Multi-display system, leading electronic apparatus, following electronic apparatus, and display method

Abstract

Upon receiving an identification result from a first electronic apparatus, following electronic apparatuses (111, 112, 113) each, without performing identification processing for identifying a video signal inputted thereto, perform, with respect to each device related to display processing of a video based on the video signal therein, setting corresponding to the type of the video signal in accordance with the identification result. A leading electronic apparatus (110), which is the first electronic apparatus, determines whether or not there has been a change in a video signal inputted thereto prior to the following electronic apparatuses, without determining whether or not a mute notification has been received from any of the electronic apparatuses other than the leading electronic apparatus, identifies the video signal inputted thereto, notifies each of the electronic apparatuses other than the leading electronic apparatus of an identification result and a mute instruction, and performs setting corresponding to the type of the video signal in accordance with the identification result. When the setting of the device has been completed, each electronic apparatus unmutes the video and displays the video.

Description

Multi-display system, leading electronic device, following electronic device, display method

[0001] The present invention relates to a multi-display system, a leading electronic device, a following electronic device, and a display method.

[0002] In a multi-display system, multiple display areas are arranged adjacent to each other vertically and horizontally, and multiple electronic devices (e.g., projectors) each project an image based on a video signal onto the target display area. This allows a single display screen to be displayed by projecting an image onto each display area (see, for example, Patent Document 1). In such a multi-display system, the timing at which the video signals are input to each projector does not necessarily coincide. Therefore, when each projector projects an image based on its respective video signal, the image starts to be displayed at different times in each display area. As a result, the images start to be displayed separately in each display area, preventing the images from being displayed simultaneously, creating a sense of discomfort for users viewing the display screen.

[0003] In such a multi-display system, when a video signal is input to multiple projectors, each projector mutes the display of the video based on the video signal, performs a setting process for displaying the video signal, and then unmutes the video display. This allows the display timing of the images projected by each of the multiple projectors to be synchronized.

[0004] Japanese Patent Application Laid-Open No. 2005-274937

[0005] However, there is a problem in that it takes a long time from when the video signal is supplied to each electronic device until the video is displayed on the display screen.

[0006] One aspect of the present invention is a multi-display system including a plurality of electronic devices that display video based on a video signal, the plurality of electronic devices being numbered first to N (N being a natural number of 2 or greater), each of which is supplied with a video signal. Each of the follow-up electronic devices other than the first electronic device includes: a mute notification determination unit that determines whether a mute notification for muting the display of video based on the video signal has been received from any of the electronic devices other than the first electronic device; a mute processing unit that performs video mute processing in response to receiving a mute notification from any of the electronic devices other than the first electronic device; a determination result determination unit that determines whether a determination result for determining the video signal has been received from any of the electronic devices other than the first electronic device; a second device setting unit that, upon receiving the determination result from the first electronic device among the electronic devices other than the first electronic device, sets each device related to the display processing of video based on the video signal in the first electronic device according to the type of the video signal without performing a determination process for determining the video signal input to the first electronic device; a second mute canceling unit that receives the notification indicating the completion of the setting from each electronic device and, when the device setting of all of the plurality of electronic devices including the main electronic device is completed, cancels the video mute of the main electronic device and causes the video based on the video signal to be displayed on a display unit, wherein the main electronic device has: a signal change determining unit that determines whether or not there has been a change in the video signal input to the main electronic device without determining whether or not a mute notification to mute the display of the video based on the video signal has been received from any of the electronic devices other than the main electronic device; a determining unit that determines whether or not there has been a change in the video signal input to the main electronic device based on the determination result of the signal change determining unit; and a notifying unit that, when the video signal is determined by the determining unit, notifies each of the electronic devices other than the main electronic device of the determination result and a mute instruction to mute the display of the video based on the video signal; and, in response to the determination of the video signal by the determining unit,A multi-display system comprising: a first mute unit that mutes the display of video based on a video signal of the main electronic device; a first device setting unit that, when a determination result is obtained by the determination unit, sets each device related to the display processing of video based on the video signal in the main electronic device according to the type of the video signal based on the determination result; a first setting completion notifying unit that, when the setting processing of the device is completed, sends a notification indicating that the setting is complete to each electronic device other than the main electronic device; and a first mute release unit that receives the notification indicating that the setting is complete from each electronic device, and, when device setting is complete for all of the plurality of electronic devices including the main electronic device, releases the video mute of the main electronic device and causes the video based on the video signal to be displayed on a display unit.

[0007] Furthermore, one aspect of the present invention is a multi-display system including a plurality of electronic devices that display video based on a video signal, the plurality of electronic devices being first to Nth electronic devices (N is a natural number of 2 or more), each of which is supplied with a video signal, and each of the follow-up electronic devices other than the first electronic device includes a mute notification determination unit that determines whether a mute notification for muting the display of video based on the video signal has been received from any of the electronic devices other than the first electronic device, a mute processing unit that performs video muting processing in response to receiving a mute notification from any of the electronic devices other than the first electronic device, a determination result determination unit that determines whether a determination result of the video signal has been received from any of the electronic devices other than the first electronic device, and The tracking electronic device has: a second device setting unit that, by receiving a discrimination result from a first electronic device, sets each device related to the display processing of video based on a video signal in the tracking electronic device according to the type of the video signal in accordance with the discrimination result received from the first electronic device, without performing a discrimination process to discriminate the video signal input to the tracking electronic device; a second setting completion notification unit that, when the setting process of the device is completed, sends a notification indicating that the setting is complete to each electronic device other than the tracking electronic device; and a second mute release unit that receives the notification indicating that the setting is complete from each electronic device, and, when device setting is complete for all of the plurality of electronic devices including the tracking electronic device, releases the video mute of the tracking electronic device and displays the video based on the video signal on a display unit.

[0008] Another aspect of the present invention is a multi-display system including a plurality of electronic devices that display video based on a video signal, the plurality of electronic devices being first to Nth electronic devices (N is a natural number of 2 or more), each of which is supplied with a video signal, the first electronic device being a leading electronic device, comprising: a signal change determination unit that determines whether or not there has been a change in the video signal input to the leading electronic device, without determining whether or not a mute notification for muting the display of video based on the video signal has been received from any electronic device other than the leading electronic device; a determination unit that determines whether or not there has been a change in the video signal input to the leading electronic device based on the determination result of the signal change determination unit; and when the determination unit determines that the video signal has changed, transmits the determination result and a mute instruction for muting the display of video based on the video signal to each of the electronic devices other than the leading electronic device. a first muting unit that mutes the display of video based on the video signal of the self-led electronic device in response to the discrimination of the video signal by the discrimination unit; a first device setting unit that, when a discrimination result is obtained by the discrimination unit, performs settings according to the type of the video signal for each device related to the display processing of video based on the video signal in the self-led electronic device based on the discrimination result; a first setting completion notifying unit that, when the setting processing of the device is completed, sends a notification indicating that the setting is complete to each electronic device other than the self-led electronic device; and a first mute release unit that receives the notification indicating that the setting is complete from each electronic device, and, when device setting is completed for all of the plurality of electronic devices including the self-led electronic device, releases the video mute of the self-led electronic device and causes the video based on the video signal to be displayed on a display unit.

[0009] Furthermore, one aspect of the present invention is a display method in a multi-display system including a plurality of electronic devices that display video based on a video signal, the plurality of electronic devices being first to Nth electronic devices (N is a natural number of 2 or more), a video signal being supplied to each electronic device, a mute notification determination unit in a follow-up electronic device other than the first electronic device determining whether or not a mute notification for muting a display of video based on the video signal has been received from any electronic device other than the first electronic device, a mute processing unit performing video mute processing in response to receiving the mute notification from any electronic device other than the first electronic device, a discrimination result determination unit determining whether or not a discrimination result for discriminating the video signal has been received from any electronic device other than the first electronic device, and a second device setting unit receiving the discrimination result from the first electronic device among the electronic devices other than the first electronic device, thereby performing setting according to the type of the video signal for each device related to the display processing of video based on the video signal in the first electronic device without performing discrimination processing for discriminating the video signal input to the first electronic device. a second setting completion notifying unit, when setting processing of the device is completed, transmitting a notification indicating that setting has been completed to each of the electronic devices other than the main electronic device; a second mute canceling unit, receiving a notification indicating that setting has been completed from each of the electronic devices, and when device setting has been completed for all of the plurality of electronic devices including the main electronic device, canceling video mute of the main electronic device and displaying video based on the video signal on a display unit; the master electronic device, which is the first electronic device, determines whether there has been a change in the video signal input to the main electronic device before the follow-up electronic device, without determining whether the signal change determining unit has received a mute notification to mute the display of video based on the video signal from any of the electronic devices other than the main electronic device; a determining unit, after determining that there has been a change in the video signal based on the determination result of the signal change determining unit, determines the video signal input to the main electronic device; and when the determining unit has determined that the video signal has changed, a notifying unit, notifying each of the electronic devices other than the main electronic device of the determination result and a mute instruction to mute the display of video based on the video signal; and a first mute unit,In response to the discrimination of the video signal by the discrimination unit, the display of video based on the video signal of the main electronic device is muted; when the discrimination unit obtains a discrimination result, a first device setting unit performs settings according to the type of the video signal for each device related to the display processing of video based on the video signal in the main electronic device based on the discrimination result; when the setting processing of the device is completed, a first setting completion notifying unit sends a notification indicating that the setting is complete to each electronic device other than the main electronic device; a first mute canceling unit receives the notification indicating that the setting is complete from each electronic device; and when device setting is completed for all of the plurality of electronic devices including the main electronic device, the video muting of the main electronic device is canceled and video based on the video signal is displayed on a display unit.

[0010] Furthermore, one aspect of the present invention is a multi-display system including a plurality of electronic devices that display video based on a video signal, the plurality of electronic devices include first to Nth electronic devices (N is a natural number of 2 or more), and a video signal is supplied to each of the electronic devices. In each of the following electronic devices other than the first electronic device, a mute notification determination unit determines whether a mute notification for muting the display of video based on the video signal has been received from any of the electronic devices other than the first electronic device, a mute processing unit performs video muting processing in response to receiving the mute notification from any of the electronic devices other than the first electronic device, a discrimination result determination unit determines whether a discrimination result of discriminating the video signal has been received from any of the electronic devices other than the first electronic device, and a second device setting unit determines whether a discrimination result of discriminating the video signal has been received from any of the electronic devices other than the first electronic device. a second setting completion notification unit that, when the setting process for the device is completed, sends a notification indicating that the setting has been completed to each electronic device other than the first electronic device; a second mute release unit that receives a notification indicating that the setting has been completed from each electronic device; and, when the device setting has been completed for all of the plurality of electronic devices, including the first electronic device, releases the video mute of the first electronic device and displays the video based on the video signal on a display unit.

[0011] Furthermore, one aspect of the present invention is a multi-display system including a plurality of electronic devices that display video based on a video signal, the plurality of electronic devices include first to Nth electronic devices (N is a natural number of 2 or more), and a video signal is supplied to each of the electronic devices. In the first electronic device, a signal change determination unit determines whether or not there has been a change in the video signal input to the first electronic device before the electronic devices other than the first electronic device have received a mute notification to mute the display of the video based on the video signal, without determining whether or not a mute notification to mute the display of the video based on the video signal has been received from any electronic device other than the first electronic device. After determining that there has been a change in the video signal based on the determination result of the signal change determination unit, a determination unit determines the video signal input to the first electronic device, and when the video signal is determined by the determination unit, a notification unit determines the result of the determination and a mute instruction to mute the display of the video based on the video signal. a first muting unit mutes the display of the video based on the video signal of the self-led electronic device in response to the discrimination of the video signal by the discrimination unit; a first device setting unit, when the discrimination unit obtains a discrimination result, sets each device related to the display processing of the video based on the video signal in the self-led electronic device according to the discrimination result, based on the discrimination result; a first setting completion notifying unit, when the setting processing of the device is completed, sends a notification indicating that the setting is complete to each electronic device other than the self-led electronic device; a first mute canceling unit receives the notification indicating that the setting is complete from each electronic device; and when device setting is completed for all of the plurality of electronic devices including the self-led electronic device, cancels the video mute of the self-led electronic device and causes the video based on the video signal to be displayed on a display unit.

[0012] According to the present invention, it is possible to reduce the length of time it takes from when a video signal is supplied to each electronic device until the video is displayed on the display screen.

[0013] FIG. 1 is a schematic diagram showing the configuration of a multi-display system S according to a first embodiment. FIG. 2 is a schematic functional block diagram explaining the function of a projector 110. FIG. 3 is a diagram showing an example of a signal table. FIG. 4 is a flowchart explaining the operation of a projector 110. FIG. 5 is a diagram showing the states of the mute flags of projectors 110 to 113. FIG. 6 is a schematic diagram showing the configuration of a multi-display system Sa according to a second embodiment. FIG. 7 is a schematic diagram showing the configuration of a multi-display system Sb according to a third embodiment.

[0014] A multi-display system according to an embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of a multi-display system S according to a first embodiment. The multi-display system S includes a plurality of electronic devices that display images based on video signals. The electronic devices are, for example, projectors. A display device 101 is connected to a video signal supply device 102 via a communication cable. The display device 101 is used as a monitor for the video signal supply device 102.

[0015] The video signal supply device 102 is connected to the display device 101 via a communication cable, and is also connected to the distributor 103 via a communication cable. The video signal supply device 102 outputs a video signal corresponding to the content to the distributor 103 via the communication cable. This communication cable may be, for example, an HDMI (registered trademark) (High Definition Multimedia Interface) cable. The video signal supply device 102 also outputs a video signal and various information to the display device 101. The video signal supply device 102 is, for example, a computer.

[0016] The distributor 103 is connected to the video signal supply device 102 via a communication cable. The distributor 103 is also connected to the projectors 110, 111, 112, and 113 via different communication cables. The communication cables used to connect the distributor 103 to each projector may be, for example, an HDMI (registered trademark) cable. The distributor 103 has a first terminal 103a, a second terminal 103b, a third terminal 103c, and a fourth terminal 103d. The first terminal 103a is connected to the input terminal 114 of the projector 110 via a communication cable. The second terminal 103b is connected to the input terminal 117 of the projector 111 via a communication cable. The third terminal 103c is connected to the input terminal 120 of the projector 112 via a communication cable. The fourth terminal 103d is connected to the input terminal 123 of the projector 113 via a communication cable.

[0017] Distributor 103 supplies the video signal output from video signal supply device 102 to projector 110, projector 111, projector 112, and projector 113. That is, distributor 103 distributes the video signal output from video signal supply device 102 to each of the four projectors.

[0018] The remote control 104 wirelessly transmits a control signal and a switching signal to each of the projectors (projector 110, projector 111, projector 112, and projector 113). The control signal is a signal that turns the power on or off. The switching signal is a signal that switches which device receives the video signal.

[0019] The screen 105 displays images by projecting images from each projector (projector 110, projector 111, projector 112, projector 113). The screen 105 is divided into a plurality of display areas (image display areas). Here, the screen 105 is divided into two sections each in the vertical and horizontal directions, resulting in a total of four display areas: display area 106, display area 107, display area 108, and display area 109. These display areas 106, 107, 108, and 109 are installed adjacent to each other. The display area 106 is assigned as the area onto which an image is projected by the projector 110. The display area 107 is assigned as the area onto which an image is projected by the projector 112. The display area 108 is assigned as the area onto which an image is projected by the projector 111. The display area 109 is allocated as an area onto which an image is projected by a projector 113 .

[0020] The projector 110 receives a video signal supplied from the video signal supply device 10 via the distributor 103 and projects an image based on the input video signal onto the display area 106. The projector 110 has an input terminal 114, an input terminal 115, and an output terminal 116. The input terminal 114 is connected to the first terminal 103a of the distributor 103 via a communication cable (HDMI (registered trademark) cable) and inputs a video signal. The input terminal 115 is an input terminal capable of inputting a signal based on the HDBaseT communication standard. The input terminal 115 is not connected to other electronic devices (projectors 111, 12, and 112). The output terminal 116 is an output terminal capable of outputting a signal based on the HDBaseT standard. The projector 110 enlarges the image based on the video signal input from the input terminal 114, dividing the image into two vertically and two horizontally, and projects the image corresponding to the upper left area onto the display area 106 of the screen 105. In this case, the projector 110 discards the upper right, lower left, and lower right areas of the divided areas and does not project.

[0021] The projector 111 receives the video signal supplied from the video signal supply device 10 via the distributor 103 and projects an image based on the input video signal onto the display area 108. The projector 111 has an input terminal 117, an input terminal 118, and an output terminal 119. The input terminal 117 is connected to the second terminal 103b of the distributor 103 via a communication cable (HDMI (registered trademark) cable) and inputs the video signal. The input terminal 118 is an input terminal that can input a signal based on the HDBaseT communication standard. The input terminal 118 is connected to the output terminal 116 of the projector 110 via a communication cable (e.g., a LAN (Local Area Network) cable) that can communicate a signal based on HDBaseT. The output terminal 119 is an output terminal that can output a signal based on HDBaseT. Projector 111 divides an image based on a video signal input from input terminal 117 into two vertical and two horizontal regions, and enlarges the image corresponding to the upper right region of the divided region, and projects it onto display region 108 of screen 105. In this case, projector 111 discards the upper left, lower left, and lower right regions of the divided region and does not project them.

[0022] The projector 112 receives the video signal supplied from the video signal supply device 10 via the distributor 103 and projects an image based on the input video signal onto the display area 107. The projector 112 has an input terminal 120, an input terminal 121, and an output terminal 122. The input terminal 120 is connected to the third terminal 103c of the distributor 103 via a communication cable (HDMI (registered trademark) cable) and inputs the video signal. The input terminal 121 is an input terminal that can input a signal based on the HDBaseT communication standard. The input terminal 121 is connected to the output terminal 119 of the projector 111 via a communication cable (e.g., a LAN cable) that can communicate a signal based on HDBaseT. The output terminal 122 is an output terminal that can output a signal based on HDBaseT. Projector 112 divides an image based on a video signal input from input terminal 120 into two vertical and two horizontal regions, and enlarges the image corresponding to the lower left region of the divided region, and projects it onto display region 107 of screen 105. In this case, projector 112 discards the upper left, upper right, and lower right regions of the divided region and does not project them.

[0023] The projector 113 receives a video signal supplied from the video signal supply device 10 via the distributor 103 and projects an image based on the input video signal onto the display area 109. The projector 113 has an input terminal 123, an input terminal 124, and an output terminal 125. The input terminal 123 is connected to the fourth terminal 103d of the distributor 103 via a communication cable (HDMI (registered trademark) cable) and inputs a video signal. The input terminal 124 is an input terminal capable of inputting a signal based on the HDBaseT communication standard. The input terminal 124 is connected to the output terminal 122 of the projector 112 via a communication cable (e.g., a LAN cable) capable of communicating a signal based on the HDBaseT. The output terminal 125 is an output terminal capable of outputting a signal based on the HDBaseT. In this embodiment, since the number of projectors connected to the distributor 103 is four, no other projectors are connected downstream of the output terminal 125. When multi-display system S is configured to include five or more projectors, output terminal 125 is connected to an input terminal of a subsequent projector that can receive an HDBaseT-based signal. Projector 113 divides an image based on a video signal input from input terminal 123 into two vertical and two horizontal regions, and enlarges the image corresponding to the lower right region of the divided region, and projects it onto display region 109 of screen 105. In this case, projector 112 discards the upper left, upper right, and lower left regions of the divided region and does not project them.

[0024] With this configuration, the multi-display system S can project an image based on the video signal supplied from the video signal supply device 102 onto the screen 105 .

[0025] If an image is projected using only one projector to fit the size of screen 105, the brightness of the projected image may fall short of the target brightness. The above-described multi-display system S projects images onto screen 105 using four projectors. This makes it possible to project images to fit the size of screen 105 while ensuring the target brightness.

[0026] Here, distributor 103 acquires EDID information of projector 110 from projector 110 through the communication cable connected to first terminal 103a, and outputs a video signal corresponding to the optimum resolution of projector 110 to projector 110. Similarly, distributor 103 acquires EDID information of projector 111 from projector 111 through second terminal 103b, and outputs a video signal corresponding to the optimum resolution of projector 111 to projector 111. Similarly, distributor 103 acquires EDID information of projector 112 from projector 112 through third terminal 103c, and outputs a video signal corresponding to the optimum resolution of projector 112 to projector 112. Similarly, distributor 103 acquires EDID information of projector 112 from projector 112 via fourth terminal 103d, and outputs a video signal corresponding to the optimum resolution of projector 112 to projector 112. This acquisition of EDID information is performed in the order of projector 110, projector 111, projector 112, and projector 113. Therefore, the video signals output from first terminal 103a, second terminal 103b, third terminal 103c, and fourth terminal 103d of distributor 103 are not output simultaneously, but rather start output in the order of first terminal 103a, second terminal 103b, third terminal 103c, and fourth terminal 103d.

[0027] Furthermore, in the above-described multi-display system S, the projectors are connected by a communication cable (e.g., a LAN cable) compatible with HDBaseT. In this case, for example, each projector can receive a video signal transmitted via an HDMI (registered trademark) cable and exchange commands between the devices via the LAN cable. In this embodiment, when communicating via the LAN cable, the projectors only transmit commands based on the HDBaseT standard, and do not transmit video signals between the projectors. For example, when sending and receiving commands between the projectors, such as sending a command from projector 110 to projector 113 or from projector 112 to projector 110, communication can be performed via the LAN cable. In this case, the projectors can send and receive commands to and from each other as if they were connected to each other via a router.

[0028] Furthermore, whether or not a projector is the first projector (first electronic device) among the multiple projectors (110, 111, 112, 113) is set in advance. The first projector may be, for example, a projector among the multiple projectors (110, 111, 112, 113) to which a video signal is input before at least one other projector. Furthermore, it is preferable that the first projector be the projector to which a video signal is input first, in that this prevents a long time from when a video signal is supplied until an image is displayed on a display screen.

[0029] In the multi-display system S, numbers are assigned in advance to the first terminal 103a, second terminal 103b, third terminal 103c, and fourth terminal 103d, which are the output terminals of the distributor 103. Each projector (110, 111, 112, 113) recognizes to which of the first terminal 103a, second terminal 103b, third terminal 103c, and fourth terminal 103d of the distributor 103 it is connected, thereby identifying whether it is the first projector (first electronic device) or a second or subsequent projector (second electronic device, third electronic device, fourth electronic device). For example, the number 1 is assigned to the first terminal 103a, and the numbers 2, 3, and 4 are assigned to the second terminal 103b, third terminal 103c, and fourth terminal 103d. Each projector (110, 111, 112, 113) can identify whether it is the first projector by specifying the assigned number, and can determine whether the display area to be projected is display area 106, display area 107, display area 108, or display area 109. In this embodiment, projector 110 is connected to first terminal 103a and functions as the first projector (hereinafter also referred to as the lead projector). Projector 111 is connected to second terminal 103b, projector 112 is connected to third terminal 103c, and projector 113 is connected to fourth terminal 103d and 3a, and functions as a projector other than the first projector (hereinafter also referred to as a follower projector).

[0030] Fig. 2 is a schematic functional block diagram illustrating the functions of the projector 110. Although Fig. 2 illustrates the functions of the projector 110, the projectors 111, 112, and 113 have the same functions as those illustrated in Fig. 2.

[0031] In this figure, a projector 110 has a communication unit 1100 , a control unit 1101 , a first function unit 110 A, a second function unit 110 B, and a storage unit 1110 .

[0032] The communication unit 1100 communicates with an external device (e.g., the video signal supply device 102) via an HDMI (registered trademark) cable. The communication unit 1100 also communicates with an external device (e.g., a projector) via a LAN cable. The control unit 1101 controls each unit within the projector. For example, the control unit 1101 determines whether the projector itself is the first projector, and based on the determination result, causes either the first function unit 110A or the second function unit 110B to execute processing. If the projector itself is the first projector, the control unit 1101 causes the first function unit 110A to execute processing, and if the projector itself is not the first projector, causes the second function unit 110B to execute processing.

[0033] The first function unit 110A has a function for operating as the first projector when it is determined that the own projector is the first projector. The second function unit 110B has a function for operating as a projector other than the first projector when it is determined that the own projector is a projector other than the first projector.

[0034] The first functional unit 110A has a signal change determination unit 1102, a match determination unit 1103, a discrimination unit 1104, a notification unit 1105, a first mute unit 1106, a first device setting unit 1107, a first setting completion notification unit 1108, and a first mute cancellation unit 1109.

[0035] The signal change determination unit 1102 determines whether a change has occurred in the video signal input to the main electronic device (e.g., step S405, described later) without determining whether a mute notification for muting the display of a video based on a video signal has been received from any electronic device other than the main electronic device (e.g., step S402, described later). The signal change determination unit 1102 can determine whether a change has occurred in the video signal input to the main electronic device before the tracking projector. Here, the signal change determination unit 1102 analyzes the video signal and obtains signal information, which is information about the video signal, based on the analysis results. The signal information includes, for example, at least one of the following: presence or absence of a video signal, horizontal frequency, vertical frequency, horizontal signal polarity, vertical signal polarity, horizontal resolution, vertical resolution, total horizontal dot count, vertical line count, InfoFrame information, etc.

[0036] The signal change determination unit 1102 determines whether a change has occurred in the video signal based on whether a change has occurred in the signal information. For example, the signal change determination unit 1102 determines that a change has occurred in the video signal when a change has occurred in the signal information obtained by analyzing the video signal. The signal change determination unit 1102 determines that there has been no change in the video signal when there has been no change in the signal information. For example, the signal change determination unit 1102 determines whether the signal information obtained by the previous analysis matches the signal information obtained by the current analysis, and determines that there has been no change in the video signal when the previous and current signal information match, and determines that there has been a change in the video signal when the previous and current signal information do not match. Examples of cases in which it is determined that there has been a change in the video signal include when the value of any item included in the signal information changes, or when the video signal state indicated by any item is different, such as when a state in which there is no video signal changes to a state in which there is a video signal, when there is a change in the horizontal frequency, or when there is a change in the vertical signal polarity.

[0037] Based on the determination result of the signal change determination unit 1102, the match determination unit 1103 determines whether the signal information matches multiple times after it is determined that a change has occurred in the video signal. For example, the match determination unit 1103 may determine that the horizontal frequency obtained as the analysis result at a first timing does not match the horizontal frequency obtained as the analysis result at a subsequent second timing, but that the horizontal frequency obtained as the analysis result at a subsequent third timing matches the horizontal frequency obtained as the analysis result at the second timing and the subsequent timing. Furthermore, if the horizontal frequencies obtained at several timings after the third timing each match the horizontal frequency obtained at the second timing, the match determination unit 1103 determines that the value of the item in which the signal information has changed matches multiple times. The number of times defined as multiple matches may be determined arbitrarily. Furthermore, if the value of the item in which the change has occurred matches multiple times, the match determination unit 1103 determines that the video signal has no change.

[0038] When the determination unit 1104 determines that a video signal has changed based on the determination result of the signal change determination unit 1102, and then determines that the video signal no longer changes, it determines the video signal input to the electronic device (for example, step S407 described below). Furthermore, when the match determination unit 1103 determines that a match has occurred multiple times and then determines that the video signal no longer changes, the determination unit 1104 determines the video signal input to the electronic device. Furthermore, the determination unit 1104 identifies identification information according to the signal information of the video signal and outputs the identified identification information as the determination result. Here, different identification information (hereinafter also referred to as signal numbers) is pre-assigned according to the combination of various information included in the signal information. Here, the signal information can also be said to represent signal specifications. The signal number is uniquely determined according to the signal specifications. Therefore, it is possible to identify the signal information from the signal number.

[0039] When the discrimination unit 1104 discriminates the video signal, the notification unit 1105 notifies each electronic device other than the main electronic device of the discrimination result and a mute instruction to mute the display of the video based on the video signal by transmitting the discrimination result and the mute instruction to each electronic device other than the main electronic device via a communication cable (for example, step S408 described later). The first mute unit 1106 mutes the display of the video based on the video signal in the main electronic device in response to the discrimination unit 1104 discriminating the video signal (for example, step S408 described later). The mute status is indicated by a mute flag. A mute flag of "1" indicates that mute is off (not muted), and a mute flag of "0" indicates that mute is on (muted).

[0040] When the determination unit 1104 obtains a determination result, the first device setting unit 1107 performs settings for each device related to the display processing of video based on the video signal in the main electronic device according to the determination result, in accordance with the type of video signal (e.g., step S410 described later). When the device setting processing is completed, the setting completion notifying unit 1108 sends a notification indicating that the setting is complete to each electronic device other than the main electronic device (e.g., step S412 described later). The first mute canceling unit 1109 receives the notification indicating that the setting is complete from each electronic device, and when the device setting of all of the multiple electronic devices, including the main electronic device, is completed (e.g., step S413—YES described later), the first mute canceling unit 1109 cancels the video mute of the main electronic device (e.g., step S414 described later) and displays the video based on the video signal on the display unit.

[0041] Next, the second functional unit 110B has a mute notification determination unit 1113 , a mute processing unit 1114 , a discrimination result determination unit 1115 , a second device setting unit 1116 , a second setting completion notification unit 1117 , and a second mute cancellation unit 1118 .

[0042] The mute notification determination unit 1113 determines whether a mute notification to mute the display of video based on the video signal has been received from any electronic device other than the electronic device itself (for example, step S402 described below). Muting the video display is a state in which video based on the video signal is not displayed. For example, even if a state in which playback of video based on the video signal can be started is reached, playback is stopped without starting. Furthermore, when the video display is muted, no video may be projected from the projector, or the entire screen may be projected with a single color (for example, black).

[0043] The mute processing unit 1114 performs a video mute process to mute the video display in response to receiving a mute notification from any electronic device other than the subject electronic device (for example, step S403 described later). The discrimination result determination unit 1115 determines whether the discrimination result of the video signal has been received from any electronic device other than the subject electronic device (for example, step S404 described later).

[0044] The second device setting unit 1116 receives the determination result from the leading electronic device among the electronic devices other than the main electronic device, and without performing a determination process (e.g., step S407 described later) to determine the video signal input to the main electronic device, sets each device related to the video display process based on the video signal within the main electronic device according to the type of video signal in accordance with the determination result received from the leading electronic device (e.g., step S410 described later).

[0045] When the device setting process is completed, the second setting completion notifying unit 1117 transmits a notification indicating that the setting is complete to each of the electronic devices other than the main electronic device (for example, step S412 described later). The second mute canceling unit 1118 receives a notification indicating that the setting is complete from each of the electronic devices, and when the device setting is complete for all of the multiple electronic devices including the main electronic device (for example, step S413-YES described later), the second mute canceling unit 1118 cancels the video mute of the main electronic device (for example, step S414 described later) and displays the video based on the video signal on the display unit.

[0046] The storage unit 1110 stores various types of information. The storage unit 1110 stores, for example, a signal table. FIG. 3 is a diagram showing an example of the signal table. The signal table is data in which signal numbers are associated with signal information. For example, signal number "0001" is associated with signal information such as a horizontal frequency of "f11" and a vertical frequency of "f21."

[0047] Next, the operation of the projector when the output of a video signal from the video signal supply device 102 to the distributor 103 is started will be described. When a playback instruction is input to the video signal supply device 102 from an external device, the video signal supply device 102 starts outputting a video signal to the distributor 103. When the output of the video signal starts, the distributor 103 detects that the input of the video signal has started via the HDMI (registered trademark) cable. Next, the distributor 103 acquires an optimal resolution signal included in the EDID information of the projector 110, converts the video signal input to the distributor 103 to a resolution corresponding to the EDID information, and outputs the converted video signal to the projector 110. Next, the distributor 103 acquires an optimal resolution signal included in the EDID information of the projector 111, converts the video signal input to the distributor 103 to a resolution corresponding to the EDID information, and outputs the converted video signal to the projector 111. Furthermore, distributor 103 acquires an optimal resolution signal included in the EDID information of projector 112, then converts the video signal input to distributor 103 to a resolution corresponding to the EDID information, and outputs the converted video signal to projector 112. Furthermore, distributor 103 acquires an optimal resolution signal included in the EDID information of projector 113, then converts the video signal input to distributor 103 to a resolution corresponding to the EDID information, and outputs the converted video signal to projector 113. In other words, distributor 103 starts outputting video signals in the order of projector 110, projector 111, projector 112, and projector 113. Next, projector 110, projector 111, projector 112, and projector 113 each perform various processes based on the video signal, thereby projecting an image based on the video signal input from distributor 103 onto the display areas (106, 107, 108, and 109) of the screen.

[0048] 4 is a flowchart illustrating the operation of the projector 110. Here, a case where various processes are performed based on the video signal of the projector 110 will be described, but the other projectors (111, 112, 113) also perform processes in the same manner as in FIG.

[0049] In the initial state, the mute flags of the projectors 110, 111, 112, and 113 are all set to "1," and the mute of the video display is off. Therefore, the video signal input from the video signal supply device 102 is projected onto the respective display areas from each projector.

[0050] The control unit 1101 of the projector 110 references the number assigned to the terminal of the distributor 103 to which the projector 110 is connected and determines whether the projector 110 is the first projector (step S401). In this case, the control unit 1101 of the projector 110 determines that the projector 110 is the first projector because the projector 110 is connected to the first terminal 103a of the distributor 103 and has been preset as the first projector (step S401-YES). The control unit 1101 then skips steps S402 and S403 and moves the process to step S404. The discrimination result determination unit 1115 of the projector 110 determines whether the discrimination result of the video signal has been received from another electronic device (one of the projectors (111, 112, 113)) (step S404). At this point, a video signal is input to projector 110, but no video signal is input to the other projectors (111, 112, 113), or even if a video signal is input, the other projectors (111, 112, 113) have not yet executed a discrimination process on the video signal. Therefore, no discrimination results have been received from the other projectors. Therefore, discrimination result determination unit 1115 of projector 110 determines that no discrimination results have been received from the other projectors (111, 112, 113) (step S404-NO), and the process proceeds to step S405.

[0051] Here, the determination process for obtaining the determination result of the video signal is performed by the determination unit 1104 of the first electronic device (here, for example, the projector 110) in step S407, which will be described later.

[0052] Next, the signal change determination unit 1102 of the projector 110 determines whether there has been a change in the video signal input from the distributor 103 to the main electronic device (step S405). Here, the signal change determination unit 1102 skips the determination of whether a mute notification for muting the video display based on the video signal has been received from any electronic device other than the main electronic device (step S402) and the video mute process based on the determination result (step S403), thereby determining whether there has been a change in the video signal before the tracking projector. The signal change determination unit 1102 of the projector 110 acquires signal information by analyzing the video signal, and if there has been a change in the acquired signal information (step S405—YES), proceeds to step S406. If there has been no change in the signal information (step S405—NO), proceeds to step S404.

[0053] Here, for example, when a video signal is input from distributor 103 to projector 110 and video signal supply device 102 or distributor 103 starts outputting the video signal, if a transient phenomenon or the like occurs in video signal supply device 102 or distributor 103, a change may occur in at least one item (for example, horizontal resolution, vertical frequency, etc.) In this way, the video signal is not stable until a certain amount of time has passed since distributor 103 started outputting the video signal, and therefore it is determined that a change has occurred in the signal information.

[0054] When it is determined that there has been a change in the signal information, the match determination unit 1103 of the projector 110 determines whether the signal information has matched multiple times since it was determined that there had been a change in the video signal (step S406). Here, the video signal stabilizes after a certain amount of time has passed since the distributor 103 started outputting it, and no changes occur in the signal information. In step S405, the match determination unit 1103 determines, each time a determination timing arrives after it was determined that there had been a change in the video signal, whether the signal information of the video signal obtained at that determination timing is the same as the signal information obtained previously. If the signal information does not match multiple times (step S406—NO), the match determination unit 1103 executes step S406 again. If the signal information matches multiple times (step S406—YES), the process proceeds to step S407.

[0055] If it is determined that the signal information matches multiple times, the discrimination unit 1104 identifies the video signal by identifying a signal number corresponding to the signal information that matches multiple times (step S407). For example, the discrimination unit 1104 identifies signal information that matches the values ​​of each item included in the signal information that matches multiple times, by referring to a signal table stored in the storage unit 1110. The discrimination unit 1104 can then identify the signal number by reading out the signal number corresponding to the identified signal information. For example, if the horizontal frequency included in the signal information is "f12," the vertical frequency is "f22," and the values ​​of the other items match, the discrimination unit 1104 can identify the signal number as "0002."

[0056] Here, because there are many types of signal information, it may take some time to search the signal table and identify signal information from the signal table that matches the signal information obtained by analyzing the video signal. Here, the video signal is input first to the first projector 110 among the multiple projectors. Therefore, the projector 110 can start the signal discrimination process of step S407 at an earlier stage than the other projectors. Furthermore, as will be described later, the other projectors do not perform signal discrimination process, so there is no need to wait for the completion of the signal discrimination process that started later than the projector 110. This reduces the length of time it takes for the video to be displayed on the display screen.

[0057] Furthermore, the discrimination unit 1104 performs the signal discrimination process after determining that the signal information matches multiple times. Therefore, the signal discrimination process can be performed after the video signal has transitioned to a stable state. If the signal discrimination process is performed when a transient state occurs in the video signal at the stage when the output of the video signal starts, the accuracy of the signal discrimination process may decrease. However, the signal discrimination process can be performed after the video signal has transitioned to a stable state. Therefore, it is possible to prevent a decrease in the discrimination accuracy of the signal discrimination process.

[0058] When the signal number is identified, the discrimination unit 1104 outputs the identified signal number as the discrimination result.

[0059] Next, when the video signal is identified, the identification unit 1104 determines that there is no change in the signal information and outputs the determination that there is no change in the signal information to the first mute unit 1106 and the notification unit 1105. When the determination unit 1104 notifies the first mute unit 1106 of the determination, the first mute unit 1106 mutes the display of the video based on the video signal of the projector 110 based on the determination. The notification unit 1105 then notifies the other electronic devices (projectors 111, 112, and 113) of the determination result (signal number) and a mute instruction to mute the display of the video based on the video signal (step S408). Here, the projector 110 mutes the display of the video while transmitting a mute instruction to the projectors 111, 112, and 113, thereby muting the video in the projectors 111, 112, and 113 as well. This allows the images to be muted at the same timing in each of the projectors (110, 111, 112, 113). Because the timing at which the images are muted can be aligned for each projector, the sense of discomfort felt by a user viewing the display screen can be reduced compared to when the timing at which the images are muted differs for each projector.

[0060] Here, the processing of step S408 has been described as a case in which the video is muted after there is no change in the video signal and the signal number of the video signal has been determined. However, when it is determined in step S405 that there has been a change in the signal information, the first mute unit 1106 may mute the video display of projector 110, and the notification unit 1105 may send an instruction to other projectors (projectors 111, 112, 113) to mute the video display.

[0061] Next, when the determination result and the instruction to mute are transmitted, the determination unit 1104 determines the signal number of the video signal (step S409).

[0062] Once the signal number is determined, the first device setting unit 1107 performs settings for various devices provided in the projector 110 according to the signal number of the video signal in accordance with the determination result (step S410). For example, since the signal number has been identified, signal specifications corresponding to the signal number can be identified. Since the signal specifications can be identified, values ​​corresponding to the characteristics of the video signal, such as horizontal resolution, vertical resolution, horizontal frequency, vertical frequency, etc., corresponding to the signal specifications, are determined. As a result, the first device setting unit 1107 sets each device so that it can be driven to display according to the horizontal resolution, vertical resolution, horizontal frequency, vertical frequency, etc. corresponding to the signal specifications. The first device setting unit 1107 references the signal table, reads the signal specifications corresponding to the signal number, and sets each device according to the read signal specifications.

[0063] When the settings of the various devices are completed, the first setting completion notifying unit 1108 sets the mute flag assigned to the projector 110 itself from "1" to "0" (step S411). Setting the mute flag to "0" indicates that the device settings have been completed and that mute has been turned on. The first setting completion notifying unit 1108 transmits a notification indicating that the device settings have been completed to the other projectors (111, 112, 113) via a communication cable (step S412). Here, the first setting completion notifying unit 1108 may transmit an instruction to set the mute flag to "0" to notify that the settings have been completed.

[0064] Next, the first mute canceling unit 1109 determines whether or not a completion notification indicating that the device setting has been completed has been received from the other projectors (111, 112, 113) (step S413). If the first mute canceling unit 1109 receives the completion notification from the projector 111, it sets the mute flag assigned to the projector 111 among the mute flags stored in the projector 110 to "0." Similarly, if the first mute canceling unit 1109 receives the completion notification from the projector 112, it sets the mute flag assigned to the projector 112 among the mute flags stored in the projector 110 to "0." If the first mute canceling unit 1109 receives the completion notification from the projector 113, it sets the mute flag assigned to the projector 113 among the mute flags stored in the projector 110 to "0."

[0065] If at least one of the mute flags stored in the projector 110 is "1," the first mute canceling unit 1109 determines that there is a projector for which device setting has not been completed (step S413—NO) and executes the process of step S413 again after a certain waiting time has elapsed. On the other hand, if all of the mute flags stored in the projector 110 are "0," the first mute canceling unit 1109 determines that device setting has been completed for all of the multiple electronic devices (projectors 111, 112, and 113), including the projector 110 itself (step S413—YES). The first mute canceling unit 1109 then cancels the mute of the video display of the projector 110 (step S414). As a result, the projector 110 projects an image based on the video signal onto the display area 106 of the screen 105.

[0066] After unmuting the video display, projector 110 determines whether to end the process (step S415). If a power-off instruction or the like is input, projector 110 determines to end the process (step S415—YES) and ends the process. On the other hand, if projector 110 determines not to end the process (step S415—NO), it proceeds to step S401. In this case, if projector 110 determines in step S401 that it is the first projector, determines in step S404 that it has not received a determination result from another projector, and determines in step S405 that there is no change in the signal information of the video signal, it proceeds to step S404. Here, because there is no change in the signal information of the video signal, projector 110 maintains the settings for each device and can continue displaying video based on the video signal. On the other hand, if there is a change in the signal information of the video signal, the process proceeds to step S406, and the subsequent processes are executed, whereby each device is set according to the signal information of the video signal after the change, and a video based on the video signal is displayed. An example of a change in the video signal is when the video signal input from the video signal supply device 102 is switched to another video signal. Another example of a change in the video signal is when the video signal is switched to another video signal by a switcher.

[0067] Here, projector 110 waits for notifications of mute flag "0" to arrive from the other projectors (111, 112, 113). For example, when projector 111 among the other projectors completes device setting, it rewrites the mute flag assigned to projector 111 among the mute flags stored in projector 111 to "0". Then, projector 111 transmits notifications to projectors 110, 112, and 113 to set the mute flags to "0". When projector 110 receives a notification from projector 112 to set the mute flag to "0", projector 110 sets the mute flag assigned to projector 111 to "0". Similarly, projectors 112 and 113 transmit notifications to the other projectors to set their respective mute flags to "0" in response to the completion of device setting.

[0068] In this way, the projector 110 is unmuted based on all mute flags being updated to "0." Therefore, it is possible to unmute not only the projector 110 but also the other projectors (111, 112, 113) after confirming that device configuration is complete. As a result, when the video signal supply device 102 starts outputting a video signal, each projector can synchronize its timing to turn off the video display mute (unmute the video), thereby displaying the video based on the video signal in synchronized timing. When the video display mute is turned off, playback of the video signal also starts. Therefore, by synchronizing the timing at which the video display mute is turned off, the timing at which the video playback of the video based on the video signal starts can also be synchronized for each projector (110, 111, 112, 113). Therefore, even if images are projected individually from different projectors into each display area, the images displayed on the screen 105 can be viewed with synchronized playback timing as a whole.

[0069] Even if the timings at which the muting of the video display is released do not coincide perfectly between the projectors, the video based on the video signal can be displayed at roughly the same timing. Here, the display timing can be aligned to a degree that the viewer does not perceive a difference in the timing at which the video based on the video signal is displayed, so that the viewer is less likely to feel uncomfortable.

[0070] The operation of the projector 110 has been described above, and next, the operation of the projectors 111, 112, and 113 will be described. The operation of the projectors 111, 112, and 113 will also be described using the flowchart in Fig. 4. Here, of the projectors 111, 112, and 113, the operation of the projector 111 will be described, but the projectors 112 and 113 also operate according to a similar processing flow.

[0071] The projector 111 determines whether or not it is the first projector by referring to the number assigned to the terminal of the distributor 103 to which the projector 111 is connected (step S401). In this case, the projector 111 is connected to the second terminal 103b of the distributor 103 and is preset as the second projector, so it is determined that it is not the first projector (step S401-NO), and the process proceeds to step S402.

[0072] The mute notification determination unit 1113 of the projector 111 determines whether a mute notification has been received from another projector (step S402). Here, the projector 110 is executing the process of step S408 by the time the projector 111 executes the process of step S402. Therefore, the projector 110 has received from the projector 110 the result of the video signal determination and a mute instruction to mute the display of the video based on the video signal. As a result, the mute notification determination unit 1113 of the projector 111 determines that a mute instruction has been received (step S402—YES). On the other hand, if a mute instruction has not been received from another projector (step S402—NO), the mute notification determination unit 1113 executes the process of step S402 again after a certain waiting time has elapsed. In response to receiving the mute instruction from the projector 110, the mute processing unit 1114 mutes the display of the video signal (step S403).

[0073] The discrimination result determination unit 1115 of the projector 111 determines whether or not the discrimination result of the video signal has been received from another electronic device (the projector 110) (step S404). Here, the projector 110 is executing the process of step S408 by the time the projector 111 executes the process of step S404. Therefore, the discrimination result of the video signal and a mute instruction to mute the display of the video based on the video signal have been received from the projector 110. As a result, the discrimination result determination unit 1115 of the projector 111 determines that the mute instruction has been received (step S404—YES).

[0074] In response to the processing proceeding to step S410, the second device setting unit 1116 of the projector 111 performs settings for each device according to the type of video signal in accordance with the determination result received from the projector 110, without the determination processing of step S407 being performed in the projector 111 (step S410).

[0075] Here, if it is determined that a mute instruction has been received, projector 111 can proceed to step S410. That is, projectors other than projector 110 skip the processes from step S405 to step S409. Therefore, projectors other than projector 110 do not need to wait for the video signal to stabilize until the signal information matches multiple times in step S406. Furthermore, they only need to obtain a signal number from projector 110 without performing the signal discrimination process of step S407. Therefore, if each projector belonging to a multi-display system performs a process of waiting for the signal information to match multiple times or a process of signal discrimination, even if one projector has completed the signal information match determination or signal discrimination process, another projector may not have completed the process, lengthening the waiting time. This results in a problem: the time required to wait for the device settings to be completed in all projectors is extended, which lengthens the time until video mute is released, thereby lengthening the time until the video is displayed. In contrast, with the above-described multi-display system S, instead of all projectors performing the signal information match determination and signal discrimination process, the first projector performs the process and notifies the other projectors of the results. This allows the system to proceed to the setting process for each device in step S410 without waiting for the other projectors to complete the signal information match determination and signal discrimination process. This reduces the time it takes to display an image based on a video signal.

[0076] When the settings of the various devices are completed, the second setting completion notifying unit 1117 of the projector 111 sets the mute flag assigned to the projector 111 itself from "1" to "0" (step S411). The second setting completion notifying unit 1117 of the projector 111 also transmits a notification indicating that the device settings have been completed to the other projectors (110, 112, 113) via the communication cable (step S412). Here, the first setting completion notifying unit 1108 may transmit an instruction to set the mute flag to "0" to notify that the settings have been completed.

[0077] Next, second mute canceling unit 1118 of projector 111 determines whether or not a completion notification indicating that the device setting has been completed has been received from the other projectors (110, 112, 113) (step S413). If second mute canceling unit 1118 receives the completion notification from projector 110, it sets the mute flag assigned to projector 110 among the mute flags stored in projector 111 to "0." Similarly, if second mute canceling unit 1118 receives the completion notification from projector 112, it sets the mute flag assigned to projector 112 among the mute flags stored in projector 110 to "0." If second mute canceling unit 1118 receives the completion notification from projector 113, it sets the mute flag assigned to projector 113 among the mute flags stored in projector 110 to "0."

[0078] If at least one of the mute flags stored in the projector 111 is "1," the second mute canceling unit 1118 of the projector 111 determines that there is a projector for which device setting has not been completed (step S413—NO) and executes the process of step S413 again after a certain waiting time has elapsed. On the other hand, if all of the mute flags stored in the projector 111 are "0," the second mute canceling unit 1118 of the projector 111 determines that device setting has been completed for all of the multiple electronic devices (projectors 110, 112, and 113), including the projector 111 itself (step S413—YES). The second mute canceling unit 1118 then cancels the mute of the video display of the projector 111 (step S414). As a result, the projector 111 projects an image based on the video signal onto the display area 108 of the screen 105.

[0079] After unmuting the video display, projector 111 determines whether to end the process (step S415). If a power-off instruction or the like is input, projector 111 determines to end the process (step S415—YES) and ends the process. On the other hand, if projector 111 determines not to end the process (step S415—NO), it proceeds to step S401. In this case, if projector 111 determines in step S401 that it is not the first projector and has not received a mute instruction from another projector in step S402 (step S402—NO), it executes the process of step S402 again after a certain waiting time has elapsed. On the other hand, if projector 111 has received a mute instruction from another projector (step S402—YES), it mutes the display of the video signal in response to receiving the mute instruction from projector 110 (step S403). The projector 111 then determines whether it has received a video signal discrimination result from another projector. If the projector 111 has not received a video signal discrimination result from another projector and there is no change in the video signal (step S405—NO), the process proceeds to step S404. Here, since there is no change in the signal information of the video signal, the projector 111 maintains the settings for each device and continues displaying images based on the video signal. If there is a change in the signal information of the video signal and the projector 111 receives a mute instruction or a video signal discrimination result from another projector, the process proceeds as described above. Furthermore, if the projector 111 detects a signal change in step S405 (step S405—YES), the process proceeds to step S406, where it performs a video signal match determination and video signal discrimination process, thereby notifying the other projectors (110, 112, 113) of the mute instruction and the discrimination result. In this case, the other projectors (110, 112, 113) receive the mute instruction and the determination result from the projector 111, mute the video display, and can set each device based on the determination result.

[0080] The operation of the projector 111 has been described above, but the projector 112 also executes the same processing as the projector 112 while communicating with the other projectors (110, 111, 113). The projector 113 also executes the same processing as the projector 112 while communicating with the other projectors (110, 111, 112).

[0081] In the above-described embodiment, notifications from one projector to another projector may be sent individually by specifying the destination projector, or may be sent simultaneously to the other projectors.

[0082] Next, FIG. 5 shows the states of the mute flags of projectors 110 to 113. In this figure, the horizontal direction represents the states of the mute flags for projectors 110 to 113, and the vertical direction represents the passage of time. Each projector can store four mute flags (flag F0, flag F1, flag F2, and flag F3). Flag F0 indicates the state of the mute flag assigned to projector 110, flag F1 indicates the state of the mute flag assigned to projector 111, flag F2 indicates the state of the mute flag assigned to projector 112, and flag F3 indicates the state of the mute flag assigned to projector 113. These mute flags may be stored in storage unit 1110.

[0083] Time t1 (first row) represents the initial state, and flags F0 to F3 are all "1" in all of projectors 110 to 113. In the initial state, no video signal is supplied from distributor 103, and the setting of each device is not yet complete.

[0084] Then, when projector 110 first executes the process up to step S411, at time t2 (second row), among the mute flags stored in projector 110, the flag assigned to projector 110 is set to "0" (reference numeral 20). At this stage, it indicates that only projector 110 has completed device setting. Then, when projector 110 transmits a completion notification to the other projectors (111, 112, 113) in step S412, at time t3, projectors 111, 112, 113 set the flag assigned to projector 110 to "0" (reference numerals 31, 32, 33) based on this notification. Here, in projector 110, the flag assigned to projector 110 is maintained at "0". Thereafter, in each projector, each device is set based on the determination result output from projector 110, and a completion notification is transmitted, so that at time t4, the flags of each projector (110, 111, 112, 113) are all set to "0" (reference numerals 40, 41, 42, 43). As a result, the mute of the video display is released in each projector (110, 111, 112, 113).

[0085] In the first embodiment described above, after EDID information is exchanged between the video signal supply device 102 and the distributor 103, the EDID information is exchanged between the distributor 103 and the first projector, and a video signal is supplied from the distributor 103 to the projector 110. Thereafter, EDID information is exchanged between the distributor 103 and the second projector 111, and a video signal is supplied from the distributor 103 to the second projector 111. After this, EDID information is exchanged and a video signal is supplied in the order of the distributor 103 and the third projector 112, and the distributor 103 and the fourth projector 113. Here, the first projector 110 performs a video signal discrimination process in parallel with the processes of the other projectors (111, 112, 113) exchanging EDID signals with the distributor 103 and supplying video signals, and can notify the other projectors (111, 112, 113) of the discrimination results. As a result, the other projectors (111, 112, 113) can obtain the video signal discrimination result from projector 110 even before or during the exchange of EDID information with distributor 103, before starting the process of discriminating the type of video signal, etc. As a result, even when a process that requires a certain amount of time, such as the exchange of EDID signals, is performed sequentially for each projector, by sharing the video signal discrimination result, it is not necessary for the second or subsequent projectors (111, 112, 113) to perform the signal discrimination process and wait for the discrimination result to be obtained. Therefore, the time from when the video signal is supplied from video signal supply device 102 to when the mute of the video display is released can be shortened.

[0086] In the above-described embodiment, the projector 110 is set as the first projector by being connected to the first terminal 103a, and the projector 111 is set as the second or subsequent projector by being connected to the second terminal 103b, the projector 112 is set as the third terminal 103c, and the projector 113 is set as the fourth terminal 103d. Here, the projector 110 may be connected to a terminal other than the first terminal 103a. For example, the projector 110 may be connected to any one of the second terminal 103b, the third terminal 103c, and the fourth terminal 103d. In this case, the projector 110 determines that it is the second or subsequent projector and executes processing by the second function unit 110B, thereby functioning as the second or subsequent projector. Furthermore, any one of the projectors 111, 112, and 113 may be connected to the first terminal 103a. In this case, the projector connected to the first terminal 103a is determined to be the first projector, and can function as the first projector by having the first function unit 110A execute processing.

[0087] Next, Fig. 6 is a schematic diagram showing the configuration of a multi-display system Sa according to a second embodiment. In the multi-display system S in Fig. 1, a distributor 103 is connected between the video signal supply device 102 and each projector, and multiple projectors are connected in parallel to this distributor 103. However, in the multi-display system Sa shown in Fig. 6, the projectors are daisy-chained without using a distributor. In the multi-display system Sa, the projectors are connected in series. That is, the projectors are daisy-chained.

[0088] In the multi-display system Sa, the display device 301 is connected to an input terminal of a video signal supply device 302 via a communication cable. The video signal supply terminal of the video signal supply device 302 is connected to a connection terminal of the projector 310 via a communication cable. This communication cable may be an HDMI (registered trademark) cable. The video signal supply device 302 acquires EDID information from the projector 310 via the HDMI (registered trademark) cable, and outputs a video signal corresponding to the optimal resolution of the projector 310 to the projector 310 based on the acquired EDID signal.

[0089] The remote control 304 wirelessly transmits a control signal and a switching signal to each of the projectors (projector 310, projector 311, projector 312, and projector 313). The control signal is a signal that turns the power on or off. The switching signal is a signal that switches which device receives the video signal.

[0090] An input terminal 315 of the projector 310 is not connected to other electronic devices (projectors 311, 312, 313, etc.). An output terminal 316 of the projector 310 is connected to an input terminal 318 of the projector 311 via a communication cable. This communication cable can be a communication cable (e.g., a LAN cable) capable of communicating signals based on HDBaseT. An output terminal 319 of the projector 311 is connected to an input terminal 321 of the projector 312 via a communication cable (e.g., a LAN cable).

[0091] An output terminal 322 of the projector 312 is connected via a communication cable (e.g., a LAN cable) to an input terminal 324 of the projector 313. Although it is possible to connect another projector to an output terminal 325 of the projector 313 via a communication cable (e.g., a LAN cable), no other projector is connected here.

[0092] Input terminal 317 of projector 311, input terminal 320 of projector 312, and input terminal 323 of projector 313 can each be connected to a video signal supply device or a distributor via a communication cable (e.g., an HDMI (registered trademark) cable), but nothing is connected here.

[0093] Projectors 310 and 311, projectors 311 and 312, and projectors 312 and 313 are connected in series by LAN cables, and video signals are transmitted using HDBaseT-based signals. For example, projector 310 converts a video signal input from video signal supply device 302 via an HDMI (registered trademark) cable into an HDBaseT signal within projector 310 and outputs the converted signal from output terminal 316, which is HDBaseT-OUT. As a result, the video signal output from projector 310 is input to input terminal 317, which is HDBaseT-IN, of projector 311. Such video signal supply is performed similarly between projectors 311 and 312 and between projectors 312 and 313. In addition, between each projector, notifications of the determination results, mute instructions, notifications indicating that device settings have been completed, etc. can be communicated between the four projectors in both directions by communicating via this LAN cable.

[0094] Here, each projector (310, 311, 312, 313) is assigned a different number in advance. By recognizing its number, each projector identifies whether it is the first projector (first electronic device) or a second or subsequent projector (second electronic device, third electronic device, fourth electronic device). Furthermore, a correspondence between the number and the display area to be projected—display area 106, display area 107, display area 108, or display area 109—is predetermined, and recognizing the number determines which display area the image will be projected onto. Furthermore, since each projector has the same specifications, video signal supply device 302 acquires EDID information from projector 310 and outputs a video signal with a resolution corresponding to the EDID information to projector 310. This allows projectors 311, 312, and 313 to acquire video signals with optimal resolutions.

[0095] Screen 305 displays images by projecting them from each projector (projector 310, projector 311, projector 312, projector 313). Screen 305 is divided into two sections each in the vertical and horizontal directions. Screen 305 is divided into a total of four display areas, namely, display area 306, display area 307, display area 308, and display area 309, which are installed adjacent to each other. Display area 306 is assigned as the area onto which an image is projected by projector 310. Display area 307 is assigned as the area onto which an image is projected by projector 311. Display area 308 is assigned as the area onto which an image is projected by projector 312. Display area 309 is assigned as the area onto which an image is projected by projector 313.

[0096] In the above-described multi-display system Sa, the processes of the projectors 310, 311, 312, and 313 can be performed in the same manner as the processes shown in the flowchart of FIG.

[0097] In the above-described embodiment, the projector 310 is pre-assigned as the first projector and functions as the first projector. Also, the projectors 311, 312, and 313 are assigned numbers from second to fourth, and function as the second and subsequent projectors. However, the settings may be changed so that one of the projectors 311, 312, and 313 is assigned as the first projector, and the remaining projectors are assigned as the second and subsequent projectors. In this case, any one of the projectors 311, 312, and 313 assigned as the first projector can be determined to be assigned as the first projector and can function as the first projector by executing processing by the first function unit 110A. Furthermore, when projector 310 is assigned as one of the second to fourth projectors, it determines that it has been assigned as the second or subsequent projector, and can function as the second or subsequent projector by executing processing by second function unit 110B.

[0098] According to the multi-display system S in the first embodiment and the multi-display system Sa in the second embodiment described above, by notifying signal information and signal numbers from one projector to other projectors, it is possible to shorten the time from when a video signal is input to when the video display of each projector is unmuted.

[0099] FIG. 7 is a schematic diagram showing the configuration of a multi-display system Sb according to a third embodiment. The multi-display system Sb includes a plurality of electronic devices that display images based on video signals. The plurality of electronic devices include first to Nth electronic devices (N is a natural number equal to or greater than 2). In this multi-display system Sb, a projector 500, which is a first electronic device, and a projector 511, which is a second electronic device, are communicatively connected via a communication cable. While the multi-display system Sb is shown having two projectors, projector 500 and projector 511, it may also have three or more projectors. In a case where three or more projectors are included, the third and subsequent projectors may be connected to projector 500 via a communication cable so as to be in parallel with projector 511. The third and subsequent projectors may also be connected in series to projector 511. A distributor may also be connected to the video signal supply device, and the multiple projectors may be connected in parallel to the distributor. Furthermore, a video signal is supplied to each of the plurality of electronic devices.

[0100] Projector 511 is an electronic device other than the first electronic device and is a follow-up electronic device. Projector 511 has a communication unit 5111 and a first function unit 510A. First function unit 510A has a mute notification determination unit 5113, a mute processing unit 5114, a discrimination result determination unit 5115, a second device setting unit 5116, a second setting completion notification unit 5117, and a second mute cancellation unit 5118. Communication unit 5111 is connected to an external device (e.g., a projector) via a communication cable and communicates with the connected device. Mute notification determination unit 5113 determines whether a mute notification for muting the display of a video based on a video signal has been received from any electronic device other than the projector itself.

[0101] The mute processing unit 5114 performs video mute processing in response to receiving a mute notification from any electronic device other than the primary electronic device. The discrimination result determination unit 5115 determines whether the discrimination result for the video signal has been received from any electronic device other than the primary electronic device. The second device setting unit 5116 receives the discrimination result from a first electronic device among the electronic devices other than the primary electronic device, and sets each device related to the video signal-based video display processing in the secondary electronic device according to the type of video signal in accordance with the discrimination result received from the first electronic device, without performing discrimination processing to discriminate the video signal input to the secondary electronic device. The second setting completion notification unit 5117, upon completion of device setting processing, sends a notification indicating completion of setting to each electronic device other than the primary electronic device.

[0102] The second mute canceling unit 5118 receives a notification from each electronic device indicating that the setting has been completed, and when the device setting has been completed for all of the plurality of electronic devices, including the target electronic device, the second mute canceling unit 5118 cancels the video mute of the target electronic device and causes the display unit to display the video based on the video signal. The display unit is, for example, a screen. When the second mute canceling unit 5118 cancels the video mute, the projector 511 displays the video based on the video signal by projecting it onto the screen.

[0103] The projector 500 is a first electronic device and is a leading electronic device. The projector 500 has a communication unit 5101 and a second function unit 510B. The second function unit 510B has a signal change determination unit 5102, a match determination unit 5103, a discrimination unit 5104, a notification unit 5105, a first mute unit 5106, a first device setting unit 5107, a first setting completion notification unit 5108, and a first mute release unit 5109. The communication unit 5101 is connected to an external device (e.g., a projector) via a communication cable and communicates with the connected device.

[0104] The signal change determination unit 5102 determines whether or not there has been a change in the video signal input to the self-led electronic device before there has been a change in the video signal input to the self-led electronic device, without determining whether or not a mute notification for muting the display of video based on the video signal has been received from any electronic device other than the self-led electronic device. After it has been determined that there has been a change in the video signal based on the determination result of the signal change determination unit 5102, when there is no change in the video signal, the determination unit 5104 performs a determination on the video signal input to the self-led electronic device.

[0105] When the video signal is identified by the identification unit 5104, the notification unit 5105 notifies each electronic device other than the main electronic device of the identification result and a mute instruction to mute the display of video based on the video signal. The first mute unit 5106 mutes the display of video based on the video signal in the main electronic device in response to the video signal identification by the identification unit 5104. When the identification result is obtained by the identification unit 5104, the first device setting unit 5107 performs setting according to the type of the video signal for each device related to the display processing of video based on the video signal in the main electronic device based on the identification result.

[0106] When the device setting process is completed, the first setting completion notifying unit 5108 sends a notification indicating that the setting is complete to each of the electronic devices other than the main electronic device. The first mute canceling unit 5109 receives a notification indicating that the setting is complete from each electronic device, and when the device setting is complete for all of the plurality of electronic devices, including the main electronic device, cancels the video mute of the main electronic device and displays the video based on the video signal on the display unit. The display unit is, for example, a screen. When the video mute is canceled by the first mute canceling unit 5109, the projector 500 displays the video based on the video signal by projecting it onto the screen.

[0107] In the first and second embodiments described above, the storage unit 1110 is configured by a storage medium such as a hard disk drive (HDD), flash memory, electrically erasable programmable read-only memory (EEPROM), random access read / write memory (RAM), read-only memory (ROM), or any combination of these storage media. This storage unit 1110 can be, for example, a nonvolatile memory.

[0108] The communication unit 1100, the control unit 1101, the first functional unit 110A, and the second functional unit 110B in the first and second embodiments may be configured by a processing unit such as a CPU (Central Processing Unit) or a dedicated electronic circuit. The first functional unit 510A and the second functional unit 510B in the third embodiment may be configured by a processing unit such as a CPU or a dedicated electronic circuit.

[0109] 2, the programs for realizing the functions of the communication unit 1100, the control unit 1101, the first function unit 110A, and the second function unit 110B, and the programs for realizing the functions of the communication unit 5101, the first function unit 510A, and the communication unit 5111, and the second function unit 510B in FIG. 7 may be recorded on a computer-readable recording medium, and the programs recorded on this recording medium may be read into a computer system and executed to perform construction management. Note that the term "computer system" here includes hardware such as an OS and peripheral devices.

[0110] Furthermore, if a WWW system is used, the term "computer system" also includes the homepage provision environment (or display environment). Furthermore, "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into computer systems. Furthermore, "computer-readable recording medium" also includes devices that retain programs for a certain period of time, such as volatile memory within a computer system that serves as a server or client. The program may be one that realizes part of the aforementioned functions, or it may be one that realizes the aforementioned functions in combination with a program already stored in the computer system. The program may also be stored on a designated server, and distributed (e.g., downloaded) via a communication line in response to requests from other devices.

[0111] Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope of the gist of the present invention.

[0112] 10...Video signal supply device, 12...Projector, 101...Display device, 102...Video signal supply device, 103...Distributor, 103a...First terminal, 103b...Second terminal, 103c...Third terminal, 103d...Fourth terminal, 104...Remote control, 105...Screen, 106...Display area, 107...Display area, 108...Display area, 109...Display area, 110...Projector, 110A...First function unit, 110B...Second function unit, 111...Projector, 112...Projector, 113...Projector, 114...Input terminal, 115...Input terminal, 116...Output terminal, 117...Input terminal terminal, 118...input terminal, 119...output terminal, 120...input terminal, 121...input terminal, 122...output terminal, 123...input terminal, 124...input terminal, 125...output terminal, 301...display device, 302...video signal supply device, 304...remote control, 305...screen, 306...display area, 307...display area, 308...display area, 309...display area, 310...projector, 311...projector, 312...projector, 313...projector, 315...input terminal, 316...output terminal, 317...input terminal, 318...input terminal, 319...output terminal, 320...input terminal , 321...input terminal, 322...output terminal, 323...input terminal, 324...input terminal, 325...output terminal, 500...projector, 510A...first function unit, 510B...second function unit, 511...projector, 1100...communication unit, 1101...control unit, 1102...signal change determination unit, 1103...match determination unit, 1104...discrimination unit, 1105...notification unit, 1106...first mute unit, 1107...first device setting unit, 1108...first setting completion notification unit, 1109...first mute release unit, 1110...storage unit, 1113...mute notification determination unit, 1114...mute processing unit, 11 15...discrimination result determination unit, 1116...second device setting unit, 1117...second setting completion notification unit, 1118...second mute release unit, 1555...device, 2555...system, 5101...communication unit, 5102...signal change determination unit, 5103...match determination unit, 5104...discrimination unit, 5105...notification unit, 5106...first mute unit, 5107...first device setting unit, 5108...first setting completion notification unit, 5109...first mute release unit, 5111...communication unit, 5113...mute notification determination unit, 5114...mute processing unit, 5115...discrimination result determination unit, 5116...second device setting unit,5117...second setting completion notification unit, 5118...second mute release unit, S...multi-display system, Sa...multi-display system, Sb...multi-display system,

Claims

1. A multi-display system including a plurality of electronic devices that display images based on a video signal, the plurality of electronic devices being numbered first through Nth (N being a natural number of 2 or more), and each electronic device being supplied with a video signal, the follow-up electronic devices being other than the first electronic device each having: a mute notification determination unit that determines whether a mute notification for muting the display of an image based on the video signal has been received from any electronic device other than the first electronic device; a mute processing unit that performs video muting processing in response to receiving a mute notification from any electronic device other than the first electronic device; a determination result determination unit that determines whether a determination result for determining the video signal has been received from any electronic device other than the first electronic device; a second device setting unit that, upon receiving a determination result from the first electronic device among the electronic devices other than the first electronic device, sets each device related to the display processing of the image based on the video signal in the first electronic device according to the type of the video signal in accordance with the determination result received from the first electronic device, without performing a determination process for determining the video signal input to the first electronic device; and a second setting completion notification unit that, upon completion of the setting process for the device, transmits a notification indicating that the setting has been completed to each electronic device other than the first electronic device. a second mute release unit that receives from each electronic device a notification indicating that the setting has been completed, and when the device setting of all of the plurality of electronic devices including the main electronic device has been completed, releases the video mute of the main electronic device and displays the video based on the video signal on the display unit, wherein the main electronic device has: a signal change determination unit that determines whether or not there has been a change in the video signal input to the main electronic device without determining whether or not a mute notification to mute the display of the video based on the video signal has been received from any electronic device other than the main electronic device; a determination unit that determines whether or not there has been a change in the video signal input to the main electronic device based on the determination result of the signal change determination unit; and a notification unit that, when the video signal has been determined by the determination unit, notifies each electronic device other than the main electronic device of the determination result and a mute instruction to mute the display of the video based on the video signal.a first muting unit which mutes the display of a video based on the video signal of the main electronic device in response to the discrimination of the video signal by the discrimination unit; a first device setting unit which, when a discrimination result is obtained by the discrimination unit, sets each device related to a display process of a video based on a video signal in the main electronic device according to the type of the video signal based on the discrimination result; a first setting completion notifying unit which, when the setting process of the device is completed, sends a notification indicating that the setting is completed to each electronic device other than the main electronic device; and a first mute release unit which receives the notification indicating that the setting is completed from each electronic device, and when device setting is completed for all of the plurality of electronic devices including the main electronic device, releases the video mute of the main electronic device and causes the video based on the video signal to be displayed on a display unit.

2. The signal change determination unit of the leading electronic device analyzes the video signal, acquires signal information relating to the video signal based on the analysis result, and determines that there has been a change in the video signal if there is a change in the acquired signal information; the leading electronic device has a match determination unit that determines whether the signal information matches multiple times after it is determined that there has been a change in the video signal based on the judgment result of the signal change determination unit; and the discrimination unit of the leading electronic device discriminates the video signal input to the main electronic device if the match determination unit determines that there has been a match multiple times.

3. The multi-display system according to claim 1, wherein the discrimination unit of the leading electronic device identifies identification information corresponding to signal information of a video signal, and outputs the identified identification information as a discrimination result.

4. The multi-display system according to claim 1, wherein whether or not an electronic device is the first electronic device among the first to Nth electronic devices is set in advance.

5. The multi-display system described in claim 1, wherein each of the first to Nth electronic devices has both a function as the trailing electronic device and a function as the leading electronic device, and when any one electronic device is designated as the first electronic device, the electronic device designated as the first electronic device functions as the leading electronic device, and the electronic devices not designated as the first electronic device function as the trailing electronic devices.

6. A multi-display system including a plurality of electronic devices that display images based on a video signal, the plurality of electronic devices include first to Nth electronic devices (N is a natural number of 2 or more), and a video signal is supplied to each of the electronic devices. The follow-up electronic devices other than the first electronic device include: a mute notification determination unit that determines whether a mute notification for muting the display of an image based on the video signal has been received from any electronic device other than the first electronic device; a mute processing unit that performs video mute processing in response to receiving a mute notification from any electronic device other than the first electronic device; a determination result determination unit that determines whether a determination result of determining the video signal has been received from any electronic device other than the first electronic device; a second device setting unit that receives a determination result from the first electronic device among the electronic devices other than the first electronic device, and sets each device related to the display processing of the image based on the video signal in the follow-up electronic device according to the type of the video signal in accordance with the determination result received from the first electronic device without performing a determination process of determining the video signal input to the follow-up electronic device; and a second setting completion notification unit that transmits a notification indicating that the setting has been completed to each electronic device other than the first electronic device when the setting process of the device is completed. a second mute release unit that receives a notification from each electronic device indicating that the setting has been completed, and when device setting has been completed for all of the plurality of electronic devices including the following electronic device, releases the video mute of the following electronic device and causes a video based on the video signal to be displayed on a display unit.

7. A multi-display system including a plurality of electronic devices that display images based on video signals, the plurality of electronic devices include first to Nth electronic devices (N is a natural number equal to or greater than 2), and a video signal is supplied to each of the electronic devices. The first electronic device, a leading electronic device, includes: a signal change determination unit that determines whether or not there has been a change in the video signal input to the leading electronic device, without determining whether or not a mute notification for muting the display of the video based on the video signal has been received from any electronic device other than the leading electronic device; a determination unit that determines whether or not there has been a change in the video signal input to the leading electronic device based on the determination result of the signal change determination unit; a notification unit that, when the video signal is determined by the determination unit, notifies each electronic device other than the leading electronic device of the determination result and a mute instruction for muting the display of the video based on the video signal; and a first mute unit that mutes the display of the video based on the video signal of the leading electronic device in response to the determination of the video signal by the determination unit. a first device setting unit which, when a determination result is obtained by the determination unit, sets each device related to a display process of an image based on a video signal in the self-led electronic device according to the type of the video signal in accordance with the determination result; a first setting completion notifying unit which, when the setting process of the device is completed, sends a notification indicating that the setting is completed to each electronic device other than the self-led electronic device; and a first mute release unit which receives the notification indicating that the setting is completed from each electronic device, and, when device setting is completed for all of the plurality of electronic devices including the self-led electronic device, releases video mute of the self-led electronic device and displays the image based on the video signal on a display unit.

8. A display method in a multi-display system including a plurality of electronic devices that display video based on a video signal, the plurality of electronic devices include first to Nth electronic devices (N is a natural number equal to or greater than 2), and a video signal is supplied to each of the plurality of electronic devices; and in a follow-up electronic device other than the first electronic device, a mute notification determination unit determines whether a mute notification for muting the display of a video based on the video signal has been received from any electronic device other than the first electronic device; a mute processing unit performs video muting processing in response to receiving a mute notification from any electronic device other than the first electronic device; a discrimination result determination unit determines whether a discrimination result for discriminating the video signal has been received from any electronic device other than the first electronic device; and a second device setting unit receives the discrimination result from the first electronic device among the electronic devices other than the first electronic device, and sets each device related to the display processing of the video based on the video signal in the first electronic device according to the type of the video signal without performing discrimination processing for discriminating the video signal input to the first electronic device, a second setting completion notifying unit, when the setting process of the device is completed, sends a notification indicating that the setting is completed to each of the electronic devices other than the main electronic device; a second mute canceling unit receives a notification indicating that the setting is completed from each electronic device, and when the device setting of all of the plurality of electronic devices including the main electronic device is completed, cancels the video mute of the main electronic device and displays the video based on the video signal on the display unit; in the lead electronic device which is the first electronic device, a signal change determining unit determines whether or not there has been a change in the video signal input to the main electronic device prior to the trailing electronic device, without determining whether or not a mute notification for muting the display of the video based on the video signal has been received from any of the electronic devices other than the main electronic device; a discrimination unit, after it is determined that there has been a change in the video signal based on the determination result of the signal change determining unit, discriminates the video signal input to the main electronic device; and when the video signal is discriminated by the discrimination unit, notifies each of the electronic devices other than the main electronic device of the discrimination result and a mute instruction for muting the display of the video based on the video signal,a first muting unit mutes the display of a video based on the video signal of the main electronic device in response to the discrimination of the video signal by the discrimination unit; a first device setting unit, when a discrimination result is obtained by the discrimination unit, sets each device related to the display processing of the video based on the video signal in the main electronic device according to the type of the video signal based on the discrimination result; a first setting completion notification unit, when the setting processing of the device is completed, sends a notification indicating that the setting is completed to each electronic device other than the main electronic device; and a first mute release unit receives a notification indicating that the setting is completed from each electronic device, and when device setting is completed for all of the plurality of electronic devices including the main electronic device, releases the video mute of the main electronic device and displays the video based on the video signal on a display unit.

9. The display method according to claim 8, wherein each of the first to Nth electronic devices has both a function as the follower electronic device and a function as the lead electronic device, and when any one electronic device is designated as the first electronic device, the electronic device designated as the first electronic device functions as the lead electronic device, and the electronic devices not designated as the first electronic device function as the follower electronic devices.

10. A multi-display system including a plurality of electronic devices that display images based on a video signal, the plurality of electronic devices include first to Nth electronic devices (N is a natural number equal to or greater than 2), and a video signal is supplied to each of the electronic devices; a follow-up electronic device other than the first electronic device has a mute notification determination unit that determines whether or not a mute notification for muting the display of an image based on the video signal has been received from any electronic device other than the first electronic device; a mute processing unit that performs an image mute process in response to receiving a mute notification from any electronic device other than the first electronic device; a discrimination result determination unit that determines whether or not a discrimination result for discriminating the video signal has been received from any electronic device other than the first electronic device; and a second device setting unit that receives the discrimination result from the first electronic device among the electronic devices other than the first electronic device, and sets each device related to the display process of the image based on the video signal in the follow-up electronic device according to the type of the video signal in accordance with the discrimination result received from the first electronic device without performing a discrimination process for discriminating the video signal input to the follow-up electronic device; A display method in which, when the setting process of the device is completed, a second setting completion notification unit sends a notification indicating that the setting has been completed to each electronic device other than the main electronic device, and a second mute release unit receives a notification indicating that the setting has been completed from each electronic device, and when device setting of all of the plurality of electronic devices including the main electronic device has been completed, releases video mute of the main electronic device and displays video based on the video signal on a display unit.

11. A multi-display system including a plurality of electronic devices that display images based on video signals, the plurality of electronic devices include first to Nth electronic devices (N is a natural number equal to or greater than 2), and a video signal is supplied to each of the electronic devices; the first electronic device, which is a leading electronic device, has a signal change determination unit that determines whether or not there has been a change in the video signal input to the leading electronic device before the electronic devices other than the leading electronic device, without determining whether or not a mute notification for muting the display of the video based on the video signal has been received from any electronic device other than the leading electronic device; a discrimination unit that discriminates the video signal input to the leading electronic device after it has been determined that there has been a change in the video signal based on the judgment result of the signal change determination unit; a notification unit that, when the video signal is discriminated by the discrimination unit, notifies each electronic device other than the leading electronic device of the discrimination result and a mute instruction for muting the display of the video based on the video signal; and a first mute unit that mutes the display of the video based on the video signal of the leading electronic device in response to the discrimination of the video signal by the discrimination unit. A display method in which, when a discrimination result is obtained by the discrimination unit, a first device setting unit sets each device related to the display processing of video based on a video signal in the self-led electronic device according to the discrimination result, in accordance with the type of the video signal; when the setting processing of the device is completed, a first setting completion notification unit sends a notification indicating that the setting is completed to each electronic device other than the self-led electronic device; and a first mute release unit receives a notification indicating that the setting is completed from each electronic device, and when device setting is completed for all of the plurality of electronic devices including the self-led electronic device, releases the video mute of the self-led electronic device and displays the video based on the video signal on a display unit.

Images