JP2009115858A - Image display system, information apparatus, display control device, display control method, display control program and computer readable recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a higher update rate of drawing a display image data after subjected to a rotation processing by carrying out in parallel a transfer processing of the display image data and the rotation processing of the display image data. <P>SOLUTION: An image display system has a liquid crystal controller 200 including: a host IF 240 that writes the display image data transferred from a display data generating device 300 into a RAM 210; and a rotation processing unit 250 that rotates the display image data on the RAM 210. The liquid crystal controller 200 controls the host IF 240 such that the display image data transferred from the display data generating device 300 is written in the RAM 210 at timing of starting the rotation processing of the display image data by the rotation processing unit 250. Thereby, the rotation processing and the transfer processing of the display image data can be carried out parallel. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an information device capable of outputting an image to a display device, and more particularly to an information device that needs to rotate and display an image created by an application.

  Conventionally, as an information device capable of outputting an image to a display device, for example, a mobile phone can be cited.

  FIG. 8 shows a schematic block diagram of an image display system mounted on a mobile phone.

  As shown in FIG. 8, the image display system includes a liquid crystal display device 1100 that is a display device, a liquid crystal controller 1200 that transmits display image data to the liquid crystal display device 1100, and display data that generates display image data. Generation device 1300.

  The display data generation apparatus 1300 includes a host CPU 1310 and a RAM 1320, and display image data is generated by an application executed on the host CPU 1310.

  By the way, some recent cellular phones have a function of rotating a display unit for displaying an image with respect to a main body device.

  For example, there is no problem when the orientation of the image generated by the above-described application and the scanning direction of the liquid crystal display device 1100 match, but when they do not match, it is necessary to rotate the image so that they match. is there. That is, it is necessary to perform processing (rotation processing) that matches the display image data generated by the application with the scanning direction of the liquid crystal display device 1100.

  In the image display system shown in FIG. 8, the display data generation device 1300 or the liquid crystal controller 1200 performs the rotation process on the display image data.

  When the display data generating apparatus 1300 performs rotation processing on the display image data, the rotation processing is performed in the display image data generation stage by software running on the host CPU 1310. In this case, in the display data generating apparatus 1300, the software performs arithmetic processing for obtaining an address of the RAM that is changed as the display image data is rotated, and the display image data associated with the rotation processing is calculated. Due to the large number of random accesses, it takes time to obtain image data for display that has been subjected to rotation processing. As a result, it takes a very long time to update the drawing, resulting in a problem that the drawing cannot be updated at high speed.

  In order to solve this problem, it is conceivable to update the drawing at a high speed by increasing the transfer speed of the display image data that has been subjected to the rotation process from the host CPU 1310 of the display data generating apparatus 1300 to the liquid crystal controller 1200. For example, Patent Document 1 proposes a method of efficiently performing image data transfer control and transferring data from a host CPU at high speed.

  However, as long as the display image data is generated on the display data generation device 1300 side in a rotated state, it takes time to generate the display image data, and the drawing update is performed only by increasing the data transfer speed. This causes a problem that it cannot be performed at high speed.

  On the other hand, when the rotation processing is performed on the display image data on the liquid crystal controller 1200 side, only the rotation processing is performed on the already generated display image data. As compared with the case where the rotation processing is performed on the image, the drawing update can be performed at high speed.

For example, Patent Document 2 discloses a technique for speeding up drawing update by performing display image data rotation processing on the display control device (corresponding to the liquid crystal controller 1200) side of an image display device.
JP 2002-149141 A (published on May 24, 2002) Japanese Unexamined Patent Publication No. 63-63281 (published on March 19, 1988)

  However, in Patent Document 2, communication is performed while handshaking with the host CPU, and communication is stopped during the rotation process. In other words, in the technique disclosed in Patent Document 2, the display image data transfer process and the display image data rotation process are not performed in parallel, but are performed sequentially. This causes a problem that high-speed drawing update of image data cannot be expected.

  The present invention has been made in view of the above-described problems, and the object of the present invention is to perform a rotation process by performing a display image data transfer process and a display image data rotation process in parallel. The purpose is to speed up the drawing update of display image data.

  In order to solve the above problems, an image display system according to the present invention reads necessary display image data from a display device capable of rotating a display unit for displaying an image and a memory storing the display image data. An image display system comprising: a display control device that transfers to the display unit; and a display image data generation device that generates and transfers the display image data to the display control device. A write unit that writes display image data transferred from the image data generation device to the memory, and a rotation processing unit that performs a rotation process on the display image data on the memory. The display image data transferred from the display image data generation device is written to the memory at the start timing of the image data rotation process. It is characterized by controlling the serial write unit.

  According to the above configuration, the display control device writes the display image data transferred from the display image data generation device into the memory at the start timing of the rotation processing of the display image data by the rotation processing unit. By controlling the write unit, the display image data transferred to the memory by the write unit can be written while the rotation processing unit is rotating the display image data.

  Accordingly, the rotation processing for the display image data by the rotation processing unit and the display image data transfer processing can be performed in parallel, so that the data transfer is stopped during the rotation processing as in the prior art. In addition, it is possible to speed up the drawing update of the rotation-processed display image data.

  The display control device causes the write unit to write the display image data generated by the display image data generation device into the memory in units of a plurality of lines, and the rotation processing unit writes the order to the memory. In this case, the display image data may be rotated.

  Thereby, the rotation process and the data transfer process can be performed in parallel in units of a plurality of lines.

  The display data storage area of the memory may have a double buffer configuration.

  As a result, the memory used can be minimized to minimize the increase in cost, and the control can be simplified to minimize the control overhead.

  The display control device reads the display image data stored in the memory in accordance with a synchronization signal at a predetermined timing by the synchronization control unit and transfers the read image data to the display device, and the rotation processing unit performs rotation processing. The image data for display may be provided in a display image data storage area that is read by the read unit of the memory, and a copy unit that collectively copies the display image data in the same direction as the scanning direction read by the read unit.

  As a result, even if the address direction on the memory of the image data after rotation is orthogonal to the scanning direction of the display device, that is, the data transfer direction, the entire updated image is processed and then copied in the same direction as the scanning direction of the display device In addition, by referring to the timing (synchronization signal) of the synchronization control unit, the read unit for reading the display image data to be transferred to the display device includes a memory part in which writing has not been completed and a memory part in which writing has been completed. As a result, the boundary line in the scanning direction can be made invisible in the display, so that the display quality can be ensured.

  The rotation processing unit includes a CPU and a local RAM, transfers part or all of the display image data written in the memory to the local RAM, and applies the display image data transferred to the local RAM to the display image data. The CPU may perform a rotation process, and the display image data subjected to the rotation process may be written in an area where the read unit of the memory reads data.

  Accordingly, a general-purpose CPU can be used for the rotation processing unit, and the present CPU can be used for other purposes such as image processing.

  As described above, in the image display system according to the present invention, the display control device writes the display image data transferred from the display image data generation device to the memory, and the display image on the memory. A rotation processing unit that performs rotation processing on the data, and the display image data transferred from the display image data generation device at the timing of starting the rotation processing of the display image data by the rotation processing unit. By controlling the write unit so as to write to the memory, it is possible to speed up the drawing update of the rotated display image data.

  An embodiment of the present invention will be described as follows.

  FIG. 1 is a block diagram showing a schematic configuration of an image display system of the present invention.

  As shown in FIG. 1, the image display system includes a liquid crystal display device 100, a liquid crystal controller (display control device) 200, and a display data generation device 300.

  The liquid crystal display device 100 includes a liquid crystal panel 110 and a liquid crystal driver 120.

  The liquid crystal controller 200 includes a RAM 210, a read unit 220, a synchronization control unit 230, a host IF 240, a rotation processing unit 250, an interrupt processing unit 260, and a status notification unit 270.

  The display data generation device 300 includes a host CPU 310 and a RAM 320.

  As described above, the liquid crystal controller 200 includes the RAM 210 that holds display image data, and sequentially transfers the display image data to the liquid crystal display device 100 for display.

  The synchronization control unit 230 generates timing information for timing of transferring display image data to the liquid crystal display device 100.

  The read unit 220 sequentially reads the display image data held in the RAM 210 in accordance with the timing information of the synchronization control unit 230, and transfers the data to the liquid crystal display device 100 in a predetermined format.

  The liquid crystal display device 100 includes the liquid crystal driver 120 as described above, and the liquid crystal driver 120 performs A / D conversion on the transferred display image data, and timing information from the synchronization control unit 230. Therefore, a timing signal required for the liquid crystal panel 110 is generated, the liquid crystal panel 110 is driven, and a predetermined image is displayed.

  The display image data is created by application software executed on the host CPU 310 in the display data generating apparatus 300 and transferred to the liquid crystal controller 200.

  Display image data created by the host CPU 310 is temporarily stored in a RAM 320 connected to the host CPU 310. When updating the drawing, the host CPU 310 reads the display image data from the RAM 320 and transfers it to the RAM 210 in the liquid crystal controller 200 via the host IF 240 in the liquid crystal controller 200. The RAM 210 is overwritten and saved, that is, the drawing is updated by the newly transferred display image data.

  As described above, the liquid crystal controller 200 includes the rotation processing unit 250, the interrupt processing unit 260 and the state notification unit 270 for linking the rotation processing unit 250 and the host CPU 310 of the display data generation device 300. Is provided.

  The status notification unit 270 includes a register that can be written from the host CPU 310 and can be read by the rotation processing unit 250, and a register that can be written by the rotation processing unit 250 and can be read by the host CPU 310.

  The interrupt processing unit 260 has a function of notifying the rotation processing unit 250 of an interrupt when the host CPU 310 writes to the register and a function of notifying the host CPU 310 of an interrupt when the rotation processing unit 250 writes to the register. .

  FIG. 2 is a diagram showing an outline of a mobile phone which is one of information devices equipped with the image display system having the above configuration.

  As shown in FIG. 2, the mobile phone main body is divided into two housings, an upper housing 1 and a lower housing 2, and an operation unit in which buttons or the like on the lower housing 2 side are arranged via hinges 3, respectively. 2a and the display unit 1a on which the liquid crystal panel 110 and the like on the upper housing 1 side are arranged can be folded so as to face each other.

  The liquid crystal panel 110 is provided with a source driver in the short side direction and a gate driver in the long side direction, and the scanning direction of the liquid crystal is a direction of scanning from the upper left to the upper right and further from the upper to the lower. The scanning direction is the order of data transmitted from the liquid crystal controller 200 to the liquid crystal display device 100 as data displayed on the liquid crystal.

  Further, as shown on the right side of FIG. 2, in the cellular phone, when the folding is opened, the upper casing 1 is further provided with a rail (not shown) provided on the back side of the display unit 1a or a second hinge. 2 (not shown), the state shown on the left side of FIG. 2 can be turned 90 degrees to the right to be in the horizontally long state, and the horizontally long image can be displayed in the horizontally long state. The liquid crystal panel 110 has a source driver arranged in the short side direction and a gate driver arranged in the long side direction. Therefore, in a state where the liquid crystal panel is tilted 90 degrees to the right, the liquid crystal scanning direction is sequentially from the upper right to the lower right. This is the direction of scanning from right to left.

  Here, the display unit 1a of the mobile phone on the left side and the display unit 1a of the mobile phone on the right side of FIG. 2 display the same moving image, but preferably, the decoding of the moving image is performed with the same application software in either state. The display image data should be generated, and therefore, the generated display image data is displayed on the liquid crystal panel 110 without rotating in accordance with the state of the mobile phone (mainly the rotation state of the display unit 1a). It is necessary to display the image on the liquid crystal panel 110 by rotating it.

  For this purpose, the rotation processing unit 250 of the liquid crystal controller 200 performs the rotation process on the display image data.

  FIG. 3 is a block diagram illustrating a schematic configuration of the rotation processing unit 250.

  The rotation processing unit 250 includes a CPU 251 that performs various processes, a bus IF 252 that is an interface between the RAM 210 that stores display image data in the liquid crystal controller 200, and a local that temporarily stores data for rotation processing. The RAM 253 is composed of a RAM 210 connected to the global bus via the bus IF 252 and a DMA controller (DMAC) 254 for transferring data between the local RAM 253.

  The CPU 251 has an interrupt processing function that accepts an interrupt signal from the outside and branches the processing. The interrupt signal at this time includes the interrupt signal notified from the interrupt processing unit 260 in the liquid crystal controller 200. That is, this is an interrupt signal for notifying that the host CPU 310 of the display data generating apparatus 300 has written to the register.

  That is, the rotation processing unit 250 transfers display image data from the display data generation device 300 to the liquid crystal controller 200 by cooperating with the host CPU 310 of the display data generation device 300 by transmitting and receiving the interrupt signal. And the rotation processing of the display image data in the liquid crystal controller 200 can be performed in parallel.

  FIG. 4 is a schematic diagram illustrating how the host CPU 310 and the rotation processing unit 250 perform image data transfer and rotation processing in cooperation with each other. In the following description, (1) to (4) respectively correspond to (1) to (4) shown in FIG.

  First, display image data generated by an application executed on the host CPU 310 is converted into rectangular image data and stored in the RAM 320 connected to the host CPU 310 in the display data generation apparatus 300.

  (1): Rectangular image data stored in the RAM 320 is divided into horizontally long regions of 2 lines in order from the top of the image, and transferred to a double buffer arranged in the RAM 210 inside the liquid crystal controller 200 line by line. At this time, when the RAM 320 connected to the host CPU 310 is a DRAM, reading in the horizontal direction, that is, the direction in which the DRAM addresses are continuous can be performed at high speed.

  (2): The host CPU 310 and the rotation processing unit 250 handshake via the status notification unit 270, and when the host CPU 310 notifies that the image data has been transferred to the double buffer, the rotation processing unit 250 uses the DMA controller 254. Then, the image data for two lines in the double buffer is once transferred to the local RAM 253 of the rotation processing unit 250. Now, even if the RAM 210 in the liquid crystal controller 200 is constituted by a DRAM, the double buffer read operation is a high-speed operation because it is a read in a direction in which addresses continue.

  (3): Next, the rotation processing unit 250 writes the display image data for two lines copied to the local RAM 253 to the copy buffer arranged in a part of the RAM 210 in the liquid crystal controller 200 two pixels at a time. And rotate.

  (4) When all the rectangular image data is transferred to the RAM 210 and the rotation processing is completed, the rotation processing unit 250 refers to the timing information of the synchronization control unit 230 and the display that the read unit 220 is transferring to the liquid crystal display device 100. Copy over the image data. At this time, copying starts immediately after the read unit 220 reads the longitudinal coordinates of the position where the rectangular image data is to be copied, and the rectangular image data is copied. As a result, the read unit 220 that reads display image data to be transferred to the liquid crystal display device 100 generates a timing to read the memory portion of the RAM 210 that has not been written and the memory portion that has been written as the same frame. Therefore, the boundary line in the scanning direction can be made invisible on the display, and the display quality can be ensured.

  The outline of the cooperative rotation processing between the host CPU 310 and the rotation processing unit 250 has been described above with reference to FIG. 4, but the processing on the host CPU 310 side and the processing on the rotation processing unit 250 side will be described in detail below. To do.

  Here, the status notification unit 270 is notified of two registers (host status A register and host status B register) for notifying the status from the host CPU 310 to the rotation processing unit 250, and the status is notified from the rotation processing unit 250 to the host CPU 310. It is assumed that two registers (rotation status A register and rotation status B register) are arranged. The register prohibition state refers to a state in which data reading and writing are prohibited, and the register permission state refers to a state in which data reading and writing are permitted.

  FIG. 5 is a flowchart showing the flow of cooperative rotation processing on the host CPU 310 side.

  First, when the cooperative rotation process is activated, the host status A register in the status notification unit 270 is disabled (step S1), and the host status B register is disabled (step S2).

  Next, the rotation status A register in the status notification unit 270 is polled and waits until it is in a permitted state (step S3).

  In step S3, when the rotation status A register is enabled, the host status A register is disabled (step S4), and the host status B register is enabled (step S5).

  Then, the end of the transfer of all data is determined (step S6). Here, the transfer of all data refers to all the display image data to be rotated at a time in the rotation processing unit 250 of the liquid crystal controller 200.

  If it is determined that all data has been transferred, it is determined whether or not the rotation status B register of the status notification unit 270 is in a permitted state (step S7), and the rotation status B register is in a permitted state. If there is, the host status B register is disabled (step S8), and the process is terminated.

  On the other hand, if it is determined in step S6 that all the data has not been transferred, the image data for two lines is transferred to the double buffer on the A side of the double buffers in the RAM 210 (step S9).

  Next, the rotation status B register in the status notification unit 270 is polled and waits until it is in a permitted state (step S10).

  In step S10, when the rotation status B register is enabled, the host status B register is disabled (step S11), and the host status A register is enabled (step S12).

  Then, the end of the transfer of all data is determined (step S13). Here, the transfer of all data refers to all the display image data to be rotated at a time in the rotation processing unit 250 of the liquid crystal controller 200.

  If it is determined that all data has been transferred, it is determined whether or not the rotation status A register of the status notification unit 270 is in a permitted state (step S14), and the rotation status A register is in a permitted state. If there is, the host status A register is disabled (step S15), and the process is terminated.

  On the other hand, if it is determined in step S13 that all data has not been transferred, two lines of image data are transferred to the double buffer on the B side of the double buffers in the RAM 210 (step S16), and step S3. Migrate to

  As described above, when the transfer of all the image data is completed, the rotation status register of the double buffer that has been transferred most recently is polled and waits until the permission state is reached. When the rotation status register is enabled, the host status register is disabled and the process ends.

  Next, cooperative rotation processing on the rotation processing unit 250 side will be described.

  FIG. 6 is a flowchart showing the flow of cooperative rotation processing in the CPU 251 of the rotation processing unit 250.

  Here, before the coordinated rotation process is started, the host CPU 310 in advance stores the size of the image to be rotated, position information to be overwritten on the displayed image, other double buffer, copy buffer, and display image data on the RAM. Information such as the address is notified to the rotation processing unit 250 as setting information.

  Thereafter, when notified of the start of cooperative rotation processing, the CPU 251 in the rotation processing unit 250 sets the rotation status A register of the state notification unit 270 to a permitted state (step S21), and sets the rotation status B register to a permitted state (step S21). Step S22).

  Next, the host status A register is polled and waits until it is in a permitted state (step S23).

  If the host status A register is enabled in step S23, the rotation status A register is disabled (step S24), and the A buffer is rotated (step S25). That is, the A side of the double buffer is copied to the local RAM 253 using the DMA controller 254, and stored in a state rotated to the copy buffer by software.

  Next, when the rotation process for the A surface is completed, the rotation status A register is set to the permitted state (step S26).

  Then, the end of the rotation process for all data is determined (step S27). Here, the rotation processing of all data refers to rotation of all display image data to be rotated at once in the rotation processing unit 250 of the liquid crystal controller 200.

  If it is determined that all data rotation processing has been completed, the process proceeds to step S33. If all data rotation processing has not been completed, the host status B register of the status notification unit 270 is polled. Wait until the permission state is reached (step S28).

  If the host status B register is enabled in step S28, the rotation status B register is disabled (step S29), and the double buffer B surface is rotated (step S30). That is, the B side of the double buffer is copied to the local RAM 253 using the DMA controller 254, and stored in a state rotated to the copy buffer by software.

  Next, when the rotation process for the B surface is completed, the rotation status B register is set to the permitted state (step S31).

  Subsequently, the end of the rotation processing of all data is determined (step S32). Here, the rotation processing of all data refers to rotation of all display image data to be rotated at once in the rotation processing unit 250 of the liquid crystal controller 200.

  If the rotation processing of all data has not been completed, the process proceeds to step S23. If the rotation processing of all data has been completed, the CPU 251 refers to the timing information of the synchronization control unit 230, and after the rotation, The process waits until the read position 220 immediately follows the vertical coordinate of the position where the rectangular image data is to be copied (step S33).

  When the predetermined timing is notified, the DMA controller 254 is activated to copy the rectangular image data to the display image data area of the RAM 210 (step S34).

  When the copy process ends, the host CPU 310 is notified of the end of the cooperative rotation process (step S35), and the process ends.

  As described above, the coordinated rotation process on the host CPU 310 side and the coordinated rotation process on the rotation processing unit 250 side have been described separately, but the overall flow in the coordinated rotation process will be described below.

  FIG. 7 is a sequence diagram showing the flow of the overall linkage process of the process of the host CPU 310 and the process of the rotation processing unit 250. In FIG. 7, the rotation processing CPU indicates the CPU 251 in the rotation processing unit 250.

  First, when the host CPU 310 generates image data to be displayed and updated, the host CPU 310 notifies the rotation processing unit 250 of setting information of the linked rotation process, and notifies the start of the linked rotation process. Thereafter, the host CPU 310 transfers the display image data to the double buffer A surface.

  After handshaking, the image data for display on the double buffer B surface is transferred from the host CPU 310, and at the same time, the rotation processing unit 250 rotates the image data for display already transferred to the double buffer A surface. Do.

  When the rotation processing unit 250 completes both the display image data transfer to the double buffer B surface and the rotation processing of the display image data transferred to the double buffer A surface by handshaking, the display image on the double buffer A surface is displayed. At the same time that the data is transferred from the host CPU 310, the rotation processing unit rotates the image data transferred to the double buffer B surface.

  When the rotation processing of the rotation processing unit 250 for all display image data is completed, the cooperative rotation processing on the host CPU 310 side ends, but the rotation processing unit 250 continues the processing and receives the timing information from the synchronization control unit 230. Referring to, a copy process to the display image area of RAM 210 is performed. When the copy process is completed, the rotation processing unit 250 notifies the host CPU 310 that the coordinated rotation process has been completed and that the next coordinated rotation process may be started.

  As a result, the transfer processing of the display image data from the host CPU 310 to the liquid crystal controller 200 and the rotation processing inside the liquid crystal controller 200 operate almost in parallel, so that the overhead for rotating display can be eliminated.

  In the present embodiment, as described above, the display quality is maintained by referring to the timing information from the synchronization control unit 230 and performing the copy process to the display image area of the RAM 210. However, the display quality is maintained. If it is desired to prioritize the drawing update rate, it is not necessary to wait for the timing of the synchronization control unit 230. In addition, when a plurality of rectangular image data is embedded in one display image and the drawing is updated, the above-described copying process may be performed collectively after performing a cooperative rotation process on the plurality of rectangular image data.

  In the present embodiment, since the interrupt is used for the setting information notification, the start notification, and the end notification of the coordinated rotation process, the rotation processing unit 250 performs another process when the coordinated rotation process is not performed. It is also possible to execute. The host CPU 310 can execute other processes after the transfer process is completed until the copy is completed. Note that these notification methods are not interrupts, and other methods may be used. For example, when the notification is performed by a register, the rotation processing unit 250 can wait for the start of the next cooperative rotation process by register polling after the rotation process is completed. When starting the next cooperative rotation process, the host CPU 310 may start after waiting for the end of the previous cooperative rotation process by register polling.

  Furthermore, in this embodiment, since the register polling is performed using the state notification unit 270 regarding the transfer processing state and the rotation processing state during the cooperative rotation processing, it occurs during the single rotation processing of one rectangular image data. The overhead of many handshakes can be minimized. If priority is given to low power consumption over minimizing overhead due to handshaking, an interrupt is used for this handshake information, and either or both of the host CPU 310 and the CPU 251 of the rotation processing unit 250 stop the clock. The CPU, whichever is faster of the transfer process or the rotation process, can be frequently reduced to the low power consumption state.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  Finally, each block of the liquid crystal controller 200, in particular, the rotation processing unit 250 may be configured by hardware logic, or may be realized by software using a CPU as follows.

  That is, the liquid crystal controller 200 includes a CPU (central processing unit) that executes instructions of a control program for realizing each function, a ROM (read only memory) that stores the program, a RAM (random access memory) that expands the program, A storage device (recording medium) such as a memory for storing the program and various data is provided. An object of the present invention is to provide a recording medium on which a program code (execution format program, intermediate code program, source program) of a control program of the liquid crystal controller 200, which is software that realizes the functions described above, is recorded so as to be readable by a computer. This can also be achieved by supplying the liquid crystal controller 200 and reading and executing the program code recorded on the recording medium by the computer (or CPU or MPU).

  Examples of the recording medium include a tape system such as a magnetic tape and a cassette tape, a magnetic disk such as a floppy (registered trademark) disk / hard disk, and an optical disk such as a CD-ROM / MO / MD / DVD / CD-R. Card system such as IC card, IC card (including memory card) / optical card, or semiconductor memory system such as mask ROM / EPROM / EEPROM / flash ROM.

  Further, the liquid crystal controller 200 may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited. For example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication. A net or the like is available. Also, the transmission medium constituting the communication network is not particularly limited. For example, even in the case of wired such as IEEE 1394, USB, power line carrier, cable TV line, telephone line, ADSL line, etc., infrared rays such as IrDA and remote control, Bluetooth ( (Registered trademark), 802.11 wireless, HDR, mobile phone network, satellite line, terrestrial digital network, and the like can also be used. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

  The image display system of the present invention is mainly used in a mobile phone whose display unit can be rotated. When the scanning direction of the display unit and the scanning direction of the display image data do not match, the display is made to match. The present invention can be applied to any device as long as it is an information device that needs to rotate image data.

It is a block diagram which shows schematic structure of the image display system of this invention. It is a figure which shows the outline of the mobile telephone carrying the image display system shown in FIG. It is a block diagram which shows schematic structure of the rotation process part with which the image display system shown in FIG. 1 was equipped. It is the schematic which showed a mode that a host CPU and a rotation process part cooperate and perform the transfer process and rotation process of image data. It is a flowchart which shows the flow of the cooperation rotation process by the host CPU side. It is a flowchart which shows the flow of the cooperation rotation process by the rotation process part side. It is a sequence diagram which shows the flow of the cooperation rotation process of host CPU and a rotation process part. It is a block diagram which shows the principal part structure of the conventional image display system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper housing | casing 1a Display part 2 Lower housing | casing 2a Operation part 3 Hinge part 100 Liquid crystal display device 110 Liquid crystal panel 120 Liquid crystal driver 200 Liquid crystal controller (display control apparatus)
210 RAM (memory)
220 Read unit 230 Synchronization control unit 240 Host IF (write unit)
250 Rotation processing unit 251 CPU
252 Bus IF
253 Local RAM
254 DMA controller (copying means)
260 Interrupt processing unit 270 Status notification unit 300 Display data generation device 310 Host CPU
320 RAM

Claims (10)

A display device capable of rotating a display unit for displaying an image, a display control device for reading necessary display image data from a memory storing the display image data and transferring the display image data to the display unit, and the display image data In an image display system including a display image data generation device that generates and transfers to the display control device,
The display control device
A write unit for writing the display image data transferred from the display image data generation device into the memory;
A rotation processing unit that performs rotation processing on the display image data on the memory,
The write unit is controlled to write the display image data transferred from the display image data generation device to the memory at the start timing of the display image data rotation process by the rotation processing unit. Image display system. The display control device
The write unit causes the display image data generated by the display image data generation device to be written to the memory in units of a plurality of lines.
The image display system according to claim 1, wherein the rotation processing unit rotates display image data in the order written in the memory.   3. The image display system according to claim 1, wherein the display data storage area of the memory has a double buffer configuration. The display control device
A read unit that reads display image data stored in the memory and transfers the display image data to the display device according to a synchronization signal at a predetermined timing by the synchronization control unit;
Copy means for collectively copying the display image data rotated by the rotation processing unit to the display image data storage area read by the read unit of the memory in the same direction as the scanning direction read by the read unit; The image display system according to claim 1, further comprising: an image display system according to claim 1. The rotation processing unit
CPU and local RAM
A part or all of the display image data written in the memory is transferred to the local RAM, the display image data transferred to the local RAM is rotated by the CPU, and the display data is rotated. The image display system according to any one of claims 1 to 4, wherein the image data is written in an area where the read unit of the memory reads data.   An information device comprising the image display system according to any one of claims 1 to 5. In a display control device that includes a memory that stores display image data captured from the outside, and that reads necessary display image data from the memory that stores display image data and transfers the display image data to the display unit.
A write unit for writing display image data captured from outside to the memory;
A rotation processing unit that performs rotation processing on the display image data on the memory,
A display control apparatus, wherein the write unit is controlled to write display image data fetched from outside into the memory at a start timing of rotation processing of display image data by the rotation processing unit. In a display control method of reading out necessary display image data from a storage memory and transferring the display image data captured from outside to a display unit,
A data writing step of writing display image data captured from the outside into the memory;
A rotation processing step for performing rotation processing on the display image data on the memory,
A display control method, wherein the data writing step is executed at a timing when the rotation processing step is executed.   A display control program for causing a computer to function as each unit of the display control device according to claim 7.   A computer-readable recording medium on which the display control program according to claim 9 is recorded.

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