JP2008090080A - Display controller, display system, and display control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a plurality of display devices to synchronously display images even when there are differences in communication time and processing capability for image data when an image is displayed on a large screen constituted by using the plurality of display devices. <P>SOLUTION: A multi-display control unit 23 transmits a probe packet 90 containing reference image data to display units 25 to 28. The display units 25 to 28 respectively add reception time information on the probe packet 90 and display processing completion time information on the reference image data to the probe packet 90 and send them back to the multi-display control unit 23. The multi-display control unit 23 once receiving sent-back probe packets 90 finds times of communication with the respective display units 25 to 28 and display processing times of the respective display units 25 to 28. Then a transmission schedule for image data packets 50 is determined based upon them. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a display control device, a display system, and a display control method, and is particularly suitable for use in displaying a single screen by combining a plurality of display devices.

  2. Description of the Related Art Conventionally, a commercial multi-screen display device is known as a display system that combines a plurality of display units to form a large screen and displays an image on the large screen. This business-use multi-screen display device is realized for applications such as a super-large screen display device installed on the rooftop of a building, and displays various moving images such as corporate advertisements. Here, the method of constructing a large screen is roughly divided into a method of directly spreading pixels and a method of combining a plurality of display units described above.

A method for combining a plurality of display units will be further described.
The display panel is configured by stacking a plurality of display units of various types such as a projector and a CRT (Cathode Ray Tube) adjacent to each other. The video content data is divided into images for each display area of each display unit after development. Thereby, display data of each display unit is generated. The generation of display data may be performed by providing a multi-display server or in each display unit.

  First, a case where display data is generated by a multi-display server will be described. The multi-display server is connected to a video content supply device and also connected to a plurality of display units. The video content data input from the supply device is developed in the multi-display server, divided into images for each display unit, and transmitted to the display unit responsible for each display. Each display unit can display a very large screen simply by displaying the received data as it is.

  Next, a case where display data is generated in each display unit will be described. Each display unit inputs video content data, and cuts out the input data according to the display charge area. Thereafter, processing such as enlargement / reduction in accordance with the resolution of the display panel is performed on the cut-out data, and display is performed. As a configuration for generating display data in each display unit in this way, a configuration in which the server device performs decompression from the compressed data, and a configuration in which the server device generates and issues a control processing command. Various configurations have been proposed.

  In this way, when a plurality of display units are combined, a large screen is configured using a plurality of display units, and images are displayed on the large screens, the images are corrupted unless the display units are synchronized. End up. It becomes difficult to synchronize between display units due to a difference in processing capability between display units and a difference in the size of screen data to be displayed. Conventional methods for synchronizing display units include the following.

  First, there is a technique described in Patent Document 1. In this technology, the amount of video data is changed in accordance with the display unit having the slowest video processing performance. Then, the video data with the changed video data amount is transmitted to each display unit, and the display units are synchronized with each other.

  Further, there is a technique described in Patent Document 2. In this technique, a moving image is reproduced to measure a moving image display speed, and actual reproduction speed data that can be displayed on each display unit is calculated based on the moving image display speed. Each display unit displays the image data in the memory based on the reproduction speed data, thereby synchronizing the display between the display units.

JP 2003-44029 A JP 2005-86592 A

  However, in the technique described in Patent Document 1, in order to synchronize the display between the display units, the display timing of each display unit is determined in consideration of only the display processing capability of each display unit. Therefore, when there is a difference in the communication time of the image data between the transmission source of the image data and each display unit or between each display unit, there is the following problem. That is, in a display unit that requires a long communication time of image data, the image data to be displayed has not arrived or the display process has not been completed even when the display timing determined to be synchronized can be reached. There was a problem.

  Further, in the technique described in Patent Document 2, each display unit stores image data to be displayed in a memory, and reads and displays the image data from the memory at a timing based on the reproduction speed data. Therefore, when there is a large difference between the processing capacities of the display units, there is the following problem when synchronizing with the display unit having the slowest processing capacity. That is, there is a problem in that the memory of the display unit waiting for display due to a display unit with a slow processing capacity becomes insufficient due to image data received while waiting for display.

  The present invention has been made in view of such problems, and there is a difference in communication time and processing capability of image data when an image is displayed on a large screen configured using a plurality of display devices. However, it is an object to enable a plurality of display devices to display images in synchronization.

A display control apparatus according to the present invention is a display control apparatus that performs control for displaying data of image content on a plurality of display devices that constitute one display screen, and is configured to display image content that is a display target in the display device. Temporary image data transmitting means for transmitting transmission data including reference image data corresponding to the data and information indicating a display device that is an image display destination based on the reference image data to the display device; and the temporary image data Reply data based on the transmission data sent by the sending means, receiving means for receiving from the display device, and communication time to each of the plurality of display devices based on the reply data received by the receiving means, And a time deriving unit for obtaining display processing times in the plurality of display devices.
The display device of the present invention is a display device that constitutes a part of one display screen, and includes reference image data corresponding to image content data to be displayed, and an image display destination based on the reference image data. Receiving means for receiving transmission data including information indicating the display device, from a display control device that performs control for displaying the data of the image content, and a display device that is a display destination of an image based on the reference image data When the transmission data received by the receiving means includes information indicating that the display device is its own display device, the display processing means performs display processing of the reference image data, and the display processing means Information regarding the time when the display processing of the reference image data is completed and reception time information regarding the time when the transmission data including the reference image data is received are included. And having a returning means for returning the reply data to the display control device.

  The display control method of the present invention includes reference image data corresponding to image content data to be displayed on a display screen constituted by a plurality of display devices, and a display device serving as a display destination of an image based on the reference image data. A temporary image data transmission step of transmitting transmission data including information indicating the transmission data to the display device, a transmission data reception step of receiving the transmission data transmitted by the temporary image data transmission step, and the reference If the transmission data received by the receiving step includes information indicating that the display device that is the display destination of the image based on the image data is its own display device, the reference image data is displayed. A display processing step to be performed; information relating to a time at which the display processing of the reference image data is completed by the display processing step; A reply step of returning reply data including reception time information relating to a time at which transmission data including the reference image data is received; a reception step of receiving reply data returned by the reply step from the display device; And a time deriving step for obtaining a communication time to each of the plurality of display devices and a display processing time in the plurality of display devices based on the reply data received in the receiving step.

The computer program of the present invention is a computer program that causes a computer to execute control for displaying data of image content on a plurality of display devices that constitute one display screen, and is to be displayed on the display screen. A temporary image data transmission step of transmitting transmission data including reference image data corresponding to image content data and information indicating a display device that is an image display destination based on the reference image data to the display device; And receiving the reply data based on the transmission data transmitted in the provisional image data transmission step from the display device, and each of the plurality of display devices based on the reply data received in the reception step. For determining the communication time of the display and the display processing time of the plurality of display devices. Characterized in that to perform the steps on a computer.
Another feature of the present invention is a computer program for causing a computer to display an image on a display device that constitutes a part of one display screen, the image content data to be displayed. A receiving step of receiving transmission data including reference image data corresponding to the information and information indicating a display device that is an image display destination based on the reference image data; and a display device that is an image display destination based on the reference image data. When information indicating that the display device is its own is included in the transmission data received in the reception step, a display processing step for performing display processing of the reference image data, and the reference processing step performs the reference processing step. Information about the time when the display processing of image data was completed and the time when the transmission data including the reference image data was received. Characterized in that to execute a return step for returning the reply data including the received time information that the computer.

  According to the present invention, even if there is a difference in communication time and processing capability of image data, a plurality of display devices can display images in synchronization.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating an example of the overall schematic configuration of a multi-display system.
In FIG. 1, the multi-display system 21 receives image content data from the content server 20 and displays it. The display is performed on a screen in which display units (Disp0 to Disp4) 25 to 28 of 2 rows × 2 columns are combined. Note that the display units (Disp0 to Disp4) 25 to 28 of 2 rows × 2 columns are connected to each other by a daisy chain as shown in FIG.

  In response to a request from a client (for example, a client terminal device not shown), the content server 20 distributes the image content data to the multi-display control unit 23 which is an example of a display control device. The distributed image content data is encoded by, for example, the content server 20 in order to reduce the communication band. That is, the original image content data is MPEG, MPEG2, or H.264. It is compressed by an encoding method such as H.264. The compressed image content data is converted into a transport stream of a format such as MPEG2-TS and transmitted. Any encoding method or stream method can be used.

  The multi-display system 21 receives image content data streamed from the content server 20 and displays an image based on the received image content data. The communication line 22 is used to transmit data of image content that is streamed. As the communication line 22, various systems such as a network such as the Internet or an interface between devices such as IEEE1394 can be used.

  In the multi-display system 21, the multi-display control unit 23 supplies image content data to the display units 25 to 28. The communication path 24 is a communication path for supplying image content data to the display units 25 to 28. The communication path 24 is configured by a network such as a LAN (Local Area Network), a WAN (Wide Area Network), or the Internet, for example.

  The display units 25 to 28 receive supply of image content data from the multi-display control unit 23. Each of the display units 25 to 28 displays a part of the image content based on the image content data belonging to its own display area. As each of the display units 25 to 28, various types of display panels can be used. For example, the display units 25 to 28 may be SED (Surface-conduction Electron-emitter Display), LCD (Liquid Crystal Display), or plasma display. Note that at least one of the display units 25 to 28 may be a display panel of a different type from the other display units. By increasing the display surface of the display units 25 to 28 or increasing the number of display units to be combined, display with a larger screen size becomes possible.

  There are various methods for setting the display charge areas of the display units 25 to 28, and any method can be used. As the simplest method, there is a method in which the user explicitly sets it. When a user operates a switch or the like provided in each of the display units 25 to 28, a display area in charge of the display unit provided with the switch can be set. In addition, information for instructing the display area in charge of the display units 25 to 28 is transmitted from, for example, the client terminal device to the multi-display control unit 23, and the multi-display control unit 23 displays the display charge areas in the display units 25 to 28. May be set.

  Moreover, the display units 25-28 can be attached to a frame-shaped guide member. The user fits the display units 25 to 28 into a guide member that can support the display units 25 to 28 arranged in 2 × 2 (2 rows and 2 columns). Further, the user connects a power source and a signal line to these display units 25 to 28. Thereby, the large screen by the display units 25-28 is comprised. By assigning unique identifiers to the display units 25 to 28 according to the mounting positions of the display units 25 to 28, identification of the display units 25 to 28 and identification of the positions of the display units 25 to 28 can be performed. Yes. Further, a sensor may be provided on the coupling surface of each display unit 25 to 28 so that the position of each display unit 25 to 28 can be specified from the detection result of the sensor. For example, sensors are provided in four directions (for example, an upper surface, a lower surface, and both side surfaces) where the display units 71 to 79 can be coupled. When the display units 25 to 28 are coupled, each display unit 25 to 28 exchanges an ID with a coupling partner using a sensor. In this way, the positions of the display units 25 to 28 can be specified by counting the IDs held by the display units 25 to 28.

  FIG. 2 is a diagram illustrating an example of a configuration of a probe packet having the multi-display control unit 23 as a transmission source. By the probe packet, the multi-display control unit 23 can grasp the time from when the multi-display control unit 23 transmits the image content data until the image content data reaches the display units 25 to 28. The multi-display control unit 23 can grasp the time from when the display units 25 to 28 receive the image content data until the display processing of the image content data is completed by the probe packet. In the following description, the time from when the multi-display control unit 23 transmits image content data to when the image content data reaches the display units 25 to 28 is referred to as communication time as necessary. The time from when the display units 25 to 28 receive the image content data until the display processing of the image content data is completed is referred to as display processing time as necessary.

  FIG. 2A shows the probe packet 90. FIG. 2B is a diagram illustrating the configuration of the probe packet 90. As shown in FIG. 2B, the probe packet 90 has a header 91 and a payload 92. The payload 92 stores reference image data. The reference image data is data used in place of the image content data used for actual display so that the multi-display control unit 23 can grasp the communication time and the display processing time. As described above, the reference image data is data corresponding to the image content data used for actual display, for example, the data amount and the data format.

  FIG. 2C shows the configuration of the header 91. The packet identification information section 93 indicates the type of packet. The packet identification information section 93 stores ID information for identifying whether or not the packet to which the packet belongs is a probe packet 90, version information, and the like. Further, information necessary for packet processing such as packet length and checksum may be stored in the packet identification information section 93.

  The transmission destination ID section 94 stores transmission destination ID information for designating a display unit that is the destination of the probe packet 90. By setting a specific value as the transmission destination ID information, the probe packet 90 can be broadcast to all the display units. The attribute data section 95 stores various attribute data necessary for image data processing.

  FIG. 2D shows a configuration of the probe packet 90 to which a time stamp is added. The transmission time portion 96 stores transmission time information indicating the time when the probe packet 90 is transmitted. The screen ID portion 97 stores screen ID information indicating a display unit to which a time stamp is added. In the arrival time section 98, reception time information indicating the time when the display unit receives the probe packet 90 is stored. The process completion time section 99 stores display process completion time information indicating the time when the display unit has completed the display process.

Here, an example of a method for adding a time stamp to the probe packet 90 will be described. FIG. 3 is a time chart (FIG. 3A) for explaining an example of the operation of the display units 25 to 28 when adding a time stamp to the probe packet 90, and an example of the probe packet with the time stamp added (FIG. 3). 3 (b)).
In FIG. 3A, it is assumed that the probe packet 90 arrives at the display unit 25 at time 601. Assume that the display unit 25 completes the display process at time 602. Similarly, it is assumed that the probe packet 90 arrives at the display units 26 to 28 at times 603, 605, and 607, respectively. Then, it is assumed that the display units 26 to 28 complete the display process at times 604, 606, and 608, respectively.

  In each display unit 25-28, reception time information indicating times 601, 603, 605, and 607 and display processing completion time information indicating times 602, 604, 606, and 608 are added to the probe packet 90. The probe packet 90 is time stamped in the order of the display unit 25, the display unit 26, the display unit 27, and the display unit 28, respectively. Finally, as shown in FIG. 3B, a probe packet 90 to which identification information (screen ID information) of each display unit 25 to 28 to which a time stamp is added is also transmitted to the multi-display control unit 23. The Details of FIG. 3B will be described later.

  FIG. 4 is a diagram showing an example of the configuration of the image data packet in the present embodiment. FIG. 4A shows an image data packet 50. FIG. 4B is a diagram illustrating the configuration of the image data packet 50. As shown in FIG. 4B, the image data packet 50 has a header 51 and a payload 52. The payload 52 stores image content data. In the following description, image content data and reference image data are collectively referred to as image data as necessary.

FIG. 4C is a diagram illustrating the configuration of the header 51. The packet identification information unit 53 indicates the type of packet. The packet identification information section 53 stores ID information for identifying whether the packet to which the packet belongs is an image data packet 50, version information, or the like. Further, information necessary for packet processing such as a packet length and a checksum may be stored in the packet identification information unit 53.
The transmission destination ID section 54 stores transmission destination ID information for designating a display unit that is the destination of the image data packet 50. By setting a specific value as the destination ID information, the image data packet 50 can be broadcast to all the display units. The attribute data section 55 stores various attribute data necessary for image data processing. The display scheduled time section 56 stores display time information indicating the time when the display unit performs display.

FIG. 5 is a diagram illustrating an example of the configuration of the multi-display control unit 23.
In FIG. 5, the multi-display overall control unit 23 controls the entire multi-display system. The multi-display overall control unit 23 includes, for example, a CPU, a memory such as a ROM and a RAM, a bus, various interfaces, and the like. The CPU executes the program recorded in the ROM by using the RAM or the like, thereby controlling the entire multi-display system.

  The server interface (server I / F) 62 inputs image content data from the content server 20 via the communication line 22. Data transmitted from the content server 20 is encoded (compressed) in order to reduce the communication band, converted into a transport stream, and transmitted. The expansion / image processing unit 63 expands the transport stream data that has been compressed and transmitted, and performs various types of image processing to improve image quality. Here, for the expansion of the compression format, MPEG, MPEG2, MPEG4, and H.264 are used. Various systems such as H.264 can be used. The image processing includes, for example, processing for correcting various distortions and deterioration, edge enhancement processing, color correction processing, and the like. Further, the expansion / image processing unit 63 determines reference image data to be stored in the probe packet 90 from image data obtained by expanding the transport stream data.

The data division unit 64 divides the image data according to the number of display units 25 to 28 and the shape configured by combining the display units 25 to 28.
The encoder unit 65 synchronizes the image data divided by the data dividing unit 64 for each division unit in order to convert the image data divided by the data dividing unit 64 into a size that can be transmitted via the communication path 24. Compression is performed at a bit rate specified by the control unit 66.

  The synchronization control unit 66 determines the bit rate of the encoder unit 65 based on the communication time to each of the display units 25 to 28 and the display processing time of each of the display units 25 to 28. The communication time and the display processing time are obtained by transmitting the probe packet 90 to the display units 25 to 28. Further, the synchronization control unit 66 determines the scheduled display time at which the image content data is displayed on the display units 25 to 28 and performs scheduling when packets are transmitted to the display units 25 to 28. Further, the synchronization control unit 66 generates transmission destination ID information for designating a display unit that receives the image data packet 50.

The probe packet generator 67 generates a probe packet 90 having the structure shown in FIG.
The data packet generator 68 generates the image data packet 50 having the structure shown in FIG. The data packet generator 68 adds header information to the encoded image content data to packetize it. The header 51 stores packet identification information, transmission destination ID information indicating a display unit that is the transmission destination of the image data packet 50, display time information, and the like.

  The time measuring unit 69 obtains the next time based on the time stamp added to the probe packet 90 returned from the display units 25 to 28. That is, the time measuring unit 69 obtains the communication time from the multi-display control unit 23 to each display unit 25 to 28 and the display processing time of each display unit 25 to 28 based on the time stamp.

  The transmission / reception interface (transmission / reception I / F) 60 transmits the probe packet 90, the image data packet 50, and the like to the display units 25-28. The probe packet 90 and the image data packet 50 are broadcast to the display units 25 to 28 interconnected with the multi-display control unit 23. The transmission / reception interface 60 also transmits / receives various control data created by the multi-display overall control unit 61 to / from the display units 25 to 28 separately.

  FIG. 6 is a diagram illustrating an example of the configuration of the display units 25 to 28. Since the configurations of the display units 25 to 28 are the same, only the configuration of the display unit 25 will be described here, and the description of the configurations of the other display units 26 to 28 will be omitted.

  In FIG. 6, the display unit overall control unit 71 controls each element constituting the display unit 25. The display unit overall control unit 71 includes, for example, a CPU, a memory such as a ROM and a RAM, a bus, various interfaces, and the like. The CPU performs overall control by executing a program recorded in the ROM by using the RAM.

  The transmission / reception interface (transmission / reception I / F) 72 performs transmission / reception between the probe packet 90 and the image data packet 50. The transmission / reception interface (transmission / reception I / F) 72 also transmits and receives control data and the like sent from the multi-display overall control unit 61.

  The packet analysis / identification unit 73 analyzes the headers 91 and 51 of the arrived probe packet 90 and the image data packet 50, and determines whether the arrived probe packet 90 and the image data packet 50 are in charge of itself. The packet analysis / identification unit 73 identifies whether the arrived packet is the probe packet 90 or the image data packet 50.

  The probe packet control unit 74 adds screen ID information indicating the display unit 25 to the probe packet 90. Further, the probe packet control unit 74 adds reception time information indicating the time when the probe packet 90 arrives at the display unit 25 to the probe packet 90 as a time stamp. Further, the probe packet control unit 74 adds display processing completion time information indicating the time when the display unit 25 has completed the display processing of the image data included in the probe packet 90 to the probe packet 90 as a time stamp. Further, the probe packet control unit 74 transmits the probe packet 90 to which a time stamp or the like is added based on the transmission destination ID information stored in the transmission destination ID unit 94 in the header 91 of the probe packet 90.

  When the data packet transmission unit 70 receives the image data packet 50, the data packet transmission unit 70 determines the transmission destination of the image data packet 50 based on the transmission destination ID information stored in the transmission destination ID unit 54 of the header 51 of the image data packet. An image data packet 50 is transmitted.

The decoder unit 75 decodes the image data encoded by the multi-display control unit 23.
The image processing unit 76 performs various types of necessary image processing, image processing depending on the display panel 79, and the like on the image data decoded by the decoder unit 75.

  The display control unit 77 performs drive control of the display panel 78. For example, the display control unit 77 outputs image data to the display panel 79 in synchronization with a driving signal such as a horizontal synchronizing signal / vertical synchronizing signal or a data transfer clock. The image data is stored in a memory such as a VRAM (not shown), read out in synchronization with the drive signal timing, and output to the display panel 79.

  The synchronization control unit 78 controls the display control unit 77 to display the image data at the scheduled display processing completion time (stored in the processing completion time unit 99) added to the received probe packet 90.

  The display panel 79 displays the image data of its own display area. As the display panel 78, as described above, any type of display device such as an SED, LCD, plasma display, or projection display can be used.

  Next, an example of a processing operation for the probe packet 90 in the multi-display control unit 23 will be described with reference to the flowchart of FIG. Here, the case where the multi-display control unit 23 receives image data compressed by MPEG from the content server 20 as image content data will be described as an example.

  Prior to transmitting image content data to each of the display units 25 to 28, the multi-display control unit 23 of the present embodiment acquires the following information. That is, the multi-display control unit 23 acquires the communication time of the reference image data from the display units 25 to 28 and the display processing time of the reference image data in the multi-display units 25 to 28. For this purpose, the multi-display control unit 23 transmits a probe packet 90 to the display units 25 to 28.

(Step S101)
The development / image processing unit 63 determines reference image data. In the present embodiment, image data (MPEG data) compressed by MPEG of about 10 samples is received from the content server 20 in order to determine reference image data. The development / image processing unit 63 selects MPEG data having the maximum data size as reference image data as data that takes the longest time to process among the MPEG data.

(Step S102)
Next, the development / image processing unit 63 develops the reference image data selected in step S101, and performs image processing on the developed reference image data. Examples of image processing include processing for correcting various distortions and deterioration, edge enhancement processing, color correction processing, and the like.

(Step S103)
The data dividing unit 64 divides the reference image data subjected to image processing in step S102 according to the number of display units 25 to 28 and the shape configured by combining the display units 25 to 28.

(Step S104)
The encoder unit 65 compresses the reference image data divided in step S103, for example, in the Motion JPEG format using the bit rate of the header of the MPEG data as the reference bit rate.

(Step S105)
The probe packet generator 67 generates a probe packet 90. Specifically, the probe packet generation unit 67 stores the reference image data compressed in step S104 as the payload 92 of the probe packet 90. The probe packet generator 67 stores ID information indicating the probe packet 90 in the packet identification information unit 98. The probe packet generation unit 67 stores the transmission destination ID information (broadcast value) in the transmission destination ID unit 94. The probe packet generation unit 67 stores the attribute data in the attribute data unit 95. Subsequently, the probe packet generation unit 67 adds transmission time information indicating the time when the probe packet 90 was transmitted to the probe packet 90 as a time stamp (stores in the transmission time unit 96), and displays the display units 25 to 28. Send to.

(Step S106)
When the probe packet 90 is transmitted in step S105, the multi-display control unit 23 stands by until the probe packet 90 is returned from the display unit 28. When the probe packet 90 is returned from the display unit 28, the time measuring unit 69 receives the probe packet 90 from the transmission / reception interface 60.

(Step S107)
Upon receiving the probe packet 90 received in step S106, the time measuring unit 69 obtains the next time based on the time stamp added to the probe packet 90. That is, the time measuring unit 69 obtains the communication time from the multi-display control unit 23 to each display unit 25 to 28 and the display processing time of each display unit 25 to 28 based on the time stamp.

Here, an example of the time calculation method of the time measurement unit 69 in this embodiment will be described with reference to FIG.
When the time measuring unit 69 receives the probe packet 90 as shown in FIG. 3B, the time measuring unit 69 acquires the following time stamp information 801 to 813 stored following the payload 92. The time stamp information 801 is the transmission time of the probe packet 90 in the multi-display control unit 23.

  The time stamp information 802 is screen ID information indicating the display unit 25. The time stamp information 803 is reception time information of the probe packet 90 in the display unit 25. The time stamp information 804 is display processing completion time information in the display unit 25.

The time stamp information 805 is screen ID information indicating the display unit 26. The time stamp information 806 is reception time information of the probe packet 90 in the display unit 26. The time stamp information 807 is display processing completion time information in the display unit 26.
The time stamp information 808 is screen ID information indicating the display unit 27. The time stamp information 809 is reception time information of the probe packet 90 in the display unit 27. The time stamp information 810 is display processing completion time information in the display unit 27.

  The time stamp information 811 is screen ID information indicating the display unit 28. The time stamp information 812 is reception time information of the probe packet 90 in the display unit 28. The time stamp information 813 is display processing completion time information in the display unit 28.

The time measurement unit 69 includes reception time information 803, 806, 809, 812 added after the screen ID information 802, 805, 808, 811 indicating the display units 25-28 and display processing completion times 804, 807, 810. , 813 and the following calculation is performed.
First, the time measuring unit 69 obtains the communication time to the display unit 25. In the example shown in FIG. 3B, the communication time to the display unit 25 is 3 [ms] (= 3-0).
Further, the time measuring unit 69 obtains the display processing time in the display unit 25. In the example shown in FIG. 3B, the display processing time in the display unit 25 is 5 [ms] (= 8-3).

Secondly, the time measuring unit 69 obtains the communication time to the display unit 26. In the example shown in FIG. 3B, the communication time to the display unit 26 is 5 [ms] (= (10−8) +3).
Further, the time measuring unit 69 obtains the display processing time in the display unit 26. In the example shown in FIG. 3B, the display processing time in the display unit 26 is 5 [ms] (= 15-10).

Thirdly, the time measuring unit 69 obtains the communication time to the display unit 27. In the example shown in FIG. 3B, the communication time to the display unit 27 is 7 [ms] (= (17−15) +5).
Further, the time measuring unit 69 obtains the display processing time in the display unit 27. In the example shown in FIG. 3B, the display processing time in the display unit 27 is 5 [ms] (= 22-17).

Fourth, the time measurement unit 69 obtains the communication time to the display unit 28. In the example shown in FIG. 3B, the communication time to the display unit 28 is 9 [ms] (= (24-22) +7).
Further, the time measuring unit 69 obtains the display processing time in the display unit 28. In the example shown in FIG. 3B, the display processing time in the display unit 28 is 5 [ms] (= 29-24).

Next, an example of a processing operation for the image data packet 50 in the multi-display control unit 23 will be described with reference to the flowchart of FIG.
When the transmission process of the probe packet 90 is completed, the multi-display control unit 23 of the present embodiment starts transmitting the image data packet 50 to each display unit 25-28.

(Step S201)
When the server interface 62 receives MPEG-compressed image data as image content data, the expansion / image processing unit 63 expands the image content data and performs necessary image processing on the expanded image data. Do.

(Step S202)
The data dividing unit 64 divides the data of the image content subjected to the image processing in step S201 according to the number of display units 25 to 28 and the shape configured by combining the display units 25 to 28.

(Step S203)
Subsequently, the synchronization control unit 66 acquires the data of the image content divided in step S202 from the data dividing unit 64. Then, the synchronization control unit 66 compares the divided image data with the reference image data determined in step S101 in FIG. Then, the synchronization control unit 66 calculates the bit rate of the encoder unit 65 so that the size obtained by compressing the data of the divided image content is equal to the size obtained by compressing the reference image data.

(Step S204)
The encoder unit 65 encodes the image content data divided in step S202 in accordance with the bit rate determined in step S203, and supplies the encoded image content data to the data packet generation unit 68.

(Step S205)
Based on a timer (not shown), the synchronization control unit 66 obtains the scheduled display time at which the image content data is displayed on the display units 25 to 28, and supplies the obtained scheduled display time to the data packet generation unit 68. Further, the synchronization control unit 66 generates transmission destination ID information for designating a display unit that receives the image data packet 50, and supplies the generated transmission destination ID information to the data packet generation unit 68.

(Step S206)
The data packet generation unit 68 includes image content data supplied from the encoder unit 65, various attribute data necessary for processing the image content data, transmission destination ID information supplied from the synchronization control unit 66, and display schedule. Get time and. Then, the data packet generator 68 generates the image data packet 50 by collecting the acquired information together with the packet identification information and the like.

(Step S207)
The synchronization control unit 66 adjusts the transmission schedule of the image data packet 50 based on the communication time from the multi-display control unit 23 to each display unit 25-28 and the display processing time of each display unit 25-28. . Note that the communication time from the multi-display control unit 23 to each of the display units 25 to 28 and the display processing time of each of the display units 25 to 28 are obtained by the time measuring unit 69 in step S107 of FIG.

Here, an example of a method for adjusting the transmission schedule of the image data packet 50 will be described. FIG. 9 is a diagram illustrating an example of a transmission schedule of the image data packet 50.
In FIG. 9, time 701 is a communication time from the multi-display control unit 23 to the display unit 25. Time 702 is a communication time from the multi-display control unit 23 to the display unit 26. Time 703 is a communication time from the multi-display control unit 23 to the display unit 27. A time 704 is a communication time from the multi-display control unit 23 to the display unit 28. Time 705 is display processing time in each display unit 25-28.

First, the synchronization control unit 66 performs the following processing based on the communication time and display processing time of each display unit 25-28. That is, the synchronization control unit 66 calculates a necessary time from when the multi-display control unit 23 transmits the image data packet 50 to when the display processing based on the image data packet 50 is completed in each display unit 25-28. To do. In the example shown in FIG. 9, it is calculated as follows.
The necessary time required for the display unit 25 to display the amount of image data is 8 [ms] (= 3 + 5).
The necessary time required for the display unit 26 to display the amount of image data is 10 [ms] (= 5 + 5).
The necessary time required for the display unit 27 to display the portion for image data is 12 [ms] (= 7 + 5).
The necessary time required for the display unit 28 to display the amount of image data is 14 [ms] (= 12 + 5).

  Then, the synchronization control unit 66 determines the transmission order of the image data packet 50 as the display unit 28, the display unit 27, the display unit 26, and the display unit 25 from the magnitude of the required time calculated as described above. . Furthermore, the synchronization control unit 66 transmits the image data packet 50 to each of the display units 25 to 28 at an optimum timing with respect to the scheduled display time 1/60 [sec] from the necessary time calculated as described above. Packet transmission command is generated.

(Step S208)
The data packet generator 68 adds information such as a transmission time as a time stamp to the image data packet 50 generated in step S206. Then, the data packet generator 68 transmits the image data packet 50 to the display units 25 to 28 via the transmission / reception interface 60 in accordance with the packet transmission command generated in step S207.

  Next, an example of processing operations for packets in the display units 25 to 28 will be described with reference to the flowchart of FIG.

(Step S301)
When the transmission / reception interface 72 receives a packet such as the probe packet 90 or the image data packet 50 from the multi-display control unit 23, the packet analysis / identification unit 73 analyzes the headers 51 and 91 of the received packet.

(Step S302)
Based on the transmission destination ID information stored in the transmission destination ID sections 54 and 94 of the headers 51 and 91 of the received packet, the packet analysis / identification unit 73 determines whether or not the received packet is for itself. Determine. If the result of this determination is that the received packet is not its own charge, the packet analysis / identification unit 73 outputs the packet to the data packet control unit 70. And it progresses to step S307 mentioned later. On the other hand, if the received packet is for itself, the process proceeds to step S303.

(Step S303)
The packet analysis / identification unit 73 determines whether the received packet is the probe packet 90 or the image data packet 50 based on the ID information stored in the packet identification information units 53 and 93 of the headers 51 and 91 of the received packet. Determine if there is. As a result of the determination, if the received packet is the image data packet 50, the process proceeds to step S308 described later. On the other hand, if the received packet is the probe packet 90, the process proceeds to step S304.

(Step S304)
The probe packet control unit 74 receives the probe packet 90, and adds the screen ID information of its own display unit and reception time information indicating the time when the probe packet 90 is received to the probe packet 90.

(Step S305)
The decoder unit 75 expands and decodes the reference image data stored in the payload 52 of the received probe packet 90 in, for example, the Motion JPEG format. Then, the image processing unit 76 performs necessary image processing on the decoded reference image data, and outputs display processing completion time information indicating the time when the image processing is completed to the probe packet control unit 74.

(Step S306)
The probe packet control unit 74 adds the display processing completion time information output from the image processing unit 76 in step S305 to the probe packet 90.
(Step S307)
The probe packet transmission unit 74 displays the probe packet 90 to which reception time information, display processing completion time information, and the like are added, from the display units 25 to 28 indicated by the transmission destination ID information stored in the header 91 or the multi-display control unit 23. Send to.

  In step S302, when the received packet is input to the data packet control unit 70 (when the received packet is not a packet for its own charge), the following processing is performed in step S307. That is, the data packet control unit 70 transmits the received packet to the display unit or the multi-display control unit 23 indicated by the transmission destination ID information stored in the headers 51 and 91 of the received packet.

(Step S308)
In step S303, when the received packet is the image data packet 50, the process proceeds to step S308. Then, the decoder unit 75 develops and decodes the image content data stored in the received image data packet 50 in, for example, the Motion JPEG format. Then, the image processing unit 76 performs necessary image processing on the decoded image content data, and outputs the image content data subjected to the image processing to the display control unit 77.

(Step S309)
The synchronization control unit 78 sets the display control unit 77 at the scheduled display time based on the scheduled display time information stored in the header 51 (the scheduled display time unit 56) of the received image data packet 50 and a timer (not shown). A command necessary for displaying image content data is generated.
(Step S310)
The display control unit 77 displays the data of the image content that has been subjected to image processing by the image processing unit 76 on the display panel 79 in accordance with the command generated by the synchronization control unit 78 in step S209.

  As described above, in the present embodiment, the multi-display control unit 23 transmits the probe packet 90 including the reference image data to the display units 25 to 28. The display units 25 to 28 add the reception time information of the probe packet 90 and the display processing completion time information of the reference image data to the probe packet 90 as a time stamp and send it back to the multi-display control unit 23. When the multi-display control unit 23 receives the reply of the probe packet 90 with the time stamp added, the multi-display control unit 23 calculates the communication time to each of the display units 25 to 28 and the display processing time of each of the display units 25 to 28 based on the time stamp. Ask. Then, the multi-display control unit 23 obtains the time required for each display unit 25 to 28 to display the assigned portion of the image data based on the obtained communication time and display processing time. Determine the transmission order. Finally, the multi-display control unit 23 transmits the image data packet 50 to the display units 25 to 28 based on the determined transmission order.

  As described above, in this embodiment, the actual communication time from the multi-display control unit 23 to the display units 25 to 28 and the display processing time in the display units 25 to 28 are acquired, and the transmission schedule of the image data packet 50 is acquired. To decide. Therefore, even if there is a difference in the processing capability of the display units 25 to 28 or a difference in the communication path connecting the multi-display control unit 23 and the display units 25 to 28, the display units 25 to 28 are synchronized. Image data can be displayed. Further, the multi-display control unit 23 that is the transmission source of the image data packet 50 adjusts the transmission schedule of the image data packet 50. Accordingly, the display units 25 to 28 can display images in synchronization between the display units 25 to 28 without having a large memory.

  In the present embodiment, the case where the screen is configured by combining the display units 25 to 28 of 2 rows × 2 columns has been described as an example, but the number and arrangement of the display units are not limited to this.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the first embodiment described above, a multi-display system configured by connecting a plurality of display units 25 to 28 in a daisy chain has been described. In the present embodiment, a multi-display system having a configuration in which a multi-display control unit and each display unit are directly connected will be described. As described above, the present embodiment and the first embodiment described above are mainly different in the connection form between the multi-display control unit, each display unit, and each display unit. Therefore, in the description of the present embodiment, the same parts as those in the first embodiment described above are denoted by the same reference numerals as those in FIGS.

FIG. 11 is a diagram illustrating an example of an overall schematic configuration of a multi-display system.
Similarly to the first embodiment, the multi-display system 41 of the present embodiment also receives image content data from the content server 20 and displays it. The display is performed on a screen in which display units (Disp0 to Disp4) 45 to 48 of 2 rows × 2 columns are combined. Note that the display units (Disp0 to Disp4) 45 to 48 of 2 rows × 2 columns are connected to each other as shown in FIG.

  In FIG. 11, the content server 20 performs streaming distribution of image content data to the multi-display control unit 41 in response to a request from a client (for example, a client terminal device not shown). The multi-display system 41 receives image content data streamed from the content server 20 and displays an image based on the received image content data. The communication line 22 is used to transmit data of image content that is streamed. As the communication line 22, various systems such as a network such as the Internet or an interface between devices such as IEEE1394 can be used.

In the multi-display system 41, the multi-display control unit 43 supplies image content data to the display units 45 to 48. The communication path 44 is a communication path for supplying image content data to the display units 45 to 48. The communication path 44 is configured by a network such as a LAN (Local Area Network), a WAN (Wide Area Network), or the Internet, for example. The display units 45 to 48 receive supply of image content data from the multi-display control unit 43. Each of the display units 45 to 48 displays a part of the image content based on the image content data belonging to its own display area.
Note that the multi-display control unit 43 and the display units 45 to 48 in the present embodiment have the same configuration as the multi-display control unit 23 and the display units 25 to 28 described in the first embodiment.

Subsequently, the time measurement unit of the multi-display control unit 43 according to the present embodiment obtains the communication time from the multi-display control unit 23 to each display unit 25 to 28 and the display processing time of each display unit 25 to 28. An example will be described. FIG. 12 is a diagram illustrating an example of a probe packet to which a time stamp is added.
The multi-display control unit 43 transmits the probe packet 90 to each of the display units 45 to 48, and returns the probe packet to which the time stamp is added as a response to the display unit 45 to 48, as shown in FIG. Receive from each.

  FIG. 12A shows a probe packet received from the display unit 45. The time stamp information 401 is a transmission time of the probe packet 90 in the multi display control unit 43. The time stamp information 402 is screen ID information indicating the display unit 45. The time stamp information 403 is reception time information of the probe packet 90 in the display unit 45. The time stamp information 404 is display processing completion time information in the display unit 45.

  FIG. 12B shows a probe packet received from the display unit 46. The time stamp information 405 is a transmission time of the probe packet 90 in the multi display control unit 43. The time stamp information 406 is screen ID information indicating the display unit 46. The time stamp information 407 is reception time information of the probe packet 90 in the display unit 46. The time stamp information 408 is display processing completion time information in the display unit 46.

  FIG. 12C shows a probe packet received from the display unit 47. The time stamp information 409 is a transmission time of the probe packet 90 in the multi display control unit 43. The time stamp information 410 is screen ID information indicating the display unit 47. The time stamp information 411 is reception time information of the probe packet 90 in the display unit 47. The time stamp information 412 is display processing completion time information in the display unit 47.

  FIG. 12D shows a probe packet received from the display unit 48. The time stamp information 413 is the transmission time of the probe packet 90 in the multi display control unit 43. The time stamp information 414 is screen ID information indicating the display unit 48. The time stamp information 415 is reception time information of the probe packet 90 in the display unit 48. The time stamp information 416 is display processing completion time information in the display unit 48.

  The time measurement unit includes reception time information 403, 407, 411, and 415 added after the screen ID information 402, 406, 410, and 414 indicating the display units 45 to 48, and display processing completion times 404, 408, and 411, 415 and the following calculation is performed.

First, the time measuring unit obtains the communication time to the display unit 45. In the example shown in FIG. 12, the communication time to the display unit 45 is 2 [ms] (= 2-0).
Further, the time measuring unit obtains the display processing time in the display unit 45. In the example shown in FIG. 12, the display processing time in the display unit 45 is 5 [ms] (= 7-2).

Secondly, the time measuring unit obtains the communication time to the display unit 46. In the example shown in FIG. 12, the communication time to the display unit 46 is 3 [ms] (= 5-2).
Further, the time measuring unit obtains the display processing time in the display unit 46. In the example shown in FIG. 12, the display processing time in the display unit 46 is 6 [ms] (= 11−5).

Thirdly, the time measuring unit obtains the communication time to the display unit 47. In the example shown in FIG. 12, the communication time to the display unit 47 is 2 [ms] (= 6-4).
Further, the time measuring unit obtains the display processing time in the display unit 47. In the example shown in FIG. 12, the display processing time in the display unit 47 is 4 [ms] (= 10−6).

Fourth, the time measurement unit obtains the communication time to the display unit 48. In the example shown in FIG. 12, the communication time to the display unit 48 is 3 [ms] (= 9-6).
Further, the time measuring unit obtains the display processing time in the display unit 48. In the example shown in FIG. 12, the display processing time in the display unit 48 is 5 [ms] (= 14-9).

Next, an example of a method for adjusting the transmission schedule of the image data packet 50 in the present embodiment will be described. FIG. 13 is a diagram illustrating an example of a transmission schedule of the image data packet 50.
In FIG. 13, time 501 is a communication time from the multi-display control device 43 to the display unit 45. Time 502 is a communication time from the multi-display control device 43 to the display unit 46. Time 503 is a communication time from the multi-display control device 43 to the display unit 47. Time 504 is a communication time from the multi-display control device 43 to the display unit 48.

  A time 505 is a display processing time in the display unit 45. Time 506 is a display processing time in the display unit 46. Time 507 is a display processing time in the display unit 47. Time 508 is a display processing time in the display unit 48.

First, the synchronization control unit in the multi-display control unit 43 performs the following processing based on the communication time and display processing time of each display unit 45-48. In other words, the synchronization control unit calculates the necessary time from when the multi-display control unit 43 transmits the image data packet 50 to when the display processing based on the image data packet 50 is completed in each display unit 45 to 48. . In the example shown in FIG. 13, it is calculated as follows.
The necessary time required for the display unit 45 to display the amount of image data is 7 [ms] (= 2 + 5).
The necessary time required for the display unit 46 to display the amount of image data is 9 [ms] (= 3 + 6).
The necessary time required for the display unit 47 to display the portion in charge of the image data is 6 [ms] (= 2 + 4).
The necessary time required for the display unit 48 to display the amount of image data is 8 [ms] (= 3 + 5).

  Then, the synchronization control unit determines the transmission order of the image data packet 50 as the display unit 46, the display unit 48, the display unit 45, and the display unit 47 from the magnitude of the necessary time calculated as described above. Further, the synchronization control unit transmits the image data packet 50 to each of the display units 45 to 48 at an optimum timing with respect to the scheduled display time 1/60 [sec] from the necessary time calculated as described above. Generate a packet transmission command.

  The data packet generator in the multi-display controller 43 adds information such as the transmission time to the image data packet 50 as a time stamp. Then, the data packet generation unit transmits the image data packet 50 to the display units 25 to 28 via the transmission / reception interface 60 in accordance with the packet transmission command generated by the synchronization control unit.

As described above, even if the multi-display control unit 43 and the display units 45 to 48 and the display units 45 to 48 are connected to each other, the image data packet 50 is the same as in the first embodiment. The transmission schedule can be determined.
Therefore, even if the communication path and communication time from the multi-display control unit to the display unit and the processing capability of the display units 25 to 28 are different, the display units synchronize with each other regardless of the connection form of the display units. Can be displayed. In addition, since the multi-display control unit that is the transmission source of the image data packet 50 adjusts the transmission schedule of the image data packet 50, the display units do not have a large memory and display images in synchronization between the display units. it can.

  Furthermore, in the present embodiment, time stamp information (reception time information, display processing completion time information, etc.) is added to the probe packet 90 for each display unit 45 to 48 and returned to the multi-display control unit 43. Therefore, the multi-display control unit 43 can obtain the communication time and the display processing time more efficiently.

(Other embodiments of the present invention)
In order to operate various devices to realize the functions of the above-described embodiments, program codes of software for realizing the functions of the above-described embodiments are provided to an apparatus or a computer in the system connected to the various devices. You may supply. What was implemented by operating said various devices according to the program stored in the computer (CPU or MPU) of the system or apparatus is also included in the category of the present invention.

  In this case, the program code of the software itself realizes the functions of the above-described embodiment. The program code itself and means for supplying the program code to a computer, for example, a recording medium storing the program code constitute the present invention. As a recording medium for storing the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  Further, the functions of the above-described embodiments are not only realized by executing the program code supplied by the computer. It goes without saying that the program code is also included in the embodiment of the present invention even when the function of the above-described embodiment is realized in cooperation with an operating system or other application software running on the computer. Yes.

Further, after the supplied program code is stored in the memory provided in the function expansion board of the computer, the CPU provided in the function expansion board performs part or all of the actual processing based on the instruction of the program code. Needless to say, the present invention includes the case where the functions of the above-described embodiments are realized by the processing.
Further, after the supplied program code is stored in the memory provided in the function expansion unit connected to the computer, the CPU or the like provided in the function expansion unit performs part or all of the actual processing based on the instruction of the program code. Do. Needless to say, the present invention includes the case where the functions of the above-described embodiments are realized by the processing.

  Note that each of the above-described embodiments is merely a specific example for carrying out the present invention, and the technical scope of the present invention should not be construed as being limited thereto. . That is, the present invention can be implemented in various forms without departing from the technical idea or the main features thereof.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the 1st Embodiment of this invention and shows an example of the schematic structure of the whole multi-display system. It is a figure which shows the 1st Embodiment of this invention and shows an example of a structure of the probe packet which makes a multi-display control part a transmission source. The time chart which shows the 1st Embodiment of this invention and demonstrates an example of operation | movement of the display units 25-28 at the time of adding a time stamp to a probe packet, and an example of the probe packet to which the time stamp was added are shown FIG. It is a figure which shows the 1st Embodiment of this invention and shows an example of a structure of an image data packet. It is a figure which shows the 1st Embodiment of this invention and shows an example of a structure of a multi-display control part. It is a figure which shows the 1st Embodiment of this invention and shows an example of a structure of a display unit. It is a flowchart which shows the 1st Embodiment of this invention and demonstrates an example of the process operation with respect to the probe packet in a multi-display control part. 6 is a flowchart illustrating an example of a processing operation for an image data packet in the multi-display control unit according to the first embodiment of this invention. It is a figure which shows the 1st Embodiment of this invention and shows an example of the transmission schedule of an image data packet. It is a flowchart which shows the 1st Embodiment of this invention and demonstrates an example of the process operation with respect to the packet in a display unit. It is a figure which shows the 2nd Embodiment of this invention and shows an example of the schematic structure of the whole multi-display system. It is a figure which shows the 2nd Embodiment of this invention and shows an example of the probe packet to which the time stamp was added. It is a figure which shows the 2nd Embodiment of this invention and shows an example of the transmission schedule of an image data packet.

Explanation of symbols

20 content server 21 multi display system 23 multi display control unit 25-28, 45-48 display unit 50 image data packet 90 probe packet 51, 91 header 52, 92 payload 53, 93 packet identification information unit 54, 94 transmission destination ID unit 55, 95 Attribute data portion 56 Scheduled display time portion 96 Transmission time portion 97 Screen ID portion 98 Arrival time portion 99 Processing completion time portion

Claims (11)

A display control device that performs control for displaying image content data on a plurality of display devices constituting one display screen,
Transmission data including reference image data corresponding to image content data to be displayed on the display device and information indicating a display device that is a display destination of an image based on the reference image data is transmitted to the display device. Provisional image data transmission means;
Receiving means for receiving, from the display device, reply data based on the transmission data transmitted by the temporary image data transmitting means;
A display comprising: time deriving means for obtaining a communication time to each of the plurality of display devices and a display processing time in the plurality of display devices based on the reply data received by the receiving means. Control device.   In the reply data, the display device that is the display destination of the image based on the reference image data receives reception time information related to the time when the transmission data including the reference image data is received, and the reference image included in the received transmission data The display control apparatus according to claim 1, further comprising display processing completion time information relating to a time at which the data display processing is completed.   The reply data is data in which information including the reception time information and the display processing completion time information is added as a time stamp to the transmission data transmitted by the transmission unit. The display control apparatus described. Adjusting means for adjusting a transmission schedule of the image content data based on the communication time and the display processing time obtained by the time deriving means;
A scheduled display time deriving unit for obtaining a scheduled display time of the image content data on the display device;
Based on the transmission schedule adjusted by the adjusting means, the display device includes display data including the image content data and information related to the scheduled display time in the display device that performs display processing based on the image content data. The display control apparatus according to claim 1, further comprising a main image data transmission unit that transmits the image data to the display. A display device constituting a part of one display screen,
Transmitting data including reference image data corresponding to image content data to be displayed and information indicating a display device serving as an image display destination based on the reference image data for displaying the image content data Receiving means for receiving from a display control device for controlling;
When information indicating that the display device that is the display destination of the image based on the reference image data is its own display device is included in the transmission data received by the receiving unit, the reference image data is displayed. Display processing means for performing processing;
Reply data including information relating to the time when the display processing of the reference image data is completed by the display processing means and reception time information relating to the time when the transmission data including the reference image data is received is returned to the display control device. And a reply means. A display system having a plurality of display devices that constitute one display screen and a display control device that performs control for displaying image content data on the one display screen,
The display control device includes transmission data including reference image data corresponding to image content data to be displayed on the display device, and information indicating a display device serving as an image display destination based on the reference image data. Provisional image data transmission means for transmitting to the display device;
Receiving means for receiving, from the display device, reply data to the transmission data transmitted by the temporary image data transmitting means;
Based on the reply data received by the receiving means, it has communication time to each of the plurality of display devices, and time derivation means for obtaining display processing time in the plurality of display devices,
The plurality of display devices include receiving means for receiving transmission data transmitted by the temporary image data transmitting means;
When information indicating that the display device that is the display destination of the image based on the reference image data is its own display device is included in the transmission data received by the receiving unit, the reference image data is displayed. Display processing means for performing processing;
The reply data including the information related to the time when the display processing of the reference image data is completed by the display processing means and the reception time information related to the time when the transmission data including the reference image data is received is returned to the display control device. And a reply means. Transmission data including reference image data corresponding to image content data to be displayed on a display screen constituted by a plurality of display devices, and information indicating a display device that is an image display destination based on the reference image data A provisional image data transmission step for transmitting to the display device;
A transmission data receiving step in which the display device receives the transmission data transmitted in the temporary image data transmission step;
When the transmission data received by the receiving step includes information indicating that the display device that is an image display destination based on the reference image data is its own display device, the reference image data is displayed. Display processing steps for processing,
A reply step of returning reply data including information related to the time when the display processing of the reference image data is completed by the display processing step and reception time information related to the time when the transmission data including the reference image data is received;
A reception step of receiving the reply data returned by the reply step from the display device;
A display comprising: a time deriving step for obtaining a communication time to each of the plurality of display devices and a display processing time in the plurality of display devices based on the reply data received in the receiving step. Control method.   The reply data is data in which information including the reception time information and the display processing completion time information is added as a time stamp to the transmission data transmitted in the transmission step. The display control method described. An adjustment step of adjusting a transmission schedule of the data of the image content based on the communication time and the display processing time obtained by the time derivation step;
A scheduled display time derivation step for obtaining a scheduled display time of the image content data on the display device;
Based on the transmission schedule adjusted by the adjustment step, the display device includes display data including the image content data and information related to the scheduled display time in the display device that performs display processing based on the image content data. The display control method according to claim 7, further comprising: a main image data transmission step of transmitting to the image data. A computer program for causing a computer to perform control for displaying image content data on a plurality of display devices constituting one display screen,
Transmission data including reference image data corresponding to image content data to be displayed on the display screen and information indicating a display device that is an image display destination based on the reference image data is transmitted to the display device. Temporary image data transmission step to perform,
A reception step of receiving, from the display device, reply data based on the transmission data transmitted by the provisional image data transmission step;
The computer is caused to execute a time derivation step for obtaining a communication time to each of the plurality of display devices and a display processing time in the plurality of display devices based on the reply data received in the reception step. Computer program. A computer program for causing a computer to display an image on a display device constituting a part of one display screen,
Receiving transmission data including reference image data corresponding to data of image content to be displayed and information indicating a display device that is a display destination of an image based on the reference image data; and
When the transmission data received by the receiving step includes information indicating that the display device that is an image display destination based on the reference image data is its own display device, the reference image data is displayed. Display processing steps for processing,
A reply step of returning reply data including information relating to the time when the display processing of the reference image data is completed by the display processing step and reception time information relating to the time when the transmission data including the reference image data is received; A computer program that is executed by a computer.

Images