JP2009269311A - Image forming apparatus and image data transfer method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform a highly reliable image data transfer by an inexpensive structure without preparing a cost accumulating serial data transfer means of a plurality of channels and page memory in a printer engine part by efficiently utilizing the serial data transfer means. <P>SOLUTION: The transfer of image data of every color is controlled by a multiplexer part 23 by utilizing a serial data transfer means 2 in time sharing in every color at the transfer of image data of every color stored in the FIFO 19, 20, 21 and 22 of a controller part 1 to the printer engine part 3. Further, an image forming apparatus has a configuration that the priority order of every color at the utilization of the serial data transfer means 2 is decided based on the color order in the formation of an image and the transferred data amount of the image data in every color. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to serial data transfer processing of image data in an image forming apparatus.

  FIG. 6 is a diagram illustrating the configuration of a general printer.

  As shown in FIG. 6, a page printer 301 as an image printing apparatus is connected to a host computer 302 having a printer driver 302a via a communication medium 303 such as a network or a USB interface. The page printer 301 includes a controller unit 301a and a printer engine unit 301b.

  The controller unit 301a converts intermediate output data generated from printing source data by a device such as the host computer 302 into output image data suitable for output. The printer engine unit 301b acquires the output image data output from the controller unit 301a, and outputs the image to a medium such as paper.

  Generation of intermediate output data suitable for the controller unit 301a is generally performed by software called a printer driver (printer driver 302a). Further, the controller unit 301a converts the intermediate output data into output image data suitable for the printer engine unit 301b, and outputs it as a video signal to the printer engine unit 301b in synchronization with the image transfer permission signal from the printer engine unit 301b.

  The printer engine unit 301b controls and drives the electrophotographic process, and outputs the input video signal as an image on a medium such as paper.

[Inline method]
For electrophotographic process type color printers, a high-speed printing method based on parallel processing called an inline method has been proposed and put into practical use.

  In the in-line method, the photosensitive drums for four colors are arranged in a line, and the printing process for each color is overlapped to shorten the printing time.

  Hereinafter, image timing supplied to the inline color laser printer will be described with reference to FIG.

  FIG. 7 is a timing chart showing the output data output timing of the inline method.

  In FIG. 7, a is a page synchronization signal, and b to e are print data transfer timings.

  As is apparent from FIG. 7, in the inline type electrophotographic printer, it is necessary to transfer the print data of each color almost simultaneously in synchronization with the page synchronization signal.

  FIG. 8 is a block diagram showing a controller configuration of a general inline printer.

  As shown in FIG. 8, the controller of the inline printer includes a CPU 201 connected to a system bus 207, a ROM 202, an external I / F unit 203, a 4-channel DMAC 204, a page memory 205, an image data output unit 260, and the like. . Further, the image data output unit 260 is connected to the printer engine unit 280.

  The intermediate output data generated by the host computer is received by the external I / F unit 203, converted into compressed data that can be hardware processed by the CPU 201, and then stored in the page memory 205. When storage of the compressed data necessary for output is completed, the CPU 201 activates the 4-channel DMAC 204 according to an instruction from the CPU 201, and transfers the stored compressed data for four colors from the page memory 205 to the image data output unit 260.

  The image data output unit 260 includes decoder units 261a to 261d, temporary storage buffer memories 262a to 262d, and an engine I / F unit 263.

  The decoder units 261a to 261d convert the compressed data into an output image data format suitable for the printer engine unit 280. The engine I / F unit 263 is connected to the printer engine unit 280 and outputs image data to the printer engine unit 280 as a video signal.

  In recent years, with an increase in resolution and speed of a printer engine, it is required to increase the transmission speed of the video signal.

However, since the video signal output from the engine I / F unit 263 is an analog signal output directly to the exposure unit, there is a limit to speeding up. On the other hand, recent advances in serial data transfer technology have made it possible to transfer image data at high speed using high-speed serial transfer technology (Patent Documents 1 and 2).
JP 2002-321407 A JP 2005-301673 A

  As described above, in an in-line color image forming apparatus, it is necessary to transfer data by overlapping four colors of cyan, magenta, yellow, and black.

  When four-color image data is transmitted in a time-sharing manner using one-channel serial data transfer means, the transfer of the color data may not be in time for the speed required by the printer engine.

  In such a case, problems such as failure to perform normal printing occur. It is also possible to avoid this problem by providing high-speed serial data transfer means for each color.

  However, this requires a plurality of serial data transfer means. According to this method, since a plurality of serial data transfer units are provided, the cost of the image forming apparatus is increased.

  This problem can also be avoided by providing a page memory in the printer engine and transferring data for one page to the printer engine in advance.

  However, according to this method, since it is necessary to provide an expensive page memory, the cost of the image forming apparatus is increased.

  The present invention has been made to solve the above problems. The object of the present invention is to enable efficient use of serial data transfer means, and to realize high-reliability image data transfer at low cost without providing a page memory in the multi-channel serial data transfer means and the printer engine part, which increases costs. It is to provide a mechanism to do.

  The present invention includes a first image processing unit, a second image processing unit that performs image processing for each color on the image data for each color image-processed by the first image processing unit, and for each color Transfer means for transferring the image data from the first image processing unit to the second image processing unit, and an image based on the image data for each color image-processed by the second image processing unit An image forming apparatus having an image forming unit for each color to be formed, wherein the first image processing unit transfers the image data for each color by using the transfer unit for each color in a time-sharing manner. The control means controls the priority for each color when using the transfer means based on the color order of image formation and the transferred data amount of the image data for each color. It is characterized by determining.

  In addition, the present invention provides a first image processing unit, a second image processing unit that performs image processing for each color on the image data for each color image-processed by the first image processing unit, Based on the transfer means for transferring the image data for each color from the first image processing unit to the second image processing unit, and the image data for each color subjected to image processing by the second image processing unit An image forming apparatus having an image forming unit for each color that forms an image in the image, wherein the first image processing unit uses the transfer unit for each color in a time-sharing manner to obtain the image data for each color. The second image processing unit includes a storage unit that stores the image data for each color transferred by the transfer unit, and an image forming unit that is stored in the storage unit and is still image forming. Image data for each color that has not been performed Notification means for notifying the first image processing section of the remaining amount of data indicating the data, and the control means is notified by the notification means of the priority for each color when using the transfer means. It is determined based on the remaining data amount for each color.

  According to the present invention, it is possible to use serial data transfer means efficiently, and high-reliability image data with an inexpensive configuration that does not include a page memory in a multi-channel serial data transfer means or a printer engine unit, which increases costs. You can transfer.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is a block diagram showing a configuration relating to image data transfer of an inline laser beam printer showing a first embodiment of the present invention.

  The system according to this embodiment is divided into a controller unit 1 and a printer engine unit 3, and serially transfers image data between the controller unit 1 and the printer engine unit 3 using high-speed serial data transfer means 2.

  In this embodiment, image data of four colors of cyan, yellow, magenta, and black is transferred using the serial data transfer means 2 of one channel.

  The CPU 11 controls the entire apparatus and generates image data (raster data image) that can be output to the printer engine unit 3 from print data received from the external interface 13. The ROM 12 stores processing procedures (programs) processed by the CPU 11, font data, and the like.

  An external interface (external I / F) 13 is a LAN interface such as Ethernet, and an I / O interface such as USB, IEEE1284, and IEEE1394, and receives image data from a host device (host computer).

  The image memory 14 temporarily stores image data for one page or one band generated by the CPU 11. At this time, in order to save memory capacity, the CPU 11 can compress the image data and store the compressed data.

  The image data output unit 15 transfers the image data from the image memory 14 for each color and outputs the image data to the printer engine unit 3. The printer engine unit 3 is an inline laser beam printer, and requires simultaneous transfer of image data of a plurality of colors.

  Hereinafter, the internal configuration of the image data output unit 15 will be described.

  19, 20, 21, and 22 are FIFO (First In First Out) memories for each color, and image data (raster image data) for each color stored in the image memory 14 is transferred by the DMA access control unit 18. The

  When the CPU 11 designates an area of the image memory 14 that is the transfer source and one of the FIFOs 19, 20, 21, and 22 for each color of the transfer destination by the CPU 11 and receives an activation command, the image access memory 18 The image data transfer from the designated area 14 to the designated FIFO is started.

  Further, the DMA access control unit 18 starts the transfer, and transmits to the multiplexer unit 23 that the head of the page data has been transmitted via the signal line 25.

  The multiplexer unit 23 selects the data stored in the FIFOs 19, 20, 21, and 22 and transfers the data stored in the selected FIFOs to the printer engine unit 3 using the serializer 17 and the serial data transfer unit 2. Is to do.

  The serializer 17 converts the parallel data input from the FIFO into serial data and performs high-speed serial data transfer such as 600 Mbps to 1 Gbps.

  The multiplexer unit 23 includes means for generating packet data for each color from the data stored in the FIFOs 19, 20, 21, and 22 and counting the number of packets transferred to the serializer 17.

  In this embodiment, the packet generation circuit (not shown) in the multiplexer unit 23 divides the image data from the FIFOs 19, 20, 21, and 22 every 1024 bytes, and the 8B10B encoding circuit (not shown) Bit data is converted to 10-bit data. The data divided into 1024 bytes and converted into 10 bits is used as a payload, and the packet data is obtained by using the bits in the 10-bit data that are not assigned to the 8-bit data by the 8B10B conversion circuit as the header. Generate.

  As header types, one type is used for training for establishing a communication path, four types are used for data transfer of C, M, Y, K, and each color is used. There are a total of 9 types.

  When the data is packetized, the multiplexer unit 23 selects one of four types of data transfer headers as a header according to the FIFOs 19, 20, 21, and 22 that receive the data. That is, if the data is from the FIFO 19, the data transfer header 1, the data from the FIFO 20 is the data transfer header 2, the data from the FIFO 21 is the data transfer header 3, and the data from the FIFO 22 is the data transfer Header 4 is selected. That is, the multiplexer unit 23 allocates a packet header for each color.

  For the first payload after recognizing the head of the page data via the signal line 25, the multiplexer unit 23 sets the header for the head of the page data according to the FIFOs 19, 20, 21, and 22 that receive the data. select. That is, the multiplexer unit 23 allocates a packet header so that the head of the page can be identified.

  The multiplexer unit 23 arbitrates transfer of image data from the FIFOs 19, 20, 21, and 22 based on the number of transferred packets.

  Next, the configuration of the printer engine unit 3 will be described.

  In the printer engine unit 3, the deserializer 31 converts the serial data transferred by the serial data transfer means 2 into parallel data.

  The demultiplexer unit 32 recognizes the type of image data of the packet data based on the packet header of the packet data converted into parallel data by the deserializer 31. Further, the demultiplexer unit 32 converts the payload data of the parallel data into 8-bit data by a 10B8B encoding circuit (not shown), and converts the converted parallel image data into the FIFOs 33, 34, 35, and 36 of the color. Sort and transfer.

  Each color FIFO 33, 34, 35, 36 stores image data and transfers the data to the image processing units 37, 38, 39, 40.

  The image processing units 37, 38, 39, and 40 for each color perform image processing such as γ correction and halftone processing on the data transferred from the FIFO. The image processing units 37, 38, 39, and 40 include a lookup table, and can perform appropriate image processing according to the print image by changing the γ table and the halftone table. The image processing units 37, 38, 39, and 40 can perform image processing according to the characteristics of the printer engine unit 3 by changing the lookup table based on feedback from various sensors of the engine (not shown). it can.

  The video signal conversion units 41, 42, 43, and 44 convert the image data (raster image data) transferred from the image processing units 37, 38, 39, and 40 into video signals (video data) that control the lighting of the laser. Then, the lasers of the scanner units 45, 46, 47, and 48 are controlled. The video signal converters 41, 42, 43, and 44 control the exposure timing based on the horizontal synchronization signals from the scanner units 45, 46, 47, and 48.

  The scanner units 45, 46, 47, and 48 control the lighting of the laser according to the video signal, expose a photosensitive drum (not shown), and output a horizontal synchronization signal to the video signal conversion units 41, 42, 43, and 44. . The scanner unit 45 is a first color image forming unit, the scanner unit 46 is a second color image forming unit, the scanner unit 47 is a third color image forming unit, and the scanner unit 48 is a fourth color image forming unit. Yes, images are formed in the order of the first color, the second color, the third color, and the fourth color.

  In the above configuration, the CPU 11 receives data sent from the host computer via the external interface 13, generates image data in a format that can be output to the printer engine unit 3, and stores the image data in the image memory 14.

  When a predetermined amount (page or band of a predetermined size) of image data is generated, the CPU 11 notifies the printer engine unit 3 of an instruction to start printing via an engine interface circuit (not shown).

  Upon receiving this print start instruction, the printer engine unit 3 starts a printing operation and outputs a vertical synchronization signal indicating the transfer timing of the image data. An engine interface circuit (not shown) notifies the CPU 11 of the data transfer timing of each color based on the vertical synchronization signal received from the printer engine unit 3.

  As a result, the CPU 11 activates a DMA controller (not shown) in the DMA access control unit 18 for the color to be transferred to the printer engine unit 3 to transfer image data.

  The image data transferred and stored in the FIFOs 19, 20, 21, and 22 by the DMA controller is controlled by the multiplexer unit 23 and transferred to the printer engine unit 3.

  At that time, the multiplexer unit 23 forms a packet for each FIFO and transfers the data of the FIFOs 19, 20, 21, and 22 to the serializer 17.

  Hereinafter, with reference to FIG. 2, the operation of the multiplexer unit 23 in the first embodiment of the present invention (setting the priority order of FIFO data transfer for each color) will be described.

  FIG. 2 is a flowchart for explaining the operation of the multiplexer unit 23 in the first embodiment of the present invention.

  In FIG. 2, n1 denotes the second station (scanner unit 46 as the second image forming unit) from the exposure start time (image formation start) of the first station (scanner unit 45 as the first image forming unit). ) Is the number of image data of the first station necessary (to be transferred) for the exposure to the exposure start time.

  n2 is the number of image data of the second station necessary for exposing the time from the exposure start time of the second station to the exposure start time of the third station (the scanner unit 47 as the third image forming means). It is.

  n3 is the number of image data of the third station necessary for exposing the time from the exposure start time of the third station to the exposure start time of the fourth station (the scanner unit 48 as the fourth image forming means). It is.

  M1 is the number of data satisfying 0 <m1 ≦ n1. For example, m1 = n1 / 2 is preferable. m2 is the number of data satisfying 0 <m2 ≦ n2. For example, m2 = n2 / 3 may be set. m3 is the number of data satisfying 0 <m3 ≦ n3. For example, m3 = n3 / 4 may be set. Needless to say, m1 to m3 are not limited to this, and are changed according to the configuration of the serial data transfer unit 2, the printer engine unit 3, and the like.

  First, the multiplexer unit 23 checks whether or not there is a transfer request for the FIFOs 19, 20, 21, and 22 (S1). If it is determined that there is no transfer request, the multiplexer unit 23 waits until there is a transfer request.

  On the other hand, if it is determined in S1 that there is a transfer request, the multiplexer unit 23 checks whether or not there are a plurality of FIFOs having a data transfer request (S2).

  If it is determined in S2 that there is one FIFO requesting data transfer, the multiplexer unit 23 transfers the FIFO data of the station requesting the data transfer (S3). Then, the process returns to S1 and waits for the next data transfer request.

  On the other hand, if it is determined in S2 that there are a plurality of FIFOs requesting data transfer, the multiplexer unit 23 refers to the number of data transferred to each station.

  First, the multiplexer unit 23 confirms the number of transmitted packets to the first station (S4). That is, it is confirmed whether the condition “the number of packets transmitted to the first station (ch1) is m1 or less” is satisfied.

  If it is determined that the condition of S4 is satisfied (Y in S4), the multiplexer unit 23 gives priority to the transfer request from the FIFO 19 of the first station and transfers the data of the FIFO 19 of the first station (S5). ). In this case, the multiplexer unit 23 performs transfer control so that priority is given to the transfer of the color image data corresponding to the FIFO 19 until the transferred data amount of the color image data corresponding to the FIFO 19 exceeds m1.

  On the other hand, if it is determined that the condition of S4 is not satisfied (N in S4), the multiplexer unit 23 confirms the number of transferred packets to the first station and the second station (S6). That is, it is confirmed whether the condition “the number of packets transmitted to the first station (ch1) is n1 + m2 or less” and “the number of packets transmitted to the second station (ch2) is m2 or less” is satisfied.

  If it is determined that the condition of S6 is satisfied (Y in S6), the multiplexer unit 23 transfers the data of the FIFOs 19 and 20 of the first and second stations in round robin (S7). In this case, priority is given to the transfer of the first and second color image data until the transferred data amount of the first color image data exceeds m1 and the transferred data amount of the second color image data exceeds m2. The image data is transferred using the serial data transfer means 2 in a time division manner for the first and second colors.

  On the other hand, when determining that the condition of S6 is not satisfied (N in S6), the multiplexer unit 23 checks the number of transferred packets of the first, second, and third stations (S8). That is, “the number of transmitted packets to the first station (ch1) is n1 + n2 + m3 or less” and “the number of transmitted packets to the second station (ch2) is n2 + m3 or less” and “the number of transmitted packets to the third station (ch3) ) Satisfies the condition of “m3 or less”.

  If it is determined that the condition of S8 is satisfied (Y in S8), the multiplexer unit 23 transfers the data of the FIFOs 19, 20, and 21 of the first, second, and third stations in round robin (S9). ). In this case, the transferred data amount of the first color image data exceeds n1 + n2 + m3, the transferred data amount of the second color image data exceeds n2 + m3, and the transferred data amount of the third color image data exceeds m3. Until then, the image data transfer of the first to third colors is given priority, and the image data is transferred for the first to third colors using the serial data transfer means 2 in time division.

  On the other hand, if it is determined that the condition of S8 is not satisfied (N in S8), the multiplexer unit 23 causes the FIFOs 19, 20, 21, and 22 of all the stations (first, second, third, and fourth stations). Are transferred in round robin (S10). In this case, the serial data transfer means 2 is used for time division in all colors to transfer image data for all colors.

  When the processes of S3, S5, S7, S9, and S10 are completed, the process returns to S1 and waits for the next data transfer request.

  As described above, the multiplexer unit 23 uses the serial data transfer unit 2 in a time-sharing manner for each color, and converts the image data for each color from the first image processing unit (controller unit 1) to the second image processing unit (printer). It is transferred to the engine unit 3 including 31-44 and the like. At this time, the multiplexer unit 23 controls to determine the priority for each color when using the serial data transfer unit 2 based on the color order of image formation and the transferred data amount of image data for each color. .

  Therefore, according to the first embodiment, when transferring image data of each color, it is possible to change the priority of image data transfer of the corresponding FIFO according to the number of data transferred by serial data transfer.

  As a result, the serial data transfer means 2 can be used in the order of data required by the printer engine unit 3, and data can be transferred efficiently.

  Therefore, by using the single-channel serial data transfer means 2, a highly reliable image data transfer can be made inexpensively without providing a page memory in the multiple-channel serial data transfer means or the printer engine unit 3 that would increase the cost. Can be realized.

  In this embodiment, the serial data transfer rate is set to 600 Mbps to 1 Gbps, but is not limited to these transfer rates.

  In addition, since the printer engine unit 3 includes a FIFO, it is possible to start the transfer of image data at the same time that the controller unit 1 issues a print start instruction without waiting for the vertical synchronization signal of the engine.

  In the above description, the number of data is counted and used for setting priority. However, when serially transferring data in units of packets, the number of packets may be counted and used for setting priority. In the case of this configuration, the same control can be performed with the same control method.

[Second Embodiment]
FIG. 3 is a block diagram showing a configuration relating to image data transfer of the inline laser beam printer showing the second embodiment of the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals, and the description of the portions described in FIG. 1 is omitted.

  In FIG. 3, the FIFOs 33, 34, 35, and 36 of the printer engine unit 3 output the remaining data (FIG. 4) to the demultiplexer unit 32.

  The demultiplexer unit 32 transfers the remaining data amount of each FIFO to the serializer 49 in a round robin manner. The serializer 49 transfers the remaining data amount of each FIFO to the deserializer 24 of the controller unit 1 through the serial data transfer means 50. That is, the printer engine unit 3 according to the present embodiment is configured to notify the controller unit 1 of the remaining amount of data indicating the amount of image data for each color that has been accumulated in the FIFOs 33, 34, 35, and 36 and has not yet been formed. Have.

  Based on the information from the deserializer 24, the multiplexer unit 23 can sequentially know the remaining amount of data in the FIFOs 33, 34, 35, and 36 of the printer engine unit 3. Then, the multiplexer unit 23 of the present embodiment determines and controls the priority for each color when using the serial data transfer unit 2 based on the notified data remaining amount for each color (details will be described later). As shown in FIG.

  FIG. 4 is a diagram showing an example of setting the priority level of the multiplexer unit 23 for the remaining amount of data stored in the FIFOs 33, 34, 35, and 36 of the printer engine unit 3 shown in FIG.

  For example, when the amount of data stored in the FIFO of the kth (k is 1 to 4) color is less than the threshold 1 (1/4), the multiplexer unit 23 sets the priority level of the kth color to “level 0”. Set.

  When the remaining data amount is equal to or greater than the threshold value 1 (1/4) and less than the threshold value 2 (1/2), the multiplexer unit 23 sets the priority level of the kth color to “level 1”.

  If the remaining data amount is equal to or greater than the threshold value 2 (1/2), the multiplexer unit 23 sets the priority level of the kth color to “level 2”.

  Note that the above-described threshold can be freely set according to data transfer capability or the like.

  Here, the priority levels are level 0> level 1> level 2 and level 0 has the highest priority.

  Hereinafter, with reference to FIG. 5, the operation of the multiplexer unit 23 in the second embodiment of the present invention (setting the priority of FIFO data transfer for each color) will be described.

  FIG. 5 is a flowchart for explaining the operation of the multiplexer unit 23 in the second embodiment of the present invention.

  First, the multiplexer unit 23 checks whether or not there is a transfer request for the FIFOs 19, 20, 21, and 22 (S81). If it is determined that there is no transfer request, the multiplexer unit 23 waits until there is a transfer request.

  On the other hand, if it is determined in S81 that there is a transfer request, the multiplexer unit 23 checks whether there are a plurality of FIFOs with data transfer requests (S82).

  If it is determined in S82 that there is one FIFO requesting data transfer, the multiplexer unit 23 permits the FIFO requesting data transfer to access the serializer 17 (S83). ), The process proceeds to S88.

  On the other hand, if it is determined in S82 that there are a plurality of FIFOs requesting data transfer, the multiplexer unit 23 proceeds to S84.

  In S84, the multiplexer unit 23 checks whether there are a plurality of data transfer requests having the highest priority level among the priority levels of the color FIFOs 33, 34, 35, and 36 of the printer engine unit 3 (S84).

  If it is determined in S84 that there is one data request with the highest priority level, the multiplexer unit 23 permits the data transfer request for the FIFO with the highest priority level color (S85), and S88. Proceed with the process.

  When there are a plurality of data transfer requests at the highest priority level, the right to use the serializer is evenly given by a round robin method or the like.

  For example, a counter (wait counter) that counts the number of waiting times is prepared for each FIFO, and the wait counter is incremented when data transfer is not permitted even though it is the highest priority level. Then, when there are a plurality of data transfer requests at the highest priority level, the multiplexer unit 23 allows the FIFO having a large weight counter value to transfer data to the serializer.

  That is, if it is determined in S84 that there are a plurality of data requests with the highest priority level, the multiplexer unit 23 permits data transfer to the FIFO with a large number of waiting times (S86). In S87, the multiplexer unit 23 resets the FIFO wait counter that is permitted to transfer data, increments the FIFO wait counter that is not permitted to transfer data, and advances the process to S88.

  In S <b> 88, the multiplexer unit 23 transfers the transfer-permitted FIFO image data to the printer engine unit 3 via the serializer 17. Then, the process returns to S81 to wait for the next data transfer request.

  As described above, according to the second embodiment, when transferring image data of each color, priority is given to data transfer of the FIFOs 19 to 22 of the corresponding controller unit according to the remaining amount of data accumulated in the FIFOs 33 to 36 of the printer engine unit 3. It becomes possible to change the level dynamically.

  As a result, the priority level of data transfer can be set high for a specific color with a small remaining amount of data stored in the FIFO, and data transfer can be performed preferentially, and the serial data transfer means 2 can be used efficiently. Will be able to.

  Therefore, by using the single-channel serial data transfer means 2, a highly reliable image data transfer can be made inexpensively without providing a page memory in the multiple-channel serial data transfer means or the printer engine unit 3 that would increase the cost. Can be realized.

  It should be noted that the configuration and contents of the various data described above are not limited to this, and it goes without saying that the various data and configurations are configured according to the application and purpose.

  As described above, in the CMYK multi-value data transfer between the controller unit 1 and the printer engine unit 3, the multiplexer unit 23 packetizes data to be transferred by high-speed serial communication, and allocates a packet head for each color (CMYK). By shaking, each color is transferred in time division in one lane. In addition, a page break is detected in conjunction with the memory transfer by the DMAC, and the packet head is changed so that the head of the page is known. With such a configuration, high-speed serial data transfer means 2 can be used to realize highly reliable image data transfer at low cost.

  Although one embodiment has been described above, the present invention can take an embodiment as a system, apparatus, method, program, storage medium, or the like. Specifically, the present invention may be applied to a system composed of a plurality of devices, or may be applied to an apparatus composed of a single device.

  The operation of the multiplexer unit 23 shown in the flowcharts of FIGS. 2 and 5 may be realized by hardware or may be realized by software.

  2 and 5 are realized by software, the operation is realized by the controller in the multiplexer unit 23 reading and executing the program recorded in the memory in the multiplexer unit 23. Is done. In this case, the program code itself read from the memory realizes the novel function of the present invention, and the recording medium on which the program code is recorded constitutes the present invention.

  Therefore, as long as it has the function of a program, the form of the program is not limited, such as an object code, a program executed by an interpreter, and script data supplied to the OS. As a program supply method, the program itself according to the present invention can be downloaded from a server to the memory via the Internet. It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage.

  Further, the present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. It goes without saying that the present invention can also be applied to a case where the present invention is achieved by supplying a program to a system or apparatus. In this case, by reading a storage medium storing a program represented by software for achieving the present invention into the system or apparatus, the system or apparatus can enjoy the effects of the present invention.

  The present invention is not limited to the above embodiment, and various modifications (including organic combinations of the embodiments) are possible based on the spirit of the present invention, and these are excluded from the scope of the present invention. is not.

  Although various examples and embodiments of the present invention have been shown and described, those skilled in the art will not limit the spirit and scope of the present invention to the specific description in the present specification.

  In addition, all the structures which combined each embodiment mentioned above and its modification are also included in this invention.

1 is a block diagram illustrating a configuration related to image data transfer of an inline laser beam printer illustrating a first embodiment of the present invention. FIG. It is a flowchart for demonstrating operation | movement of the multiplexer part 23 in 1st Embodiment of this invention. It is a block diagram which shows the structure in connection with the image data transfer of the in-line laser beam printer which shows 2nd Embodiment of this invention. FIG. 4 is a diagram illustrating an example of setting a priority level of a multiplexer unit 23 with respect to the remaining amount of data stored in FIFOs 33, 34, 35, and 36 of the printer engine unit 3 illustrated in FIG. It is a flowchart for demonstrating operation | movement of the multiplexer part 23 in 2nd Embodiment of this invention. FIG. 3 is a diagram illustrating a configuration of a general printer. 6 is a timing chart showing inline print data output timing. It is a block diagram which shows the controller structure of a general inline system printer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Controller part 2 Serial data transfer means 3 Printer engine part 11 CPU
12 ROM
13 External interface (external I / F)
DESCRIPTION OF SYMBOLS 14 Image memory 16 System bus 17 Serializer 18 DMA access control part 19-22 FIFO memory 23 Multiplexer part 31 Deserializer 32 Demultiplexer part 33, 34, 35, 36 FIFO memory 37, 38, 39, 40 Image processing part 41, 42, 43, 44 Video signal conversion 45, 46, 47, 48 Scanner section

Claims (11)

A first image processing unit, a second image processing unit that performs image processing for each color on the image data for each color image-processed by the first image processing unit, and the image data for each color. Transfer means for transferring from the first image processing unit to the second image processing unit, and the color for forming an image based on the image data for each color image-processed by the second image processing unit An image forming apparatus having each image forming means,
The first image processing unit includes a control unit that controls to transfer the image data for each color by using the transfer unit for each color in a time-sharing manner,
The control means determines the priority for each color when using the transfer means based on the color order of image formation and the transferred data amount of image data for each color. apparatus. The image forming means for each color includes a first color image forming means for forming an image in the order of the first color, the second color, the third color, and the fourth color, a second color image forming means, and a third color. Image forming means, a fourth color image forming means,
The control means includes
Until the transferred data amount of the first color image data exceeds a first threshold value, control is performed so as to give priority to the transfer of the first color image data,
Further, the first and the first data are transferred until the transferred data amount of the first color image data exceeds the first threshold value and the transferred data amount of the second color image data exceeds the second threshold value. Control to give priority to the transfer of two-color image data,
Further, the first data until the transferred data amount of the second color image data exceeds the second threshold value and the transferred data amount of the third color image data exceeds the third threshold value. The image forming apparatus according to claim 1, wherein control is performed so that transfer of image data of three colors is prioritized. The first threshold value is to be transferred in the time from the start of image formation by the first color image forming unit to the start of image formation by the second color image forming unit. The value does not exceed the amount of image data,
The second threshold value is the second color value to be transferred during the time from the start of image formation by the second color image forming unit to the start of image formation by the third color image forming unit. The value does not exceed the amount of image data,
The third threshold value is the third color value to be transferred during the time from the start of image formation by the third color image forming unit to the start of image formation by the fourth color image forming unit. The image forming apparatus according to claim 2, wherein the value is a value that does not exceed a data amount of the image data. A first image processing unit, a second image processing unit that performs image processing for each color on the image data for each color image-processed by the first image processing unit, and the image data for each color. Transfer means for transferring from the first image processing unit to the second image processing unit, and the color for forming an image based on the image data for each color image-processed by the second image processing unit An image forming apparatus having each image forming means,
The first image processing unit includes a control unit that controls to transfer the image data for each color by using the transfer unit for each color in a time-sharing manner,
The second image processing unit
Storage means for storing image data for each color transferred by the transfer means;
Notification means for notifying the first image processing section of the remaining amount of data indicating the data amount of the image data for each color that has been accumulated in the storage means and has not yet undergone image formation;
The image forming apparatus according to claim 1, wherein the control unit determines a priority order for each color when using the transfer unit based on a remaining data amount for each color notified by the notification unit.   5. The image forming apparatus according to claim 1, wherein the transfer unit is a one-channel serial data transfer unit.   The image forming apparatus according to claim 1, wherein the control unit performs control so that the image data for each color is packetized and transferred.   The image forming apparatus according to claim 6, wherein the control unit performs control so that image data for each color is transferred in a time-division manner for each color by assigning a packet header for each color. apparatus.   The image forming apparatus according to claim 7, wherein the control unit allocates a header of the packet so that the head of the page can be identified. The first image processing unit generates raster image data based on print data received from a host computer,
The image forming apparatus according to claim 1, wherein the second image processing unit generates video data for image formation by the image forming unit from the raster image data. . A first image processing unit, a second image processing unit that performs image processing for each color on the image data for each color image-processed by the first image processing unit, and the image data for each color. Transfer means for transferring from the first image processing unit to the second image processing unit, and the color for forming an image based on the image data for each color image-processed by the second image processing unit An image data transfer method in an image forming apparatus having each image forming means,
A transfer control step in the first image processing unit for controlling to transfer the image data for each color by using the transfer means in time division for each color;
The transfer control step determines an order of priority for each color when using the transfer unit based on a color order of image formation and a transferred data amount of image data for each color. Data transfer method. A first image processing unit, a second image processing unit that performs image processing for each color on the image data for each color image-processed by the first image processing unit, and the image data for each color. Transfer means for transferring from the first image processing unit to the second image processing unit, and the color for forming an image based on the image data for each color image-processed by the second image processing unit An image data transfer method in an image forming apparatus having each image forming means,
A transfer control step in the first image processing unit for controlling to transfer the image data for each color using the transfer means in a time-sharing manner for each color;
An accumulation step in the second image processing unit for accumulating the image data for each color transferred by the transfer unit in a storage unit of the second image processing unit;
Notification in the second image processing unit that notifies the first image processing unit of the remaining amount of data indicating the data amount of the image data for each color that has been stored in the storage means in the storage step and has not yet been imaged. And having steps
The transfer control step determines the priority for each color when using the transfer means based on the remaining data amount for each color notified by the notification step. .

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