JP2013017117A - Image forming apparatus and frequency control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that can optimize power consumption of a body and an option board such that a rated power is not exceeded, when the option board is loaded.SOLUTION: The image forming apparatus includes: image data acquisition means 43, 22 for acquiring image data; operation reception means 41; output means 42, 12 for outputting image-processed image data; a first central processing unit 15; an interface 23 loadable with a second central processing unit; loading detection means 57 for detecting whether or not the second central processing unit is loaded; a processing determination table 56 in which processing modes are registered in association with image processing; a frequency determination table 58 in which frequencies of the first and second central processing units are registered in association with the processing modes; processing mode determination means 53 for determining the processing mode; frequency determination means 54 for determining the frequencies of the first and second central processing units; first frequency control means 61; and second frequency control means 66.

Description

  The present invention relates to an image forming apparatus to which an option board can be attached.

  A technique for adding functions by adding an option board to an image forming apparatus is conventionally known. The image forming apparatus is entirely controlled by a main controller board, and a power source is connected to the controller board, but the power source of the option board is often the same as that of the controller board.

  Adding the option board increases the total power used by the image forming apparatus. Therefore, it is necessary to accumulate enough power to allow the option board to be added to the device in advance. However, since the power required for the option board is not always constant, if the power is estimated and accumulated, the cost of the image forming apparatus increases.

  In view of this, a technique for controlling the power so as not to exceed the rated power of the controller board even if an option board is added has been considered (for example, see Patent Document 1). Patent Document 1 discloses an image forming apparatus in which an expansion device itself switches the clock frequency according to the power supply capability on the main body side. As a result, two extension devices with low power consumption or one extension device with high functionality and high power consumption can be connected to the main body.

  However, the image forming apparatus disclosed in Patent Document 1 has a problem that the processing speed of the option board decreases because the frequency of the option board is lowered. The option board is mounted to reduce the processing time in addition to the addition of functions, and the option board is preferably operated at a frequency as large as possible.

  In view of the above problems, an object of the present invention is to provide an image forming apparatus capable of optimizing the power consumption of a main body and an option board so that the rated power is not exceeded when the option board is mounted.

    In view of the above-described problems, the present invention provides an image data acquisition unit that acquires image data, an operation reception unit that receives image processing performed on the image data, and an output unit that outputs the image data subjected to image processing. A first central processing unit that performs image processing, an interface on which a second central processing unit that performs image processing can be mounted, and whether the second central processing unit is mounted on the interface Corresponding to the mounting detection means and the image processing, any one of the processing modes of the first central processing unit, the second central processing unit, and the first and second central processing units in parallel is registered. The processing determination table, the frequency determination table in which the frequencies of the first central processing unit and the second central processing unit are registered in association with the processing mode, and the processing determination table based on image processing A processing mode determination unit that determines the processing mode, a frequency determination unit that refers to the frequency determination table based on the processing mode and determines the frequencies of the first and second central processing units, First frequency control means for controlling the frequency of the central processing unit, and second frequency control means for controlling the frequency of the second central processing unit.

  It is possible to provide an image forming apparatus capable of optimizing the power consumption of the main body and the option board so that the rated power is not exceeded when the option board is mounted.

FIG. 3 is an example of a diagram illustrating a frequency control procedure by the image forming apparatus. It is an example of the block diagram of a controller board and an option board. 1 is an example of a functional block diagram of an image forming apparatus. It is a figure which shows an example of a process determination table and a frequency determination table. FIG. 3 is an example of a flowchart illustrating an operation procedure when the image forming apparatus is activated. FIG. 10 is an example of a flowchart for explaining the setting procedure of the CPU of the option board when the option board is activated. FIG. 3 is an example of a flowchart illustrating a frequency setting procedure when the image forming apparatus performs image processing. It is an example of the flowchart figure which shows the procedure which changes to the frequency to which the option board was set. It is an example of the flowchart figure which shows the setting procedure of the frequency after completion | finish of an image process. It is a figure which shows an example of the relationship between a process mode and power consumption. 1 is an example of a functional block diagram of an image forming apparatus. It is an example of the figure which illustrates a power consumption map typically. It is a figure which shows an example of a frequency setting screen.

  Hereinafter, modes for carrying out the present invention will be described.

  FIG. 1 is an example of a diagram illustrating a frequency control procedure performed by the image forming apparatus according to the present exemplary embodiment. When the option board is connected to the image forming apparatus, the controller board and the option board can communicate with each other.

  The software is running on the controller board, and the output method (file format conversion, color conversion, etc.) of the image data output method (hard disk storage, print output with plotter, data transfer to other devices, etc.) The contents of the image processing are determined accordingly. When detecting that the option board is connected, the software of this embodiment determines whether the image processing is performed by the controller board or the option board.

There are the following three types of processing modes to be determined.
(i) Controller board and option board process in parallel
(ii) Processed only by the controller board
(iii) Only the option board processes In the image forming apparatus of this embodiment, in the case of (i) parallel processing, the controller board lowers the CPU frequency of the controller board, and the controller board converts the option board CPU to the option board. Set the frequency. The CPU frequency of the option board to be set is the maximum value or the highest possible value.

  Also, the CPU frequency of the controller board does not decrease to the Min value. This is because if the value is decreased to the Min value, the processing of the controller board will be delayed. Therefore, by reducing the frequency of the controller board without reducing it to the Min value and increasing the frequency of the option board as much as possible, the processing performance of the image forming apparatus can be improved within a range not exceeding the rated power of the image forming apparatus. It can be pulled out to the maximum.

[Configuration example]
FIG. 2 is an example of a configuration diagram of the controller board 20 and the option board 30 in the image forming apparatus 100. A PSU (Power Supply Unit) 40 is connected to the controller board 20, and power to the option board 30 is also supplied from the PSU 40.

  The controller board 20 performs overall control including data processing such as printing, scanner reading, FAX transmission / reception, and network communication. The option board 30 is connected to the controller board 20 and performs image processing requested by the controller board 20. As a result, the load on the controller board 20 is reduced.

  The controller board 20 has two ASICs 11 and 16 and a CPU 15. A scanner unit 43, a plotter unit 42, and an HDD 12 are connected to the ASIC 11. An ASIC 11, an ASIC 16, a RAM 13, and a ROM 14 are connected to the CPU 15. The ASIC 16 is connected with an operation unit 41, an SD I / F 19, a USB I / F 21, a Network I / F 22, a NAND FLASH 17, and an NVRAM 18.

  The scanner unit 43 acquires image data from a scanner (not shown). The scanner, for example, reads a document in the main scanning direction line by line by a color line sensor using a CCD (Charge Coupled Device), moves the document in the sub-scanning direction, and has an image with a predetermined gradation for each RGB. Generate data. The scanner unit 43 corrects image data (shading correction processing, γ correction, filter processing, RGB → RGB color conversion processing, etc.) based on the CCD characteristics of the scanner acquired in advance.

  The plotter unit 42 writes image data to a plotter (not shown). The plotter unit 42 acquires image data from the ASIC 11, converts the image data into RGB → CMYK image data, and then dithers and transfers the image data to the plotter.

  The plotter is, for example, an electrophotographic printing apparatus, and outputs image data by fixing a toner image on a sheet based on CMYK image data. A black and white plotter or an ink jet type plotter that forms an image on a sheet by applying droplets may be used.

  The operation unit 41 is a user I / F unit using a touch panel, hard keys, or the like. In addition to the touch panel controller and the key matrix controller, a CPU (not shown) that controls them is mounted. In the image forming apparatus 100 including the LCD touch panel, the CPU also draws the LCD screen.

  The ASIC 11 acquires image data from the scanner unit 43 or the HDD 12. The ASIC 11 performs various image processing according to the output method and output conditions. After the image processing, the ASIC 11 writes the image data into the HDD 12 and reads out the image data from the HDD 12 when outputting to the plotter or when outputting to the CPU 15.

  The CPU 15 uses the RAM 14 as a work memory based on programs and system data stored in the HDD 12 or the ROM 14, and performs integrated control of the entire image forming apparatus 100. Further, the CPU 15 executes image processing according to the output method and output conditions. For example, when the user sets the conversion of image data to JPEG, sets the conversion to PDF, or sets the OCR processing, the image processing according to the setting content is performed.

  The ASIC 16 is responsible for energy saving control and control with various I / Fs. When a terminal (not shown) transmits print data to the network I / F 22, the ASIC 16 converts the print data into image data and outputs the image data to the CPU 15. The CPU 15 outputs image data to the plotter unit 42 or the HDD 12 according to the output method and output conditions.

  The NAND FLASH 17 stores a program executed by the ASIC 16, and the NVRAM 18 stores information such as the model number of the image forming apparatus and the number of printed pages.

  The controller board 20 has a mounting portion 23 for mounting an option board, and the option board 30 is mounted on the mounting portion 23 by a user or the like. The mounting unit 23 has, for example, a PCI bus that connects the CPUs 15 and 33.

  Similarly, the option board 30 is also controlled by the CPU 33, and a ROM 31, a RAM 34, and a NANDFLASH 32 are connected to the CPU 33. The option board 30 can perform image processing similar to that of the CPU 15 of the controller board 20 and image processing that is difficult with the CPU 33 of the controller board 20, and the addition of the option board 30 makes it possible to add functions and improve processing performance. . Image processing that can be performed by the option board 30 is notified to the controller board 20 at the time of mounting.

  FIG. 3 is an example of a functional block diagram of the image forming apparatus 100 of the present embodiment. First, the controller board 20 includes an application 51, a UI unit 52, an image processing determination unit 53, and a frequency determination unit 54. The image processing determining unit 53 includes an image processing unit (hereinafter, when distinguished, image processing units 1 to n) 55.

  First, the UI unit 52 displays a UI for each application on the LCD or the like of the operation unit 41 according to the application 51 selected by the user. The application 51 receives input, processing, and output conditions used by the functions of the image forming apparatus 100 such as a scanner application, a copy application, and a transmission application, and designation of image data. As a result, the output method and output conditions are determined.

  The image processing determination unit 53 determines the content of image processing according to the output method and output conditions. Although there are various contents of image processing, image processing is performed by calling the image processing units 1 to n according to the image processing and executing them in order.

  When the option board 30 is connected, the image processing determination unit 53 distributes the image processing performed by the controller board 20 and the image processing performed by the option board 30 based on the image processing units 1 to n. This distribution causes the three processing modes (i) to (iii) described above. The image processing determination unit 53 has a processing determination table 56 in which combinations of the image processing units 1 to n and the board that performs the image processing are determined in advance.

  FIG. 4A is a diagram illustrating an example of the processing determination table 56. In the processing determination table 56, identification information of a board that performs image processing is registered in association with the image processing units 1 to n. For example, JPEG encoding performed by the image processing unit 1 can be performed by the option board 30, PDF conversion performed by the image processing unit 2 can be performed by the controller board 20, and OCR processing performed by the image processing unit 3 can be performed. The controller board 20 and the option board 30 are registered in parallel. The image processing determination unit 53 notifies the frequency determination unit 54 of the processing modes (i) to (iii) determined based on the processing determination table 56.

Returning to FIG. 3, the frequency determination unit 54 determines the frequency of the CPU 15 of the controller board 20 and the frequency of the CPU 33 of the option board 30 based on the processing mode.
FIG. 4B is a diagram illustrating an example of the frequency determination table 58. The frequencies of the controller board 20 and the option board 30 are registered in accordance with the processing modes (i) to (iii).
(i) In the case of parallel processing, the frequency of the CPU 15 of the controller board 20 is c2, and the frequency of the CPU 33 of the option board 30 is c11.
(ii) When only the controller board performs processing, the frequency of the CPU 15 of the controller board 20 is c1, and the frequency of the CPU 33 of the option board 30 is c12.
(iii) When only the option board processes, the frequency of the CPU 15 of the controller board 20 is c3, and the frequency of the CPU 33 of the option board 30 is c11.
Here, c1>c2> c3, c11> c12.

  In the case of (i), since the controller board 20 and the option board 30 process together, the frequency of the option board 30 is maximized and the frequency of the controller board 20 is set to a medium level, while the option board 30 is processed at high speed. Designed not to exceed the rated power. The frequency c2 of the controller board 20 in the case of (i) is the maximum frequency in a range not exceeding the power excluding the power consumption when the option board 30 operates at the frequency c11 (Max value) from the rated power of the PSU 40. .

In the case of (ii), since only the controller board 20 performs processing, the processing speed can be increased without exceeding the rated power by maximizing the frequency of the controller board 20.
In the case of (iii), since only the option board 30 performs processing, power consumption can be suppressed by minimizing the frequency of the controller board 20 and maximizing the frequency of the option board 30.

  The frequency c1 is a Max value of the frequency of the CPU 15 of the controller board 20 and is a frequency at the time of activation. c3 is the Min value of the frequency of the CPU 15 of the controller board 20. Further, c11 is a maximum value of the frequency of the CPU 33 of the option board 30. c12 is the Min value of the frequency of the CPU 33 of the option board 30 and is the frequency at the time of activation.

  The frequency determining unit 54 sets the frequency thus determined in the PLL 61 of the controller board 20. On the controller board side, CLK supplies a clock signal having a predetermined frequency to the PLL 61. Since the PLL 61 divides the clock signal based on the set frequency, the frequency determined by the PLL 61 can be supplied to the CPU 15 of the controller board 20.

  In addition, the frequency determination unit 54 sets the determined frequency in the NANDFLASH 32 on the option board side. The option board 30 acquires the notification from the controller board 20 by interruption or the like and activates the frequency setting unit 64. The frequency setting unit 64 sets the frequency stored in the NAND FLASH 32 in the PLL 66. Since the PLL 66 divides the clock signal based on the set frequency, the frequency determined by the frequency determination unit 54 can be supplied to the CPU 33 of the option board 30.

  Note that the frequency determination unit 54 sets the minimum frequency c12 to the NANDFLASH 32 of the option board 30 at the time of startup when the power is turned on. Accordingly, when the option board 30 is activated, the option board 30 is activated at the minimum frequency, so that power consumption can be suppressed.

  The option detection unit 57 determines whether the option board 30 is connected by utilizing the fact that the logic of a predetermined I / O 59 of the ASIC 16 is inverted when the option board 30 is connected to the controller board 20.

[Operation procedure]
<At startup>
FIG. 5 is an example of a flowchart illustrating an operation procedure when the image forming apparatus 100 is activated. The procedure in FIG. 5 starts when the image forming apparatus 100 is turned on. When a preset time has elapsed since the power-on, the CPU 15 of the controller board 20 is subjected to energy saving control, for example, by the ASIC 16, and may have a low frequency for standby. However, immediately after the power is turned on, the CPU 15 operates at the initial frequency c1 set in the PLL 61.

  When the image forming apparatus 100 is activated, for example, a reset signal to the CPU 15 is negated and the CPU 15 is activated by reset. The CPU 15 executes an IPL (Initial Program Loader) to cause the CPU 15 to execute a program for initial processing in which the IPL is predetermined. In this embodiment, an option detection unit 57 and a frequency determination unit 54 are included in one of the initial processes.

  The option detection unit 57 monitors the state of a predetermined I / O 59 of the ASIC 16 and determines whether or not the option board 30 is mounted (S10). The frequency determination unit 54 determines the frequency to be set in the option board 30 according to the determination result of the option detection unit 57.

  When the option board 30 is not connected (No in S10), the frequency determination unit 54 does not need to determine the frequency of the option board 30. In this case, the frequency of the CPU 15 of the controller board 20 remains the frequency c1 at the time of activation, and may decrease as time elapses.

  When the option board 30 is connected (Yes in S10), the frequency determining unit 54 writes the minimum frequency c12 to the NANDFLASH 32 of the option board 30 (S20).

FIG. 6 is an example of a flowchart for explaining the frequency setting procedure of the CPU 33 of the option board 30 when the option board 30 is activated. There are two cases of activation of the option board 30 as follows.
(A) Start by turning on the power as in the controller board 20 (b) Start by control from the controller board 20 Among these, (a) is the same as the case of dynamically changing the frequency of the option board 30, so FIG. I will explain. FIG. 6 shows the startup procedure in the case of (b), and it is assumed that the frequency c12 of the option board 32 has already been stored in the NANDFLASH 32.

  The CPU 33 of the option board 30 is activated at the initial setting frequency set in the PLL 66 (S110). This frequency is the maximum frequency (c11 in the case of an option board).

  The option board 30 CPU 33 executes the IPL to cause the CPU 33 to execute a program for initial processing in which the IPL is predetermined. In this embodiment, one of the initial processes includes the frequency setting unit 64 (S120).

  The frequency setting unit 64 sets the frequency stored in the NANDFLASH 32 in the PLL 66 (S130). As a result, the PLL 66 changes the frequency division ratio of the clock signal output from the CLK and outputs a clock signal having a set frequency. As described above, since this frequency is the lowest frequency c12 in the specification of the CPU 33 of the option board 30, the power consumption consumed by the option board 30 can be reduced.

<During image formation>
FIG. 7 is an example of a flowchart illustrating a frequency setting procedure when the image forming apparatus 100 performs image processing.

  When the user operates the operation unit 41 to set input, processing, and output conditions, the image processing determination unit 53 determines image processing. The image processing determination unit 53 refers to the processing determination table 56 and sets a board for executing image processing for each image processing as the controller board 20, the option board 30, or both the controller board 20 and the option board 30, (S210).

  The frequency determination unit 54 determines the frequencies of the controller board 20 and the option board 30 with reference to the frequency determination table 58.

(i) The controller board 20 and the option board 30 perform parallel processing. In this case, the frequency determination unit 54 sets the frequency of the CPU 15 of the controller board 20 to c2, and sets the frequency of the CPU 33 of the option board 30 to c11 (S220). ). The frequency determination unit 54 sets c2 in the PLL 61 of the controller board 20 and stores c11 in the NANDFLASH 32 of the option board 30. Therefore, the frequency of the CPU 15 of the controller board 20 is reduced, and the frequency of the CPU 33 of the option board 30 is increased.

Controller board c1 → c2
Option board c12 → c11
Thereafter, the controller board 20 and the option board 30 each execute image processing (S230).

(ii) Only the controller board performs processing In this case, the frequency determination unit 54 sets the frequency of the CPU 15 of the controller board 20 to c1, and sets the frequency of the CPU 33 of the option board 30 to c12. Therefore, the frequency determination unit 54 does nothing, and neither the CPU 15 of the controller board 20 nor the CPU 33 of the option board 30 changes the frequency.

Controller board c1 → c1
Option board c12 → c12
The controller board 20 executes image processing (S240).

(iii) Only the option board performs processing In this case, the frequency determination unit 54 sets the frequency of the CPU 15 of the controller board 20 to c3, and sets the frequency of the CPU 33 of the option board 30 to c11 (S250). The frequency determination unit 54 sets c3 in the PLL 61 of the controller board 20 and stores c11 in the NANDFLASH 32 of the option board 30. Therefore, the frequency of the CPU 15 of the controller board 20 is reduced, and the frequency of the CPU 33 of the option board 30 is increased.

Controller board c1 → c3
Option board c12 → c11
Thereafter, the option board 30 executes image processing (S260).

<Change frequency of option board>
FIG. 8 is an example of a flowchart showing a procedure for changing the option board 30 to the set frequency.

  The CPU 33 of the option board 30 detects that a new frequency has been set by, for example, an interrupt from the controller board 20 (S310). As a result, the CPU 33 of the option board 30 activates the frequency setting unit 64.

  The frequency setting unit 64 reads the set frequency from the NAND FLASH 32 (S320). Then, the PLL 66 is set (S330). Thus, even if the controller board 20 determines the frequency, the frequency can be changed under the control of the option board 30 by the option board 30 performing the actual setting.

  When the processing of the frequency setting unit 64 is completed, the controller board 20 returns to the process before the interruption, so that the image processing program can be executed to execute the image processing. The image data to be processed is stored in the RAM 34 of the option board 30 by the controller board 20. When the image processing is completed, the image processing unit 65 of the option board 30 moves the image data to the RAM 13 of the controller board 20.

<After image processing>
FIG. 9 is an example of a flowchart illustrating a frequency setting procedure after the image processing is completed. When the frequency is higher than the Min value after the image processing is finished, the power consumption can be reduced by lowering the frequency. For this reason, the controller board 20 and the option board 30 quickly set the frequency to the Min value.

  The frequency determination unit 54 monitors whether or not a predetermined time has elapsed since the image processing was completed (S410). For example, the image processing determination unit 53 detects that the image processing has been completed.

And when a predetermined time has passed,
The controller board frequency is set to c3 (Min value). The option board frequency is set to c12 (Min value) (S420).

  By doing so, the frequencies of the controller board 20 and the option board 30 can be continuously minimized, so that the power consumption can be reduced. If the frequency of the controller board 20 is set to c3 (Min value), for example, if a time lag occurs before starting image processing, the frequency of the CPU 15 of the controller board 20 is higher than c3. It is also possible to set the frequency (c1 or c2 etc.).

[High-speed processing and power consumption]
10A shows an example of the relationship between the processing mode and the power consumption. FIG. 10B shows the processing time shortened when the image forming apparatus 100 performs the frequency control in (i) parallel processing. It is a figure explaining an example.

  In FIG. 10A, processing A is, for example, OCR processing, and the processing mode is (i). The process B is, for example, PDF conversion and the processing mode is (ii). The process C is, for example, JPEG encoding, and the processing mode is (iii).

  First, it is assumed that the rated power of the controller board 20 of the image forming apparatus 100 is 12 W, the power consumption at c1 of the controller board 20 is 10 W, and the power consumption at the option board 30 is 3 W. For this reason, if the controller board 20 and the option board 30 operate at c1 and c11 without controlling the frequency, the total becomes 13 W, which exceeds the rated power of 12 W.

  Therefore, in this embodiment, in the process A (OCR), the frequency of the CPU 15 of the controller board 20 is lowered to 7 W. Thereby, even if the frequency of CPU33 of the option board 30 is raised to c11 (Max value), it does not exceed rated power 12W. Accordingly, when the image forming apparatus 100 performs parallel processing, the frequency of the CPU 15 of the controller board 20 is lowered in this way, but the image processing performed by the controller board 20 is not significantly delayed by not reducing the frequency to the Min value. Can be done.

  In process B (PDF conversion), the frequency of the CPU 15 of the controller board 20 is not changed, but since the frequency of the CPU 33 of the option board 30 is c12 (Min value), the total power consumption is 10 W, and the rated power 12 W is obtained. It does not exceed.

  In process C (JPEG encoding), even if the frequency of the CPU 15 of the controller board 20 is lowered to c3 (Min value) and the frequency of the CPU 33 of the option board 30 is raised to c11 (Max value), the total power consumption becomes 4 W. The power consumption can be made sufficiently lower than the rated power of 12W.

  As shown in FIG. 10B, if the option board 30 is not installed, the CPU 15 of the controller board 20 sequentially performs image processing by itself, so that the processing time of the image processing is T1 + T2.

  When the option board 30 is attached, the option board 30 can process a process corresponding to the processing time of T2. In the case of parallel processing, the frequency of the CPU 15 of the controller board 20 changes from c1 to c2 (decreases), so the processing time T1 is T1 ′ (> T1). Since the frequency of the CPU 33 of the option board 30 changes (increases) from c12 to c11, the processing time T2 becomes T2 ′ (<T2). Here, assuming that c1 <c11, the processing time T2 ′ is shorter than T2.

  Even if the controller board 20 and the option board 30 perform processing corresponding to the processing times T1 and T2 in sequential processing, T1 + T2> T1 ′ + T2 ′. Therefore, the total time is slightly faster.

  When the option board 30 is installed, the controller board 20 and the option board 30 are originally processed in parallel, so the total processing time is the longer of the processing times T1 ′ and T2 ′. In FIG. 10B, the processing times T1 ′ and T2 ′ are made equal, but the processing time T1 processing times T1 ′ and T2 ′ differ depending on the absence of image processing. Therefore, even if the CPU 15 of the controller board 20 is reduced in frequency and processed in parallel (even if the processing time T1 ′ is longer than T1), the total processing time can be greatly reduced. In this case, since the power consumption is only 10 W, there is a sufficient margin for the rated power. Therefore, since the option board 30 is mounted, the rated power of the image forming apparatus 100 is not estimated too much, and even when the option board 30 is mounted, the range of the rated power is within the range of the rated power, compared to the case where only the controller board 20 processes. It can be processed.

  Further, when only the controller board 20 performs processing as in processing B, the power consumption of the option board 30 is wasted. However, since the frequency of the CPU 33 of the option board 30 is a Min value, the amount of increase can be minimized.

  Further, when only the option board 30 performs processing as in processing C, the frequency of the CPU 15 of the controller board 20 is set to the Min value, so that power consumption can be reduced.

  As described above, the image forming apparatus 100 of the present embodiment increases the rated power by controlling the frequency of each CPU according to the board that performs image processing when the option board 30 is mounted. Image processing can be executed efficiently.

  In this embodiment, an image forming apparatus 100 that can dynamically change the frequency of the CPU 15 of the controller board 20 will be described.

  FIG. 11 shows an example of a functional block diagram of the image forming apparatus 100 of the present embodiment. In FIG. 11, the description of the same part as in FIG. 3 is omitted. The image forming apparatus 100 according to the present exemplary embodiment includes a power consumption map 63 instead of the frequency determination table 58.

  FIG. 12 is an example of a diagram for schematically explaining the power consumption map 63. In the power consumption map 63, the frequency and the power consumption are registered in association with the CPUs 15 and 33 of the controller board 20 and the option board 30, respectively. Since the controller board 20 does not know what type of option board 30 is mounted, the controller board 20 stores the power consumption map 63 of its own device in advance, and the power consumption map 63 of the option board 30 is stored from the option board 30. read out.

  The controller board 20 has a rated power storage unit 60 in which rated power is stored. The frequency determination unit 54 can read the rated power from the rated power storage unit 60.

Hereinafter, two frequency determination methods by the frequency determination unit 54 will be described.
(1) Fix the frequency of the option board to the Max value The frequency determination unit 54 refers to the power consumption map 63 and determines the frequencies of the CPU 33 of the controller board 20 and the option board 30 within a range not exceeding the rated power. To do. Of the processing modes (i) to (iii) of Example 1, (ii) and (iii) are the same as in Example 1.

(i) The controller board 20 and the option board 30 perform parallel processing The frequency determination unit 54 reads the power consumption (for example, 3 W) associated with the Max value of the CPU 33 of the option board 30 from the power consumption map 63.

  The read power consumption is subtracted from the rated power (for example, 12W-3W = 9W).

  The frequency of the CPU 15 of the controller board 20 associated with the power consumption obtained by subtraction is read from the power consumption map 63 (for example, the frequency c2 of the CPU 15 of the controller board 20 associated with 9 W is read).

  Thus, by determining the frequencies of the controller board 20 and the option board 30, the processing time can be minimized within the rated power range.

  The frequency of the CPU 15 of the controller board 20 may be determined as the Max value, and the maximum frequency of the CPU 33 of the option board 30 within the rated power range may be determined.

(ii) Only the controller board 20 performs image processing The frequency determination unit 54 sets the frequency of the CPU 15 of the controller board 20 to the Max value, and sets the frequency of the CPU 33 of the option board 30 to the Min value (that is, no change). .

(iii) Only the option board performs image processing The frequency determination unit 54 sets the frequency of the CPU 15 of the controller board 20 to the Min value, and sets the frequency of the CPU 33 of the option board 30 to the Max value.

(2) Switching the frequency of the option board according to the rated power and the Max value If the power consumption at the Max value of the frequency of the CPU 33 of the option board 30 is large, the frequency of the controller board 20 may be kept low. For this reason, it is effective to make the frequency of the CPU 33 of the option board 30 variable according to the rated power and the power consumption at the Max value of the option board 30.

The frequency determination unit 54 makes the frequency of the CPU 33 of the option board 30 variable according to the difference between the rated power and the power consumption at the Max value of the CPU 33 of the option board 30 as follows. The frequency of the CPU 15 of the controller board 20 is determined within a range not exceeding the rated power.
“Power consumption when rated power−Max value” is greater than or equal to a predetermined value: Max value “Power consumption when rated power−Max value” is less than a predetermined value: Max value × 0.8
If the value is less than the predetermined value, the coefficient may be changed so that the frequency of the CPU 33 is reduced according to the value. If there is not enough room for the rated power, the frequency of the option board 30 is lowered below the Max value. Even when the power consumption of 30 is large or the rated power is not sufficient, it is possible to prevent the processing of the controller board 20 from being delayed or the rated power from being insufficient.

  In the first and second embodiments, the frequency determination unit 54 determines the frequencies of the CPU 33 of the controller board 20 and the option board 30. In this embodiment, the image forming apparatus 100 that allows the user to determine the frequency will be described.

  For example, when the user installs the option board 30 and turns on the power of the image forming apparatus 100, or the user operates the operation unit 41, the frequencies of the controller board 20 and the CPU 33 of the option board 30 are set. A screen is displayed.

  FIG. 13 is a diagram illustrating an example of a frequency setting screen. FIG. 13 shows a message 201 “Please set the frequency of the controller board and the option board 30”, a frequency range 202 that can be set on the controller board 20, a frequency range 203 that can be set on the option board 30, and the CPU 15 of the controller board 20. A frequency setting column 204 for the CPU 33 and a frequency setting column 205 for the CPU 33 of the option board 30 are displayed.

  When the user sets the frequency of one of the boards, the frequency determining unit 54 determines the maximum frequency that can be set in the other board from the power consumption map 63 within the range of the rated power and displays it on the frequency setting screen.

  Therefore, the user can set the frequency with priority between the controller board 20 and the option board 30, and can set the frequency of the other board within the range of the rated power.

11, 16 ASIC
13,34 RAM
14,31 ROM
15,33 CPU
20 Controller board 30 Option board 40 PFU
DESCRIPTION OF SYMBOLS 41 Operation part 43 Scanner part 44 Plotter part 53 Image processing determination part 54 Frequency determination part 56 Processing determination table 57 Option detection part 58 Frequency determination table 63 Power consumption map 100 Image forming apparatus

JP 2007-249808 A

Claims (8)

Image data acquisition means for acquiring image data;
Operation accepting means for accepting image processing performed on the image data;
Output means for outputting the image data subjected to image processing;
A first central processing unit for performing image processing;
An interface capable of mounting a second central processing unit for performing image processing;
A mounting detection means for detecting whether or not the second central processing unit is mounted on the interface;
A processing determination table in which one of the first central processing unit, the second central processing unit, or the first and second central processing units in parallel is registered in association with image processing. When,
Corresponding to the processing mode, a frequency determination table in which the frequencies of the first central processing unit and the second central processing unit are registered, and
Processing mode determining means for determining the processing mode by referring to the processing determination table based on image processing;
Referring to the frequency determination table based on the processing mode, and a frequency determining means for determining the frequencies of the first and second central processing units;
First frequency control means for controlling the frequency of the first central processing unit;
Second frequency control means for controlling the frequency of the second central processing unit;
An image forming apparatus. When the processing mode determining means determines that the first and second central processing units execute processing in parallel,
The frequency determining means determines the frequency of the first central processing unit to a frequency between the minimum value and the maximum value of the frequency of the first central processing unit, and sets the frequency of the second central processing unit to the second central processing unit. Determine the maximum frequency of the processing equipment,
The image forming apparatus according to claim 1. When the frequency of the first central processing unit is the maximum value and the frequency of the second central processing unit is the maximum value, the power consumption exceeds the rated power,
When the frequency of the first central processing unit is a frequency between the minimum value and the maximum value, and the frequency of the second central processing unit is the maximum value, the power consumption is less than the rated power.
The image forming apparatus according to claim 2. When the processing mode determining means determines that the first central processing unit alone performs processing, the frequency determining means determines the frequency of the second central processing unit to the minimum value,
When the processing mode determining means determines that the second central processing unit alone performs processing, the frequency determining means determines the frequency of the first central processing unit to the minimum value.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. Rated power storage means for storing the rated power;
A power consumption calculation map in which power consumption is associated with the frequency of the first central processing unit, and power consumption is associated with the frequency of the second central processing unit, and
The frequency determining means determines the frequencies of the first and second central processing units within a range where the sum of the power consumption of the first central processing unit and the power consumption of the second central processing unit does not exceed the rated power. ,
The image forming apparatus according to claim 1. The frequency determining means obtains a difference in power consumption when the frequency of the second central processing unit is maximum with respect to the rated power. When the difference is a predetermined value or more, the frequency determining means Determine the maximum frequency,
If the difference is less than a predetermined value, the frequency determining means determines the frequency of the second central processing unit to a value smaller than the maximum,
The image forming apparatus according to claim 5. Having frequency receiving means for receiving the frequency settings of the first central processing unit and the second central processing unit;
The image forming apparatus according to claim 1. Image data acquisition means for acquiring image data;
Operation accepting means for accepting image processing performed on the image data;
Output means for outputting the image data subjected to image processing;
A first central processing unit for performing image processing;
An interface capable of mounting a second central processing unit for performing image processing, and a frequency control method for the image forming apparatus,
A step of detecting whether or not the second central processing unit is mounted by a mounting detection means;
Based on the image processing, the processing mode determining means is associated with the image processing, either the first central processing unit alone, the second central processing unit alone, or the first and second central processing units in parallel Determining the processing mode with reference to the processing determination table in which the processing mode is registered;
Based on the processing mode, the frequency determination means refers to the frequency determination table in which the frequencies of the first central processing unit and the second central processing unit are registered in association with the processing mode, and the first and second Determining the frequency of the central processing unit;
A first frequency control means for controlling a frequency of the first central processing unit;
A second frequency control means for controlling the frequency of the second central processing unit;
A frequency control method comprising:

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