JP2013052615A - Image forming apparatus, program and method for controlling drawing processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption, while maintaining productivity of an image forming output in an image forming apparatus which can execute drawing processing by hardware and software.SOLUTION: An image forming apparatus includes a hardware drawing processing control part 212 which obtains determination information indicative of a content of an image to formed and output according to display list creation and determines whether the drawing processing should be executed by a hardware accelerator 230 based on HA determination condition information determined according to PPM of a print engine 160 and a processing amount of the drawing processing determined based on the obtained determination information.

Description

  The present invention relates to an image forming apparatus, a drawing process control program, and a drawing process control method, and more particularly to control of image processing in an image forming apparatus.

  In recent years, there has been a tendency to digitize information, and image processing apparatuses such as printers and facsimiles used for outputting digitized information and scanners used for digitizing documents have become indispensable devices. Such an image processing apparatus is often configured as a multifunction machine that can be used as a printer, a facsimile, a scanner, or a copier by providing an imaging function, an image forming function, a communication function, and the like.

  Among such image processing apparatuses, in a printer used to output digitized information, image processing (hereinafter referred to as image processing) for generating drawing information for the print engine to execute image formation output based on the input image information. , A drawing process) is performed. This image processing is executed not only by dedicated hardware, but also by operation means such as a CPU (Central Processing Unit) operating according to software.

  On the other hand, in operation control of the apparatus, control with reduced power consumption as much as possible is desired. For example, in order to keep the power consumption of the image forming apparatus below a certain level, a method of measuring the environment of the apparatus and changing the intermediate language before executing the drawing process according to the measurement result has been proposed (for example, Patent Document 1). reference).

  In an image forming apparatus that can perform drawing processing by hardware and software as described above, generally, in order to reduce the time required for drawing processing as much as possible, the parallelism of processing of hardware and software is improved, In general, control is performed so that a standby time does not occur in either one of hardware and software.

  However, there is a limit to the number of sheets that can be output per unit time in a print engine that is an image forming unit that executes image forming output in the image forming apparatus. This is defined as, for example, PPM (Page Pre Minute). Then, by speeding up the drawing process beyond this PPM, even if the drawing process for the next page and subsequent drawing information is completed while the print engine is executing the image forming output of a certain page, the generated drawing The information is held in the storage medium and waits until the image forming output being executed by the print engine is completed.

  Such a state is a state where the maximum PPM is exhibited by the print engine, but is also a state where the drawing process is unnecessarily accelerated. The power consumed by the hardware that executes the rendering process for speeding up the rendering process is wasted power consumption.

  Therefore, if the processing load of the rendering process is low and the PPM of the print engine can be exhibited by the rendering process by software, the hardware stops the power supply without executing the rendering process, thereby saving power. It is preferable to aim for. In other words, it is desirable to optimize the distribution ratio of processing between hardware and software in consideration of the speed of necessary drawing processing rather than considering only high-speed drawing processing.

  On the other hand, in the technique disclosed in Patent Document 1, reduction of power consumption is considered, but the viewpoint of exhibiting the PPM of the print engine and maintaining the productivity of image formation output is not considered. .

  The present invention has been made in consideration of the above circumstances, and an object of the present invention is to reduce power consumption while maintaining productivity of image forming output in an image forming apparatus capable of performing drawing processing by hardware and software. .

  In order to solve the above problems, one aspect of the present invention is an image forming apparatus capable of executing image processing for executing image forming output by hardware and software, and obtained based on a page description language. Based on the drawing command, a graphic information generating unit that generates graphic information in which information is gathered for each graphic to be drawn, and drawing information for the image forming unit to execute image formation output are included in the generated graphic information. A drawing information generation unit that executes drawing processing generated based on software processing, a drawing information generation circuit that executes the drawing processing as hardware, and a drawing processing control that controls execution of pre-drawing processing by the drawing information generation circuit The drawing processing control unit obtains output content information indicating the content of an image to be imaged and output in response to the generation of the graphic information. A reference value determined according to the number of images that can be imaged and output per unit time by an image forming unit that executes image forming output, and a processing amount of the drawing process that is determined based on the acquired output content information Based on this, it is determined whether or not the drawing processing by the drawing information generation circuit is necessary.

  Another aspect of the present invention provides an image forming output in an image forming apparatus including a drawing information generating circuit that executes image processing for executing image forming output as hardware and a drawing information generating unit that executes by software processing. Is a drawing processing control program for controlling the generation of drawing information for executing, and generates figure information in which information is collected for each figure to be drawn based on a drawing command obtained based on a page description language A step of acquiring output content information indicating the content of an image to be imaged and output according to the generation of the graphic information, and an image forming unit that executes the image forming output is capable of image forming output per unit time Based on the reference value determined according to the number of sheets and the processing amount of the drawing process determined based on the acquired output content information, Possible to execute the steps in the image forming apparatus determines execution necessity of the drawing process by the information generating circuit and said.

  According to still another aspect of the present invention, an image forming apparatus includes: a drawing information generation circuit that executes image processing for executing image formation output as hardware; and a drawing information generation unit that executes software processing. A drawing processing control method that controls the generation of drawing information to execute output, and generates graphic information that summarizes information for each figure to be drawn based on drawing commands obtained based on the page description language In response to the generation of the graphic information, output content information indicating the content of the image to be imaged and output is acquired, and the image forming unit that executes the image forming output responds to the number of images that can be imaged and output per unit time. The drawing information generation circuit determines the drawing processing amount based on the reference value determined in accordance with the acquired output content information. Characterized by determining whether or not execution of the process.

  According to the present invention, in an image forming apparatus that can perform drawing processing by hardware and software, it is possible to reduce power consumption while maintaining productivity of image forming output.

1 is a block diagram illustrating a hardware configuration of an image forming apparatus according to an embodiment of the present invention. 1 is a diagram illustrating a functional configuration of an image forming apparatus according to an embodiment of the present invention. It is a figure which shows the function contained in the image process part which concerns on embodiment of this invention. It is a figure which shows the function structure of the drawing core module which concerns on embodiment of this invention, and a hardware accelerator. It is a flowchart which shows operation | movement of the hardware drawing process control part which concerns on embodiment of this invention. It is a figure which shows the example of the judgment information which concerns on embodiment of this invention. It is a figure which shows the example of HA judgment condition information which concerns on embodiment of this invention. It is a figure which shows the relationship between productivity of a print engine and drawing process time in the embodiment and comparative example of the present invention. It is a figure which shows the order of the drawing process which concerns on embodiment of this invention. It is a figure which shows the example of HA judgment condition information which concerns on other embodiment of this invention. It is a figure which shows the example of HA judgment condition information which concerns on other embodiment of this invention. It is a flowchart which shows HA judgment operation | movement which concerns on other embodiment of this invention. It is a figure which shows the function structure of the drawing core module which concerns on other embodiment of this invention, and a hardware accelerator. It is a figure which shows the example of HA judgment condition information which concerns on other embodiment of this invention. It is a figure which shows the example of HA judgment condition information which concerns on other embodiment of this invention. It is a flowchart which shows HA judgment operation | movement which concerns on other embodiment of this invention.

Embodiment 1 FIG.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present exemplary embodiment, an image forming apparatus as an MFP (Multi Function Peripheral) including functions of a printer, a scanner, a copier, and the like will be described as an example.

  FIG. 1 is a block diagram illustrating a hardware configuration of an image forming apparatus 1 according to the present embodiment. As shown in FIG. 1, the image forming apparatus 1 according to the present embodiment includes an engine related to image forming output in addition to the same configuration as an information processing terminal such as a general server or a PC (Personal Computer). That is, the image forming apparatus 1 according to the present embodiment includes a CPU (Central Processing Unit) 10, a RAM (Random Access Memory) 20, a ROM (Read Only Memory) 30, an engine 40, a HDD (Hard Disk Drive) 50, and an I / O. F60 is connected via the bus 90. Further, an LCD (Liquid Crystal Display) 70 and an operation unit 80 are connected to the I / F 60.

  The CPU 10 is an arithmetic device and controls the operation of the entire image forming apparatus 1. The RAM 20 is a volatile storage medium capable of reading and writing information at high speed, and is used as a work area when the CPU 10 processes information. The ROM 30 is a read-only nonvolatile storage medium and stores a program such as firmware. The engine 40 is a mechanism that actually executes image formation in the image forming apparatus 1. The engine 40 includes a print engine for executing image formation output, a scanner unit for reading a document, and a hardware accelerator for generating image information for the print engine to execute image formation output.

  The HDD 50 is a non-volatile storage medium that can read and write information, and stores an OS (Operating System), various control programs, application programs, and the like. The I / F 60 connects and controls the bus 90 and various hardware and networks. The LCD 70 is a visual user interface for the user to check the state of the image forming apparatus 1. The operation unit 80 is a user interface for a user to input information to the image forming apparatus 1 such as a keyboard and a mouse.

  In such a hardware configuration, a program stored in a recording medium such as the ROM 30, the HDD 50, or an optical disk (not shown) is read into the RAM 20, and the software control unit is configured by the CPU 10 performing calculations according to those programs. . A functional block that realizes the functions of the image forming apparatus 1 according to the present embodiment is configured by a combination of the software control unit configured as described above and hardware.

  Next, the functional configuration of the image forming apparatus 1 according to the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram illustrating a functional configuration of the image forming apparatus 1 according to the present embodiment. As shown in FIG. 2, the image forming apparatus 1 according to the present embodiment includes a controller 100, an ADF (Auto Document Feeder) 110, a scanner unit 120, a paper discharge tray 130, a display panel 140, and a paper feed table. 150, a print engine 160, a paper discharge tray 170, and a network I / F 180.

  The controller 100 includes a main control unit 101, an engine control unit 102, an input / output control unit 103, an image processing unit 104, and an operation display control unit 105. As shown in FIG. 2, the image forming apparatus 1 according to the present embodiment is configured as a multifunction machine having a scanner unit 120 and a print engine 160. In FIG. 2, the electrical connection is indicated by solid arrows, and the flow of paper is indicated by broken arrows.

  The display panel 140 is an output interface that visually displays the state of the image forming apparatus 1 and is an input when the user directly operates the image forming apparatus 1 or inputs information to the image forming apparatus 1 as a touch panel. It is also an interface (operation unit). The network I / F 180 is an interface for the image forming apparatus 1 to communicate with other devices via the network, and an Ethernet (registered trademark) or USB (Universal Serial Bus) interface is used.

  The controller 100 is configured by a combination of software and hardware. Specifically, a control program such as firmware stored in a ROM 30, a nonvolatile memory, and a nonvolatile recording medium such as an HDD 50 or an optical disk is loaded into a volatile memory (hereinafter referred to as a memory) such as a RAM 20, and the CPU 10 The controller 100 is configured by a software control unit configured by performing an operation according to the program and hardware such as an integrated circuit. The controller 100 functions as a control unit that controls the entire image forming apparatus 1.

  The main control unit 101 plays a role of controlling each unit included in the controller 100, and gives a command to each unit of the controller 100. The engine control unit 102 serves as a drive unit that controls or drives the print engine 160, the scanner unit 120, and the like. The input / output control unit 103 inputs a signal or a command input via the network I / F 180 to the main control unit 101. The main control unit 101 also controls the input / output control unit 103 to access other devices via the network I / F 180.

  The image processing unit 104 generates drawing information based on the print information included in the input print job, under the control of the main control unit 101. The drawing information is information for drawing an image to be formed in the image forming operation by the print engine 160 as an image forming unit. The print information included in the print job is information converted into a format that can be recognized by the image forming apparatus 1 by a printer driver installed in an information processing apparatus such as a PC. In the present embodiment, PDL ( This is information described by Page Description Language. In other words, the print information is page information in which information on a page to be imaged and output is described. In this embodiment, the case where PDL is used as the page description language is taken as an example, but another language may be used.

  The image processing unit 104 is realized by a hardware accelerator as described above and software configured by the CPU 20 performing calculations according to a program. Thus, by operating hardware and software in parallel, the above-described drawing information generation can be completed with high efficiency in a short time.

  On the other hand, it is meaningless to generate the drawing information faster than the productivity of the print engine 160, that is, PPM (Page Per Minute). The time required for generating the drawing information is not constant because it varies depending on the contents of the images constituting each page. In view of such circumstances, the gist of the present embodiment is to switch the use of the hardware accelerator in accordance with the content of the image to be output. The function of the image processing unit 104 will be described in detail later. The operation display control unit 105 displays information on the display panel 140 or notifies the main control unit 101 of information input via the display panel 140.

  When the image forming apparatus 1 operates as a printer, first, the input / output control unit 103 receives a print job via the network I / F 180. The input / output control unit 103 transfers the received print job to the main control unit 101. When receiving the print job, the main control unit 101 controls the image processing unit 104 to generate drawing information based on the print information included in the print job.

  When drawing information is generated by the image processing unit 104, the engine control unit 102 executes image formation on a sheet conveyed from the paper feed table 150 based on the generated drawing information. That is, the print engine 160 functions as an image forming unit. As a specific mode of the print engine 160, an image forming mechanism using an ink jet method, an image forming mechanism using an electrophotographic method, or the like can be used. The document on which the image has been formed by the print engine 160 is discharged to the discharge tray 170.

  When the image forming apparatus 1 operates as a scanner, the operation display control is performed according to a user operation on the display panel 140 or a scan execution instruction input from an information processing terminal for an external client via the network I / F 180. The unit 105 or the input / output control unit 103 transfers a scan execution signal to the main control unit 101. The main control unit 101 controls the engine control unit 102 based on the received scan execution signal.

  The engine control unit 102 drives the ADF 110 and conveys the document to be imaged set on the ADF 110 to the scanner unit 120. Further, the engine control unit 102 drives the scanner unit 120 and images a document conveyed from the ADF 110. If no original is set on the ADF 110 and the original is set directly on the scanner unit 120, the scanner unit 120 images the set original according to the control of the engine control unit 102. That is, the scanner unit 120 operates as an imaging unit.

  In the imaging operation, an imaging element such as a CCD included in the scanner unit 120 optically scans the document, and imaging information generated based on the optical information is generated. The engine control unit 102 transfers the imaging information generated by the scanner unit 120 to the image processing unit 104. The image processing unit 104 generates image information based on the imaging information received from the engine control unit 102 according to the control of the main control unit 101. Image information generated by the image processing unit 104 is stored in a storage medium attached to the image forming apparatus 1 such as the HDD 40.

  The image information generated by the image processing unit 104 is stored in the HDD 40 or the like as it is according to a user instruction or transmitted to an external device via the input / output control unit 103 and the network I / F 180. That is, the scanner unit 120 and the engine control unit 102 function as an image input unit.

  Further, when the image forming apparatus 1 operates as a copying machine, the image processing unit 104 generates drawing information based on imaging information received by the engine control unit 102 from the scanner unit 120 or image information generated by the image processing unit 104. To do. Based on the drawing information, the engine control unit 102 drives the print engine 160 as in the case of the printer operation.

  Next, details of the image processing unit 104 according to the present embodiment will be described. FIG. 3 is a block diagram illustrating functions included in the image processing unit 104 according to the present embodiment. As shown in FIG. 3, the image processing unit 104 according to the present embodiment includes a PDL analysis unit 210 and a drawing core module 220, and is integrated with a PDL application 200 configured by the CPU 10 performing calculations according to a software program. And a hardware accelerator 230 configured by a circuit.

  The PDL analysis unit 210 acquires print information described in PDL and converts it into a format that can be processed by the drawing core module 220. The converted format information is processed as a rendering command in the PDL application 200.

  The drawing core module 220 executes processing (hereinafter referred to as drawing processing) for generating drawing information for the print engine 160 to execute image formation output based on the drawing command converted by the PDL analysis unit 210. This drawing information is information of each pixel constituting an image to be imaged and output, that is, bitmap information. The drawing core module 220 also includes a function for controlling the hardware accelerator 230. The hardware accelerator 230 is hardware that executes a part of the drawing process executed by the drawing core module 220.

  FIG. 4 is a block diagram showing a functional configuration of the drawing core module 220 and the hardware accelerator 230 according to the present embodiment. 4, the drawing core module 220 includes a drawing core module I / F 221, a DL (Display List) processing unit 222, a hardware drawing processing control unit 223, an intermediate data storage unit 224, a drawing processing unit 225, and a band memory. 226.

  The drawing core module I / F 221 acquires the drawing command converted by the PDL analysis unit 210 from the PDL analysis unit 210 and inputs the drawing command to the DL processing unit 222. Based on the drawing command acquired from the drawing core module 221, the DL processing unit 222 generates a display list in which information on objects to be drawn on each page to be imaged and output is generated and stored in the intermediate data storage unit 224. To do.

  In this embodiment, the DL processing unit 222 generates a display list for each divided area called “band” obtained by dividing one page into a plurality of stages in the sub-scanning direction, and stores the display list in the intermediate data storage unit 224.

  In other words, the display list is graphic information in which drawing command information is collected for each graphic to be drawn. That is, the DL processing unit 222 functions as a graphic information generation unit. The hardware drawing process control unit 223 is a drawing process control unit that controls the hardware accelerator 230. The hardware drawing process control unit 223 holds information for controlling the hardware accelerator 230. Control of the hardware accelerator by the hardware drawing processing control unit 223 is one of the gist according to the present embodiment. As illustrated in FIG. 4, the hardware accelerator 230 includes a hardware drawing processing unit 231.

  The hardware drawing processing unit 231 executes drawing processing based on the intermediate data stored in the intermediate data storage unit 224 according to the control of the hardware drawing processing control unit 223. That is, the hardware accelerator 230 functions as a drawing information generation circuit. Note that the hardware accelerator 230 according to the present embodiment supplies power to the hardware drawing processing unit 231 only when the drawing processing is executed according to the control of the hardware drawing processing control unit 223, and supplies power during the other times. To stop. With such a function, the power consumption of the image forming apparatus 1 can be reduced.

  The intermediate data storage unit 224 is a storage area for storing the display list converted from the drawing command by the DL processing unit 222 and is a storage area secured in the RAM 20. Further, it is also used as a storage area for temporarily storing data in the middle of drawing processing by the hardware drawing processing unit 231 and the drawing processing unit 225.

  The drawing processing unit 225 is a drawing information generation unit that implements drawing processing as a software control unit configured by the CPU 10 that performs operations according to the function of the drawing core module 220, that is, a software program. The drawing processing unit 225 executes drawing processing based on the display list generated by the DL processing unit 222 and stored in the intermediate data storage unit 224.

  As described above, the display list is stored in the intermediate data storage unit 224 for each band. Accordingly, the hardware drawing processing unit 231 and the drawing processing unit 225 execute drawing processing for each band. As described above, the band memory 226 is a storage medium that stores drawing information generated by the hardware drawing processing unit 223 and the drawing processing unit 225 for each band. The band memory 226 is a storage area secured in the RAM 20.

  Next, the operation of the hardware drawing process control unit 223 according to the present embodiment will be described. FIG. 5 is a flowchart showing the operation of the drawing core module 220 according to this embodiment. As shown in FIG. 5, first, the DL processing unit 222 performs DL processing for generating and outputting a display list based on a drawing command input to the drawing core module I / F 221 (S501).

  In the processing of S501, the DL processing unit 222 extracts information (hereinafter, referred to as determination information) required by the hardware drawing process control unit 223 to be described later, and outputs the information to the hardware drawing process control unit 223. This determination information is output content information indicating the content of an image to be imaged and output. The display list output from the DL processing unit 222 is input to and stored in the intermediate data storage unit 224.

  When a display list for one page is output from the DL processing unit 222 (S502 / YES), determination information extracted from the display list for one page is also input to the hardware drawing processing control unit 223. Thus, the hardware drawing process control unit 223 acquires the determination information. The hardware drawing process control unit 223 determines whether or not the hardware accelerator is to execute the drawing process based on the determination information acquired from the DL processing unit 222 (hereinafter referred to as HA determination) (S503).

  The hardware drawing processing control unit 223 controls the hardware accelerator 230 according to the determination result of S503 and notifies the DL processing unit 222 of the determination result. The notification of the determination result includes notification of a part for causing the hardware accelerator 230 to execute the drawing process and for causing the hardware accelerator 230 to execute the drawing process.

  Here, the part for executing the drawing process means a band. Accordingly, the DL processing unit 222 does not need to cause the drawing processing unit 225 to process the band that does not require the drawing processing unit 225 to execute the drawing process, that is, the display list stored in the intermediate data storage unit 224. The display list can be recognized.

  The DL processing unit 222 causes the drawing processing unit 225 to execute drawing processing in accordance with the notification from the hardware drawing processing control unit 223. Thereby, the hardware accelerator 230 and the drawing processing unit 225 read the designated display list from the intermediate data storage unit 224 and execute the drawing process (S504).

  Next, details of the determination in S503 of FIG. 5 (hereinafter referred to as HA determination) will be described. FIG. 6 is a diagram illustrating an example of determination information extracted by the DL processing unit 222 and input to the hardware drawing processing control unit 223. “Setcolor...” Is a function for designating a color in a drawing command, and colors of RGB (Red, Green, Blue) are designated by arguments in parentheses. “Rectangle...” Is a function that designates drawing of a rectangle, and a position for drawing the rectangle is designated by an argument in parentheses.

  In the present embodiment, as shown in FIG. 6, as an example, information extracted from the display list is used as determination information. However, the display list itself is input as determination information to the hardware drawing processing control unit 223. You may do it.

  FIG. 7 is a diagram illustrating information (hereinafter referred to as HA determination condition information) held by the hardware drawing processing control unit 223 for HA determination. As shown in FIG. 7, in the HA determination condition information according to the present embodiment, a “determination item” indicating a determination target item in the content of an image formation output target image determined from the determination information, and a hardware accelerator 230 are included. “HA use” indicating a condition when the use is satisfied and “HA non-use” indicating a condition when the hardware accelerator 230 is not used are associated with “No.” which is the number of each item. Stored.

  In the example of FIG. 7, the hardware drawing processing control unit 223 performs the hardware accelerator 230 based on the determination information for one page for three items “color / monochrome”, “drawing area”, and “drawing command data size”. It is determined whether or not to execute the drawing process.

  The item “color / monochrome” is, as the name suggests, an item for determining whether an image to be image-formed and output is color or monochrome. This item can be determined by the “setcolor” command shown in FIG.

  In the case of color, generally, drawing processing is required for the above-described RGB, and processing for converting information drawn in RGB format into CMYK (Cyan, Magenta, Yellow, blackK) format is required. The amount of drawing processing is larger than that of monochrome. Therefore, the hardware drawing processing unit 225 determines the use of the hardware accelerator 230 if the image to be imaged and output is a color image.

The item “drawing area” is an item for determining the use of the hardware accelerator 230 by comparing the total area of objects drawn by a drawing command included in the display list with a predetermined threshold value S ₀ . This item can be calculated based on the drawing range indicated as an argument in the case of the “rectangle” command shown in FIG.

If the total area of the drawn object is large, more pixel information should be generated and the processing amount will increase. Therefore, hardware rendering processing control unit 223, the total area of the object to be drawn by the drawing command included in the display list, if the threshold value S ₀ or more, to determine the use of the hardware accelerator 230.

The item “drawing command data size” determines the use of the hardware accelerator 230 by comparing the data size of the drawing command itself included in the display list, that is, the amount of information of graphic information with a predetermined threshold value D _0. It is an item to be. This item can be determined by including the data size of the drawing command itself as the determination information input to the hardware drawing processing control unit 223 by the DL processing unit 222.

If the data size of the drawing command is large, the amount of processing to be executed in the drawing processing is correspondingly large. Therefore, hardware rendering processing control unit 223, the total area of the object to be drawn by the drawing command included in the display list, if the threshold value S ₀ or more, to determine the use of the hardware accelerator 230.

  In FIG. 7, the conditions “HA use” and “HA non-use” are associated with each “judgment item”, but at the minimum, it is necessary to determine whether or not the hardware accelerator 230 is to be used. It only needs to be associated with a condition. For example, in the case of “color / monochrome”, if a value of “color” is associated as a condition for using the hardware accelerator 230, the hardware drawing processing control unit 223 will determine the hardware accelerator 230 based on the determination information. It is possible to determine whether or not to use.

Here, a method of setting the threshold values S ₀ and D ₀ shown in FIG. 7 will be described. The thresholds S ₀ and D ₀ are thresholds set to realize the drawing processing time of each page so that the image forming output performance of the print engine 160 is maximized. 8A to 8C are diagrams illustrating the relationship between the image formation output performance of the print engine 160 and the time required for the drawing process.

  A numerical value indicating the image forming output performance of the print engine 160 is PPM (Page Per Minutes), that is, the number of pages that can be output per minute. When the reciprocal of the PPM is calculated, the time required for the print engine 160 to perform image formation output for one page can be calculated. In the case of the reciprocal of PPM, the unit is minutes, and by multiplying the reciprocal of PPM by 60, a numerical value in seconds can be obtained.

  8A to 8C are diagrams illustrating the relationship between the reciprocal of the PPM of the print engine 160, that is, the productivity of image formation output and the time required for drawing processing for one page. In FIGS. 8A to 8C, the time required for the drawing process is the same for each example for the sake of simplification, but in actuality, drawing is performed according to the contents of each page. The time required for processing is different.

  FIG. 8A shows a case where the productivity and the drawing processing time are balanced, that is, the drawing processing for one page is completed while the print engine 160 executes one image forming output, and the printing is performed. This is an example in which the print engine 160 can start image formation output of the next page without causing a waiting time in the engine 160.

  On the other hand, FIG. 8B is a diagram illustrating a case where the drawing processing time is long and the performance of the print engine 160 is not exhibited. In the case of FIG. 8B, the time required for the drawing process is longer than the time required for the print engine 160 to output one image. For this reason, the pace of the drawing process cannot catch up with the pace at which the print engine 160 executes the image formation output, and a waiting time occurs on the print engine 160 side. As a result, the print engine 160 cannot exhibit the maximum PPM.

  FIG. 8C is a diagram illustrating a case where the drawing processing time is shortened more than necessary. In the case of FIG. 8C, the time required for the drawing process is shorter than the time required for the print engine 160 to output one image. Therefore, although the productivity of the print engine 160 is sufficiently exhibited, the drawing information generated by the drawing process is stored in the band memory 226 until the print engine 160 completes the image formation output of the previous page. I will wait.

  In such a state, if the hardware accelerator 230 is not operated and the drawing processing is executed only by the drawing processing unit 225, the productivity of the print engine 160 is exhibited. There is no problem except that a capacity for holding is required.

  On the other hand, if the state shown in FIG. 8C has occurred even after the hardware accelerator 230 executes the drawing process, the hardware accelerator 230 is operated to speed up the drawing process more than necessary. Will be. Therefore, useless power is consumed to operate the hardware accelerator 230.

Accordingly, the threshold values S ₀ and D ₀ shown in FIG. 7 are set so as to realize the relationship between the productivity of the print engine 160 and the drawing processing time per page as shown in FIG. In other words, the threshold values S ₀ and D ₀ and the value “color” in the “color / monochrome” item described above are reference values determined according to the PPM of the print engine 160. In other words, the threshold values S ₀ and D ₀ shown in FIG. 7 are the time required for the print engine 160 to complete one image forming output, and the drawing area and the drawing so that the drawing process for one page is completed. Set for each command data size.

Then, by determining whether or not the hardware accelerator 230 needs to operate based on the threshold values S ₀ and D ₀ set in this way, the drawing processing is performed only by the drawing processing unit 225, as shown in FIG. 8B. As described above, the hardware accelerator 230 can be operated only when the time required to complete the drawing process cannot catch up with the PPM of the print engine 160. As a result, it is possible to avoid an increase in power consumption due to an unnecessarily high speed drawing process while maintaining the productivity of image formation output.

  As described above, in the drawing core module 220 according to the present embodiment, drawing processing can be performed by hardware and software in order to determine whether or not the hardware accelerator 230 needs to operate based on the content of the image to be imaged and output. In such an image forming apparatus, it is possible to reduce power consumption while maintaining productivity of image forming output.

  In the above embodiment, the DL processing unit 222 generates a display list and stores it in the intermediate data storage unit 224, and the hardware drawing processing control unit 223 makes the HA determination based on the determination information extracted at that time. The case has been described as an example where the hardware rendering processing unit 231 controlled based on the determination result acquires the display list from the intermediate data storage unit 224 and executes the rendering process.

  However, some hardware drawing processing units 231 support only a part of the processing for generating drawing information from the display list. For example, there is a mode in which the first half of the drawing processing based on the display list is executed on the drawing core module 220 side, and the latter half is shared by the hardware accelerator 230 and the drawing processing unit 225.

  In such a case, as the process before being stored in the intermediate data storage unit 224, the first half of the drawing process is executed in addition to the generation of the display list. That is, the DL processing unit 222 functions as an intermediate data processing unit that stores, as intermediate data, data obtained as a result of executing not only the display list processing but also the first half of the drawing processing as intermediate data.

  FIG. 9 is a diagram showing an example of the flow of the drawing process and the boundary between the first half and the second half of the process according to the present embodiment. The flow of the drawing process shown in FIG. 9 is the flow of the drawing process of the band including the image object. As shown in FIG. 9, the rendering processing according to the present embodiment includes “input”, “format conversion”, “color matching”, “BG (Back Ground) / UCR (Under Color Removal)”, “γ conversion”, It includes processes such as “value reduction (dithering)” and “drawing to band memory”.

  In FIG. 9, the process up to the color matching process is performed as the first half part before being stored in the intermediate data storage unit 224, and the subsequent processes are performed by the hardware accelerator 230 or the drawing processing unit 225. Even in such a case, the hardware rendering process control unit 223 can determine whether or not to operate the hardware accelerator 230 in the same manner as described above, thereby obtaining the effects described above. Become.

  Further, after the DL processing unit 222 generates a display list and stores it once in the intermediate data storage unit 224, the drawing processing unit 225 executes the first half of the drawing process, and the processing result data is again transmitted to the intermediate data storage unit. It is also possible to store in the H.224 and share the subsequent processing between the hardware accelerator 230 and the drawing processing unit 225. Even in such a case, the same effects as described above can be obtained by applying the present embodiment.

  Further, in the above embodiment, the description has been made on the assumption that the color is “full color” in the determination of “color / monochrome” of the “determination item” shown in FIG. However, the color of the image formation output is not limited to the full color, and there are cases where there are two colors, and the larger the number of colors, the larger the processing amount. Therefore, the determination item may be “number of colors” instead of “color / monochrome”, and a threshold value may be provided for the number of colors. This makes it possible to make a determination corresponding to more various conditions.

  According to such a viewpoint, since the determination item “color / monochrome” in FIG. 7 does not consider the number of colors, the threshold of “two colors” is set for the number of colors. .

Embodiment 2. FIG.
In the present embodiment, the contents of HA determination according to an aspect different from the aspect described in FIG. 7 will be described. FIG. 10 is a diagram showing HA determination condition information held by the hardware drawing process control unit 223 according to the present embodiment. As shown in FIG. 10, in the HA determination condition information according to the present embodiment, the drawing commands included in the display list and the “data size coefficient” and “drawing area coefficient” set for each command are as follows: It is stored in association with “No.” which is the number of each command.

  For example, in the case of the image drawing command shown as “Image” in FIG. 10, both the color processing and the storage of data in the band memory 226 have a high processing load, but the color processing of the character drawing command shown by “Text” Since the number of colors used is small and the processing amount of “color matching”, “BG / UCR”, and “γ conversion” shown in FIG. 9 is small, the processing load is low.

Therefore, the hardware drawing processing control unit 223 according to the present embodiment, as shown in FIG. 10, “data size coefficient” and “weighting values” set for each drawing command for the drawing command data size and the drawing area, respectively. Using the “drawing area coefficient”, the processing load R for processing the drawing command is calculated by the following equation (1).

Here, “D” in Expression (1) is the drawing command data size, and “S” is the drawing area. The drawing command data size D and the drawing area S can be acquired by the same method as in the first embodiment. “T ₁ ” and “T ₂ ” are a “data size coefficient” and a “drawing area coefficient” acquired from FIG. The sigma in equation (1) indicates that the values are summed for one page of drawing commands.

  Furthermore, the hardware drawing process control unit 223 according to the present embodiment holds a table as shown in FIG. 11 as HA determination condition information. The table shown in FIG. 11 is a table showing the drawing processing performance when the drawing processing is executed without operating the drawing core module 220, that is, the hardware accelerator 230. The table shown in FIG. It is a table in which the corresponding “processing load R” and the “processing time t” required for drawing processing in each processing load R are associated.

  The table as shown in FIG. 11 can be generated by, for example, executing drawing processing under various conditions before measuring the image forming apparatus 1 and measuring and storing the time required for the execution. Further, values measured under the same conditions may be input from the outside and stored in the hardware drawing processing control unit 223. When the processing load R is calculated by the above equation (1), the hardware drawing processing control unit 223 according to the present embodiment obtains a processing time t corresponding to the calculated processing load R with reference to the table shown in FIG.

  If a value that matches the calculated processing load R is not stored in the table, the hardware drawing process control unit 223 uses the value of t associated with each of the two R values stored in the table. Then, the value of t corresponding to the calculated R is obtained by an approximate curve or linear approximation. By comparing t obtained in this way with the productivity of the print engine 160, it is possible to determine whether or not the hardware accelerator 230 is to be used.

  With reference to FIG. 12, the HA determination operation by the hardware drawing processing control unit 223 according to the present embodiment will be described. In the present embodiment, the operation of FIG. 12 is the process of the hardware drawing process control unit 223 in S503 of FIG. As shown in FIG. 12, when starting the HA determination operation, the hardware drawing processing control unit 223 calculates R by the above equation (1) (S1201).

  The hardware drawing process control unit 223 repeats the calculation process of R for the drawing commands for one page and sums the calculation results (S1202 / NO). When the calculation of R for one page is completed (S1202 / YES), Based on the calculated value of R, t is acquired from the table shown in FIG. 11 (S1203).

  Then, the hardware drawing processing control unit 223 compares the acquired t with the inverse of the PPM of the print engine 160 (S1204). That is, the reciprocal number of PPM is used as a threshold value. Since the unit of the reciprocal number of PPM is (minutes), if the unit of the value of t is (seconds), the hardware drawing processing control unit 223 increases the reciprocal number of PPM by 60 and matches the units. Compare with. As a result of the comparison in S1204, if t is smaller than the reciprocal of PPM (S1204 / YES), the hardware drawing process control unit 223 determines that the operation of the hardware accelerator 230 is unnecessary (S1205), and ends the process. To do.

  On the other hand, if t is equal to or greater than the reciprocal of PPM as a result of the comparison in S1204 (S1204 / NO), the hardware drawing process control unit 223 determines that the operation of the hardware accelerator 230 is necessary (S1206), and the process Exit. With such processing, the HA operation according to the present embodiment is completed.

  As described above, in this embodiment, the reciprocal number of the PPM, that is, the time required for the print engine 160 to execute the image formation output for one page is used as the reference value determined according to the PPM of the print engine 160. Use. This makes it possible to determine the drawing processing time that must be satisfied in order to exhibit PPM.

  As described above, in the drawing core module 220 according to the present embodiment, the processing load for each drawing command is calculated based on the weight value set for each drawing command, and the processing time determined according to the calculation result. Is compared with the productivity of the print engine 160 to determine whether the operation of the hardware accelerator 230 is necessary. Thereby, it is possible to determine whether or not the operation of the hardware accelerator 230 is necessary with higher accuracy.

  In the present embodiment, when the table shown in FIG. 11 is used, the processing load R obtained by the above equation (1) is converted into the processing time t and then compared with the reciprocal of the print engine 160. As an example. However, the hardware drawing processing control unit 223 holds the value obtained by converting the reciprocal of the print engine 160 into the processing load as a threshold value, so that the same effect as described above can be obtained. Further, in this case, it is only necessary to store the threshold value instead of the table as shown in FIG. 11, so that the amount of information to be stored can be reduced.

Embodiment 3 FIG.
In the present embodiment, a case where a plurality of hardware drawing processing units 231 are provided will be described. FIG. 13 is a block diagram showing a functional configuration of the drawing core module 220 and the hardware accelerator 230 according to the present embodiment. As illustrated in FIG. 13, the hardware accelerator 230 according to the present embodiment includes two hardware drawing processing units as a hardware drawing processing unit 231a and a hardware drawing processing unit 231b. These two hardware drawing processing units can execute different drawing processes in parallel, thereby improving the efficiency of the drawing process per unit time.

  Each of the hardware drawing processing unit 231a and the hardware drawing processing unit 231b has the same function as the hardware drawing processing unit 231 described in the first embodiment. That is, the hardware drawing processing unit 231a and the hardware drawing processing unit 231b execute drawing processing based on the display list stored in the intermediate data storage unit 224, respectively, under the control of the hardware drawing processing control unit 223. Drawing information is stored in the band memory 226.

  Also in the present embodiment, the hardware drawing processing control unit 223 controls the hardware accelerator 230 so that the PPM of the print engine 160 is exhibited. The function of the hardware drawing process control unit 223 according to the present embodiment will be described below in each case of the control according to the aspect of the first embodiment and the control according to the aspect of the second embodiment.

  FIG. 14 is a diagram illustrating an example of HA determination condition information held by the hardware drawing process control unit 223 when control according to the aspect of the first embodiment is performed, and has been described with reference to FIG. 7 of the first embodiment. It corresponds to information.

  As shown in FIG. 14, in the HA determination condition information according to the present embodiment, “HA” indicating a condition when two hardware drawing processing units 231 are used for the “determination item” described in FIG. “Use 2”, “HA use 1” indicating a condition when one hardware drawing processing unit 231 is used, and “HA non-use” indicating a condition when the hardware accelerator 230 is not used, respectively. It is stored in association with the item number “No.”.

  The hardware drawing processing control unit 223 according to the present embodiment is input from the DL processing unit 222 by performing the determination by the same processing as in the first embodiment using the HA determination condition information as illustrated in FIG. Based on the determination information, it is possible to determine how many two hardware drawing processing units included in the hardware accelerator 230 are to be operated.

FIG. 15 is a diagram illustrating an example of HA determination condition information held by the hardware drawing process control unit 223 when control according to the aspect of the second embodiment is performed, and has been described with reference to FIG. 11 of the second embodiment. It corresponds to information. In the table shown in FIG. 15, in addition to “CPU only processing time t ₁ ” corresponding to “processing time t” in FIG. 11, only _one hardware drawing processing unit is operated to execute drawing processing. “CPU + HA processing time t ₂ ” indicating the time required for the drawing processing is associated with each processing load R.

The hardware drawing process control unit 223 according to the present embodiment uses such a table to calculate the processing times t ₁ and t ₂ corresponding to the processing load R calculated by the equation (1) described in the second embodiment. Each value is compared with the reciprocal of the PPM of the print engine 160. Thus, in addition to whether or not to operate the hardware accelerator 230, when operating the hardware accelerator 230, it is possible to determine how many hardware rendering processing units are to be operated.

FIG. 16 is a flowchart showing an HA determination operation when the hardware drawing processing control unit 223 according to the present embodiment performs control according to the aspect of the second embodiment. As illustrated in FIG. 16, the hardware drawing process control unit 223 performs the same processes as in S <b> 1601 and S <b> 1602 up to S <b> 1202 in FIG. 12. Upon completion of the calculation of R for one page (S1602 / YES), the hardware rendering processing control unit 223 acquires the _t 1, _{t 2} from the table shown in FIG. 15 on the basis of the calculated value of the R (S1603) .

When the values of t ₁ and t ₂ are acquired, the hardware drawing process control unit 223 first compares the value of t ₁ with the inverse of the print engine 160 (S1604). Results of the comparison of S1604, if _{t 1} is less than the reciprocal of the PPM (S1604 / YES), the hardware rendering processing control unit 223, the operation of the hardware accelerator 230 determines that it is not necessary (S1605), processes the finish.

On the other hand, if the comparison result of S1604, _{t 1} or more inverse of PPM (S1604 / NO), then the hardware rendering processing control unit 223 compares the inverse number of the value and the print engine 160 _{t 2} (S1606). Results of the comparison of S1604, if _{t 2} is less than the reciprocal of the PPM (S1606 / YES), the hardware rendering processing control unit 223 determines to use only one hardware rendering processing unit (S1607), The process ends.

Results of the comparison of S1606, if _{t 2} is more than the reciprocal of the PPM (S1606 / NO), the hardware rendering processing control unit 223, the operation of both the two hardware rendering processing unit included in the hardware accelerator 230 It is determined that it is necessary (S1608), and the process is terminated. With such processing, the HA operation according to the present embodiment is completed.

  In this embodiment, the case where the hardware accelerator 230 includes two hardware drawing processing units 231a and 231b has been described as an example. However, there are three or more hardware drawing processing units. However, it can be similarly applied. In that case, in the case of the aspect of FIG. 14, if the conditions for the number of hardware rendering processing units are set corresponding to each “judgment item”, the hardware rendering processing control unit 223 performs the DL processing. Based on the determination information input from the unit 222, the number of hardware drawing processing units to be used can be determined.

Further, in the case of FIG. 15, the number of hardware drawing processing units to be operated is increased by one following “CPU only processing time t ₁ ” and “CPU + HA processing time t ₂ ” shown in FIG. The data is stored in association with the processing load R until the number of hardware drawing processing units that is one less than the number of hardware drawing processing units included in the hardware accelerator 230 is operated. Then, by increasing the determinations in S1604 and S1606 in FIG. 16, even if there are three or more hardware rendering processing units included in the hardware accelerator 230, the same applies as in the modes in FIGS. It is possible.

  As described above, according to the configuration of the image processing unit 104 according to the present embodiment, the productivity of image formation output is maintained even when the hardware accelerator 230 includes a plurality of hardware drawing processing units. In addition, power consumption can be reduced.

1 Image forming apparatus 10 CPU
20 RAM
30 ROM
40 engine 50 HDD
60 I / F
70 LCD
80 Operation Unit 90 Bus 100 Controller 101 Main Control Unit 102 Engine Control Unit 103 Input / Output Control Unit 104 Image Processing Unit 105 Operation Display Control Unit 110 ADF
120 Scanner unit 130 Paper discharge tray 140 Display panel 150 Paper feed table 160 Print engine 170 Paper discharge tray 180 Network I / F
200 PDL Application 210 PDL Analysis Unit 220 Drawing Core Module 221 Drawing Core Module I / F
222 DL processing unit 223 Hardware drawing processing control unit 224 Intermediate data storage unit 225 Drawing processing unit 226 Band memory 230 Hardware accelerator 231, 231a, 231b Hardware drawing processing unit

JP 2008-186299 A

Claims (9)

An image forming apparatus capable of executing image processing for executing image forming output by hardware and software,
Based on a drawing command obtained based on the page description language, a graphic information generating unit that generates graphic information in which information is collected for each graphic to be drawn;
A drawing information generating unit for executing drawing processing for generating drawing information for the image forming unit to execute image forming output based on the generated graphic information by software processing;
A drawing information generation circuit for executing the drawing processing as hardware;
A drawing processing control unit that controls execution of a pre-drawing process by the drawing information generation circuit,
The drawing process control unit
In response to the generation of the graphic information, output content information indicating the content of the image to be imaged and output is obtained,
A reference value determined according to the number of images that can be imaged and output per unit time by an image forming unit that executes image forming output, and a processing amount of the drawing process that is determined based on the acquired output content information An image forming apparatus characterized in that, based on the drawing information generation circuit, it is determined whether the drawing process needs to be executed.   The drawing processing control unit, when the area of the figure to be drawn obtained based on the output content information exceeds a threshold predetermined as the reference value, the drawing processing by the drawing information generation circuit The image forming apparatus according to claim 1, wherein the image forming apparatus determines that the image is necessary.   The drawing processing control unit acquires an information amount of the graphic information as the output content information, and when the acquired information amount exceeds a predetermined threshold as the reference value, the drawing information generation circuit The image forming apparatus according to claim 1, wherein the image forming apparatus determines that the drawing process is necessary.   The drawing process control unit calculates a value related to the processing load of the drawing process using a weight value determined for each type of figure to be drawn based on the acquired output content information, and the calculation result and the reference value 4. The image forming apparatus according to claim 1, wherein whether or not the drawing processing by the drawing information generation circuit is necessary is determined based on a comparison result with a predetermined threshold.   The drawing processing control unit draws using a weight value determined for each type of figure to be drawn for each of the area of the figure to be drawn and the information amount of the figure information obtained based on the output content information The image forming apparatus according to claim 4, wherein a value related to a processing load of processing is calculated.   The drawing processing control unit determines the number of colors used in the image formation output based on the output content information, and when the number of colors exceeds a predetermined number as the reference value, the drawing information generation circuit performs the 6. The image forming apparatus according to claim 1, wherein it is determined that drawing processing is necessary. The drawing information generation circuit includes a plurality of drawing processing means operable in parallel,
The drawing processing control unit, based on a plurality of the reference values determined according to the number of drawing processing means to be operated, and the processing amount of the drawing processing determined based on the acquired output content information, The image forming apparatus according to claim 1, wherein the number of the drawing processing units operated in the drawing information generation circuit is determined. Generation of drawing information for executing image forming output in an image forming apparatus including a drawing information generating circuit for executing image processing for executing image forming output as hardware and a drawing information generating unit for executing by software processing A drawing processing control program for controlling,
Generating graphic information in which information is collected for each graphic to be drawn based on a drawing command obtained based on a page description language;
In response to the generation of the graphic information, obtaining output content information indicating the content of the image to be imaged and output;
A reference value determined according to the number of images that can be imaged and output per unit time by an image forming unit that executes image forming output, and a processing amount of the drawing process that is determined based on the acquired output content information And a step of causing the image forming apparatus to execute a step of determining whether or not to execute the drawing process by the drawing information generation circuit. Generation of drawing information for executing image forming output in an image forming apparatus including a drawing information generating circuit for executing image processing for executing image forming output as hardware and a drawing information generating unit for executing by software processing A drawing processing control method for controlling,
Based on the drawing command obtained based on the page description language, generate graphic information that summarizes information for each graphic to be drawn,
In response to the generation of the graphic information, output content information indicating the content of the image to be imaged and output is obtained,
A reference value determined according to the number of images that can be imaged and output per unit time by an image forming unit that executes image forming output, and a processing amount of the drawing process that is determined based on the acquired output content information Based on the drawing information generation circuit, it is determined whether or not the drawing process needs to be executed.

Images