprising the image processing device according to claim 1 as the image processing device. Image processing for sequentially reading out and outputting the image data of each color on the memory to the image forming means for each color that forms the image of the color on the image forming medium based on the image data of the predetermined number of colors. A method,
Among the image data of each color on the memory, the number of processing steps is the same as the number of reference colors less than the maximum number of the predetermined number of colors, and the corresponding image data of the reference color is read, A data read processing step for reading out image data of a special color having a predetermined number of colors different from the reference color;
Temporary storage control processing step of temporarily storing the image data of the reference color number read in the data read processing step in the line memory for the reference color number;
A data output processing step of outputting the image data of the reference color of each line memory to the image forming unit of the corresponding color in accordance with the image forming timing of the image forming unit;
A write control processing step of writing the special color image data read in the data read processing step into one page memory of a predetermined number of page memories;
A page memory read control processing step of reading out the image data of the special color in the page memory and outputting the image data to the image forming unit corresponding to the special color in accordance with the image forming timing of the image forming unit;
For the image data of the first page, the special color image data is read from the memory by the data read processing step before the reference color image data is read, and is written to the page memory by the write control processing step. For the image data of the second and subsequent pages, the special color of the next page is read by each data read processing step at the interval of reading the image data of the previous page and the next page of the reference color by each data read processing step. Special color data control processing step of sequentially reading out a predetermined amount of data from the memory and writing to the page memory in the write control processing step;
An image processing method characterized by comprising: Image processing for sequentially reading out and outputting the image data of each color on the memory to the image forming means for each color that forms the image of the color on the image forming medium based on the image data of the predetermined number of colors. A program,
On the computer,
Among the image data of each color on the memory, the number of processing is the number of reference colors smaller than the maximum number of the predetermined number of colors, and the corresponding reference color image data is read and the reference data A data read process for reading out image data of a special color having a predetermined number of colors different from the color;
A temporary storage control process for temporarily storing the image data of the reference color number read in the data read process in the line memory for the reference color number;
A data output process for outputting the image data of the reference color of each line memory to the image forming unit of the corresponding color in accordance with the image forming timing of the image forming unit;
A write control process for writing the image data of the special color read in the data read process into one page memory of a predetermined number of page memories;
A page memory read control process for reading out the image data of the special color in the page memory and outputting it to the image forming unit corresponding to the special color in accordance with the image formation timing of the image forming unit;
For the image data of the first page, the image data of the special color is read from the memory by the data read process before the image data of the reference color is read, and written to the page memory by the write control process, For the image data of the second and subsequent pages, the image data of the special color of the next page is read by the data read process at the read interval of the image data of the previous page and the next page of the reference color by the data read process. A special color data control process in which a predetermined amount of data is sequentially read from the memory and written to the page memory by the write control process;
An image processing program for executing   A computer-readable recording medium on which the image processing program according to claim 9 is recorded.

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