JP5862174B2 - Image information transfer apparatus, image processing apparatus, and image information transfer control method - Google Patents

Description

  The present invention relates to an image information transfer device, an image processing device, and an image information transfer control method, and more particularly to processing when a predetermined amount of images read by scanning are accumulated and transferred to a memory in a batch.

  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 scanner used for digitizing information, images read by scanning are generated at regular intervals in units of lines. Thus, images generated at regular intervals (hereinafter referred to as line data) must be transferred to the memory at regular intervals. If this is not completed, the line data at the next timing is used. Untransferred line data is overwritten, resulting in a defective abnormal image.

  Similarly, in a printer used for outputting digitized information, it is necessary to output image data to be image-formed or output, that is, line data, to a plotter for image formation output at regular intervals in line units. If the line data is not output to the plotter at regular intervals, the preparation of the image to be formed is not in time for the paper transport speed in the plotter, and the image of the line is not formed correctly and becomes an abnormal image.

  In a multi-function peripheral including a plurality of image processing functions, other image processing functions are included as a bus master in addition to a scanner and a plotter, and each bus master accesses a shared memory and executes each function. In the multi-function peripheral, in order to satisfy the above-described restrictions, by setting a high priority to the memory access of the scanner and plotter, control is performed so as to avoid problems while arbitrating access requests of each bus master. (For example, refer to Patent Document 1).

  The memory access by the scanner and the plotter occurs at a constant interval as described above, that is, every line interval of the image, and the actual memory access period is shorter than the line interval. For this reason, the other bus masters with lower priorities execute the memory access in the period up to the timing of the next line interval after the memory access by the scanner and the plotter is completed. That is, when the arbitration method disclosed in Patent Document 1 is used, even another bus master having a lower priority than the scanner and the plotter can access the memory in order at every line interval.

  In recent years, a scanner that can simultaneously read both sides of a document is sometimes used. In such a scanner, a method of storing a read image on one side or both sides in a local memory and transferring one page at a time when an image for one page is accumulated is being studied. Yes.

  When such an image transfer method is used in a conventional bus arbitration method, the bus is occupied by the scanner while image information for one page is transferred to the memory. As a result, the period during which other bus masters cannot access the memory becomes longer, and the image processing function realized by the other bus masters is hindered.

  As another bus master, for example, there is an image processing unit that realizes a function of processing an image input from a scanner to generate an image for storage, a function of generating an image for image formation output by a plotter, and the like. . When the period during which the image processing unit is inaccessible to the memory becomes long, the period during which the image information cannot be read out and the image information cannot be read out becomes long although the image information to be processed is stored in the memory. Problems arise.

  The above-described problem is particularly noticeable in a scanner that can simultaneously read both sides of a document. However, the present invention is not limited to this, and a scanned image for one page is stored in a local memory, and then the memory for one page is stored together. Similarly, it can be a problem. Further, the range of images stored in the local memory is not limited to one page, and can be similarly a problem if the number of lines exceeds a predetermined value such that memory access by another bus master is impossible for a long period of time. .

  The present invention has been made in consideration of the above situation, and in a case where a predetermined amount of image information read and generated by scanning is accumulated and then transferred to a memory together, another bus is used. The object is to maintain the processing efficiency of the image processing function by the master.

  In order to solve the above-described problem, according to one aspect of the present invention, read image information input as line data for each main scanning line from an image reading device is controlled by controlling access to a main storage device by a plurality of devices. An image information transfer device for transferring to a main storage device, wherein the access control unit controls an access request to the main storage device from each of the plurality of devices in accordance with a priority set for each of the plurality of devices. A transfer amount counting unit that counts the amount of information of the read image information transferred to the main storage device, and a timer count that counts a period after the transfer of the read image information to the main storage device is started And a priority setting unit that sets a priority of a device related to the image reading device in the access control unit, and the priority setting unit includes the image At the start of transfer of the read image information input from the image capturing device to the main storage device, the priority of the device related to the image reading device is set higher than that of other devices and transferred to the main storage device When the count value of the information amount of the read image information reaches an information amount corresponding to a predetermined number of lines, a priority of a device related to the image reading device is set lower than other devices, and the reading When the count value of the period after the transfer of the image information to the main storage device reaches a line cycle corresponding to a predetermined number of lines, the priority of the device related to the image reading device is changed to another It is characterized by being set higher than the device.

  Another aspect of the present invention is an image processing device including the image information transfer device.

  According to still another aspect of the present invention, access to the main storage device by a plurality of devices is controlled, and read image information input from the image reading device as line data for each main scanning line is stored in the main storage device. An image information transfer control method for transferring, wherein an access request to each of the main storage devices from each of the plurality of devices is controlled in accordance with a priority set for each of the plurality of devices, and from the image reading device At the start of transfer of the input read image information to the main storage device, the priority of a device related to the image reading device is set higher than other devices, and the read image transferred to the main storage device The amount of information is counted, the period from the start of transfer of the read image information to the main storage device is counted, and the read image transferred to the main storage device When the count value of the information amount of the information reaches the information amount corresponding to the predetermined number of lines, the priority of the device related to the image reading device is set lower than other devices, and the read image information When the count value of the period from the start of transfer to the main storage device reaches a line period corresponding to a predetermined number of lines, the priority of the device related to the image reading device is set to be higher than that of other devices. It is characterized by being set high.

  According to the present invention, in a case where a predetermined amount of image information read and generated by scanning is accumulated and then transferred to a memory at a time, the processing efficiency of the image processing function by another bus master is maintained. can do.

1 is a diagram illustrating an overall configuration of an image processing apparatus according to an embodiment of the present invention. It is a figure which shows the structure of the controller which concerns on embodiment of this invention. It is a figure which shows the relationship between the line period and memory access timing which concern on embodiment of this invention. It is a figure which shows the relationship between a line period and memory access timing in the case of transferring the stored read image information to a memory collectively. It is a flowchart which shows operation | movement of the controller which concerns on embodiment of this invention. It is a figure which shows the structure of the controller which concerns on other embodiment of this invention. It is a figure which shows the relationship between the line period and memory access timing which concern on other embodiment of this invention. It is a flowchart which shows operation | movement of the controller 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 embodiment, an image processing apparatus as a multifunction machine including a scanner and a plotter will be described as an example. FIG. 1 is a block diagram showing an overall configuration of an image processing apparatus 1 according to the present embodiment. As shown in FIG. 1, the image processing apparatus 1 according to the present embodiment includes a controller 100, a scanner unit 200, and a plotter unit 300.

  The controller 100 is a main part of the image processing apparatus 1, and a scanner image transfer apparatus 101, a plotter image transfer apparatus 102, a CPU (Central Processing Unit) 103, an image processing unit 104, and a shared memory 105 are connected via a bus 106. Has been configured. The bus 106 is controlled by an arbiter 107 that arbitrates an access request to the shared memory 105 from each bus master and controls the access order.

  The scanner image transfer apparatus 101 acquires image information generated by reading an original in the scanner unit 200 and stores it in the shared memory 105. At that time, the scanner image transfer apparatus 101 issues a memory access request to the arbiter 107, and when the arbiter 107 permits the memory access, the scanner image transfer apparatus 101 stores the image information in the shared memory 105. That is, the arbiter 107 functions as an image information transfer device. The arbitration processing of the access request by the arbiter 107 when the scanner image transfer apparatus 101 stores the image information in the shared memory 105 is one of the gist according to the present embodiment.

  The plotter image transfer apparatus 102 reads image information from the shared memory 105 and inputs the image information to the plotter unit 300 in order to cause the plotter unit 300 to perform image formation output. At that time, the plotter image transfer apparatus 102 makes a memory access request to the arbiter 107, and when the arbiter 107 permits the memory access, the plotter image transfer apparatus 102 reads the image information from the shared memory 105 and inputs the image information to the plotter unit 300. Run.

  The CPU 103 is an arithmetic device for controlling the operation of the entire controller 100. The image processing unit 104 has a function of processing image information generated by reading a document by the scanner unit 200 to generate an image for storage, a function of generating an image for image formation output by the plotter unit 300, and the like. Run.

  The shared memory 105 is a nonvolatile storage medium that can read and write information at high speed, and is realized by a RAM (Random Access Memory). The shared memory 105 is loaded with programs for the CPU 103 to implement various functions, a work area for temporarily storing data processed by the CPU 103, and the scanner unit 200 and the plotter unit 300 as described above. It is used as a primary storage area for image information exchanged between the two.

  The scanner unit 200 is an image reading device that optically scans and reads a document to generate image information, and includes a scanner 201, an image input device 202, and a local memory 203. The scanner 201 is an image reading unit including a photoelectric conversion element that converts optical information into an electrical signal. The scanner 201 according to the present embodiment includes a mechanism that can simultaneously read the front surface and the back surface of a document.

  The image input device 202 transmits the read image information generated by the scanner 201 to the scanner image transfer device 101 of the controller 100. Here, as described above, the scanner unit 200 according to the present embodiment has a function of simultaneously reading both sides of a document. Then, the image input device 202 transmits the read image on one side of the document to the scanner image transfer device 101 in real time as line data for each main scanning line, and stores the read image on the other side in the local memory 203. Then, after the transmission of the read image on one side is completed, it is transmitted collectively. A process on the controller 100 side corresponding to this process is one of the gist according to the present embodiment.

  As described above, the local memory 203 is a storage medium that temporarily stores the read image information on the surface that the image input device 202 does not transmit to the controller in real time. -RAM (Non Volatile-RAM) etc. are used.

  In this embodiment, as described above, the read image on one side of the document is transmitted to the controller 100 in real time, and the read image on the other side is stored in the local memory 203 and then transmitted together. The This is because the information transfer speed of the interface between the scanner unit 200 and the controller 100, the information transfer speed of the bus 106 in the controller 100, and the line data generated for each line cycle of image reading by the scanner 201, that is, This depends on the relationship with the amount of read image information read for each line cycle.

  For example, if the amount of line data per line cycle exceeds the transferable capacity depending on the information transfer speed of the interface between the scanner unit 200 and the controller 100 or the information transfer speed of the bus 106 in the controller 100, the information Deficiency will occur. Even if the amount of line data per line cycle is within the capacity that can be transferred depending on the information transfer speed of the interface between the scanner unit 200 and the controller 100 or the information transfer speed of the bus 106 in the controller 100, In the case of occupying a part, it is possible that a problem occurs due to the relationship with other modules.

  In order to avoid such a problem, at least one side of the document is not transferred in real time, but is once stored in the local memory 203 and transferred to the controller 100 side. In addition, since the amount of line data for each line cycle tends to increase due to the advancement of the scanner unit 200, not only one side of the document but also the read images on both sides are stored in the local memory 203. You may make it transfer later.

  The plotter unit 300 is an image forming apparatus that performs image formation output on a sheet, and includes a plotter 301 and an image output apparatus 302. The plotter 301 is an engine that executes image formation output based on input image information, and an electrophotographic image forming mechanism or an ink jet image forming mechanism is used. The image output device 302 acquires image information input from the plotter image transfer device 102 and controls the plotter 301 to execute image formation output.

  When such an image processing apparatus 1 operates as a copying machine, first, the scanner unit 200 scans a document based on a user operation, and generates read image information. The read image information generated by the scanner unit 200 is stored in the shared memory 105 by real-time transfer as described above or transfer after being accumulated in the local memory 203.

  When the read image information is stored in the shared memory 105, the image processing unit 104 executes image processing for generating image information for image formation output based on the read image information stored in the shared memory 105. . Image information for image formation output generated by image processing by the image processing unit 104 is transmitted to the plotter unit 300 via the plotter image transfer apparatus 102. As a result, image forming output is executed in the plotter unit 300.

  In FIG. 1, the image processing apparatus 1 including the scanner unit 200 and the plotter unit 300 and functioning at least as a copying machine is described as an example. In addition, for example, a network I / F or the like is provided, and a function as a printer that receives a print job from a PC (Personal Computer) and executes image formation output, or a storage device such as an HDD (Hard Disk Drive) It is also possible to provide a function as a server for accumulating image information generated by scanning.

  Next, memory access control via the bus 106 in the controller 100 will be described. FIG. 2 is a diagram showing details of the memory access control via the bus 106 by the arbiter 107 according to the present embodiment. As shown in FIG. 2, the arbiter 107 according to the present embodiment includes a memory access control unit 108, a data counter 109, and a priority control unit 110 therein.

  As shown in FIG. 2, the memory access control unit 108 has a plurality of ports, and each port is one of the bus masters such as the scanner image transfer device 101, the plotter image transfer device 102, the image processing unit 104, and the CPU 103. Is connected. Further, it is connected to the shared memory 105 via the bus 106. Thus, the memory access control unit 108 functions as an access control unit that controls the exchange of information between each bus master and the shared memory 105 in response to a memory access request from the bus master connected to each port.

  The memory access priority is set for each of the plurality of ports of the memory access control unit 108. The memory access control unit 108 is connected to each bus master in response to a memory access request from each bus master. Arbitration is performed so that the memory access right is granted based on the priority of the existing port.

  The data counter 109 monitors the data transfer of the port connected to the scanner image transfer apparatus 101 among the respective ports included in the memory access control unit 108 and counts the data transfer amount. And a line period counter for counting the line period. That is, the data counter 109 according to the present embodiment includes a data transfer amount counter that functions as a transfer amount count unit and a line cycle counter that functions as a timer count unit. The data counter 109 outputs a signal corresponding to the count results of the data transfer amount counter and the line cycle counter to the priority control unit 110.

  The priority control unit 110 is a priority setting unit that controls the memory access priority of the port to which the scanner image transfer apparatus 101 is connected among the ports included in the memory access control unit 108. In principle, the memory access priority of each port included in the memory access control unit 108 is fixed according to the bus master connected to each port. In contrast, the gist of the present embodiment is that the memory access priority of the port to which the scanner image transfer apparatus 101 is connected is changed according to the processing of the data counter 109 and the priority control unit 110. .

  Next, the relationship between the above-described line cycle and the transfer period of read image information to the shared memory 105 by the scanner image transfer apparatus 101 will be described. FIGS. 3A and 3B show the scanner image transfer apparatus 101 in real time for each line period as line data for each main scanning line in the above-described two modes of transfer of read image information by the image input apparatus 202. It is a figure which shows the case where it transmits to. FIG. 3A is a timing chart showing a case where a read image on one side of a document is transmitted to the scanner image transfer apparatus 101 in real time for each line period as line data for each main scanning line, as described above. is there.

  When scanning is executed in the scanner unit 200, the scanner image transfer apparatus 101 issues a memory access request to the memory access control unit 108 for each line cycle via the image input apparatus 202. In the memory access control unit 108, the memory access priority of the port to which the scanner image transfer apparatus 101 is connected is set to the highest in principle. For this reason, as shown in FIG. 3A, for each line cycle, the scanner image transfer apparatus 101 preferentially transfers one line of line data to the shared memory 105, and thereafter, other than the scanner image transfer apparatus 101. The shared memory 105 is accessed by the module.

  On the other hand, FIG. 3B is a timing chart illustrating an example in which real-time transfer is performed on both sides of the document. In the example of FIG. 3B, when real-time transfer is performed on both sides of a document, the access period of the shared memory 105 permitted to devices other than the scanner image transfer apparatus 101 in the line cycle becomes very short. For this reason, at least one side of the document is subjected to processing for transferring the read image information stored in the local memory 203 later without performing real-time transfer.

  Next, the relationship between the line cycle and the information transfer period from the scanner image transfer apparatus 101 to the shared memory 105 when the read image information stored in the local memory 203 is collectively transferred later will be described with reference to FIG. I will explain. The read image information stored in the local memory 203 is read image information for at least one page. As described above, the memory access priority of the port to which the scanner image transfer apparatus 101 is connected is set to the highest.

  Therefore, when a memory access request is made to transfer the read image information stored in the local memory 203 to the shared memory 105, lines corresponding to the number of lines corresponding to at least one page, as shown in FIG. During the period, the scanner image transfer apparatus 101 occupies the access right to the shared memory 105, and other devices are in a standby state during that period.

  In the state shown in FIG. 4, the device other than the scanner image transfer apparatus 101, for example, the image processing unit 104 accesses the shared memory 105 in which image information is stored even though there is image processing to be executed. Since this is not possible, a state of waiting for processing is generated, which causes a reduction in processing efficiency of the entire image processing apparatus 1 and consequently impairs user convenience. A function provided by the data counter 109 and the priority control unit 110 for solving such a problem is the gist of the present embodiment.

  FIG. 5 is a flowchart showing the operation of the controller 100 related to the read image information transfer operation from the scanner image transfer apparatus 101 to the shared memory 105 according to the present embodiment. The operation shown in FIG. 5 is based on the premise that transfer of read image information stored in the local memory 203 to the shared memory 105 is requested based on control by the CPU 103.

  As shown in FIG. 5, when the transfer of the read image information to the shared memory 105 is started, the CPU 103 initializes the count values of the data transfer amount counter and the line cycle counter of the data counter 109 (S501). Further, the CPU 103 sets the data amount for one line as the count-up value for the data transfer amount counter, and sets the line amount as shown in FIGS. 3A, 3B, and 4 for the line period counter. The period is set as a count-up value (S502). Further, the priority control unit 110 gives the highest priority to the memory access priority of the port 1 of the memory access control unit 108, that is, the port to which the scanner image transfer apparatus 101 is connected, in accordance with the control of the CPU 103, that is, over other bus master devices. High priority is set (S503).

  When the initial setting up to S503 is completed, the CPU 103 notifies the data counter 109 of the start of transfer (S504). As a result, the line period counter of the data counter 109 starts counting of the timer. When the scanner image transfer apparatus 101 starts transferring the read image information input from the scanner unit 200 (S505), the data transfer amount counter of the data counter 109 detects the transfer of the head data of the line data, and the data transfer The amount counting is started (S506).

  The read image information transfer process from the scanner image transfer apparatus 101 to the shared memory 105 is executed for each predetermined data unit. This data unit is, for example, 128 B (bytes). Each time this data unit transfer is completed, the memory access control unit 108 arbitrates the memory access request from each bus master according to the memory access priority of each port, and determines the bus master that permits the memory access. .

  As described above, since the memory access priority of the port 1 to which the scanner image transfer apparatus 101 is connected has the highest priority, when the scanner image transfer apparatus 101 starts transferring the read image information, another bus master. The scanner image transfer apparatus 101 continues to transfer the read image to the shared memory 105, and the data transfer amount counter of the data counter 109 counts the transfer amount. The period counter counts the timer.

  When the data transfer amount counter of the data counter 109 counts the data amount for one line set in S502 (S507 / YES), the CPU 103 that has received the notification reads the read image information stored in the local memory 203. Is completely transferred (S508), and if all the read image information has been transferred (S508 / YES), the process ends. The data transfer amount counter that counts the data amount for one line resets the count value.

  On the other hand, if it is determined in S508 that the transfer of all the read image information has not been completed (S508 / NO), the priority control unit 110 that has received the notification signal from the data counter 109 connects to the scanner image transfer apparatus 101. The memory access priority of the port 1 being set is set to the lowest, that is, a priority lower than that of other bus master devices (S509). Thus, the access request to the shared memory 105 by the scanner image transfer apparatus 101 has a lower priority than the access request from other bus masters, and the read image information is transferred from the scanner image transfer apparatus 101 to the shared memory 105. Substantially stop.

  Thereafter, the line cycle counter of the data counter 109 continues to count the timer, and when the count value of the timer reaches the line cycle set in S502 (S510 / YES), the count value is reset and the line cycle is set. The priority control unit 110 is notified that it has been reached. Thereby, the priority control unit 110 sets the memory access priority of the port 1 set as the lowest in S509 to the highest priority, that is, a priority higher than other bus master devices (S511).

  When the memory access priority of the port 1 is set to the highest priority in the process of S511, the memory access control unit 108 allows the scanner image transfer apparatus 101 to access the memory by the arbitration process, and the scanner image transfer apparatus 101 shares it again. Transfer of the read image information to the memory 105 is started. As a result, the data transfer amount is counted by the data transfer amount counter of the data counter 109. When the data transfer amount counter of the data counter 109 counts the data amount for one line set in S502, the processing from S507 is repeated. Hereinafter, the processing according to the gist of the present embodiment is performed by repeating the processing.

  As a result of such an operation, as shown in FIG. 4, even in the batch transfer operation of the read image information in which the scanner image transfer apparatus 101 originally occupies the memory access right for a long period of time, as in FIG. One line of line data is transferred for each line period. Therefore, as shown in FIG. 3A, the bus master other than the scanner image transfer apparatus 101 does not become inaccessible to the memory for a long time, and the above-described problems can be solved.

  Here, even during the period from S509 to S511, if there is no other bus master requesting access, the scanner image transfer apparatus 101 transfers the read image information. As a result, data for one line may be counted before the line period elapses (S510 / NO) (S512 / YES). In this case, the process proceeds to S508 as in the case of “YES” in S507.

  If “NO” is determined in S508 after “YES” in S512, the process of setting the priority in S509 to the lowest is passed on the flow, but at this point, the priority is already the lowest. Therefore, the process proceeds to S510 without performing any particular process. According to such processing, depending on the state of the access request by another bus master, the state shown in FIG. However, there are few access requests by other bus masters, and the scanner image transfer apparatus 101 does not unnecessarily occupy the bus, so this is not a problem. Thereby, the transfer of the read image information can be completed in a shorter period.

  As described above, by using the arbiter 108 as the image information transfer apparatus according to the present embodiment, a predetermined amount of image information generated by scanning is accumulated and then transferred to the memory collectively. In such a case, it is possible to maintain the processing efficiency of the image processing function by another bus master.

  In FIG. 1, the scanner image transfer apparatus 101, the plotter image transfer apparatus 102, the CPU 103, the image processing unit 104, and the shared memory 105 are all shown as being directly connected to the bus 106, but this is an example. is there. For example, the CPU 103 and the shared memory 105 may be connected to a local bus via a bridge. Even in such a case, the same effect can be obtained by applying the memory access request adjustment processing by the arbiter 107 according to the gist of the present embodiment.

Embodiment 2. FIG.
In the first embodiment, by setting the count value of the data counter 109 to the data amount and line cycle for one line, the read image information stored in the local memory 203 is transferred to the shared memory 105 at once. Even in this case, the case has been described as an example in which a mode in which read image information for one line is transferred for each line period as shown in FIG.

  However, depending on the processing content of the image processing unit 104, the unit of image processing may be every plural lines. For example, when JPEG (Joint Photographic Experts Group) compression is performed, the image processing unit 104 performs image compression processing in units of 16 lines or 8 lines. Therefore, the process cannot be started until a predetermined number of lines of line data are transferred to the shared memory 105. In the case of image rotation processing, the rotation processing cannot be started until the number of sub-scan lines of the block for image rotation is accumulated in the shared memory.

  In such a case, when the mode in which the read image information for one line is transferred for each line period as in the first embodiment, the image processing unit 104 cannot start the process and the inefficient control is performed. turn into. In the present embodiment, a configuration for solving such a problem will be described. In addition, about the structure which attaches | subjects the code | symbol similar to Embodiment 1, it shall show the same or equivalent part as Embodiment 1, and detailed description is abbreviate | omitted.

  FIG. 6 is a diagram showing details of memory access control via the bus 106 by the arbiter 107 according to the present embodiment, and corresponds to FIG. 2 of the first embodiment. As shown in FIG. 6, the arbiter 108 according to the present embodiment has substantially the same configuration as that of the first embodiment, but is different from the first embodiment in that a line number setting unit 111 is included.

  The line number setting unit 111 stores the number of lines for determining the count value of the data transfer amount counter and the line period counter of the data counter 109 in an internal storage medium, and inputs the number of lines to the data counter 109. In the first embodiment, the data amount for one line and the line cycle of one line are set as the count-up value. However, in this embodiment, the data amount for a plurality of lines is set according to the contents of the image processing by the image processing unit 104. The data amount and the line period are set as the count-up value.

  The setting of the number of lines in the line number setting unit 111 is executed by the CPU 103. The CPU 103 can refer to the processing contents of the image processing unit 104 that processes the read image information transferred from the scanner image transfer apparatus 101 to the shared memory 105 when setting the number of lines in the line number setting unit 111. Then, the CPU 103 sets the number of lines in the line number setting unit 111 according to the number of lines in the processing unit in the image processing executed by the image processing unit 104. This makes it possible to automatically realize a suitable number of lines setting.

  Note that the number of lines when the counter setting unit 111 sets the count-up value according to a plurality of lines is, for example, 16 lines or 8 lines in the case of the above-described JPEG compression processing.

  Next, the operation of the controller 100 related to the read image information transfer operation from the scanner image transfer apparatus 101 according to the present embodiment to the shared memory 105 will be described. Also in the present embodiment, processing is executed in the same manner as in FIG. 5 of the first embodiment. Here, in this embodiment, the process in S502 is different.

  In S502 according to the present embodiment, the data counter 109 sets a count-up value according to the control of the CPU 103, but at this time, not the data amount for one line and the line cycle for one line as in the first embodiment. The data amount corresponding to the number of lines set in the counter setting unit 111 and the line period for a plurality of lines are set as the count-up value. Thereafter, the same processing as in FIG. 5 of the first embodiment is executed.

  By such processing, in S507, the transfer of the read image information is repeated until the data amount for the number of lines set in the line number setting unit 111 is transferred. In S510, the memory access priority of the port 1 is maintained at the lowest level until the line cycle for the set number of lines elapses, and when the line cycle for the set number of lines elapses, the port 1 The memory access priority is reset to the highest priority.

  FIG. 7 shows the line period and read image to the shared memory 105 when the operation of the controller 100 related to the transfer operation of the read image information from the scanner image transfer apparatus 101 to the shared memory 105 according to this embodiment is executed. It is a timing chart which shows the relationship with a transfer period. FIG. 7 shows an example in which the number of lines is set to “4” in the line number setting unit 111.

  As shown in FIG. 7, until the line data for four lines is transferred, the transfer of the read image information to the shared memory 105 by the scanner image transfer apparatus 101 is continued. When transfer of line data for four lines is completed, the memory access priority of the port 1 to which the scanner image transfer device 101 is connected becomes the lowest, so that a bus master other than the scanner image transfer device 101 performs memory access. This is a period to be performed, and this state is maintained until the line period for four lines elapses.

  As described above, when the read image information stored in the local memory 203 is collectively transferred to the shared memory 105 by using the arbiter 108 as the image information transfer apparatus according to the present embodiment, the read image The unit for dividing the transfer to the shared memory 105 can be set for each predetermined number of lines. Therefore, when the image processing unit 104 performs image processing for each predetermined number of lines, it is possible to prevent the processing efficiency of other bus masters such as the image processing unit 104 from being lowered.

  In the first and second embodiments, when the read image information stored in the local memory 203 is transferred to the shared memory 105, the operation shown in FIG. In the above description, the timing as shown in FIG. On the other hand, even when the line data is input from the scanner unit 200 in real time for each line period and the timing as shown in FIG. It is possible to transfer the read image to the shared memory 105 with no particular adverse effect in a state in which the function according to the above is enabled.

  In this case, in the period when the transfer of line data for one line is completed and there is no memory access request from the scanner image transfer apparatus 101, the memory access priority of the port 1 becomes the lowest by the function according to this embodiment. It will be set. Thereafter, when the line cycle elapses and the line data is input again from the scanner unit 200, the memory access priority of the port 1 is set to the highest priority by the function according to the present embodiment. In addition, it is possible to transfer the read image information without causing any harmful effects.

  On the other hand, during the above-described real-time transfer, the functions according to the present embodiment, that is, the count process by the data counter 109 and the priority setting process by the priority control unit 110 may be invalidated. In order to invalidate the function according to the present embodiment, at least when the priority control unit 110 performs the processing of S509 in FIG. 5, that is, when read image information for one line or a predetermined number of lines has been transferred. The processing for setting the memory access priority of port 1 to the lowest level may be switched between valid / invalid. Thereby, unnecessary processing can be reduced.

Other embodiments.
In the above embodiment, the case where the memory access priority of the port 1 to which the scanner image transfer apparatus 101 is connected is set to the lowest in S509 of FIG. 5 has been described as an example. Thus, after the read image information for one line is transferred in one line cycle, if there is an access request from another bus master, that is given priority, and if there is no access request from another bus master. The process is such that the read image information is transferred.

  On the other hand, considering the simpler and easier operation of the apparatus as the operation mode of the apparatus, the scanner image transfer apparatus 101 is connected after the read image information for one line is transferred in one line cycle. A mode is also conceivable in which the memory access priority of port 1 is set to zero, that is, memory access by port 1 is prohibited. Hereinafter, such an example will be described.

  FIG. 8 is a flowchart showing the operation of the controller 100 related to the read image information transfer operation from the scanner image transfer apparatus 101 to the shared memory 105 according to this embodiment. As shown in FIG. 8, the processing from S801 to S808 is executed in the same manner as S501 to S508 in FIG.

  If it is determined in step S808 that transfer of all read image information has not been completed (NO in step S808), the priority control unit 110 that has received the paper passing signal from the data counter 109 is connected to the scanner image transfer apparatus 101. The memory access priority of port 1 is set to zero (S809). As a result, the access request to the shared memory 105 by the scanner image transfer apparatus 101 is rejected regardless of whether there is an access request from another bus master.

  Thereafter, when the count value of the line cycle counter of the data counter 109 that continues to count the timer reaches the line cycle (S810 / YES), the priority control unit 110 sets the port 1 set to zero in S809 as in S511. The memory access priority is set to the highest priority, that is, a higher priority than other bus master devices (S811).

  When the memory access priority of port 1 is set to the highest priority in the process of S811, the memory access control unit 108 permits the memory access to the scanner image transfer apparatus 101 by the arbitration process, and the scanner image transfer apparatus 101 shares it again. Transfer of the read image information to the memory 105 is started (S805). Thereafter, the processing according to the gist of the present embodiment is executed by repeating the processing from S805.

  As described above, according to the processing according to the present embodiment, when the read image information for one line is transferred in one line cycle, the memory access by the scanner image transfer apparatus 101 is prohibited during the subsequent line cycle. The Therefore, the state of FIG. 3A and the state of FIG. 3B do not coexist in response to a memory access request by another bus master, and the apparatus operation is stabilized in the state of FIG. Can be made. Further, according to the present embodiment, setting of the memory access priority and the like are not necessary, so that the apparatus configuration and processing can be simplified.

  Note that according to the present embodiment, in S809, the memory access priority of the port 1 to which the scanner image transfer apparatus 101 is connected is set to zero. However, the priority is still set low.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 100 Controller 101 Scanner image transfer apparatus 102 Plotter image transfer apparatus 103 CPU
104 Image processing unit 105 Shared memory 106 Bus 107 Arbiter 108 Memory access control unit 109 Data counter 110 Priority control unit 111 Line number setting unit 200 Scanner unit 201 Scanner 202 Image input device 203 Local memory 300 Plotter unit 301 Plotter 302 Image output device

JP 2000-332924 A

Claims (8)

An image information transfer device that controls access to a main storage device by a plurality of devices and transfers read image information input as line data for each main scanning line from the image reading device to the main storage device,
An access control unit that controls an access request to the main storage device from each of the plurality of devices according to a priority set for each of the plurality of devices;
A transfer amount counter for counting the amount of information of the read image information transferred to the main storage device;
A timer count unit that counts a period from the start of transfer of the read image information to the main storage device;
A priority setting unit for setting a priority of a device related to the image reading device in the access control unit,
The priority setting unit
At the start of transfer of the read image information input from the image reading device to the main storage device, the priority of the device related to the image reading device is set higher than other devices,
When the count value of the information amount of the read image information transferred to the main storage device reaches the information amount corresponding to the predetermined number of lines, the priority of the device related to the image reading device is set to another device. Set lower than
When the count value of the period after the transfer of the read image information to the main storage device reaches a line cycle corresponding to a predetermined number of lines, the priority of the device related to the image reading device is set. An image information transfer apparatus, characterized in that it is set higher than other devices. The priority setting unit
When the count value of the information amount of the read image information transferred to the main storage device reaches the information amount for one line, the priority of the device related to the image reading device is set lower than other devices. Set,
When the count value of the period after the transfer of the read image information to the main storage device reaches a line period of one line, the priority of the device related to the image reading device is set to another device. The image information transfer apparatus according to claim 1, wherein the image information transfer apparatus is set higher than the image information transfer apparatus. A line number setting unit for setting the number of lines for switching the priority of a device related to the image reading apparatus in the access control unit;
The priority setting unit
When the count value of the information amount of the read image information transferred to the main storage device reaches the information amount corresponding to the set number of lines, the priority of the device related to the image reading device is changed. Set lower than your device,
When the count value of the period after the transfer of the read image information to the main storage device reaches a line period corresponding to the set number of lines, the device related to the image reading device The image information transfer apparatus according to claim 1, wherein the priority is set higher than other devices.   The line number setting unit sets the number of lines corresponding to a processing unit of the image processing unit that processes the read image information transferred to the main storage device, in a device related to the image reading device in the access control unit. 4. The image information transfer apparatus according to claim 3, wherein the image information transfer apparatus is set as the number of lines for switching the priority.   The priority setting unit determines the amount of information of the read image information transferred to the main storage device when read image information accumulated in at least one page in the image reading device is input from the image reading device. 5. The device according to claim 1, wherein when a count value reaches an information amount corresponding to a predetermined number of lines, a priority of a device related to the image reading apparatus is set lower than that of another device. The image information transfer apparatus according to claim 1. The priority setting unit is a device related to the image reading device when the count value of the information amount of the read image information transferred to the main storage device reaches an information amount corresponding to a predetermined number of lines. 6. The image information transfer apparatus according to claim 1, wherein a priority of a device related to the image reading apparatus is set so as to prohibit access to the main storage device from a computer.   An image processing apparatus comprising the image information transfer apparatus according to claim 1. An image information transfer control method for controlling access to a main storage device by a plurality of devices and transferring read image information input as line data for each main scanning line from the image reading device to the main storage device,
Control access requests to the main storage from each of the plurality of devices according to the priority set for each of the plurality of devices,
At the start of transfer of the read image information input from the image reading device to the main storage device, the priority of the device related to the image reading device is set higher than other devices,
Count the amount of the read image information transferred to the main storage device,
Count the period from the start of transfer of the read image information to the main storage device,
When the count value of the information amount of the read image information transferred to the main storage device reaches the information amount corresponding to the predetermined number of lines, the priority of the device related to the image reading device is set to another device. Set lower than
When the count value of the period after the transfer of the read image information to the main storage device reaches a line cycle corresponding to a predetermined number of lines, the priority of the device related to the image reading device is set. An image information transfer control method, wherein the image information transfer control method is set higher than other devices.

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