JP2015125243A - Multi-display system, image display device, screen control method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-display system capable of easily correcting unevenness as a whole multi-display screen.SOLUTION: A multi-display system 10 includes: a plurality of image display devices 1 and a computer 4 for control, and each image display device 1 includes: a correction data holding part 122 for holding correction data for an own screen for correcting luminance unevenness in the screen of an own device; a reference data holding part 17 for holding target luminance data for an own screen showing target luminance after correction based on the correction data for an own screen; and a correction arithmetic part 123 for generating an image signal for display by correcting an image signal input from the outside by using the correction data for an own screen. The computer 4 for control acquires the correction data for an own screen and the target luminance data for an own screen from each image display device 1, and calculates the correction data for a multi-screen for correcting the luminance unevenness in the multi-display screen, and the correction arithmetic part 123 generates an image signal for display by using the correction data for a multi-screen.

Description

  The present invention relates to a multi-display system, an image display device, and a screen control method.

  Image display devices represented by liquid crystal display devices, plasma displays, organic EL (Electro-Luminescence) displays, etc., display the brightness and brightness displayed by the pixel position on the screen, even though the same image signal is input. It is known that there are luminance unevenness and color unevenness with different chromaticities. These irregularities are caused by overlapping factors such as variations in film thickness when forming elements on the glass surface of the image display unit during manufacturing and differences in the light amount distribution of the backlight. Different and complicated pattern unevenness occurs.

  For example, Patent Document 1 discloses a method of measuring luminance / chromaticity distribution of a screen when a reference signal is input and correcting different degrees for each pixel according to the measurement result to reduce luminance / color unevenness. .

  On the other hand, in a multi-display system that displays a large screen by arranging a plurality of image display devices adjacent to each other, a luminance difference / color difference between adjacent screens appears as unevenness in the multi-display screen. Methods for adjusting such unevenness between image display devices are disclosed in, for example, Patent Documents 2 and 3.

  In Patent Document 2, an illuminance sensor is provided in each image display device, a reference illuminance is obtained based on data collected from the illuminance sensor of each image display device, and the illuminance of the illuminance sensor associated with each image display device is set to the reference illuminance. A method of adjusting each image display device so as to be close to each other is disclosed. Further, Patent Document 3 discloses a method for efficiently reducing unevenness between image display devices by determining the calibration execution order from the positional relationship between the image display devices.

Japanese Patent No. 4789874 JP 2009-216809 A JP2013-3214A

  However, the method disclosed in Patent Document 1 is a method of performing unevenness correction in a single image display device, and normally, unevenness correction is performed so that the maximum performance can be exhibited for each individual image display device. If the multi-display system is configured by arranging the image display devices that have been subjected to unevenness correction to perform the process, individual differences between the image display devices appear as display unevenness as the entire multi-display screen. In addition, in order to implement high-precision unevenness correction on a pixel basis, high-precision measurement using a surface luminance meter or surface chromaticity meter is necessary. This can only be done at a factory or a special facility corresponding to it, and when configuring a multi-display system in the market, it is not possible to redo high-precision unevenness correction on a pixel-by-pixel basis. On the other hand, when performing unevenness correction at the factory, it is not impossible to set the target brightness of all image display devices to a constant value in advance, but in this case, the capability value of all individuals including those to be produced in the future It is necessary to set the target value below the lower limit, and the performance of all products will be lowered more than necessary.

  On the other hand, Patent Documents 2 and 3 disclose methods for reducing differences between individual image processing apparatuses that constitute a multi-display system. It is necessary to perform measurement with a sensor, and extra equipment and work are required. In general, a multi-display system is intended to form a large screen, and it is assumed that measurement work at a high place is performed on the large screen, which leads to an increase in work risk and man-hours. In addition, measurement in the market can only measure a minimum number of representative points, so high-precision unevenness correction cannot be performed again on a pixel-by-pixel basis, and brightness and chromaticity gains can be displayed on an individual image display unit basis. Although it can only be adjusted uniformly as a whole, it is possible to reduce the difference between the image processing devices to some extent, but it is not possible to realize the optimum unevenness correction processing by regarding the multi-play screen as one screen. .

  An object of the present invention is to make the difference between adjacent image display devices inconspicuous in addition to in-plane unevenness correction of each image display device in a multi-display system constructed by arranging a plurality of image display devices. To provide a multi-display system, an image display device, and a screen control method capable of easily performing unevenness correction for the entire multi-display screen.

The present invention is a multi-display system that constitutes a multi-display screen by arranging a plurality of image display devices capable of displaying an image,
An arithmetic processing unit that calculates correction data for multi-screen for correcting variations in luminance in the multi-display screen.
Each image display device
A correction data storage unit in which correction data for own screen for correcting variations in luminance in the screen of the own device is stored in advance;
A target luminance data storage unit in which self-screen target luminance data indicating the target luminance after correction by the self-screen correction data is stored;
A correction calculation unit that corrects an image signal input from the outside using the correction data for the self-screen, and generates a display image signal;
An image display unit for displaying an image based on the display image signal generated by the correction calculation unit;
A communication processing unit that transmits and receives data to and from the arithmetic processing unit,
The arithmetic processing unit obtains self-screen correction data and self-screen target brightness data from each image display device, and calculates a target brightness for a multi-display screen based on the self-screen target brightness data of each image display device. In addition to calculating, for each image display device, multi-screen correction data is calculated using the corresponding self-screen correction data so that the calculated target luminance is obtained, and the multi-screen correction data is converted into the corresponding image. To the display device,
When the communication processing unit of the image display device receives the multi-screen correction data from the arithmetic processing unit, the correction calculation unit of each image display device converts the image signal input from the outside into the correction data for the multi-screen. The multi-display system is characterized in that a display image signal is generated using the correction.

According to the present invention, the arithmetic processing unit transmits, to the image display devices, multi-screen target luminance data indicating target luminance for the multi-display screen together with the multi-screen correction data.
Each image display device includes a control unit, and when the communication processing unit of the device receives the multi-screen correction data and the multi-screen target luminance data from the arithmetic processing unit, the control unit Correction data is stored in the correction data storage unit of the own device, and the multi-screen target luminance data is stored in the target luminance data storage unit of the own device.

  Further, the present invention is characterized in that the arithmetic processing unit is built in one of the plurality of image display devices.

  Further, according to the present invention, the arithmetic processing unit is configured so that the target brightness increases along a predetermined direction on the multi-display screen based on the self-screen target brightness data acquired from each image display apparatus. It is characterized in that the arrangement order when arranging the images side by side is determined.

Further, the present invention corrects luminance variations in a screen in a multi-display screen configured by a plurality of image display devices arranged side by side and the screens of the plurality of image display devices arranged side by side. An image display device used in a multi-display system including an arithmetic processing unit that calculates correction data for multi-screens,
A correction data storage unit in which correction data for own screen for correcting variations in luminance in the screen of the own device is stored in advance;
A target luminance data storage unit in which self-screen target luminance data indicating the target luminance after correction by the self-screen correction data is stored;
A correction calculation unit that corrects an image signal input from the outside using the correction data for the self-screen, and generates a display image signal;
An image display unit for displaying an image based on the display image signal generated by the correction calculation unit;
A communication processing unit that transmits and receives data to and from the arithmetic processing unit,
When the communication processing unit receives the multi-screen correction data from the arithmetic processing unit, the correction calculation unit corrects an image signal input from the outside using the multi-screen correction data, and displays the correction data. An image display device that generates an image signal.

Further, the present invention corrects luminance variations in a screen in a multi-display screen configured by a plurality of image display devices arranged side by side and the screens of the plurality of image display devices arranged side by side. A correction data storage unit in which each image display device stores in advance correction data for its own screen for correcting variations in luminance within the screen of its own device. And a screen control method in a multi-display system having a target luminance data storage unit in which target luminance data indicating the target luminance after correction by the correction data for the own screen is stored in advance,
The arithmetic processing unit obtains correction data for own screen and target luminance data for own screen from each image display device; and
The arithmetic processing unit calculates a target luminance for a multi-display screen based on the target screen target luminance data of each image display device; and
A correction data calculating step in which the arithmetic processing unit calculates correction data for multi-screen using corresponding correction data for own screen so that the calculated target luminance is obtained for each image display device;
A data transmission step in which the arithmetic processing unit transmits the calculated multi-screen correction data to a corresponding image display device;
When each image display device receives the multi-screen correction data from the arithmetic processing unit, the image display device generates a display image signal by correcting an externally input image signal using the multi-screen correction data. A screen control method comprising: a correction step.

  Further, the present invention is a program for causing a computer to execute the data acquisition step, the target luminance calculation step, the correction data calculation step, and the data transmission step.

  According to the present invention, in a multi-display system in which a plurality of image display devices are arranged and used as a single display device, in addition to in-plane unevenness correction of each image display device, a difference between a plurality of adjacent image display devices And the unevenness appearing on the entire multi-display screen can be easily corrected.

1 is a front view illustrating an example of a configuration of a multi-display system 10 according to a first embodiment of the present invention. 1 is a block diagram schematically showing a configuration example of a multi-display system 10. FIG. 1 is a block diagram illustrating an example of a configuration of an image display device 1 that constitutes a multi-display system 10. FIG. 3 is a conceptual diagram of single unevenness correction processing executed in each of the image display devices 1-1 to 1-n constituting the multi display system 10. FIG. It is a figure for demonstrating the correction data used for a single nonuniformity correction process. When the above-described single unevenness correction processing is executed in each image display device 1 constituting the multi-display system 10, the luminance distribution J1 in the entire multi-display screen when the reference signal is input to each image display device 1 It is a figure which shows an example. FIG. 7 is a diagram illustrating a luminance distribution J2 when the multi-screen unevenness correction process is performed so that the output luminance is uniform over the entire multi-display screen in the multi-display system 10 illustrated in FIG. 6. FIG. 3 is a diagram for explaining multi-screen unevenness correction processing performed in each image display device 1 constituting the multi-display system 10. FIG. 3 is a diagram for explaining multi-screen unevenness correction processing performed in each image display device 1 constituting the multi-display system 10. It is a flowchart which shows the process sequence of the multiscreen nonuniformity correction process which concerns on 1st Embodiment. 3 is a conceptual diagram of single unevenness correction processing executed in each of the image display devices 1-1 to 1-n constituting the multi display system 10. FIG. It is a figure for demonstrating the correction data used for a single nonuniformity correction process. When the above-described single unevenness correction processing is executed in each image display device 1 constituting the multi-display system 10, the luminance distribution J3 in the entire multi-display screen when the reference signal is input to each image display device 1 It is a figure which shows an example. The figure which shows an example of the luminance distribution V in the whole multi display screen when the image display apparatus 1 is arrange | positioned according to a predetermined rule on the basis of arrange | positioning the image display apparatus 1 with the highest minimum output brightness in the center part of a multi display screen. It is. It is a figure which shows the specific arrangement | sequence order when rearranging on the basis of arrange | positioning the image display apparatus 1 with the highest minimum output brightness | luminance in a center part. It is a figure for demonstrating an example of the luminance distribution U by the luminance gradient which becomes ideal in the multi-display system 10 constructed | assembled by arranging the 25 image display apparatuses 1 in the horizontal direction X and the vertical direction Y 5 each. It is a figure which shows the luminance distribution V when the minimum output brightness | luminance is uniformly distributed on each screen in each image display apparatus 1 which comprises the multi-display system 10. FIG. FIG. 17 is a diagram showing a luminance distribution W of target luminance set by multi-screen unevenness correction processing set based on the ideal luminance distribution U shown in FIG. 15 and the luminance distribution V of minimum output luminance shown in FIG. 16.

(First embodiment)
FIG. 1 is a front view showing an example of the configuration of a multi-display system 10 according to the first embodiment of the present invention. In the multi-display system 10, a plurality of image display devices 1 are arranged in a matrix in a plane along the horizontal direction X and the vertical direction Y orthogonal to each other so that the respective screens are arranged adjacent to each other. As shown in FIG. 1, one large screen (hereinafter referred to as “multi-display screen”) is configured by the screen of each image display device 1. The horizontal direction X and the vertical direction Y are directions that coincide with, for example, the horizontal direction and the vertical direction, respectively.

  The arrangement configuration of the image display devices 1 in the multi-display system 10 is not particularly limited. In the following, 25 image display devices 1 are arranged side by side in the horizontal direction X and the vertical direction Y, as shown in FIG. The multi-display system 10 to be constructed will be described as an example.

  FIG. 2 is a block diagram schematically illustrating a configuration example of the multi-display system 10. As shown in FIG. 2, the multi-display system 10 according to the present embodiment includes n image display devices 1-1 to 1-n (hereinafter referred to as “image display device 1” unless it is particularly necessary to distinguish them). And an image signal generation device 2 that inputs an image interface signal to each image display device 1 and a control computer 4 that is communicably connected to each image display device 1 via a communication network 3. Composed. Here, n is an integer of 2 or more, and as described above, n = 25 in the example in the following description.

  The control computer 4 is an arithmetic processing unit having a function of calculating various data used to correct luminance variations (luminance unevenness) appearing on the entire multi-display screen, and includes a CPU (Central Processing Unit), ROM (Read Only Memory) and RAM (Random Access Memory). Hereinafter, processing for correcting luminance unevenness appearing on the entire multi-display screen is referred to as “multi-screen unevenness correction processing” in order to distinguish it from single-unit unevenness correction processing described later.

  In order to execute the multi-screen unevenness correction process, the control computer 4 uses the image display devices 1-1 to 1-n included in the multi-display system 10 in the image display devices 1-1 to 1-n. Correction data and reference data, which will be described later, are stored in advance, and data for multi-screen unevenness correction processing is calculated for each of the image display devices 1-1 to 1-n based on the acquired data. It operates to transmit the calculated data to the corresponding image display devices 1-1 to 1-n.

  As shown in FIG. 2, the control computer 4 may be provided as a device independent of the image display device 1, or one of a plurality of image display devices 1 constituting the multi-display system 10. It may be built in the image display device 1 of the stand.

  FIG. 3 is a block diagram illustrating an example of the configuration of the image display device 1 that configures the multi-display system 10. Note that the image display devices 1-1 to 1-n constituting the multi-display system 10 are configured identically to each other.

  As shown in FIG. 3, the image display device 1 includes an input image processing unit 11, an unevenness correction processing unit 12, an image display unit 14, a communication processing unit 15, a control processing unit 16, and a reference data holding unit 17. These units are connected by an internal data bus 18.

  The input image processing unit 11 receives the image interface signal from the image signal generation device 2 and converts the image interface signal into an image signal for internal processing, and then performs enlargement / reduction processing, color conversion, and other predetermined image processing, and the input image signal To the unevenness correction processing unit 12.

  The unevenness correction processing unit 12 includes a pixel position determination unit 121, a correction data holding unit 122, and a correction calculation unit 123. The pixel position determination unit 121 extracts pixel position information in the screen of the input image signal input from the input image processing unit 11.

  The correction data holding unit 122 holds correction data including common correction data indicating a correction element common to all pixels and a pixel correction coefficient indicating a correction element depending on the pixel position. Correction data corresponding to the extracted pixel position information is output to the correction calculation unit 123. The common correction data and the pixel correction coefficient will be described later.

  The correction calculation unit 123 performs correction calculation processing for each pixel on the input image signal input from the input image processing unit 11 using the correction data provided from the correction data holding unit 122, and obtains a display image signal. Output to the image display unit 14.

  The image display unit 14 performs image display based on the display image signal received from the unevenness correction processing unit 12. For example, when the image display device 1 is realized by a liquid crystal display device, the image display unit 14 corresponds to a module including a liquid crystal panel, a timing controller, a source driver, a gate driver, and the like. Note that gamma correction processing for correcting the output characteristics of the image display unit 14 is also performed in the image display unit 14.

  The reference data holding unit 17 holds the target luminance data used when calculating the correction data held in the correction data holding unit 122 and the minimum luminance data before unevenness correction as reference data. The target luminance data and the minimum luminance data will also be described later.

  The communication processing unit 15 is connected to the control computer 4 and other image display devices 1 via the communication network 3 and has a function of transmitting / receiving data to / from each other.

  The control processing unit 16 controls control of each unit in the image display device 1 and controls reading and writing of data transmitted / received via the communication processing unit 15.

  FIG. 4 is a conceptual diagram of single unevenness correction processing executed in each of the image display devices 1-1 to 1-n constituting the multi-display system 10. Here, the single unevenness correction process is a process of correcting unevenness in brightness formed on the screen of the image display device 1 alone, and each image constituting the multi-display system 10 according to the present embodiment. It is assumed that each of the display devices 1-1 to 1-n has a function of executing a single unevenness correction process described below.

  In the following description, when the maximum luminance value in the image signal input to the image display device 1 is 100 and an image signal having a luminance value of 100 is input, the image signal is output on the screen of the image display device 1. Let the ideal value of the output brightness be 100. That is, when an image signal having a luminance value of 100 over the entire screen is input to the image display device 1 as a reference signal, the output luminance is ideally 100 over the entire screen of the image display device 1. And

  In FIG. 4, the image shown on the left side of each of the image display devices 1-1 to 1-n is the image when the reference signal is input to each of the image display devices 1-1 to 1-n. The brightness distribution Pi (where i = 1, 2,..., N) of the output brightness actually formed on the screens of the display devices 1-1 to 1-n is shown.

  For example, when the reference signal is input to the image display device 1-1, unlike the ideal, the region a <b> 1 whose output luminance is in the range of 95 to 99 and the output luminance in the range of 90 to 94. A luminance distribution P1 including a certain region a2 and a region a3 whose output luminance is in the range of 85 to 89 is formed. Also, when the reference signal is input to the image display device 1-2, unlike the ideal case, the region a2 in which the output luminance is in the range of 90 to 94 and the output luminance in the range of 85 to 89. A luminance distribution P2 including a certain region a3 and a region a4 whose output luminance is in the range of 80 to 84 is formed. As shown in these drawings, each of the image display devices 1-1 to 1-n constituting the multi-display system 10 inherently has a luminance distribution Pi with a different shape.

  Also, in FIG. 4, the diagram shown on the right side of each of the image display devices 1-1 to 1-n indicates that the output luminance is uniform over the entire screen in each of the image display devices 1-1 to 1-n. When the single unevenness correction processing is executed in FIG. 4, the luminance distributions Qi of the output luminances actually formed on the screens of the image display devices 1-1 to 1-n with respect to the input of the reference signal are respectively shown. Yes. The numerical value given to each luminance distribution Qi represents the value of the output luminance after the single unevenness correction processing.

  As described above, in order to make the output luminance uniform over the entire screen, the output luminance of the entire screen after the single unevenness correction processing is set to the lowest output luminance (hereinafter, referred to as the luminance distribution P of the output luminance before the single unevenness correction processing). (Referred to as “minimum output luminance”). Since this minimum output luminance is different for each of the image display devices 1-1 to 1-n constituting the multi-display system 10, the luminance distribution Q after the single unevenness correction processing is as shown in FIG. The image display devices 1-1 to 1-n are different.

  FIG. 5 is a diagram for explaining the correction data used in the single unevenness correction process. FIG. 5A is a diagram showing a luminance distribution P of the output luminance Lout with respect to the reference signal before the single unevenness correction process, and FIG. 5B is an output luminance Lout with respect to the reference signal after the single unevenness correction process. It is a figure which shows the luminance distribution Q. In FIG. 5, the lower left corner of the screen is the origin, the pixel position in the horizontal direction of the screen is x, and the pixel position in the vertical direction of the screen is y.

  Here, as shown in FIG. 5A, the luminance distribution P of the output luminance Lout with respect to the reference signal before the single unevenness correction processing is the region a1 in which the output luminance Lout is in the range of 95 to 99, and the output The image display device 1 formed by the region a2 having the luminance Lout in the range of 90 to 94 will be described as an example.

  In the following, regarding the pixel (x, y), the output luminance Lout with respect to the reference signal before the single unevenness correction processing is referred to as initial luminance Lo-i (x, y), and the reference signal after the single unevenness correction processing is described. The output luminance Lout with respect to is described as target luminance Lo-r (x, y). Note that this target luminance Lo-r (x, y) is a value that matches the minimum output luminance in all the pixels (x, y) in this embodiment, and is 90 in the example of FIG.

  As shown in FIG. 5A, the initial luminance Lo-i (x1, y1) of the pixel (x1, y1) is 90, which is the lowest output luminance, and the initial luminance Lo-i ( Assuming that x2, y1) is the highest output luminance 99 in the entire screen, in order to execute the single unit unevenness correction process so that the output luminance Lout is uniform over the entire screen, as shown in FIG. In addition, it is necessary to perform correction for other pixels so as to match the initial luminance Lo-i (x1, y1) = 90 of the pixel (x1, y1). Therefore, for example, in the pixel (x2, y1), the initial luminance Lo−i (x2, y1) = 99 is corrected to the target luminance Lo−r (x, y) = 90 by the single unevenness correction processing.

  FIG. 5C is a diagram showing the relationship of the output luminance Lout with respect to the input luminance Lin for the pixel (x1, y1). The solid line in FIG. 5C shows the luminance output characteristic curve C11 before the single unevenness correction processing of the pixel (x1, y1). As described above, the initial luminance Lo is obtained for the input luminance Lin = 100. -I (x1, y1) = 90.

  As shown in FIG. 5B, since the target luminance Lo-r (x, y) of each pixel (x, y) after the single unevenness correction processing is 90, in this pixel (x1, y1), Correction for the input luminance Lin = 100 is unnecessary.

  On the other hand, in the present embodiment, it is assumed that the gamma correction for correcting the output characteristics of the image display unit 14 is performed in the image display unit 14 as described above. Therefore, it is ideal that the output luminance Lout with respect to the input luminance Lin has a linear distribution as indicated by a broken line C12 in FIG.

  However, the actual luminance output characteristic curve C11 has a non-linear distribution as shown in FIG. Therefore, in order to bring the luminance output characteristic curve C11 closer to the ideal value indicated by the broken line C12, it is necessary to correct the intermediate luminance level where the input luminance Lin <100.

  FIG. 5D is a diagram showing a distribution curve C13 of the correction coefficient F (x1, y1) for converting the luminance output characteristic curve C11 into a linear distribution indicated by a broken line C12. According to FIG. 5D, the correction coefficient F (x1, y1) at Lin = 100 is 1.00, whereas the correction coefficient F (x1, y1) at the intermediate luminance, that is, Lin <100. It has a non-linear distribution.

  FIG. 5E is a diagram illustrating the relationship of the output luminance Lout with respect to the input luminance Lin for the pixel (x2, y1). The solid line in FIG. 5 (e) shows the luminance output characteristic curve C21 before the single pixel unevenness correction processing of the pixel (x2, y1). As described above, the initial luminance Lo for the input luminance Lin = 100. -I (x2, y1) = 99.

  As shown in FIG. 5B, since the target luminance Lo-r (x, y) of each pixel (x, y) after the single unevenness correction processing is 90, in this pixel (x2, y1), Correction is required to reduce the initial luminance Lo-i (x2, y1) = 99 to the target luminance Lo-r (x2, y1) = 90. Also in this pixel (x2, y1), according to the luminance output characteristic curve C21, the output luminance Lout with respect to the input luminance Lin has a non-linear distribution, and the luminance output characteristic is similar to the pixel (x1, y1). In order to bring the curve C21 closer to the ideal value indicated by the broken line C22, it is also necessary to correct an intermediate luminance level where the input luminance Lin <100.

  FIG. 5F is a diagram illustrating a distribution curve C23 of the correction coefficient F (x2, y1) for converting the luminance output characteristic curve C21 into a linear distribution indicated by a broken line C22. The distribution curve C23 of the correction coefficient F (x2, y1) for the pixel (x2, y1) is a non-linear curve similar to the distribution curve C13 of the correction coefficient F (x1, y1) for the pixel (x1, y1). However, in the pixel (x1, y1), the correction coefficient F (x1, y1) at Lin = 100 is 1.00, whereas in the pixel (x2, y1), the correction coefficient at Lin = 100. F (x2, y1) is 0.91 (≈90 / 99). Here, regarding the pixel (x, y), the correction coefficient F (x, y) at Lin = 100 is defined as the pixel correction coefficient Ks (x, y).

  By the way, the difference in luminance output characteristics between the pixel (x1, y1) and the pixel (x2, y1) as seen in FIG. 5C and FIG. In general, it also appears as a difference in overall gain. Therefore, the single unevenness correction process is divided into a common correction process based on a non-linear characteristic common to each pixel (x, y) and a pixel-specific correction process based on a gain difference between each pixel (x, y). Can think.

  The common correction processing is performed by using an approximation related to a higher-order function, a lookup table, and the like in common for each pixel (x, y), and data used for the calculation corresponds to common correction data. On the other hand, the pixel-specific correction processing is correction processing performed for each pixel based on the pixel correction coefficient Ks (x, y).

  In the present embodiment, each of the image display devices 1-1 to 1-n constituting the multi-display system 10 is individually subjected to optimum single unit unevenness correction processing at the time of manufacture, and is used for the single unit unevenness correction processing. The common correction data and the pixel correction coefficient Ks (x, y) are stored in advance in the correction data holding unit 122 as correction data. Further, it is assumed that the target luminance Lo-r (x, y) and the minimum output luminance are stored in advance in the reference data holding unit 17 as reference data.

  In the present embodiment, when the multi-display system 10 is constructed on the assumption that these various types of data are stored in advance in the image display devices 1-1 to 1-n, the pixel correction coefficient Ks (x, y) is reset for each of the image display devices 1-1 to 1-n to realize unevenness correction as the entire multi-display screen. The method will be described below.

  The unevenness correction processing includes luminance unevenness correction and color unevenness correction. However, in the image display apparatus 1 having the color unevenness correction function, unevenness in accordance with a predetermined target chromaticity in the initial single unevenness correction processing. Since the correction process can be performed, the unevenness correction when constructing the multi-display system 10 according to the present invention focuses only on the uneven brightness between the image display apparatuses 1. Further, in the actual unevenness correction process in the color image display device 1, correction data for each color component is originally necessary, but in this embodiment, the same correction process is performed for all color components. The following description will be made assuming only correction data relating to luminance.

  FIG. 6 shows the entire multi-display screen when the reference signal is input to each image display device 1 when the above-described single unit unevenness correction processing is executed in each image display device 1 constituting the multi-display system 10. It is a figure which shows an example of luminance distribution J1 in.

  In FIG. 6, the numerical value given to each image display device 1 represents the target luminance Lo−r (x, y) by the single unevenness correction processing of each image display device 1, that is, the minimum output luminance. As described above, even if the same reference signal is input to each image display device 1 constituting the multi-display system 10, a luminance step occurs at the boundary portion between the respective screens. Will occur.

  FIG. 7 is a diagram showing the luminance distribution J2 when the multi-screen unevenness correction process is performed so that the output luminance is uniform over the entire multi-display screen in the multi-display system 10 shown in FIG. In the following, as shown in FIG. 7, a specific method of multi-screen unevenness correction processing for making output luminance uniform over the entire multi-display screen will be described.

  8A and 8B are diagrams for explaining multi-screen unevenness correction processing performed in each image display device 1 constituting the multi-display system 10. In FIG. 8, the minimum output luminance is 90, that is, the target The image display apparatus 1 with luminance Lo−r (x, y) = 90 is shown as an example.

  FIG. 8A shows the luminance distribution P of the initial luminance Lo-i (x, y) before the single unevenness correction processing, and FIG. 8B shows the luminance distribution P shown in FIG. , Y = y1 represents a luminance distribution p1 in the pixel (x, y1) on the line. Similarly to FIG. 5A, the luminance distribution P has a region a1 in which the output luminance is in the range of 95 to 99 and a region a2 in which the output luminance is in the range of 90 to 94. As shown in b), the minimum output luminance in the luminance distribution P is 90.

  FIG. 8C shows the luminance distribution Q of the target luminance Lo-r (x, y) by the single unevenness correction processing, and FIG. 8D shows the luminance distribution Q shown in FIG. The luminance distribution q1 in the pixel (x, y1) on the line y = y1 is shown. As described above, after the single unevenness correction process, the output luminance Lout of each pixel (x, y) coincides with 90 which is the minimum output luminance.

  A distribution q2 of the pixel correction coefficient Ks (x, y1) for each pixel (x, y1) on the line y = y1 is shown in FIG. In other words, the luminance distribution q1 after the single unevenness correction processing shown in FIG. 8D is the target luminance distribution for obtaining the distribution q2 of the pixel correction coefficient Ks (x, y1) shown in FIG. But there is.

FIG. 8E shows only the distribution q2 of the pixel correction coefficient Ks (x, y1) relating to the pixel on the line y = y1, but the pixel correction coefficient Ks (x, y) is actually , It needs to be calculated as a distribution relating to all pixels (x, y) on the screen. This pixel correction coefficient Ks (x, y) is given by the following equation (1) using the initial luminance Lo-i (x, y) and the target luminance Lo-r (x, y).
Ks (x, y) = Lo-r (x, y) / Lo-i (x, y) (1)

  In the present embodiment, it is assumed that the correction data holding unit 122 of the unevenness correction processing unit 12 holds the pixel correction coefficient Ks (x, y) of all the pixels (x, y) in advance. However, in order to reduce the storage capacity, only the pixel correction coefficient Ks (x, y) of the representative pixel is stored at a predetermined pixel interval, and the pixel correction coefficient Ks (x, y) of the pixel between the representative pixels is stored. May be obtained by interpolation.

  Next, a procedure for obtaining the pixel correction coefficient Km (x, y) for the multi-screen unevenness correction process will be described. Here, the output luminance Lout with respect to the reference signal after the multi-screen unevenness correction processing is denoted as multi-target luminance Lo-m (x, y). FIG. 8F shows the luminance distribution R of the multi-target luminance Lo-m (x, y) by the multi-screen unevenness correction process, and FIG. 8G shows the luminance distribution R shown in FIG. The luminance distribution r1 in the pixel (x, y1) on the line y = y1 is shown.

  As shown in FIG. 8G, after the multi-screen unevenness correction process, correction is performed so as to match the lowest minimum output luminance among the minimum output luminances in the image display devices 1 constituting the multi-display system 10. . Therefore, in the case of the example shown in FIG. 6, the output luminance after the multi-screen unevenness correction process is 85 as shown in FIG.

FIG. 8H is a diagram showing a distribution r2 of pixel correction coefficients Km (x, y1) for multi-screen unevenness correction processing for each pixel (x, y1) on the line y = y1. The pixel correction coefficient Km (x, y) of each pixel (x, y) is expressed by the following equation using the initial luminance Lo-i (x, y) and the multi-target luminance Lo-m (x, y). It is calculated | required by (2).
Km (x, y) = Lo-m (x, y) / Lo-i (x, y) (2)

  Here, the distribution of the initial luminance Lo-i (x, y) of each pixel (x, y) needs to be measured with high accuracy in units of pixels, which is the factory or special facility of the image display device 1. Can only be implemented. Although a method of holding the luminance data measured during the single unevenness correction processing is also conceivable, it is not realistic because the data capacity to be held becomes enormous.

Therefore, in the present embodiment, the target brightness Lo-r (x, y) by the single unevenness correction process, the pixel correction coefficient Ks (x, y) for the single unevenness correction process, and the multi-target brightness by the multi-screen unevenness correction process. Using Lo-m (x, y), a pixel correction coefficient Km (x, y) for multi-screen unevenness correction processing is calculated by the following equation (3).
Km (x, y)
= Lo-m (x, y) / {Lo-r (x, y) / Ks (x, y)}
= Lo-m (x, y) * Ks (x, y) / Lo-r (x, y) (3)

  FIG. 9 is a flowchart showing a processing procedure of multi-screen unevenness correction processing according to the present embodiment. When the processing is started, in step s1, the control computer 4 applies the correction data stored in the correction data holding unit 122 and the reference data holding unit 17 to each of the image display devices 1-1 to 1-n. A command to transmit the reference data stored in the control computer 4 to the control computer 4 is given. Accordingly, when the control computer 4 acquires the correction data and the reference data from each of the image display devices 1-1 to 1-n, the process proceeds to step s2.

  In step s2, the control computer 4 matches the minimum value among the minimum output luminances of the image display devices 1-1 to 1-n based on the minimum luminance data included in the reference data. Then, the multi-target luminance Lo-m (x, y) by the multi-screen unevenness correction process is set, and the process proceeds to step s3.

  In step s3, the control computer 4 includes the multi-target luminance Lo-m (x, y) set in step s2 and the correction data acquired in step s1 for each of the image display devices 1-1 to 1-n. Multi-screen unevenness correction processing by the above equation (3) based on the pixel correction coefficient Ks (x, y) to be obtained and the target luminance Lo-r (x, y) included in the reference data acquired in step s1. The pixel correction coefficient Km (x, y) for use is calculated, and the process proceeds to step s4.

  In step s4, the control computer 4 uses the pixel correction coefficient Km (x, y) calculated in step s3 and the multi-target luminance Lo-m (x, y) set in step s2 to correspond to the image display device. 1-1 to 1-n, and proceeds to step s5.

  In step s5, the control processing unit 16 of each of the image display apparatuses 1-1 to 1-n holds correction data according to the pixel correction coefficient Km (x, y) received from the control computer 4 via the communication processing unit 15. The pixel correction coefficient Ks (x, y) stored in the unit 122 is updated, and the target brightness stored in the reference data holding unit 17 is also obtained by the multi-target brightness Lo-m (x, y) received together. Lo-r (x, y) is updated, and the process proceeds to step s6.

  In step s <b> 6, the correction calculation unit 123 of each of the image display devices 1-1 to 1-n updates the updated pixel given from the correction data holding unit 122 to the input image signal input from the input image processing unit 11. Using the correction coefficient Km (x, y) and the common correction data, correction calculation processing is performed for each pixel, and is output to the image display unit 14 as a display image signal. As a result, the image after the multi-screen unevenness correction process is displayed on the screen of each of the image display apparatuses 1-1 to 1-n, and the process ends.

  As described above, according to the present embodiment, when the multi-display system 10 is configured by holding the correction data and the reference data in advance in each image display device 1, the luminance / chromaticity data is stored. Display unevenness appearing on the multi-display screen can be easily corrected without performing re-measurement.

  Further, according to the present embodiment, in the multi-screen unevenness correction process, the newly calculated pixel correction coefficient Km (x, y) and multi-target luminance Lo-m (x, y) are transmitted to each image display device 1. Since the pixel correction coefficient Ks (x, y) and the target luminance Lo-r (x, y) that are already held are held in place, the arrangement of the multi-display system 10 is changed. When changing the target luminance distribution, it is possible to reset the correction data in the same procedure.

  In the above embodiment, as described above, the control computer 4 is provided as a device independent of the image display device 1, but the control computer 4 is configured to display a plurality of images constituting the multi-display system 10. By being built in one image display device 1 of the devices 1, it is possible to construct the multi-display system 10 with only the image display device 1 and perform the multi-screen unevenness correction process.

(Second Embodiment)
In the multi-display system 10 according to the first embodiment, the unevenness correction processing is performed in accordance with the condition that the output luminance is uniform over the entire multi-display screen. In this case, the output luminance of the entire screen is determined by each image display device. There is a drawback that it is lowered in accordance with the minimum value of the minimum output luminance of 1.

  On the other hand, in actual use of the image display device 1, it may not always be necessary to make the output luminance of the entire multi-display screen uniform. Therefore, the multi-display system 10 according to the present embodiment is configured to perform unevenness correction processing by providing a luminance gradient over the entire multi-display screen.

  In the following description, in the multi-display screen, the output brightness at the center is set higher than that at the periphery, taking advantage of the fact that the center is more noticeable than the periphery. A case will be described as an example where multi-screen unevenness correction processing is performed so as to create a luminance gradient that smoothly decreases the output luminance.

  Note that the method of setting the luminance gradient is not limited to this, and for example, the image display device 1 disposed at the upper part looks darker than the image display device 1 disposed at the lower part due to a difference in viewing angle. In order to solve this problem, it is conceivable that luminance gradients having different shapes are set according to applications, such as setting the output luminance higher in the upper image display device 1.

  Here, in the first embodiment, each of the image display apparatuses 1-1 to 1-n constituting the multi-display system 10 executes the single unevenness correction process under the condition that the output luminance is uniform over the entire screen. In this embodiment, each of the image display devices 1-1 to 1-n constituting the multi-display system 10 sets the output brightness of the central portion higher than that of the peripheral portion. It is assumed that it has a function of executing a single unevenness correction process so as to create a luminance gradient that smoothly changes the output luminance from the peripheral portion to the peripheral portion.

  FIG. 10 is a conceptual diagram of single unevenness correction processing executed in each of the image display devices 1-1 to 1-n constituting the multi-display system 10. In FIG. 10, the diagram shown on the left side for each of the image display devices 1-1 to 1-n is the same as the diagram shown on the left side for each of the image display devices 1-1 to 1-n in FIG. Therefore, the description is omitted.

  In FIG. 10, the right side of each of the image display devices 1-1 to 1-n shows a case where the single unevenness correction process is executed according to the above-described conditions in each of the image display devices 1-1 to 1-n. The luminance distribution Ti of the output luminance actually formed on the screens of the image display devices 1-1 to 1-n with respect to the input of the reference signal is shown. In this way, the brightness gradient of the output brightness on the screen after the single unevenness correction processing is different for each of the image display devices 1-1 to 1-n constituting the multi-display system 10.

  FIG. 11 is a diagram for explaining correction data used for the single unevenness correction processing. FIG. 11A shows the luminance distribution P of the initial luminance Lo-i (x, y) before the single unevenness correction processing, and FIG. 11B shows the luminance distribution P shown in FIG. , Y = y1 represents the luminance distribution p1 at the pixel (x, y1) on the line. Note that FIG. 11A and FIG. 11B are the same as FIG. 8A and FIG.

  FIG. 11C shows the luminance distribution T of the target luminance Lo-r (x, y) by the single unevenness correction processing, and FIG. 11D shows the luminance distribution T shown in FIG. 2 shows the luminance distribution t1 in the pixels on the line y = y1. As shown in FIG. 11D, the target luminance Lo-r (x, y) by the single unevenness correction processing is set so that the output luminance Lout at the center is high, and the output luminance from the central portion to the peripheral portion. Lout decreases smoothly. Specifically, based on the luminance distribution P shown in FIG. 11A, the output luminance Lout in the central portion is set to 95, which is the lowest output luminance in the region a1, and the output is output around the central portion. An area a2 in which the luminance Lout is in the range of 90 to 94 and an area a3 in which the output luminance Lout is in the range of 85 to 89 are provided. In each of the areas a2 and a3, the output luminance is proportional to the distance from the center. A luminance gradient is set so that Lout decreases.

  FIG. 12 shows the entire multi-display screen when the reference signal is input to each image display device 1 when the above-described single unit unevenness correction process is executed in each image display device 1 constituting the multi-display system 10. It is a figure which shows an example of luminance distribution J3 in. When the single unevenness correction process is executed in each image display device 1, even if the display characteristics of all the image display devices 1 are the same, as shown in FIG. Unevenness will occur.

  Each image display device 1 constituting the multi-display system 10 has individual differences in the luminance distribution P of the output luminance, and the minimum output luminance value in each image display device 1 is the image display device as shown in FIG. 1 ability value. Therefore, in the multi-display system 10, the multi-screen unevenness is set so that the output luminance at the central portion of the multi-display screen is higher than that at the peripheral portion, and a luminance gradient that smoothly decreases the output luminance from the central portion to the peripheral portion. When performing the correction process, the image display device 1 having a high minimum output luminance is arranged in a place where a high output luminance is required, and the image display device having a low minimum output luminance is provided in a place where a relatively low output luminance may be used. By arranging 1, the increase in output luminance performance of the multi-display system 10 as a whole can be measured as compared with the case where the arrangement order is not considered in this way.

  FIG. 13 shows the luminance distribution V of the entire multi-display screen when the image display device 1 is arranged according to a predetermined rule based on the arrangement of the image display apparatus 1 with the highest minimum output luminance at the center of the multi-display screen. It is a figure which shows an example, and shows the example which rearranged each image display apparatus 1 in the multi-display system 10 shown in FIG. 6 on the basis of arrange | positioning the image display apparatus 1 with the highest minimum output brightness in the center part. ing.

  FIG. 14 is a diagram showing a specific arrangement order when rearrangement is performed based on the arrangement of the image display device 1 with the highest minimum output luminance at the center, and the image display with the highest minimum output luminance is performed in numerical order. It is arranged from the device 1.

  This order is determined uniquely according to the final luminance gradient, and the method is prepared by, for example, preparing a predetermined arrangement pattern for each possible configuration of the multi-display system 10. Alternatively, the arrangement may be automatically determined based on a certain rule.

  For example, if the order of the distance from the center to the highest brightness is assigned and the distance from the center is equal, the relative positional relationship from the center point, for example, left This is realized by determining the arrangement order in the priority order of> right> bottom> upper, and FIG. 14 illustrates the case where the arrangement order is determined according to this rule. Note that this arrangement order determination method is not limited to the above-described method, and any other method may be used as long as it corresponds to the luminance distribution targeted for unevenness correction.

  In the multi-display system 10 according to the present embodiment, each image display device 1 is connected to the control computer 4 via the communication network 3 before the image display devices 1 are actually arranged. 4 obtains the minimum luminance data stored in the reference data holding unit 17 from each image display device 1, and arranges the image display devices 1 according to the rule shown in FIG. 14 based on the acquired minimum luminance data. The arrangement order is determined when arranging.

  As described above, in the present embodiment, before the multi-display system 10 is constructed, the arrangement order of the image display devices 1 is determined so that the output luminance performance of the multi-display system 10 as a whole is improved. As a result, the number of installation work steps can be reduced.

  Next, a specific method for setting the distribution of the multi-target luminance Lo-m (X, Y) by the multi-screen unevenness correction process will be described.

  FIG. 15 is a diagram for explaining an example of a luminance distribution U by a luminance gradient that is ideal in a multi-display system 10 constructed by arranging 25 image display devices 1 in a horizontal direction X and a vertical direction Y. It is. Based on the ideal luminance distribution U, the distribution of the multi-target luminance Lo-m (X, Y) is set so as not to exceed the minimum output luminance of each image display device 1. In FIG. 15, the lower left of the screen in the image display device 1 arranged at the lower left is the origin, the horizontal pixel position is X, and the vertical pixel position is Y.

  In the ideal luminance distribution U shown in FIG. 15A, the pixels in the screen of the image display device 1 arranged at the center are uniformly set to output luminance Lout = 100, and the image display device 1 arranged at the center The distribution is such that the output luminance Lout varies linearly from the boundary with the image display device 1 arranged in the periphery to the pixels in the most peripheral portion of the multi-display screen.

  FIG. 15B shows the ideal luminance distribution u1 in the pixel (X, Y1) on the line Y = Y1 in the ideal luminance distribution U shown in FIG. FIG. 15C shows an ideal luminance distribution u2 in the pixel (X, Y2) on the line Y = Y2 in the ideal luminance distribution U shown in FIG.

  As shown in FIG. 15, the ideal luminance distribution U uses a combination of linear functions having different shapes for each predetermined pixel region. Note that FIG. 15B shows a one-dimensional ideal luminance distribution u1 when Y = Y1, but as shown in the difference between FIG. 15B and FIG. The luminance distribution U depends not only on the X direction but also on the Y direction, and is actually defined as a two-dimensional function depending on the pixel position (X, Y). Here, regarding the pixel (X, Y), the ideal output luminance Lout with respect to the reference signal after the multi-screen unevenness correction processing is referred to as ideal luminance Lo-u (X, Y).

  Further, the ideal luminance distribution U does not have to be a combination of linear functions as shown in FIGS. 15B and 15C, but may be a higher order function or a combination of higher order functions. May be. However, in order to measure the simplification of the arithmetic processing and the reduction of the storage capacity, it is desirable to be realized by a simpler function.

  FIG. 16 is a diagram showing the luminance distribution V when the minimum output luminance is uniformly distributed on each screen in each image display device 1 constituting the multi-display system 10, and FIG. Corresponds to FIG.

  This luminance distribution V indicates the distribution of the output luminance Lout that can be guaranteed at a minimum for each pixel (X, Y) on the multi-display screen. The multi-target luminance Lo-m (X, Y) by the multi-screen unevenness correction process. Must be set so as not to exceed the luminance distribution V in all pixels (X, Y).

  FIG. 16B shows the luminance distribution v1 in the pixel (X, Y1) on the line Y = Y1 in the luminance distribution V shown in FIG. FIG. 16C shows the luminance distribution v2 in the pixel (X, Y2) on the line Y = Y2 in the luminance distribution V shown in FIG. In FIG. 16B and FIG. 16C, the broken line v3 indicates the initial luminance Lo-i (x, y before the single unevenness correction processing in each image display device 1 on the line Y = Y1 or Y = Y2. ). Here, in the luminance distribution V shown in FIG. 16A, the minimum output luminance relating to the pixel (X, Y) is described as the minimum luminance M (X, Y).

In this embodiment, the minimum luminance M (X, Y) is compared with the ideal luminance Lo-u (X, Y) in all the pixels (X, Y) on the multi-display screen, and based on the comparison result. By modifying the ideal luminance distribution U shown in FIG. 15A, the distribution of the multi-target luminance Lo-m (X, Y) is set. The multi-target luminance Lo-m (X, Y) is obtained so as to satisfy the following expression (4) at all pixel positions.
Lo−m (X, Y) ≦ M (X, Y) (4)

However, the multi-target luminance Lo-m (X, Y) is actually calculated depending on the relationship with the ideal luminance Lo-u (X, Y). For example, when the multi-target luminance Lo-m (X, Y) is defined as being proportional to the ideal luminance Lo-u (X, Y), and the proportionality coefficient is α, the multi-target luminance Lo-m (X, Y) Y) can be represented by the following equation (5).
Lo−m (X, Y) = α × Lo−u (X, Y) (5)

Therefore, the following relational expression (6) is obtained from the above expressions (4) and (5).
α ≦ M (X, Y) ÷ Lo−u (X, Y) (6)

  That is, for all the pixels (X, Y) on the multi-display screen, the minimum value among the quotients obtained by dividing the minimum luminance M (X, Y) by the ideal luminance Lo-u (X, Y) is obtained. By using the proportional coefficient α and the ideal luminance Lo-u (X, Y), the optimum multi-target luminance Lo-m (X, Y) is calculated based on the equation (5). Distribution can be set.

  FIG. 17 is a diagram showing a luminance distribution W of target luminance set by the multi-screen unevenness correction processing set based on the ideal luminance distribution U shown in FIG. 15 and the luminance distribution V of the lowest output luminance shown in FIG. . In the example shown in FIG. 17, a case where the proportionality coefficient α is calculated as 0.94 is shown.

  FIG. 17B shows the luminance distribution w1 in the pixel (X, Y1) on the line Y = Y1 in the luminance distribution W shown in FIG. FIG. 17C shows the luminance distribution w2 in the pixel (X, Y2) on the line Y = Y2 in the luminance distribution W shown in FIG. As shown in FIGS. 17B and 17C, the luminance distribution W of the multi-target luminance Lo-m (X, Y) is set so as not to exceed the luminance distribution V of the lowest output luminance.

  When the luminance distribution W of the multi-target luminance Lo-m (X, Y) as the entire multi-display screen is set in this manner, the luminance distribution W of the multi-target luminance Lo-m (X, Y) is set. Thus, the multi-target luminance Lo-m (x, y) in each of the image display devices 1-1 to 1-n is obtained.

  When the multi-target luminance Lo-m (x, y) of each of the image display devices 1-1 to 1-n is obtained, the multi-target luminance Lo-m (x, y) and the same as in the first embodiment. , Pixel correction coefficient Km (for multi-screen unevenness correction processing) using target brightness Lo-r (x, y) for single unevenness correction processing and pixel correction coefficient Ks (x, y) for single unevenness correction processing. x, y) is calculated by the above equation (3).

  In the multi-screen unevenness correction process according to the present embodiment, before the process is started, each of the image display devices 1-1 to 1-n constituting the multi-display system 10 has a central portion as shown in FIG. Are arranged based on the arrangement of the image display device 1 having a high minimum output luminance.

  The multi-screen unevenness correction processing procedure according to the present embodiment is different from the multi-screen unevenness correction processing procedure according to the first embodiment shown in FIG. Since the other steps are the same, the illustration is omitted, and only the steps that are different will be described below.

  In the present embodiment, when correction data and reference data are acquired from the image display devices 1-1 to 1-n in step s1, the control computer 4 uses the minimum luminance data included in the reference data. Based on the ideal luminance distribution U, first, the proportionality coefficient α is calculated to set the luminance distribution W of the multi-target luminance Lo-m (X, Y) as the entire multi-display screen.

  Then, based on the luminance distribution W of the multi-target luminance Lo-m (X, Y), the control computer 4 uses the multi-target luminance Lo-m (x, y) in each of the image display devices 1-1 to 1-n. ) And proceeds to step s3. Thereafter, processing is performed according to the flowchart shown in FIG. It is assumed that data indicating the ideal luminance distribution U is held in the control computer 4 in advance.

  As described above, according to the present embodiment, when the multi-display system 10 is configured by holding the correction data and the reference data in advance in each image display device 1, the luminance / chromaticity data is stored. Display unevenness appearing on the multi-display screen can be easily corrected without performing re-measurement.

In the above embodiment, the multi target luminance Lo-m (X, Y) is defined to be proportional to the ideal luminance Lo-u (X, Y), but the multi target luminance Lo-m (X , Y) and ideal luminance Lo-u (X, Y) are not limited to such a proportional relationship, and a predetermined intercept β may be adjusted as shown in the following equation (7). .
Lo−m (X, Y) = Lo−u (X, Y) + β (7)

In this case, the following relational expression (8) is obtained from the expressions (4) and (7).
β ≦ M (X, Y) −Lo−u (X, Y) (8)

  That is, for all the pixels (X, Y) on the multi-display screen, the minimum value among the values obtained by subtracting the ideal luminance Lo-u (X, Y) from the minimum luminance M (X, Y) is calculated. By obtaining the intercept β, the distribution of the optimum multi-target luminance Lo-m (X, Y) based on the equation (7) by the intercept β and the ideal luminance Lo-u (X, Y). May be set.

  In the above embodiment, a program for executing processing by the control computer 4 is stored in a storage device such as a semiconductor memory or HDD (Hard Disk Drive) mounted on the control computer 4. It is not limited to such a storage device, and may be recorded on a computer-readable recording medium. The recording medium may be a recording medium that can be read by providing a program reading device as an external storage device (not shown) and inserting the recording medium therein, or may be a storage device of another device. .

  Any recording medium may be used as long as the program stored in the recording medium is accessed from a computer and executed. In other words, any recording medium may be used as long as the program is read from the recording medium, the read program is stored in the program storage area of the storage device, and the program is executed. Further, it may be downloaded from another device via a communication network and stored in the program storage area. The download program is stored in advance in a storage device of a computer, or installed in a program storage area from another recording medium.

  The recording medium configured to be separable from the main body is, for example, a tape-based recording medium such as a magnetic tape / cassette tape, a disk-based recording medium such as a floppy (registered trademark) disk, or a magnetic disk such as a flexible disk / hard disk. Disc or CD-ROM (Compact Disk Read Only Memory) / MO (Magneto Optical disk) / MD (Mini Disk) / DVD (Digital Versatile Disk) and other optical disk disc recording media, IC (Integrated Circuit) cards (memory) Card-based recording media such as optical cards, etc., or fixed programs including mask ROM / EPROM (Erasable Programmable Read Only Memory) / EEPROM (Electrically Erasable Programmable Read Only Memory) / semiconductor memory such as flash ROM May be a recording medium carrying the.

DESCRIPTION OF SYMBOLS 1 Image display apparatus 2 Image signal generation apparatus 3 Communication network 4 Control computer 10 Multi display system 11 Input image processing part 12 Unevenness correction processing part 14 Image display part 15 Communication processing part 16 Control processing part 17 Reference data holding part 121 Pixel position Determination unit 122 Correction data holding unit 123 Correction calculation unit

Claims (7)

A multi-display system that forms a multi-display screen by arranging a plurality of image display devices that can display images,
An arithmetic processing unit that calculates correction data for multi-screen for correcting variations in luminance in the multi-display screen.
Each image display device
A correction data storage unit in which correction data for own screen for correcting variations in luminance in the screen of the own device is stored in advance;
A target luminance data storage unit in which self-screen target luminance data indicating the target luminance after correction by the self-screen correction data is stored;
A correction calculation unit that corrects an image signal input from the outside using the correction data for the self-screen, and generates a display image signal;
An image display unit for displaying an image based on the display image signal generated by the correction calculation unit;
A communication processing unit that transmits and receives data to and from the arithmetic processing unit,
The arithmetic processing unit obtains self-screen correction data and self-screen target brightness data from each image display device, and calculates a target brightness for a multi-display screen based on the self-screen target brightness data of each image display device. In addition to calculating, for each image display device, multi-screen correction data is calculated using the corresponding self-screen correction data so that the calculated target luminance is obtained, and the multi-screen correction data is converted into the corresponding image. To the display device,
When the communication processing unit of the image display device receives the multi-screen correction data from the arithmetic processing unit, the correction calculation unit of each image display device converts the image signal input from the outside into the correction data for the multi-screen. A multi-display system characterized in that a display image signal is generated by correction using the display. The arithmetic processing unit transmits multi-screen target luminance data indicating target luminance for the multi-display screen together with the multi-screen correction data to each image display device,
Each image display device includes a control unit, and when the communication processing unit of the device receives the multi-screen correction data and the multi-screen target luminance data from the arithmetic processing unit, the control unit 2. The multi-display according to claim 1, wherein the correction data is stored in the correction data storage unit of the device itself, and the multi-screen target luminance data is stored in the target luminance data storage unit of the device. system.   The multi-display system according to claim 1, wherein the arithmetic processing unit is built in one of the plurality of image display devices.   When the arithmetic processing unit arranges the image display devices side by side so that the target luminance increases along a predetermined direction on the multi-display screen based on the target screen target luminance data acquired from the image display devices. The multi-display system according to any one of claims 1 to 3, wherein the arrangement order is determined. Multi-screen correction for correcting variations in luminance in a multi-display screen composed of a plurality of image display devices arranged side by side and each screen of the plurality of image display devices arranged side by side An image display device used in a multi-display system including an arithmetic processing unit that calculates data,
A correction data storage unit in which correction data for own screen for correcting variations in luminance in the screen of the own device is stored in advance;
A target luminance data storage unit in which self-screen target luminance data indicating the target luminance after correction by the self-screen correction data is stored;
A correction calculation unit that corrects an image signal input from the outside using the correction data for the self-screen, and generates a display image signal;
An image display unit for displaying an image based on the display image signal generated by the correction calculation unit;
A communication processing unit that transmits and receives data to and from the arithmetic processing unit,
When the communication processing unit receives the multi-screen correction data from the arithmetic processing unit, the correction calculation unit corrects an image signal input from the outside using the multi-screen correction data, and displays the correction data. An image display device that generates an image signal. Multi-screen correction for correcting variations in luminance in a multi-display screen composed of a plurality of image display devices arranged side by side and each screen of the plurality of image display devices arranged side by side A correction data storage unit that stores in advance correction data for self-screen for correcting variations in luminance in the screen of the image display device, and a calculation data storage unit that calculates data. A screen control method in a multi-display system having a target brightness data storage unit in which target brightness data for self-screen indicating a target brightness after correction by the correction data for use is stored,
The arithmetic processing unit obtains correction data for own screen and target luminance data for own screen from each image display device; and
The arithmetic processing unit calculates a target luminance for a multi-display screen based on the target screen target luminance data of each image display device; and
A correction data calculating step in which the arithmetic processing unit calculates correction data for multi-screen using corresponding correction data for own screen so that the calculated target luminance is obtained for each image display device;
A data transmission step in which the arithmetic processing unit transmits the calculated multi-screen correction data to a corresponding image display device;
When each image display device receives the multi-screen correction data from the arithmetic processing unit, the image display device generates a display image signal by correcting an externally input image signal using the multi-screen correction data. A screen control method comprising a correction step.   A program for causing a computer to execute the data acquisition step, the target luminance calculation step, the correction data calculation step, and the data transmission step according to claim 6.