JP4816238B2 - Image forming apparatus, image forming method, and program - Google Patents

Description

  The present invention relates to an image forming apparatus, an image forming method, and a program for storing data in a page description language (PDL) format in a memory.

  In recent years, print data created by an external device such as a PC (Personal Computer), that is, data in a page description language (PDL) format represented by PostScript (registered trademark) or PCL (Printer Control Language) Is received via a network such as a LAN, and the received data is temporarily converted into intermediate format data (intermediate data) and stored in the memory, and the intermediate data stored in the memory is sequentially read and bitmapped. 2. Description of the Related Art Image forming apparatuses such as network type copiers, printers, and MFPs (Multi Function Peripherals) that perform printing after converting to data have become widespread.

  Such an image forming apparatus is required to have a high throughput with respect to an increase in the amount of data accompanying an increase in the printing process speed. If any error occurs, it is necessary to print again from the page where the error has occurred, so the data must be retained until the printing is completed. Furthermore, if there is not enough free space on the memory, new data cannot be stored on the memory and a memory over error has occurred. Therefore, there is a problem in that the memory capacity required for processing a large amount of data at a time increases and the cost increases.

  Therefore, there is a method to manage different types of data in a shared memory using a predetermined threshold and improve the memory usage efficiency, but a simple comparison result of whether or not the free capacity of the memory is equal to or greater than the threshold Accordingly, there is a problem that the processing is stopped until the free capacity of the memory can be secured to the threshold value or more, and the throughput is lowered.

In order to solve such problems, the work area of the storage buffer is changed based on jam recovery information indicating the validity / invalidity of jam recovery processing set in advance for each interface as a technology for efficiently using memory. Thus, a printing apparatus that improves printing efficiency is disclosed (see Patent Document 1).
JP 2004-82401 A

  However, in the conventional technique as described in Patent Document 1, the work area of the storage buffer is changed based on the jam recovery information set for each interface, regardless of the size of job data or the size of each page data. Since the memory area reserved for jam recovery is fixed, there is a problem that a useless memory area is generated when the data size is small.

  In view of the above problems, an object of the present invention is to provide an image forming apparatus, an image forming method, and a program capable of improving the efficiency of a memory and improving the throughput.

According to the first aspect of the present invention, there is provided sheet size acquisition means for acquiring a sheet size per page of page description language format data having information indicating a sheet size, the page description language format data, and the page description language. Bitmap data generating means for generating the bitmap format data based on the intermediate format data between the bitmap format data obtained by interpreting the format data, the intermediate format data and the bitmap Storage means having a shared storage area in which format data is stored according to a threshold value, and data in the intermediate format corresponding to the page description language format data acquired by the paper size acquisition means , The intermediate format data that has not been generated by the bitmap data generation means into the bitmap format data. In other words, the bitmap format data capacity for one page of the intermediate format data corresponding to the page description language format data having the maximum paper size acquired by the paper size acquisition means is set as the threshold value. When storing the intermediate format data in the shared storage area, if the area for storing the intermediate format data can be secured in the shared storage area, the intermediate format data is stored, and a bit for one page is stored. When the map format data is generated , the image forming apparatus includes: a control unit that deletes the intermediate data from which the bitmap format data is generated from the shared storage area. Yes.
Furthermore, a program for causing a computer to function the main means shown in the invention described in claim 1 is provided (the invention described in claim 9 ).

Invention according to claim 2, in the image forming apparatus according to claim 1, wherein the control means, the capacity of the bit map data of one page data of the intermediate format, generates the data of the intermediate format The calculation is based on the resolution of the image forming apparatus with respect to the paper size of the data in the original page description language format.
Furthermore, a program for causing the computer to function the main means shown in the invention described in claim 2 is provided (the invention described in claim 10 ).

A third aspect of the present invention is the image forming apparatus according to the first or second aspect , further comprising intermediate data generation means for generating the intermediate format data based on the image data, and the control means includes the intermediate data The threshold value is set when generation of the page description language format data for each page into intermediate format data by the generation means.
Furthermore, a program is provided for causing a computer to function the main means shown in the invention described in claim 3 (the invention described in claim 11 ).

According to a fourth aspect of the invention, in the image forming apparatus according to any one of claims 1 to 3, wherein, based on the data of the intermediate format of one page by the bit map data generating means When the bitmap format data for one page is generated and the intermediate format data is erased from the shared storage area, the threshold value is set.
Furthermore, a program for causing the computer to function the main means shown in the invention described in claim 4 is provided (the invention described in claim 12 ).

According to a fifth aspect of the present invention, there is provided a sheet size acquisition step of acquiring a sheet size per page of page description language format data having information indicating a sheet size, the page description language format data, and the page description language. Obtained by the bitmap data generation step for generating the bitmap format data based on the intermediate format data between the bitmap format data obtained by interpreting the format data and the paper size acquisition step. Of the intermediate format data corresponding to the page description language format data and not generated in the bitmap data by the bitmap data generation step, the paper size acquisition step The intermediate corresponding to the data in the page description language format with the maximum paper size acquired by Set the volume of data of Equation 1 page bitmap of the data, as the the threshold value of the shared storage region where the intermediate format of data and the bitmap data is stored according to the threshold, the When storing the intermediate format data in the shared storage area, if the area for storing the intermediate format data can be secured in the shared storage area, the intermediate format data is stored, and a bitmap for one page is stored. And a control step of erasing the intermediate data from which the bitmap format data was generated from the shared storage area when the format data is generated . .

According to a sixth aspect of the present invention, in the image forming method according to the fifth aspect , the control step is such that the capacity of the bitmap format data for one page of the intermediate format data is the generation of the intermediate format data. The calculation is based on the resolution of the image forming apparatus to which the image forming method is applied to the paper size of the original page description language format data.

Invention according to claim 7, in the image forming method according to claim 5 or 6, wherein the intermediate data generation step of generating data of the intermediate format based on the image data, wherein the control step, the intermediate data The threshold value is set when generation of the page description language format data for each page into intermediate format data is started in the generation step.

According to an eighth aspect of the present invention, in the image forming method according to any one of the fifth to seventh aspects, the control step is based on the intermediate format data for one page by the bitmap data generation step. When the bitmap format data for one page is generated and the intermediate format data is erased from the shared storage area, the threshold value is set.

According to the first, fifth , and ninth aspects of the present invention, since the threshold value of the shared storage area in which data of different formats is stored can be changed according to the paper size, the shared storage area in the storage unit can be changed. (Memory) can be made highly efficient, and throughput can be improved.

According to the first, fifth, and ninth aspects of the present invention, intermediate format data corresponding to the page description language format data from which the paper size has been acquired, and not generated in bitmap format data. Of the intermediate format data, the bit map format data capacity of one page of the intermediate format data corresponding to the page description language format data having the maximum paper size can be set as a threshold, so that the minimum While securing the capacity to store bitmap format data, it is possible to reduce the occurrence of wasted free space where intermediate format data cannot be saved, and to reduce the waiting time for free space where intermediate format data can be stored Therefore, it is possible to improve the efficiency of the shared storage area (memory) in the storage unit and improve the throughput.

According to the inventions of claims 2 , 6 , and 10 , the same effects as those of claims 1 , 5 , and 9 can be obtained, as well as the bitmap format data for one page of the intermediate format data. The capacity can be calculated based on the resolution of the image forming apparatus with respect to the paper size of the page description language format data that is the generation source of the intermediate format data.

According to the invention described in claim 3 , 7 , or 11 , the same effect as in claim 1 or 2 , 5 or 6 , 9 or 10 can be obtained. Since the setting can be changed when generation of data in the intermediate format is started as data in the intermediate format, the threshold can be changed as appropriate according to the state of processing of the data in the latest page description language format, and in the storage means The efficiency of the shared storage area (memory) can be improved.

According to the inventions described in claims 4 , 8 , and 12 , it is possible to obtain the same effect as any one of claims 1 to 3 , 5 to 7 , and 9 to 11 , and the threshold value is Since one page of bitmap format data is generated based on one page of intermediate format data and the intermediate format data is deleted from the shared storage area, the setting can be changed. The threshold value can be appropriately changed according to the state of the intermediate format data stored in the storage area (memory) of the memory, and the efficiency of the shared storage area (memory) in the storage means can be increased. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First, the configuration will be described.
FIG. 1 is a control block diagram of the image forming apparatus 1 in the present embodiment.
As shown in FIG. 1, the image forming apparatus 1 includes a control unit 10, an external IF (Inter Face) 11, an operation display unit 12, an image reading unit 20, and a print unit 30, and each unit is connected by a bus or the like. The external device 2 is communicably connected via the external IF 11.

  The image forming apparatus 1 reads an image from an original to be read (hereinafter referred to as an original), and forms a copy image on a recording medium such as a sheet as a processing target paper, a personal computer, or the like. This is a digital multifunction machine having a printer function and the like that receives image data from the external device 2 and forms and outputs an image on a recording medium based on the received image data.

  The control unit 10 includes a CPU (Central Processing Unit) 100, a ROM (Read Only Memory) 110, a RAM (Random Access Memory) 120, and the like, and develops various processing programs and data stored in the ROM 110 in the RAM 120. The operation of each part of the image forming apparatus 1 is centrally controlled based on the program. For example, in accordance with an instruction signal input from the operation display unit 12 or the external device 2, the copy mode, the print mode, and the scanner mode are switched, the processing program for each mode is read, and control such as copying, printing, and reading of image data is performed. Do.

  The CPU 100 interprets data in a page description language format (hereinafter referred to as PDL data) such as Postscript (registered trademark) or PCL in cooperation with the ROM 110 and the RAM 120, and the PDL data and bitmap format data (hereinafter referred to as PDL data). Intermediate format data (hereinafter referred to as intermediate data) is generated and stored in the shared storage area 123 in the RAM 120, and bitmap data is generated based on the intermediate data. And stored in the shared storage area 123 of the RAM 120. Further, when the CPU 100 stores intermediate data and bitmap data having different formats in the shared storage area 123, the CPU 100 performs storage management of the intermediate data and bitmap data using a threshold value.

  The intermediate data is data generated according to the characteristics of the objects (text data, graphics data, image data, etc.) included in the PDL data. For example, the intermediate data of text data and graphics data can include vector format data, and the intermediate data of image data can include image format data.

  Further, the CPU 100 obtains the paper size per page of the PDL data having page information indicating the paper size by cooperation of the ROM 110 and the RAM 120, and changes the setting of the threshold value of the shared storage area 123 according to the obtained paper size. Realize the function to do.

  Specifically, the CPU 100 starts generating PDL data as intermediate data for each page, or generates bitmap data for one page based on the intermediate data for one page, and the intermediate data is shared and stored. When deleted from the area 123, the intermediate data corresponding to the PDL data having the maximum paper size among the intermediate data of the PDL data from which the paper size has been acquired and not generated as bitmap data. A function of setting a capacity (hereinafter referred to as a guaranteed value) required when converted into bitmap data for one page as a threshold is realized.

  The guarantee value is calculated based on the paper size acquired by analyzing the page information of the PDL data that is the generation source of the intermediate data when the generation of the intermediate data is started from the PDL data for one page. Specifically, the guaranteed value is the resolution of the image forming apparatus 1 (the number of pixels in the vertical direction and the number of pixels in the horizontal direction of the paper size) corresponding to the acquired paper size, and the color of the developing device provided in the image forming apparatus 1 And the minimum compression rate.

  The number of colors of the developing device included in the image forming apparatus 1 is, for example, “4” in the case of the image forming apparatus 1 including four YMCK developing devices, and the image forming apparatus including three RGB developing devices. If it is 1, it is “3” and does not depend on whether the PDL data is a monochrome image or a color image, and is a unique value of the image forming apparatus 1 determined by the configuration of the image forming apparatus 1. .

  The minimum compression rate is statistically determined according to the data compression performance of the image forming apparatus 1, is the compression rate when the data compression rate is the lowest (the data cannot be compressed), and the PDL data It is a value unique to the image forming apparatus 1 regardless of the type (for example, text data, image data, etc.).

  Therefore, the guaranteed value is that the color and the minimum compression ratio of the developing device included in the image forming apparatus 1 are unique values of the image forming apparatus 1, and therefore the image forming apparatus for the sheet size of the PDL data that is the generation source of the intermediate data Can be calculated based on the resolution.

  The ROM 110 stores data processed by various programs such as various processing programs related to image formation, data related to image formation, and the like. In addition, the ROM 110 stores a program and data for realizing the present embodiment in cooperation with the CPU 100 and the RAM 120, a data receiving unit 111, an analysis unit 112, a bitmap data generation unit 113, and a print control unit 114. The threshold management unit 115 is included.

  The data receiving unit 111 stores a program and data for realizing a function of receiving PDL data input from the external device 2 via the external IF 11 and storing it in the spool area 122 in the RAM 120.

  The analysis unit 112 reads the PDL data stored in the spool area 122 in the RAM 120, generates intermediate data in a format between the read PDL data and the bitmap data, and the shared storage area 123 in the RAM 120. A program and data for realizing the function to be stored in are stored.

  The bitmap data generation unit 113 executes rasterization processing for generating bitmap data based on the intermediate data generated by the analysis unit 112 and stored in the shared storage area 123, and corresponds to the generated bitmap data. A program and data for realizing a function of deleting (releasing) intermediate data from the shared storage area 123 are stored.

  The print control unit 114 realizes a function of outputting the bitmap data generated by the bitmap data generation unit 113 to the print unit 30 that forms an image on a recording medium, and erasing (releasing) the output bitmap data. The program and data for making it memorize | store.

  The threshold value management unit 115 generates a page of bitmap data based on the intermediate data for one page when the generation of PDL data for each page is started as intermediate data, and the intermediate data is shared storage area When the data is erased from 123, the guaranteed value is the maximum of the intermediate data stored in the shared storage area 123 that is the intermediate data of the PDL data from which the paper size has been acquired and not generated as bitmap data. A program and data for realizing a function of setting a guaranteed value of intermediate data as a threshold value are stored.

  The ROM 110 may be a readable non-volatile storage medium, and may be configured with a magnetic or optical storage medium or a semiconductor memory. Further, the ROM 110 may be fixedly provided on the control board or the like, or may be detachably mounted.

  The RAM 120 has a development area 121, a spool area 122, and a shared storage area 123, and stores data processed by various programs such as data relating to image formation.

  The expansion area 121 is an area where various programs and data stored in the ROM 110 are expanded, and various data tables generated by executing the various programs and data, for example, a currently set shared storage area A threshold value 123, a table indicating the progress of each page, a data table of guaranteed values of intermediate data stored in the shared storage area 123, and the like are stored.

  The spool area 122 is an area for storing various data such as PDL data input from the external device 2 or the image reading unit 20.

  The shared storage area 123 is a shared storage area in which intermediate data and bitmap data are temporarily stored, and bitmap data is stored from the upper address in the shared storage area 123 toward the lower address, The intermediate data is stored in the shared storage area 123 from the lower address toward the higher address.

  In the shared storage area 123, if the areas in which the intermediate data and bitmap data can be stored are allowed indefinitely in the shared storage area 123, there is a deadlock state in which printing cannot be performed when there is no area for storing bitmap data. Arise. Therefore, in order to avoid this deadlock state, bitmap data can be stored without limitation in the shared storage area 123, and storage is limited by providing a threshold for intermediate data.

  The RAM 120 may be a readable / writable storage medium, and may be configured with an HDD (Hard Disk Drive), an MRAM (Magnetic Random Access Memory), or a flash memory, but is not limited thereto. Further, the RAM 120 may be fixedly provided on the control board or the like, or may be detachably mounted.

  The external IF 11 is a communication interface for connecting to a network N such as a network interface card (NIC) or a LAN such as a modem, and receives PDL data and the like from the external device 2. The received PDL data and the like are output to the control unit 10.

  The operation display unit 12 includes an LCD (Liquid Crystal Display), a touch panel provided to cover the LCD, an operation key group, and the like, and is used to input various setting conditions according to a display signal input from the control unit 10. Various setting screens and various processing results are displayed on the LCD, and operation signals input from the operation key group or the touch panel are output to the control unit 10.

The image reading unit 20 includes an automatic document feeder and a reading unit.
The automatic document feeder is called an ADF (Auto Document Feeder), and conveys documents stacked on the document tray one by one to a reading position of the reading unit.

  The reading unit is composed of a scanner equipped with a light source, lens, contact glass, image sensor, etc., and forms an image of reflected light of the light irradiated on the document and photoelectrically converts the image of the document to be printed. To the unit 30. Here, the image means not only image data such as graphics and photographs but also text data such as characters and symbols.

  The print unit 30 includes an image forming unit, a cleaning unit, an intermediate transfer belt, a paper feeding unit, a transport unit, and a fixing device.

  The image forming unit includes a charging device, an exposure device, a developing device, a primary transfer roller, a cleaning device, and the like disposed around the photosensitive drum, and the photosensitive drum charged by the charging device has a color (for example, from the exposure device). , Black (K)) is irradiated with light corresponding to the image data to form an electrostatic latent image, and the black (K) toner charged on the surface of the photosensitive drum on which the electrostatic latent image is formed by the developing device. And the electrostatic latent image is developed, and the photosensitive drum, to which the toner is adhered, is transferred to an intermediate transfer belt, which will be described later, while rotating at a constant speed to a transfer position where the primary transfer roller is disposed. After the toner is transferred to the intermediate transfer belt, residual charges, residual toner, and the like on the surface of the photosensitive drum are removed by a cleaning device.

  Note that the image forming unit is configured for each color when the image forming apparatus 1 forms an image according to image data of four colors of yellow (Y), magenta (M), cyan (C), and black (K). And an image forming unit.

  The intermediate transfer belt is a semiconductive endless belt that is suspended and supported by a plurality of rollers, and is rotationally driven along with the rotation of the rollers. The intermediate transfer belt is pressure-bonded to the photosensitive drum by the primary transfer roller. Each toner developed on the surface is transferred to the intermediate transfer belt at the transfer position by the primary transfer roller, and the toner of each color is sequentially transferred onto the recording medium at the transfer position by the secondary transfer roller.

  The paper feed unit includes a plurality of paper feed cassettes and a manual feed tray. In the feed cassette, a standard size recording medium identified in advance for each paper feed cassette size and paper type is accommodated, and the recording medium accommodated by the paper feed roller is transferred from the top to the transport unit one by one. Transport toward. The manual feed tray can be loaded with recording media of various nonstandard sizes each time according to the user's needs. The loaded recording medium detects the paper size and the sheet passing width, and the recording medium stacked by the paper feed roller is conveyed one by one from the top toward the conveying unit.

  The transport unit transports the recording medium transported from the paper tray and the manual feed tray to the secondary transfer roller through a plurality of intermediate rollers and registration rollers. By the secondary transfer roller, the toner image transferred to the intermediate transfer belt is collectively transferred onto the recording medium surface.

  Then, the toner image transferred onto the recording medium is thermally fixed on the recording medium onto which the toner image is transferred. The recording medium that has been subjected to the fixing process is sandwiched between paper discharge rollers and output onto a paper discharge tray.

  On the other hand, after the toner image is transferred to the recording medium by the secondary transfer roller, the residual toner is removed from the intermediate transfer belt obtained by electrostatically separating the recording medium with the curvature.

Next, the operation of this embodiment will be described.
First, a process until an image for one page is formed on a recording medium will be described with reference to FIGS.

  FIG. 2 shows a main flow diagram at the time of printing in the present embodiment. It is assumed that the operation shown in FIG. The processing module realized by the following steps S1 to S4 operates in a multitasking manner, so that a plurality of pages can be processed in parallel. However, for convenience of explanation, these steps S1 to S4 are performed in time series. Are listed.

  The CPU 100 receives the PDL data input via the external IF 11 by the data reception unit 111 and executes a data reception process for storing the PDL data in the spool area 122 (step S1).

  After the PDL data is saved in the spool area 122, the CPU 100 causes the analysis unit 112 to read the PDL data saved in the spool area 122, generate intermediate data, and execute an analysis process for saving the data in the shared save area 123. (Step S2).

  When the intermediate data for one page is stored in the shared storage area 123 by the bitmap data generation unit, the CPU 100 generates rasterized bitmap data for each band based on the intermediate data for one page from the shared storage area 123. The processing is executed to compress the bitmap data for each band and save it in the shared storage area 123 to generate bitmap data for one page (step S3).

  When the print control unit 114 stores the bitmap data for one page in the shared storage area 123, the CPU 100 reads out the bitmap data for one page from the shared storage area 123 and decompresses the bitmap data. The image is output to the print unit 30 and an image for one page is formed on the recording medium (step S4), and the process is terminated.

  FIG. 3 shows a flowchart of the analysis process executed in step S2. The operation shown in FIG. 3 shows an analysis process in which intermediate data for one page is generated and stored in the shared storage area 123, and is executed by the CPU 100 by the analysis unit 112.

  The CPU 100 analyzes the page information of the PDL data stored in the spool area 122, acquires the paper size indicated by the page information of the PDL data, and calculates the guaranteed value of the PDL data based on the acquired paper size Then, the calculated guaranteed value is stored in the development area 121 (step S11).

  The CPU 100 selects an object having PDL data (step S12), and generates intermediate data based on the selected object (step S13).

  Based on the capacity of the generated intermediate data, the CPU 100 executes storage area determination processing for determining whether or not there is an area in the shared storage area 123 that can store the intermediate data generated in step S12 (step S14).

  As a result of executing the storage area determination process, the CPU 100 determines whether or not it is determined that there is an area for storing the intermediate data (step S15).

  When the CPU 100 determines that there is no area for storing the intermediate data (step S15; No), the CPU 100 has an opportunity to determine whether there is an area in which the intermediate data can be stored, that is, data stored in the shared storage area 123. Wait until a signal (hereinafter referred to as a release signal) indicating an event in which (intermediate data or bitmap data) has been erased (released) from within the shared storage area 123 (step S16), and whether or not a release signal has been generated. Is discriminated (step S17).

  When it is determined that no release signal is generated (step S17; No), the CPU 100 returns to step S16, and when it is determined that a release signal is generated (step S17; Yes), the process returns to step S14.

  If the CPU 100 determines that there is an area for storing the intermediate data (step S15; Yes), the CPU 100 stores the intermediate data in the shared storage area 123, and determines whether generation of intermediate data for one page is completed. If it is determined (step S18) that it is determined that the generation of intermediate data for one page has not been completed (step S18; No), the process returns to step S12.

  When the CPU 100 determines that the generation of the intermediate data for one page has been completed (step S18; Yes), the process is terminated.

  FIG. 4 shows a flowchart of the bitmap data generation process executed in step S3. The operation shown in FIG. 4 shows bitmap data generation processing for generating bitmap data based on intermediate data for one page, and is executed by the CPU 100 by the bitmap data generation unit 113.

  The CPU 100 reads the intermediate data from the shared storage area 123 (step S21), and generates bitmap data in a preset unit (band unit) based on the read intermediate data. Hereinafter, the bitmap data generated in band units is referred to as band bitmap data (step S22).

  The CPU 100 stores the generated band bitmap data in the shared storage area 123 (step S23), and determines whether or not one page of bitmap data has been generated and stored in the shared storage area 123 (step S23). S24).

  When the CPU 100 determines that the bitmap data for one page has not been generated (step S24; No), the CPU 100 returns to step S21.

  When the CPU 100 determines that the bitmap data for one page has been generated (step S24; Yes), the CPU 100 erases the intermediate data from which the bitmap data for one page stored in the shared storage area 123 has been generated ( Release) (step S25).

  The CPU 100 generates a release signal indicating an event that the intermediate data has been deleted from the shared storage area 123 (step S26), and ends this process.

  FIG. 5 shows a flowchart of the printing process executed in step S4. The operation shown in FIG. 5 shows print processing for forming an image on a recording medium based on bitmap data for one page, and is executed by the CPU 100 by the print control unit 114.

  The CPU 100 reads bitmap data for one page from the shared storage area 123 and causes the printing unit 30 to output the bitmap data (step S31).

  The CPU 100 outputs bitmap data for one page to the printing unit 30, and whether or not an image corresponding to the output bitmap data is formed on a recording medium and discharged, that is, a bitmap for one page. It is determined whether or not the printing process corresponding to the data has been completed (step S32).

  If the CPU 100 determines that the printing process corresponding to the bitmap data for one page has not been completed (step S32; No), the CPU 100 returns to step S31.

  When the CPU 100 determines that the printing process corresponding to the bitmap data for one page has been completed (step S32; Yes), the bitmap data for one page for which the printing process stored in the shared storage area 123 has been completed. The bitmap data corresponding to is erased (released) (step S33).

  The CPU 100 generates a release signal indicating an event in which the bitmap data has been deleted from the shared storage area 123 (step S34), and ends this process.

  When the image forming apparatus 1 according to the present embodiment forms a plurality of pages of images on a plurality of recording media, the above-described processes (data examination process, analysis process, bitmap data generation process, and printing process) are performed. Multitasking that is executed concurrently is performed. When multitasking is performed, a priority order is set for each process, and the order of the processes to be executed is changed according to the set order. As an example of the priority order, the data reception process in step S1, the printing process in step S4, the bitmap data generation process in step S3, and the analysis process in step S2 are set in descending order of priority. An example can be given in which the processing to be formed is set to be prioritized.

  FIG. 6 shows a flowchart of PDL data analysis processing and bitmap data generation processing for one page when multitasking is performed. The operation shown in FIG. 6 is executed in the CPU 100 by the analysis unit 112, the bitmap data generation unit 113, and the threshold management unit 115. Therefore, when multitasking is performed, similar operations as shown in FIG. 6 are executed in parallel for each page.

  The CPU 100 analyzes the page information of the PDL data stored in the spool area 122, acquires the paper size of the PDL data, calculates the guaranteed value of the PDL data based on the acquired paper size, and calculates The guaranteed value is stored in the development area 121. Then, the CPU 100 sets the maximum guaranteed value among the guaranteed value of the intermediate data currently stored in the shared storage area 123 and the calculated guaranteed value as a threshold (step S41).

  That is, since the guaranteed value is calculated according to the paper size, setting the maximum guaranteed value means that the guaranteed value of the intermediate data corresponding to the PDL data of the maximum paper size is set as the threshold value. It becomes.

  When intermediate data is not stored in the shared storage area 123, the calculated guaranteed value is set as a threshold value.

  After the threshold is set, the CPU 100 causes the analysis unit 112 to generate intermediate data (step S42), and determines whether generation of intermediate data for one page has been completed (step S43). If the CPU 100 determines that the generation of intermediate data for one page has been completed (step S43; Yes), the CPU 100 proceeds to step S49.

  If the CPU 100 determines that the generation of intermediate data for one page has not been completed (step S43; No), that is, if the area for storing the intermediate data cannot be secured in the shared storage area 123, the CPU 100 stores the intermediate data in the shared storage area 123. It is determined whether intermediate data of PLD data of a page before the intermediate data is stored (presence of intermediate data of the previous page in the shared storage area 123) (step S44).

  When the CPU 100 determines that the intermediate data of the PLD data of the previous page is not stored in the shared storage area 123 (step S44; none), the CPU 100 proceeds to step S52.

  When the CPU 100 determines that the intermediate data of the PLD data of the page before the intermediate data is stored in the shared storage area 123 (step S44; present), the intermediate data for one page of the previous page is erased. It is determined whether or not (released) (step S45), and when it is determined that the intermediate data for one page of the previous page has not been erased (released) (step S45; No), the process returns to step S45, and the previous It waits until the intermediate data for one page is erased (released).

  When the CPU 100 determines that the intermediate data for one page of the previous page has been erased (released) (step S45; Yes), each intermediate data stored in the shared storage area 123 stored in the development area 121 With reference to the data table of guaranteed data, the maximum guaranteed value among the guaranteed values of intermediate data currently stored in the shared storage area 123 is set as a threshold (step S46).

  The CPU 100 restarts the generation of intermediate data by the analysis unit 112 (step S47), and determines whether the generation of intermediate data for one page is completed (step S48). If the CPU 100 determines that the generation of intermediate data for one page has been completed (step S48; Yes), the CPU 100 proceeds to step S49.

  After step S43 or step S48, that is, when generation of intermediate data for one page is completed and stored in the shared storage area 123, the CPU 100 stores the data in the shared storage area 123 by the bitmap data generation unit 113. One page of intermediate data is rasterized (step S49), the rasterized intermediate data for one page is erased (released) (step S50), and the process is terminated.

  If the CPU 100 determines that the generation of intermediate data for one page has not been completed (step S48; No), that is, if the area for storing the intermediate data cannot be secured in the shared storage area 123, the CPU 100 stores the intermediate data in the shared storage area 123. It is determined whether or not the intermediate data of the PLD data of the page before the intermediate data is stored (the presence or absence of the intermediate data of the previous page in the shared storage area 123) (step S51).

  When the CPU 100 determines that the intermediate data of the PLD data of the page before the intermediate data is stored in the shared storage area 123 (step S51; present), the CPU 100 returns to step S45.

  When the CPU 100 determines that the intermediate data of the PLD data of the page before the intermediate data is not stored in the shared storage area 123 (step S51; none), the generated data stored in the shared storage area 123 has been generated. The intermediate data is rasterized to generate bitmap data (step S52), and the rasterized intermediate data is released (step S53).

  Then, the CPU 100 restarts the generation of the intermediate data by the analysis unit 112 in the free area generated by the release of the intermediate data (step S54), and determines whether the generation of the intermediate data for one page is completed (step S55). ).

  When the CPU 100 determines that the generation of the intermediate data for one page is not completed (step S55; No), the CPU 100 returns to step S52.

  The operation from step S52 to step S54 is not to collectively rasterize intermediate data for one page, but to rasterize intermediate data that is less than one page stored in the shared storage area 123. This is called divided rasterization processing.

  When the CPU 100 determines that the generation of the intermediate data for one page has been completed (step S55; Yes), the CPU 100 executes the rasterization process of the incomplete rasterization process stored in the shared storage area 123 by the divided rasterization process. (Step S56), the rasterized intermediate data is erased (released) (step S57), and this process is terminated.

  FIG. 7 shows an example of the shared storage area 123 when multitasking is being performed, and will be described focusing on the generation of intermediate data for the second page.

  FIG. 7A shows an example of the shared storage area 123 in a state at the start of generation of the intermediate data of the second page. The shared storage area 123 shown in FIG. 7A is a guaranteed area G in which the guaranteed value of the first page is set as a threshold, intermediate data M1 of the first page of which generation has been completed and the paper size is A3 size, and intermediate data Has a storable free space E.

  The capacity of the guaranteed area G shown in FIG. 7A, that is, the threshold value, is calculated based on the A3 size paper size obtained by analyzing the page information of the PDL data of the first page, and is stored in the expanded area 121. The guaranteed value of the first page and the guaranteed value calculated based on the A4 size paper size obtained by analyzing the page information of the PDL data of the second page at the start of generation of the intermediate data of the second page Among them, the guaranteed value for the first page, which is the maximum guaranteed value, is set.

  FIG. 7B shows an example of the shared storage area 123 in a state where intermediate data for the second page is being generated and an area for storing the intermediate data cannot be secured in the shared storage area 123. The shared storage area 123 shown in FIG. 7B includes a guaranteed area G in which the guaranteed value of the first page is set as a threshold, intermediate data M1 of the first page that has been generated, and intermediate data of the second page that is being generated. Has M2.

  In order to secure a storage area for the intermediate data of the second page, each process is executed according to the priority. Here, since bitmap data for performing printing processing is not saved, bitmap data generation processing with the next highest priority is executed. Since the intermediate data M1 for the first page has already been generated, rasterization processing is executed, and bitmap data B1 for the first page is generated. An empty area is generated when the intermediate data of the first page generated as the bitmap data B1 of the first page is erased (released).

  FIG. 7C shows an example of the shared storage area 123 in a state where the intermediate data of the first page is erased (released), a free area is generated, and the capacity of the guaranteed area G is changed. The shared storage area 123 shown in FIG. 7C includes a guaranteed area G in which the guaranteed value of the second page is set as a threshold, a free area E1 generated by changing the setting of the guaranteed area G, and the middle of the first page. It has an empty area E2 generated by erasing (released) data and intermediate data M2 of the second page being generated.

  The capacity of the guaranteed area G shown in FIG. 7C, that is, the threshold value is the intermediate data stored in the shared storage area 123 when the intermediate data of the first page is erased (released). The guaranteed value for the second page, which is calculated based on the A4 size paper size obtained by analyzing the page information of the PDL data for the second page and stored in the development area 121, is set.

  Further, the empty area E1 generated by changing the capacity of the guarantee area G and the empty area E2 generated by erasing (releasing) the intermediate data of the first page are the intermediate data of the next page. It can be used as a storage area.

  As described above, according to the present embodiment, the PDL data having the maximum paper size among the intermediate data corresponding to the PDL data from which the paper size is acquired and not generated in the bitmap data. The guaranteed value of intermediate data corresponding to can be set as a threshold value, so that it is possible to reduce the generation of useless free space where intermediate data cannot be saved while ensuring the minimum capacity to store bitmap data. Therefore, it is possible to reduce the waiting time for the free space where the intermediate data can be stored. Therefore, since the threshold value of the shared storage area 123 can be changed according to the paper size, it is possible to improve the efficiency of the shared storage area 123 and improve the throughput.

Moreover, when PDL data for each page is started to be generated as intermediate data, or
When bitmap data for one page is generated based on the intermediate data for one page and the intermediate data is deleted from the shared storage area 123, the setting can be changed.
The threshold can be appropriately changed according to the state of processing of the latest PDL data, and the threshold can be appropriately changed according to the state of intermediate data stored in the shared storage area 123. The efficiency can be improved.

  In addition, this invention is not limited to the content of the said embodiment, In the range which does not deviate from the main point of this invention, it can change suitably.

FIG. 3 is a control block diagram of the image forming apparatus 1 in the present embodiment. It is a main flow figure at the time of printing in this embodiment. It is a flowchart of the analysis process performed in step S2. It is a flowchart of the bitmap data generation process performed in step S3. It is a flowchart of the printing process performed in step S4. FIG. 9 is a flowchart of PDL data analysis processing and bitmap data generation processing for one page when multitasking is performed. It is an example of the shared storage area 123 when multitasking is performed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 External apparatus 10 Control part 11 External IF
12 Operation Display Unit 20 Image Reading Unit 30 Print Unit 100 CPU
110 ROM
111 Data Reception Unit 112 Analysis Unit 113 Bitmap Data Generation Unit 114 Print Control Unit 115 Threshold Management Unit 120 RAM
121 Development area 122 Spool area 123 Shared storage area B1 Bitmap data E, E1, E2 for the first page Free area G Guaranteed area M1 Intermediate data for the first page M2 Intermediate data for the second page

Claims (12)

Paper size acquisition means for acquiring a paper size per page of data in a page description language format having information indicating the paper size;
Bitmap data generation for generating the bitmap format data based on intermediate format data between the page description language format data and the bitmap format data obtained by interpreting the page description language format data Means,
Storage means having a shared storage area in which the intermediate format data and the bitmap format data are stored according to a threshold;
Data in the intermediate format corresponding to the data in the page description language format acquired by the paper size acquisition unit, the intermediate format data not generated in the bitmap format data by the bitmap data generation unit Among the data, the capacity of the bitmap format data for one page of the intermediate format data corresponding to the page description language format data having the maximum paper size acquired by the paper size acquisition means is set as the threshold value. When the intermediate format data is stored in the shared storage area, if the area for storing the intermediate format data can be secured in the shared storage area, the intermediate format data is stored for one page. When the bitmap format data is generated, the above-mentioned medium that is the source of the bitmap format data is generated. And control means for erasing the data from the shared storage area,
Providing
An image forming apparatus. The control means includes
The capacity of the bitmap format data for one page of the intermediate format data is calculated based on the resolution of the image forming apparatus with respect to the paper size of the page description language format data from which the intermediate format data is generated. To do,
The image forming apparatus according to claim 1 . Comprising intermediate data generating means for generating data of the intermediate format based on the image data;
The control means includes
Setting the threshold when the intermediate data generating means starts generating the page description language format data for each page into intermediate format data;
The image forming apparatus according to claim 1 or 2 wherein. The control means includes
When the bitmap data generation unit generates the bitmap format data for one page based on the intermediate format data for one page, and the intermediate format data is deleted from the shared storage area, Setting a threshold,
The image forming apparatus according to any one of claims 1 to 3, characterized in. A paper size acquisition step of acquiring a paper size per page of page description language format data having information indicating the paper size;
Bitmap data generation for generating bitmap format data based on intermediate format data between the page description language format data and the bitmap format data obtained by interpreting the page description language format data Process,
Data in the intermediate format corresponding to the data in the page description language format acquired in the paper size acquisition step, the intermediate format data not generated in the bitmap format data in the bitmap data generation step Among the data, the bitmap format data capacity of one page of the intermediate format data corresponding to the page description language format data having the maximum paper size acquired by the paper size acquisition step is set as the intermediate format. And the bitmap format data are set as the threshold value of the shared storage area stored according to the threshold value , and the intermediate format data is stored in the shared storage area, the shared storage area If the area for storing the intermediate format data can be secured, the intermediate format data is stored and one page is stored. When a bitmap data is generated, and a control step of eliminating the intermediate data that is a generator of the data of the bitmap format from the shared storage area,
Including
An image forming method. The control step includes
An image forming apparatus that applies the image forming method to the page size of the page description language format data, which is the generation source of the intermediate format data, for the capacity of the bitmap format data for one page of the intermediate format data To calculate based on the resolution of
The image forming method according to claim 5 . Including an intermediate data generation step of generating data in the intermediate format based on the image data;
The control step includes
Setting the threshold when data in the page description language format for each page is started to be generated in intermediate format data by the intermediate data generation step;
The image forming method according to claim 5 or 6 . The control step includes
When the bitmap data generation step generates the bitmap format data for one page based on the intermediate format data for one page, and the intermediate format data is deleted from the shared storage area, Setting a threshold,
The image forming method according to any one of claims 5 7, characterized in. The computer,
Paper size acquisition means for acquiring a paper size per page of data in a page description language format having information indicating the paper size;
Bitmap data generation for generating bitmap format data based on intermediate format data between the page description language format data and the bitmap format data obtained by interpreting the page description language format data means,
Data in the intermediate format corresponding to the data in the page description language format acquired by the paper size acquisition unit, the intermediate format data not generated in the bitmap format data by the bitmap data generation unit Among the data, the bitmap format data capacity for one page of the intermediate format data corresponding to the page description language format data having the maximum paper size acquired by the paper size acquisition means is the intermediate format. And the bitmap format data are set as the threshold value of the shared storage area stored according to the threshold value , and the intermediate format data is stored in the shared storage area, the shared storage area If the area for storing the intermediate format data can be secured, the intermediate format data is stored and one page is stored. When bitmap data is generated, the control means for erasing said intermediate data that is a generator of the data of the bitmap format from the shared storage area,
Program to function as. The control means includes
The capacity of the bitmap format data for one page of the intermediate format data corresponds to the resolution of the image forming apparatus including the computer with respect to the paper size of the page description language format data that is the generation source of the intermediate format data. To calculate based on
The program according to claim 9 . Function as intermediate data generation means for generating data in the intermediate format based on the image data;
The control means includes
Setting the threshold when the intermediate data generating means starts generating the page description language format data for each page into intermediate format data;
The program according to claim 9 or 10, wherein: The control means includes
When the bitmap data generation unit generates the bitmap format data for one page based on the intermediate format data for one page, and the intermediate format data is deleted from the shared storage area, Setting a threshold,
The program according to any one of claims 9 to 11 , wherein:

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