JP2005231374A - Printer, method for managing memory of the printer and record medium recording program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer that can conduct high-quality printing with few image data memories. <P>SOLUTION: The printer consists of a generating means generating image data based on the received job data, image data memory memorizing image data generated with the above-mentioned generating means at each unit area, a second memory device in which a virtual memory area consisting of consecutive unit areas is formed, a memory managing means managing the processing about the virtual memory between the above-mentioned image data memory and the above-mentioned second memory device, and a providing means providing image data memorized in the above-mentioned image data memory to a printing engine. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technology of a page printer that performs printing after developing image data generated based on received job data in an image data memory.

  When receiving the print job data transmitted from the computer, the printer expands the image data generated according to the print job data on the image data memory. The printer develops image data for one page of paper, and then sequentially transfers the image data to the print engine to perform printing.

  As described above, the printer needs an image data memory capable of storing image data for one page. For example, in order to print on A4 paper at 600 dpi and monochrome, an image data memory of about 4 MB is required. Such an image data memory is generally constituted by a semiconductor storage device such as a DRAM.

  In recent years, with the development of computers, printers that realize high speed, high resolution, and full color have been required. In order to realize such a demand, it is necessary to mount a large-capacity image data memory, but there is a problem that it is difficult to realize in consideration of cost.

In addition, the image data memory is configured with a sufficient size in consideration of cost so that image data for one page can be stored. However, depending on the contents of the document, there may be a memory shortage state during image data generation. In order to deal with such a memory shortage state, the printer performs an image optimization process such as reducing the resolution when the memory shortage state occurs. For this reason, there has been a problem in that a printing result in which the printing quality is deteriorated as compared with the original printing state desired by the user is caused.
Accordingly, an object of the present invention is to provide a printer capable of performing high quality printing with a small amount of image data memory.

In order to solve the above problems, the present invention is specified as follows.
That is, the present invention provides a generation unit that generates image data based on received job data, an image data memory that stores the image data generated by the generation unit for each unit region, and a virtual unit that includes continuous unit regions. A secondary storage device in which a storage area is formed; storage management means for managing processing relating to virtual storage between the image data memory and the secondary storage device; and printing image data stored in the image data memory And a supply unit that supplies the engine.

  Here, the storage management means sequentially outputs the contents of the unit area in the virtual storage area to the unit area in the image data memory so that the supply means can supply the generated image data in order from the beginning. It is characterized by.

  Further, the storage management means sequentially outputs the contents of the unit areas in the virtual storage area to the unit areas in the image data memory that have been supplied by the supply means.

  Furthermore, the storage management means further comprises determination means for determining whether a unit area in the virtual storage area is assigned to any of the unit areas in the image data memory, and the generation means stores the image data. During generation, based on the determination by the determination means, the contents of the unit area in the image data memory are output to the unit area in the virtual storage area, and the contents of the unit area in the virtual storage area are output to the image. Output to the unit area in the data memory, and while the supplying means supplies the image data, the contents of the unit area in the virtual storage area are sequentially output to the unit area in the image data memory. .

  It is desirable that the memory size of the unit area corresponds to the memory size based on the printing bandwidth.

  On the other hand, the invention of the above can be grasped as a method invention. Specifically, the present invention stores image data generated based on received print job data in an image data memory, reads out the stored image data from the image data memory, and supplies it to a print engine. A management method comprising: forming a virtual storage area composed of continuous unit areas on a secondary storage device, and accessing the image data memory between the image data memory and the secondary storage device. A memory management method for a printer, characterized in that processing relating to storage is performed.

  Here, the processing relating to the virtual storage is characterized in that the contents of the unit area in the virtual storage area are sequentially output to the unit area in the image data memory so that the process can be sequentially supplied from the head portion of the image data.

  The processing relating to the virtual storage is characterized in that the contents of the unit areas in the virtual storage area are sequentially output to the unit areas in the image data memory for which the supply has been completed.

  Further, the processing relating to the virtual storage determines whether or not a unit area in the virtual storage area is assigned to any of the unit areas in the image data memory while the image data is being generated. When it is determined that the content of the unit area in the image data memory is output to the unit area in the virtual storage area, the content of the unit area in the virtual storage area is output to the unit area of the image data memory. While the image data is being supplied, the contents of the unit area in the virtual storage area are sequentially output to the unit area in the image data memory.

  The present invention can also be configured by a predetermined function realized by executing a program. Specifically, the present invention is a recording medium on which a program for causing a printer to realize a predetermined function is recorded. The program accesses the image data memory according to a physical address obtained based on a logical address. When a page fault occurs during the access, storage management means for performing processing related to virtual storage between the image data memory and the secondary storage device, and generating image data based on the received job data, Generation means for accessing the storage means in accordance with a logical address for expanding the generated image data in a virtual storage area, and reading out the image data expanded in the virtual storage area by accessing the storage management means in accordance with a logical address And a supply means for supplying to the print engine A program that symptoms may be recorded recording medium.

  The recording medium includes, for example, a memory such as a RAM and a ROM in addition to a hard disk (HD), a DVD-RAM, a flexible disk (FD), a CD-ROM, and the like. The printer refers to a printer including a so-called microcomputer or the like in which a so-called central processing unit such as a CPU or MPU performs predetermined processing by interpreting a program.

  According to the present invention, an inexpensive printer that can perform high-quality printing with a small amount of image data memory can be provided.

Next, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment] This embodiment is characterized in that image data memory is managed in a virtual storage using a hard disk device as a secondary storage device.

  FIG. 1 is a diagram illustrating a hardware configuration of a printer according to the present embodiment. In FIG. 1, a printer 1 according to the present embodiment includes a network interface 11 (hereinafter referred to as “network I / F”), a processor 12, a ROM 13, a RAM 14, I / O controllers 15 and 16, a print engine 17, and a hard disk device 18. Is provided. The printer 1 is connected to a computer (not shown) via a network N such as a LAN. The computer converts document data composed of graphic data, text data, and the like created by executing an application such as an editor or a word processor into print job data when printing is performed, and transmits it to the printer 1 via the network N. .

  The network I / F 11 receives print job data transmitted from the computer via the network N and holds it in an internal buffer (not shown). The processor 12 operates according to a predetermined program stored in the ROM 13 or RAM 14 and controls the entire printer 1. For example, the processor 12 generates image data based on print job data, and manages a virtual storage area (swap area) allocated to the RAM 14. Details of these will be described later.

  The RAM 14 has a program work area and a data work area. Further, the data work area is divided into an area for holding print job data and an area for holding image data generated based on the print job data. The RAM 14 is typically constituted by a DRAM. These areas may be logically divided or physically divided.

  The I / O controller 15 sends the image data transferred from the RAM 14 to the print engine 17 while monitoring the processing status of the print engine 17. The print engine 17 includes, for example, a paper feed mechanism and a print head, and performs printing on a print recording medium such as paper.

  The I / O controller 16 performs control for accessing the hard disk device. The I / O controller 16 performs input / output control between the RAM 14 and the hard disk device, for example, by a DMA function. The hard disk device 18 functions as a secondary storage device for the RAM 14. That is, the hard disk device 18 stores various programs executed by the processor 12 and stores data such as fonts and overlays. These data are loaded into the RAM 14 as needed under the control of the processor 12. Furthermore, in the present embodiment, the hard disk device 18 is used as a virtual storage area for the RAM 14.

  FIG. 2 is a diagram illustrating a functional configuration of the printer according to the present embodiment. The functional configuration of the printer according to the present embodiment is realized by a processor executing a predetermined program and operating in cooperation with other hardware.

  The communication unit 21 performs network communication with a computer. When the communication unit 21 receives the communication data related to the print job data, the communication unit 21 logically and physically converts the received communication data, extracts the print job data, and outputs the print job data to the job data memory 22.

  The image data generation unit 23 reads the print job data stored in the job data memory 22, interprets it, and generates image data. The image data is raster data corresponding to a print image for a print recording medium such as paper. The generated image data is expanded (stored) in the image data memory 24. In the present embodiment, in order to enable the image data generation unit 23 to develop image data having a size exceeding the physical space of the image data memory 24, the storage management unit 25 that manages processing related to virtual storage is used. The image data memory 24 is accessed.

  That is, the storage management unit 25 manages a virtual storage area allocated to the image data memory 24. In other words, the storage management unit 25 virtually looks like image data exceeding the physical space of the image data memory 24 is stored in the image data memory 24.

  More specifically, the storage management unit 25 includes a memory access unit 251, an address conversion unit 252, and a paging table unit 253. The memory access unit 251 divides and manages the image data memory 24 into fixed-length areas (predetermined unit areas) called pages, and assigns virtual storage areas allocated on the hard disk 26 to the predetermined unit areas. Page in (swap in) and page out (swap out). In the present embodiment, the size of the unit area is adjusted to one band width, and the number of unit areas is configured to be three pages (that is, three bands). Here, the band is a printing area determined by the number of dots in the main scanning direction and the number of dots in the sub-scanning direction. The address conversion unit 252 converts the input logical address into a physical address. The paging table unit 253 stores a paging table including information on whether or not a predetermined unit area indicated by a logical address exists in the image data memory unit 24.

  When the image data generation unit 23 completes generating image data for one page of the print recording medium (paper), the print control unit 27 sequentially reads the image data from the image data memory 24 via the storage management unit 25 and prints it. The image data is supplied to the print engine 28 according to the processing state of the engine 28. That is, when the print control unit 27 requests the storage management unit 25 to access the image data memory 24 in order to supply image data to the print engine 28, the storage management unit 25 performs virtual storage on the hard disk device 26 as necessary. A predetermined unit area is paged in the image data memory 24 from the storage area and output to the print control unit 27.

  FIG. 3 is a diagram for explaining the principle of virtual storage by the storage management unit 25 according to the present embodiment. Access to the image data memory 24 is performed according to a logical address. The logical address is composed of a logical page number and an in-page displacement. The logical page number is a number assigned to each area divided into predetermined unit areas on the virtual storage area. The in-page displacement is a displacement amount from the head position in a predetermined unit area. The paging table 253 includes a flag indicating whether or not the page (predetermined unit area) exists in the image data memory 24 in the entry corresponding to the logical page number, a flag indicating whether or not there is a write, and a physical page number And information such as a file name on the hard disk device.

  Note that the printer 1 according to the present embodiment is configured to take into account page-in and page-out when generating image data and deploying it on a virtual storage area, but supplies the image data to the print engine. In this case, the predetermined unit area is sequentially paged in without considering page-out.

  When the memory access unit 251 receives access to the image data memory 24 according to the logical address, the memory access unit 251 refers to the paging table unit 253 and checks the presence flag of the entry corresponding to the logical page number in the logical address. As a result, when it is determined that the image data memory 24 exists, the address conversion unit 252 calculates a physical address based on the physical page number and the intra-page displacement in the logical address, and the memory access unit This is sent to 251. On the other hand, when determining that it does not exist, the memory access unit 251 performs paging processing. That is, the memory access unit 251 determines a physical page on the image data memory 24 according to a predetermined eviction algorithm, and if the write flag of the page is true (there is a write), the contents are stored in the virtual storage area. The logical page to be read out is paged in at that position.

  Next, the operation of the printer 1 according to this embodiment will be described.

  FIG. 4 is a diagram for explaining the operation of the printer 1 according to the present embodiment. In the figure, the printer 1 initializes the paging table stored in the paging table unit 253 (STEP 41), and enters a print waiting state. When the printer 1 receives the print job data from the computer (STEP 42), the printer 1 sequentially interprets the received print job data, generates image data, and expands the image data in the logical space (STEP 43 and STEP 44). In other words, the printer 1 expands image data expanded on the virtual storage area according to the logical address to a physical address of the image data memory 24. In this case, when trying to access a unit area not allocated on the image data memory 24, a predetermined virtual storage process is performed. The printer 1 repeats the processing of STEP 42 to STEP 44 until image data for one page of the print recording medium is generated. When two or more copies of the print job data are printed, STEP 46 to STEP 49 are repeated for the corresponding number of copies after the second copy of the print target page.

  When the printer 1 determines that image data for one page has been generated (STEP 45), the printer 1 reads the image data memory from the image data memory 24 and supplies it to the print engine (STEP 46 and STEP 47). That is, the printer 1 develops the image data developed on the virtual storage area according to the logical address to the physical address of the image data memory 24, and sequentially supplies this to the print engine. In this case, when attempting to access a unit area not allocated on the image data memory 24, a predetermined virtual storage process is performed. The printer 1 repeats the processing of STEP 46 to STEP 47 until image data for one page is supplied to the print engine (STEP 48). The printer 1 repeats the above processing until all the received print job data is processed, that is, until printing for all pages is completed (STEP 49).

  Next, details of the virtual storage processing shown in FIG. 4 will be described with reference to FIGS.

  As described above, the printer 1 according to the present embodiment performs virtual storage processing in consideration of page-in and page-out when generating image data and deploying it on the virtual storage area (image data generation mode). When supplying image data to the print engine (image data supply mode), virtual storage processing is performed in consideration of only page-in without considering page-out.

  FIG. 5 is a diagram for explaining virtual storage processing of the printer according to the present embodiment. In the figure, the storage management unit 25 extracts the logical page number from the logical address (STEP 51), and refers to the entry of the paging table according to the logical page number (STEP 52). The storage management unit 25 checks whether the existence flag of the entry is true, that is, whether the logical page exists on the image data memory 24 (STEP 53). If it is determined in STEP 53 that the presence flag is true, the storage management unit 25 extracts the physical page number from the entry in the paging table (STEP 54). The storage management unit 25 calculates a physical address on the image data memory 24 based on the extracted physical page number and the in-page displacement in the logical address (STEP 55), and accesses the image data memory 24 (STEP 56). If the image data memory 24 is accessed, the storage management unit 25 changes the write flag of the accessed logical page in the paging table to true (STEP 57).

  On the other hand, if it is determined in STEP 53 that the presence flag is false, paging processing is performed (STEP 58). When the paging process occurs, access to the image data memory 24 is in a standby state until the page process is completed.

  FIG. 6 is a diagram for explaining the operation of the paging process in the image data generation mode. That is, the storage management unit 25 determines whether or not there is a free physical page (predetermined unit area) that can be paged in the image data memory 24 (STEP 61). When determining that there is no free physical page, the storage management unit 25 determines a physical page to be ejected according to a predetermined eviction algorithm, and saves the contents of this physical page in the virtual storage area of the hard disk device 26 ( (STEP 62). The eviction algorithm in this case is realized by, for example, an LRU (Least Recently Used) method. On the other hand, when it is determined in STEP 61 that there is a free physical page, or after page out is completed in STEP 62, the storage management unit 25 changes the contents of the logical page in the virtual storage area of the hard disk 26 to the physical in the image data memory 24. Write to the page (STEP 63). The storage management unit 25 changes the contents of the paging table in order to manage the logical page allocated to the physical page on the image data memory 24 (STEP 64).

  FIG. 7 is a diagram for explaining the operation of the paging process in the image data supply mode. The paging process in the image data supply mode is different from the paging process in the image data generation mode in that the contents of the physical page of the image data memory 24 due to page-out are not saved in the virtual storage area of the hardware device 26. That is, if the storage management unit 25 determines that there is no free physical page that can be paged in the image data memory 24 (STEP 71), the storage management unit 25 determines a physical page to be paged in according to a predetermined eviction algorithm. (STEP 72). In this case, the storage management unit 25 only determines a physical page to be paged in, and does not save the contents of the physical page in the virtual storage area of the hard disk 26. When the physical page to be paged in is determined, the storage management unit 25 writes the contents of the logical page on the virtual storage area of the hard disk 26 to the physical page on the image data memory 24 (STEP 73), and changes the contents of the paging table. (STEP 75).

  When the paging process shown in FIG. 6 or FIG. 7 is completed, the processes after STEP 54 shown in FIG. 5 are performed.

  Note that although the operation of the printer according to the present embodiment is configured sequentially, this is for the convenience of explanation and is not particularly limited. That is, as long as there is no contradiction in operation, the operation may be performed in parallel, or the order may be changed.

  Next, an operation example of the printer according to the present embodiment will be described with reference to FIGS. For example, assume that the printer 1 receives print job data that realizes a print image as shown in FIG. The print image is composed of a plurality of object frames. Graphic data and text data are assigned to each object frame. The computer generates print job data for each object frame and sequentially transmits it to the printer. In the figure, the circled numbers indicate the order in which the printer received the print job data.

  First, when the print job data 1 is received, the printer 1 interprets the print job data 1 to generate image data, and develops the image data on a predetermined logical page in the virtual storage area (FIG. 9A). That is, the storage management unit 25 expands the physical pages (physical page numbers 1 and 2) on the image data memory 24. Next, when the print job data 2 is received, one page is expanded to an empty page (physical page number 3), and the remaining pages are determined according to a predetermined eviction algorithm, for example, the contents of the physical page number 2 After page-out, it expands ((b) in the figure).

  Finally, when print job data 3 is received, the contents of physical page number 1 determined according to a predetermined eviction algorithm are saved in the virtual storage area. Then, the printer 1 assigns the page-out page (physical page number 1) to a logical page, generates image data based on the print job data 3, and develops the image data ((c) in the figure).

  When the generation of the image data is completed, the printer 1 sequentially expands logical pages on the virtual storage area into physical pages on the image data memory 24 as shown in FIG. 10 ((a) in FIG. 10). In this case, the contents of the physical page on the image data memory 24 are sequentially expanded so as to be overwritten without being saved in the hard disk 26 ((b) in the figure).

  As described above, according to the present embodiment, the generated image data can be expanded in the virtual storage area of the hard disk device. That is, image data having a size exceeding the physical space of the image data memory can be handled.

  Therefore, it does not fall into a memory shortage state, and it is not necessary to perform image optimization processing such as lowering the resolution, so that the original print quality desired by the user can be provided.

  Further, even when dealing with a large amount of image data that realizes high resolution and full color, it is not necessary to install an image data memory corresponding to the image data memory in the printer. Therefore, since a printer can be configured using a hard disk having a lower cost per bit than the image data memory, a printer with high print quality can be realized at low cost.

  Furthermore, according to the present embodiment, when supplying image data to the print engine, the contents in the image data memory are not saved in the hard disk device, but are sequentially read out from the hard disk device to the image data memory. Therefore, the overhead due to the virtual storage process can be reduced as much as possible. As a result, a printer capable of high-speed printing and high-quality printing can be realized with a small image data memory.

  Further, according to the present embodiment, the unit area size (physical page size) on the image data memory and the print band size correspond to each other. Can be supplied to the printing engine twice. For this reason, the overhead due to the virtual storage process can be eliminated as much as possible, and an efficient operation can be realized.

  [Second Embodiment] This embodiment is characterized in that a job data memory and an image data memory are managed in a virtual storage by using a hard disk device as a secondary storage device.

  FIG. 11 is a diagram illustrating a functional configuration of the printer 1 according to the present embodiment. In the figure, the same reference numerals are given to the same function realizing means as in the first embodiment. That is, the printer 1 according to the present embodiment is configured to always access the job data memory and the image data memory via the storage management unit 25.

  When the communication unit 21 receives the communication data related to the print job data, the communication unit 21 logically and physically converts it to extract the print job data, and sends it to the storage management unit 25. The storage management unit 25 manages virtual storage processing as in the above embodiment. That is, the storage management unit 25 converts the print job data expanded on the virtual storage area according to the logical address into a physical address of the job data memory 22 and expands it. In this case, when attempting to access a unit area not allocated on the job data memory 22, a predetermined virtual storage process is performed.

  The other function realizing means is the same as that in the above embodiment, and the description thereof is omitted.

  As described above, according to the present embodiment, print job data having a size exceeding the physical space of the job data memory can be handled. This is particularly effective when receiving a plurality of print job data at once.

1 is a diagram illustrating a hardware configuration of a printer according to a first embodiment. 1 is a diagram illustrating a functional configuration of a printer according to a first embodiment. Diagram for explaining the principle of virtual memory The figure for demonstrating the operation | movement of the printer which concerns on 1st Embodiment. The figure for explaining the operation of the virtual memory processing The figure for demonstrating the paging process in image data generation mode The figure for demonstrating the paging process in image data supply mode The figure which shows the printing image for demonstrating the operation example of a printer The figure which shows the operation example of the printer in image data generation mode The figure which shows the operation example of the printer in image data supply mode The figure which shows the function structure of the printer which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printer; 21 ... Communication part; 22 ... Job data memory; 23 ... Image data generation part; 24 ... Image data memory; 25 ... Storage management part; 26 ... Hard disk drive;

Claims (3)

Generating means for generating image data based on the received job data;
An image data memory for storing the image data generated by the generating means for each unit area;
A secondary storage device in which a virtual storage area composed of continuous unit areas is formed;
Storage management means for managing processing related to virtual storage between the image data memory and the secondary storage device;
Supply means for supplying image data stored in the image data memory to a print engine;
The storage management means further comprises determination means for determining whether a unit area in the virtual storage area is allocated to any of the unit areas in the image data memory, and the generation means generates the image data. While the content of the unit area in the image data memory is output to the unit area in the virtual storage area based on the determination by the determination means, and the content of the unit area in the virtual storage area is output to the image data memory A printer configured to be capable of executing a process of outputting to a unit area. A memory management method for a printer that stores image data generated based on received print job data in an image data memory, reads the stored image data from the image data memory, and supplies the image data to a print engine.
Forming a virtual storage area composed of continuous unit areas on a secondary storage device and performing a process related to virtual storage between the image data memory and the secondary storage device when accessing the image data memory; With
During the generation of the image data, the step determines whether a unit area in the virtual storage area is allocated to any of the unit areas in the image data memory, and determines that the unit area is allocated. And outputting the contents of the unit area in the image data memory to the unit area in the virtual storage area and outputting the contents of the unit area in the virtual storage area to the unit area of the image data memory. A memory management method for a printer. A recording medium storing a program for causing a printer to realize a predetermined function, wherein the program accesses an image data memory according to a physical address obtained based on a logical address, and a page fault occurs during the access A storage management means for performing processing relating to virtual storage between the image data memory and the secondary storage device, generating image data based on the received job data, and storing the generated image data in a virtual storage area Generating means for accessing the storage management means in accordance with a logical address for developing the image data; and supplying means for accessing the storage management means in accordance with a logical address to read out image data developed in the virtual storage area and supplying the image data to the print engine The storage management means includes the raw While the generation means accesses the storage management means, the contents of the unit area in the image data memory are output to the unit area in the virtual storage area, and the contents of the unit area in the virtual storage area are output in the image data memory. A recording medium on which a program is recorded, which is configured to be capable of executing processing to be output to a unit area.

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