JP2014178627A - Image display controller, image display device and image display control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce occupancy of the memory bus bandwidth of a shared memory by an image display control device with a simple and inexpensive configuration when an image is displayed on an image display device.SOLUTION: An image display control device includes a basic data storage part for storing basic data: compares a pixel value of image data for the (N+1)th frame being read out from a shared memory with these of the basic data for each pixel at the time of refreshment from the Nth frame to the (N+1)th frame when the (N+1)th frame is the same as the (N+2)th frame; reads out pixels having different pixel values from the shared memory in the compared result when the (N+2)th frame is displayed on an image display part; reads out the same pixels from the basic data storage part; and uses them as image data for displaying the (N+2)th frame on the image display part.

Description

  The present invention relates to an image display control device, an image display device, and an image display control method, and more particularly to image display control in an image display device.

  In recent years, connected to an information processing device such as a PC (Personal Computer) or a DVD (Digital Versatile Disc) player, an image display device for displaying an image based on image data input from the information processing device, An image display device for receiving radio waves of television broadcasting and displaying images and sounds as a television receiver is an indispensable device for offices and homes.

As such an image display device, a cathode ray tube display, a liquid crystal display, an organic EL (Electro Luminescence) display, an LED (Light Emitting Diode) display, and the like are known. In recent years, it has been connected to an information processing device such as a PC or a DVD player. An image display device such as a projector that displays an image on a projection surface such as a wall or a screen by projecting the image as light based on the image data input from those information processing devices is also used in offices and homes. Has become an indispensable device.

  These image display devices perform a so-called refresh operation in which a screen is constantly rewritten while an image is displayed. By such an operation, the image display device can display a still image and further display a moving image. The number of refreshes performed per second by such an image display device, that is, the number of times the screen is rewritten per second is referred to as a refresh rate, and the image display device displays a moving image more smoothly as the refresh rate is higher. In addition, the screen resolution and the number of simultaneous colors can be increased, and flicker can be reduced.

  Such refresh is performed by control of an image display control device that performs control related to image display in the image display device. At this time, image data for displaying an image on the image display device is temporarily stored in a frame buffer in order to synchronize with the timing of image display, and the image display control device performs image display on the image display device. The process of reading the image data from the frame buffer at the timing and displaying the image on the image display device based on the read image data is performed for each refresh.

  The frame buffer as described above may be realized by a shared memory that is shared and used by the entire system (see, for example, Patent Document 1) and may be realized by a dedicated memory that is used only as a frame buffer. is there.

  However, in the former case, there is a problem in that much of the memory bus bandwidth of the shared memory is occupied by the image data reading by the image display control device. This is because, as described above, the image display device needs to constantly refresh while displaying an image, and the image display control device must access the shared memory every time the image is displayed. Therefore, in the former case, there is no room for another bus master to access the memory.

  On the other hand, in the latter case, the image display control apparatus reads the image data from the frame buffer dedicated memory instead of the shared memory. Therefore, the above problem does not occur. Therefore, a complicated circuit, an increase in circuit scale, an increase in power consumption, and an increase in cost are problems.

  The present invention has been made to solve such a problem. When an image is displayed on the image display device, the image display control device occupies the memory bus bandwidth of the shared memory with a simple and inexpensive configuration. The purpose is to reduce.

  In order to solve the above-described problem, an image display control apparatus that updates display of an image display unit every predetermined period, and pixel information of each pixel constituting an image to be displayed on the image display unit in a certain period. A pixel information acquisition unit that is acquired from an external storage medium, an update processing unit that updates the display of the image display unit based on the acquired pixel information, and a reference that indicates a reference density in the display of the image display unit A reference pixel information storage unit storing pixel information and a comparison result between the acquired pixel information and the reference pixel information are stored in a storage medium for each pixel constituting an image for displaying on the image display unit. A pixel of a pixel different from the reference pixel information based on the comparison result when updating the display of the comparison processing unit that performs comparison processing and the display of the image display unit for the next period of the certain period A pixel information acquisition control unit that operates the pixel information acquisition unit so as to acquire only information from the external storage medium, and pixel information of the pixel different from the reference pixel information acquired based on the comparison result and the reference A pixel information combining unit that combines the pixel information and generates a combined image for display on the image display unit, and the update processing unit is based on the combined image for the next period of the certain period. The display of the image display unit is updated.

  Another aspect of the present invention is an image display device including the image display control device.

According to still another aspect of the present invention, there is provided an image display control method for updating display of an image display unit every predetermined period, and each pixel constituting an image to be displayed on the image display unit in a certain period. An image for acquiring pixel information from an external storage medium, and causing the image display unit to display a comparison result between the acquired pixel information and reference pixel information indicating a reference density in display of the image display unit A pixel that is different from the reference pixel information based on the comparison result when updating the display of the image display unit for the next period of the certain period. The pixel information acquisition unit is operated so that only the pixel information of the pixel is acquired from the external storage medium, and the pixel information of the pixel different from the reference pixel information acquired based on the comparison result and the pixel information Generating a composite image to be displayed on the image display unit by combining the semi-pixel information,
The display of the image display unit for the next period of the certain period is updated based on the composite image.

  According to the present invention, when displaying an image on the image display device, it is possible to reduce the occupation of the memory bus band of the shared memory by the image display control device with a simple and inexpensive configuration.

It is a block diagram which shows typically the hardware constitutions of the image display apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the data structure of the image data which concerns on embodiment of this invention. It is a figure which shows an example of the data structure of the basic data which the basic data storage part which concerns on embodiment of this invention stores. It is a figure which shows an example of the data structure of the basic data which the basic data storage part which concerns on embodiment of this invention stores. It is a figure which shows an example of the data structure of the basic data which the basic data storage part which concerns on embodiment of this invention stores. It is a figure which shows an example of the data structure of the basic data which the basic data storage part which concerns on embodiment of this invention stores. It is a flowchart explaining the procedure of the comparison determination process by the comparison determination process part which concerns on embodiment of this invention. It is a flowchart explaining the procedure of the image data read-out process by the DMA control part which concerns on embodiment of this invention. It is a flowchart explaining the procedure of the display data generation process by the display data generation part which concerns on embodiment of this invention. It is a block diagram which shows typically the hardware constitutions of the image display apparatus which concerns on other embodiment of this invention. It is a figure which shows an example of the several area | region which the comparison determination process part which concerns on other embodiment of this invention sets to the image data input from a DMA control part. It is a figure which shows an example of the final determination result which the determination result storage part which concerns on other embodiment of this invention stores. It is a figure which shows an example of the final determination result which the determination result storage part which concerns on other embodiment of this invention stores. It is a flowchart explaining the procedure of the comparison determination process by the comparison determination process part which concerns on other embodiment of this invention. It is a figure which shows an example of the several area | region which the comparison determination process part which concerns on further another embodiment of this invention sets in the horizontal direction of the image data input from a DMA control part. It is a figure which shows an example of the several area | region which the comparison determination process part which concerns on further another embodiment of this invention sets to the orthogonal | vertical direction of the image data input from a DMA control part. It is a figure which shows an example of the determination result which the determination result temporary storage part which concerns on further another embodiment of this invention stores. It is a figure which shows an example of the determination result which the determination result temporary storage part which concerns on further another embodiment of this invention stores. It is a figure which shows an example of the final determination result which the determination result storage part which concerns on further another embodiment of this invention stores. It is a figure which shows an example of the determination result which the determination result temporary storage part which concerns on further another embodiment of this invention stores. It is a figure which shows an example of the determination result which the determination result temporary storage part which concerns on further another embodiment of this invention stores. It is a figure which shows an example of the final determination result which the determination result storage part which concerns on further another embodiment of this invention stores. It is a flowchart explaining the procedure of the comparison determination process with respect to the horizontal direction by the comparison determination process part which concerns on further another embodiment of this invention. It is a flowchart explaining the procedure of the determination result integration process by the comparison determination process part which concerns on further another 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 display device including a cathode ray tube display, a liquid crystal display, an organic EL (Electro Luminescence) display, an LED (Light Emitting Diode) display, and the like as an image display unit will be described as an example.

  Such an image display apparatus performs a so-called refresh operation in which a screen is constantly rewritten while an image is displayed. By such an operation, the image display apparatus according to the present embodiment can display a still image and further display a moving image. The number of refreshes performed per second by such an image display device, that is, the number of times the screen is rewritten per second is referred to as a refresh rate, and the image display device displays a moving image more smoothly as the refresh rate is higher. In addition, the screen resolution and the number of simultaneous colors can be increased, and flicker can be reduced. In the following, it is assumed that the image displayed on the image display unit is the Nth frame (N is a natural number) and represents the order of display according to the magnitude of N.

  Such refresh is performed by control of an image display control device that performs control related to image display in the image display device. At this time, the image data for displaying the image on the image display unit is temporarily stored in the frame buffer in order to synchronize with the image display timing, and the image display control device estimates the image display timing. The process of reading the image data from the frame memory and displaying an image on the image display unit based on the read image data is performed for each refresh. In the present embodiment, the frame buffer is realized by an area allocated to a part of a shared memory that is shared and used in the entire system.

  In addition, the image display control apparatus according to the present embodiment includes a basic data storage unit that stores basic basic data set in advance, and the (N + 1) th frame and the (N + 2) frame are the same. The pixel values of the image data for the (N + 1) th frame being read from the shared memory and the basic data are compared for each pixel when refreshing from the Nth frame to the (N + 1) th frame. Has been.

  Then, when the image display control apparatus according to the present embodiment displays the (N + 2) th frame on the image display unit, pixels having different pixel values in the comparison result are read from the shared memory, and the same pixels are read. It is configured to read out from the basic data storage unit and use them as image data for displaying the (N + 2) th frame on the image display unit.

  In this case, when the (N + 1) th frame and the (N + 2) th frame are the same, the image display control apparatus performs an image for the (N + 2) th frame when refreshing from the (N + 1) th frame to the (N + 2) th frame. There is no need to read all of the data from the shared memory. In other words, when the (N + 1) th frame and the (N + 2) frame are the same, the image display control apparatus according to the present embodiment performs basic data and pixel processing when refreshing from the (N + 1) th frame to the (N + 2) frame. Only the pixels with different values need only be read from the shared memory 200.

  Therefore, according to the image display apparatus according to the present embodiment, it is possible to reduce the number of times of access to the shared memory by reading the image data in the image display control apparatus in association with the refresh, and it is dedicated for use only as a frame buffer. There is no need to provide memory.

  Thereby, the image display apparatus according to the present embodiment can reduce the occupation of the memory bus bandwidth of the shared memory by the image display control apparatus with a simple and inexpensive configuration when displaying an image. Details will be described below.

  First, the hardware configuration of the image display apparatus 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram schematically showing a hardware configuration of the image display apparatus 1 according to the present embodiment. As illustrated in FIG. 1, the image display device 1 according to the present embodiment includes a processor 100, a shared memory 200, an image display control device 300, and an image display unit 400.

  The processor 100 is a calculation unit such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), and controls the entire operation of the image display apparatus 1. The shared memory 200 is a nonvolatile storage medium that can read and write information at high speed, and is realized by a main storage device such as a RAM (Random Access Memory). The shared memory 200 is used as a work area for temporarily storing data to be processed by the processor 100 in addition to loading programs for the processor 100 to realize various functions, and the entire image display device 1. Shared by and used. That is, in the present embodiment, the shared memory 200 functions as an external storage memory.

  The shared memory 200 also includes a frame buffer 210. The frame buffer 210 temporarily stores image data for causing the image display device 1 to display an image on the image display unit 400 to synchronize with the image display timing. To store.

  The image display control device 300 performs control related to image display of the image display unit 400, and includes a main control unit 310, a DMA (Direct Memory Access) control unit 320, a comparison determination processing unit 330, a basic data storage unit 340, and a determination result storage unit. 350, a display data generation unit 360, and a display control signal generation unit 370.

  The main control unit 310 plays a role of controlling each unit included in the image display control device 300 according to the control of the processor 100, and gives a command to each unit of the image display control device 300.

  The DMA control unit 320 is a dedicated integrated circuit that controls communication in DMA transfer in which data transfer is performed without using a processor. The DMA control unit 320 reads the refreshed image data stored in the frame buffer 210 and inputs it to the display data generation unit 360 for each refresh.

  However, when the DMA control unit 320 receives a notification from the main control unit 310 that the (N + 1) th frame and the (N + 2) th frame are the same, the DMA control unit 320 changes from the Nth frame to the (N + 1) th frame. At the time of refreshing, the image data after refreshing (for the (N + 1) th frame) stored in the frame buffer 210 is read out and input to the comparison determination processing unit 330 in addition to the display data generation unit 360. That is, in the present embodiment, the DMA control unit 320 functions as a pixel information acquisition unit.

  As will be described later, the DMA control unit 320 according to the present embodiment notifies the determination result from the determination result storage unit 350 when the images displayed on the image display unit 400 are the same before and after the refresh. By referring to the determination result, it is not necessary to read out all of the image data for displaying the refreshed image on the image display unit from the frame buffer 210, and the frame buffer is used only for pixels having pixel values different from the basic data. It is only necessary to read from 210. In the present embodiment, such a function provided by the DMA control unit 320 is one of the gist.

  The comparison determination processing unit 330 receives a notification from the main control unit 310 that the (N + 1) th frame and the (N + 2) th frame are the same during the refresh from the Nth frame to the (N + 1) th frame. In this case, the pixel values of the basic data stored in the basic data storage unit 340 and the image data for the (N + 1) th frame input from the DMA control unit 320 are compared for each pixel as pixel information. The determination result is stored for each pixel in the determination result storage unit 350.

  That is, the comparison determination processing unit 330 receives the basic data stored in the basic data storage unit 340 and the (N + 1) th input from the DMA control unit 320 when refreshing from the Nth frame to the (N + 1) th frame. ) When it is determined that the pixel values of the image data for the frame are the same, “0” is determined as the determination result for the pixel. Is stored in the determination result storage unit 350. Hereinafter, such processing by the comparison determination processing unit 330 is referred to as comparison determination processing. That is, in the present embodiment, the comparison determination processing unit 330 functions as a comparison processing unit.

  The basic data storage unit 340 stores basic data to be compared with image data by the comparison determination processing unit 330 in advance. The basic data includes, for example, data related to a predetermined portion such as a frame and background common to all image data. That is, in this embodiment, basic data is used as reference pixel information, and the basic data storage unit 340 functions as a reference pixel information storage unit.

  The determination result storage unit 350 stores the determination result by the comparison determination processing unit 330. Further, the determination result storage unit 350 displays the stored determination result before the DMA control unit 320 reads out the image data for causing the image display unit 400 to display the refreshed image from the frame buffer 210. 320 is notified.

  When the images displayed on the image display unit 400 are the same before and after the refresh by referring to such notification, the DMA control unit 320 displays the image after the refresh at the time of the refresh. It is not necessary to read out all of the image data to be displayed on the frame buffer 210 from the frame buffer 210. In other words, the DMA control unit 320 refers to such notification, and when the images displayed on the image display unit 400 are the same before and after the refresh, for the pixels having different pixel values from the basic data. Only reading from the frame buffer 210 is sufficient. That is, in this embodiment, the DMA control unit 320 and the determination result storage unit 350 function as a pixel information acquisition control unit.

  Therefore, according to the image display device 1 according to the present embodiment, it is possible to reduce the number of accesses to the shared memory 200 due to reading of image data in the image display control device 300 accompanying the refresh, and it is used only as a frame buffer. It is no longer necessary to provide a dedicated memory.

  Thus, the image display apparatus according to the present embodiment can reduce the occupation of the memory bus band of the shared memory 200 by the image display control apparatus with a simple and inexpensive configuration when displaying an image.

  Note that, as described above, the DMA control unit 320 according to the present embodiment, only when the images displayed on the image display unit 400 are the same before and after the refresh, only for pixels having different pixel values from the basic data. Since the data is read from the frame buffer 210 and the image data for displaying the refreshed image on the image display unit 400 is closer to the basic data, the above effect becomes greater.

  Here, the comparison determination processing unit 330 according to the present embodiment compares the pixel values of the basic data and the image data for each pixel to determine whether or not they are the same, and stores the determination result in the determination result storage unit 350. The image data, the basic data, and the determination result when doing so will be described with reference to FIGS.

  FIG. 2 is a diagram illustrating an example of a data structure of image data according to the present embodiment. 3 and 5 are diagrams showing an example of the data structure of basic data stored in the basic data storage unit 340 according to the present embodiment. 4 and 6 are diagrams illustrating examples of determination results stored in the determination result storage unit 350 according to the present embodiment.

  As shown in FIG. 2, the image data according to the present embodiment includes 20 pixels in the horizontal direction and 12 pixels in the vertical direction, and the pixel value of each pixel is represented by 2 bits. Further, each pixel included in such image data is identified by a combination of a coordinate in the horizontal direction and a coordinate in the vertical direction. If the coordinate in the horizontal direction is “X” and the coordinate in the vertical direction is “Y”, ( X, Y).

  In the example shown in FIG. 2, (14,3), (14,4), (14,5), (14,3), (15,4), (15,5), (15,3) , (15,4), (15,5) and (3,8), (3,9), (3,10), (4,8), (4,9), (4,10), ( For the pixels represented by 5, 8), (5, 9), and (5, 10), the pixel value is “3”, and for the other pixels, the pixel value is “2”. In FIG. 2, the pixel whose pixel value is “3” is shaded.

  For such image data, when the basic data storage unit 340 stores, for example, basic data in which the pixel values of all the pixels are “2” as illustrated in FIG. 3, the comparison according to the present embodiment is performed. The determination processing unit 330 includes (14, 3), (14, 4), (14, 5), (14, 3), (15, 4), (15, 5), (15, 3), (15 , 4), (15, 5) and (3, 8), (3, 9), (3, 10), (4, 8), (4, 9), (4, 10), (5, 8 ), (5, 9), and (5, 10), the pixel values of the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320 are the same. It is determined that they are different, and the other pixels are determined to be the same.

  Therefore, as shown in FIG. 4, the determination result storage unit 350 stores (14, 3), (14, 4), (14, 5), (14, 3), (15, 4) as determination results. , (15,5), (15,3), (15,4), (15,5) and (3,8), (3,9), (3,10), (4,8), ( 4,9), (4,10), (5,8), (5,9), (5,10) is “1”, and other pixels are “0”. Will be stored. In FIG. 4, the pixel value of the determination result “1”, that is, the pixel value of the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320 are different. The determined pixels are shaded.

  Then, the DMA controller 320 notified of the determination result as shown in FIG. 4 is (14, 3), (14, 4), (14, 5), (14, 3), (15, 4), (15,5), (15,3), (15,4), (15,5) and (3,8), (3,9), (3,10), (4,8), (4 , 9), (4, 10), (5, 8), (5, 9), and (5, 10), only the pixels represented by the frame buffer 210 are read out.

  As another example, when basic data having different pixel values for each pixel is stored in the basic data storage unit 340 with respect to the image data as shown in FIG. 2, for example, as shown in FIG. (3,7), (3,8), (3,9), (4,7), (4,8), (4,9), (5,7), (5,8), (5,9), (6,7), (6,8), (6,9), (7,7), (7,8), (7,9), (8,7), (8 , 8), (8, 9), (9, 7), (9, 8), (9, 9) and (16, 2), (16, 3), (16, 4), (16, 5 ), (16, 6), (16, 7), (16, 8), (17, 2), (17, 3), (17, 4), (17, 5), (17, 6), For the pixels represented by (17, 7) and (17, 8), the pixel value is “3”. For the other pixels, when basic data having a pixel value “2” is stored, the comparison determination processing unit 330 according to the present embodiment performs (3, 7), (3, 9), (3 , 10), (4, 7), (4, 9), (4, 10), (5, 7), (5, 9), (5, 10), (6, 7), (6, 8 ), (7, 7), (7, 8), (8, 7), (8, 8), (9, 7), (9, 8) and (14, 3), (14, 4), (14,5), (15,3), (15,4), (15,5), (16,2), (17,2), (17,3), (17,4), (17 , 5), (17, 6), (17, 7), and (17, 8) are input from the basic data stored in the basic data storage unit 340 and the DMA control unit 320. The pixel value is different from the image data It determines that determines that for the other pixels are the same.

  In FIG. 5, the pixel whose pixel value is “3” is shaded. Further, in FIG. 6, when the pixel value of the pixel whose determination result is “1”, that is, the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320 are different. The determined pixels are shaded.

  Then, the DMA controller 320 notified of the determination result as shown in FIG. 6 is (3, 7), (3, 9), (3, 10), (4, 7), (4, 9), (4,10), (5,7), (5,9), (5,10), (6,7), (6,8), (7,7), (7,8), (8 , 7), (8, 8), (9, 7), (9, 8) and (14, 3), (14, 4), (14, 5), (15, 3), (15, 4) ), (15, 5), (16, 2), (17, 2), (17, 3), (17, 4), (17, 5), (17, 6), (17, 7), Only the pixel represented by (17, 8) is read from the frame buffer 210.

  As described above, when the images displayed before and after the refresh are the same, the DMA control unit 320 according to the present embodiment notifies the determination result from the determination result storage unit 350 and refers to the determination result. This eliminates the need to read all the image data for displaying the refreshed image on the image display unit 400 from the frame buffer 210. That is, when the images displayed before and after the refresh are the same, the DMA control unit 320 according to the present embodiment notifies the determination result from the determination result storage unit 350 and refers to the determination result. Only the pixels whose pixel values are different from the basic data need only be read from the frame buffer 210.

  Therefore, according to the image display device 1 according to the present embodiment, the image display control device 300 according to the refresh reads the image data without providing a dedicated memory used only as a frame buffer separately from the shared memory 200. The number of accesses to the shared memory 200 can be reduced.

  Note that, as described above, the DMA control unit 320 according to the present embodiment, only when the images displayed on the image display unit 400 are the same before and after the refresh, only for pixels having different pixel values from the basic data. Since the data is read from the frame buffer 210 and the image data for displaying the refreshed image on the image display unit 400 is closer to the basic data, the above effect becomes greater.

  The display data generation unit 360 generates display data for causing the image display unit 400 to display an image based on the image data input from the DMA control unit 320 for each refresh. However, the display data generation unit 360 reads the basic data from the basic data storage unit 340 when it receives notification from the main control unit 310 that the images displayed before and after the refresh are the same. Display data is generated based on the read basic data and the image data input from the DMA control unit 320. Then, the display data generation unit 360 inputs the generated display data to the display control signal generation unit 370.

  That is, when the display data generation unit 360 receives notification from the main control unit 310 that the images displayed before and after the refresh are the same, the pixel value is set to the basic data from the DMA control unit 320. Only the pixels different from those are input, and only the pixels other than the pixels are read from the basic data storage unit 340. Then, the display data generation unit 360 generates display data based on the pixels input from the DMA control unit 320 and the pixels read from the basic data storage unit 340. That is, in the present embodiment, the display data generating unit 360 functions as a pixel information combining unit, and display data is generated as a combined image.

  For example, the image data read out by the DMA control unit 320 before refreshing and currently displayed is the image data shown in FIG. 2, and the basic data stored in the basic data storage unit 340 is the basic data shown in FIG. In some cases, only the pixels in the shaded area shown in FIG. 4 are input from the DMA control unit 320 to the display data generation unit 360 as image data to be displayed after the refresh, and other data are input from the basic data storage unit 340. Read only for the pixels. Then, the display data generation unit 360 merges both the pixels to generate display data.

  In the present embodiment, as described above, the display data generation unit 360 receives the notification that the images displayed before and after the refresh are the same from the main control unit 310, as described above. An example in which only the pixels other than the pixels input from the DMA control unit 320 are read from the basic data storage unit 340 and the display data is generated from the data storage unit 340 will be described.

  In addition to this configuration, when the display data generation unit 360 receives notification from the main control unit 310 that the images displayed before and after the refresh are the same, the display data generation unit 360 starts from the basic data storage unit 340. All basic data is read, and for pixels other than the pixels input from the DMA control unit 320, display data is generated using only necessary pixels among the basic data read from the basic data storage unit 340. May be.

  The display control signal generation unit 370 generates a display control signal that is a signal for measuring the timing in the horizontal direction when an image is displayed on the image display unit 400. That is, when the image display unit 400 displays an image, the image is first displayed on the upper left of the screen, moved in parallel to the right to display further images, and when reaching the right end, the image is displayed one step down and from left to right. To do. This is repeated to the lowest level, and the same scanning is repeated from the upper left. The display control signal determines the horizontal timing when performing these operations. Then, the display control signal generation unit 370 inputs the display data input from the display data generation unit 360 to the image display unit 400 in accordance with the generated display control signal, and the image display unit 400 based on the display data. Display the image. That is, in the present embodiment, the display control signal generation unit 370 functions as an update processing unit.

  As described above, the image display unit 400 is an image display unit such as a cathode ray tube display, a liquid crystal display, an organic EL display, or an LED display, and displays the display data input by the display control signal generation unit 370 according to the display control signal. Display the based image.

  In addition, the image display device 1 may be configured to include a ROM (Read Only Memory), a nonvolatile memory, a HDD (Hard Disc Drive), and a nonvolatile storage medium such as an optical disk (not shown).

  Next, the comparison determination processing unit 330 according to this embodiment performs pixel values of the basic data stored in the basic data storage unit 340 and the (N + 1) th frame image data input from the DMA control unit 320. Are compared for each pixel to determine whether or not they are the same, and the determination result is stored in the determination result storage unit 350, that is, the comparison determination processing by the comparison determination processing unit 330 according to the present embodiment. This will be described with reference to FIG. FIG. 7 is a flowchart for explaining the procedure of the comparison determination process by the comparison determination processing unit 330 according to the present embodiment. In FIG. 7, a process executed when refreshing from the Nth frame to the (N + 1) th frame will be described.

  As shown in FIG. 7, the comparison determination processing unit 330 according to the present embodiment first performs a comparison determination process at the time of refresh from the Nth frame to the (N + 1) th frame from the DMA control unit 320. When image data for (N + 1) frame is input (S701), the determination result storage unit 350 is initialized (S702). After initialization, the comparison determination processing unit 330 reads basic data from the basic data storage unit 340 (S703), and sets pixel values of the read basic data and the image data input from the DMA control unit 320 for each pixel. It is determined whether or not they are the same (S704).

  When the comparison determination processing unit 330 determines that the pixel value of the pixel currently focused on is the same between the basic data and the image data (S704 / YES), “0” is determined as the determination result. The result is stored in the result storage unit 350 (S705).

  On the other hand, if the comparison determination processing unit 330 determines that the pixel value of the currently focused pixel is different between the basic data and the image data (S704 / NO), “1” is stored as the determination result. The data is stored in the part 350 (S706).

  At this time, the comparison determination processing unit 330 compares the basic data and the image data in order from the upper left pixel to the right pixel to determine whether or not the pixel values are the same, and determines the determination result as the determination result. Store in the storage unit 350. Then, the comparison determination processing unit 330 goes down one step when reaching the right end and repeats the same processing from the left to the right, and repeats such processing up to the lowest step (S707 / YES, S708), thereby converting the image data. When the comparison determination for all the included pixels is completed (S707 / YES), the comparison determination process ends.

  Note that FIG. 2 is read from the basic data storage unit 340 for the image data input from the DMA control unit 320 to the comparison determination processing unit 330 during the comparison determination processing by the comparison determination processing unit 330. 3 and 5 for the basic data, and FIG. 4 and FIG. 6 for the determination result stored in the determination result storage unit 350 by the comparison determination processing unit 330.

  Next, the processing when the DMA control unit 320 according to the present embodiment reads image data for the (N + 2) th frame from the frame buffer 210 based on the determination result notified from the determination result storage unit 350, that is, The image data read processing by the DMA control unit 320 according to the present embodiment will be described with reference to FIG. FIG. 8 is a flowchart for explaining the procedure of image data read processing by the DMA control unit 320 according to this embodiment. In FIG. 8, a process executed at the time of refresh from the (N + 1) th frame to the (N + 2) th frame will be described.

  As shown in FIG. 8, the DMA control unit 320 according to the present embodiment first performs the image data reading process at the time of refresh from the (N + 1) th frame to the (N + 2) th frame. When the determination result is notified (S801), it is determined for each pixel whether the determination result is “0” or “1” (S802).

  If the DMA control unit 320 determines that the determination result for the currently focused pixel is “1” (S802 / YES), the pixel corresponding to the determination result is read from the frame buffer 210. Is input to the display data generation unit 360 (S803).

  On the other hand, when the DMA control unit 320 determines that the determination result for the currently focused pixel is “0” (S802 / NO), the pixel corresponding to the determination result is read from the frame buffer 210. Without reading, a flag indicating that basic data is used (hereinafter referred to as a “basic data use flag”) is generated and input to the display data generating unit 360 (S804).

  At this time, the DMA control unit 320 determines whether the determination result is “0” or “1” in order from the upper left pixel to the right pixel, and the frame buffer 210 is determined according to the determination result. The image data is read out and input to the display data generation unit 360, or a basic data use flag is generated and input to the display data generation unit 360. Then, when the DMA control unit 320 reaches the right end, it goes down one step and repeats the same processing from left to right, and repeats such processing up to the lowest step (S805 / YES, S806), thereby generating display data. When the comparison determination for all the pixels to be input to the unit 360 is completed (S805 / YES), the reading process ends.

  Next, the display data generation unit 360 according to the present embodiment displays the display for the (N + 2) th frame based on the image data input from the DMA control unit 320 and the basic data read from the basic data storage unit 340. Processing for generating display data, that is, display data generation processing by the display data generation unit 360 according to the present embodiment will be described with reference to FIG. FIG. 9 is a flowchart illustrating the procedure of display data generation processing by the display data generation unit 360 according to the present embodiment. In FIG. 9, a process executed when refreshing from the (N + 1) th frame to the (N + 2) th frame will be described.

  As shown in FIG. 9, the display data generation unit 360 according to the present embodiment first performs DMA control in order to perform display data generation processing when refreshing from the (N + 1) th frame to the (N + 2) th frame. When image data for the (N + 2) th frame is input from the unit 320 or a basic data use flag is input (S901), it is determined for each pixel which one is input (S902).

  When the display data generation unit 360 determines that image data has been input from the DMA control unit 320 for the pixel of interest (S902 / YES), the display data generation unit 360 receives the pixel from the DMA control unit 320. The input image data is adopted as display data (S903).

  On the other hand, if the display data generation unit 360 determines that the basic data use flag has been input from the DMA control unit 320 for the currently focused pixel (S902 / NO), the display data generation unit 360 uses the pixel corresponding to the pixel as the basic data. Data is read from the data storage unit 340 (S904). Then, the display data generation unit 360 employs the basic data read from the basic data storage unit 340 for the pixel as display data (S905).

  At this time, the display data generation unit 360 receives image data from the DMA control unit 320 in order from the upper left pixel to the right pixel, or a basic data use flag, and which of them is input. In accordance with the determination result, image data is adopted as display data, or basic data is adopted as display data.

  Then, the display data generation unit 360 goes down one step when reaching the right end and repeats the same processing from the left to the right, and repeats such processing up to the lowest step (S906 / YES, S907), thereby performing DMA control. When the adoption of the display data for all the pixels input from the unit 320 is completed (S906 / YES), the display data is generated by merging the image data and the basic data adopted as the display data (S908). . The display data generation unit 360 inputs the generated display data to the display control signal generation unit 370 (S909), and ends the display data generation process.

  As described above, in the image display device 1 according to the present embodiment, the DMA control unit 320 determines that the determination result storage unit is the same when the images displayed on the image display unit 400 are the same before and after the refresh. By notifying the determination result from 350 and referring to the determination result, it is not necessary to read out all of the image data for displaying the refreshed image on the image display unit 400 from the frame buffer 210 during the refresh. That is, in the image display apparatus 1 according to the present embodiment, the DMA control unit 320 determines that the determination result is stored from the determination result storage unit 350 when the images displayed on the image display unit 400 are the same before and after the refresh. By being notified and referring to the determination result, it is only necessary to read out from the frame buffer 210 only pixels having a pixel value different from the basic data.

  Therefore, according to the image display device 1 according to the present embodiment, it is possible to reduce the number of accesses to the shared memory 200 due to reading of image data in the image display control device 300 accompanying the refresh, and it is used only as a frame buffer. It is no longer necessary to provide a dedicated memory.

  Thereby, the image display device 1 according to the present embodiment can reduce the occupation of the memory bus band of the shared memory 200 by the image display control device with a simple and inexpensive configuration when displaying an image.

  Note that, as described above, the DMA control unit 320 according to the present embodiment, only when the images displayed on the image display unit 400 are the same before and after the refresh, only for pixels having different pixel values from the basic data. Since the data is read from the frame buffer 210 and the image data for displaying the refreshed image on the image display unit 400 is closer to the basic data, the above effect becomes greater.

Embodiment 2. FIG.
In the first embodiment, an example has been described in which the comparison determination processing unit 330 performs the comparison determination processing in units of pixels when the images displayed on the image display unit 400 are the same before and after the refresh. . In this case, when the images displayed on the image display unit 400 are the same before and after refreshing, the image display control device 300 only reads out from the frame buffer 210 only pixels whose basic data and pixel values are different at the time of refreshing. Good.

  On the other hand, in the present embodiment, when the images displayed on the image display unit 400 are the same before and after the refresh, the comparison determination processing unit 330 performs the comparison determination process before executing the comparison determination process. An example in which a plurality of areas are set in the image data to be subjected to the comparison and the comparison determination process is executed in units of the set areas will be described.

  In this case, when a different pixel is found during the execution of the comparison determination process, the comparison determination processing unit 330 ends the comparison determination process for the area including the pixel and executes the comparison determination process for the next area. Therefore, the time required for the comparison determination process can be shortened, and the maximum refresh rate can be improved.

  Further, in this case, unlike the first embodiment, the determination result storage unit 350 only stores the determination result by the comparison determination processing unit 330 for each region, not for each pixel. The capacity can be reduced.

  Therefore, according to the image display device 1 according to the present embodiment, in addition to the first embodiment, it is possible to display moving images more smoothly, increase the screen resolution and the number of simultaneous colors, and further reduce flicker. In addition, the material cost can be reduced and the circuit can be simplified.

  As a result, the image display device 1 according to the present embodiment reduces the occupation of the memory bus bandwidth of the shared memory 200 by the image display control device 300 with a simpler and less expensive configuration when displaying an image, and also displays a display image. Image quality and visibility can be improved. Details will be described below. In addition, about the structure which attaches | subjects the code | symbol similar to Embodiment 1, it shall show the same or an equivalent part, and abbreviate | omits detailed description.

  First, the hardware configuration of the image display apparatus 1 according to the present embodiment will be described with reference to FIG. FIG. 10 is a block diagram schematically showing a hardware configuration of the image display apparatus 1 according to the present embodiment. As illustrated in FIG. 10, the image display device 1 according to the present embodiment includes a determination result temporary storage unit 380 that is different from the first embodiment. The determination result temporary storage unit 380 temporarily stores a determination result in the middle of the comparison determination process in the comparison determination processing unit 330.

  Next, functions of the comparison determination processing unit 330 according to the present embodiment will be described. Similar to the first embodiment, the comparison determination processing unit 330 according to the present embodiment receives a notification from the main control unit 310 that the images displayed before and after the refresh are the same. The pixel values of the basic data stored in the data storage unit 340 and the image data input from the DMA control unit 320 are compared for each pixel to determine whether or not they are the same.

  However, the comparison determination processing unit 330 according to the present embodiment is different from the first embodiment in that the determination result at this time is not a final determination result but an intermediate determination result, and the intermediate determination result is determined as the determination result. The data is stored in the temporary storage unit 380 for each pixel.

  That is, if the comparison determination processing unit 330 determines that the pixel values of the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320 are the same, the pixel If “0” is determined as the determination result for “”, and “1” is stored as the determination result for the pixel in the determination result temporary storage unit 380.

  Also, unlike the first embodiment, the comparison determination processing unit 330 according to the present embodiment adds a plurality of regions to the image data input from the DMA control unit 320 before executing the comparison determination processing as described above. Set. In the present embodiment, such a function provided by the comparison determination processing unit 330 is one of the gist.

  At this time, a state when the comparison determination processing unit 330 according to the present embodiment sets a plurality of areas in the image data input from the DMA control unit 320 will be described with reference to FIG. FIG. 11 is a diagram illustrating an example of a plurality of areas set in the image data input from the DMA control unit 320 by the comparison determination processing unit 330 according to the present embodiment. Note that the image data shown in FIG. 11 is the same image data as the image data shown in FIG.

  As illustrated in FIG. 11, the comparison determination processing unit 330 according to the present embodiment includes a plurality of pixels so that each region includes 2 pixels × 3 pixels = 4 pixels with respect to the image data input from the DMA control unit 320. Set the area. As described above, each region included in the image data in which a plurality of regions are set is identified by a combination of the coordinate in the horizontal direction and the coordinate in the vertical direction. The coordinate in the horizontal direction is “P”, and the coordinate in the vertical direction is “ Q ”is represented by (P, Q).

  Then, when the comparison determination processing unit 330 according to the present embodiment sets a plurality of regions for the image data in this way, the comparison determination processing is executed in units of the set regions. At this time, as in the first embodiment, the comparison determination processing unit 330 according to the present embodiment is a pixel of basic data stored in the basic data storage unit 340 and image data input from the DMA control unit 320. If it is determined that the values are the same, “0” is stored in the determination result temporary storage unit 380 as the determination result for that pixel.

  However, when the comparison determination processing unit 330 according to the present embodiment determines that the pixel values of the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320 are different, For the region including the pixel, even if the comparison determination process has already been completed and “0” is stored in the determination result storage unit 350 as a determination result, or a pixel that has not yet completed the comparison determination process is included, “1” is stored as a determination result in the determination result temporary storage unit 380, and the comparison determination process for the region including the pixel is terminated. In the present embodiment, such a function provided by the comparison determination processing unit 330 is one of the gist.

  For example, for the image data in which a plurality of areas as shown in FIG. 11 are set, the basic data storage unit 340 stores, for example, basic data having pixel values “2” as shown in FIG. When stored, the comparison / determination processing unit 330 according to the present embodiment performs (14, 3), (14, 4), (14, 5), (14, 3) as shown in FIG. ), (15, 4), (15, 5), (15, 3), (15, 4), (15, 5) and (3, 8), (3, 9), (3, 10), The pixels represented by (4, 8), (4, 9), (4, 10), (5, 8), (5, 9), (5, 10) are stored in the basic data storage unit 340. It is determined that the pixel value of the basic data that has been changed and the image data input from the DMA control unit 320 are different, but as described above, either Once it is determined that becomes, for a region including the pixel is stored in the determination result temporary storage section 380 as a determination result to "1", and ends the comparison determination processing for a region including the pixel. Then, when the comparison determination processing unit 330 according to the present embodiment finishes the comparison determination processing for all regions, the determination result is read from the determination result temporary storage unit 380 as the final determination result and stored in the determination result storage unit 350.

  Therefore, as shown in FIG. 12, the determination result storage unit 350 has (2, 4), (2, 5), (3,4), (3, 5) and (7 as final determination results. , 2), (7, 3), (8, 2), and (8, 3), “1” is stored, and “0” is stored for the other regions. FIG. 12 is a diagram illustrating an example of a final determination result stored in the determination result storage unit 350 according to the present embodiment. In FIG. 12, the pixel value of the region including the pixel whose determination result is “1”, that is, the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320. A region including pixels determined to be different from each other is shaded.

  Then, the DMA controller 320 notified of the determination result as shown in FIG. 12 is (2, 4), (2, 5), (3,4), (3, 5) and (7, 2), Only the pixels included in the area represented by (7, 3), (8, 2), (8, 3) are read from the frame buffer 210.

  As another example, for example, when basic data having different pixel values for each pixel is stored in the basic data storage unit 340 for image data in which a plurality of areas as shown in FIG. 11 are set. For example, as shown in FIG. 5, (3,7), (3,8), (3,9), (4,7), (4,8), (4,9), (5,7 ), (5,8), (5,9), (6,7), (6,8), (6,9), (7,7), (7,8), (7,9), (8,7), (8,8), (8,9), (9,7), (9,8), (9,9) and (16,2), (16,3), (16 , 4), (16, 5), (16, 6), (16, 7), (16, 8), (17, 2), (17, 3), (17, 4), (17, 5 ), (17, 6), (17, 7), (17, 8) When the basic data having the pixel value “3” and the pixel value “2” is stored for the other pixels, the comparison determination processing unit 330 according to the present embodiment is shown in FIG. As shown, (3,7), (3,9), (3,10), (4,7), (4,9), (4,10), (5,7), ( 5,9), (5,10), (6,7), (6,8), (7,7), (7,8), (8,7), (8,8), (9, 7), (9, 8) and (14, 3), (14, 4), (14, 5) (15, 3), (15, 4), (15, 5), (16, 2) ), (17,2), (17,3), (17,4), (17,5), (17,6), (17,7), (17,8) , Basic data stored in the basic data storage unit 340, and D Although it is determined that the pixel value is different from the image data input from the A control unit 320, when it is determined that any of the pixel values is different, “1” is determined as a determination result for a region including the pixel. The comparison determination processing for the area including the pixel is completed. Then, when the comparison determination processing unit 330 according to the present embodiment finishes the comparison determination processing for all regions, the determination result is read from the determination result temporary storage unit 380 as the final determination result and stored in the determination result storage unit 350.

  Therefore, as shown in FIG. 13, the determination result storage unit 350 has (2, 4), (2, 5), (3,4), (3, 5), (4) as final determination results. , 3), (5, 3) and (7, 2), (7, 3), (8, 1), (8, 2), (8, 3), (8, 4), (9, 1 ), (9, 2), (9, 3), and (9, 4), “1” is stored, and “0” is stored for the other regions. FIG. 13 is a diagram illustrating an example of a final determination result stored in the determination result storage unit 350 according to the present embodiment. In FIG. 13, the pixel value of the region including the pixel whose determination result is “1”, that is, the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320. A region including pixels determined to be different from each other is shaded.

  Then, the DMA control unit 320 notified of the determination result as shown in FIG. 13 is (2, 4), (2, 5), (3,4), (3, 5), (4, 3), (5,3) and (7,2), (7,3), (8,1), (8,2), (8,3), (8,4), (9,1), (9 , 2), (9, 3), and (9, 4), only the pixels included in the area are read from the frame buffer 210.

  As described above, the comparison determination processing unit 330 according to the present embodiment ends the comparison determination process for the region including the pixel at the time when a different pixel is found during the execution of the comparison determination process, and performs the process for the next region. Since the comparison determination process can be executed, the time required for the comparison determination process can be shortened, and the maximum refresh rate can be improved.

  Further, as described above, the determination result storage unit 350 according to the present embodiment only needs to store the determination result by the comparison determination processing unit 330 for each region, and the storage capacity of the determination result storage unit 350 can be reduced. It becomes.

  Therefore, according to the image display device 1 according to the present embodiment, in addition to the first embodiment, it is possible to display moving images more smoothly, increase the screen resolution and the number of simultaneous colors, and further reduce flicker. In addition, the material cost can be reduced and the circuit can be simplified.

  Next, the comparison determination processing unit 330 according to this embodiment performs pixel values of the basic data stored in the basic data storage unit 340 and the (N + 1) th frame image data input from the DMA control unit 320. Are compared for each pixel, and the determination result is temporarily stored in the determination result temporary storage unit 380, and the final determination result is stored in the determination result storage unit 350. That is, the comparison determination process performed by the comparison determination processing unit 330 according to the present embodiment will be described with reference to FIG. FIG. 14 is a flowchart for explaining the procedure of the comparison determination process by the comparison determination processing unit 330 according to the present embodiment. In FIG. 14, a process executed when refreshing from the Nth frame to the (N + 1) th frame will be described.

  As shown in FIG. 14, when performing the comparison determination process, the comparison determination processing unit 330 according to the present embodiment first receives image data for the (N + 1) th frame from the DMA control unit 320 (S1401). ), The determination result temporary storage unit 380 is initialized (S1402). After initialization, the comparison determination processing unit 330 reads the basic data from the basic data storage unit 340 (S1403), and the read basic data and the image data input from the DMA control unit 320 are shown in FIG. The area is set as follows (1304).

  After setting the area, the comparison determination processing unit 330 compares the pixel values of the read basic data and the image data input from the DMA control unit 320 for each pixel and determines whether or not they are the same (S1405). If the comparison determination processing unit 330 determines that the pixel value of the currently focused pixel is the same between the basic data and the image data (S1405 / YES), it determines “0” as the determination result. The result is temporarily stored in the storage unit 380 (S1406).

  On the other hand, when the comparison determination processing unit 330 determines that the pixel value of the pixel currently focused on is different between the basic data and the image data (S1405 / NO), the determination result is obtained for the region including the target pixel. “1” is stored in the determination result temporary storage unit 380 (S1407).

  At this time, the comparison determination processing unit 330 compares the basic data and the image data in order from the upper left pixel to the right pixel in the region that is the target of the comparison determination process, and whether or not the pixel values are the same. The determination result is stored in the determination result temporary storage unit 380. Then, the comparison determination processing unit 330 goes down one step when the right end is reached for the region to be compared and repeats the same processing from left to right (S1408 / NO, S1409). Repeat until the lower level (S1408 / YES).

  The comparison determination processing unit 330 repeatedly performs such processing for each region (S1410 / NO, S1411), and completes the comparison determination for all pixels included in the image data (S1410 / YES). The determination result temporarily stored in the temporary storage unit 380 is read out, stored in the determination result storage unit 350 as the final determination result (S1412), and the comparison determination process ends.

  Note that FIG. 2 is read from the basic data storage unit 340 for the image data input from the DMA control unit 320 to the comparison determination processing unit 330 during the comparison determination processing by the comparison determination processing unit 330. 3 and 5 for the basic data, and FIG. 12 and FIG. 13 for the determination result stored in the determination result storage unit 350 by the comparison determination processing unit 330.

  As described above, in the image display apparatus 1 according to the present embodiment, the comparison determination processing unit 330 performs the comparison determination when the images displayed on the image display unit 400 are the same before and after the refresh. Before executing the process, a plurality of areas are set in the image data to be subjected to the comparison determination process, and the comparison determination process is executed for each set area.

  In this case, when a different pixel is found during the execution of the comparison determination process, the comparison determination processing unit 330 ends the comparison determination process for the area including the pixel and executes the comparison determination process for the next area. Therefore, the time required for the comparison determination process can be shortened, and the maximum refresh rate can be improved.

  Further, in this case, unlike the first embodiment, the determination result storage unit 350 only stores the determination result by the comparison determination processing unit 330 for each region, not for each pixel. The capacity can be reduced.

  Therefore, according to the image display device 1 according to the present embodiment, in addition to the first embodiment, it is possible to display moving images more smoothly, increase the screen resolution and the number of simultaneous colors, and further reduce flicker. In addition, the material cost can be reduced and the circuit can be simplified.

  As a result, the image display device 1 according to the present embodiment reduces the occupation of the memory bus bandwidth of the shared memory 200 by the image display control device 300 with a simpler and less expensive configuration when displaying an image, and also displays a display image. Image quality and visibility can be improved.

Embodiment 3 FIG.
In the first embodiment, an example has been described in which the comparison determination processing unit 330 performs the comparison determination processing in units of pixels when the images displayed on the image display unit 400 are the same before and after the refresh. . In this case, when the images displayed on the image display unit 400 are the same before and after refreshing, the image display control device 300 only reads out from the frame buffer 210 only pixels whose basic data and pixel values are different at the time of refreshing. Good.

  In the second embodiment, when the images displayed on the image display unit 400 are the same before and after the refresh, the comparison determination processing unit 330 performs the comparison determination process before executing the comparison determination process. The example in which a plurality of areas are set in the target image data and the comparison determination process is executed in units of the set areas has been described. In this case, when a different pixel is found during the execution of the comparison determination process, the comparison determination processing unit 330 ends the comparison determination process for the area including the pixel and executes the comparison determination process for the next area. Therefore, the time required for the comparison determination process can be shortened. In this case, the determination result storage unit 350 only needs to store the determination result by the comparison determination processing unit 330 for each region, and the storage capacity of the determination result storage unit 350 can be reduced.

  On the other hand, in the present embodiment, when the images displayed on the image display unit 400 are the same before and after the refresh, the comparison determination processing unit 330 performs the comparison determination process before executing the comparison determination process. A plurality of areas are set independently for the horizontal and vertical directions of the image data subject to image processing, and the area set in the horizontal direction and the area set in the vertical direction are compared and determined for each area independently. An example of executing and integrating the result of the comparison determination process in the horizontal direction and the vertical direction will be described. In this case, when a different pixel is found during the execution of the comparison determination process, the comparison determination processing unit 330 ends the comparison determination process for the area including the pixel and executes the comparison determination process for the next area. Therefore, as in the second embodiment, the time required for the comparison determination process can be shortened, and the maximum refresh rate can be improved. Further, in this case, the determination result storage unit 350 only needs to store the determination result by the comparison determination processing unit 330 for each region, and the storage capacity of the determination result storage unit 350 is reduced as in the second embodiment. Is possible.

  Therefore, according to the image display apparatus 1 according to the present embodiment, in addition to the first embodiment, similarly to the second embodiment, the moving image is displayed more smoothly, the screen resolution and the number of simultaneous colors are increased, and the flickering is further performed. Can be reduced, the material cost can be reduced, and the circuit can be simplified.

  As a result, the image display device 1 according to the present embodiment reduces the occupation of the memory bus bandwidth of the shared memory 200 by the image display control device 300 with a simpler and less expensive configuration when displaying an image, and also displays a display image. Image quality and visibility can be improved. Details will be described below. In addition, about the structure which attaches | subjects the code | symbol similar to Embodiment 1 and 2, it shall show the same or an equivalent part, and abbreviate | omits detailed description.

  First, the function of the comparison determination processing unit 330 according to the present embodiment will be described. Similar to the first embodiment, the comparison determination processing unit 330 according to the present embodiment receives a notification from the main control unit 310 that the images displayed before and after the refresh are the same. The pixel values of the basic data stored in the data storage unit 340 and the image data input from the DMA control unit 320 are compared for each pixel to determine whether or not they are the same.

  However, the comparison determination processing unit 330 according to the present embodiment is different from the first embodiment, like the second embodiment, the determination result at this time is not a final determination result but an intermediate determination result, The determination result in the middle is stored in the determination result temporary storage unit 380 for each pixel.

  That is, if the comparison determination processing unit 330 determines that the pixel values of the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320 are the same, the pixel If “0” is determined as the determination result for “”, and “1” is stored as the determination result for the pixel in the determination result temporary storage unit 380.

  Also, unlike the first and second embodiments, the comparison determination processing unit 330 according to the present embodiment is the horizontal direction of image data input from the DMA control unit 320 before executing the comparison determination processing as described above. A plurality of areas are set independently in the vertical direction. In the present embodiment, such a function provided by the comparison determination processing unit 330 is one of the gist.

  At this time, a state when the comparison determination processing unit 330 according to the present embodiment sets a plurality of regions in the horizontal direction of the image data input from the DMA control unit 320 will be described with reference to FIG. In addition, a state when the comparison determination processing unit 330 according to the present embodiment sets a plurality of regions in the vertical direction of the image data input from the DMA control unit 320 will be described with reference to FIG. FIG. 15 is a diagram illustrating an example of a plurality of areas set in the horizontal direction of the image data input from the DMA control unit 320 by the comparison determination processing unit 330 according to the present embodiment. FIG. 16 is a diagram illustrating an example of a plurality of areas set in the vertical direction of the image data input from the DMA control unit 320 by the comparison determination processing unit 330 according to the present embodiment. The image data shown in FIGS. 15 and 16 is the same image data as the image data shown in FIG.

  As illustrated in FIG. 15, the comparison determination processing unit 330 according to the present embodiment includes a plurality of regions in the horizontal direction so that the image data input from the DMA control unit 320 includes two pixels in the horizontal direction. Set. As described above, each region included in the image data in which a plurality of regions are set in the horizontal direction is identified by the coordinate in the horizontal direction. If the coordinate in the horizontal direction is “P”, the coordinate in the vertical direction is irrelevant. , (P,).

  Also, as shown in FIG. 16, the comparison determination processing unit 330 according to the present embodiment includes a plurality of pixels in the vertical direction so that the image data input from the DMA control unit 320 includes two pixels in the vertical direction. Set the area. As described above, each area included in the image data in which a plurality of areas are set in the vertical direction is identified by a combination of coordinates in the vertical direction. The coordinates in the vertical direction are “Q”, and the coordinates in the horizontal direction are related. Since there is no, it is represented by (, Q).

  Then, when the comparison determination processing unit 330 according to the present embodiment sets a plurality of areas independently in the horizontal direction and the vertical direction for the image data as described above, the comparison determination processing unit 330 executes the comparison determination process for each set area. . At this time, the comparison determination processing unit 330 according to the present embodiment, as in the first and second embodiments, includes the basic data stored in the basic data storage unit 340, the image data input from the DMA control unit 320, and the like. When it is determined that the pixel values of the pixels are the same, “0” is stored in the determination result temporary storage unit 380 as the determination result for that pixel.

  However, when the comparison determination processing unit 330 according to the present embodiment determines that the pixel values of the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320 are different, For the region including the pixel, even if the comparison determination process has already been completed and “0” is stored in the determination result storage unit 350 as a determination result, or a pixel that has not yet completed the comparison determination process is included, “1” is stored as a determination result in the determination result temporary storage unit 380, and the comparison determination process for the region including the pixel is terminated. In the present embodiment, such a function provided by the comparison determination processing unit 330 is one of the gist.

  For example, for image data in which a plurality of regions are set in the horizontal direction as shown in FIG. 15, the pixel values of all the pixels as shown in FIG. 3 are “2” in the basic data storage unit 340, for example. When basic data is stored, the comparison / determination processing unit 330 according to the present embodiment performs (14, 3), (14, 4), (14, 5), ( 14,3), (15,4), (15,5), (15,3), (15,4), (15,5) and (3,8), (3,9), (3, 10), (4,8), (4,9), (4,10), (5,8), (5,9), (5,10), the basic data storage unit It is determined that the pixel values of the basic data stored in 340 and the image data input from the DMA control unit 320 are different. Once it is determined also differs from at or Re, the area including the pixel is stored in the determination result temporary storage section 380 as a determination result to "1", and ends the comparison determination processing for a region including the pixel.

  Accordingly, as shown in FIG. 17, the determination result temporary storage unit 380 stores “1” for the regions represented by (2,), (3), (7,), (8,) as the determination results. ", But" 0 "is stored for other areas. FIG. 17 is a diagram illustrating an example of a determination result stored in the determination result temporary storage unit 380 according to the present embodiment. In FIG. 17, the pixel value of the region including the pixel whose determination result is “1”, that is, the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320. A region including pixels determined to be different from each other is shaded.

  For example, for the image data in which a plurality of areas are set in the vertical direction as shown in FIG. 16, the pixel values of all the pixels as shown in FIG. In the same manner as shown in FIG. 4, the comparison determination processing unit 330 according to the present embodiment (14, 3), (14, 4), (14, 5) is stored. , (14, 3), (15, 4), (15, 5), (15, 3), (15, 4), (15, 5) and (3, 8), (3, 9), ( 3,10), (4,8), (4,9), (4,10), (5,8), (5,9), (5,10), the basic data Although it is determined that the basic data stored in the storage unit 340 and the image data input from the DMA control unit 320 have different pixel values, as described above. , When it is determined also differs from either, the area including the pixel is stored in the determination result temporary storage section 380 as a determination result to "1", and ends the comparison determination processing for a region including the pixel.

  Accordingly, as shown in FIG. 18, the determination result temporary storage unit 380 stores “1” for the areas represented by (, 2), (, 3), (, 4), and (, 5) as the determination results. ", But" 0 "is stored for other areas. FIG. 18 is a diagram illustrating an example of determination results stored in the determination result temporary storage unit 380 according to the present embodiment. In FIG. 18, the pixel value of the region including the pixel whose determination result is “1”, that is, the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320. A region including pixels determined to be different from each other is shaded.

  Then, when the comparison determination processing unit 330 according to the present embodiment finishes the comparison determination processing in the horizontal direction and the vertical direction, the determination results are integrated and the final determination result is stored in the determination result temporary storage unit 380. . Specifically, the comparison determination processing unit 330 according to the present embodiment determines that the pixel values of the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320 are different. For a region where both the horizontal direction region and the vertical direction region including the pixels overlap, that is, the region where both the shaded regions in FIG. 17 and FIG. For other areas, “0” is stored in the determination result temporary storage unit 380 as a determination result. Hereinafter, such processing by the comparison determination processing unit 330 according to the present embodiment is referred to as determination result integration processing. Then, after completing the determination result integration process, the comparison determination processing unit 330 according to the present embodiment reads out the determination result from the determination result temporary storage unit 380 as the final determination result and stores it in the determination result storage unit 350 for comparison determination. The process ends.

  As a result, as shown in FIG. 19, the determination result storage unit 350 stores (2, 2), (2, 3), (2, 4), (2, 5), ( 3,2), (3,3), (3,4), (3,5) and (7,2), (7,3), (7,4), (7,5), (8, 2), “8” is stored for the areas represented by (8, 3), (8, 4), and (8, 5), and “0” is stored for the other areas. FIG. 19 is a diagram illustrating an example of a final determination result stored in the determination result storage unit 350 according to the present embodiment. In FIG. 19, the pixel value of the region including the pixel whose determination result is “1”, that is, the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320. A region including pixels determined to be different from each other is shaded.

  Then, the DMA control unit 320 notified of the determination result as shown in FIG. 19 is (2, 2), (2, 3), (2, 4), (2, 5), (3, 2), (3,3), (3,4), (3,5) and (7,2), (7,3), (7,4), (7,5), (8,2), (8 , 3), (8, 4), and (8, 5), only the pixels included in the area are read from the frame buffer 210.

  As another example, for example, basic data having different pixel values for each pixel is stored in the basic data storage unit 340 for image data in which a plurality of regions are set in the horizontal direction as shown in FIG. For example, as shown in FIG. 5, (3, 7), (3, 8), (3, 9), (4, 7), (4, 8), (4, 9), ( 5,7), (5,8), (5,9), (6,7), (6,8), (6,9), (7,7), (7,8), (7, 9), (8, 7), (8, 8), (8, 9), (9, 7), (9, 8), (9, 9) and (16, 2), (16, 3) , (16, 4), (16, 5), (16, 6), (16, 7), (16, 8), (17, 2), (17, 3), (17, 4), ( 17, 5), (17, 6), (17, 7), (17, 8) In the case where basic data having a pixel value of “3” is stored for the prime and the pixel value of “2” is stored for the other pixels, the comparison determination processing unit 330 according to the present embodiment (3,7), (3,9), (3,10), (4,7), (4,9), (4,10), (5,7) as shown in FIG. , (5,9), (5,10), (6,7), (6,8), (7,7), (7,8), (8,7), (8,8), ( 9,7), (9,8), and (14,3), (14,4), (14,5) (15,3), (15,4), (15,5), (16 , 2), (17, 2), (17, 3), (17, 4), (17, 5), (17, 6), (17, 7), (17, 8) Is the basic data stored in the basic data storage unit 340. And the image data input from the DMA control unit 320 are different from each other. However, as described above, when any of the pixel values is determined to be different, “1” is set for the area including the pixel. The determination result is stored in the determination result temporary storage unit 380, and the comparison determination process for the region including the pixel ends.

  Therefore, as shown in FIG. 20, the determination result temporary storage unit 380 has (2,), (3), (4), (5), (7,), (8, ), (9,) stores “1”, and other regions store “0”. FIG. 20 is a diagram illustrating an example of determination results stored in the determination result temporary storage unit 380 according to the present embodiment. In FIG. 20, the pixel value of the region including the pixel whose determination result is “1”, that is, the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320. A region including pixels determined to be different from each other is shaded.

  Further, for example, when basic data having different pixel values for each pixel is stored in the basic data storage unit 340 with respect to image data in which a plurality of areas are set in the vertical direction as shown in FIG. 5, (3,7), (3,8), (3,9), (4,7), (4,8), (4,9), (5,7), (5,8), (5,9), (6,7), (6,8), (6,9), (7,7), (7,8), (7,9), (8 , 7), (8, 8), (8, 9), (9, 7), (9, 8), (9, 9) and (16, 2), (16, 3), (16, 4) ), (16, 5), (16, 6), (16, 7), (16, 8), (17, 2), (17, 3), (17, 4), (17, 5), For the pixels represented by (17,6), (17,7), (17,8) When the basic data having the pixel value “3” and the pixel value “2” is stored for the other pixels, the comparison determination processing unit 330 according to this embodiment is shown in FIG. (3,7), (3,9), (3,10), (4,7), (4,9), (4,10), (5,7), (5 , 9), (5, 10), (6, 7), (6, 8), (7, 7), (7, 8), (8, 7), (8, 8), (9, 7 ), (9, 8) and (14, 3), (14, 4), (14, 5) (15, 3), (15, 4), (15, 5), (16, 2) , (17,2), (17,3), (17,4), (17,5), (17,6), (17,7), and (17,8), Basic data stored in the basic data storage unit 340 and DMA Although it is determined that the pixel value is different from the image data input from the control unit 320, as described above, when it is determined that any of the pixel values is different, “1” is determined as the determination result for the region including the pixel. The result is stored in the temporary storage unit 380, and the comparison determination process for the region including the pixel ends.

  Therefore, as shown in FIG. 21, in the determination result temporary storage unit 380, the determination result is represented by (, 1), (, 2), (, 3), (, 4), (, 5). “1” is stored for the area, and “0” is stored for the other areas. FIG. 21 is a diagram illustrating an example of determination results stored in the determination result temporary storage unit 380 according to the present embodiment. In FIG. 21, a pixel value of an area including a pixel whose determination result is “1”, that is, basic data stored in the basic data storage unit 340 and image data input from the DMA control unit 320. A region including pixels determined to be different from each other is shaded.

  The comparison determination processing unit 330 according to the present embodiment includes pixels determined to have different pixel values between the basic data stored in the basic data storage unit 340 and the image data input from the DMA control unit 320. For a region where both the region in the horizontal direction and the region in the vertical direction overlap, that is, for the region where both the shaded regions in FIGS. 20 and 21 overlap, the determination result “1” is given to the other region. Is stored in the determination result temporary storage unit 380 as a determination result. Then, after completing the determination result integration process, the comparison determination processing unit 330 according to the present embodiment reads out the determination result from the determination result temporary storage unit 380 as the final determination result and stores it in the determination result storage unit 350 for comparison determination. The process ends.

  As a result, as shown in FIG. 22, the determination result storage unit 350 has (2, 1), (2, 2), (2, 3), (2, 4), ( 2,5), (3,1), (3,2), (3,3), (3,4), (3,5), (4,1), (4,2), (4 3), (4,4), (4,5), (5,1), (5,2), (5,3), (5,4), (5,5), (7,1) , (7, 2), (7, 3), (7, 4), (7, 5), (8, 1), (8, 2), (8, 3), (8, 4), ( “1” is stored for the area represented by (8, 5), and “0” is stored for the other areas. FIG. 22 is a diagram illustrating an example of a final determination result stored in the determination result storage unit 350 according to the present embodiment. In FIG. 22, the region where the determination result in the horizontal direction is “1” and the determination result in the vertical direction is “1” is shown shaded.

  Then, the DMA control unit 320 notified of the determination result as shown in FIG. 22 is (2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (3,1), (3,2), (3,3), (3,4), (3,5), (4,1), (4,2), (4,3), (4 , 4), (4, 5), (5, 1), (5, 2), (5, 3), (5, 4), (5, 5), (7, 1), (7, 2 ), (7, 3), (7, 4), (7, 5), (8, 1), (8, 2), (8, 3), (8, 4), (8, 5) Only the pixels included in the represented area are read from the frame buffer 210.

  As described above, the comparison determination processing unit 330 according to the present embodiment ends the comparison determination process for the region including the pixel at the time when a different pixel is found during the execution of the comparison determination process, and performs the process for the next region. Since the comparison determination process can be executed, the time required for the comparison determination process can be shortened, and the maximum refresh rate can be improved.

  Further, as described above, the determination result storage unit 350 according to the present embodiment only needs to store the determination result by the comparison determination processing unit 330 for each region, and the storage capacity of the determination result storage unit 350 can be reduced. It becomes.

  Therefore, according to the image display device 1 according to the present embodiment, in addition to the first embodiment, similarly to the second embodiment, the moving image is displayed more smoothly, the screen resolution and the number of simultaneous colors are increased, Thus, flicker can be reduced, material cost can be reduced, and the circuit can be simplified.

  Next, the comparison determination processing unit 330 according to this embodiment performs pixel values of the basic data stored in the basic data storage unit 340 and the (N + 1) th frame image data input from the DMA control unit 320. Are compared for each pixel in the region set in the horizontal direction to determine whether or not they are the same, the determination result is temporarily stored in the determination result temporary storage unit 380, and the final determination result is stored in the determination result The processing when storing in the unit 350, that is, the comparison determination processing for the region set in the horizontal direction by the comparison determination processing unit 330 according to the present embodiment will be described with reference to FIG. FIG. 23 is a flowchart for explaining the procedure of the comparison determination process in the horizontal direction by the comparison determination processing unit 330 according to this embodiment. In FIG. 23, processing executed when refreshing from the Nth frame to the (N + 1) th frame will be described.

  As shown in FIG. 23, when performing comparison determination processing, the comparison determination processing unit 330 according to the present embodiment first receives image data for the (N + 1) th frame from the DMA control unit 320 (S2301). ), The determination result temporary storage unit 380 is initialized (S2302). After initialization, the comparison determination processing unit 330 reads the basic data from the basic data storage unit 340 (S2303), and the read basic data and the image data input from the DMA control unit 320 are shown in FIG. Thus, an area is set in the horizontal direction (2204).

  After setting the region in the horizontal direction, the comparison determination processing unit 330 compares the pixel values of the read basic data and the image data input from the DMA control unit 320 for each pixel and determines whether or not they are the same. (S2305). When the comparison determination processing unit 330 determines that the pixel value of the currently focused pixel is the same between the basic data and the image data (S2305 / YES), it determines “0” as the determination result. The result is temporarily stored in the storage unit 380 (S2306).

  On the other hand, when the comparison determination processing unit 330 determines that the pixel value of the pixel currently focused on is different between the basic data and the image data (S2305 / NO), the determination result is obtained for the region including the target pixel. “1” is stored in the determination result temporary storage unit 380 (S2307).

  At this time, the comparison determination processing unit 330 compares the basic data and the image data in order from the upper left pixel to the right pixel in the region that is the target of the comparison determination process, and whether or not the pixel values are the same. The determination result is stored in the determination result temporary storage unit 380. Then, the comparison determination processing unit 330 goes down one step when the right end is reached for the region to be subjected to the comparison determination processing, and repeats the same processing from the left to the right (S2308 / NO, S2309). Repeat until the lower level (S2308 / YES).

  When the comparison determination processing unit 330 repeatedly performs such processing for each region (S2310 / NO, S2311), and completes the comparison determination for all the pixels included in the image data (S2310 / YES), the horizontal direction The comparison determination process for is terminated.

  And the comparison determination process part 330 which concerns on this embodiment will start the comparison determination process with respect to a perpendicular direction, after finishing the comparison determination process with respect to a horizontal direction. Since the processing at this time is the same as the comparison determination processing for the horizontal direction, detailed description thereof is omitted.

  It should be noted that the image data input from the DMA control unit 320 to the comparison determination processing unit 330 during the comparison determination processing in the horizontal direction and the vertical direction by the comparison determination processing unit 330 is shown in FIG. 15 and FIG. 3 and 5 for the basic data that the processing unit 330 reads from the basic data storage unit 340, and the determination results of the comparison determination processing in the horizontal direction and the vertical direction by the comparison determination processing unit 330, respectively. See FIG. 19 and FIG. 22 for the final determination result that the comparison determination processing unit 330 stores in FIG. 18 and FIG. 21 in the determination result storage unit 350.

  Thus, the comparison determination processing unit 330 according to the present embodiment performs a determination result integration process for integrating the determination results after completing the comparison determination process for the horizontal direction and the vertical direction. Then, after completing the determination result integration process, the comparison determination processing unit 330 reads out from the determination result temporary storage unit 380 as a final determination result, stores it in the determination result storage unit 350, and ends the comparison determination process.

  Here, the comparison determination processing unit 330 according to the present embodiment integrates the determination results of the comparison determination processing in the horizontal direction and the vertical direction, reads out the determination result from the determination result temporary storage unit 380 as the final determination result, and stores the determination result. The processing at the time of storing in the unit 350, that is, the determination result integration processing by the comparison determination processing unit 330 according to the present embodiment will be described with reference to FIG. FIG. 24 is a flowchart for explaining the procedure of determination result integration processing by the comparison determination processing unit 330 according to this embodiment.

  As shown in FIG. 24, when performing the determination result integration process, the comparison determination processing unit 330 according to the present embodiment first determines the determination result of the comparison determination process for the horizontal direction and the determination result of the comparison determination process for the vertical direction. The areas are set so that the areas in and are shared with each other (S2401). The comparison determination processing unit 330 calculates the logical product of the determination result of the comparison determination process for the horizontal direction and the determination result of the comparison determination process for the vertical direction for each region set in the process of S2401 (S2402). The calculation result is stored in the determination result temporary storage unit 380 as the final determination result (S2403).

  At this time, the comparison determination processing unit 330 calculates a logical product of the determination result of the comparison determination process for the horizontal direction and the determination result of the comparison determination process for the vertical direction in order from the upper left region to the right region, The determination result is stored in the determination result temporary storage unit 380 as a final determination result. When the comparison determination processing unit 330 reaches the right end, it goes down one step and repeats the same processing from the left to the right. By repeating such processing up to the lowest step (S2404 / YES, S2405), the image data is processed. When the integration of the determination results for all the included areas is completed (S2404 / YES), the determination result temporarily stored in the determination result temporary storage unit 380 is read, and the final determination result is stored in the determination result storage unit 350. Store (S2406), and the comparison determination process ends.

  As described above, in the image display apparatus 1 according to the present embodiment, the comparison determination processing unit 330 performs the comparison determination when the images displayed on the image display unit 400 are the same before and after the refresh. Before executing the comparison determination process, the processing unit 330 sets a plurality of areas independently in the horizontal direction and the vertical direction of the image data to be subjected to the comparison determination process, and is perpendicular to the area set in the horizontal direction. A description will be given of an example in which the comparison determination process is performed independently for each region set in the direction, and the result of the comparison determination process is integrated in the horizontal direction and the vertical direction. In this case, when a different pixel is found during the execution of the comparison determination process, the comparison determination processing unit 330 ends the comparison determination process for the area including the pixel and executes the comparison determination process for the next area. Therefore, as in the second embodiment, the time required for the comparison determination process can be shortened, and the maximum refresh rate can be improved. Further, in this case, the determination result storage unit 350 only needs to store the determination result by the comparison determination processing unit 330 for each region, and the storage capacity of the determination result storage unit 350 is reduced as in the second embodiment. Is possible.

  Therefore, according to the image display apparatus 1 according to the present embodiment, in addition to the first embodiment, similarly to the second embodiment, the moving image is displayed more smoothly, the screen resolution and the number of simultaneous colors are increased, and the flickering is further performed. Can be reduced, the material cost can be reduced, and the circuit can be simplified.

  As a result, the image display device 1 according to the present embodiment reduces the occupation of the memory bus bandwidth of the shared memory 200 by the image display control device 300 with a simpler and less expensive configuration when displaying an image, and also displays a display image. Image quality and visibility can be improved.

  In the first to third embodiments, an image display device including an image display unit such as a cathode ray tube display, a liquid crystal display, an organic EL display, and an LED display has been described as an example. The present invention can be similarly applied to an image projection display device such as a projector that displays an image on a projection surface such as a wall or a screen by projecting the image as light.

  In the first to third embodiments, the processor 100, the shared memory 200, and the image display control device 300 have been described as examples provided inside the image display device 1, but each is provided separately from the image display device 1. The image display device 1 may be controlled from the outside.

  In the present embodiment, the example in which the image data is composed of one layer has been described. However, the present invention can be similarly applied even when the image data is composed of a plurality of layers, for example, layers of each color. . In this case, the comparison determination processing unit 330 performs comparison determination processing and determination result integration processing for each layer, the basic data storage unit 340 stores basic data for each layer, and the determination result storage unit 350 and the determination result The temporary storage unit 380 is configured to store the determination result for each layer.

  In the first to third embodiments, the comparison determination processing unit 330 has been described with respect to the example in which the comparison determination process is performed on the entire image data. However, the same region is displayed in the images displayed before and after the refresh. It may be configured to perform the above-described comparison determination process only for. In this case, the comparison determination processing unit 330 is configured to be notified from the main control unit 310 of the same region in the image displayed before and after the refresh, and thereby the region for performing the comparison determination process. Is detected.

  According to the image display device 1 in which the comparison / determination processing unit 330 is configured in this way, even if the images displayed before and after the refresh are different, the region in which both are the same is refreshed. Accordingly, it is possible to reduce the number of accesses to the frame buffer 210 by reading image data in the image display control apparatus 300.

  Thereby, the image display apparatus according to the present embodiment can further reduce the occupation of the memory bus band of the shared memory 200 by the image display control apparatus with a simple and inexpensive configuration when displaying an image.

  In the first to third embodiments, the comparison determination processing unit 330 receives the notification that the images displayed before and after the refresh are the same from the main control unit 310 and performs the comparison determination processing. The example of performing the above has been described, but the comparison determination process is not performed when there is no notification.

  In the first to third embodiments, the DMA control unit 320 has been described as an example configured to input the image data acquired from the frame buffer 210 to the display data generation unit 360. When the images displayed on the image display unit 400 are different from each other, the display data generation unit 360 may be directly input.

DESCRIPTION OF SYMBOLS 1 Image display apparatus 100 Processor 200 Shared memory 210 Frame buffer 300 Image display control apparatus 310 Main control part 320 DMA control part 330 Comparison determination processing part 340 Basic data storage part 350 Determination result storage part 360 Display data generation part 370 Display control signal Generation unit 380 Determination result temporary storage unit 400 Image display unit

JP 2003-288067 A

Claims (9)

An image display control device that updates the display of the image display unit every predetermined period,
A pixel information acquisition unit that acquires pixel information of each pixel constituting an image to be displayed on the image display unit in a certain period from an external storage medium;
An update processing unit that updates the display of the image display unit based on the acquired pixel information;
A reference pixel information storage unit storing reference pixel information indicating a reference density in the display of the image display unit;
A comparison processing unit that performs a comparison process for storing a comparison result between the acquired pixel information and the reference pixel information in a storage medium for each pixel constituting an image for displaying on the image display unit;
In updating the display of the image display unit for the next period of the certain period, based on the comparison result, only the pixel information of a pixel different from the reference pixel information is acquired from the external storage medium. A pixel information acquisition control unit for operating the information acquisition unit;
A pixel information combining unit that combines pixel information of a pixel different from the reference pixel information acquired based on the comparison result and the reference pixel information to generate a combined image for display on the image display unit; Including
The image display control apparatus, wherein the update processing unit updates display of the image display unit for a period subsequent to the certain period based on the composite image. The comparison processing unit performs the comparison when an image to be displayed on the image display unit in the certain period is the same as an image to be displayed on the image display unit in the next period of the certain period. Store the result in a storage medium,
The pixel information combining unit is configured such that when an image to be displayed on the image display unit in the certain period is the same as an image to be displayed on the image display unit in a period subsequent to the certain period, Generate a composite image,
The update processing unit, when the image to be displayed on the image display unit in the certain period and the image to be displayed on the image display unit in the next period of the certain period are the same, The image display control apparatus according to claim 1, wherein the display of the image display unit for the next period of the certain period is updated based on the image. The comparison processing unit performs the comparison processing in a predetermined area unit,
When updating the display of the image display unit for the next period of the certain period, the pixel information acquisition control unit is configured to update only the pixel information of a region including a pixel different from the reference pixel information based on the comparison result. The image display control apparatus according to claim 1, wherein the pixel information acquisition unit is operated so as to be acquired from the storage medium. The comparison determination processing unit performs the comparison process independently for a first predetermined area unit and a second predetermined area unit different from the first predetermined area,
When the display of the image display unit for the next period after the certain period is updated, the pixel information acquisition control unit performs the comparison result for the first predetermined area unit and the second predetermined area unit. Based on the comparison result, a region including a pixel different from the reference pixel information in the first predetermined region and a region including a pixel different from the reference pixel information in the second predetermined region are provided. 4. The image display control apparatus according to claim 1, wherein the pixel information acquisition unit is operated so that only pixel information of an overlapping region is acquired from the external storage medium. 5.   The comparison processing unit ends the comparison process for the region when a pixel having pixel information different from the reference pixel information appears in the region where the comparison process is performed, and performs the comparison process for the next region. The image display control device according to claim 3, wherein the image display control device is performed.   The image display control apparatus according to claim 1, wherein the comparison processing unit performs the comparison processing for each layer when the image data includes a plurality of layers.   The comparison processing unit, when updating the display of the image display unit for the next period of the certain period, the image to be displayed on the image display unit in the certain period and the period in the next period of the certain period The image display control apparatus according to claim 1, wherein the comparison process is performed only for a region where an image to be displayed on the image display unit is the same.   An image display device comprising the image display control device according to claim 1. An image display control method for updating the display of the image display unit every predetermined period,
Obtaining pixel information of each pixel constituting an image to be displayed on the image display unit in a certain period from an external storage medium;
A comparison result between the acquired pixel information and reference pixel information indicating a reference density in display of the image display unit is stored in a storage medium for each pixel constituting an image to be displayed on the image display unit. Perform a comparison process,
In updating the display of the image display unit for the next period of the certain period, based on the comparison result, only the pixel information of a pixel different from the reference pixel information is acquired from the external storage medium. Operate the information acquisition unit,
Generating a composite image for displaying on the image display unit by combining pixel information of the pixel different from the reference pixel information acquired based on the comparison result and the reference pixel information;
An image display control method, comprising: updating display of the image display unit for a period subsequent to the certain period based on the composite image.