JP2008302583A - Printing controlling circuit and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing controlling circuit enabling an efficient printing controlling by writing information related to setting of printing of the next page on a register during printing for the present page when a plurality of pages are continuously printed. <P>SOLUTION: The printing controlling circuit is composed of a PCU 41 for performing the setting of the printing for an image forming apparatus, an engine controlling ASIC 10 for controlling a printing engine for the image forming apparatus according to the setting of the printing from the PCU 41, and a function expanding ASIC 20 provided between the engine controlling ASIC 10 and the PCU 41 and for expanding the function of the engine controlling ASIC 10. The function expanding ASIC 20 is equipped with a COMFIFO 32 for storing the information related to the setting of the printing of the next page during printing for an arbitrary page of the image data, and according to the controlling from the PCU 41, the setting of the printing stored in the COMFIFO 32 is stored in the register 12 on the engine side and in the register 27 on the function expanding side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a print control circuit and an image forming apparatus, and more particularly to a print control circuit that controls a printing process in continuous printing of a plurality of pages and an image forming apparatus including the circuit.

  In recent years, market prices of image forming apparatuses such as MFPs (digital multifunction peripherals) have been decreasing, and further cost reduction has been demanded. Therefore, an ASIC (Application Specific Integrated Circuit) is being developed in which all functions related to print control of the image forming apparatus are incorporated into one chip without using a general-purpose CPU, ROM, RAM, or the like. By using the ASIC, it is possible to reduce the size, reduce power consumption, and reduce costs.

  FIG. 8 is a block diagram illustrating a configuration example of a print control circuit included in a conventional image forming apparatus. In FIG. 8, 100 is an engine control ASIC, 200 is a function expansion ASIC, 401 is a PCU (Process Control Unit), and 402 is an image. A process ASIC 403 indicates a print engine. This image forming apparatus exemplifies a so-called high-end model having multiple functions, and includes a function expansion ASIC 200 in addition to the engine control ASIC 100. The engine control ASIC 100 has a minimum circuit configuration necessary to satisfy the specifications of a low-priced model shown in FIG. On the other hand, the function expansion ASIC 200 is mounted in order to expand the function of the engine control ASIC 100 and satisfy the specifications of the high-end model. As this extended function, there are, for example, high resolution, multiple beams, and the addition of a print pattern associated therewith.

  A PCU 401 is a process control unit and is a CPU for controlling mechanisms such as motors and sensors provided in the image forming apparatus. The image processing ASIC 402 receives image data read by the CCD, performs image processing, and outputs the image data subjected to the image processing to the print engine 403 via the function expansion ASIC 200 and the engine control ASIC 100. The print engine 403 includes a laser scanning unit (LSU) that controls a laser and performs a printing process.

  The engine control ASIC 100 generates a PCUIF 101 for performing various print settings (print area setting, print start setting, etc.) from the PCU 401, a register 102 for storing various print settings from the PCU 401, a print check pattern, and the like. The pattern generation circuit 103, an input IF 104 that receives print data from the image processing ASIC 402, a RAM 105 that temporarily stores the print data, and an output IF 106 that transmits the print data to the print engine 403 are provided.

  The function expansion ASIC 200 includes a PCUIF input unit 201 serving as an input interface from the PCU 401, selectors 202 to 204 for switching input / output, a PCUIF output unit 205 serving as an output interface to the PCUIF 101 included in the engine control ASIC 100, and a PCU 401 A PCUIF 206 for performing various print settings, a register 207 for storing various print settings from the PCU 401, a pattern generation circuit 208 for generating a print check pattern and the like, and an input IF 209 for receiving print data from the image processing ASIC 402 A RAM 210 that temporarily stores print data, and an output IF 211 that transmits the print data to the print engine 403.

  FIG. 9 is a block diagram illustrating another configuration example of the print control circuit included in the conventional image forming apparatus. The image forming apparatus of this example is a so-called low-priced model having a smaller function than that of the image forming apparatus of FIG. 8, and does not have a function expansion ASIC, and is configured only by an engine control ASIC. As described above, the engine control ASIC has a minimum circuit configuration necessary to satisfy the specifications of a low-priced model.

  In the image forming apparatus shown in FIGS. 8 and 9, when the page information related to the print setting is transmitted from the PCU to the engine control ASIC, since it is performed between the print pages, if the transmission of the page information is delayed between the pages, Printing could be delayed, hindering high-speed printing. In addition, since serial communication such as UART (Universal Asynchronous Receiver Transmitter) is used to prevent the influence of noise between the units, the communication speed is lowered and high-speed printing is affected. This will be described based on the timing chart of FIG.

  FIG. 10 is a timing chart for explaining print control processing by a conventional image forming apparatus. In the figure, T1 is a register setting time before starting printing, T2 is a printing time for page 1, T3 is a time between pages 1 and 2, T4 is a printing time for page 2, and T5 is a register setting changed between papers. Indicates the time to do. Here, a process for continuously printing a print job of a plurality of pages in A4 size will be described.

  In a conventional image forming apparatus, if a case occurs in which the print area setting of the next page is changed during continuous printing of a plurality of pages, it is necessary to rewrite the register settings within the paper interval time T3. Note that the case where the print area setting is changed may be, for example, when the paper size of the next page is different or when the center position is adjusted. In this case, the higher the model, the shorter the paper interval time T3, and the shorter the time T5 during which the register settings such as the print area can be rewritten without interrupting continuous printing.

  The PCU also controls many other motors / sensors at the same time between sheets during continuous printing, and it is not desirable to prioritize the register setting of the engine control ASIC. Further, it is not easy for the PCU to guarantee that the change of the register setting of the engine control ASIC is finished within the paper interval time. If the register setting is delayed, the trigger for starting printing is delayed. As a result, the paper interval time T3 is extended, which also affects the number of printable sheets per unit time.

  When the register is configured to include only one job in this way, it is necessary to finish the register setting (printing area setting, etc.) for page 2 before the start of the printing time T4, and it is rewritten at the printing time T2. Since the print area of page 1 is changed, it must be completed within the paper interval time T3.

  On the other hand, if the ASIC has registers for storing print area settings for a plurality of jobs (here, both pages 1 and 2), the print area setting for page 1 is performed at the register setting time T1, and the page No. 2 printing area setting (corresponding to the register setting time T5) may be performed between the printing time T2 and the inter-paper time T3). Since the printing time T2 >> the register setting time T5, the burden on the PCU is reduced. The

  However, in the case of a low-priced ASIC, in order to minimize the circuit scale, it is not practical to use a register having a double buffer configuration and to have more than 2 × jobs, resulting in an increase in the number of gates, resulting in a cost increase.

Furthermore, the communication between the PCU and the engine control ASIC may be serial communication for the following reasons, which increases the register setting time T5 for setting the printing area and affects high-speed printing. Become.
(1) In the case of a low-priced ASIC, it is better to reduce the number of terminals as much as possible in order to reduce costs, and serial communication is desirable (number of terminals: serial <parallel).
(2) Due to the property of controlling the laser, the ASIC and the PCU may be placed on different boards in the vicinity of the laser unit, which increases the communication distance, but serial communication is anti-noise and parallel. It is advantageous compared to communication. Furthermore, by using serial communication, the number of wires of the connection harness can be reduced.
Note that when the communication distance is long, the serial communication transfer rate cannot be increased beyond a certain level, so the communication rate is further reduced and the register setting time T5 is increased.

Here, with respect to the prior art that enables register setting during printing, Japanese Patent Application Laid-Open No. 2004-228561 discloses that when print data includes blank data, the setting value set in the register during transmission of blank data is a bus. It is described above that the register can be set even during printing.
JP 2003-320716 A

  According to the technique described in Patent Document 1, even during printing, by outputting a value to be written to a register to a commonly used bus, bus sharing and early writing to the register can be performed. Although it is possible, the timing at which data can be written to the register during printing is only the timing when the print data is blank, and writing to the register is not possible when there is no blank in the print data. Therefore, in the conventional techniques including Patent Document 1, it is difficult to perform printing by operating the image forming apparatus at high speed due to register setting restrictions.

  The present invention has been made in view of the above circumstances, and in the case of continuous printing of a plurality of pages, information related to print settings for the next page is written into a register during the printing of the current page. An object of the present invention is to provide a print control circuit capable of print control and an image forming apparatus including the circuit.

  In order to solve the above problems, a first technical means of the present invention is a print control circuit of an image forming apparatus capable of continuously printing image data of two pages or more, and performs print settings of the image forming apparatus. And a second control unit that controls the print engine of the image forming apparatus in accordance with print settings from the first control unit, and the second control unit includes an arbitrary page of image data. Is provided with storage means for storing information relating to print settings for the next page during printing.

  According to a second technical means, in the first technical means, the second control unit is provided between an engine control unit that controls a print engine of the image forming apparatus, and the engine control unit and the first control unit. And a function expansion unit for expanding the function of the engine control unit, and the function expansion unit is provided with a storage means.

  According to a third technical means, in the second technical means, the engine control unit and the function expansion unit include a register for storing print settings from the first control unit, and the function expansion unit includes the first control unit. The print settings stored in the storage means are stored in a register of the engine control unit and a register of the function expansion unit in accordance with control from the unit.

  According to a fourth technical means, in the third technical means, the function expansion unit transmits the print setting stored in the storage means to the engine control unit by a control command from the first control unit. Is.

  According to a fifth technical means, in the third technical means, the function expansion unit stores the print setting stored in the storage unit in the register of the function expansion unit and then stores the print setting in the register of the engine control unit. It is characterized by.

  According to a sixth technical means, in the third technical means, the function expansion unit stores the print settings stored in the storage unit simultaneously in a register of the function expansion unit and a register of the engine control unit. It is.

  A seventh technical means is an image forming apparatus including the print control circuit according to any one of the first to sixth technical means.

According to the present invention, during continuous printing of a plurality of pages, efficient printing control can be performed by writing information relating to the print setting of the next page to the register during printing of the current page.
More specifically, it is a case where the PCU and the engine control ASIC are connected by serial communication and the communication speed is low by writing information relating to the print setting of the next page to the engine control ASIC register during printing of the current page. However, it does not affect the printing speed.

  Further, the engine control ASIC does not need to write the information related to the print setting for the next page received from the PCU into the register within the inter-page time between pages, and simply reads the register information stored in advance during the printing of the previous page. Since the information related to the print setting for the next page can be acquired, even a high-speed machine with a short paper interval time can perform register settings without being restricted by the paper interval time.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a print control circuit and an image forming apparatus including the print control circuit according to the invention will be described with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing a configuration example of a print control circuit included in an image forming apparatus according to the present invention. In FIG. 1, 10 is an engine control ASIC, 20 is a function expansion ASIC, 41 is a PCU, 42 is an image processing ASIC, Reference numeral 43 denotes a print engine. The basic circuit configuration is the same as the configuration shown in FIG. 8 described above, except that the function expansion ASIC 20 includes a COM FIFO (command FIFO) 32 which is a main feature of the present invention.

  That is, the image forming apparatus according to the present invention is an example of a so-called high-end model having multiple functions, and includes a function expansion ASIC 20 in addition to the engine control ASIC 10. The engine control ASIC 10 has a minimum circuit configuration necessary to satisfy the specifications of a low-priced model shown in FIG. On the other hand, the function expansion ASIC 20 is mounted in order to expand the function of the engine control ASIC 10 and satisfy the specifications of the high-end model. As this extended function, there are, for example, high resolution, multiple beams, and the addition of a print pattern associated therewith.

  The PCU 41 is a process control unit and is a CPU for controlling mechanisms such as motors and sensors provided in the image forming apparatus. The image processing ASIC 42 receives image data read by a CCD or the like, performs image processing, and outputs the image data subjected to the image processing to the print engine 43 via the function expansion ASIC 20 and the engine control ASIC 10. The print engine 43 includes an LSU that controls a laser and performs a printing process.

  The engine control ASIC 10 generates a PCUIF 11 for performing various print settings (print area setting, print start setting, etc.) from the PCU 41, a register 12 for storing various print settings from the PCU 41, a pattern for print check, and the like. The pattern generation circuit 13 includes an input IF 14 that receives print data from the image processing ASIC 42, a RAM 15 that temporarily stores the print data, and an output IF 16 that transmits the print data to the print engine 403.

  The function expansion ASIC 20 includes a PCUIF input unit 21 serving as an input interface from the PCU 41, selectors 22 to 24 for switching input / output, a PCUIF output unit 25 serving as an output interface to the PCUIF 11 included in the engine control ASIC 10, and the PCU 41 A PCUIF 26 for performing various print settings, a register 27 for storing various print settings from the PCU 41, a pattern generation circuit 28 for generating a print check pattern and the like, and an input IF 29 for receiving print data from the image processing ASIC 42 A RAM 30 for temporarily storing print data; an output IF 31 for transmitting the print data to the print engine 43; and a COM FIFO 32, which is a main feature of the present invention.

  FIG. 2 is a block diagram illustrating another configuration example of the print control circuit included in the image forming apparatus according to the present invention. The basic circuit configuration is the same as that shown in FIG. 9 described above, except that the engine control ASIC 10 includes a COMFIFO 17, which is a main feature of the present invention. The image forming apparatus according to the present embodiment is a so-called low-priced model having a smaller function than that of the image forming apparatus shown in FIG. 1, and does not have a function expansion ASIC, and is configured only by an engine control ASIC. As described above, the engine control ASIC has a minimum circuit configuration necessary to satisfy the specifications of a low-priced model.

  That is, the print control circuit shown in FIG. 2 controls the print engine 43 according to the print setting from the PCU 41 corresponding to the first control unit of the present invention for performing print settings of the image forming apparatus and the PCU 41. And an engine control ASIC 10 corresponding to a second control unit. The engine control ASIC 10 includes a COM FIFO 17 corresponding to the storage unit of the present invention for storing information related to the print setting of the next page while printing an arbitrary page of image data.

  Further, it may be configured like a print control circuit shown in FIG. That is, the print control circuit shown in FIG. 1 is provided between the engine control ASIC 10 corresponding to the engine control unit of the present invention that controls the print engine 43, and between the engine control ASIC 10 and the PCU 41, and extends the functions of the engine control ASIC 10. The function expansion ASIC 20 corresponding to the function expansion unit of the present invention may be configured, and the function expansion ASIC 20 may include a COM FIFO 32.

When configured as shown in FIG. 1, the engine control ASIC 10 and the function expansion ASIC 20 include registers (register 27 and register 12, respectively) for storing print settings from the PCU 41, and the function expansion ASIC 20 follows the control from the PCU 41. The print settings stored in the COM FIFO 32 are stored in the registers 27 and 12.
At this time, the function expansion ASIC 20 performs control so that the print setting stored in the COM FIFO 32 is transmitted to the engine control ASIC 10 with a control command from the PCU 41 as a trigger.

  The function expansion ASIC 20 may store the print settings stored in the COM FIFO 32 in the register 27 of the function expansion ASIC 20 before storing the print settings in the register 27 of the engine control ASIC 10, or register the print settings stored in the COM FIFO 32. And may be simultaneously stored in the register 12 of the engine control ASIC 10. These processes will be described based on the flow of FIGS. 6 and 7 described later.

Hereinafter, the COMFIFO 32 shown in FIG. 1 will be described as a representative example, but it is needless to say that similar effects can be obtained even with the COMFIFO 17 of FIG.
The COMFIFO 32 included in the function expansion ASIC 20 is a RAM for storing register settings for the next page (that is, information relating to print settings for the next page) during printing of the current page, and functions according to a trigger (control command) from the PCU 41. The extension ASIC 20 performs register setting for the function extension ASIC 20 itself and register setting for the engine control ASIC 10.

  With the functions as described above, the PCU 41 can perform the register setting for the next page during the current printing even during continuous printing, and does not have to complete the register setting for the next page within the paper interval. This eliminates the conventional restriction that it must not be performed, and enables efficient printing processing.

  FIG. 3 is a block diagram for explaining a configuration example around the COM FIFO included in the print control circuit of the present invention. In the figure, the COM FIFO 32 includes a FIFO 321 that is a memory that receives and accumulates control signals and data from the PCUIF 26, an engine ASICIF 322 that is an interface with the PCUIF output unit 25, and an extended ASICIF 323 that is an interface with the register 27. The FIFO 321 includes a RAM 321a, two WRCNT (write counter) 321b, and two RDCNT (read counter) 321c. Note that “WR” means a write signal, and “RD” means a read signal.

  Among various signals transmitted from the PCUIF 26 to the COMFIFO 32, “WR_DATA” indicates a data (16 bits) write signal, of which “WR_ADD” is a register address (12 bits) and “BYTE_WORDn” is a byte word (1 bit). “W_DAT_EN” indicates write data enable (1 bit), “RD_WRn” indicates read / write switching (1 bit), and “CS” indicates chip select (1 bit) indicating that the FIFO 321 has been selected.

  Of the signals transmitted from the engine ASICIF 322 to the PCUIF output unit 25, “SCI_RST” indicates serial reset, “TRNS_DAT” indicates write data, “SCI_CLK” indicates serial clock, and “COM_FIFO_EN” indicates COMFIFO enable. “LOAD_TRIG” transmitted from the register 27 to the extended ASICIF 323 indicates loading of the trigger signal.

  FIG. 4 is a diagram showing an example of an address map according to the present invention. 3 and 4, the PCUIF 26 recognizes the register setting of the next page for writing from 2000h to 3FFFh, and writes to the COMFIFO 32. For writing from 0000h to 1FFFh, it is determined that the register setting is not stored in the COM FIFO 32, and writing to the engine control ASIC 10 and the function expansion ASIC 20 is performed. In writing to the COM FIFO 32, the XXX portion of 2_XXXh corresponds to the address (12 bits) of the engine control ASIC 10, and the YYY portion of 3_YYYh corresponds to the address (12 bits) of the function expansion ASIC 20. Note that the read access is not stored in the COM FIFO 32, but the engine control ASIC 10 and the function expansion ASIC 20 are accessed.

The RAM 321a stores write data, address, and access (Byte / Word) for the next page from the PC UIF 26 to the engine control ASIC 10 and the function expansion ASIC 20.
The WRCNT 321b is a write counter, and two WRCNTs 321b are provided to count the written register settings for each of the engine control ASIC 10 and the function expansion ASIC 20. At the time of a load trigger from the register 27, the number of register accesses counted by this counter is transmitted to the engine control ASIC 10 and the function expansion ASIC 20.
The RDCNT 321c is a reading counter, and two RDCNTs 321c are provided for counting the number of commands written to the register 27 of the function expansion ASIC 20 and the number of commands transmitted to the engine control ASIC 10, respectively.

  FIG. 5 is a timing chart for explaining an example of print control processing by the image forming apparatus of the present invention. In this example, a description will be given comparing the case of the present invention using the COMFIFO 32 and the conventional case. In the figure, T1 is a register setting time before the start of printing, T2 is a printing time for page 1, T3 is a time between pages 1 and 2, T4 is a printing time for page 2, and T5 is a register setting between conventional papers. T6 indicates a time for changing the register setting between sheets of the present invention, T7 indicates a time for changing the register setting of the function expansion ASIC 20, and T8 indicates a time for changing the register setting of the engine control ASIC 10. Here, a process for continuously printing a print job of a plurality of pages in A4 size will be described.

  With respect to the register setting time T1 and the register change time T5 shown in FIG. 5, in this example, the register setting is performed in the order of the engine control ASIC 10 to the function expansion ASIC 20, but in reality, the PCU 41 is not restricted in the writing order. Therefore, it is desirable to set without distinguishing between engine / function expansion.

  In the conventional case, control is performed so that register setting is completed before printing of the next page is started, and printing of the next page is started thereafter. In this case, the print settings for page 2 (such as print area settings) cannot be made until the printing of page 1 is completed. That is, it is necessary to finish the register setting for page 2 before the start of the printing time T4, and if it is rewritten at the printing time T2, the printing area of the page 1 is changed. Had to be completed.

  On the other hand, when COMFIFO 32 is used, during the printing of page 1, the print settings for page 2 (such as print area settings) to engine control ASIC 10 and function expansion ASIC 20 are written into COMFIFO 32 of function expansion ASIC 20. Then, after the printing of page 1 is finished, the function expansion ASIC 20 independently downloads in the order of the following (1) and (2) by the trigger from the PCU 41.

(1) Write to the register 27 of the function expansion ASIC 20 from the COM FIFO 32. At this time, access from the PCU 41 to the engine control ASIC 10 and the function expansion ASIC 20 is disabled.
(2) Write to the register 12 of the engine control ASIC 10 from the COM FIFO 32. At this time, access from the PCU 41 to the function expansion ASIC 20 is permitted, and access from the PCU 41 to the engine control ASIC 10 is disabled.

  During downloading from the COM FIFO 32, access from the PCU 41 to the engine control ASIC 10 and the function expansion ASIC 20 is disabled. In order to shorten the inaccessible time as much as possible, the above (1) is executed first. This is because when the communication from the function expansion ASIC 20 to the engine control ASIC 10 is serial communication, the write time from the COM FIFO 32 to the function expansion ASIC 20 is shorter than the write time from the COM FIFO 32 to the engine control ASIC 10.

  Further, in order for the PCU 41 to recognize that the access is not possible during the download or that an error has occurred during the download, it is desirable that the access prohibition period between the PCU 41 and the function expansion ASIC 20 is as short as possible.

  Further, since the print setting of page 2 is written in COMFIFO 32 during the printing of page 1, there is no restriction on the paper interval time T 3, so serial communication is performed between PCU 41 and engine control ASIC 10. As a result, even if the register setting time is increased, the printing speed is not lowered and the printing process is not delayed.

  FIG. 6 is a flowchart for explaining an example of print control processing by the print control circuit of the present invention. In this example, the case where the register setting for page 2 is set while printing page 1 will be described with reference to FIGS. 1 and 3 based on the timing chart shown in FIG. First, the PCU 41 determines whether or not to clear each read / write counter (WRCNT 321b, RDCNT 321c) of the function expansion ASIC 20 (step S1), and when each counter is cleared (in the case of YES), the function expansion ASIC 20 In accordance with control from the PCU 41, each read / write counter is cleared (step S2).

  Further, in step S1, the PCU 41 does not clear each counter of the function expansion ASIC 20 (in the case of NO), determines the read / write access (step S3), and does not have the read / write access (in the case of NO). ), And shifts to a standby state in step S3. If there is a read / write access in step S3 (YES), the function expansion ASIC 20 determines whether the access from the PCU 41 is a write access (step S4).

  If the function expansion ASIC 20 determines in step S4 that the PCU 41 is not a write access, that is, if there is a read access (NO) (decodes the register address), the function expansion ASIC 20 / engine control ASIC 10 is accessed (step S6). On the other hand, if it is determined in step S4 that there is a write access from the PCU 41 (in the case of YES), the register address (ADD) is decoded and it is determined whether ADD is 2_XXh, 3_XXh, or ELSE (step). S5).

  In step S5, the function expansion ASIC 20 writes in the engine area of the COM FIFO 32 (step S7) when ADD is 2_XXh (in the figure, ADD: 2_XXh), and counts up the WRCNT 321b corresponding to the engine area (step S8). . On the other hand, when ADD is 3_XXh (in the figure, ADD: 3_XXh), writing to the function expansion area of COMFIFO 32 (step S9), the WRCNT 321b corresponding to the function expansion area is counted up (step S10). If the ADD is ELSE (ELSE in the figure), the process proceeds to step S6 to access the function expansion ASIC 20 and the engine control ASIC 10.

  Next, the PCU 41 determines whether or not the printing of page 1 has been completed and the paper interval time T3 until the start of printing of page 2 has been reached (step S11). If the paper interval time T3 has not been reached (NO) ) And return to step S3 to repeat the process. On the other hand, in step S11, when the paper interval time T3 is reached (YES), a download command (download COM) is transmitted to the function expansion ASIC 20 (step S12).

  Next, the function expansion ASIC 20 receives the download COM and starts downloading the print settings from the COM FIFO 32 to the register 27 and the register 12 (step S13). First, download is performed to the register 27 of the function expansion ASIC 20, the RDCNT 321c corresponding to the function expansion area is counted up (step S14), and whether or not the value of the RDCNT 321c corresponding to the function expansion area is equal to the value of the WRCNT 321b. Determination is made (step S15). Here, when both are not equal (in the case of NO), it returns to Step S14 and repeats processing, and when both are equal (in the case of YES), it shifts to Step S16.

  Next, the function expansion ASIC 20 downloads to the register 12 of the engine control ASIC 10, counts up the RDCNT 321c corresponding to the engine area (step S16), and whether the value of the RDCNT 321c corresponding to the engine area is equal to the value of the WRCNT 321b It is determined whether or not (step S17). Here, when both are not equal (in the case of NO), the process returns to step S16 and the process is repeated. When both are equal (in the case of YES), it is determined that the download is completed (step S18), and the series of processes is terminated.

  In the above process, access to the engine control ASIC 10 is prohibited until the download of the print setting from the COM FIFO 32 to each register is completed. The transfer state at this time can be confirmed by the status register / signal line monitor.

  FIG. 7 is a flowchart for explaining another example of the print control processing by the print control circuit of the present invention. The difference from FIG. 6 is that the COMFIFO 32 RAM is configured as a dual port so that a plurality of read accesses can be performed simultaneously. After the download COM in step S12, the register 12 of the engine control ASIC 10 and the register 27 of the function expansion ASIC 20 are accessed. It is a point to download at the same time. That is, the processes of steps S14 to S15 and the processes of steps S16 to S17 are executed in parallel.

  Although the embodiments of the print control circuit included in the image forming apparatus have been described so far, it is needless to say that the image forming apparatus including the print control circuit can be used. As this image forming apparatus, an MFP having a copying function, a printer function, a facsimile function, and a scanner function is assumed. By including the print control circuit of the present invention, an efficient printing process can be performed.

As described above, according to the present invention, during continuous printing of a plurality of pages, efficient printing control can be performed by writing information relating to print settings for the next page to a register during printing of the current page. Can do.
More specifically, it is a case where the PCU and the engine control ASIC are connected by serial communication and the communication speed is low by writing information relating to the print setting of the next page to the engine control ASIC register during printing of the current page. However, it does not affect the printing speed.

  Further, the engine control ASIC does not need to write the information related to the print setting for the next page received from the PCU into the register within the inter-page time between pages, and simply reads the register information stored in advance during the printing of the previous page. Since the information related to the print setting for the next page can be acquired, even a high-speed machine with a short paper interval time can perform register settings without being restricted by the paper interval time.

FIG. 3 is a block diagram illustrating a configuration example of a print control circuit included in the image forming apparatus according to the present invention. FIG. 6 is a block diagram illustrating another configuration example of a print control circuit included in the image forming apparatus according to the present invention. FIG. 3 is a block diagram for explaining a configuration example around a COM FIFO included in the print control circuit of the present invention. It is a figure which shows an example of the address map which concerns on this invention. FIG. 4 is a timing chart for explaining an example of print control processing by the image forming apparatus of the present invention. It is a flowchart for demonstrating an example of the printing control process by the printing control circuit of this invention. It is a flowchart for demonstrating the other example of the printing control process by the printing control circuit of this invention. FIG. 10 is a block diagram illustrating a configuration example of a print control circuit included in a conventional image forming apparatus. FIG. 10 is a block diagram illustrating another configuration example of a print control circuit included in a conventional image forming apparatus. FIG. 10 is a diagram illustrating a timing chart for explaining print control processing by a conventional image forming apparatus.

Explanation of symbols

10, 100 ... Engine control ASIC, 11, 26, 101, 206 ... PCUIF, 12, 27, 102, 207 ... Register, 13, 28, 103, 208 ... Pattern generation circuit, 14, 29, 104, 209 ... Input IF 15, 30, 105, 210 ... RAM, 16, 106 ... engine IF, 17, 32 ... COMFIFO, 20,200 ... function expansion ASIC, 21,201 ... PCUIF input unit, 22-24, 202-204 ... selector, 25, 205 ... PCUIF output unit, 31, 211 ... output IF, 41, 401 ... PCU, 42, 402 ... image processing ASIC, 43, 403 ... print engine, 321 ... FIFO, 321a ... RAM, 321b ... WRCNT, 321c ... RDCNT, 322, engine ASICIF, 323, extended ASICIF.

Claims (7)

A print control circuit of an image forming apparatus capable of continuously printing two or more pages of image data,
A first control unit configured to perform print settings of the image forming apparatus, and a second control unit configured to control a print engine of the image forming apparatus according to the print settings from the first control unit;
The print control circuit, wherein the second control unit includes a storage unit for storing information relating to a print setting of a next page while printing an arbitrary page of the image data. The print control circuit according to claim 1, wherein the second control unit is provided between an engine control unit that controls a print engine of the image forming apparatus, and the engine control unit and the first control unit. And a function expansion unit for expanding the function of the engine control unit,
A printing control circuit, wherein the storage unit is provided in the function expansion unit. The print control circuit according to claim 2, wherein the engine control unit and the function expansion unit include a register for storing print settings from the first control unit,
The function expansion unit stores the print settings stored in the storage unit in a register of the engine control unit and a register of the function expansion unit according to control from the first control unit. Control circuit.   4. The print control circuit according to claim 3, wherein the function expansion unit transmits the print setting stored in the storage unit to the engine control unit in response to a control command from the first control unit. Print control circuit.   4. The print control circuit according to claim 3, wherein the function expansion unit stores the print setting stored in the storage unit in the register of the engine control unit after first storing the print setting in the register of the function expansion unit. A print control circuit characterized by the above.   4. The print control circuit according to claim 3, wherein the function expansion unit simultaneously stores the print settings stored in the storage unit in a register of the function expansion unit and a register of the engine control unit. Print control circuit.   An image forming apparatus comprising the print control circuit according to claim 1.

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