Image display device, image display method, and image display program

Abstract

The present invention provides an image display device, an image display method, and an image display program which make it possible to suppress display abnormalities at an end of a display image in an image display device that is formed by layering a plurality of display panels. Provided is an image display device in which a plurality of display panels are layered and disposed and which displays an image on each of the display panels, said image display device comprising: a first display panel which is disposed at a position close to a viewer; a second display panel which is disposed at a position farther away from the viewer than the first display panel; and an image generation unit which, on the basis of input image data, generates first image data that is for displaying a first image in an image display region of the first display panel and second image data that is for displaying a second image in an image display region of the second display panel. The image display region of the second display panel is larger than the image display region of the first display panel, and the image display region of the second display panel includes a first display region and a second display region which is positioned outside the first display region. The image generation unit uses, as a reference, a boundary pixel region which is positioned near a boundary between the first and second display regions, and uses a first pixel group including a plurality of pixels which are aligned continuously in a first direction toward the inside of the first display region to generate a second pixel group including a plurality of pixels which are aligned continuously in a second direction toward the outside of the second display region. The manner in which pixel values change in the second direction for the second pixel group is the same as the manner in which pixel values change in the first direction for the first pixel group.

Description

Technical Field

[0001] The present invention relates to an image display device, an image display method, and an image display program.

Background Art

[0002] Conventionally, as a technique for improving the contrast of a liquid crystal display device, a technique has been proposed in which two display panels are overlapped and images are displayed on the respective display panels based on an input video signal (see, for example, Patent Document 1). Specifically, for example, a color image is displayed on the front display panel (observer side) of two display panels arranged front and back, and a black-and-white image is displayed on the rear display panel (backlight side) to improve the contrast.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above conventional liquid crystal display device, for example, in two display panels arranged front and back, when the end of the display screen is viewed from an oblique direction, due to the influence of the non-image display area of the display panel arranged on the rear side, there is a problem that the end of the display image is not displayed normally. For example, the end of the display image may become dark and may appear in a state where the original end of the display image is missing (a state of missing image). Also, the end of the display image may become bright and may appear in a state where the original end of the display image is shining (a state of light leakage).

[0005] An object of the present invention is to provide an image display device, an image display method, and an image display program capable of suppressing display abnormalities at the ends of a display image in an image display device configured by overlapping a plurality of display panels. [Means for solving the problem]

[0006] According to the present invention, an image display device with the following configuration is provided. [1] An image display device comprising a plurality of display panels arranged in a superimposed manner, each of which displays an image, comprising: a first display panel positioned closer to the observer; a second display panel positioned further from the observer than the first display panel; and an image generation unit that generates first image data for displaying a first image in the image display area of ​​the first display panel and second image data for displaying a second image in the image display area of ​​the second display panel based on input image data, wherein the image display area of ​​the second display panel is larger than the image display area of ​​the first display panel. Image display device, wherein the image display area of ​​the second display panel includes a first display area and a second display area located outside the first display area, and the image generation unit generates a second pixel group including a plurality of pixels arranged continuously in a second direction toward the outside of the second display area, using a first pixel group including a plurality of pixels arranged continuously in a first direction toward the inside of the first display area, with reference to a boundary pixel area located near the boundary of the first and second display areas, and the manner of change of pixel values ​​in the second direction for the second pixel group is the same as the manner of change of pixel values ​​in the first direction for the first pixel group.

[0007] According to the present invention, in a second display panel positioned further from the observer than the first display panel, the second pixel group is generated using the first pixel group, with reference to a boundary pixel region located near the boundary between the first and second display regions, such that the pattern of change in pixel values ​​in the second direction for the second pixel group is the same as the pattern of change in pixel values ​​in the first direction for the first pixel group. This makes it possible to suppress display abnormalities at the edges of the displayed image when an observer views the edges of the display screen of the image display device from an oblique direction.

[0008] The following are examples of various embodiments of the present invention. The embodiments shown below can be combined with each other. An image display device as described in [2][1], wherein the image generation unit generates an image for display in the first display area, which is an enlarged image based on the input image data. The image display device described in [3][2], wherein the image to be displayed in the first display area is an image obtained by enlarging the image based on the input image data with an accuracy of less than 1 pixel. An image display device according to any one of [4][1] to [3], wherein the boundary pixel region consists of one or more pixels located along the first direction within the first display region from the boundary between the first and second display regions. An image display device according to any one of [5][1] to [3], wherein the boundary pixel region comprises one or more pixels located along the first direction within the first display region from the boundary of the first and second display regions, and one or more pixels located along the second direction within the second display region from the boundary of the first and second display regions. [6] An image display method for displaying an image on each of a plurality of display panels arranged in a superimposed manner, comprising an image generation step of generating, based on input image data, first image data for displaying a first image in the image display area of ​​a first display panel positioned closer to the observer, and second image data for displaying a second image in the image display area of ​​a second display panel positioned further from the observer than the first display panel, wherein the image display area of ​​the second display panel is larger than the image display area of ​​the first display panel, and the image display area of ​​the second display panel includes a first display area and a second display area located outside the first display area, and in the image generation step, a second pixel group is generated using a first pixel group including a plurality of pixels arranged continuously in a first direction toward the outside of the second display area, with reference to a boundary pixel area located near the boundary of the first and second display areas, and using a first pixel group including a plurality of pixels arranged continuously in a first direction toward the inside of the first display area, wherein the mode of change of pixel values ​​in the second direction for the second pixel group is the same as the mode of change of pixel values ​​in the first direction for the first pixel group. [7] An image display program that causes a processor to execute the image display method described in [6]. [Effects of the Invention]

[0009] According to the present invention, in an image display device configured by stacking multiple display panels, display abnormalities at the edges of the displayed image can be suppressed. [Brief explanation of the drawing]

[0010] [Figure 1] This is a block diagram showing the functional configuration of an image display device 10 according to an embodiment of the present invention. [Figure 2] This is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e0. [Figure 3] This is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e0. [Figure 4] This is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e1. [Figure 5] This figure shows examples of image display areas A0, A1, and A2 corresponding to widths W0, W1, and W2, respectively, when the second display panel 32 is viewed from the normal direction of the stacked display panel. [Figure 6] This diagram illustrates the concept of displaying a second image, which was generated with the size of image display area A0, by scaling it up to the size of the sum of image display area A0 and image display area A1. [Figure 7] This is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e0 when a second image generated with the size of image display area A0 is displayed, and image display areas A1 and A2 are displayed entirely in black (solid black). [Figure 8] This is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e0 when a second image, generated with the size of image display area A0, is enlarged to the size of the sum of image display area A0 and image display area A1, and image display area A2 is displayed as completely black (solid black). [Figure 9] This is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e1, when the observer is looking at the edge of the stacked display panel. [Figure 10] This is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e2, when the observer is looking at the edge of the stacked display panel. [Figure 11] This diagram illustrates an example of a predetermined second extension process. [Figure 12] This diagram illustrates an example of a predetermined second extension process. [Figure 13] This diagram illustrates an example of a predetermined second extension process. [Figure 14] Figure 14A is an example of an image showing the edge of the image display area A1 after a predetermined first expansion process has been performed by the first expansion unit 25. Figure 14B is an example of an image showing the edge of the image display area A1 and the image display area A2 after a predetermined second expansion process has been performed by the second expansion unit 26, using the image shown in Figure 14A. Figure 14C is an example of an image showing the edge of the image display area A1 and the image display area A2 after a process different from the predetermined second expansion process has been performed by the second expansion unit 26, using the image shown in Figure 14A. [Figure 15] Figure 15A is an example of an image showing the edge of the image display area A1 after a predetermined first expansion process has been performed by the first expansion unit 25. Figure 15B is an example of an image showing the edge of the image display area A1 and the image display area A2 after a predetermined second expansion process has been performed by the second expansion unit 26, using the image shown in Figure 15A. Figure 15C is an example of an image showing the edge of the image display area A1 and the image display area A2 after a process different from the predetermined second expansion process has been performed by the second expansion unit 26, using the image shown in Figure 15A. [Figure 16] This is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e1, after a predetermined second expansion process has been performed by the second expansion unit 26 and the observer is looking at the edge of the stacked display panel. [Figure 17]After a predetermined second expansion process by the second expansion unit 26, when an observer views an end of the stacked display panel, it is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the viewpoint e2 of the observer. [Figure 18] It is a flowchart showing an example of the image display process performed by the image display device 10. [Figure 19] It is a diagram for explaining the interpolation process executed in the first expansion process when the first expansion process by the first expansion unit 25 is executed after the execution of the second expansion process by the second expansion unit 26.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each of the characteristic matters shown in the following embodiments can be combined with each other. Also, an invention can be established independently for each characteristic matter.

[0012] FIG. 1 is a block diagram showing the functional configuration of an image display device 10 according to an embodiment of the present invention. As shown in FIG. 1, the image display device 10 is a color liquid crystal display device using three colors of RGB, and includes an image generation unit 20 and a display unit 30 as its configuration. The image generation unit 20 and the display unit 30 are connected to each other so as to be communicable via a signal cable.

[0013] Each component of the image display device 10 may be implemented by software or by hardware. When implemented by software, various functions can be realized by the CPU executing a computer program. The program may be stored in an internal memory unit or in a computer-readable non-temporary recording medium. Alternatively, the program may be read from an external memory unit and implemented by so-called cloud computing. When implemented by hardware, it can be implemented by various circuits such as ASICs, FPGAs, or DRPs (Dynamically Reconfigurable Processors). In this embodiment, various information and concepts encompassing it are handled, which are represented by high and low signal values ​​as a set of binary bits composed of 0s and 1s, and communication and calculations can be performed by the above-described software or hardware configurations.

[0014] The image display device 10 is equipped with a contrast enhancement technology that improves the contrast of images displayed by the display unit 30. This technology involves superimposing two display panels and displaying an image on each panel based on input image data (for example, an input video signal). Specifically, the contrast enhancement technology improves the contrast of the displayed image by displaying a color image on the front (observer side) of two display panels arranged front to back, and a black and white image on the rear (backlight side) display panel.

[0015] Figure 2 is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e0 (the ideal viewpoint which is the sweet spot, the same applies hereinafter). As shown in Figure 2, the display unit 30 comprises a light source 33 (backlight) located on the back side of the display unit 30 and a plurality of display panels arranged in overlapping (stacked) configurations. The display unit 30 comprises two liquid crystal panels as the plurality of display panels: a first display panel 31 located on the front side of the display unit 2, i.e., close to the observer, and a second display panel 32 located between the first display panel 31 and the light source 33.

[0016] When viewed from the observer's viewpoint e0, which is located in front of the display unit 30, the second display panel 32 is positioned further from the observer than the first display panel 31. In contrast enhancement technology, it is necessary for the light L emitted from the end of the light source 33 to pass through the first display panel 31 and the second display panel 32 to reach the observer's viewpoint e0. Therefore, the image display area of ​​the second display panel 32 is larger than the image display area of ​​the first display panel 31 in both the row and column directions, and as shown in Figure 2, the second display panel 32 has an image display area of ​​width W outside the first display panel 31 in both the row and column directions. In the following description, the entire assembly of multiple display panels (in this embodiment, the first display panel 31 and the second display panel 32) may be referred to as a "stacked display panel".

[0017] The image generation unit 20 acquires input image data from an input device (not shown), performs predetermined image processing on the acquired input image data to generate first image data and second image data, and outputs the generated first image data and second image data to the display unit 30. The input device is an information processing device (e.g., a personal computer) and is configured to output various types of data such as image data.

[0018] The first display panel 31 of the display unit 30 displays a first image based on first image data generated by the image generation unit 20, according to control signals or data sent from the image generation unit 20 via a signal cable. The second display panel 32 of the display unit 30 displays a second image based on second image data generated by the image generation unit 20, according to control signals or data sent from the image generation unit 20 via a signal cable. In this embodiment, the first display panel 31 is a color liquid crystal panel and displays a first image which is a color image. The second display panel 32 is a monochrome liquid crystal panel and displays a second image which is a monochrome image.

[0019] The first display panel 31 and the second display panel 32 each display a first image and a second image, respectively, and control the transmittance of the light L emitted from the light source 33, thereby displaying a desired image on the stacked display panel.

[0020] Next, we will describe the image display area of ​​width W that the second display panel 32 has outside the first display panel 31. As shown in Figures 3 and 4, the image display area of ​​width W can be divided into an image display area A1 of width W1 and an image display area A2 of width W2.

[0021] First, the image display area A1 with width W1 will be described with reference to Figure 3. Figure 3 is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e0. As shown in Figure 3, the image display area A1 with width W1 corresponds to the observer's viewpoint range that can be practically assumed to be outside the first display panel 31 of the second display panel 32 when the observer looks at the central part of the stacked display panel. The width W1 can be defined by the distance d1 between the surface of the first display panel 31 and the surface of the second display panel 32 in the normal direction of the stacked display panel (vertical direction in the figure), the distance d2 between the observer's viewpoint e0 and the surface of the first display panel 31 in the normal direction of the stacked display panel, and the angle θ1 between the observer's viewpoint e0 and the edge position of the first display panel 31. The width W0 corresponds to the width of the first display panel 31, that is, the width of the area in which the first display panel 31 and the second display panel 32 overlap.

[0022] Next, the image display area A2 with width W2 will be described with reference to Figure 4. Figure 4 is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e1 (a viewpoint that is outside the ideal viewpoint which is the sweet spot, but is practically conceivable; the same applies hereinafter). As shown in Figure 4, the image display area A2 with width W2 corresponds to the range of the observer's viewpoint that is practically conceivable outside the first display panel 31 of the second display panel 32 when the observer looks at the edge of the stacked display panel. The width W2 is the maximum of the widths that can be defined by the distance d1 between the surface of the first display panel 31 and the surface of the second display panel 32 in the normal direction of the stacked display panel (vertical direction in the figure), the distance d3 between the observer's viewpoint e1 and the surface of the first display panel 31 in the normal direction of the stacked display panel, and the angle θ2 between the observer's viewpoint e1 and the edge position of the first display panel 31.

[0023] Figure 5 shows examples of image display areas A0, A1, and A2 corresponding to widths W0, W1, and W2, respectively, when the second display panel 32 is viewed from the normal direction of the stacked display panel. As shown in Figure 5, the image display area A1 corresponding to width W1 is located outside the image display area A0 corresponding to width W0, and the image display area A2 corresponding to width W2 is located outside the image display area A1.

[0024] In this technology, which aims to improve the contrast of the displayed image by displaying a color image on the first display panel 31, which is the front (observer side) display panel, and a black and white image on the second display panel 32, which is the rear (backlight side) display panel, in order for the first image displayed on the first display panel 31 and the second image displayed on the second display panel 32 to be appropriately superimposed when viewed from the observer's viewpoint e0 (the ideal viewpoint which is the sweet spot) located in front of the display unit 30, it is necessary to enlarge the second image, which is generated with the size of the image display area A0 corresponding to the entire image display area of ​​the first display panel 31, to the size of the sum of the image display area A0 and the image display area A1, and display it. Figure 6 is a diagram showing the concept of enlarging the second image, which is generated with the size of the image display area A0, to the size of the sum of the image display area A0 and the image display area A1, and displaying it.

[0025] Figure 7 is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e0 when, in the second display panel 32, instead of enlarging the second image generated to the size of the image display area A0, the second image generated to the size of the image display area A0 is displayed, and the image display areas A1 and A2 are displayed entirely in black (solid black). In this case, due to the influence of the image display area A1 of the second display panel 32, the edges of the displayed image may not be displayed correctly. For example, the edges of the displayed image may become dark, making it appear as if the edges of the original displayed image are missing (image clipping).

[0026] Figure 8 is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e0 when a second image, generated with the size of image display area A0, is enlarged to the size of the sum of image display area A0 and image display area A1, and image display area A2 is displayed as completely black (solid black). In this case, for example, the edges of the displayed image become brighter, preventing the original edges of the displayed image from appearing to be missing (image clipping), and the problem of the edges of the displayed image not being displayed correctly due to the influence of image display area A1 of the second display panel 32 does not occur.

[0027] However, when the second image is enlarged and displayed, there is a problem in that when an observer looks at the edge of the stacked display panel, the edge of the displayed image (first image) is not displayed correctly due to the influence of the image display area A2 of the second display panel 32 located at the rear. For example, the edge of the displayed image may become dark, making it appear as if the edge of the original displayed image is missing (image clipping). Alternatively, the edge of the displayed image may become bright, making it appear as if the edge of the original displayed image is illuminated (light leakage).

[0028] Figure 9 is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e1 when the observer is looking at the edge of the stacked display panel. As shown in Figure 9, if the right edge of the displayed image (first image) is bright, and the image display area A2 corresponding to the width W2 (right side in the figure) of the second display panel 32 is displayed as completely black (solid black), the edge of the displayed image visible to the observer will become dark, making it appear as if the edge of the original displayed image is missing (image missing).

[0029] Figure 10 is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e2 (a viewpoint that is outside the ideal sweet spot viewpoint but is practically conceivable; the same applies hereafter) when the observer is looking at the edge of the stacked display panel. As shown in Figure 10, if the left edge of the displayed image (first image) in the figure is dark, and the image display area A2 corresponding to the width W2 (left side in the figure) of the second display panel 32 is displayed as entirely white (solid white), the edge of the displayed image visible to the observer will become bright, and the original edge of the displayed image will appear to be illuminated (light leakage).

[0030] Therefore, in this embodiment, the image display device 10 is configured to suppress display abnormalities at the edges of the displayed image, even when the observer looks at the edges of the stacked display panel. The functional configuration of the image display device 10 will now be described, returning to Figure 1.

[0031] As shown in Figure 1, the image generation unit 20 of the image display device 10 includes a linear transformation unit 21, a first image generation unit 22, a first nonlinear transformation unit 23, a second image generation unit 24, a first extension unit 25, a second extension unit 26, and a second nonlinear transformation unit 27. The first image generation unit 22, the second image generation unit 24, the first extension unit 25, and the second extension unit 26 function as the "image generation unit" of the present invention.

[0032] The linear transformation unit 21 performs predetermined processing on the input image data and outputs it to the first image generation unit 22 and the second image generation unit 24. Specifically, the linear transformation unit 21 receives an input signal RGBγ as input image data, in which the grayscale is represented by 10 bits for each of the R, G, and B components. Here, the input signal RGBγ has gamma correction applied to the grayscale of the input image according to the gamma characteristics. The linear transformation unit 21 generates a linear signal RGB that has been transformed so that each component of the input signal RGBγ exhibits a linear characteristic in which the brightness increases linearly with increasing grayscale value. In this embodiment, the conversion to the linear signal RGB is performed using three LUTs (Lookup tables) provided for each component. The linear transformation unit 21 then outputs the generated linear signal RGB to the first image generation unit 22 and the second image generation unit 24.

[0033] As shown in Figure 1, the first image generation unit 22 includes a calculation unit 22A and a coefficient calculation unit 22B. The calculation unit 22A receives a linear signal RGB from the linear transformation unit 21 and a coefficient F from the coefficient calculation unit 22B. The calculation unit 22A then generates a first processed signal RGB' by multiplying the linear signal RGB by the coefficient F and outputs the generated first processed signal RGB' to the first nonlinear transformation unit 23.

[0034] The coefficient calculation unit 22B receives the second processing signal D, described later, from the second image generation unit 24 and outputs a coefficient F associated with the second processing signal D using a LUT. In this embodiment, the light emitted from the light source 33 is transmitted by the second display panel 32 at a transmittance based on the second image data, and further transmitted by the first display panel 31 at a transmittance based on the first image data, thereby achieving a desired transmittance in the stacked display panel according to the input image data. The LUT used by the coefficient calculation unit 22B stores a coefficient F as output data associated with the second processing signal D as input data, based on the transmittance relationship between the first display panel 31 and the second display panel 32.

[0035] The first nonlinear conversion unit 23 receives the first processing signal RGB' output from the first image generation unit 22 (calculation unit 22A) and converts the first processing signal RGB' into a nonlinear signal, the first image signal RGB'γ, using a LUT created for each color component based on the display characteristics of the first display panel 31. The first image signal RGB'γ is output to the display unit 30 as first image data, and the first image based on the first image data is displayed on the first display panel 31.

[0036] As shown in Figure 1, the second image generation unit 24 includes a luminance conversion unit 24A and a smoothing processing unit 24B. The luminance conversion unit 24A receives a linear signal RGB output from the linear conversion unit 21 and performs a luminance conversion process that outputs a luminance V based on the gradation value of each pixel in the input image. In this embodiment, the luminance conversion unit 24A determines the maximum of the gradation values ​​of each color component of each pixel as the luminance and outputs the luminance V, which is a two-dimensional array of the luminances determined for each pixel, to the smoothing processing unit 24B.

[0037] The smoothing processing unit 24B performs a smoothing process on the luminance V output from the luminance conversion unit 24A, for example using an averaging filter, to generate a second processed signal D. The smoothing processing unit 24B then outputs the generated second processed signal D to the first image generation unit 22 (coefficient calculation unit 22B) and the first extension unit 25. Compared to a low-pass filter (LPF) such as a Gaussian filter that applies weights according to distance, the averaging filter results in a constant gradient of gradation in the image after smoothing.

[0038] The first extension unit 25 generates an enlarged image based on the input image data (specifically, an image that has undergone brightness conversion processing and smoothing processing by the second image generation unit 24) for display in the image display areas A0 and A1. The term "image based on input image data" is a concept that includes the image represented by the input image data, and the image after image processing has been applied to the image represented by the input image data.

[0039] In this embodiment, the first extension unit 25 receives a second processing signal D output from the second image generation unit 24 (smoothing processing unit 24B) and performs a predetermined first extension processing. The predetermined first extension processing is the process of generating an image I1 for displaying an image corresponding to the second processing signal D, specifically an image I0 generated with the size of the image display area A0 corresponding to the entire image display area of ​​the first display panel 31, enlarged to the size of the sum of the image display area A0 and the image display area A1. For example, the first extension unit 25 enlarges the image size of the image by a predetermined number of times (converts the image to a number of pixels greater than the original size) by interpolating between pixels of the image generated with the size of the image display area A0 using a general-purpose image interpolation process (e.g., linear interpolation, nearest neighbor interpolation, bilinear interpolation, trilinear interpolation, bicubic interpolation). Then, the first extension unit 25 outputs a second processing signal D' corresponding to the enlarged image I1 to the second extension unit 26.

[0040] The second extension unit 26 receives the second processing signal D' output from the first extension unit 25 and performs a predetermined second extension processing. The predetermined second extension processing is a process to generate an image I2 for display in the image display area A2 by using a boundary pixel area located near the boundary between the image display area A1 (corresponding to the "first display area" of the present invention) and the image display area A2 (corresponding to the "second display area" of the present invention), and generating a second pixel group that includes multiple pixels arranged continuously in a second direction (for example, in the row or column direction) toward the outside of the image display area A2, using a first pixel group that includes multiple pixels arranged continuously in a first direction (for example, in the row or column direction) toward the inside of the image display area A1 as a reference. The second extension unit 26 then generates an image I3 by adding image I2 to the outer periphery of image I1 corresponding to the second processing signal D', and outputs the second processing signal D'' corresponding to the generated image I3 to the second nonlinear transformation unit 27. Furthermore, the vicinity of the boundary between image display area A1 and image display area A2 means, for example, an area that extends from the boundary between image display area A1 and image display area A2 to at least one side of image display area A1 and image display area A2.

[0041] Here, the pattern of change in pixel values ​​(specifically, luminance values) in the second direction for the second pixel group is the same as the pattern of change in pixel values ​​(specifically, luminance values) in the first direction for the first pixel group. Note that the pattern of change in pixel values ​​in the second direction for the second pixel group refers to the change in pixel values ​​along the second direction (including cases where the increase or decrease is not monotonically proportional) when the pixel values ​​of multiple pixels included in the second pixel group change in either the intermediate image (the image obtained during the final image generation process) or the final image (the image that is ultimately displayed and output) (in this embodiment, the final image). Furthermore, the pattern of change in pixel values ​​in the first direction for the first pixel group refers to the change in pixel values ​​along the first direction (including cases where the increase or decrease is not monotonically proportional) when the pixel values ​​of multiple pixels included in the first pixel group change in either the intermediate image (the image obtained during the final image generation process) or the final image (the image that is ultimately displayed and output) (in this embodiment, the final image).

[0042] Figures 11 to 13 illustrate an example of a predetermined second extension process. In the example shown in Figure 11, the boundary pixel region located near the boundary between image display area A1 and image display area A2 consists of one pixel 100 (pixel value, specifically brightness value: 255) located within image display area A1 along a first direction (e.g., row or column direction, to the right in the figure) from the boundary between image display area A1 and image display area A2. In other words, pixel 100 is a single pixel located within image display area A1, adjacent to the boundary between image display area A1 and image display area A2.

[0043] The second extension unit 26 uses a first pixel group, which includes multiple pixels 101,...,102 arranged in a continuous line in a first direction toward the inside of the image display area A1 (for example, row or column direction, to the right in the figure), with respect to the boundary pixel area, to generate a second pixel group, which includes multiple pixels 103,...,104 arranged in a continuous line in a second direction toward the outside of the image display area A2 (for example, row or column direction, to the left in the figure). Here, when the pixel values ​​of the multiple pixels 103,...,104 included in the second pixel group change, the way in which the pixel values ​​increase or decrease along the second direction (in the example of Figure 11, the decrease shown by 192,...,32) is the same as when the pixel values ​​of the multiple pixels 101,...,102 included in the first pixel group change, the way in which the pixel values ​​increase or decrease along the first direction (in the example of Figure 11, the decrease shown by 192,...,32) is the same. Specifically, the second extension unit 26 generates the second pixel group using the first pixel group such that the order of pixel values ​​in the second direction (192,...,32) of the multiple pixels 103,...,104 included in the second pixel group is the same as (including cases where they are not exactly the same as) the order of pixel values ​​in the first direction (192,...,32) of the multiple pixels 101,...,102 included in the first pixel group.

[0044] In the example shown in Figure 12, the boundary pixel region located near the boundary between image display area A1 and image display area A2 consists of one pixel 100 (pixel value, specifically brightness value: 255) located within image display area A1 along a first direction (e.g., row or column direction, to the right in the figure) from the boundary between image display area A1 and image display area A2, and one pixel 105 (pixel value, specifically brightness value: 255) having the same pixel value as pixel 100 and located within image display area A2 along a second direction (e.g., row or column direction, to the left in the figure) from the boundary. In other words, pixel 100 is a pixel located within image display area A1, adjacent to the boundary between image display area A1 and image display area A2, and pixel 105 is a pixel located within image display area A2, adjacent to the boundary between image display area A1 and image display area A2.

[0045] The second extension unit 26 uses a first pixel group, which includes multiple pixels 101,...,102 arranged in a continuous line in a first direction toward the inside of the image display area A1 (for example, row or column direction, to the right in the figure), with respect to the boundary pixel area, to generate a second pixel group, which includes multiple pixels 106,...,107 arranged in a continuous line in a second direction toward the outside of the image display area A2 (for example, row or column direction, to the left in the figure). Here, when the pixel values ​​of the multiple pixels 106,...,107 included in the second pixel group change, the way in which the pixel values ​​increase or decrease along the second direction (in the example of Figure 12, the decrease shown by 192,...,32) is the same as when the pixel values ​​of the multiple pixels 101,...,102 included in the first pixel group change, the way in which the pixel values ​​increase or decrease along the first direction (in the example of Figure 12, the decrease shown by 192,...,32) is the same. Specifically, the second extension unit 26 generates the second pixel group using the first pixel group such that the order of pixel values ​​in the second direction (192,...,32) of the multiple pixels 106,...,107 included in the second pixel group is the same as (including cases where they are not exactly the same as) the order of pixel values ​​in the first direction (192,...,32) of the multiple pixels 101,...,102 included in the first pixel group.

[0046] In the example shown in Figure 13, the boundary pixel region located near the boundary between image display area A1 and image display area A2 consists of one pixel 100 (pixel value, specifically brightness value: 255) located along a first direction (e.g., row or column direction, to the right in the figure) within image display area A1 from the boundary between image display area A1 and image display area A2, and a plurality of pixels 108, ..., 109 (pixel value, specifically brightness value: 255) that have the same pixel value as pixel 100 and are located along a second direction (e.g., row or column direction, to the left in the figure) within image display area A2 from the boundary, i.e., arranged in a continuous line.

[0047] The second extension unit 26 uses a first pixel group, which includes multiple pixels 101,...,102 arranged in a continuous line in a first direction toward the inside of the image display area A1 (for example, row or column direction, to the right in the figure), with respect to the boundary pixel area, to generate a second pixel group, which includes multiple pixels 110,...,111 arranged in a continuous line in a second direction toward the outside of the image display area A2 (for example, row or column direction, to the left in the figure). Here, when the pixel values ​​of the multiple pixels 110,...,111 included in the second pixel group change, the way in which the pixel values ​​increase or decrease along the second direction (in the example of Figure 13, the decrease shown by 192,...,32) is the same as when the pixel values ​​of the multiple pixels 101,...,102 included in the first pixel group change, the way in which the pixel values ​​increase or decrease along the first direction (in the example of Figure 13, the decrease shown by 192,...,32) is the same. Specifically, the second extension unit 26 generates the second pixel group using the first pixel group such that the order of pixel values ​​in the second direction (192,...,32) of the multiple pixels 110,...,111 included in the second pixel group is the same as (including cases where they are not exactly the same as) the order of pixel values ​​in the first direction (192,...,32) of the multiple pixels 101,...,102 included in the first pixel group.

[0048] Figure 14A is a diagram showing an example of an image that shows the edge of the image display area A1 after a predetermined first expansion process has been performed by the first expansion unit 25. As shown in Figure 14A, a semicircular white image exists at the edge of the image display area A1.

[0049] Figure 14B is a diagram showing an example of an image showing the edge of image display area A1 and image display area A2 after a predetermined second expansion process has been performed by the second expansion unit 26 using the image shown in Figure 14A. In other words, the second expansion unit 26 uses a first pixel group, which includes multiple pixels arranged continuously in a first direction toward the inside of image display area A1 (for example, row or column direction, to the right in the figure), with respect to the boundary pixel area, to generate a second pixel group, which includes multiple pixels arranged continuously in a second direction toward the outside of image display area A2 (for example, row or column direction, to the left in the figure). Here, when the pixel values ​​of multiple pixels included in the second pixel group change, the way in which the pixel values ​​increase or decrease (in the example of Figure 14B, decrease) along the second direction is the same as the way in which the pixel values ​​of multiple pixels included in the first pixel group change along the first direction.

[0050] Figure 14C is a comparative example with Figure 14B, showing an example of an image showing the edge of image display area A1 and image display area A2 after a process different from the predetermined second expansion process performed by the second expansion unit 26, using the image shown in Figure 14A. The process different from the predetermined second expansion process is a process of continuously copying pixels included in the boundary pixel area within image display area A1 in a second direction toward the outside of image display area A2 (for example, row or column direction, left direction in the figure). In other words, unlike the example image shown in Figure 14B, the pixel values ​​of multiple pixels included in the second pixel group in image display area A2 along the second direction do not change, and the display manner is completely different from the change in pixel values ​​(specifically, decrease) along the first direction (for example, row or column direction, right direction in the figure) of multiple pixels included in the first pixel group in image display area A1.

[0051] Figure 15A is a diagram showing an example of an image that shows the edge of the image display area A1 after a predetermined first expansion process has been performed by the first expansion unit 25. As shown in Figure 15A, at the edge of the image display area A1, there is a white image that extends in the vertical direction in the figure and protrudes to the right in the figure at the center of the vertical direction in the figure.

[0052] Figure 15B is a diagram showing an example of an image showing the edge of image display area A1 and image display area A2 after a predetermined second expansion process has been performed by the second expansion unit 26 using the image shown in Figure 15A. In other words, the second expansion unit 26 uses a first pixel group, which includes multiple pixels that are continuously arranged in a first direction toward the inside of image display area A1 (for example, row or column direction, to the right in the figure), with respect to the boundary pixel area, to generate a second pixel group, which includes multiple pixels that are continuously arranged in a second direction toward the outside of image display area A2 (for example, row or column direction, to the left in the figure). Here, when the pixel values ​​of multiple pixels included in the second pixel group change, the way in which the pixel values ​​increase or decrease (in the example of Figure 15B, decrease) along the second direction is the same as the way in which the pixel values ​​of multiple pixels included in the first pixel group change along the first direction.

[0053] Figure 15C is a comparative example with Figure 15B, showing an example of an image showing the edge of image display area A1 and image display area A2 after a process different from the predetermined second expansion process performed by the second expansion unit 26, using the image shown in Figure 15A. The process different from the predetermined second expansion process is a process of continuously copying pixels included in the boundary pixel area within image display area A1 in a second direction toward the outside of image display area A2 (for example, row or column direction, left direction in the figure). In other words, unlike the example image shown in Figure 15B, the pixel values ​​of multiple pixels included in the second pixel group in image display area A2 along the second direction do not change, and the display manner is completely different from the change in pixel values ​​(specifically, decrease) along the first direction (for example, row or column direction, right direction in the figure) of multiple pixels included in the first pixel group in image display area A1.

[0054] Figure 16 is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e1 when the observer looks at the edge of the stacked display panel after a predetermined second expansion process has been performed by the second expansion unit 26. As shown in Figure 16, the right edge of the displayed image (first image) in the figure is bright, and the image display area A2 corresponding to the width W2 (right side in the figure) of the second display panel 32 is also displayed brightly, for example, as solid white. This suppresses the problem of the edge of the displayed image appearing to be missing (image clipping) due to the edge of the displayed image visible to the observer becoming darker.

[0055] Figure 17 is a schematic diagram showing the positional relationship between the display unit 30 of the image display device 10 and the observer's viewpoint e2 when a predetermined second expansion process is performed by the second expansion unit 26 and the observer looks at the edge of the stacked display panel. As shown in Figure 17, the left edge of the displayed image (first image) in the figure is darkened, and the image display area A2 corresponding to the width W2 (left side in the figure) of the second display panel 32 is also displayed darkened. As a result, the edge of the displayed image visible to the observer becomes brighter, and the problem of the original edge of the displayed image appearing to be lit (light leakage) is suppressed.

[0056] Based on the above, the image display device 10 of this embodiment can suppress display abnormalities at the edges of the displayed image (for example, image loss or light leakage) even when the observer looks at the edges of the stacked display panel.

[0057] The second nonlinear conversion unit 27 receives the second processing signal D'' output from the second extension unit 26 and converts the second processing signal D'' into a nonlinear signal, the second processing signal D''γ, using a LUT created for each color component based on the display characteristics of the second display panel 32. The second processing signal D''γ is output to the display unit 30 as second image data, and a second image based on the second image data is displayed on the second display panel 32.

[0058] Figure 18 is a flowchart showing an example of the image display processing (corresponding to the "image display method" of the present invention) performed by the image display device 10 in this embodiment.

[0059] First, in step S100, the linear transformation unit 21 generates a linear signal RGB by transforming each component of the input signal RGBγ (where the grayscale is represented by 10 bits for each of the R, G, and B components) received as input image data, so that the brightness increases linearly with increasing grayscale value. Then, the linear transformation unit 21 outputs the generated linear signal RGB to the first image generation unit 22 and the second image generation unit 24. Once the processing in step S100 is completed, the processing in steps S110 and S130 begins.

[0060] In step S110, the first image generation unit 22 performs a predetermined first image generation process. Specifically, the calculation unit 22A of the first image generation unit 22 receives a linear signal RGB from the linear transformation unit 21 and a coefficient F from the coefficient calculation unit 22B. The calculation unit 22A then generates a first processed signal RGB' by multiplying the linear signal RGB by the coefficient F and outputs the generated first processed signal RGB' to the first nonlinear transformation unit 23. The coefficient calculation unit 22B receives the second processed signal D output from the second image generation unit 24 in step S130 and outputs a coefficient F, which is associated with the second processed signal D using a LUT, to the calculation unit 22A. Once the processing in step S110 is completed, the processing in step S120 begins.

[0061] In step S120, the first nonlinear conversion unit 23 receives the first processing signal RGB' output from the first image generation unit 22 (calculation unit 22A) and performs a first nonlinear conversion process to convert the first processing signal RGB' into a nonlinear signal, the first image signal RGB'γ, using a LUT created for each color component based on the display characteristics of the first display panel 31. The first image signal RGB'γ is then output to the display unit 30 as first image data, and the first image based on the first image data is displayed on the first display panel 31.

[0062] In step S130, the luminance conversion unit 24A of the second image generation unit 24 receives the linear signal RGB output from the linear conversion unit 21 and outputs the luminance V to the smoothing processing unit 24B based on the grayscale value of each pixel in the input image. Subsequently, the smoothing processing unit 24B of the second image generation unit 24 performs a smoothing process on the luminance V output from the luminance conversion unit 24A, for example using an averaging filter, to generate a second processed signal D. The smoothing processing unit 24B then outputs the generated second processed signal D to the first image generation unit 22 (coefficient calculation unit 22B) and the first extension unit 25. Upon completion of the processing in step S130, the processing in step S140 begins.

[0063] In step S140, the first expansion unit 25 receives the second processing signal D output from the second image generation unit 24 (smoothing processing unit 24B) and performs a predetermined first expansion process. The predetermined first expansion process is the process of generating an image I1 for displaying an image corresponding to the second processing signal D, specifically an image I0 generated with the size of the image display area A0 corresponding to the entire image display area of ​​the first display panel 31, enlarged to the size of the sum of the image display area A0 and the image display area A1. The first expansion unit 25 then outputs the second processing signal D' corresponding to the enlarged image I1 to the second expansion unit 26. Upon completion of the process in step S140, the process in step S150 begins.

[0064] In step S150, the second extension unit 26 receives the second processing signal D' output from the first extension unit 25 and performs a predetermined second extension processing. The predetermined second extension processing is a process to generate an image I2 for display in image display area A2 by using a first group of pixels, which includes multiple pixels arranged continuously in a first direction toward the inside of image display area A1 (for example, row or column direction), as a reference to a boundary pixel area located near the boundary between image display area A1 and image display area A2, and generating a second group of pixels, which includes multiple pixels arranged continuously in a second direction toward the outside of image display area A2 (for example, row or column direction). The second extension unit 26 then generates an image I3 by adding image I2 to the outer periphery of image I1 corresponding to the second processing signal D', and outputs the second processing signal D'' corresponding to the generated image I3 to the second nonlinear transformation unit 27. Upon completion of the processing in step S150, the processing in step S160 begins.

[0065] In step S160, the second nonlinear conversion unit 27 receives the second processing signal D'' output from the second extension unit 26 and performs a second nonlinear conversion process to convert the second processing signal D'' into a nonlinear signal, the second processing signal D''γ, using a LUT created based on the display characteristics of the second display panel 32. The second processing signal D''γ is output to the display unit 30 as second image data, and a second image based on the second image data is displayed on the second display panel 32. Upon completion of the processes in steps S120 and S160, the image display device 10 terminates the image display process shown in Figure 18.

[0066] As described in detail above, in this embodiment, the image display device 10 is arranged with a plurality of display panels superimposed on each other, and an image is displayed on each display panel. The image display device 10 includes a first display panel 31 positioned closer to the observer, a second display panel 32 positioned further from the observer than the first display panel 31, and an image generation unit (first image generation unit 22, second image generation unit 24, first extension unit 25, second extension unit 26) that generates first image data for displaying a first image in the image display area of ​​the first display panel 31 and second image data for displaying a second image in the image display area of ​​the second display panel 32 based on input image data. The image display area of ​​the second display panel 32 is larger than the image display area of ​​the first display panel 31. The image display area of ​​the second display panel 32 includes display areas A0, A1 (first display areas) and an image display area A2 (second display area) located outside of display areas A0, A1 (first display areas). The image generation unit (second extension unit 26) uses a boundary pixel region located near the boundary between image display area A1 and image display area A2 as a reference, and generates a second pixel group containing multiple pixels that are continuously arranged in a second direction (for example, row or column direction) toward the outside of image display area A2, using a first pixel group containing multiple pixels that are continuously arranged in a first direction toward the inside of image display area A1 (for example, row or column direction). The manner in which the pixel values ​​change in the second direction for the second pixel group is the same as the manner in which the pixel values ​​change in the first direction for the first pixel group.

[0067] According to this embodiment, in the second display panel 32, which is positioned further from the observer than the first display panel 31, the second pixel group is generated using the first pixel group, with reference to the boundary pixel area located near the boundary between image display area A1 and image display area A2, such that the pattern of change in pixel values ​​in the second direction for the second pixel group is the same as the pattern of change in pixel values ​​in the first direction for the first pixel group. This suppresses display abnormalities (image loss, light leakage) at the edges of the displayed image when an observer views the edges of the display screen of the image display device 10 from an oblique direction. Furthermore, the process of generating the second pixel group that points outwards from image display area A2 using the first pixel group that points inwards from image display area A1 is a relatively simple process, thus enabling the suppression of display abnormalities at the edges of the displayed image at a low cost.

[0068] Furthermore, if the input image corresponding to the input image data input to the image display device 10 is, for example, an image of a starry sky, and stars (bright spots) exist at the edges of the image, then if the edges of the image are stretched as in the generation method described with reference to Figures 14C and 15C, the high-brightness region will spread outwards, which may cause display abnormalities such as light leakage being perceived by the observer at the edges of the image, or the bright spots at the edges appearing relatively brighter when bright spots of the same brightness exist at both the edges and other parts of the image. However, if the second pixel group is generated using the first pixel group as in this embodiment, the edges of the image will not be simply stretched, thus suppressing the occurrence of the above-mentioned display abnormalities.

[0069] In the above embodiment, the first expansion unit 25 may also enlarge an image based on input image data (specifically, an image that has undergone brightness conversion processing and smoothing processing by the second image generation unit 24) by less than 1 pixel (for example, 0.2 pixels) to generate an image for display in image display areas A0 and A1.

[0070] Furthermore, in the above embodiment, the first extension unit 25 may generate images for display in the image display areas A0 and A1 without enlarging the image based on the input image data.

[0071] Furthermore, in the above embodiment, the first expansion process by the first expansion unit 25 and the second expansion process by the second expansion unit 26 may be executed simultaneously, or the first expansion process by the first expansion unit 25 may be executed after the second expansion process by the second expansion unit 26. Also, the second expansion process by the second expansion unit 26 may be executed immediately before or after the linear transformation process by the linear transformation unit 21, or immediately before or after the smoothing process by the smoothing processing unit 24B. Note that if the image display area A1 can be considered minute, the execution of the first expansion process by the first expansion unit 25 may be omitted, or the image display area A1 may be set within the image display area A0 as necessary.

[0072] Figure 19 illustrates the interpolation process (for example, linear interpolation) performed in the first extension process when the first extension process is performed by the first extension unit 25 after the second extension process is performed by the second extension unit 26.

[0073] First, the second extension unit 26 uses a boundary pixel region, which is a single pixel 120 (pixel value, specifically brightness value: 255), as a reference, and generates a second pixel group, which includes a plurality of pixels 123, 124, ... arranged in a second direction toward the outside of the image display area A0 (for example, row or column direction, left direction in the figure), using a first pixel group that includes a plurality of pixels 121, 122, ... arranged in a first direction toward the inside of the image display area A0 (for example, row or column direction, left direction in the figure). Here, when the pixel values ​​of multiple pixels 123, 124, ... included in the second pixel group change, the increase or decrease in pixel values ​​along the second direction (in the example shown in Figure 19, the decrease shown by 192, 32, ...) is the same as the increase or decrease in pixel values ​​along the first direction (in the example shown in Figure 19, the decrease shown by 192, 32, ...) when the pixel values ​​of multiple pixels 121, 122, ... included in the first pixel group change.

[0074] Next, the first expansion unit 25 generates an image in which an image having a group of pixels including multiple pixels 120, 121, 122, 123, and 124 is enlarged by less than one pixel (for example, 0.2 pixels). In Figure 19, the pixel value of pixel 125 after image enlargement is calculated to be 96 by linear interpolation (192 × 0.4 + 32 × 0.6) using the pixel values ​​of pixels 121 and 122 before image enlargement. Here, 0.4 and 0.6 are determined as weighting coefficients from the ratio of the degree of overlap between the positions of pixel 125 and pixels 121 and 122 in the left-right direction (for example, row or column direction) in the figure. Similarly, the pixel value of pixel 126 after image enlargement is calculated to be 217 by linear interpolation (255 × 0.4 + 192 × 0.6) using the pixel values ​​of pixels 120 and 121 before image enlargement. Furthermore, the pixel value of pixel 127 after image enlargement is calculated as 230 by linear interpolation (192 × 0.4 + 255 × 0.6) using the pixel values ​​of pixels 123 and 120 before image enlargement. Similarly, the pixel value of pixel 128 after image enlargement is calculated as 128 by linear interpolation (32 × 0.4 + 192 × 0.6) using the pixel values ​​of pixels 124 and 123 before image enlargement. Furthermore, before the interpolation process is performed in the first extension process, the pattern of change in the pixel values ​​of multiple pixels along the first direction (for example, alternating between decreasing and increasing) and the pattern of change in the pixel values ​​of multiple pixels along the second direction (for example, alternating between decreasing and increasing) are the same; that is, the relationship of increase and decrease between pixels along the first direction and the relationship of increase and decrease between pixels along the second direction are exactly the same. On the other hand, depending on the pixel values ​​of multiple pixels included in the first pixel group, after the interpolation process is performed in the first extension process, the pattern of change in the pixel values ​​of multiple pixels along the first direction (for example, alternating between increasing and decreasing) and the pattern of change in the pixel values ​​of multiple pixels along the second direction (for example, not alternating between increasing and decreasing) are substantially the same; that is, the tendency of how the observer perceives the pattern of change in pixel values ​​in the first direction and the pattern of change in pixel values ​​in the second direction will be the same, but there may be cases where the relationship of increase and decrease between pixels along the first direction and the relationship of increase and decrease between pixels along the second direction are strictly different in some respects.In such cases, after interpolation processing is performed in the first extension process, the tendency of how the pixel values ​​change in the first direction and the pixel values ​​change in the second direction are the same in terms of how the observer perceives them, and therefore this falls under the "the mode of change of pixel values ​​in the second direction is the same as the mode of change of pixel values ​​in the first direction" provision of the present invention.

[0075] Furthermore, in the above embodiment, an example was described in which the image display device 10 comprises a first display panel 31 and a second display panel 32 having a larger image display area than the first display panel 31, but the present invention is not limited to this. For example, the image display device 10 may comprise a first display panel 31 and a second display panel 32 having the same image display area as the first display panel 31. In this case, the edge area of ​​the first display panel 31 may be set as a non-image display area, and the image display area of ​​the second display panel 32 may be made larger than the image display area of ​​the first display panel 31. Alternatively, by displaying a first image on the first display panel 31 in a reduced size, the second image displayed on the second display panel 32 may be made larger than the first image displayed on the first display panel 31, and consequently, the image display area of ​​the second display panel 32 may be made larger than the image display area of ​​the first display panel 31.

[0076] Furthermore, although the above embodiment describes an example in which the image display area of ​​the second display panel 32 is larger than the image display area of ​​the first display panel 31 in both the row and column directions, the present invention is not limited to this. For example, the image display area of ​​the second display panel 32 may be larger than the image display area of ​​the first display panel 31 in either the row or column direction.

[0077] Furthermore, in the above embodiment, an example was described in which the first direction toward the inside of the image display area A1 is, for example, the row or column direction, and the second direction toward the outside of the image display area A2 is, for example, the row or column direction. However, the present invention is not limited to this. For example, at the corner portion of the image display area A1, the first direction toward the inside of the image display area A1 may be the direction in which the row or column direction is rotated 45 degrees clockwise. In this case, at the corner portion of the image display area A2 adjacent to the corner portion of the image display area A1, the second direction toward the outside of the image display area A2 may be the direction in which the row or column direction is rotated 45 degrees clockwise.

[0078] Furthermore, although the above embodiment describes an example in which the image display device 10 is a color liquid crystal display device using three RGB colors, the present invention is not limited to this. For example, the image display device 10 may be a monochrome liquid crystal display device in which both the first display panel 31 and the second display panel 32 are composed of monochrome liquid crystal panels. Also, the image display device 10 may be a liquid crystal display device in which the number of pixels differs between the first display panel 31 and the second display panel 32. In addition, the image display device 10 may be a liquid crystal display device that uses local dimming technology to control the light source 33 (backlight) for each section so that the resolution of the second display panel 32 can be set lower than that of the first display panel 31.

[0079] Furthermore, in the above embodiment, the position of the first display panel 31 may be shifted relative to the second display panel 32 so that when an observer views the edge of the display screen of the image display device 10 from an oblique direction, the first image displayed on the first display panel 31 and the second image displayed on the second display panel 32 overlap. Alternatively, the display position of the first image displayed on the first display panel 31 may be shifted relative to the second image displayed on the second display panel 32 so that when an observer views the edge of the display screen of the image display device 10 from an oblique direction, the first image displayed on the first display panel 31 and the second image displayed on the second display panel 32 overlap.

[0080] Although various embodiments of the present invention have been described above, these are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0081] 10: Image display device, 20: Image generation unit, 21: Linear transformation unit, 22: First image generation unit, 22A: Calculation unit, 22B: Coefficient calculation unit, 23: First nonlinear transformation unit, 24: Second image generation unit, 24A: Brightness transformation unit, 24B: Smoothing processing unit, 25: First extension unit, 26: Second extension unit, 30: Display unit, 31: First display panel, 32: Second display panel, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 120, 121, 122, 123, 124, 125, 126, 127, 128: Pixels

Claims

1. An image display device in which multiple display panels are arranged in an overlapping manner, and an image is displayed on each of the display panels, A first display panel positioned close to the observer, A second display panel is positioned further from the observer than the first display panel, An image generation unit generates first image data for displaying a first image in the image display area of ​​the first display panel and second image data for displaying a second image in the image display area of ​​the second display panel, based on input image data. Equipped with, The image generation unit generates the first image data and the second image data in such a way that the contrast of the image displayed is improved when the first image displayed on the first display panel and the second image displayed on the second display panel are superimposed. The image display area of ​​the second display panel is larger than the image display area of ​​the first display panel. The image display area of ​​the second display panel includes an area that overlaps with the image display area of ​​the first display panel when viewed from the normal direction of the plurality of display panels, a first display area located outside said area, and a second display area located outside said first display area. The image generation unit uses a boundary pixel region located near the boundary between the first and second display regions as a reference, and generates a second pixel group that includes a plurality of pixels arranged continuously in a second direction toward the outside of the second display region, using a first pixel group that includes a plurality of pixels arranged continuously in a first direction toward the inside of the first display region as a reference. The pattern of change in pixel values ​​in the second direction for the second pixel group is the same as the pattern of change in pixel values ​​in the first direction for the first pixel group. Image display device.

2. An image display device according to claim 1, The image generation unit generates an image which is an enlarged image based on the input image data, and generates an image for display in the first display area. Image display device.

3. An image display device according to claim 2, The image to be displayed in the first display area is an image obtained by enlarging the image based on the input image data with an accuracy of less than one pixel. Image display device.

4. An image display device according to any one of claims 1 to 3, The boundary pixel region consists of one or more pixels located along the first direction within the first display region, from the boundary between the first and second display regions. Image display device.

5. An image display device according to any one of claims 1 to 3, The boundary pixel region comprises one or more pixels located along the first direction within the first display region from the boundary between the first and second display regions, and one or more pixels located along the second direction within the second display region from the boundary between the first and second display regions. Image display device.

6. An image display method that displays an image on each of multiple display panels arranged in an overlapping manner, The process includes an image generation step of generating, based on input image data, first image data for displaying a first image in the image display area of ​​a first display panel located closer to the observer, and second image data for displaying a second image in the image display area of ​​a second display panel located further from the observer than the first display panel. In the image generation step, the first image data and the second image data are generated in such a way that the contrast of the displayed image is improved when the first image displayed on the first display panel and the second image displayed on the second display panel are superimposed. The image display area of ​​the second display panel is larger than the image display area of ​​the first display panel. The image display area of ​​the second display panel includes an area that overlaps with the image display area of ​​the first display panel when viewed from the normal direction of the plurality of display panels, a first display area located outside said area, and a second display area located outside said first display area. In the image generation step, a boundary pixel region located near the boundary between the first and second display regions is used as a reference, and a second pixel group is generated using a first pixel group that includes a plurality of pixels arranged continuously in a first direction toward the inside of the first display region, and a plurality of pixels arranged continuously in a second direction toward the outside of the second display region. The pattern of change in pixel values ​​in the second direction for the second pixel group is the same as the pattern of change in pixel values ​​in the first direction for the first pixel group. Image display method.

7. An image display program that causes a processor to execute the image display method described in claim 6.

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