JP2010028428A - Image processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain real-time processing of a scanner section despite conflict of occupation requests to occupy a bus line for the scanner section, an image holding section and other processing parts, and to prevent a delay in processing in an image processing section of image data outputted from the image holding section and a delay in processing in other processing parts. <P>SOLUTION: A permitting section 83 permits a hard disc drive (HDD) 60 and other processing parts to occupy the bus line BL in a period after a predetermined amount of image data is read by the scanner section 10 until a next predetermined amount of image data is read by the scanner section 10. In this case, the permitting section 83 determines at the end of occupation of the bus line BL by the scanner section 10 whether the HDD 60 is at an appropriate timing for occupying the bus line BL from occupation information while a receiving section 81 receives the occupation request of the HDD 60, and permits the HDD 60 to occupy the bus line BL when it is determined to be at the appropriate occupation timing. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image processing apparatus.

  In recent years, an image processing apparatus in which a scanner unit, an image processing unit, a hard disk drive unit (HDD), and a main memory are interconnected via a bus line is known. In such an image processing apparatus, the image processing unit performs predetermined image processing on the image data read by the scanner unit and transfers the image data to the main memory, and performs predetermined image processing on the image data output from the HDD. And output to the main memory.

  Here, the image processing unit is required to perform image processing on the image data from the scanner unit with a performance satisfying the reading linear velocity of the scanner unit, that is, to process in real time. On the other hand, it is not required to process image data from the HDD on a best effort basis, that is, to perform image processing at the maximum processing speed.

  Therefore, when the conventional image processing apparatus competes between the scanner unit and the HDD, the scanner unit needs to perform real-time processing on the image data, and the scanner unit reads a predetermined amount of image data. Each time, the scanner unit occupies the bus line, and the image processing unit processes a predetermined amount of image data. Then, when the processing of the predetermined amount of image data by the image processing unit is finished and the image processing unit processes the next predetermined amount of image data, the HDD occupies the bus line, The image data is processed by the image processing unit. In this way, the conventional image processing apparatus sets the priority of the bus line by the scanner unit higher than the priority of the bus line by the HDD, and processes the image data and the image data from the HDD in a time-sharing manner. It was.

Further, in Patent Document 1, in a system in which a plurality of devices are connected to a bus, it is possible to give more bus usage rights to devices that use a bus more frequently than other devices. A bus arbitration method is disclosed.
JP 2002-82900 A

  However, in addition to the scanner unit and the HDD, other processing units that occupy the bus line such as a printing unit that prints image data on recording paper and an interface unit that performs a LAN communication interface are connected to the bus line. . In addition, the bus line occupation requests of the scanner unit, HDD, and other processing units may compete. In this case, if the priority order of the HDD is set higher than the priority order of the other processing units, the right to use the bus line is not easily assigned to the other processing units, and the processing efficiency of the entire image processing apparatus decreases. .

  On the other hand, if the priority order of the other processing units is set higher than the priority order of the HDD, the right to use the bus line is hardly assigned to the HDD, and the processing efficiency of the entire image processing apparatus decreases.

  Moreover, in patent document 1, there is no indication about the process for maintaining real-time processing.

  The object of the present invention is to maintain the real-time processing of the scanner unit and output it from the image holding unit even when the bus line occupation requests among the scanner unit, the image holding unit, and other processing units compete. An object of the present invention is to provide an image processing apparatus capable of suppressing processing delays in image processing units of image data and processing delays in other processing units.

  (1) In the image processing apparatus of the present invention, a scanner unit, an image processing unit, an image holding unit that causes the image processing unit to process held image data, and a control unit are connected to each other via a bus line. The scanner unit occupies the bus line every time a predetermined amount of image data is read in order to cause the image processing unit to process the read image data in real time, and the control unit A receiving unit that receives the bus line occupation request from each of the scanner unit and the image holding unit; and the scanner unit occupies the bus line once for each time the image holding unit occupies the bus line once. A storage unit that preliminarily stores occupancy information indicating whether to occupy, and the reception unit receives an occupancy request of the image holding unit at the end of the bus line occupation by the scanner unit In the case where the image holding unit determines from the occupancy information whether or not it is an occupancy timing that can occupy the bus line, the image holding unit The image holding unit is provided with a permission unit that does not permit the bus line to be occupied when it is determined that the occupation timing is not reached and the occupation timing is not reached.

  According to this configuration, when the reception unit has received the request for occupying the image holding unit at the end of occupying the bus line by the scanner unit, the timing is such that the image holding unit can occupy the bus line. In this case, the image holding unit is permitted to occupy the bus line, and when the occupying timing is not reached, the image holding unit is not permitted to occupy the bus line.

  Accordingly, when the bus line of the image holding unit is not permitted, it is possible to occupy the bus line in other processing units other than the scanner unit and the image holding unit, and the scanner unit, the image holding unit, and other processes. Even if the bus line occupancy request with the image processing unit competes, the real time processing of the scanner unit is maintained, and at the same time, the processing delay in the image processing unit of the image data output from the image holding unit and the other processing unit Processing delay can be suppressed.

  (2) The image processing apparatus further includes a processing unit other than the scanner unit and the image holding unit, and occupies the bus line, and the other processing unit is more connected to the bus line than the image holding unit. In the case where the accepting unit accepts an occupancy request between the image holding unit and the other processing unit at the end of the occupation of the bus line by the scanner unit, When it is determined that it is not the occupation timing of the image holding unit, it is preferable that the other processing unit occupies the bus line.

  According to this configuration, while maintaining the real-time processing of the scanner unit, it is possible to suppress the processing delay in the image processing unit of the image data output from the image holding unit and the processing delay of the other processing units.

  (3) When the image processing unit processes the image data output from the image holding unit on a best effort basis, and the permission unit permits the image holding unit to occupy the bus line, the scanner unit Next, it is preferable to calculate the maximum amount of data that can be processed by the image data within the time until the bus line is occupied, and to output the calculated amount of image data to the image holding unit.

  According to this configuration, both real-time processing and best effort processing can be achieved.

  (4) The image holding unit is preferably a hard disk drive that holds image data.

  According to this configuration, it is possible to suppress delay in processing of image data output from the hard disk drive.

  According to the present invention, even if the bus line occupation requests among the scanner unit, the image holding unit, and the other processing units compete, the real-time processing of the scanner unit is maintained and at the same time output from the image holding unit. It is possible to suppress processing delays in the image processing unit of image data and processing delays in other processing units.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Hereinafter, a case where the image processing apparatus of the present invention is applied to an image forming apparatus such as a digital multifunction peripheral, a network printer, and a copier will be described as an example. FIG. 1 is a schematic side view mainly showing the mechanical configuration of the image forming apparatus. The image forming apparatus includes a main body unit 200, a sheet post-processing unit 300 disposed on the left side of the main body unit 200, an operation unit 400 for a user to input various operation commands and the like, and an upper part of the main body unit 200. The document reading unit 500 is arranged, and the document feeding unit 600 is arranged above the document reading unit 500.

  The operation unit 400 includes an operation panel 401, a start key 402, a numeric keypad 403, and the like. The operation panel 401 displays various operation screens and various operation buttons for the user to input various operation commands. The start key 402 is used for the user to input a print execution command and the like, and the ten key 403 is used for inputting the number of copies to be printed.

  The document feeding unit 600 includes a document placement unit 601, a document discharge unit 602, a paper feed roller 603, a document transport unit 604, a contact glass 605, and the like, and the document reading unit 500 includes a scanner 501 and the like. The paper feed roller 603 feeds out the original set on the original placement unit 601, and the original transport unit 604 transports the fed originals one by one on the scanner 501. The scanner 501 sequentially reads the conveyed document, and the read document is discharged to the document discharge unit 602. In addition, when reading a document placed on the contact glass 605, the scanner 501 slides in the A direction to read the document.

  The main body 200 includes a plurality of paper feed cassettes 201, a plurality of paper feed rollers 202, a transfer roller 203, a photosensitive drum 204, an exposure device 205, a developing device 206, a fixing roller 208, a discharge port 209, and a discharge tray 210. .

  The photosensitive drum 204 is uniformly charged by a charging device (not shown) while rotating in the direction of the arrow. The exposure device 205 converts the modulation signal generated based on the image data of the document read by the document reading unit 500 into a laser beam and outputs it, and forms an electrostatic latent image on the photosensitive drum 204. The developing device 206 supplies a developer to the photosensitive drum 204 to form a toner image. Here, the exposure device 205 includes a laser light source that outputs laser light, a polygon mirror that scans the laser light output from the laser light source in the main scanning direction, which is the longitudinal direction of the photosensitive drum 204, and the like. The photosensitive drum 204 is exposed by driving the laser light source in accordance with a PWM signal having a pulse width corresponding to the gradation value of each pixel constituting the pixel.

  On the other hand, the paper feeding roller 202 pulls out the recording paper from the paper feeding cassette 201 in which the recording paper is stored, and conveys the drawn recording paper to the transfer roller 203. The transfer roller 203 transfers the toner image on the photosensitive drum 204 to the conveyed recording paper. The recording paper to which the toner image has been transferred is conveyed to the fixing roller 208, and the fixing roller 208 heats and transfers the transferred toner image to the recording paper. Thereafter, the recording paper is conveyed to the discharge port 209 and carried into the paper post-processing unit 300. The recording paper is also discharged to the discharge tray 210 as necessary.

  The paper post-processing unit 300 includes a carry-in port 301, a recording paper transport unit 302, a carry-out port 303, a stack tray 304, and the like. The recording paper transport unit 302 sequentially transports the recording paper carried into the carry-in port 301 from the discharge port 209 and finally ejects the recording paper from the carry-out port 303 to the stack tray 304. The stack tray 304 is configured to move up and down in the direction of the arrow in accordance with the number of recording sheets stacked from the carry-out port 303.

  FIG. 2 is a block diagram showing an electrical configuration of the image forming apparatus shown in FIG. The image forming apparatus includes a scanner unit 10, an image processing unit 20, a printing unit 30, an interface unit 40, a main memory 50, a hard disk drive unit (HDD) 60 as an image holding unit, an operation unit 70, and a control unit 80. ing. The scanner unit 10 to the control unit 80 are connected to each other via a bus line BL. In the present embodiment, the scanner unit 10, the image processing unit 20, the printing unit 30, the interface unit 40, and the HDD 60 are referred to as processing units, and among these processing units, the scanner unit 10, the image processing unit 20, and the HDD 60. The other processing units (printing unit 30 and interface unit 40) are referred to as “other processing units”.

  The scanner unit 10 includes the document reading unit 500 shown in FIG. 1, reads a document, and outputs image data to the bus line BL. The image processing unit 20 performs predetermined image processing on the image data read by the scanner unit 10. In addition, the image processing unit 20 performs predetermined image processing on the image data output from the HDD 60. Here, the predetermined image processing performed on the image data by the image processing unit 20 includes gamma conversion, shading correction, compression / decompression processing, white balance correction, and the like. Further, the image processing unit 20 performs real-time processing on the image data read by the scanner unit 10 and processes image data output from the HDD 60 on a best effort basis.

  The printing unit 30 includes the photosensitive drum 204, the exposure device 205, the developing device 206, and the like shown in FIG. 1, and prints image data on recording paper.

  The interface unit 40 includes a communication device that communicates with a computer connected via a LAN, and receives data flowing through the LAN in accordance with the LAN communication protocol and outputs data to the LAN.

  The main memory 50 is configured by a DRAM such as a DDR-DIMM (Double-Data-Rate-Synchronous Dynamic Random Access Memory-Dual Inline Memory Module), and the image output from the scanner unit 10, the image processing unit 20, and the HDD 60. Data and various data are temporarily stored.

  The HDD 60 stores image data received by the interface unit 40. The HDD 60 stores image data read by the scanner unit 10 and instructed to be stored in the HDD 60 or image data received by the interface unit 40.

  The operation unit 70 includes the operation unit 400 illustrated in FIG. 1 and accepts various operation inputs from the user. In the present embodiment, in particular, the operation unit 70 receives an operation input from a user for setting occupation information described later.

  The control unit 80 includes, for example, a CPU and a rewritable nonvolatile memory (for example, EEPROM), and controls the entire image forming apparatus. In the present embodiment, the control unit 80 includes functions of a reception unit 81, an occupation information storage unit 82, a permission unit 83, and a request queue 84. These functions are realized by the control unit 80 executing a control program stored in, for example, an EEPROM.

  The receiving unit 81 receives a request for occupying the bus line BL from each processing unit. Here, the control unit 80 and each processing unit are connected via an occupancy request line for flowing an occupancy request provided separately from the bus line BL, and the reception unit 81 is connected to each processing unit. An occupation request is received via this occupation request line.

  The occupation information storage unit 82 stores in advance occupation information indicating how many times the scanner unit 10 occupies the bus line BL every time the HDD 60 occupies the bus line BL. Here, examples of the occupancy information include “scanner unit-2 times per HDD-1 time”, “scanner unit-3 times per HDD-1 time”, and the like. The occupation information is information set by the user using the operation unit 70.

  When the accepting unit 81 accepts an occupancy request from a processing unit in the accepting unit 81, if the bus line BL is free, the permitting unit 83 occupies the bus line BL in the processing unit, and the bus line BL must be free. For example, occupancy waiting information indicating that the processing unit is waiting to occupy the bus line BL is generated and stored in the request queue 84. When the processing unit can occupy the bus line BL, Delete the occupation wait information.

  Further, when the occupancy waiting information is stored in the request queue 84 when the occupancy of the bus line BL by a certain processing unit is completed, the permission unit 83 occupies the bus line BL in the processing unit corresponding to the occupancy waiting information. Let

  Here, when a plurality of occupancy wait information is stored in the request queue 84, the permission unit 83 occupies the bus line BL according to the priority order of the bus line BL predetermined for each processing unit. A processing unit that can be used is determined, and the bus line BL is occupied by the processing unit.

  In the present embodiment, the priority order of the bus line BL is the highest in the scanner unit 10, the HDD 60 next, and the print unit 30 and the interface unit 40, which are other processing units, have a lower priority than the HDD 60. Further, the image data read by the scanner unit 10 is required to be processed in real time.

  Therefore, the permission unit 83 occupies the bus line BL in the scanner unit 10 every time the scanner unit 10 reads a predetermined amount of image data in order to cause the image processing unit 20 to process the image data read by the scanner unit 10 in real time. Let

  Then, the permission unit 83 causes the HDD 60 and other processing units to occupy the bus line BL during the time from when the scanner unit 10 reads a predetermined amount of image data until the next predetermined amount of image data is read.

  In this case, the permission unit 83 has an occupation timing at which the HDD 60 can occupy the bus line BL when the reception unit 81 accepts an occupancy request for the HDD 60 when the scanner unit 10 occupies the bus line BL. If it is determined from the occupancy information and it is determined that the occupancy timing is reached, the HDD 60 is permitted to occupy the bus line BL. If it is determined that the occupancy timing is not reached, the HDD 60 determines whether the bus line BL is occupied. Do not allow occupancy.

  As the predetermined amount of image data, for example, the image processing unit 20 is in the interval between the time when the scanner unit 10 outputs the predetermined amount of image data and the time when the next predetermined amount of image data is output. A data amount that can process a fixed amount of image data and store it in the main memory 50 can be employed.

  FIG. 3 shows a timing chart of the scanner unit 10 and the image processing unit 20. The upper part of FIG. 3 shows the timing of reading a predetermined amount of image by the scanner unit 10, the middle part shows the timing at which the image processing unit 20 processes the predetermined amount of image data read by the scanner unit 10, and the lower part of FIG. The timing at which the image processing unit 20 processes the image data output from the HDD 60 is shown.

  At timing T1, the scanner unit 10 starts reading image data. Next, at timing T2, the scanner unit 10 outputs an occupation request to the control unit 80 when reading of the first predetermined amount of image data (hereinafter referred to as “first image data”) is completed. The accepting unit 81 accepts this occupation request.

  At timing T2, the permission unit 83 causes the scanner unit 10 to occupy the bus line BL. At this time, the scanner unit 10 stores the first image data read in order to use the main memory 50 as a work area of the image processing unit 20 in the main memory 50. Then, the image processing unit 20 reads the first image data from the main memory 50 and performs image processing as necessary. Then, the image processing unit 20 stores the first image data that has been processed in the main memory 50.

  At timing T2, the scanner unit 10 starts reading the second image data that is the next predetermined amount of image data.

  Next, at timing T3, when the processing of the first image data is completed, the image processing unit 20 outputs a processing end notification to the control unit 80, and the permission unit 83 occupies the bus line BL by the scanner unit 10. End.

  Here, at timing T 3, it is assumed that the waiting information from the HDD 60 is stored in the request queue 84. That is, it is assumed that the accepting unit 81 accepts an occupation request from the HDD 60.

  Therefore, the permission unit 83 determines from the occupancy information stored in the occupancy information storage unit 82 whether or not it is an occupancy timing at which the HDD 60 can occupy the bus line BL.

  In the present timing chart, the occupation information is “scanner unit—two times per HDD—one time”. In this case, the image processing unit 20 processes the image data from the HDD 60 once, while processing the image data of the scanner unit 10 twice. That is, the image processing unit 20 processes the two image data of the first image data and the second image data from the scanner unit 10, that is, the 2nth (n is a positive integer) th. The image data from the HDD 60 can be processed only after the image data is processed.

  Accordingly, since the timing T3 is processed only for the first image data and is not the timing for processing the image data from the HDD 60, the permission unit 83 does not occupy the bus line BL in the HDD 60 at the timing T3. .

  In this case, it is assumed that occupation wait information from another processing unit (for example, the interface unit 40) is stored in the request queue 84 at timing T3. Then, the permission unit 83 causes the interface unit 40 to occupy the bus line BL at the timing T3.

  As a result, it is possible to avoid a situation where another processing unit having a lower priority of the bus line BL than the HDD 60 cannot easily occupy the bus line BL.

  Next, at timing T4, the permission unit 83 causes the scanner unit 10 to occupy the bus line BL, and causes the image processing unit 20 to process the second image data. Next, at timing T <b> 5, the HDD 60 occupation wait information is stored in the request queue 84, and the timing T <b> 5 is the timing at which the HDD 60 occupies the bus line BL. Occupy. As a result, the image processing unit 20 processes the image data X output from the HDD 60.

  Here, the image processing unit 20 may process the image data from the HDD 60 on a best effort basis. Therefore, the permission unit 83 calculates the maximum data amount of image data that can be processed by the image processing unit 20 within the period of timings T <b> 5 to T <b> 7 and notifies the HDD 60. Then, the HDD 60 stores the image data for the notified data amount in the main memory 50 as the image data X. Then, the image processing unit 20 may read the image data X from the main memory 50 as necessary and perform image processing. Then, the image processing unit 20 may store the processed image data X in the main memory 50 again when the processing of the image data X is completed.

  The permission unit 83 may calculate the data amount of the image data X from the period from the timing T5 to T7 and a predetermined processing speed of the image processing unit 20.

  The timing T5 is the processing timing of the image data from the HDD 60, and the priority order of the bus lines BL of the HDD 60 is higher than the priority orders of the other processing units. Therefore, at timing T5, even if request processing information of another processing unit is stored in the request queue 84 in addition to the request waiting information of the HDD 60, the permission unit 83 causes the HDD 60 to occupy the bus line BL.

  As a result, it is possible to avoid a situation in which the HDD 60 can hardly occupy the bus line BL.

  Next, at timing T6, when the processing of the image data X ends, the image processing unit 20 outputs a processing end notification to the control unit 80, and the permission unit 83 ends the occupation of the bus line BL by the HDD 60.

  Thereafter, the third image data is processed by the image processing unit 20 in the period of timing T7-T8, and the fourth image data is processed by the image processing unit 20 in the period of timing T9-T10.

  Further, at timing T8, since it is not the occupation timing of the bus line BL of the HDD 60, the permission unit 83 does not cause the HDD 60 to occupy the bus line BL. On the other hand, at timing T <b> 10, since the timing for occupying the bus line BL of the HDD 60 is reached, the permission unit 83 causes the HDD 60 to occupy the bus line BL.

  Then, the HDD 60 calculates the maximum amount of image data that can be processed by the image processing unit 20 within the period T10-T12, outputs the calculated data amount to the main memory 50 as the image data Y, and the image processing unit 20 To process the image data Y.

  Thus, according to the present image processing apparatus, when the accepting unit 81 accepts the occupancy request for the HDD 60 when the scanner unit 10 finishes occupying the bus line BL, the HDD 60 can occupy the bus line BL. When the occupation timing is reached, the HDD 60 is permitted to occupy the bus line BL. When the occupation timing is not reached, the HDD 60 is not permitted to occupy the bus line BL.

  Accordingly, when the occupation of the bus line BL of the HDD 60 is not permitted, the bus line BL can be occupied by other processing units other than the scanner unit 10 and the HDD 60, and the scanner unit 10, the HDD 60, the other processing units, Even when the bus line occupation requests conflict, the real time processing of the scanner unit 10 is maintained, and at the same time, the processing delay of the image processing unit 20 of the image data output from the HDD 60 and the processing of other processing units Delay can be suppressed.

  In the above description, the occupation information is exemplified by “scanner unit-2 times per HDD-1”, but is not limited to this, and “scanner unit-1 time per HDD-1”, “HDD-1 Other information such as “scanner unit for 3 times”, “scanner unit for 4 HDD times—4 times”, etc. may be adopted.

  For example, when “scanner unit-3 times per HDD—1” is employed, the timing T8 shown in FIG. 3, that is, the image processing unit 20 finishes processing the 3n-th (n is a positive integer) image data. The time when the bus line BL of the HDD 60 is occupied becomes.

1 is a schematic side view mainly showing a mechanical configuration of an image forming apparatus. FIG. 2 is a block diagram illustrating an electrical configuration of the image forming apparatus illustrated in FIG. 1. 3 shows a timing chart of the scanner unit and the image processing unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Scanner part 20 Image processing part 30 Printing part 40 Interface part 50 Main memory 60 HDD
70 operation unit 80 control unit 81 reception unit 82 occupancy information storage unit 83 permission unit 84 request key

Claims (4)

An image processing apparatus in which a scanner unit, an image processing unit, an image holding unit that causes the image processing unit to process image data to be held, and a control unit are connected to each other via a bus line,
The scanner unit occupies the bus line every time a predetermined amount of image data is read in order to cause the image processing unit to process the read image data in real time.
The controller is
A reception unit that receives the bus line occupation request from each of the scanner unit and the image holding unit;
A storage unit that pre-stores occupancy information indicating how many times the scanner unit occupies the bus line per time the image holding unit occupies the bus line;
Whether the image holding unit can occupy the bus line when the receiving unit has received an occupancy request for the image holding unit at the end of the bus line occupation by the scanner unit If it is determined from the occupancy information and it is determined that the occupancy timing is reached, the image holding unit is allowed to occupy the bus line, and if it is determined that the occupancy timing is not reached, the image An image processing apparatus comprising: a permission unit that does not allow the holding of the bus line to the holding unit. A processing unit other than the scanner unit and the image holding unit, further comprising another processing unit that occupies the bus line,
The other processing unit is set to have a lower priority of the bus line than the image holding unit,
The permission unit, when the reception unit has received an occupation request between the image holding unit and the other processing unit at the end of occupation of the bus line by the scanner unit, the occupation timing of the image holding unit The image processing apparatus according to claim 1, wherein if it is determined that the bus line is not, the other processing unit occupies the bus line. The image processing unit processes the image data output from the image holding unit at a best effort,
When the permission unit permits the image holding unit to occupy the bus line, the maximum amount of data that the image data can process in the time until the scanner unit occupies the bus line next time The image processing apparatus according to claim 1, wherein the image processing unit outputs the image data having the calculated data amount to the image holding unit.   The image processing apparatus according to claim 1, wherein the image holding unit is a hard disk drive that holds image data.

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