Video display device, video display system, and brightness adjustment method for video display device

Abstract

To uniform the characteristics of each display screen when an image for one screen portion comprising a plurality of display screens by using a plurality of image display devices.SOLUTION: An image display device is a master image display device which configures a multi-display device connected with the other image display device in a loop shape, and includes: an image feature data extraction part for extracting first image feature data from a received image signal; a controller for generating a common setting value for controlling a light source and controlling the light source of an own device on the basis of the common setting value: a data input part for inputting second image feature data from the other device of the previous stage; and a data output part for outputting the first image feature data or the common setting value to the other device of the subsequent stage. The controller outputs the extracted first video feature data to the other image display device of the subsequent stage, and after that, calculates the common image setting value on the basis of the inputted second image feature data, and outputs the common image setting value to the other image display device of the subsequent stage.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a video display device that is used in plurality to configure a multi-display device that displays a single screen's worth of video on a plurality of display screens. [Background technology]

[0002] Patent Document 1 discloses a device that controls the amount of light in multiple video display devices in conjunction with an input video signal. This device includes a means for detecting the characteristics of the input video signal and a control means for controlling the amount of light based on the detected characteristics, and is characterized in that the characteristic detection means receives the same video signal as that input to other video display devices. This makes it possible to dynamically change the light control of multiple video display devices in the same way, thereby realizing a display screen with a sense of unity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-178772 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure prevents a viewer from feeling uncomfortable due to unevenness in the characteristics of each display screen when a multi-display device consisting of multiple image display devices is used to create an image for one screen consisting of multiple display screens. [Means for solving the problem]

[0005] The video display device disclosed herein is a master video display device that is connected in a loop with other slave video display devices to form a multi-display type video display system that displays one screen's worth of video on multiple display screens, and is equipped with a light source, a light source control unit that controls the light source, a display element that generates video light that forms a display screen by modulating light from the light source based on a video signal, a video signal receiving unit that receives the video signal, a video feature data extraction unit that extracts first video feature data that indicates characteristics of the video signal from the video signal received by the video signal receiving unit, a controller that generates a common video setting value for controlling the light sources in its own device and the other video display devices and further controls the light source of its own device based on the common video setting value, a data input unit that inputs second video feature data that indicates characteristics of the video signal for each of its own device and the other video display devices from the other video display devices in the previous stage, and a data output unit that outputs the first video feature data or the common video setting value to the other video display devices in the subsequent stage. The controller outputs the first image feature data extracted by the image feature data extraction unit to another image display device in a downstream stage, and then, when second image feature data is input, calculates a common image setting value based on the input second image feature data, and outputs the calculated common image setting value to the other image display device in a downstream stage.

[0006] Another image display device in the present disclosure is a slave image display device that is connected in a loop with a master image display device to form a multi-display type image display system that displays one screen's worth of image using multiple display screens, and is equipped with a light source, a light source control unit that controls the light source, a display element that generates image light that forms a display screen by modulating light from the light source based on a video signal, a video signal receiving unit that receives the video signal, a video feature data extraction unit that extracts first image feature data that indicates characteristics of the video signal from the video signal received by the video signal receiving unit, a data input unit that inputs second image feature data that indicates characteristics of the video signal for the other image display device in the previous stage, or a common image setting value for controlling the light source of the own device and the other image display device, a controller that calculates third image feature data and further controls the light source of the own device based on the common image setting value, and a data output unit that outputs the third image feature data or the common image setting value to the other image display device in the subsequent stage. When the controller receives second image feature data from another image display device in the preceding stage, it generates third image feature data from the first image feature data and the second image feature data, outputs the generated third image feature data to another display device in the following stage, and then, when it receives a common image setting value from another image display device in the preceding stage, it outputs the input common image setting value to another display device in the following stage.

[0007] The video display system according to the present disclosure is a multi-display type video display system that displays one screen's worth of video on a plurality of display screens, and includes a master video display device and a slave video display device connected in a loop by connecting each other's data input unit and data output unit with a signal line. The master video display device includes a first video feature data extraction unit that extracts first video feature data indicating characteristics of a video signal from a received video signal, a first controller that generates common video setting values ​​for controlling light sources in the master video display device and the slave video display device and further controls the light source of the master video display device based on the common video setting values, a first data input unit that inputs second video feature data indicating characteristics of the video signals for each of the master video display device and the slave video display device from the preceding slave video display device, and a first data output unit that outputs the first video feature data or the common video setting value to the succeeding slave video display device. The slave video display device includes a second video feature data extraction unit that extracts first video feature data indicating features of the received video signal from the video signal, a second data input unit that inputs the second video feature data indicating features of the video signal for the preceding master video display device or slave video display device or a common video setting value generated by the master video display device, a second controller that calculates third video feature data and controls the light source of the slave video display device based on the common video setting value, and a second data output unit that outputs the third video feature data or the common video setting value to the following master video display device or slave video display device. The master video display device outputs the first video feature data extracted by the first video feature data extraction unit to the following slave video display device, and then, when the second video feature data is input by the first data input unit, calculates the common video setting value based on the input second video feature data and outputs the calculated common video setting value to the following slave video display device.When the slave video display device receives second video feature data from the upstream video display device, it generates third video feature data from the first video feature data extracted by the second video feature data extraction unit and the received second video feature data, outputs the generated third video feature data to the downstream video display device, and then, when it receives a common video setting value from the upstream video display device, outputs the received common video setting value to the downstream video display device. [Effects of the Invention]

[0008] The video display device of the present disclosure is configured to use multiple units to form a multi-display device, and when a single screen of video is constructed from multiple display screens, this eliminates any sense of discomfort felt by the viewer due to differences in the characteristics of each display screen. [Brief explanation of the drawings]

[0009] [Figure 1] 1 shows the configuration of a conventional multi-display device. [Figure 2] 1 is a diagram showing a configuration of a multi-display device according to an embodiment; [Figure 3] 1 is a block diagram of a projector according to a first embodiment; [Figure 4] FIG. 1 is a diagram for explaining the operation of the multi-display device according to the first embodiment. [Figure 5] FIG. 1 is a diagram for explaining the operation of the multi-display device according to the first embodiment. [Figure 6] A diagram showing an example of a lookup table showing the relationship between APL and light intensity coefficient [Figure 7] FIG. 1 is a diagram for explaining the effects of the embodiment. [Figure 8] 1 is a block diagram of a projector according to a second embodiment. [Figure 9] FIG. 10 is a diagram for explaining the operation of the multi-display device according to the second embodiment. [Figure 10] FIG. 10 is a diagram for explaining the operation of the multi-display device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of well-known matters or redundant explanation of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following explanation and to facilitate understanding by those skilled in the art.

[0011] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0012] (Embodiment 1) Hereinafter, an embodiment will be described with reference to FIGS.

[0013] FIG. 1 shows a conventional multi-display device in which three projectors—Projector 1 (PJ1), Projector 2 (PJ3), and Projector 3 (PJ3)—are aligned horizontally across a screen, projecting images from each projector to form a single image. Projector 1, Projector 2, and Projector 3 control the brightness of their light sources according to the average luminance level (APL) of the images input to each projector to address the perceived lack of brightness in bright scenes and the black floating in dark scenes, i.e., to improve dynamic contrast. If the APL of the images projected by Projector 1 and Projector 3 is 0% and the APL of the image projected by Projector 2 is 15%, viewing these images as a single image results in inconsistent brightness. This creates a sense of discomfort for the viewer, degrading the display quality of the image.

[0014] Therefore, in this embodiment, such inconvenience is avoided by the configuration described below.

[0015] Fig. 2 is a diagram showing the configuration of a multi-display device 10 using projectors according to this embodiment. As shown in Fig. 2, multi-display device 10 is configured by interconnecting the control information input unit and control information output unit of projector 100M, projector 100S1, and projector 100S2, and connecting the three projectors in a loop shape with cables (signal lines).

[0016] That is, control information output unit 102M of projector 100M is connected to control information input unit 101S1 of projector 100S1. Control information output unit 102S1 of projector 100S1 is connected to control information input unit 101S2 of projector 100S2. Control information output unit 102S2 of projector 100S2 is connected to control information input unit 101M of projector 100M.

[0017] 2, a first video signal is input to projector 100M from a video signal source, and an image based on this first video signal is projected onto screen 300. A second video signal is input to projector 100S1 from a video signal source, and an image based on this second video signal is projected onto screen 300. A third video signal is input to projector 100S2 from a video signal source, and an image based on this third video signal is projected onto screen 300. The images based on these first to third video signals are lined up on screen 300 to form a single image.

[0018] FIG. 3 is a block diagram showing the configuration of a projector. In this embodiment, projector 100M, projector 100S1, and projector 100S2 have the same configuration. That is, projectors 100M, 100S1, and 100S2 have the same configuration as projector 100 shown in FIG. 3. However, one of projectors 100M, 100S1, and 100S2 has a different function from the other projectors. Specifically, projector 100M functions as a master projector, and projectors 100S1 and 100S2 function as slave projectors (details will be described later).

[0019] 3, projector 100 includes control information input unit 101, control information output unit 102, video signal receiving unit 103, video display element driving unit 104, video display element 105, light source luminance control unit 106, light source driving unit 107, light source 108, pixel number calculation unit 109, controller 110, master / slave setting unit 114, and average luminance detection unit 115. Master / slave setting unit 114 is set by remote control 200 that operates projector 100. Control information input unit 101 is an example of a data input unit, and control information output unit 102 is an example of a data output unit.

[0020] A video signal input to projector 100 is input to video signal receiving unit 103. The video signal input to video signal receiving unit 103 is delayed by a predetermined time to eliminate discrepancies in the display timing due to delays in signal processing by the three projectors, and then input to video display element driving unit 104. Video display element driving unit 104 drives video display element 105 based on the video signal. A DMD (Digital Mirror Device) is used as the video display element.

[0021] Control information from other projectors connected in a loop is input to the control information input unit 101. This control information includes information on the total number of effective pixels, an effective APL coefficient, and an average APL, which will be described later.

[0022] The control information input to the control information input unit 101 is input to the controller 110. The controller 110 is responsible for overall control of the projector 100 and is configured, for example, by an FPGA (Field-Programmable Gate Array). The controller 110 includes an effective APL coefficient calculation / addition unit 111, a pixel number addition unit 112, a light source control amount calculation unit 113, and a lookup table 119. The lookup table 119 is used when determining a light intensity coefficient for enhancing dynamic contrast from APL information.

[0023] A light source luminance control unit 106 is controlled under the control of the controller 110. The light source luminance control unit 106, which is controlled by the controller 110, controls a light source drive unit 107. The light source drive unit 107 drives a light source 108 based on the control of the light source luminance control unit 106. A solid-state light source such as a semiconductor laser diode, a metal halide lamp, or the like can be used as the light source 108. Illumination light from this light source 108 is irradiated onto an image display element 105, and the image display element 105 modulates the irradiated light based on an image signal to generate image light that forms a display screen. This image light is enlarged and projected onto a screen by a projection optical system (not shown).

[0024] The controller 110 is supplied with information on the number of effective pixels of the image display element 105 of the projector 100 from the pixel number calculation unit 109. The controller 110 also receives a setting signal from the master / slave setting unit 114.

[0025] The average brightness detection unit 115 calculates an average brightness level (APL) from the input video signal and supplies it to the controller 110. The average brightness detection unit 115 calculates the average brightness level of the input video signal for each frame. The APL (average brightness level) is an example of first video feature data, and the average brightness detection unit 115 is an example of a video feature data extraction unit.

[0026] Controller 110 receives control information (second image feature data) from a preceding projector connected to this projector from control information input unit 101. Controller 110 also receives APL information (first image feature data) from average luminance detection unit 115, and information on effective pixels of the projector from pixel number calculation unit 109. Controller 110 outputs the result of calculation based on these data (third image feature data) to control information output unit 102. Control information output unit 102 outputs the output data from controller 110 to a succeeding projector connected to this projector. A vertical synchronization signal VS synchronized with the video signal is supplied to controller 110 to time the display of the image. The information on effective pixels is an example of video display device information.

[0027] Next, steps for configuring a system using the projectors shown in FIGS. 2 and 3 and setting up a multi-display device will be described.

[0028] First, the light intensity set for the brightest projected image scene of projector 100M, projector 100S1, and projector 100S2 is adjusted to be the same for all of them. Although the light intensity can be adjusted to decrease for each individual projector, it cannot be adjusted to exceed the maximum light intensity. Therefore, the light intensity of the three projectors is adjusted to match that of the one with the smallest maximum light intensity. This adjustment can be made by issuing a command to the controller using a remote control, and by visually adjusting the screen brightness. In addition to visual adjustment, the projected image can be photographed with a camera, the photographed image processed by a personal computer (PC), and the maximum light intensity of each projector can be adjusted under the control of the PC.

[0029] Next, the projector 100 is connected in a loop shape with a cable as shown in FIG.

[0030] After connecting the projectors 100 in a loop, one of the three projectors is set as the master and the other two as slaves. This setting is performed by turning on the interlocking operation with the remote control 200 in the interlocking operation on / off menu of the OSD (on-screen display) for each projector, and selecting whether to set the master or slave in the master / slave setting unit 114. In this embodiment, the projector 100M is set as the master, and the projectors 100S1 and 100S2 are set as slaves.

[0031] Here, the number of effective pixels of the image display element of projector 100M is 100 pixels vertically and 100 pixels horizontally, that is, 10,000 pixels, the number of effective pixels of the image display element of projector 100S1 is 90 pixels vertically and 100 pixels horizontally, that is, 9,000 pixels, and the number of effective pixels of the image display element of projector 100S2 is 100 pixels vertically and 100 pixels horizontally, that is, 10,000 pixels. The pixel counts of these projectors are set to small numbers to simplify the explanation.

[0032] In this way, when the video display devices are connected in a loop with cables to form the multi-display device 10, a video signal is supplied to each projector.

[0033] Here, we will explain a case where, at a certain timing, a first video signal with an APL of 10% is input to projector 100M, a second video signal with an APL of 20% is input to projector 100S1, and a third video signal with an APL of 60% is input to projector 100S2, as shown in Figure 4.

[0034] Projectors 100M, 100S1, and 100S2 perform two loop processes for each frame of the video signal. In the first loop process, the APLs of the images represented by the first to third video signals input to projectors 100M, 100S1, and 100S2 are added and accumulated to determine the cumulative APL value for the entire image projected by these projectors. Next, in the second loop process, the average APL for the entire image is determined based on the cumulative APL value, and this average APL is shared by projectors 100M, 100S1, and 100S2. Each projector 100M, 100S1, and 100S2 controls the light intensity of its light source based on the common average APL. These loop processes are described in detail below.

[0035] (First loop processing) First, master projector 100M detects the APL level (10%) using average brightness detection unit 115 and inputs this value to controller 110. Controller 110 obtains the number of effective pixels (10,000) of projector 100M from pixel number calculation unit 109, and calculates the effective APL coefficient (1,000) by multiplying the APL level (10%) by the number of effective pixels (10,000) in effective APL coefficient calculation / addition unit 111. The effective APL coefficient calculated in this way, together with the number of effective pixels (total number of effective pixels) of projector 100M, is input from control information output unit 102M to control information input unit 101S1 of slave projector 100S1.

[0036] Slave projector 100S1 detects the APL level (20%) using its average brightness detection unit 115 and inputs this value to controller 110. Controller 110 obtains the number of effective pixels (9000) of projector 100S1 from pixel number calculation unit 109, and calculates the effective APL coefficient (1800) by multiplying the APL level (20%) by the number of effective pixels (9000) in effective APL coefficient calculation / addition unit 111. The effective APL coefficient (1800) calculated in this manner is added to the effective APL coefficient (1000) from projector 100M in effective APL coefficient calculation / addition unit 111, thereby obtaining an accumulated effective APL coefficient (2800).

[0037] Furthermore, pixel number adding unit 112 adds the number of effective pixels (9000) of projector 100S1 and the number of effective pixels (10000) of projector 100M to obtain the accumulated total number of effective pixels (19000). The effective APL coefficient (2800), together with the total number of effective pixels (19000), is input from control information output unit 102S1 of projector 100S1 to control information input unit 101S2 of slave projector 100S2.

[0038] Slave projector 100S2 detects the APL level (60%) using its average brightness detection unit 115 and inputs this value to controller 110. Controller 110 obtains the number of effective pixels (10,000) of projector 100S2 from pixel number calculation unit 109, and calculates the effective APL coefficient (6,000) by multiplying the APL level (60%) by the number of effective pixels (10,000) in effective APL coefficient calculation / addition unit 111. The effective APL coefficient (6,000) calculated in this manner is added to the effective APL coefficient (2,800) from projector 100S1 in effective APL coefficient calculation / addition unit 111, thereby obtaining an accumulated effective APL coefficient (8,800).

[0039] Furthermore, pixel number adding unit 112 adds the number of effective pixels (10,000) of projector 100S2 and the total number of effective pixels (19,000) from projector 100S1 to obtain a cumulative total number of effective pixels (29,000). The effective APL coefficient (8,800) and the total number of effective pixels (29,000) are input from control information output unit 102S2 of projector 100S2 to control information input unit 101M of master projector 100M. In this way, in the first loop processing, the cumulative APL value of the entire image projected by projectors 100M, 100S1, and 100S2 is found.

[0040] (Second loop processing) Next, as shown in FIG. 5, master projector 100M obtains an average APL (30.3%) in light source control amount calculation unit 113 of controller 110 by dividing the effective APL coefficient (8,800) input to control information input unit 101M by the total effective pixel count (29,000). Master projector 100M then references lookup table 119 provided in controller 110. Lookup table 119 stores data showing the relationship between the APL and the light intensity coefficient, as shown in FIG. 6. Master projector 100M uses this lookup table to obtain the light intensity coefficient (51%) set for the average APL (30.3%), and sets the light intensity of the light source by controlling light source luminance control unit 106 based on this light intensity coefficient (51%). The average APL is an example of a common video setting value or common average luminance information.

[0041] Average APL (30.3%) obtained by master projector 100M is input from control information output unit 102M to control information input unit 101S1 of slave projector 100S1. Slave projector 100S1 refers to lookup table 119 provided in controller 110, obtains the light intensity coefficient (51%) to be set for average APL (30.3%), and sets the light intensity of the light source by controlling light source luminance control unit 106 based on this light intensity coefficient (51%).

[0042] Slave projector 100S1 inputs the average APL (30.3%) output from master projector 100M from control information output unit 102S1 to control information input unit 101S2 of slave projector 100S2. Slave projector 100S2 references lookup table 119 provided in controller 110, obtains the light intensity coefficient (51%) set for the average APL (30.3%), and sets the light intensity of the light source by controlling light source luminance control unit 106 based on this light intensity coefficient (51%). Slave projectors 100S1 and 100S2 recognize that the average APL has been input, for example, from the header information of the data generated by master projector 100M and input to control information input units 101S1 and 101S2.

[0043] After this, slave projector 100S2 inputs the average APL (30.3%) output from master projector 100M from control information output unit 102S2 to control information input unit 101M of master projector 100M. When master projector 100M receives the average APL (30.3%) from slave projector 100S2, it recognizes that slave projector 100S1 and slave projector 100S2 have been set to the specified average APL, and ends the setting. Note that this recognition by master projector 100M that it has received the average APL (30.3%) from slave projector 100S2 can be used to confirm that the control information has been transmitted correctly, but is not essential. The above series of operations is performed for each frame of the video signal.

[0044] Here, as described above, if each of projectors 1 to 3 individually controls the brightness of its light source, as in the conventional multi-display device shown in Fig. 1, when the images of projectors 1 to 3 are viewed as a single image, the brightness will be uneven. For example, if the APL and light intensity coefficient have the relationship shown in Fig. 6, and the APL of the image of projector 1 is 10%, the APL of the image of projector 2 is 20%, and the APL of the image of projector 3 is 60%, the light intensity of the light source of projector 1 is controlled with a light intensity coefficient of 20%, the light intensity of the light source of projector 2 is controlled with a light intensity coefficient of 40%, and the light intensity of the light source of projector 3 is controlled with a light intensity coefficient of 90%. In this case, when the images of projectors 1 to 3 are viewed as a single image, the brightness will be uneven, causing a sense of discomfort to the viewer.

[0045] In contrast, in this embodiment, as shown in FIG. 7, the APLs of master projector 100M, slave projector 100S1, and slave projector 100S2 are set to the same value (30.3%) for each frame, and when they are combined into a single image, there is no unevenness in brightness, and the viewer does not feel uncomfortable.

[0046] As described above, in the present embodiment, multi-display device 10 includes master projector 100M and slave projectors 100S1 and 100S2 connected in a loop by coupling each other's data input section and data output section with a signal line.

[0047] Master projector 100M includes light source 108, light source luminance control unit 106, image display element 105, image signal receiving unit 103, average luminance detection unit 115, controller 110, control information input unit 101, and control information output unit 102. Light source luminance control unit 106 controls light source 108. Image display element 105 modulates light from light source 108 based on a video signal to generate image light that forms a display screen. Video signal receiving unit 103 receives the video signal. Average luminance detection unit 115 extracts an APL indicating the average luminance level of the video signal from the video signal received by video signal receiving unit 103. Controller 110 generates an average APL for controlling the light sources in master projector 100M and slave projectors 100S1 and 100S2, and further controls light source 108 of master projector 100M based on the average APL. Control information input unit 101 inputs the accumulated value of the effective APL coefficient indicating the average brightness level of the video signal for its own device and for each of slave projectors 100S1 and 100S2 from previous-stage slave projector 100S2. Control information output unit 102 outputs the APL or average APL to subsequent-stage slave projector 100S1. Controller 110 outputs the APL extracted by average brightness detection unit 115 to subsequent-stage slave projector 100S1, and then, when the accumulated value of the effective APL coefficient is input from previous-stage slave projector 100S2, controller 110 calculates the average APL based on the accumulated value of the input effective APL coefficient, and outputs the calculated average APL to subsequent-stage slave projector 100S1.

[0048] Slave projectors 100S1 and 100S2 each include light source 108, light source luminance control unit 106, image display element 105, image signal receiving unit 103, average luminance detection unit 115, controller 110, control information input unit 101, and control information output unit 102. Light source luminance control unit 106 controls light source 108. Image display element 105 modulates light from light source 108 based on a video signal to generate image light that forms a display screen. Video signal receiving unit 103 receives the video signal. Average luminance detection unit 115 extracts an APL indicating the average luminance level of the video signal from the video signal received by video signal receiving unit 103. Control information input unit 101 inputs an effective APL coefficient indicating the average luminance level of the video signal for the preceding projector, or an average APL for controlling the light sources in the projector itself and slave projectors 100S1 and 100S2. The controller 110 calculates an effective APL coefficient and controls the light source of the device itself based on the average APL. The control information output unit 102 outputs the effective APL coefficient or the average APL to a subsequent projector. When the controller 110 receives an effective APL coefficient from a previous projector, the controller 110 generates a cumulative value of the effective APL coefficient from the APL of the device itself and the effective APL coefficient of the previous projector, outputs the generated cumulative value of the effective APL coefficient to the subsequent projector, and then, when the controller 110 receives an average APL from the previous projector, outputs the input average APL to the subsequent projector.

[0049] As described above, master projector 100M outputs an APL indicating the average brightness level of its own video signal to downstream slave projector 100S1. Master projector 100M then generates an average APL for controlling the light sources in its own device and slave projectors 100S1 and 100S2 based on the cumulative value of effective APL coefficients indicating the average brightness level of the video signals for its own device and slave projectors 100S1 and 100S2 returned from slave projector 100S2, and outputs this average APL to slave projector 100S1. This allows master projector 100M and slave projectors 100S1 and 100S2 to control the light intensity of their light sources to be identical based on the average APL. Therefore, when a single screen of image is constructed from a plurality of display screens displayed by master projector 100M and slave projectors 100S1 and 100S2, there is no unevenness in brightness, and the viewer does not feel uncomfortable.

[0050] As described above, slave projectors 100S1 and 100S2 generate cumulative effective APL coefficients based on the effective APL coefficients from the preceding projector and their own APLs, and output the cumulative effective APL coefficients to the succeeding projectors. This allows the cumulative effective APL coefficients of all video signals from master projector 100M and slave projectors 100S1 and 100S2 to be returned to master projector 100M. Therefore, master projector 100M can generate an average APL for controlling the light sources of master projector 100M and slave projectors 100S1 and 100S2 based on this cumulative effective APL coefficient. Slave projectors 100S1 and 100S2 then control their light sources based on the average APL from master projector 100M. This allows the master projector 100M and the slave projectors 100S1 and 100S2 to control the light intensity of their light sources to be the same based on the average APL, which eliminates uneven brightness when composing a single screen of image from multiple display screens displayed by the master projector 100M and the slave projectors 100S1 and 100S2, and prevents viewers from feeling uncomfortable.

[0051] (Embodiment 2) The second embodiment will be described with reference to FIGS. 8 to 10 and 6. FIG.

[0052] FIG. 8 is a block diagram showing the configuration of projector 100a according to the second embodiment. Projector 100a according to the second embodiment differs from projector 100 according to the first embodiment shown in FIG. 3 in the internal configuration of controller 116. That is, controller 116 includes average brightness adder 117, number-of-unit information adder 118, and light source control amount calculator 113. Projector 100a does not include pixel number calculator 109. Note that in projector 100a in FIG. 8, components that are the same as those in projector 100 according to the first embodiment shown in FIG. 3 are designated by the same reference numerals, and redundant description will be omitted.

[0053] 9 is a diagram showing a multi-display device 10 using projector 100a according to the present embodiment. In the multi-display device 10, similar to the first embodiment, the control information input unit and control information output unit of each of projector 100aM, projector 100aS1, and projector 100aS2 are connected to each other, and the three projectors are connected in a loop shape with cables.

[0054] That is, the control information output unit 102aM of the projector 100aM is connected to the control information input unit 101aS1 of the projector 100S1. The control information output unit 102aS1 of the projector 100S1 is connected to the control information input unit 101aS2 of the projector 100S2. The control information output unit 102aS2 of the projector 100S2 is connected to the control information input unit 101aM of the projector 100M.

[0055] 9, a first video signal is input to projector 100aM from a video signal source, and an image based on this first video signal is projected onto screen 300. A second video signal is input to projector 100aS1 from the video signal source, and an image based on this second video signal is projected onto screen 300. A third video signal is input to projector 100aS2 from the video signal source, and an image based on this third video signal is projected onto screen 300. The images based on these first to third video signals are lined up on screen 300 to form a single image.

[0056] Returning to Fig. 8, control information from the projectors connected in a loop is input to the control information input unit 101. This control information includes APL information, information on the number of connected projectors, and average APL information.

[0057] The control information input to the control information input unit 101 is input to the controller 116. The controller 116 is responsible for overall control of the projector 100a, and in this embodiment is also configured by an FPGA. The controller 116 includes the average brightness addition unit 117, the number of projector information addition unit 118, and the light source control amount calculation unit 113, as described above.

[0058] Next, steps for setting up a multi-display device using the projector shown in FIG. 8 will be described.

[0059] First, the light intensities set for the brightest projected image scenes of the projectors 100aM, 100aS1, and 100aS2 are adjusted so that they are the same. The details of this setting are the same as in the first embodiment, so a description thereof will be omitted.

[0060] Next, the projector 100a is connected with a cable in a loop shape as shown in FIG.

[0061] After connecting the projectors 100a in a loop, one of the three projectors is set as the master and the other two as slaves. The details of this setting are the same as in the first embodiment, so a description thereof will be omitted.

[0062] In this way, when the video display devices are connected in a loop with cables to form the multi-display device 10, a video signal is supplied to each projector.

[0063] Here, we will explain a case where, at a certain timing, a first video signal with an APL of 10% is input to projector 100aM, a second video signal with an APL of 20% is input to projector 100aS1, and a third video signal with an APL of 60% is input to projector 100aS2, as shown in Figure 9.

[0064] (First loop processing) First, master projector 100aM detects APL level (10%) with average brightness detection unit 115 and inputs this value to controller 116. Controller 116 outputs APL (10%), which is an accumulated value obtained by adding APL level (10%) to "0" with average brightness addition unit 117, from control information output unit 102aM and inputs this to control information input unit 101aS1 of projector 100aS1. Controller 116 of master projector 100aM outputs "1", which is an accumulated value obtained by adding "1", the number of projectors itself, to "0" with unit number information addition unit 118, from control information output unit 102aM and inputs this to control information input unit 101aS1 of slave projector 100aS1.

[0065] Slave projector 100aS1 detects the APL level (20%) with its average brightness detection unit 115 and inputs this value to controller 116. Controller 116 causes average brightness addition unit 117 to output APL (30%), which is an accumulated value obtained by adding the APL level (20%) to the APL value (10%) input to control information input unit 101aS1, from control information output unit 102aS1, and inputs this to control information input unit 101aS2 of slave projector 100aS2. Controller 116 of slave projector 100aS1 outputs from control information output unit 102aS1, by means of unit number information addition unit 118, the cumulative value "2" obtained by adding the number "1" that counts its own number to the unit number information "1" input to control information input unit 101aS1, and inputs this to control information input unit 101aS2 of slave projector 100aS2.

[0066] Slave projector 100aS2 detects the APL level (60%) using average brightness detection unit 115 and inputs this value to controller 116. Controller 116 outputs APL (90%), which is an accumulated value obtained by adding the APL value (30%) input to control information input unit 101aS2 to the APL level (60%) using average brightness addition unit 117, from control information output unit 102aS2, and inputs this to control information input unit 101aM of master projector 100aM. Controller 116 of slave projector 100aS2 outputs from control information output unit 102aS2, using unit number information addition unit 118, an accumulated value of "3" obtained by adding the unit number information "2" input to control information input unit 101aS2 to the number of units "1" that counts its own number, to "3", and inputs this to control information input unit 101aM of master projector 100aM.

[0067] (Second loop processing) Next, master projector 100aM obtains average APL (30%) by dividing the cumulative value (90%) of APL input to control information input unit 101aM by the number of units information (total number 3) in light source control amount calculation unit 113 of controller 116, as shown in Fig. 10. After this, master projector 100aM refers to lookup table 119 provided in controller 116. Lookup table 119 stores data showing the relationship between APL and light intensity coefficient as shown in Fig. 6, and this lookup table is used to obtain light intensity coefficient (50%) to be set for average APL (30%), and light source luminance control unit 106 is controlled based on this light intensity coefficient (50%).

[0068] Average APL (30%) obtained by master projector 100M is input from control information output unit 102aM to control information input unit 101aS1 of slave projector 100aS1. Slave projector 100aS1 refers to lookup table 119 provided in controller 116, obtains light intensity coefficient (50%) set for average APL (30%), and controls light source luminance control unit 106 based on this light intensity coefficient (50%).

[0069] Slave projector 100aS1 inputs average APL (30%) output from master projector 100M from control information output unit 102aS1 to control information input unit 101aS2 of slave projector 100aS2. Slave projector 100aS2 references lookup table 119 provided in controller 116, obtains light intensity coefficient (50%) set for average APL (30%), and controls light source luminance control unit 106 based on this light intensity coefficient (50%).

[0070] After this, slave projector 100aS2 inputs the average APL (30%) output from master projector 100aM from control information output unit 102aS2 to control information input unit 101aM of master projector 100aM. When master projector 100aM receives the average APL (30%) from slave projector 100aS2, it recognizes that slave projector 100aS1 and slave projector 100aS2 have been set to the specified average APL, and completes the setting. This recognition by master projector 100aM that it has received the average APL (30%) from slave projector 100aS2 can be used to confirm that the control information has been transmitted correctly, but is not essential. The above series of operations is performed for each frame of the video signal.

[0071] This embodiment also provides the same advantages as the first embodiment. Master projector 100aM outputs an APL indicating the average brightness level of its own video signal to downstream slave projector 100aS1. Then, master projector 100aM generates an average APL for controlling the light sources of its own device and slave projectors 100aS1 and 100aS2 based on the cumulative values ​​of APLs indicating the average brightness levels of the video signals for its own device and slave projectors 100aS1 and 100S2 returned from slave projector 100aS2, and outputs this average APL to slave projector 100aS1. This allows master projector 100aM and slave projectors 100aS1 and 100aS2 to control the light intensity of their light sources to be the same based on the average APL. Therefore, when composing a single screen of image from multiple display screens displayed by master projector 100aM and slave projectors 100aS1 and 100aS2, there is no unevenness in brightness, and the viewer does not feel uncomfortable.

[0072] In addition, slave projectors 100aS1 and 100aS2 generate an accumulated APL value based on the APL from the preceding projector and their own APL, and output it to the succeeding projectors. This allows the accumulated APL values ​​of all video signals from master projector 100aM and slave projectors 100aS1 and 100aS2 to be returned to master projector 100aM. Therefore, master projector 100aM can generate an average APL for controlling the light sources of master projector 100aM and slave projectors 100aS1 and 100aS2 based on this accumulated APL value. Slave projectors 100aS1 and 100aS2 then control their light sources based on the average APL from master projector 100aM. This allows the master projector 100aM and the slave projectors 100aS1 and 100aS2 to control the light intensity of their light sources to be the same based on the average APL. As a result, when composing a single screen's worth of image from multiple display screens displayed by the master projector 100aM and the slave projectors 100aS1 and 100aS2, there is no unevenness in brightness, and the viewer does not feel uncomfortable.

[0073] (Other embodiments) As described above, the embodiments have been described as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in the above embodiments to create new embodiments.

[0074] (1) That is, in the present disclosure, three projectors are connected as an example, but the present disclosure can be applied to a case where two or more projectors are connected in a loop.

[0075] (2) The controller is configured using an FPGA, but it can also be configured using a microcomputer.

[0076] (3) A projector is used as the image display device, but this is just an example and the image display device is not limited to this. A liquid crystal display device or an LED (Light Emitting Diode) display device may also be used.

[0077] (4) In addition, in this embodiment, the average APL (average brightness level) of the entire image projected by the three projectors is calculated, and the light intensity of the light source is controlled based on this average APL. However, the present disclosure is not limited to this. In addition to the average APL of the entire image projected by the multiple projectors, the peak brightness of the entire image may be calculated, and the light intensity of the light source may be controlled based on this average APL and peak brightness. Below, an example of applying this idea to embodiment 1 will be described, but this idea can also be applied to embodiment 2 in the same way.

[0078] For example, in the first embodiment, average brightness detection unit 115 detects the peak brightness (first image feature data) of the image represented by the input image signal. Controller 110 compares the peak brightness from average brightness detection unit 115 with the peak brightness (second image feature data) from the preceding projector input to control information input unit 101, selects the larger one, and outputs the selected peak brightness (third image feature data) to the subsequent projector via control information output unit 102. That is, the first image feature data includes the peak brightness in addition to the above-mentioned APL, and the second and third image feature data include peak brightness in addition to the above-mentioned average APL.

[0079] More specifically, in the first loop processing, master projector 100M detects the peak luminance of the image represented by the video signal input to it using average luminance detection unit 115. Controller 110 of master projector 100M outputs the peak luminance detected by average luminance detection unit 115 to slave projector 100S1 via control information output unit 102M. Slave projector 100S1 detects the peak luminance of the image represented by the video signal input to it using average luminance detection unit 115. Controller 110 of slave projector 100S1 compares the peak luminance detected by average luminance detection unit 115 with the peak luminance input from projector 100M via control information input unit 101S1, and outputs the larger peak luminance to slave projector 100S2 via control information output unit 102S1. Slave projector 100S2 detects the peak luminance of the image indicated by the video signal input to it using average luminance detection unit 115. Controller 110 of slave projector 100S2 compares the peak luminance detected by average luminance detection unit 115 with the peak luminance input from projector 100S1 via control information input unit 101S2, and outputs the greater peak luminance to master projector 100M via control information output unit 102S2. This allows master projector 100M to know the peak luminance of the entire image.

[0080] Next, in the second loop process, the master projector 100M takes peak luminance into consideration when setting the light source intensity based on the average APL of the entire image as described above. For example, if the peak luminance is higher than a predetermined value, the master projector 100M will not set an average APL lower than a predetermined value. This makes it possible to avoid over-reducing the light source intensity in an image with a low APL, such as an image of a night sky, which would result in the stars in the image becoming dim.

[0081] (5) In addition, in the present disclosure, instead of the average APL (average brightness level) of the entire image projected by multiple projectors, a histogram of the brightness of the entire image (for example, a brightness distribution) may be calculated, and the light amount of the light source may be controlled based on this histogram. An example of applying this concept to the first embodiment will be described below, but this concept can also be applied to the second embodiment.

[0082] For example, in the first embodiment, detection unit 115 detects the luminance distribution (first image feature data) of the image represented by the input video signal. For example, the luminance distribution includes the ratio of each of four regions, where the luminance is from 0% to less than 25%, from 25% to less than 50%, from 50% to less than 75%, and from 75% to less than 100%, to the entire image. Controller 110 adds the luminance distribution from detection unit 115 and the luminance distribution (second image feature data) from the preceding projector input to control information input unit 101 for each of the four luminance regions, and outputs the accumulated average luminance distribution (third image feature data) to the subsequent projector via control information output unit 102. That is, the first image feature data includes the luminance distribution instead of the above-mentioned APL, and the second and third image feature data include the average luminance distribution instead of the above-mentioned average APL.

[0083] More specifically, in the first loop processing, master projector 100M detects the luminance distribution of the image represented by the video signal input to it using detection unit 115. Controller 110 of master projector 100M outputs the luminance distribution detected by detection unit 115 to slave projector 100S1 via control information output unit 102M. Slave projector 100S1 detects the luminance distribution of the image represented by the video signal input to it using detection unit 115. Controller 110 of slave projector 100S1 adds the luminance distribution detected by detection unit 115 and the luminance distribution input from projector 100M via control information input unit 101S1 for each of the four luminance regions, and outputs the accumulated average luminance distribution to slave projector 100S2 via control information output unit 102S1. Slave projector 100S2 detects the luminance distribution of the image indicated by the video signal input to it using detection unit 115. Controller 110 of slave projector 100S2 adds the luminance distribution detected by detection unit 115 and the luminance distribution input from projector 100S1 via control information input unit 101S2 for each of the four luminance regions, and outputs the accumulated average luminance distribution to master projector 100M via control information output unit 102S2. This allows master projector 100M to know the average luminance distribution of the entire image.

[0084] Next, in the second loop process, master projector 100M sets a common setting value for the light intensity of the light source based on the average luminance distribution of the entire image. Master projector 100M and slave projectors 100S1 and 100S2 then set the light intensity of their own light sources based on this common setting value.

[0085] It should be noted that the above-described embodiments are intended to illustrate the technology of the present disclosure, and various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents. [Industrial Applicability]

[0086] The present disclosure is applicable to image display devices such as projectors. [Explanation of symbols]

[0087] 10 Multi-display device 1, 2, 3, 100, 100a projector 100M, 100aM projector 100S1, 100aS1 projectors 100S2, 100aS2 projector 101 Control information input unit 101M, 101S1, 101S2 Control information input section 101aM, 101aS1, 101aS2 Control information input section 102M, 102S1, 102S2 Control information output section 102aM, 102aS1, 102aS2 Control information output section 102 Control information output unit 103 Video signal receiving unit 104 Image display element driver 105 Image display element 106 Light source brightness control section 107 Light source driver 108 Light source 109 Pixel Count Calculation Unit 110 Controller 111 Effective APL coefficient calculation / addition section 112 Pixel number addition unit 113 Light source control amount calculation unit 114 Master / Slave Setting Section 115 Average brightness detection unit 116 Controller 117 Average luminance addition unit 118 Number of units information addition unit 119 Reference Table 200 Remote Control

Claims

1. A video display device used in a multi-display type video display system that displays videos respectively displayed by a plurality of video display devices as a single video, any other display device of the plurality of image display devices is connected as a subsequent image display device, one of the plurality of image display devices is designated as a master; In the video display system, a master video display system receives a first frame of a video including a plurality of frames, and thereby repeats a first loop and a second loop for each frame of the video; The image display device includes: A light source and a light source control unit that controls the light source; a display element that modulates the light from the light source based on a video signal to generate video light that forms a display screen; a video signal receiving unit that receives the video signal; a controller that receives a luminance level of the video signal and controls the light source in accordance with luminance-related information calculated based on the luminance level; a data output unit that outputs data input from the controller to a downstream video display device, The controller a first loop for transmitting information to a subsequent video display device in sequence among the plurality of video display devices, and a second loop for transmitting a signal to a subsequent video display device in sequence among the plurality of video display devices following the first loop, and repeating the first loop and the second loop; In the first loop and the second loop, a master video display device transmits information or a signal to start the loop, and any video display device transmits information or a signal to the master video display device to end the loop. When the second loop for one frame ends, the first loop for the next frame starts, thereby repeating the steps of moving to the next loop; In the first loop, when information relating to other luminance is not input from the video display device connected to the previous stage, information relating to luminance calculated by the device itself is output to the data output unit, and when information relating to other luminance is input from the video display device connected to the previous stage, a cumulative value obtained by adding the information relating to the luminance calculated by the device itself and the information relating to other luminance is output to the data output unit as new information relating to luminance, In the second loop, a common video setting value to be used for controlling the light source is determined based on a cumulative value of information related to luminance calculated by all of the video display devices, the cumulative value being calculated by sequentially adding up the values ​​received from the video display devices at the previous stage in the first loop. Video display device.

2. the information relating to the luminance is an effective APL coefficient obtained by multiplying the luminance level of the video signal to be displayed on the video display device by the number of effective pixels of the video display device, The common video setting value is a value obtained by dividing the cumulative total of the effective APL coefficients of each video display device by the cumulative total of the number of effective pixels of the display elements of each video display device.

2. The image display device according to claim 1.

3. The information related to the luminance is a luminance level of a video signal to be displayed on the video display device, The common video setting value is a value obtained by dividing the cumulative value of the luminance level of the video signal displayed on each video display device by the total number of video display devices.

2. The image display device according to claim 1.

4. A multi-display type video display system that displays videos displayed by a plurality of video display devices as a single video, any other display device of the plurality of image display devices is connected as a subsequent image display device, one of the plurality of image display devices is designated as a master; a master video display system receives a first frame of a video including a plurality of frames, thereby repeating the first loop and the second loop for each frame of the video; Each of the image display devices includes: A light source and a light source control unit that controls the light source; a display element that modulates the light from the light source based on a video signal to generate video light that forms a display screen; a video signal receiving unit that receives the video signal; a controller that receives a luminance level of the video signal and controls the light source in accordance with luminance-related information calculated based on the luminance level; a data output unit that outputs data input from the controller to a downstream video display device, The controller a first loop for transmitting information to a subsequent video display device in sequence among the plurality of video display devices, and a second loop for transmitting a signal to a subsequent video display device in sequence among the plurality of video display devices following the first loop, and repeating the first loop and the second loop; In the first loop and the second loop, a master video display device transmits information or a signal to start the loop, and any video display device transmits information or a signal to the master video display device to end the loop. When the second loop for one frame ends, the first loop for the next frame starts, thereby repeating the steps of moving to the next loop; In the first loop, when information relating to other luminance is not input from the video display device connected to the previous stage, information relating to luminance calculated by the device itself is output to the data output unit, and when information relating to other luminance is input from the video display device connected to the previous stage, a cumulative value obtained by adding the information relating to the luminance calculated by the device itself and the information relating to other luminance is output to the data output unit as new information relating to luminance, In the second loop, a common video setting value used to control the light source is determined based on an accumulated value of information related to luminance calculated by all of the video display devices, the accumulated value being calculated by sequentially adding up the values ​​received from the video display devices at the previous stage in the first loop. Video display system.

5. the information relating to the luminance is an effective APL coefficient obtained by multiplying the luminance level of the video signal to be displayed on the video display device by the number of effective pixels of the video display device, The common video setting value is a value obtained by dividing the cumulative total of the effective APL coefficients of each video display device by the cumulative total of the number of effective pixels of the display elements of each video display device.

5. The video display system according to claim 4.

6. The information related to the luminance is a luminance level of a video signal to be displayed on the video display device, The common video setting value is a value obtained by dividing the cumulative value of the luminance level of the video signal displayed on each video display device by the total number of video display devices.

5. The video display system according to claim 4.

7. A brightness adjustment method for a video display device used in a multi-display type video display system in which videos respectively displayed by a plurality of video display devices are displayed as a single video, comprising: any other display device of the plurality of image display devices is connected as a subsequent image display device, one of the plurality of image display devices is designated as a master; In the video display system, a master video display system receives a first frame of a video including a plurality of frames, and thereby repeats a first loop and a second loop for each frame of the video; a controller of the image display device inputs a luminance level of a video signal, and controls a light source of the image display device in accordance with information related to luminance calculated based on the luminance level; An adjustment method in which data input from the controller is output to a downstream video display device by a data output unit of the video display device, The controller a first loop for transmitting information to a subsequent video display device in sequence among the plurality of video display devices, and a second loop for transmitting a signal to a subsequent video display device in sequence among the plurality of video display devices following the first loop, and repeating the first loop and the second loop; In the first loop and the second loop, a master video display device transmits information or a signal to start the loop, and any video display device transmits information or a signal to the master video display device to end the loop. When the second loop for one frame ends, the first loop for the next frame starts, thereby repeating the steps of moving to the next loop; In the first loop, when information relating to other luminance is not input from the video display device connected to the previous stage, information relating to luminance calculated by the device itself is output to the data output unit, and when information relating to other luminance is input from the video display device connected to the previous stage, a cumulative value obtained by adding the information relating to the luminance calculated by the device itself and the information relating to other luminance is output to the data output unit as new information relating to luminance, In the second loop, a common video setting value used to control the light source is determined based on an accumulated value of information related to luminance calculated by all of the video display devices, the accumulated value being calculated by sequentially adding up the values ​​received from the video display devices at the previous stage in the first loop. How to adjust brightness.

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