JP2005319648A - Printer and data transfer method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer capable of performing proper printing even when flying start is possible and a plurality of pages are printed continuously. <P>SOLUTION: The printer for receiving image data transmitted from a host device and printing on a print medium by a print engine based on the received image data comprises a means for storing the received image data, and a means for reading the image data stored in the data storage means and transferring that data to the print engine side wherein flying start is not performed under such a state as a page to be printed prior to the objective page of flying start exists and a not yet printed print medium is not yet discharged from the printer, but performed at a predetermined timing under a state where a not yet discharged page does not exist. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printing apparatus capable of so-called flying start, and more particularly to a printing apparatus capable of performing proper printing even when a plurality of pages are continuously printed.

  In general, in a so-called page printer that executes print processing in units of pages, processing for receiving image data transmitted from a host device and storing it in a memory, and processing for reading out the stored image data and transferring it to a print engine And done. In such a page printer, since the print engine executes print processing in units of pages in a continuous operation, the data transfer cannot be stopped in the middle of the page after the data transfer to the print engine is started. Therefore, the image data to be transferred to the print engine needs to be received and stored in the memory when reading.

  By waiting for the image data for one page to be stored in the memory and then starting the transfer of the page to the print engine, the above condition is satisfied, and in the print processing in the print engine Although the situation that the data is not in time does not occur, there is a problem that the start time of the printing process in the print engine is delayed.

  Therefore, a so-called flying start has been proposed in which transfer to the print engine is started when a certain amount of image data is stored without waiting for the image data for one page to be stored. With such flying start, the start time of the printing process in the print engine can be advanced, and the throughput in the printer can be improved.

Regarding the timing of this flying start, there is a situation where data is not in time for the printing process in the print engine, that is, a printing failure (hereinafter referred to as an underrun error) due to the fact that image data to be transferred is not stored in the memory. It is better to be early in the range where it does not occur, and some proposals have been made on how to determine such timing (for example, the method described in Patent Document 1 below).
Japanese Patent No. 3316378

  However, in the conventionally proposed method as described above, the timing of flying start is determined from the data transmission speed from the host device to the printer, the processing speed of the print engine, the data size of the page to be processed, etc. The page before the target page was not considered.

  On the other hand, when printing is continuously performed for a plurality of pages, the data of the page before the page being received may still remain in the memory of the printer while the data is being received from the host device. If data reception is continued in such a case, depending on the capacity of the memory, the memory may become full before receiving all the data of the page being received, and data reception may not be continued. Normally, in such a case, data reception is temporarily interrupted, and after the printing process for the previous page is completed and the memory area in which the data for the previous page is stored is released, the data reception is resumed. To do.

  In a printer in which such a situation occurs, if the above-described conventional flying start method is used, the processing status of the previous page is not taken into consideration, and thus the above-described data reception interruption may occur after the flying start. At this time, if the data transfer processing from the memory to the print engine has not been completed for the previous page, the data transfer processing of the target page by the above flying start is in a standby state, but when the transfer processing of the previous page is completed Thus, the transfer process of the target page is started. However, at this point, the printing process for the previous page is not necessarily completed, in other words, the process for discharging the previous page is not necessarily completed. There is a case where the memory release described above is not yet executed. In this case, as described above, since the data reception for the target page is not resumed, a situation occurs in which the data reception remains interrupted even when the data transfer to the print engine is started. Since the flying start method is based on the assumption that data reception is continued at the time of starting data transfer, in such a situation, there is a high possibility that an underrun error will occur when data reception is not in time for data transfer. .

  SUMMARY OF THE INVENTION An object of the present invention is to provide a printing apparatus that can start flying and that can perform proper printing even when a plurality of pages are continuously printed.

  In order to achieve the above object, according to one aspect of the present invention, there is provided a printing apparatus that receives image data transmitted from a host apparatus, and a print engine performs printing on a print medium based on the received image data. A data storage unit for storing the received image data, and a unit for reading out the image data stored in the data storage unit and transferring the image data to the print engine side, and reception of the image data for one page is completed Before starting the flying start for starting data transfer to the print engine side for the page, the printing process is performed before the page that is the target of the flying start, and the printing after printing When there is an undelivered page in which the medium is not ejected from the printing apparatus, it is not performed. Performed at the timing, it is to have a data transfer unit. Therefore, according to the present invention, the flying start considering the previous page is performed, and it is possible to eliminate an underrun error caused by data reception being interrupted due to the capacity of the data storage means. Even in the case of continuous printing in which these pages are continuously processed, appropriate printing can be performed.

  Furthermore, in the above invention, the preferred mode is that the predetermined timing of the flying start performed by the data transfer means is a predetermined timing during reception of the image data of the page that is the target of the flying start. It has been corrected. As a result, the timing at which the flying start is performed becomes more accurate, and the effect of reducing the risk of an error can be obtained.

In order to achieve the above object, according to another aspect of the present invention, there is provided a printing apparatus that receives image data transmitted from a host apparatus, and a print engine performs printing on a print medium based on the received image data. A data storage means for storing the received image data; and a means for reading out the image data stored in the data storage means and transferring the image data to the print engine side. Regardless of whether or not there is an undischarged page in which the printing process is performed before the page and the print medium after printing has not yet been discharged from the printing apparatus, the print engine side When it is determined whether it is a timing to start data transfer, and it is determined that it is a timing to start the data transfer, and there is no undelivered page When the data transfer is started and there is the undischarged page, the data reception is continued without starting the data transfer, and when the undischarged page runs out And a data transfer means for starting the data transfer after the data reception is completed.

In order to achieve the above object, according to still another aspect of the present invention, image data transmitted from a host device is received and stored, and a print engine performs printing on a print medium based on the stored image data. In the data transfer method of the stored image data to the print engine in the printing apparatus, flying that starts data transfer to the print engine for the page before the reception of the image data for one page is completed In a state where there is an undischarged page in which the printing process is performed before the page that is the target of the flying start and the print medium after printing has not yet been discharged from the printing apparatus, Without performing this, it is performed at a predetermined timing when there is no undelivered page.

  Further, in the above invention, a preferable aspect thereof is that the predetermined timing at which the flying start is performed is a timing in which a predetermined timing is corrected during reception of the image data of the page targeted for the flying start. It is characterized by being.

In order to achieve the above object, according to still another aspect of the present invention, image data transmitted from a host device is received and stored, and a print engine performs printing on a print medium based on the stored image data. In the printing apparatus, the data transfer method of the stored image data to the print engine is a page on which the printing process is performed before the page for the page that is receiving the image data, and is still after printing A first step of determining whether it is a time to start data transfer to the print engine side regardless of whether there is an undischarged page in which the print medium is not discharged from the printing apparatus; If it is determined in the first step that it is the timing to start the data transfer, if there is no undelivered page, the print engine side When there is an undischarged page, the data reception is continued without starting the data transfer to the print engine side, and when there is no undischarged page. Alternatively, a second step of starting data transfer to the print engine side after the data reception of the page is completed.

  Further objects and features of the present invention will become apparent from the embodiments of the invention described below.

  Embodiments of the present invention will be described below with reference to the drawings. However, such an embodiment does not limit the technical scope of the present invention. In the drawings, the same or similar elements are denoted by the same reference numerals or reference symbols.

  FIG. 1 is a configuration diagram according to an embodiment of a printing apparatus to which the present invention is applied. The printer 2 shown in FIG. 1 is a printing apparatus according to the present embodiment. Even when the print data transmitted from the host computer 1 has a flying start setting, the paper discharge process for the previous page is performed. If the operation is not completed, the flying start is not performed, so that proper printing is performed without causing an underrun error even in continuous printing.

  A host computer 1 shown in FIG. 1 is a host device that makes a print request to the printer 2, and can be constituted by a general-purpose computer such as a so-called personal computer. The host computer 1 is provided with a print request source application and a printer driver that generates print data to be transmitted to the printer 2 in response to a request from the application (both not shown). In this printer driver, an image to be printed is generated as image data expressed by a color (for example, CMYK) used in the printer 2, and a header which is various control information is added to the generated image data for each page. The print data is generated. The generated print data is compressed and transmitted to the printer 2.

  The printer 2 is a page printer that receives print data transmitted from the host computer 1 and executes printing in units of pages, and includes a controller 10 and a print engine 20 as shown in FIG. The controller 10 receives the print data, performs necessary processing, and then performs a series of processing to be passed to the print engine 20 as an I / F 11, a DMA controller 12 (data transfer means), a data decompression circuit 13, a video. A controller 14 is provided. These processing circuits can be configured by a dedicated hardware logic circuit such as an ASIC, for example.

  The controller 10 also includes a CPU 15 (data transfer means) that controls various processes performed in the printer 2, a DRAM 16 (data storage means) mainly used as a reception buffer memory, and a ROM 17 (data transfer means) that stores programs and the like. As shown in FIG. 1, they are connected to each other so as to be able to exchange data.

  First, print data transmitted from the host computer 1 is received by the I / F 11, and image data included in the received print data is transferred to the DRAM 16 by the DMA controller 12 and stored in the DRAM 16. The stored image data is read from the DRAM 16 by the DMA controller 12 at a predetermined timing and transferred to the data decompression circuit 13. Since the transferred image data is compressed as described above, the data decompression circuit 13 performs decompression processing, thereby generating video data. The generated video data is transmitted to the print engine 20 by the video controller 14 in synchronization with the vertical synchronization signal and horizontal synchronization signal from the print engine 20. The print engine 20 performs printing based on the transmitted video data, and forms an image on a print medium such as paper.

  A series of processing performed in the printer 2 is controlled by the CPU 15 in accordance with a program recorded in the ROM 17. FIG. 2 is a diagram conceptually showing the program recorded in the ROM 17. The printer 2 according to the present embodiment includes three programs (1) to (3) as shown in FIG. 2 in order to control the series of processes described above.

  The program (1) controls the timing at which the printer 2 receives image data from the host computer 1 and temporarily stores it in the DRAM 16 and then transfers the image data stored in the DRAM 16 to the print engine 20 side. This is so-called data transfer control. The program (2) controls paper feed processing (print medium supply processing) in the print engine 20 at the time of execution of printing. The paper feed process is started by a paper feed process start request issued by the program (1). First, the image data stored in the DRAM 16 is read and transferred to a data decompression circuit.

  The program (3) is a program for managing the program (2). Even when a request for starting a paper feed process by the program (1) is issued, the paper feed process for the previous page is still being performed. For example, the program (2) activated by the request for starting the paper feed process is put into a standby state by the program (3). Thereafter, when the paper feed process for the previous page is completed, the program (3) controls to start the next paper feed process in the standby state. In the printer 2, the three programs are stored in the ROM 17 and executed by the CPU 15. However, the printer 2 includes a plurality of ROMs and CPUs, and the three programs are any of the plurality of ROMs. And may be executed by any one of the plurality of CPUs.

  The printer 2 according to the present embodiment receives the data transfer process controlled by the program (1) among the processes described above, that is, receives and stores the print data, and sends it to the print engine 20 side at a predetermined timing. The data transfer process will be described in detail below. FIG. 3 is a flowchart illustrating an example of a data transfer processing procedure for print data for one page.

  First, with respect to the print data transmitted from the host computer 1, reception of print data of a page to be processed is started (step S10). FIG. 4 is a diagram for explaining print data for one page to be received. As described above, the print data for one page is composed of a header and image data. The image data representing an image is a band unit that is an area obtained by dividing one page at a predetermined interval in the height direction. Be treated. The image data divided for each band is hereinafter referred to as band data.

  In the example shown in FIG. 4, the band data is composed of CMYK four-color data. Depending on the order of transmission from the host computer 1 to the printer 2, two types of data shown in FIGS. 4A and 4B are provided. There is a configuration. FIG. 4A shows a configuration of print data received by the printer 2 in the case of performing transmission by so-called plane sequential transmission in which all band data is transmitted for each color for one page. In this case, for example, as shown in the figure, for one page, first, all C band data is received, and then all M band data, all Y band data, and all K band data are sequentially received. Receive data. This plane sequential transmission / reception is used when the print engine 20 performs a flying start with a 4-cycle page printer that executes printing processing for each color.

  On the other hand, FIG. 4B shows the print data received by the printer 2 in the case of performing so-called band sequential transmission in which band data of all colors constituting the image data is transmitted for each band. The configuration is shown. In such a case, for example, as shown in the figure, C band data, M band data, Y band data, and K band data in the first band are sequentially received. Band data is sequentially received for. This band sequential transmission / reception is used by a tandem page printer or the like that performs printing processing of each color in parallel in the print engine 20.

  In the example shown in FIG. 4, when one color image data in one band is set as one band data, the image data for one page is composed of n band data. The header added before the band data includes various control information. For example, the paper size at the time of printing, the number n of band data constituting the image data of one page, the timing of the flying start Is included, such as transfer processing start timing m. This transfer processing start timing is a timing at which the above-described program (1) issues a request to start the paper feed processing for the currently received page. Further, in this example, the timing is expressed by the number of received band data, and the transfer processing start timing m is that a paper feed processing start request should be made when m pieces of band data are received. This means that this value is set on the host computer 1 side. However, the transfer process start timing may be determined on the printer 2 side without setting the transfer process start timing on the host computer 1 side, that is, without including the value of m in the header.

  Returning to FIG. 3, when reception of print data is started for the page to be processed, the printer 2 first interprets the header (step S20). Then, after grasping the control information described above, it is determined whether or not the paper feed processing start timing, which is the timing for issuing the request for starting the paper feed processing, has been reached (step S30). In a normal case, there are few cases where the paper feed processing start timing is reached immediately after receiving the header, but when the timing is reached (Yes in step S30), the processing shifts to step S50 described later.

  On the other hand, if the paper feed processing start timing has not been reached (No in step S30), the reception of print data is continued and one band data is received (step S40). Thereafter, the process returns to step S30, and it is determined again whether or not the paper feed processing start timing has been reached. The steps S40 and S30 are repeated until the paper feed processing start timing is reached. For example, in the example shown in FIG. 4, if m = 20, it is determined that the paper feed processing start timing has been reached when 20 pieces of band data are received. If m = n, it is determined that the paper feed processing start timing has been reached when all band data for the page has been received. Further, when m = 0, it is determined that the paper feed processing start timing has been reached immediately after receiving the header.

  Note that the determination based on FIG. 4 described above is an example, and it is also possible to determine the paper feed processing start timing by another method. Also, the index for determining the paper feed processing start timing can be the reception time or the size of the received data, not the number of received band data. In such a case, step S40 is a process of data reception for a predetermined time or data reception of a predetermined size.

  In this way, when the paper feed process start timing is reached (Yes in step S30), first, it is checked whether or not all band data has been received for the page to be processed (step S50). If all band data has been received (Yes in step S50), a paper feed process start request is made for the page (step S60). And the process by the program (1) about the said page is complete | finished. In such a case, in response to the request for starting the paper feed process, the paper feed process for the page is started by the program (2), and the band data of the page is read from the DRAM 16. Since no band data is received by the DRAM 16, no underrun error occurs. Even if the paper feed process for the previous page is not completed and the paper feed process for the page is in a standby state by the program (3), all the band data of the page has been received. Does not occur.

  On the other hand, if all the band data has not been received (No in step S50), it is checked whether or not there is an undischarged page in the printer 2 (step S70). As described above, in the printer 2, the band data for the page is erased from the DRAM 16 after the printing process for each page is completed. More precisely, at the time when the paper discharge process for the printed page is completed for the page, the area of the DRAM 16 storing the band data of the page is released. This is to cope with a case such as a paper jam after the band data is transferred to the print engine 20 side. Therefore, the presence / absence of the undischarged page means whether or not the band data for the page before the page to be processed may be erased from the DRAM 16.

  If there is no page that has not yet been ejected (No in step S70), a paper feed process start request is made for the page (step S90). That is, a flying start is performed. Then, the reception of the remaining band data not yet received for the page is continued, and when all the band data is received (step S100), the processing by the program (1) for the page is ended. In such a case, the band data for the page prior to the page to be processed is in an erasable state from the DRAM 16, so in the normal case, data reception for the page is interrupted when the DRAM 16 becomes full. There is little risk of underrun errors even after flying starts.

  On the other hand, if there is a page that has not been ejected (Yes in step S70), the start timing of the paper feed process has already been reached, but the next one band data is not sent without issuing a request to start the paper feed process. Receive (step S80). And a process transfers to step S50 again. Note that this step S80 may be a process of data reception for a predetermined time or data reception of a predetermined size as in step S40.

  Thereafter, steps S80, S50, and S70 are repeated until all the band data is received for the page or until there is no undelivered page. In step S80, if the band data for the previous page cannot be erased from the DRAM 16 and data reception can no longer be continued, the processing is interrupted as described above. Then, the process is resumed after the discharge process for the previous page is completed. In such a case, in the subsequent step S70, there is no undelivered page, so that the process proceeds to step S90 and the flying start is performed.

  As described above, even when the paper feed processing start timing is reached, if there is a page that has not been ejected (Yes in step S70), the flying start is not performed. Will not interrupt and cause an underrun error.

  FIG. 5 is a diagram schematically illustrating a state in the DRAM 16 when the above-described processing is performed. As shown in FIG. 5A, the square shown in FIG. 5 schematically shows the capacity of the DRAM 16, and the data of the page to be processed is from the upper end of each nozzle of the system to the position indicated by aa. It shall have capacity.

  First, in the case of (A) in FIG. 5, when the data is received up to the position indicated by a for the target page, the paper feed processing start timing is reached, and there is no undelivered page. In such a case, the process proceeds to step S90 of FIG. 3 described above, and thus the flying start is performed at this timing.

  Next, in the case of FIG. 5B, when the data is received up to the position indicated by b for the target page, the paper feed processing start timing is reached and there is a page that has not been ejected. . Here, the data reception amount of the target page is the same as that shown in FIG. Therefore, in the flying start method that does not consider the previous page, the flying start is performed at this time point. However, as described above, the printer 2 does not start the flying and continues to receive data (start S80 in FIG. 3).

  Thereafter, the state where the data reception is continued without completing the paper discharge process for the previous page and the DRAM 16 is full is shown in FIG. When the reception of the band data is continued and the data is received up to the position indicated by c in the figure, the data reception is temporarily interrupted as described above. Thereafter, new data can be stored in the DRAM 16 after the previous page is discharged, so that data reception is resumed.

  FIG. 5D shows a state in which the data reception has been resumed. When the data reception is resumed and one band data is received and the position shown in FIG. 4D is reached, there is no page that has not been ejected. At this point, the process proceeds to step S90 in FIG. A start is made.

  The example shown in (E) of FIG. 5 is a case where the data size of the target page is smaller than the case of FIG. 5 (A), and the paper feed processing start timing is the same as in the case of (B) of FIG. Since the paper discharge process for the previous page has not ended yet, the data reception is continued without starting the flying, but when the data is received up to the position indicated by e in FIG. All data reception ends. Accordingly, the process proceeds to step S60 in FIG. 3, and at this time, a request to start the paper feed process is made.

  As described above, in the printer 2 according to the present embodiment, the discharge process for the previous page is not completed even if it is time to start flying without considering the previous page. Continues data reception without flying. Then, when the discharge processing of the previous page is completed, in other words, when there is no undischarged page, the flying start is performed. Accordingly, it is possible to eliminate an underrun error caused by the fact that data cannot be stored in the DRAM 16 after the flying start and data reception is interrupted. In addition, since the flying start is performed when and after the discharge processing of the previous page is completed, the effect of the flying start can be enjoyed. As described above, the present printer 2 can perform appropriate flying printing without causing a problem even in the case of continuous printing in which a plurality of pages are continuously processed.

  FIG. 6 is a diagram illustrating the state of the DRAM 16 when so-called 2-up printing is performed in the printer 2. Here, the 2-up printing means that two pages are printed on one printing medium (paper). When it is determined that there is a possibility of 2-up printing, even if reception of band data for the first page of 2-up printing is completed, the feeding of the band data for the second page is not started without starting the paper feed process. Control is performed to wait for reception. During the reception of the band data of the second page, the above-described processing described based on FIG. 3 is performed.

  First, after reception of band data for the second page is started, data reception is performed until the paper feed processing start timing set for the second page is reached (steps S30 and S40 in FIG. 3). The state in the DRAM 16 at this time is shown in FIG. In this state, all band data for the first page has been received, and the second page has been received up to the position indicated by A. Here, since the paper feed processing start timing set for the second page is reached, the process proceeds to step S50 in FIG. 3, but if the data reception of the second page has not yet been completed, Goes to step S70.

  Here, of course, since the paper discharge process has not been completed for the first page, the process proceeds to step S80, and the data reception of the second page is continued. That is, at this time, the paper feed process is not started. Thereafter, data reception is performed until the DRAM 16 is full, and a state as shown in FIG. When the position B is reached, data reception can no longer be continued and data reception is interrupted. Then, when a predetermined time elapses in this state, the printer 2 determines that the data for the second page is not ready, gives up 2-up printing, and switches to printing one page at a time. Therefore, after that, the paper feed process for only the first page is started, and when the paper discharge process for the first page is completed, the data reception for the second page is resumed. And when one band data is received based on step S80 of FIG. 3, it will be in the state as shown to (C) of FIG. When the position indicated by C is reached, the paper discharge process has already been completed for the first page, so it is determined that there is no undischarged page, and the process proceeds to step S90 in FIG. Is started. Accordingly, a flying start is performed for the second page.

  On the other hand, as described above, when data reception is continued after the state shown in FIG. 6A, if data reception for the second page is completed before the DRAM 16 is full, that is, If the data for the second page is completed at the position D shown in FIG. 6D, the paper feed process is started at this point in accordance with step S60 of FIG. In this case, 2-up printing is performed on the first page and the second page.

  As described above, in this printer 2, even when 2-up printing is possible and the flying timing is set, printing can be executed without causing an underrun error, and depending on the data size, 2-up printing can be performed. Also, for the second page when 2-up printing cannot be performed, the flying start can be performed, and the effect of the flying start can be obtained.

  Next, a specific example of determining whether or not the above-described paper feed processing start timing has been reached (step S30 in FIG. 3) will be described. FIG. 7 is a flowchart illustrating an example of a paper feed process start timing determination process. The processing content shown in FIG. 7 is a concrete implementation of step S30 in FIG. In this specific example, as shown in FIG. 4, the number m of bands at the paper feed (transfer) processing start timing is set on the host computer 1 side and is included in the header of the print data transmitted to the printer 2. It shall be.

  First, when the interpretation of the header (step S20) is completed after the start of reception of print data, it is checked whether or not m band data that is the set paper feed processing start timing have been received (step S31). The reception of band data (step S40) is repeated until m pieces of band data are received.

  When m pieces of band data are received (Yes in step S31), the printer 2 calculates a reception speed (step S32). FIG. 8 is a time chart for explaining the paper feed processing start timing. A solid line portion in (1) of FIG. 8 indicates a period from the start of reception of band data of the target page to reception of the m pieces of band data. The reception speed is calculated by dividing the data size S0 received during this time by the reception time T0 during this time.

  Next, the average size of the band data received up to this point is obtained (step S33). As described above, since the band data is transmitted after being compressed on the host computer 1 side, the size differs for each band data depending on the contents of the data. The average size of 1-band data is obtained by dividing the data size S0 received so far by m. In the example illustrated in FIG. 8, the number n of band data of the target page is 100, and the paper feed processing start timing m set in the header is 25. Therefore, in this example, S0 is divided by 25.

  Next, the size S1 of the remaining band data not yet received of the target page is predicted (step S34). The remaining data size S1 is obtained by multiplying the average size of the obtained one band data by the number of remaining band data. In the example shown in FIG. 8, the value of S0 ÷ 25 × (100−25) is S1. Then, a time T1 required to receive the obtained remaining data size S1 is predicted (step S35). Specifically, the reception time T1 is obtained by dividing the remaining data size S1 by the reception speed obtained in step S32.

Thereafter, the printer 2 compares the predicted reception time T1 with the time T2 for transferring one page of band data stored in the DRAM 16 to the print engine 20 (step S2).
36). More precisely, the transfer time T2 is a time when a paper feed processing start request is issued based on the program (1), and the paper feed processing by the program (2) is started without entering a standby state based on the request. This means the time from the start of reading one page of band data from the DRAM 16 to the end of reading. The transfer time T2 is a value obtained by multiplying the number of band data of one page by a constant, and can be easily obtained using the value of n included in the header of the print data.

  In the comparison between the reception time T1 and the transfer time T2, if the reception time T1 is shorter (Yes in step S36), the program 2 determines that the paper feed processing start timing has been reached at this time, and the processing is described above. Control goes to step S50. On the other hand, as shown in (2) of FIG. 8, if the transfer time T2 is shorter (No in step S36), it is determined that the paper feed processing start timing has not yet been reached, and the value of m is corrected (step S37). ). At this time, the value of m is naturally updated to a value larger than the previous value, but various methods can be used for this correction.

  As shown in (3) of FIG. 8, in the example of FIG. 8, at this time, the time when the reception time T1 is expected to be smaller than the transfer time T2 is determined as the time when 55 band data is received, for example. Is done. In such a case, this m ′ = 55 value can be corrected to a new m value. Further, the value of m can be corrected by adding a predetermined value regardless of m ′. In the example of FIG. 8, for example, 10 is added to m = 25, and the value of m is updated to 35. In the case of this method, after the value of m is updated, the predetermined value (for example, 10) is added every time it becomes No in step S36 again and the value needs to be updated.

  Furthermore, the value of m ′ may be compared with a value of 2m, that is, a value (m + m) obtained by further adding the initially set value of m, and updated to a smaller value. . In the example of FIG. 8, as shown in (3) of FIG. 8, since the value of 2m is smaller, the value of m is updated to 50. In this method, each time an update of the value of m is required, a value obtained by adding the value of m initially set (the value set in the header in this specific example) to the value of m at that time Then, the value of m ′ at that time is compared and the smaller value is selected.

  Thus, when the value of m is updated, the process proceeds to step S40, and reception of band data is performed until the updated number m of band data is received. When the updated m pieces of band data are received (Yes in step S31), the processing from step S32 described above is performed. Thereafter, the same processing is repeatedly executed until it is determined that the reception time T1 is smaller than the transfer time T2.

  As described above, in the specific example described with reference to FIG. 7, during reception of data, it is repeatedly determined whether or not the set paper feed processing start timing is appropriate based on the reception status until then. Checked. Accordingly, the flying start is performed based on the highly accurate paper feed processing start timing, and the risk of causing problems such as an underrun error is reduced. Further, in the m update process (step S37) described above, the value of m is increased at a stroke until the value of m ′, that is, the time when the reception time T1 is expected to be smaller than the transfer time T2 at that time. By not doing so, it is possible to start the flying start without any problem as soon as possible, and the throughput of the printer 2 can be improved. Usually, in the transmission processing of print data for one page from the host computer 1, in the first half, compression processing of data to be transmitted, storage processing in the host computer 1, and transmission processing to the printer 2 are performed in parallel. In the latter half, only the process of transmitting the stored data to the printer 2 is performed. Therefore, the data reception process in the printer 2 is also usually performed faster after the beginning of one page. As a result, the effect of checking the timing of flying start by updating to a value smaller than the value of m ′ described above can be obtained.

  As described above, by using the printer 2 according to the present embodiment, a flying start is performed in consideration of the previous page, and an underrun error caused by data reception being interrupted by the capacity of the DRAM 16 is prevented. Even in the case of continuous printing in which a plurality of pages are processed in succession, proper printing can be performed.

  The present invention can be applied to both a so-called 4-cycle page printer and a tandem page printer.

  The protection scope of the present invention is not limited to the above-described embodiment, but covers the invention described in the claims and equivalents thereof.

1 is a configuration diagram according to an embodiment of a printing apparatus to which the present invention is applied. FIG. 2 is a diagram conceptually showing a program recorded in a ROM 17. It is the flowchart which illustrated the procedure of the data transfer process. It is a figure for demonstrating the printing data for one page to receive. 2 is a diagram schematically illustrating a state in a DRAM 16. FIG. It is the figure which illustrated the state of DRAM16 at the time of performing 2-up printing. 6 is a flowchart illustrating an example of a process for determining a paper feed process start timing. 6 is a time chart for explaining a paper feed process start timing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Host computer, 2 Printer, 10 Controller, 11 I / F, 12 DMA controller (data transfer means), 13 Data decompression circuit, 14 Video controller, 15 CPU (data transfer means), 16 DRAM (data storage means), 17 ROM (data transfer means), 20 print engine

Claims (6)

A printing device that receives image data transmitted from a host device, and a print engine performs printing on a print medium based on the received image data,
Data storage means for storing the received image data;
A means for reading out image data stored in the data storage means and transferring the image data to the print engine side, wherein the data to the print engine side for the page before reception of the image data for one page is completed Flying start for starting transfer is a page on which the printing process is performed before the page that is the target of the flying start, and the print medium after printing has not yet been discharged from the printing apparatus And a data transfer unit configured to perform data transfer at a predetermined timing in a state where there is no undelivered page. In claim 1,
The predetermined timing of the flying start performed by the data transfer unit is a predetermined timing corrected during reception of the image data of the page that is the target of the flying start. apparatus. A printing device that receives image data transmitted from a host device, and print engine prints on a print medium based on the received image data,
Data storage means for storing the received image data;
A means for reading out image data stored in the data storage means and transferring the image data to the print engine side, wherein the page for which the image data is being received is a page on which the printing process is performed prior to the page. Whether or not it is time to start data transfer to the print engine side regardless of whether or not there is an undischarged page in which the print medium after printing has not yet been discharged from the printing apparatus. When it is determined that it is time to start the data transfer, if there is no undischarged page, the data transfer is started, and if there is an undischarged page, the data transfer is performed. The data reception is continued without starting, and the data transfer is started when the undelivered page runs out or after the data reception of the page is completed. Printing apparatus characterized by having a data transfer unit. A data transfer method for storing the stored image data to the print engine in a printing apparatus in which the image data transmitted from the host device is received and stored, and the print engine performs printing on a print medium based on the stored image data Because
Before the reception of the image data for one page is completed, a flying start for starting data transfer to the print engine for the page is performed before the page that is the target of the flying start. In a state where there is an undischarged page in which the print medium after printing has not yet been discharged from the printing apparatus, it is performed at a predetermined timing in a state where there is no undischarged page. Characteristic data transfer method. In claim 4,
The data transfer method according to claim 1, wherein the predetermined timing at which the flying start is performed is a predetermined timing corrected during reception of the image data of the page that is the target of the flying start. A data transfer method for storing the stored image data to the print engine in a printing apparatus in which the image data transmitted from the host device is received and stored, and the print engine performs printing on a print medium based on the stored image data Because
Whether there is an undelivered page for which the printing process is performed before the page for which the image data is being received and the print medium after printing has not yet been ejected from the printing apparatus Regardless of whether or not, a first step of determining whether it is a timing to start data transfer to the print engine side;
If it is determined in the first step that it is the timing to start the data transfer, if there is no undischarged page, data transfer to the print engine side is started and the undischarged page is started. If there is, the data reception is continued without starting the data transfer to the print engine side, and the printing is performed when the undelivered page runs out or after the data reception of the page is completed. And a second step of starting data transfer to the engine side.

Images