JP2008073955A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which can achieve high speed print processing while taking account of the memory area of an RAM. <P>SOLUTION: Before starting print processing for a print request, a print processing program 16A and print processing data recorded in a serial ROM 16 are copied to an SDRAM 17. A decision is then made whether font data 16B or demonstration print data 16C is required or not in the print processing performed in response to a print request. If it is not required, a font data area 17B or a demonstration print data area 17C assured for the unnecessary data is released for development processing of print data. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly, to memory control during print processing.

Japanese Patent Application Laid-Open Publication No. 2004-228561 discloses a technique related to a printer controller including a serial ROM, a CPU, and a RAM that store a program used when the printer is started up and a program used for printer printing. Specifically, the CPU reads out the program used for the printer printing process from the serial ROM in accordance with the program used when starting up the printer, copies the program to the RAM, and performs the printing process according to the copied program. If the program is directly fetched from a low-speed serial ROM and the CPU is moved, the problem arises that the print processing speed slows down. However, in the above technique, the program is copied to a high-speed RAM, and the print processing is performed according to the copied program. As a result, the print processing speed is prevented from being slowed down.
Japanese Patent Application Laid-Open No. 2004-240693

  However, in the technique of the above-mentioned Patent Document 1, every time a read request is made, only a part of program data (specifically, data for one page) corresponding to the read request is read from the serial ROM. Therefore, when there is a read request for program data of a page different from the previous one, it is necessary to read the page program data from the serial ROM, and there is a problem that the processing speed is reduced accordingly. In addition, since the RAM to which the program data is copied requires a large storage area to be secured when the print data is expanded, it is necessary to consider the storage area of the RAM.

  The present invention has been completed based on the above situation, and an object of the present invention is to provide an image forming apparatus capable of speeding up printing processing in consideration of a storage area of a RAM. is there.

As means for achieving the above object, an image forming apparatus according to the invention of claim 1 is provided for starting up the image forming apparatus, a serial ROM in which a print processing program and print processing data are recorded, a RAM, and the like. A copy unit for reading the print processing program and the print processing data recorded in the serial ROM and copying them to the RAM; and the print processing program and the print processing data copied to the RAM. Of the print processing program and the print processing data copied to the RAM when there is a print request and a print unit that executes the print processing based on the print request, the print processing that is not required by the print processing executed by the print request An unnecessary part determination unit that determines whether or not there is a part, and the unnecessary part determination unit when the unnecessary part determination unit determines that there is an unnecessary part. Comprising a deletion unit for deleting the minutes from the RAM, and.
The “image forming apparatus” of the present invention is not limited to a printing apparatus such as a printer (for example, a laser printer), but may be a facsimile machine or a multifunction machine having a printer function and an image reading function (scanner function). Good.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, an unnecessary portion deleted by the deletion unit is read from the serial ROM after a print process executed by the print request is completed. A re-copy unit for re-copying to the RAM is provided.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the unnecessary portion determination unit includes a special function program or data included in the print processing program and the print processing data. Judgment is made based on whether or not the printing process executed by the print request is unnecessary.

  According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the unnecessary portion determining unit includes the font data included in the print processing program and the print processing data. Judgment is made based on whether or not the printing process is executed according to the print request.

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, when there is a print request, the free space of the RAM is reduced by a print process executed by the print request. A free capacity determination unit that determines whether or not there is a possibility of a shortage, and the unnecessary part determination unit determines whether or not the unnecessary part is present when the free capacity determination unit determines that the free capacity is insufficient; Make a decision.

  According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects, the copy unit preferentially copies the print processing program to the RAM.

<Invention of Claim 1>
Based on the activation of the image forming apparatus, all the print processing program and print processing data recorded in the serial ROM are temporarily copied to the RAM. When there is a print request, if there is an unnecessary program or / and data in the print processing executed by the print request, the unnecessary part is deleted from the RAM (including overwriting other data). Thus, it is possible to secure a storage area of the RAM during the printing process.

<Invention of Claim 2>
Since the unnecessary portion (program or data) is re-replicated to the RAM after the print processing by one print request is completed, even when the unnecessary portion is used in the print processing by the next print request, the high-speed print processing can be performed. It becomes possible.

<Invention of Claim 3>
Special function data (for example, demo print data, test data for image density adjustment and transfer position adjustment) is an unnecessary part unless a special function is designated. Therefore, when the print request is not for executing such a special function, the special function program or / and data is set as a deletion target.

<Invention of Claim 4>
For example, when the print data to be printed is image data (for example, copy data, scanner data, facsimile data, etc.), font data is usually unnecessary. Therefore, it is possible to determine whether or not the font data is to be deleted according to the type of the function executed (copy function, scanner function, facsimile function, data printing function) and the data type of the print data.

<Invention of Claim 5>
It is desirable that the unnecessary portion be deleted and the unnecessary portion be deleted only when there is a possibility that the RAM has insufficient free space.

<Invention of Claim 6>
If the print processing program is preferentially copied to the RAM, the print processing based on the print processing program can be started earlier than the configuration in which the print processing data is preferentially copied to the RAM.

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS.
1. Configuration of Printer FIG. 1 is a block diagram illustrating a configuration of a printer 10 according to the present embodiment (for example, an example of a laser printer “image forming apparatus”). As shown in the figure, the printer 10 includes a print control unit 12 that controls the overall operation of the printer 10. The print control unit 12 includes a CPU 11, a reset controller 13, a low speed memory controller 14, and a high speed memory controller 15.

  Among these, the high-speed memory controller 15 is connected to a RAM (SDRAM (Synchronous Dynamic Randam-Access Memory) 17 in this embodiment). Specifically, for example, when the data length handled by the CPU 11 is 32 bits, the high-speed memory controller 15 and the SDRAM 17 are connected via 15 address buses, 8 control lines, and 32 signal lines as data buses. These signal lines are connected, and exchange of data is performed at high speed by parallel transmission.

  A serial ROM (Read Only Memory) 16 is connected to the low-speed memory controller 14. In general, the serial ROM 16 exchanges data through four signal lines of CS (chip select), SCK (clock), SI (serial input), and SO (serial output). That is, when CS is activated and bit data is serially input in the order of operation code and address to SI at the rising edge of SCK, the read data is output from SO. Thus, if the serial ROM 16 is used, the signal lines for ROM access can be reduced, and the substrate can be downsized. However, the serial ROM 16 has a demerit that the reading speed is low because data is exchanged by serial transmission.

  Therefore, in the present embodiment, as will be described later, the print processing program 16A and the print processing data (including font data 16B and demo print data 16C in the present embodiment) recorded in the serial ROM 16 are read out to the SDRAM 17. The CPU 11 performs the printing process according to the printing processing program 16A and the like copied and copied to the SDRAM 17 capable of high-speed reading and writing.

  The CPU 11 includes a low-speed memory controller 14, a high-speed memory controller 15, a USB interface controller 18, a parallel port interface controller 19, a print engine controller 20 that controls the print engine 20A, and an operation panel controller 21 that controls the operation panel 21A via a bus. Connected. The printer 10 receives print data from an external personal computer 30 via the USB interface controller 18 or the parallel port interface controller 19, and the received print data is transferred to the high-speed memory controller 15 by DMA (Direct Memory Access). Transferred. The received print data is subjected to data expansion processing based on the control executed by the CPU 11 in accordance with the print processing program 16A copied to the SDRAM 17, and the expansion data is transferred from the SDRAM 17 to the print engine 20A. As a result, the print engine 20A forms an image based on the transferred development data and transfers the image onto a sheet as a print medium.

  The reset controller 13 gives reset signals to the CPU 11, the low-speed memory controller 14, the high-speed memory controller 15, the USB interface controller 18, the parallel port interface controller 19, the print engine controller 20, and the operation panel controller 21, respectively, to reset the CPU 11. It is possible to make it. Further, the CPU 11 executes various controls based on operation signals corresponding to each operation on the operation panel 21A.

2. Memory map (1) Serial ROM
FIG. 2 shows a memory map of the serial ROM 16 and the SDRAM 17. The serial ROM 16 stores a print processing program 16A, font data 16B, and demo print data 16C. Among these, the print processing program 16 </ b> A is a program for causing the CPU 11 to execute print data expansion processing, print engine A control processing, and the like.

  The font data 16B is a font of characters used in the print data expansion process and its data. The print data from the personal computer 30 is an image (eg, bitmap) such as PDL (Page Description Language) data. Is used for the expansion process. On the other hand, the font data 16B is not used when the print data is received as image data such as GDI (Graphics Device Interface) data.

  The demo print data 16C (an example of “special function data”) is data used when the demo print function is designated on the personal computer 30 or the operation panel A21, for example. Therefore, the data is not used during normal print processing for print data from the personal computer 30.

(2) SDRAM
As shown in FIG. 2, the SDRAM 17 has a print processing program area 17A, a font data area 17B, a demo print data area 17C, and a work area 17D. In the work area 17D, a print data development area 17E, an interface input data buffer 17F, a print data output band buffer 17G, and a system word area 17H are further secured. The print data expansion area 17E is a storage area that is used during a print data expansion process, which will be described later. In particular, a large storage area is required during the expansion process for language data such as the PDL data. The interface input data buffer 17F is a storage area used for temporarily storing print data transferred from the USB interface controller 18 or the parallel port interface controller 19. The print data output band buffer 17G is a storage area that is used to temporarily store the expanded data that has been expanded, and the system word area 17H is a storage area that is used for the operation of the CPU 11. is there.

3. Operation of Print Control Unit The operation content of the print control unit 12 will be described with reference to the flowcharts shown in FIGS. As described above, the print control unit 12 includes the CPU 11, the reset controller 13, the low-speed memory controller 14, and the high-speed memory controller 15, and these may operate in parallel. The operations of the print control unit 12 will be described together.

(1) When the printer is turned on When the printer 10 is turned on, the print control unit 12 executes the control shown in FIG. First, in S1, the reset controller 13 outputs, for example, a high level reset signal (described as “reset, cpu_reset” in FIG. 1), and the CPU 11, the low-speed memory controller 14, the high-speed memory controller 15, the USB interface controller 18, and the like. All the parallel port interface controllers 19 are reset. Next, in S <b> 2, the reset controller 13 releases the reset state of the other controllers 14, 15, 18, 19 while only the CPU 11 holds the reset state. Thereby, operations other than the CPU 11 can be performed.

  Next, in S3, the low speed memory controller 14 reads out the print processing program 16A recorded in the SDRAM 17 and transfers it to the high speed memory controller 15 by DMA. The high speed memory controller 15 transfers the print processing program 16A to the SDRAM 17 print processing. The program area 17A is copied. When the transfer of the print processing program 16A is completed (S4: Y), the low speed memory controller 14 notifies the reset controller 13 that the transfer of the print processing program 16A is completed (S5). At this time, in the present embodiment, regardless of whether or not the program is necessary for the printing process corresponding to the subsequent printing request, all the printing process program 16A recorded in the serial ROM 16 is temporarily copied to the SDRAM 17, Wait for print request. At this time, the print control unit 12 functions as a “copying unit”.

  The reset controller 13 notified of the end of transfer of the print processing program 16A cancels the reset state of the CPU 11 in S6. In short, the reset controller 13 prevents the CPU 11 from operating unless all the print processing programs 16A are copied to the SDRAM 17. In step S7, the CPU 11 starts an operation according to the print processing program 16A copied to the SDRAM 17 and starts controlling the print engine 20A. Here, for example, the heater temperature rise of the fixing device and the sensor check (the presence / absence of the toner cartridge, the remaining amount of toner / paper jam check / the cover open check of the main body case / the motor operation check, etc.) are executed (see FIG. S8). When the warm-up process is completed (S9: Y), the process proceeds to S12 in FIG.

  In parallel with the processing of S8 and S9, the low-speed memory controller 14 reads the font data 16B and the demo print data 16C recorded in the SDRAM 17, and transfers them to the high-speed memory controller 15 by DMA. The font data 16B is copied to the font data area 17B of the SDRAM 17 and the demo print data 16C is copied to the demo print data area 17C of the SDRAM 17 (S10). At this time, the print control unit 12 functions as a “copying unit”.

  When the transfer of the print processing data is completed (S11: Y), the process proceeds to 13 in FIG. As a result, the print processing program 16A and the print processing data recorded in the serial ROM 16 are all copied to the SDRAM 17, and the print control unit 12 can execute the print processing, and wait for the print request. (S20 in FIG. 4). The print request includes not only a print request from the personal computer 30, but also an execution request on the operation panel 21A for a so-called direct print function for printing a file in an external memory directly connected to the printer 10. included. When the printer 10 is a multifunction machine having a fax function, a scanning function, a copy function, and the like, an execution request on the operation panel 21A for each function is also included.

  For example, when a print request is made from the personal computer 30 (S21: Y), the CPU 11 confirms whether or not the copy processing of the print processing program 16A and the print processing data from the serial ROM 16 to the SDRAM 17 is completed in S21. If completed (S21: Y), the USB interface controller 18 or parallel port interface controller 19 that received the print data in S22 transfers the print data to the high-speed memory controller 15 by DMA, and this high-speed memory controller 15 Temporarily stores the print data in the interface input data buffer 17F of the SDRAM 17.

(2) Determination of presence / absence of free area Then, in S23, the CPU 11 reads the print data stored in the interface input data buffer 17F at any time via the high-speed memory controller 15, executes the expansion processing to the bitmap, Processing for transferring data to the print data output band buffer 17G via the high-speed memory controller 15 is started. At this time, the print control unit 12 functions as a “printing unit”. Here, the print data expansion process is basically performed using the print data expansion area 17E. However, as described above, when the print data is, for example, PDL data, it is particularly suitable for the expansion process. If a large storage area is not secured, the expansion process takes time, and the printing process as a whole becomes slow.

  Therefore, in S24, the CPU 11 determines whether or not there is a free area (free capacity) of a predetermined range or more in the print data development area 17E via the high speed memory controller 15. At this time, the print control unit 12 functions as a “free capacity determination unit”. If it is determined that there is some free space (S24: N), the print data expansion process is continued without expanding the current print data expansion area 17E. When the process of transferring the developed data to the print data output band buffer 17G is completed in S25, the process of transferring the developed data stored in the print data output band buffer 17G to the print engine 20A as needed is started. Thus, printing on a sheet is executed. In S27, the CPU 11 confirms whether or not a data reacquisition flag to be described later is set. If it is set (S27: Y), the process returns to S10 in FIG. On the other hand, if not standing (S27: N), the process returns to the print request waiting state in S20.

(3) When there is no empty area When it is determined that there is almost no empty area in the print data development area 17E (S24: Y), it is determined whether or not the demo print data 16C is stored in the demo print data area 17C in S28. If it is present (S28: Y), it is determined whether or not the demo print data 16C is necessary in the print data expansion process received this time (S29). This determination can be made based on whether the demonstration print function is designated on the personal computer 30 or the operation panel 21A and the execution command is received by the CPU 11. When the CPU 11 has not received the execution command for the demo print function (S29: N), the demo print data 16C is unnecessary data in this development process, so the demo print data area 17C is released as a work area in S30. To do. That is, the print data development area 17E is expanded to the demo print data area 17C. At this time, the print control unit 12 functions as a “deletion unit, unnecessary portion determination unit”. As a result, the development data is overwritten on the demo print data 16C stored in the demo print data area 17C. Therefore, in S31, a data reacquisition flag is set to instruct to reacquire data from the serial ROM 16.

  For example, when the print data expansion area 17E has already been expanded to the demo print data area 17C in S30 and the demo print data 16C is no longer in the SDRAM 17 (S28: N), the demo print data 16C is in the SDRAM 17 but the demo print function is designated. If yes (S28: Y and S29: Y), the process proceeds to S32. Here, it is determined whether or not the font data 16B is necessary in the current development process. For example, when the print data from the personal computer 30 is GDI data, the font data 16B is not necessary for the expansion process. Further, when the printer 10 is a multifunction machine and any one of the facsimile function, scanning function, and copy function can be designated, each facsimile data, scanning data, and copy data already constitute image data, Again, the font data 16B is unnecessary.

  Accordingly, when the received print data is GDI data, or when the CPU 11 receives an execution command of any one of the facsimile function, scanning function, and copy function (S32: N), the font data area 17B is stored in S33. Open as a work area. That is, the print data development area 17E is expanded to the font data area 17B. At this time, the print control unit 12 functions as a “deletion unit, unnecessary portion determination unit”. As a result, the expanded data is overwritten on the font data 16B stored in the font data area 17B. Therefore, in S31, a data reacquisition flag is set to instruct to reacquire data from the serial ROM 16. When the font data 16B is used in the current printing process (S32: Y), the process waits until an empty area is finally created in the print data development area 17E (S34: Y). S34: N), the process proceeds to S23.

(4) Data Reacquisition Process After setting the data reacquisition flag in S31, the process of S23 is further advanced. Then, returning to step S30, when the print data development area 17E is expanded in S30 and S33, a sufficient free area is secured in the print data development area 17E (S24: N), the printing process corresponding to the current print request (N). After the end of S25, S26), since the data reacquisition flag is set (S27: Y), the process returns to S10 in FIG. That is, a data reacquisition process is executed in which the font data 16B and the demo print data 16C that are no longer necessary in S29 and S32 are read from the serial ROM 16 and copied to the SDRAM 17 again. At this time, the print control unit 12 functions as a “re-copying unit”.

4). Advantages of the present embodiment (1) According to the present embodiment, the print processing program 16A and print processing data once recorded in the serial ROM 16 are copied to the SDRAM 17 before execution of the print processing for the print request. When there is a print request, it is determined whether or not the font data 16B and the demo print data 16C are unnecessary in the print processing executed by the print request. The font data area 17B and the demo print data area 17C are opened for print data expansion processing. Thereby, a wide work area 17D in the SDRAM 17 can be secured during the print data expansion process.

  (2) Also, the font data 16B and the demo print data 16C determined to be unnecessary in the printing process according to one printing request are read from the serial ROM 16 immediately after the printing process is finished, and re-copied to the SDRAM 17 in this state. Wait for the next print request. Therefore, for example, even if the print process for the next print request is a process that uses the font data 16B or a process that uses the demo print data 16C (for example, when the demo print function is executed), the print process is accelerated. Can start.

  (3) Further, by performing the expansion (S30, S33) of the print data expansion area 17E only when the print data expansion area 17E becomes insufficient, the data re-income process is performed wastefully. Can be avoided.

  (4) When the print processing program 16A is copied to the SDRAM 17, the CPU 11 is released from the reset state (S6), enabling the print engine 20A to be controlled before the print processing data copy processing is completed, By starting the warm-up process as an advance preparation at an early stage, it is possible to start the print process quickly when a print request is made.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above-described embodiment, the font data 16B is given as an example of an unnecessary part in the printing process. However, other than this, for example, test data for image density adjustment and transfer position adjustment, etc. It may be data for special functions that are used only for special functions and are not used in normal printing processing. Further, for example, when an image density adjustment program, a transfer position adjustment program, a demonstration print processing program, and the like are included in the print processing program 16A in module units, print data as unnecessary portions in those module units. A configuration for opening to the development area 17E is also possible. Further, even when a program for a facsimile function, a scanning function, or a copy function is included in the print processing program 16A in units of modules, there is also a configuration in which they are subject to release to the print data development area 17E as unnecessary portions in units of modules. Is possible.

  (2) In the above embodiment, when the print data development area 17E has a vacant area, the unnecessary portion determination process (S28, S29, S32, etc.) is executed. Regardless of whether or not there is an empty area of 17E, whether it is so-called PC printing, execution of the factory function, scanning function for the data type (for example, whether the print data is PDL data or GDI data) and the print data from the personal computer 30, the scanning function It may be determined whether or not to execute the copy function or the copy function based on an operation on the operation panel 21A or the like, and for example, an unnecessary part determination process is executed only during PC printing.

1 is a block diagram showing a configuration of a printer according to an embodiment of the present invention. Memory map of serial ROM and SDRAM Flow chart showing operation contents of print control unit (No. 1) Flow chart showing operation contents of print control unit (part 2)

Explanation of symbols

10. Printer (image forming apparatus)
12 ... Print control unit (copying unit, printing unit, unnecessary part judging unit, deleting unit, re-copying unit, free space judging unit)
16 ... Serial ROM
16A: Print processing program 16B: Font data (print processing data)
16C ... Demo print data (special function data)
17 ... SDRAM (RAM)

Claims (6)

A serial ROM in which a print processing program and print processing data are recorded;
RAM,
A copy unit that reads the print processing program and the print processing data recorded in the serial ROM and copies them to the RAM based on the activation of the image forming apparatus;
A print unit that executes print processing based on the print processing program and the print processing data copied to the RAM;
When there is a print request, there is no need to determine whether or not there is an unnecessary part in the print processing executed by the print request in the print processing program and the print processing data copied to the RAM. A partial judgment unit;
An image forming apparatus comprising: a deletion unit that deletes an unnecessary part from the RAM when the unnecessary part determination unit determines that there is an unnecessary part. 2. The image according to claim 1, further comprising a re-copying unit that reads an unnecessary part deleted by the deleting unit from the serial ROM after the printing process executed by the print request is completed and re-copys the data to the RAM. Forming equipment. The unnecessary portion determination unit determines whether or not the special function program or data included in the print processing program and the print processing data is unnecessary in the print processing executed by the print request. The image forming apparatus according to claim 2. The unnecessary part determination unit determines whether or not the font data included in the print processing program and the print processing data is unnecessary in the print processing executed by the print request. An image forming apparatus according to claim 1. A free capacity determination unit that determines whether or not there is a possibility that the free capacity of the RAM is insufficient in the printing process executed by the print request when the print request is made;
5. The image formation according to claim 1, wherein the unnecessary portion determination unit determines whether or not the unnecessary portion is present when the free space determination unit determines that the free space is insufficient. apparatus. The image forming apparatus according to claim 1, wherein the copying unit preferentially copies the print processing program to the RAM.

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