JP5367182B2 - Image display device - Google Patents

Abstract

The present invention provides an image processing device with which it is possible to make crosstalk difficult to visually recognize even when crosstalk arises under differing circumstances by image display direction. An image processing device (190) comprises: a crosstalk compensation unit (191) which receives an image signal (G) which denotes a gradation value of each sub-pixel in an image that is formed by compositing a first and second image which are displayed in respectively different directions, wherein a plurality of pixels, each including one or more sub-pixels, are arrayed, and the sub-pixels configuring the first image and the sub-pixels configuring the second image are alternately arrayed. The crosstalk compensation unit (191) compensates for the gradation value of the sub-pixels of the image signal such that crosstalk between the first and second images is difficult to visually recognize. The crosstalk compensation unit (191) changes the degree of compensation for the gradation value of the sub-pixels by the direction in which the sub-pixels are displayed.

Description

  The present invention relates to an image processing device and an image display device.

  A technique has been developed that enables a liquid crystal display device and a parallax barrier that is a light shielding barrier or a parallax optical element such as a lenticular screen to recognize different images depending on the viewing direction on the same display screen ( (See Patent Document 1 and Patent Document 2). By using this technology, the navigation image on the driver's seat side and the television image etc. on the passenger seat side can be displayed at the same time, and images with parallax can be displayed on the left and right without using special glasses. An autostereoscopic display to be presented to each eye has been put into practical use.

  The display device as described above has a problem in that so-called crosstalk occurs in which an image to be presented in one direction is superimposed on an image to be presented in another direction and viewed as a double image. .

  There are various causes of the occurrence of crosstalk. One of the crosstalks is electrical crosstalk that is generated when an electrical signal for a certain subpixel electrically affects adjacent subpixels. For example, in a liquid crystal display device in which a plurality of source lines (signal lines) and a plurality of gate lines (scanning lines) are arranged in a matrix and subpixels are provided corresponding to the intersections of the source lines and the gate lines, There is an electrical crosstalk due to the influence of capacitive coupling due to parasitic capacitance between the source lines of the pixels, which is large when the gradation difference between adjacent sub-pixels is large. As a solution to this problem, Patent Document 3 includes a lookup table (LUT) corresponding to the signal level of the correction target sub-pixel and the signal level of the adjacent sub-pixel. A method of correcting based on the signal level is disclosed.

  In the case of a directional image or a stereoscopic image display device that displays a plurality of images in different directions on the same display screen, crosstalk caused by a structure that is not found in a normal liquid crystal display device such as a parallax barrier or a lenticular screen is also conceivable . For example, there is optical crosstalk in which image light to be presented in one direction leaks in another direction. This optical crosstalk occurs, for example, when the light emission of the sub-pixel is not completely shielded by the parallax barrier.

  With the method described in Patent Document 3, it is not possible to correct optical crosstalk due to such a structure that is not found in a normal liquid crystal display device.

  As a technique for correcting optical crosstalk, Patent Document 4 discloses a technique that corrects the gradation of a subpixel to be corrected based on the gradation of a subpixel of the same color of an adjacent pixel.

Japanese Patent No. 4530267 Japanese Patent No. 4367775 JP 2006-23710 A Japanese Patent No. 4375468

  By the way, in an image display apparatus that displays a plurality of images in different directions on the same display screen, the occurrence of crosstalk may differ depending on the image display direction.

  An object of the present invention is to provide an image processing apparatus and an image display apparatus that can make it difficult to visually recognize crosstalk even when the occurrence of crosstalk varies depending on the image display direction.

The image display device of the present invention is an image obtained by combining a first image displayed in a first direction and a second image displayed in a second direction different from the first direction, An image in which a plurality of pixels including two or more sub-pixels corresponding to each of the colors are arranged, and sub-pixels constituting the first image and sub-pixels constituting the second image are alternately arranged The image signal representing the gradation value of each of the sub-pixels is received as an input image signal, and the input image signal is made less visible by correcting the influence of crosstalk between the first image and the second image. A crosstalk correction unit that corrects a gradation value of the sub-pixel and outputs an image signal after crosstalk correction; and based on the image signal after the crosstalk correction, the first image is moved in the first direction. Display the second image A display unit having a display surface for displaying the serial second direction
An angle formed between the first direction and the front direction of the display surface is smaller than an angle formed between the second direction and the front direction of the display surface, and the crosstalk correction unit includes: A sub-pixel selection unit and a correction unit, wherein the sub-pixel selection unit includes the correction target sub-pixel when the display direction of the correction target sub-pixel is the first direction. A plurality of pixels that are adjacent to each other is defined as an adjacent pixel group, among subpixels included in the adjacent pixel group, the subpixels that are displayed in the second direction and that have the same color as the correction target subpixel. When a gradation value is selected and the direction in which the correction target sub-pixel is displayed is the second direction, a plurality of pixels surrounding the adjacent pixel group are defined as surrounding pixel groups. And among the sub-pixels included in the surrounding pixel group, The grayscale value of the subpixel displayed in the first direction and having the same color as the subpixel to be corrected is selected, and the correction target is selected from the grayscale values of the subpixels selected by the subpixel selection unit. An average value or a weighted addition value of gradation values of sub-pixels in a direction close to the sub-pixel is calculated as an added gradation value, and the correction unit calculates the corrected gradation value as the correction value. A gradation value that cancels a deviation in gradation value due to the influence of crosstalk on the target subpixel is set as a correction value corresponding to the gradation value of each of the subpixels, and the correction target subpixel is used using the correction value. The tone value is corrected .

  According to the present invention, it is possible to make it difficult to visually recognize the crosstalk even when the occurrence state of the crosstalk varies depending on the display direction of the image.

1 is a block diagram illustrating a configuration of an image display device according to a first embodiment. It is a schematic plan view which shows an example of a structure of a display part. It is a figure which shows an example of the sub pixel arrangement | sequence of the image signal input. It is a figure which shows the optical crosstalk by diffraction of light. It is a figure which shows the optical crosstalk by reflection of light. FIG. 4 is a diagram illustrating a sub-pixel array in which a part of the image signal in FIG. 3 is cut out. It is a figure which shows the adjacent pixel with respect to the center pixel of FIG. It is a figure which shows the surrounding pixel with respect to the center pixel of FIG. FIG. 7 is a diagram illustrating a sub-pixel that affects optical crosstalk with respect to the central sub-pixel in FIG. 6. It is a figure which shows an example of LUT used by a crosstalk correction | amendment part. It is a block diagram which shows an example of a structure of a crosstalk correction | amendment part. 3 is a flowchart illustrating an operation of the image display device according to the first embodiment. (A) And (b) is a figure which shows the input image, (c), (d), and (e) are figures which show the image visually recognized when seeing the screen of a display part from right direction. It is. 6 is a block diagram illustrating a configuration of a crosstalk correction unit included in an image display device according to Embodiment 2. FIG. FIG. 6 is a block diagram illustrating a configuration of an image display device according to a third embodiment. 10 is a block diagram illustrating an example of a configuration of a crosstalk correction unit according to Embodiment 3. FIG. FIG. 10 is a block diagram illustrating a configuration of an image display device according to a fourth embodiment. FIG. 10 is a block diagram illustrating an example of a configuration of a crosstalk correction unit according to a fourth embodiment. FIG. 10 is a block diagram illustrating a configuration of an image display device according to a fifth embodiment. FIG. 10 is a diagram illustrating an example of a usage pattern of an image display device according to a fifth embodiment. FIG. 10 is a schematic plan view illustrating an example of a structure of a display unit according to a fifth embodiment. (A) And (b) is a figure which shows the luminance distribution of a display part. It is a figure which shows the measuring method of the luminance distribution of a display part. FIG. 10 is a block diagram illustrating an example of a configuration of a crosstalk correction unit according to a fifth embodiment. 10 is a flowchart illustrating a crosstalk correction process of the image display device according to the fifth embodiment. 14 is a flowchart illustrating processing of a sub-pixel selection unit according to the fifth embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
In this embodiment, an apparatus or a method that makes it difficult to visually recognize optical crosstalk caused by adjacent pixels and surrounding pixels will be described.
FIG. 1 is a block diagram schematically showing a configuration of an image display apparatus 100 according to the first embodiment of the present invention. The image display device 100 is a device that displays a plurality of images in different directions on the same display screen. For example, the image display device 100 is an image display device capable of displaying a direction-specific image or a stereoscopic image. That is, the image display device 100 is, for example, a direction-specific image display device that presents different images to viewers in a plurality of directions, or a stereoscopic image display device that presents images with parallax to the left and right eyes, respectively.

  In FIG. 1, the image display apparatus 100 includes an input terminal 1, a crosstalk correction unit 2, a gradation conversion unit 3, a timing signal generation unit 4, and a display unit 5.

  The input terminal 1 receives an input of the image signal G. The image signal G is a signal representing the gradation value of each sub-pixel of an image obtained by combining different first and second images. Here, the image signal G is a digital signal composed of a gradation value of each sub-pixel and a synchronization signal. The image signal G is, for example, a signal output by a head unit device including a car navigation function and a DVD playback function by combining a car navigation image and a DVD playback image.

  The crosstalk correction unit 2 corrects the gradation value of the sub-pixel of the image signal G input to the input terminal 1. Specifically, the crosstalk correction unit 2 performs a correction on the image signal G so as to cancel the change in the gradation level due to the crosstalk. The crosstalk correction unit 2 may perform correction smaller than a change in one gradation that can be expressed by the display unit 5.

  The gradation conversion unit 3 performs gradation conversion processing on the image signal after the crosstalk correction so that the display unit 5 can visually recognize a correction smaller than one gradation of the display unit 5 by the crosstalk correction unit 2. That is, the gradation conversion unit 3 converts the number of gradations of the image signal after crosstalk correction so as to match the number of gradations of the display unit 5. Examples of tone conversion processing include dither processing and error diffusion processing.

  The timing signal generation unit 4 generates a signal for displaying an image signal on the display unit 5 such as a start pulse, an effective period signal, and a polarity signal, and supplies the signal to the display unit 5 together with the image signal after crosstalk correction. To do.

  The display unit 5 displays the image signal after crosstalk correction based on the signal generated by the timing signal generation unit 4. Specifically, the display unit 5 displays the first and second images in different directions based on the image signal after crosstalk correction.

Hereinafter, the display unit 5 and the image signal G will be described in detail.
The display unit 5 displays images in first and second directions different from each other, and has a structure in which a plurality of pixels each including one or more subpixels are arranged, and displays in the first direction. The sub-pixels to be displayed and the sub-pixels displayed in the second direction are arranged alternately.

  The image signal G is an image obtained by combining the first and second images displayed in different directions, and a plurality of pixels each including one or more sub-pixels are arranged to form the first image. This is a signal representing the gradation value of each sub-pixel of an image in which sub-pixels and sub-pixels constituting the second image are alternately arranged. It can be said that the image signal G is a signal representing a gradation value corresponding to each sub-pixel of the display unit 5.

  Each sub pixel of the display unit 5 displays light of a gradation level corresponding to the gradation value based on the gradation value of the sub pixel of the image signal corresponding to the sub pixel. More specifically, the sub-pixel displayed in the first direction of the display unit 5 has the gradation value based on the gradation value of the sub-pixel constituting the first image of the image signal G corresponding to the sub-pixel. The light of the gradation level corresponding to is displayed in the first direction. The sub-pixels displayed in the second direction of the display unit 5 are based on the gradation values of the sub-pixels constituting the second image of the image signal G corresponding to the sub-pixels. Tone level light is displayed in the second direction. Thereby, the first image is displayed in the first direction, and the second image is displayed in the second direction.

  In one mode, for the display unit 5 and the image signal G, one pixel includes three sub-pixels of red (R: Red), green (G: Green), and blue (B: Blue). The plurality of pixels are two-dimensionally arranged in two different directions (for example, the horizontal direction and the vertical direction). Further, the sub-pixels constituting the first image and the sub-pixels constituting the second image are alternately arranged for each sub-pixel in the two different directions.

  FIG. 2 is a schematic plan view showing an example of the configuration of the display unit 5. In FIG. 2, the display unit 5 has a structure including a liquid crystal display device and a checkered (also referred to as checkerboard) parallax barrier, and can display two screens. Specifically, the display unit 5 includes a backlight 21, a liquid crystal panel 22, and a parallax barrier 23. In the liquid crystal panel 22, a group of R, G, and B subpixels constitutes one pixel, and a plurality of pixels are arranged in order. The parallax barrier 23 is configured such that sub-pixels displayed on the left viewer 24 toward the liquid crystal panel 22 and sub-pixels displayed on the right viewer 25 toward the liquid crystal panel 22 alternate for each sub-pixel. The light of each sub-pixel is shielded so as to be arranged in the array. Therefore, when viewing the display unit 5 from the direction of the left viewer 24, the liquid crystal panel 22 is shielded for each sub-pixel by the parallax barrier 23, and the left half image area of the net half of the liquid crystal panel 22 is visible. It is. On the other hand, when the display unit 5 is viewed from the direction of the viewer 25 on the right side, the sub-pixels that are shielded in the direction of the viewer 24 are visible, and the sub-pixels that are visible to the viewer 24 are shielded. In addition, the area for the right half image of the net half of the liquid crystal panel 22 is visible.

  2 shows a state in which a plurality of sub-pixels are arranged in the horizontal direction, the plurality of sub-pixels are arranged two-dimensionally in the horizontal and vertical directions. Further, the parallax barrier 23 is arranged such that the sub-pixels displayed to the left viewer 24 and the sub-pixels displayed to the right viewer 25 are alternately arranged for each sub-pixel in the horizontal direction and the vertical direction. In addition, it has a checkered structure.

  FIG. 3 is a diagram illustrating an example of the sub-pixel arrangement of the image signal G. The sub-pixel arrangement of the image signal G corresponds to the display unit 5 in FIG. 2, and has a structure in which two images are combined in a checkered pattern in units of sub-pixels. In FIG. 3, each square represents a subpixel. The first row of each subpixel cell indicates an image (or viewing direction in which the subpixel is displayed) formed by the subpixel, and “L” indicates a left image (or a left image to be presented to the left viewer) “R” means the right image (or right direction) to be presented to the right viewer. The second row of the square of each subpixel indicates the coordinates of the pixel including the subpixel, and each coordinate includes a horizontal coordinate value x and a vertical coordinate value y. Also, the third row of each subpixel cell indicates the color (R, G, B) of the subpixel.

  In FIG. 3, a group of R, G, and B subpixels constitutes one pixel, and a plurality of subpixels are two-dimensionally arranged in the horizontal and vertical directions. Further, the sub-pixels constituting the left image and the sub-pixels constituting the right image are alternately arranged for each sub-pixel in the horizontal direction and the vertical direction.

  For example, as shown in FIG. 3, such an image signal G is obtained by selecting the gradation values of the sub-pixels of the original image signal GL of the left image and the original image signal GR of the right image in a checkered pattern. Obtained by synthesis. Specifically, for even lines (lines with an even coordinate value y), the left image R, the right image G, the left image B, the right image R,... For the line with an odd value y), the gradation of the sub-pixels of the two image signals GL, 1R in the order of R of the right image, G of the left image, B of the right image, R of the left image,. It is obtained by combining values.

Hereinafter, electrical crosstalk and optical crosstalk will be described.
Electrical crosstalk is generated when an electrical signal for a certain sub-pixel electrically affects adjacent sub-pixels. For example, in a liquid crystal display device in which a plurality of source lines (signal lines) and a plurality of gate lines (scanning lines) are arranged in a matrix and sub-pixels are provided corresponding to the intersections of the source lines and the gate lines, It is considered that the crosstalk is caused by the influence of capacitive coupling due to parasitic capacitance between source lines and gate lines of adjacent subpixels. The influence of this electrical crosstalk appears when the voltage value of the affected sub-pixel shifts from the voltage value corresponding to the gradation value of the sub-pixel, and the amount of light emitted from the sub-pixel changes.

  On the other hand, optical crosstalk occurs when image light to be presented in one direction leaks in another direction. For example, in a direction-specific image or stereoscopic image display device using a parallax barrier, it is considered that there are two types of optical crosstalk due to the structure. The first is due to light diffraction by the slit, and the other is due to light reflection by the parallax barrier.

  FIG. 4 is a diagram showing crosstalk due to light diffraction. The sub-pixel 41 of the liquid crystal panel 40 is a sub-pixel that should be shielded leftward by the parallax barrier 42 toward the liquid crystal panel 40. However, since the space between the parallax barrier 42 and the adjacent parallax barrier 43 is sufficiently narrow, a diffraction phenomenon occurs, and the light of the sub-pixel 41 wraps around like the diffracted light path 44 and leaks to the left side that should be originally shielded. End up.

  FIG. 5 is a diagram showing crosstalk due to light reflection. The sub-pixel 51 of the liquid crystal panel 50 is a sub-pixel that should be shielded from the left side toward the liquid crystal panel 50 by the parallax barrier 52. However, the light of the sub-pixel 51 is reflected by the parallax barrier 52 and further reflected by the surface of the sub-pixel 53 adjacent to the sub-pixel 51, so that it leaks to the left side to be originally shielded like the reflected light path 54. End up.

  FIG. 6 is a diagram showing a sub-pixel arrangement of the image signal G, which is a part of the image signal G (5 × 5 pixels) in FIG. 3 cut out. Hereinafter, with reference to FIG. 6, a description will be given of a sub-pixel that has a crosstalk effect on a certain sub-pixel of interest (hereinafter referred to as “target sub-pixel”).

  In the following description, for a certain pixel, a pixel adjacent to the pixel is referred to as an “adjacent pixel”, and pixels around the adjacent pixel are referred to as “peripheral pixels”. For example, in FIG. 6, a pixel that surrounds the pixel at coordinates (x, y) in the center and is adjacent in the vertical, horizontal, or diagonal directions is referred to as an “adjacent pixel”, and the adjacent pixel is The surrounding pixels are called “surrounding pixels”. FIG. 7 shows 8 adjacent pixels, and FIG. 8 shows 16 surrounding pixels.

  The electrical crosstalk is greatly influenced by subpixels adjacent to the target subpixel. In addition, the influence of electrical crosstalk appears in a form in which the light emission of the target subpixel itself changes regardless of the color and display direction of the subpixel. Accordingly, the target sub-pixel is affected by electrical crosstalk from the sub-pixels adjacent to the sub-pixel, regardless of the difference in color or display direction between the sub-pixels.

  Specifically, in a liquid crystal display device in which source lines and gate lines are arranged in a matrix, the target sub-pixel includes two sub-pixels and gate lines adjacent to the sub-pixel in the source line direction (lateral direction). Two subpixels adjacent in the direction (vertical direction), that is, a total of four subpixels adjacent vertically and horizontally, are affected by electrical crosstalk. For example, in FIG. 6, G subpixels at coordinates (x, y) are R and B subpixels at coordinates (x, y), G subpixels at coordinates (x, y−1), It is affected by electrical crosstalk from the G color sub-pixel at the coordinates (x, y + 1).

  Regarding optical crosstalk, the subpixel of interest can be affected by subpixels located in various directions with respect to the subpixel, such as up and down, left and right, and oblique directions. Further, the target sub-pixel may be affected by optical crosstalk from a wide range of sub-pixels. Specifically, the target sub-pixel can be affected by optical crosstalk not only from the sub-pixels of the adjacent pixels to the pixel including the sub-pixel but also from the sub-pixels of the surrounding pixels. In particular, in a display device that displays two different images in different directions on the same display screen, the light of each sub-pixel is made stronger than a normal display device in order to ensure the brightness of the screen displayed in one direction. Often to do. Specifically, in a direction-specific image or a stereoscopic image display device, in order to prevent the brightness of a screen displayed in one direction from being lowered due to a structure such as a parallax barrier, the normal display device is arranged only at the bottom. In many cases, a backlight system that can emit more intense light is used, for example, by arranging two backlights at the top and bottom. As described above, since the light emission of each sub-pixel is increased, the range covered by the optical crosstalk becomes wide.

  Also, the effect of optical crosstalk is that, among the subpixels presented in a different direction from the target subpixel, the light of the subpixel of the same color as the target subpixel is superimposed on the light of the target subpixel, thereby It appears in a form in which the gradation level of the visually recognized subpixel changes.

  Therefore, for optical crosstalk, the subpixel of interest is presented in a different direction from the image formed by the subpixel included in the pixel adjacent to the pixel in which the subpixel is included and in the pixels around the adjacent pixel. (That is, forming an image different from the sub-pixel), the sub-pixel having the same color as the sub-pixel is affected by crosstalk.

  For example, when light of a certain sub-pixel has an optical crosstalk effect up to two pixels ahead, the G-color sub-pixel in the R direction at the coordinates (x, y) in FIG. 6 is as shown in FIG. 12 pixels of the same G color as the sub-pixel displayed in the L direction different from the sub-pixel included in the adjacent pixel and the surrounding pixels with respect to the pixel of the coordinates (x, y) including the sub-pixel. The sub-pixel is affected by optical crosstalk. In FIG. 9, the broken line 90 indicates the range of influence of the optical crosstalk of the G subpixel in the L direction at the coordinates (x−1, y−2), and the broken line 91 indicates the coordinates (x−2, y−). The range of influence of optical crosstalk of G subpixels in the L direction in 1) is shown. The G-color sub-pixel in the R direction at coordinates (x, y) is the G-color sub-pixel in the L direction at coordinates (x-1, y-2) and the L direction in the coordinates (x-2, y-1). This is within the range of influence of optical crosstalk of the G color sub-pixel.

Hereinafter, correction of crosstalk by the crosstalk correction unit 2 will be described.
When the correction target sub-pixel is affected by electrical or optical crosstalk from other sub-pixels, the visible gradation level of the correction target sub-pixel is affected by the cross-talk from other sub-pixels. Deviation from the original gradation level corresponding to the gradation value of the sub-pixel to be corrected. Therefore, the crosstalk correction unit 2 corrects the gradation value of the correction target sub-pixel so as to cancel the difference in the visually recognized gradation level.

  For example, if the number of gradations of the sub-pixel of the image signal G is 256 (8 bits), the gradation value of the correction target sub-pixel A is 15, and the sub-pixel B that affects the sub-pixel A has crosstalk. Is the gradation value of 243. When these sub-pixels are displayed as they are on the display unit 5, the light emission of the sub-pixel A becomes a gradation level corresponding to the gradation value 18 due to the influence of crosstalk from the sub-pixel B, and is about +3 from the original gradation level. Light emission with a strong gradation level is visually recognized. Therefore, the crosstalk correction unit 2 corrects the gradation value of the sub-pixel A by -3 to be 12. Thereby, when the influence +3 due to crosstalk occurs, the gradation level visually recognized by the sub-pixel A becomes a gradation level corresponding to the gradation value 15 that is the original gradation level. As described above, the crosstalk correction unit 2 performs correction to reduce the gradation value of the correction target sub-pixel when the visually recognized gradation level is higher than the original level (that is, when the light emission is strongly visually recognized). . Note that there is a case where the visually recognized gradation level is smaller than the original level (that is, when the light emission is viewed weakly). In this case, the crosstalk correction unit 2 determines the gradation value of the correction target sub-pixel. Perform correction to increase.

  The degree of deviation of the visually recognized gradation level depends on the gradation value of the sub-pixel that affects the correction target sub-pixel. Therefore, the crosstalk correction unit 2 corrects the gradation value of the correction target sub-pixel based on the gradation value of the sub-pixel that affects the sub-pixel. That is, for electrical crosstalk, the crosstalk correction unit 2 corrects the gradation value of the correction target sub-pixel based on the gradation value of the sub-pixel adjacent to the sub-pixel. For optical crosstalk, the crosstalk correction unit 2 includes the gradation value of the correction target sub-pixel included in the pixel adjacent to the pixel including the sub-pixel and the pixels around the adjacent pixel. Correction is performed based on the gradation value of a sub-pixel having the same color as that of the sub-pixel constituting an image different from the image formed by the sub-pixel.

  The degree of the visually recognized gradation level deviation also depends on the gradation value of the correction target sub-pixel. Therefore, in one aspect, the crosstalk correction unit 2 determines the gradation value of the subpixel to be corrected, the gradation value of the subpixel, and the gradation value of the subpixel that affects the subpixel. And correct based on Specifically, the crosstalk correction unit 2 obtains a correction value corresponding to a combination of the gradation value of the subpixel to be corrected and the gradation value of the subpixel that affects the subpixel. The correction value is added to the gradation value of the correction target sub-pixel to obtain a gradation value after crosstalk correction. The correction value is obtained using, for example, an LUT (lookup table).

  FIG. 10 is a diagram illustrating an example of an LUT used in the crosstalk correction unit 2. This LUT stores a correction value corresponding to a combination of a gradation value of a correction target sub-pixel and a gradation value of a sub-pixel having an influence of crosstalk on the sub-pixel. When a combination of a gradation value of a pixel and a gradation value of a sub-pixel that affects the sub-pixel is input, a corresponding correction value is output. From the viewpoint of reducing the size (number of bits) of the LUT, the LUT in FIG. 10 stores not a corrected gradation value but a correction value that is a difference between gradation values before and after correction. The correction value stored in the LUT is a value obtained by experiments. Note that the LUT correction value may include a component smaller than one gradation that can be expressed by the image signal G or the display unit 5 in order to perform finer correction. This is because such a correction component can also be visually recognized by the gradation converting unit 3.

  When correcting the crosstalk from a plurality of subpixels with respect to the correction target subpixel, the crosstalk correction unit 2 calculates the gradation value of the correction target subpixel based on the gradation value of the plurality of subpixels. to correct. For example, the crosstalk correction unit 2 obtains a correction value corresponding to a combination of the subpixel and the correction target subpixel for each of the plurality of subpixels having the influence of the crosstalk, and the obtained plurality of correction values. Is added to the gradation value of the sub-pixel to be corrected.

  FIG. 11 is a block diagram illustrating an example of the configuration of the crosstalk correction unit 2. Hereinafter, the configuration of the crosstalk correction unit 2 will be described with reference to FIG. In FIG. 11, the crosstalk correction unit 2 includes a sub-pixel selection unit 111 and a correction unit 112.

  The sub-pixel selection unit 111 receives the image signal G, and uses the gradation value of the sub-pixel to be corrected from the image signal G and the gradation value of the sub-pixel that affects the sub-pixel (that is, used for correction) Sub-pixel gradation value). Specifically, for electrical crosstalk, the subpixel selection unit 111 uses a total of four subpixels that are adjacent to the correction target subpixel in the vertical and horizontal directions as gradation values of subpixels that affect the crosstalk. Select the tone value of the pixel. For optical crosstalk, the sub-pixel selection unit 111 applies to the pixels adjacent to the pixel including the correction target sub-pixel and the pixels around the adjacent pixel as the gradation value of the sub-pixel that affects the cross-talk. A gradation value of a sub-pixel having the same color as that of the sub-pixel, which forms an image different from the image formed by the sub-pixel, is selected. For example, when the G subpixel in the R direction at the coordinates (x, y) in FIG. 6 is to be corrected, the subpixel selection unit 111 is adjacent to the pixel at the coordinates (x, y) shown in FIG. The gradation values of a total of 12 sub-pixels of the same G color as the sub-pixels displayed in the L direction different from the sub-pixels included in the pixels and surrounding pixels are selected.

  The correction unit 112 corrects the gradation value of the correction target sub-pixel selected by the sub-pixel selection unit 111 based on the gradation value of the sub-pixel having the influence of crosstalk selected by the sub-pixel selection unit 111. To do.

  The correction unit 112 includes an electrical crosstalk correction value generation unit 113, an optical crosstalk correction value generation unit 114, and a correction value addition unit 115.

  The electrical crosstalk correction value generation unit 113 corrects the electrical crosstalk based on the gradation value of the subpixel to be corrected and the gradation value of the subpixel that affects the electrical crosstalk on the subpixel. A correction value is generated for this purpose.

  The optical crosstalk correction value generation unit 114 corrects the optical crosstalk based on the gradation value of the subpixel to be corrected and the gradation value of the subpixel that affects the subpixel. A correction value is generated for this purpose.

  The correction value addition unit 115 uses the correction value generated by the electrical crosstalk correction value generation unit 113 and the correction value generated by the optical crosstalk correction value generation unit 114 as the gradation value of the sub-pixel to be corrected. And the tone value after the crosstalk correction of the correction target sub-pixel is output.

  In the example of FIG. 11, the electrical crosstalk correction value generation unit 113 includes a total of four electrical crosstalk correction LUTs 113 corresponding to a total of four subpixels that are adjacent vertically and horizontally to the correction target subpixel. -1 to 113-4. Each of the four electrical crosstalk correction LUTs 113-1 to 113-4 converts a combination of a gradation value of a sub-pixel to be corrected and a gradation value of a sub-pixel corresponding to the LUT into a correction value. And output to the correction value adder 115.

  The optical crosstalk correction value generation unit 114 includes a total of twelve optical crosstalk correction LUTs 114-1 to 114-12 corresponding to the subpixels affected by the total twelve optical crosstalks shown in FIG. Have The twelve optical crosstalk correction LUTs 114-1 to 114-12 each convert a combination of a gradation value of a correction target sub-pixel and a gradation value of a sub-pixel corresponding to the LUT into a correction value. And output to the correction value adder 115.

  The correction value adding unit 115 includes a total of four correction values output from the four electrical crosstalk correction LUTs 113-1 to 113-4 and twelve optical crosstalk correction LUTs 114-1 to 114-. The total 12 correction values output from 12 are added to the gradation value of the sub-pixel to be corrected, and the gradation value after crosstalk correction is output.

  In the above description, the case where the G sub-pixel is the correction target is illustrated, but the correction is similarly performed when the other color sub-pixel is the correction target.

  FIG. 12 is a flowchart showing the operation of the image display apparatus 100 according to the first embodiment. Hereinafter, an example of the operation of the image display apparatus 100 will be described with reference to FIG.

  The image display device 100 is an image obtained by combining first and second images displayed in different directions, and a plurality of pixels each including one or more sub-pixels are arranged to form a first image An image signal G representing a gradation value of each sub-pixel of an image in which sub-pixels to be configured and sub-pixels constituting the second image are alternately arranged is received (S1).

  Next, the image display apparatus 100 corrects electrical crosstalk and optical crosstalk for the image signal G (S2). Specifically, for optical crosstalk correction, the image display device 100 determines the gradation value of the sub-pixel to be corrected of the image signal G using the pixel adjacent to the pixel including the sub-pixel and the adjacent pixel. Is corrected based on the gradation values of sub-pixels of the same color as the sub-pixels that form an image different from the image formed by the sub-pixels included in the surrounding pixels.

Step S2 includes steps S2-1 and S2-2.
In step S 2-1, the image display apparatus 100 determines from the image signal G the gradation value of the correction target sub-pixel and the gradation value of the sub-pixel that has a crosstalk effect on the sub-pixel (that is, the sub-pixel used for correction). Pixel gradation value).
In step S2-2, the image display apparatus 100 uses the gradation value of the sub-pixel to be corrected selected in step S2-1 as the gradation of the sub-pixel that affects the crosstalk selected in step S2-1. Correct based on the value.

  Next, the image display device 100 displays the image signal corrected in step S2 (S3). Specifically, the image display apparatus 100 displays the first and second images in the first and second directions, respectively, based on the corrected image signal.

  As described above, in the present embodiment, the crosstalk correction unit includes the gradation value of the sub-pixel to be corrected in the pixel adjacent to the pixel including the sub-pixel and the pixels around the adjacent pixel. The correction is performed based on the gradation value of the sub-pixel of the same color as the sub-pixel that forms an image different from the image formed by the sub-pixel. For this reason, according to the present embodiment, it is possible to make it difficult to visually recognize optical crosstalk caused by adjacent pixels and surrounding pixels. Specifically, even if optical crosstalk occurs due to adjacent pixels and subpixels of surrounding pixels, correction that cancels the change in gradation level due to the crosstalk can be performed. Can be made difficult to see.

  In addition, when correction is performed using the gradation value of a sub-pixel located in an oblique direction with respect to the correction target sub-pixel, it is possible to correct optical crosstalk that occurs in the oblique direction.

  FIG. 13 shows images visually recognized when optical crosstalk correction is performed using only subpixels of adjacent pixels and when optical crosstalk correction is performed using subpixels of adjacent pixels and surrounding pixels. Shows the difference. When an image including an obliquely extending white line shown in FIG. 13A is input as an L direction image (left image), and a black solid image shown in FIG. 13B is input as an R direction image (right image), optical When the screen of the display unit 5 is viewed from the right direction without performing automatic crosstalk correction, lines (bright areas 131 and 132) extending obliquely as shown in FIG. 13C due to the influence of optical crosstalk. 133) can be visually recognized. Of the regions 131, 132, and 133, the region 132 is brighter than the regions 131 and 133. When correction is performed using only the sub-pixels of the adjacent pixels, as shown in FIG. 13D, only the central portion (region 132) of the lines that were visually recognized is not visible due to the correction. The diagonal lines (bright areas 131 and 133) are still visible around the area. Thus, when the correction is performed using only the sub-pixels of the adjacent pixels, the influence of the optical crosstalk due to the surrounding pixels remains, and the correction is insufficient. When the correction is performed using the adjacent pixels and the sub-pixels of the surrounding pixels, as shown in FIG. 13E, the diagonal line that has been visually recognized by the optical crosstalk is not completely visible. In the example of FIG. 13, optical crosstalk correction is performed after floating the black gradation value (for example, about +10) in order to make room for correction for the black sub-pixel having the gradation value of 0.

  In the above description, the pattern in which the sub-pixels constituting the first image and the sub-pixels constituting the second image are alternately arranged for each sub-pixel in the horizontal direction and the vertical direction is exemplified. The sub-pixels constituting the first image and the sub-pixels constituting the second image may be alternately arranged in other patterns. For example, the sub-pixels constituting the first image and the sub-pixels constituting the second image are alternately arranged for each sub-pixel in one of the horizontal direction and the vertical direction, and the same in the other directions. Only the sub-pixels constituting the image may be arranged. That is, the sub-pixel arrangement of the image signal G and the parallax barrier structure of the display unit 5 are not limited to the checkered pattern, but may be another pattern such as a stripe pattern. Further, the pattern is not limited to a pattern that is alternately arranged for each sub-pixel. For example, two sub-pixels may be alternately arranged, or the three sub-pixels constituting the first image may be One sub-pixel constituting the image may be alternately arranged.

Further, in the above description, a case where one pixel is composed of three sub-pixels of RGB is illustrated, but one pixel may be composed of one, two, or four or more sub-pixels. For example, one pixel may be composed of four sub-pixels obtained by adding yellow (Y) to RGB. In this case, the RGBY sub-pixels constituting the first and second images are arranged in the following patterns 1 and 2, for example.
(Pattern 1)
Sub-pixel color: RGBYGRYBRGBYGRYB
Image formed by sub-pixels: 1212121212121212
(Pattern 2)
Sub-pixel color: RGBYRGBYRGBYRGBY
Image formed by sub-pixels: 1212212112122121

  In the above description, the case where two images are displayed in different directions has been illustrated, but three or more images may be displayed in different directions. That is, the image signal to be processed may be a composite of three or more images, and in a structure in which the sub-pixels constituting the first image and the sub-pixels constituting the second image are alternately arranged. Sub-pixels constituting other images may be interposed.

  In the above description, the configuration including the liquid crystal panel is exemplified, but the crosstalk correction of the present embodiment can be applied to other types of electro-optical devices such as an organic EL (electroluminescence) device and a plasma display. It is.

  In the above description, the configuration for correcting the electrical crosstalk and the optical crosstalk is illustrated, but a configuration for correcting only the optical crosstalk may be used.

  In the above description, the configuration in which the optical crosstalk is corrected based on the gradation value of the sub-pixel included in the adjacent pixel and the gradation value of the sub-pixel included in the surrounding pixel is exemplified. It is also possible to make a correction based on the gradation value of the included sub-pixel and not use the gradation value of the sub-pixel included in the adjacent pixel for correction. In this configuration, it is possible to make it difficult to visually recognize optical crosstalk caused by surrounding pixels.

  In the above description, a configuration using a total of 16 LUTs has been exemplified, but the number of LUTs can be changed as appropriate. For example, from the viewpoint of reducing the capacity occupied by the LUTs, the following (1) to (6) As described above, the number of LUTs may be reduced.

  (1) For electrical crosstalk, one LUT may be shared for two vertical subpixels or two horizontal subpixels. As a result, the number of electrical crosstalk correction LUTs can be reduced from four to two.

  (2) It has been experimentally found that the electrical crosstalk has a particularly large influence in the source line direction, and has an influence of about 2 to 3 times that in the gate line direction. Therefore, the correction may be performed using only the LUT corresponding to the left and right subpixels having a large influence. Thus, the number of electrical crosstalk correction LUTs can be reduced from four to two, and when one LUT is shared for two subpixels in the left-right direction, the number can be further reduced to one.

  (3) Regarding electrical crosstalk, there is a tendency that the influence from adjacent sub-pixels on the downstream side in the scanning direction of an image is large. Therefore, when the image is scanned from the upper left to the lower right, only the LUT corresponding to the subpixels adjacent to the right (source line direction) and the lower (gate line direction) may be used. As a result, the number of electrical crosstalk correction LUTs can be reduced from four to two.

  (4) For optical crosstalk, in the sub-pixel selection unit 111, coordinates (x-1, y-2) and coordinates in the upper left direction with respect to the G-color sub-pixel at coordinates (x, y) in FIG. An average value of gradation values of G subpixels of (x−2, y−1) may be obtained, and one LUT may be used for this average value. That is, one LUT may be used in which the combination of the average value and the gradation value of the correction target sub-pixel is input data. Similarly, one LUT may be used for two subpixels in the upper right direction, the lower left direction, and the lower right direction. In this way, the number of optical crosstalk correction LUTs can be reduced from 12 to 8 by using one LUT for the average value of the gradation values of the two sub-pixels in each oblique direction.

  (5) For optical crosstalk, in the sub-pixel selecting unit 111, the coordinates (x-1, y) in the left direction and the upper-left direction with respect to the G-color sub-pixel at the coordinates (x, y) in FIG. Depending on the distance from the coordinate (x, y) to the gradation value of the G subpixel of the coordinate (x-2, y-1) and the coordinate (x-2, y + 1) in the lower left direction A weighted addition may be performed, and one LUT may be used for this result. Similarly, in the upper, lower, and right directions, the number of optical crosstalk correction LUTs can be reduced from 12 to 4 by using one LUT for the weighted addition result of three subpixels. Furthermore, if the influence of optical crosstalk by subpixels in the left and right direction is greater than that in the up and down direction, the LUT in the up and down direction can be eliminated, and the number of LUTs can be reduced to two, which is half.

  (6) When having a checkered parallax barrier structure, the same-color sub-pixels presented in the same direction are positioned closest to each other in the diagonal direction as shown in FIG. Become. When the resolution in the oblique direction is high in this way, the oblique direction looks sharp to the viewer, and since it looks sharp, the influence of crosstalk can be seen more clearly. Therefore, when the resolution in the oblique direction is high, it is included in the surrounding pixels as sub-pixels that affect cross-talk (that is, sub-pixels used for correction) for the purpose of focusing on optical cross-talk correction in the oblique direction. Only sub-pixels of the same color (a total of eight) located in an oblique direction may be used. In this case, further, the G color sub-pixel having the coordinates (x-1, y-2) and the coordinate (x-2, y-1) in the upper left direction with respect to the G color sub-pixel having the coordinates (x, y). An average value of gradation values of pixels may be obtained, and one LUT may be used for this average value. By performing the same processing for the upper right, lower left, and lower right directions, the number of optical crosstalk correction LUTs may be reduced to four.

Furthermore, you may use LUT like following (7) and (8).
(7) When a subpixel that affects crosstalk is selected by the subpixel selection unit 111 and the gradation value of the selected subpixel is input to each LUT together with the gradation value of the correction target subpixel, May be input to different LUTs depending on the direction in which the sub-pixels are presented. That is, different LUTs may be used depending on the direction in which the correction target sub-pixel is presented.
In the direction-specific image display device, the presentation direction may be biased depending on manufacturing problems or product specifications. In such a case, as described above, by changing the LUT used depending on the direction in which the correction target sub-pixel is presented, it is possible to perform correction suitable for the direction.

(8) Even in the same LUT, the subpixel to which the gradation value is input may be changed depending on the direction in which the correction target subpixel is presented. Specifically, when correcting a sub pixel presented in the L direction for a certain LUT, the gradation value of the sub pixel adjacent to the right direction of the sub pixel is input, and the sub pixel presented in the R direction is selected. In the case of correction, the gradation value of the sub pixel adjacent in the left direction of the sub pixel is input.
For example, in the case of optical crosstalk due to reflection, the position of the subpixel presented in the opposite direction that affects the correction target subpixel is reversed depending on the direction in which the viewer views the screen. As described above, by changing the subpixel in which the gradation value is input to the LUT depending on the direction in which the correction target subpixel is presented, it is possible to perform correction in consideration of the difference in the occurrence of crosstalk depending on the viewing direction. .

Embodiment 2. FIG.
FIG. 14 is a block diagram showing a configuration of the crosstalk correction unit 140 included in the image display apparatus according to the second embodiment of the present invention. Since the image display device of the present embodiment is almost the same as that of the first embodiment, in the following description, the same reference numerals are used for the same parts as those of the first embodiment, and the description is omitted or omitted. It will be simplified.

  Some sub-pixels that affect crosstalk on the correction target sub-pixels have both electrical and optical crosstalk effects. For example, in the sub-pixel arrangement of FIG. 6, sub-pixels adjacent above and below the correction target sub-pixel have both electrical crosstalk and optical crosstalk on the correction target sub-pixel.

  In the present embodiment, as shown in FIG. 14, the crosstalk correction unit 140 includes an electrical / optical crosstalk in addition to the electrical crosstalk correction value generation unit 113 and the optical crosstalk correction value generation unit 114. A correction value generation unit 141 is included.

  The electrical / optical crosstalk correction value generation unit 141 affects the gradation value of the subpixel to be corrected from the subpixel selection unit 111 and influences both the electrical crosstalk and the optical crosstalk on the subpixel. Based on the gradation values of the sub-pixels, a correction value for correcting both electrical crosstalk and optical crosstalk is generated based on these gradation values. This correction value is supplied to the correction value adding unit 115 and added to the gradation value of the correction target sub-pixel.

  In the example of FIG. 14, the electro / optical crosstalk correction value generation unit 141 includes a total of two electro / optical crosstalks corresponding to a total of two subpixels that are adjacent vertically to the correction target subpixel. It has correction LUTs 141-1 to 141-2. The two electro / optical crosstalk correction LUTs 141-1 to 141-2 each have a correction value obtained by combining a gradation value of a correction target sub-pixel and a gradation value of a sub-pixel corresponding to the LUT. And output to the correction value adder 115.

  Electrical crosstalk and optical crosstalk caused by subpixels vertically adjacent to the correction target subpixel are corrected by the correction values of the electro / optical crosstalk correction LUTs 141-1 to 141-2. Therefore, in the present embodiment, the electrical crosstalk correction value generation unit 113 includes subpixels that are adjacent in the vertical direction among the total of four electrical crosstalk correction LUTs 113-1 to 113-4 of the first embodiment. In other words, a total of two electrical crosstalk correction LUTs 113-1 to 113-2 are excluded, excluding the two electrical crosstalk correction LUTs 113-3 to 113-4 corresponding to. Further, the optical crosstalk correction value generation unit 114 includes two optical crosstalk correction LUTs 114-1 to 114-12 in total of the first embodiment, which correspond to the vertically adjacent subpixels. A total of ten optical crosstalk correction LUTs 114-1 to 114-10, excluding the optical crosstalk correction LUTs 114-11 to 114-12, are provided.

  The correction value adding unit 115 includes a total of two correction values output from the two electrical crosstalk correction LUTs 113-1 to 113-2 and ten optical crosstalk correction LUTs 114-1 to 114-. 10 total correction values output from 10 and two total correction values output from the two electro / optical crosstalk correction LUTs 141-1 to 141-2. The tone value after crosstalk correction is output by adding to the tone value.

  As described above, in the present embodiment, the crosstalk correction unit performs the gradation value of the subpixel to be corrected and the subpixel level that affects both the electric crosstalk and the optical crosstalk on the subpixel. Based on the key value, a correction value for correcting both electrical crosstalk and optical crosstalk is generated. For this reason, a correction value for correcting electrical crosstalk and a correction value for correcting optical crosstalk are separately generated for sub-pixels that affect both electrical crosstalk and optical crosstalk. Compared to the case, it is possible to reduce the amount of information for generating the correction value. Specifically, the number of LUTs can be reduced, and the capacity occupied by the LUT can be reduced.

Embodiment 3 FIG.
FIG. 15 is a block diagram schematically showing the configuration of the image display device 150 according to the third embodiment of the present invention. Since this image display device 150 is almost the same as that of the first embodiment, in the following description, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified. I will do it.

  In the present embodiment, the crosstalk correction unit 151 changes the correction amount of the correction by the crosstalk correction unit 151 according to the temperature of the image display device 150 or the temperature around the image display device 150. Specifically, the crosstalk correction unit 151 changes the correction value corresponding to the combination of the gradation values of the sub-pixels depending on the temperature of the image display device 150 or its surroundings.

  In the example of FIG. 15, the image display device 150 includes a temperature sensor 152 and an A / D converter 153. The temperature sensor 152 detects the temperature of the image display device 150 or its surroundings, and outputs an analog signal indicating the temperature to the A / D converter 153. The A / D converter 153 converts the analog signal from the temperature sensor 152 into temperature information T that is a digital signal, and supplies it to the crosstalk correction unit 151. The crosstalk correction unit 151 changes the correction amount of the crosstalk correction according to the temperature information T.

  FIG. 16 is a block diagram illustrating an example of the configuration of the crosstalk correction unit 151 according to the third embodiment. In FIG. 16, the crosstalk correction unit 151 includes an LUT data storage unit 161 and an LUT control unit 162.

  The LUT data storage unit 161 stores data for changing the correspondence between the gradation value of the sub-pixel indicated by the LUT and the correction value for each LUT of the crosstalk correction unit 151. Specifically, the LUT data storage unit 161 stores, for each LUT, LUT data corresponding to each temperature (data representing a conversion table indicating a correspondence relationship between gradation values of sub-pixels and correction values). . Specifically, the LUT data storage unit 161 includes a nonvolatile storage medium such as an EEPROM (Electrically Erasable and Programmable Read Only Memory).

  The LUT control unit 162 receives temperature information T indicating the temperature of the image display device 150 or its surroundings, and in accordance with the temperature information T, for each LUT of the crosstalk correction unit 151, the level of the sub-pixel indicated by the LUT. Change the correspondence between the key value and the correction value. Specifically, the LUT control unit 162 reads the LUT data of each LUT corresponding to the temperature information T from the LUT data storage unit 161, and rewrites each LUT based on the LUT data.

  As described above, in the present embodiment, the crosstalk correction unit 151 changes the correction amount of the crosstalk correction according to the temperature of the image display device or the temperature around the image display device. As a result, it is possible to perform appropriate crosstalk correction according to the temperature of the image display device or its surroundings. Specifically, by adjusting the correction value in the crosstalk correction process according to the temperature information, even if the characteristics of the image display device change depending on the temperature and the occurrence of crosstalk changes, an accurate crosstalk can be followed. Talk correction can be performed. That is, in the same manner as the gamma curve and the like change with temperature in the image display device, it becomes possible to cope with changes in the occurrence of electrical crosstalk and optical crosstalk, making it difficult to see double images due to crosstalk. .

  In the above description, the configuration in which the LUT control unit 162 reads the LUT data from the LUT storage unit 161 has been exemplified. However, the LUT data generated by the LUT control unit 162 by a microcomputer (not shown) of the image display device 150 is calculated. It is good also as a structure which receives. In such a configuration, the LUT storage unit 161 may be omitted.

  In the above description, the configuration corresponding to the temperature change is illustrated by rewriting the LUT. However, the crosstalk correction unit 151 includes a plurality of LUTs corresponding to different temperatures, and the temperature is indicated by the temperature information T. When the corresponding LUT exists, the correction value may be obtained by the LUT, and when the LUT corresponding to the temperature does not exist, the correction value may be obtained by interpolation. For example, the crosstalk correction unit 151 includes a 0 ° C. LUT and a 30 ° C. LUT. If the temperature information T indicates 0 ° C. or 30 ° C., the 0 ° C. LUT or 30 ° C. LUT When the correction value is obtained using the LUT and the temperature information T indicates a temperature between 0 ° C. and 30 ° C. (for example, 15 ° C.), the temperature (for example, 15 ° C.) is calculated from the correction values obtained from the two LUTs. The correction value corresponding to may be obtained by interpolation.

  In the above description, the configuration in which each LUT of the crosstalk correction unit is changed is illustrated. However, only a part of the LUT for the crosstalk correction unit is changed, for example, only the optical crosstalk correction LUT is changed. It is good.

  Further, the configuration of the present embodiment, that is, the configuration in which the correction amount is changed depending on the temperature, may be applied to the image display device of the second embodiment. In this case, the crosstalk correction unit changes a correction value for correcting both the electric crosstalk and the optical crosstalk, such as rewriting of the LUT for electric / optical crosstalk correction.

Embodiment 4 FIG.
FIG. 17 is a block diagram schematically showing the configuration of the image display device 170 according to the fourth embodiment of the present invention. Since this image display device 170 is almost the same as that of the first embodiment, in the following description, the same reference numerals are used for the same parts as those of the first embodiment, and the description is omitted or simplified. I will do it.

  In the present embodiment, the display unit 5 is a liquid crystal display device having a backlight that illuminates a sub-pixel array such as a liquid crystal panel from the back.

  The degree of light emission of the backlight is directly related to the degree of light emission of each sub-pixel. Further, it can be said that the degree of light emission of each sub-pixel is closely related to the degree of occurrence of optical crosstalk. For example, in FIGS. 4 and 5, the stronger the light emission of the sub-pixel, the greater the light leakage due to diffraction and reflection. On the contrary, if the light emission of the sub-pixel becomes weak, light leakage due to diffraction and reflection is also reduced.

  Therefore, in the present embodiment, the crosstalk correction unit 171 changes the correction amount of the correction by the crosstalk correction unit 171 in accordance with the light emission amount of the backlight of the display unit 5. Specifically, the crosstalk correction unit 171 changes the correction value corresponding to the combination of the gradation values of the sub-pixels according to the light emission amount of the backlight of the display unit 5.

  The amount of light emitted from the backlight changes by being controlled by the image display device 170, for example. In the example of FIG. 17, the image display device 170 includes an average luminance calculation unit 172 and a backlight adjustment signal generation unit 173.

  The average luminance calculating unit 172 receives the image signal G and calculates the average luminance of the image signal G. Specifically, the average luminance calculation unit 172 obtains the average value of the luminance values Y when the RGB gradation values of the image signal G are converted into YCbCr coordinate values as the average luminance.

  The backlight adjustment signal generation unit 173 generates a backlight adjustment signal that is, for example, a PWM (Pulse Width Modulation) signal in accordance with the average luminance of the image signal G calculated by the average luminance calculation unit 172. The display unit 5 adjusts the light emission degree of the backlight based on the backlight adjustment signal generated by the backlight adjustment signal generation unit 173.

  With such control, for example, when displaying an image with many black areas and low average luminance on the display unit 5, the backlight adjustment signal is adjusted to weaken the light emission of the backlight, thereby expressing a tighter black. It becomes possible.

  In addition to the image signal G, the crosstalk correction unit 171 receives a backlight adjustment signal from the backlight signal generation unit 173, and performs crosstalk correction based on the backlight adjustment signal.

  FIG. 18 is a block diagram illustrating an example of a configuration of the crosstalk correction unit 171 according to the fourth embodiment. In FIG. 18, the crosstalk correction unit 171 includes a correction value adjustment unit 180.

  The correction value adjustment unit 180 adjusts the correction values output from the optical crosstalk correction LUTs 114-1 to 114-12 of the crosstalk correction unit 171 according to the backlight adjustment signal, and sets the corrected correction values. The correction value is added to the correction value adding unit 115. For example, the correction value adjustment unit 180 obtains an adjusted correction value by multiplying the correction value from the LUT by a coefficient corresponding to the backlight adjustment signal. For example, the correction value adjustment unit 180 adjusts the correction value so that the absolute value of the corrected correction value increases as the backlight emission increases.

  As described above, in the present embodiment, the correction amount of correction by the crosstalk correction unit is changed according to the light emission amount of the backlight. Thereby, it is possible to perform appropriate crosstalk correction according to the light emission amount of the backlight. Specifically, even if the occurrence of crosstalk changes due to a change in the light emission level of the backlight, accurate crosstalk correction can be performed following the change. Thereby, the double image by crosstalk becomes difficult to visually recognize.

  In the above description, since it is a correction value for correcting the optical crosstalk that needs to be particularly adjusted in accordance with the light emission amount of the backlight, the correction value of the optical crosstalk correction LUT is set as follows. The configuration to be changed is exemplified. However, electrical crosstalk may also be related to the light emission level of the sub-pixel, and the crosstalk correction unit changes the correction value of the electrical crosstalk correction LUT according to the amount of light emitted from the backlight. Also good.

  In addition, the configuration of the present embodiment, that is, the configuration in which the correction amount is changed in accordance with the light emission amount of the backlight may be applied to the image display device of the second or third embodiment. When applied to the image display apparatus according to the second embodiment, the crosstalk correction unit adjusts correction values output from the electro / optical crosstalk correction LUT, and performs both electrical crosstalk and optical crosstalk. The correction value for correcting the correction is changed.

Embodiment 5 FIG.
In the present embodiment, an apparatus or method that makes it difficult to visually recognize crosstalk by performing processing suitable for each direction even when the occurrence state of crosstalk varies depending on the display direction of the image will be described.

  FIG. 19 is a block diagram schematically showing the configuration of the image display device 190 according to the fifth embodiment of the present invention. Since this image display device 190 is similar to that of the first embodiment, in the following description, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified. To do.

  In FIG. 19, the image display device 190 includes an input terminal 1, a crosstalk correction unit 191, a gradation conversion unit 3, a timing signal generation unit 4, and a display unit 192.

  The input terminal 1, the gradation converting unit 3, and the timing signal generating unit 4 are the same as those in the first embodiment.

  The display unit 192 is substantially the same as the display unit 5 of the first embodiment, and displays the first and second images in the first and second directions, respectively. However, in the present embodiment, the display unit 192 has a characteristic that a crosstalk occurrence state varies depending on an image display direction. For example, the display unit 192 has different (or asymmetric) optical characteristics (for example, luminance characteristics) in the first direction and the second direction. Specifically, the display unit 192 is configured to display the first and second images in different asymmetric directions.

  The crosstalk correction unit 191 is substantially the same as the crosstalk correction unit 2 of the first embodiment, and an image signal G representing the gradation value of each sub-pixel of an image obtained by combining the first and second images. And the gradation value of the sub-pixel of the image signal G is corrected so that the crosstalk between the first and second images is less visible. However, in the present embodiment, the crosstalk correction unit 191 changes the correction amount for the gradation value of the correction target sub-pixel according to the direction in which the sub-pixel is displayed.

  FIG. 20 is a diagram illustrating an example of a usage pattern of the image display device 190. FIG. 20 shows a case where the image display device 190 is used in an automobile 206. A driver's seat 200, a passenger seat 201, and a display unit 192 of the image display device 190 are disposed in the interior of the automobile 206.

  In FIG. 20, the broken line 205 indicates the center line in the left-right direction in the interior of the automobile 206, and the driver's seat 200 and the passenger seat 201 are in symmetrical positions with respect to the broken line 205. The display unit 192 is installed closer to the driver's seat 200 with respect to the broken line 205 due to circumstances such as the design of the interior of the automobile. Therefore, the angle when viewing the display unit 192 from the driver seat 200 (specifically, the viewing direction when viewing the display surface of the display unit 192 from the driver seat 200 and the display surface of the display unit 192 from the front. And the angle when viewing the display unit 192 from the passenger seat 201 (specifically, the viewing direction when viewing the display surface of the display unit 192 from the passenger seat 201) And the angle 204 formed by the line of sight when the display surface of the display unit 192 is viewed from the front. For this reason, the display unit 192 is configured to display the first and second images, that is, the image presented to the person in the driver's seat 200 and the image presented to the person in the passenger seat 201 in an asymmetrical direction. Is done.

  FIG. 21 is a diagram illustrating an example of the structure of the display unit 192 that displays the first and second images in different asymmetric directions. In FIG. 21, the display unit 192 includes a backlight 21, a liquid crystal panel 22, and a parallax barrier 213. Assume that the viewer 210 on the right side is viewing the display unit 192 from the position of the driver seat 200 and the viewer 211 on the left side is viewing the display unit 192 from the position of the passenger seat 201. For comparison, in FIG. 21, the position of the parallax barrier 23 shown in FIG.

  In FIG. 2, the left viewer 24 and the right viewer 25 are drawn assuming that they are in a symmetric direction with respect to the liquid crystal panel 22. In FIG. 21, when the parallax barrier is at the position of the broken line 212, when the liquid crystal panel 22 is viewed from the viewer 211 on the left side, a part of the image that should be originally viewed is blocked by the parallax barrier. In order to prevent this, in FIG. 21, the parallax barrier 213 is arranged at a position shifted to the left side from the position of the broken line 212.

  21 shows an example in which the first and second images are displayed in the left-right asymmetric direction by adjusting the position of the parallax barrier, but the first and second images are displayed in the left-right asymmetric direction. The structure to perform may be implement | achieved in another aspect. For example, it may be realized by adjusting the structure of the lenticular lens according to the left and right display directions, or adjusting the position of the liquid crystal color filter opening with respect to the parallax barrier according to the display direction of each sub-pixel. It may be realized with.

  FIG. 22A shows the luminance distribution of the display unit 192 that displays the first and second images in the left-right asymmetric direction as described above. FIG. 22B shows the luminance distribution of the display unit that displays the first and second images in a bilaterally symmetric direction.

  FIG. 23 is a diagram illustrating a method of measuring the luminance distribution shown in FIGS. 22 (a) and 22 (b). FIG. 23 shows a display surface 230 of a display unit to be measured and a luminance meter 231 that measures the luminance of the display unit. The luminance distribution of the display unit is determined by moving the position of the luminance meter 231 in the horizontal direction as indicated by an arrow 234 while directing the light receiving unit 232 of the luminance meter 231 toward a specific point (for example, the center point) 233 of the display surface 230. It is obtained by measuring the luminance of the display unit with a luminance meter 231 from each direction. In FIG. 23, the luminance meter 231 positioned in front of the display surface 230 is indicated by a solid line, and the luminance meter 231 positioned on the left side and right side of the display surface 230 is indicated by a one-dot chain line. When the luminance meter 231 is moved from side to side, the angle in the vertical direction of the optical axis 235 of the luminance meter 231 with respect to the display surface 230 is fixed, for example, the optical axis 235 is kept horizontal. Further, the distance from the light receiving unit 232 of the luminance meter 231 to the display surface 230 is kept constant.

  22A and 22B, the horizontal axis indicates the measurement direction (for example, the angle of the optical axis 235 of the luminance meter 231 with respect to the normal line of the display surface 230), and the vertical axis indicates the luminance.

  In FIG. 22B, luminance peaks appear in the measurement direction 221 and the measurement direction 222, and these directions indicate directions in which the first and second images are displayed, respectively. The measurement direction 221 and the measurement direction 222 are in symmetrical positions with respect to the front, and the peak luminances 223 in the respective measurement directions are substantially equal. Note that the low luminance when viewed from the front is due to the structure of a parallax barrier or the like.

  On the other hand, in FIG. 22A, the measurement direction 224 and the measurement direction 225 in which the luminance peak appears are in asymmetric positions on the left and right with respect to the front. This indicates that the first and second images are displayed in an asymmetric direction. For example, in the display unit 192, the direction 224 matches the direction when viewing the display surface of the display unit 192 from the driver seat 200, and the direction 225 matches the direction when viewing the display surface of the display unit 192 from the passenger seat 201. Configured as follows.

In FIG. 22A, there is also a difference between the peak luminance 226 in the measurement direction 224 and the peak luminance 227 in the measurement direction 225. This is because the backlight is generally brightest in the front and darker as the measurement direction deviates from the front, and the measured luminance tends to increase as the measurement direction in which the peak luminance appears is closer to the front. However, the difference in peak luminance can be reduced by providing directivity to the backlight.
As described above, the display unit 192 displays the first and second images in the left and right directions with respect to the display surface of the display unit 192, and is asymmetrical with respect to the display surface. Has luminance characteristics.

  In addition, although the case where the first and second images are presented in an asymmetrical direction to the left and right has been described here, the range in which the first image can be seen and the range in which the second image can be seen are also included. Even when a difference is added, the luminance characteristics of the display unit are left-right asymmetric.

  Due to the left-right asymmetric optical characteristics of the display unit 192 described above, the optical crosstalk generated in the display unit 192 is also asymmetric in the left-right direction. In order to cope with this, the crosstalk correction unit 191 is configured to apply different correction amounts depending on the direction in which the correction target sub-pixel is displayed. For example, when the crosstalk correction unit 191 corrects the gradation value of the correction target subpixel using a correction value according to the gradation values of the subpixels around the subpixel, the correction target subpixel is The correction value is changed according to the displayed direction. Here, as the sub-pixels around the correction target sub-pixel, for example, the sub-pixel included in the pixel (adjacent pixel) adjacent to the pixel including the correction target sub-pixel, or the pixel ( There are sub-pixels included in the surrounding pixels.

  FIG. 24 is a block diagram illustrating an example of the configuration of the crosstalk correction unit 191. In the example of FIG. 24, the crosstalk correction unit 191 is configured to change the LUT used for crosstalk correction according to the direction in which the correction target sub-pixel is displayed. In FIG. 24, the crosstalk correction unit 191 includes a sub-pixel selection unit 111 and a correction unit 112. The correction unit 112 includes an electrical crosstalk correction value generation unit 113, a left direction display sub-pixel optical crosstalk correction value generation unit (hereinafter referred to as a "left direction optical crosstalk correction value generation unit") 240, It has an optical crosstalk correction value generation unit for right direction display subpixels (hereinafter referred to as “right direction optical crosstalk correction value generation unit”) 241, a correction value selector 242, and a correction value addition unit 115.

  The sub-pixel selection unit 111 is the same as that of the first embodiment, and the gradation value of the sub-pixel to be corrected from the image signal G, and the gradation value of the sub-pixel that has an effect of crosstalk on the sub-pixel Select. Specifically, the sub-pixel selection unit 111 selects the gradation value of the correction target sub-pixel and the gradation value of the sub-pixel that affects the sub-pixel, and the electric cross-talk. It outputs to the correction value generation unit 113. Further, the sub-pixel selection unit 111 selects the gradation value of the sub-pixel to be corrected and the gradation value of the sub-pixel that has an optical crosstalk effect on the sub-pixel, so that the optical cross for the left direction is selected. The data is output to the talk correction value generation unit 240 and the optical crosstalk correction value generation unit 241 for the right direction.

  The electrical crosstalk correction value generation unit 113 is the same as that in the first embodiment, and the gradation value of the correction target sub-pixel and the gradation of the sub-pixel that affects the sub-pixel. Based on the value, a correction value for correcting the electrical crosstalk is generated and output to the correction value adding unit 115. In the example of FIG. 24, the electrical crosstalk correction value generation unit 113 includes four electrical crosstalk correction LUTs 113-1 to 113-4, as in FIG.

  The left-direction optical crosstalk correction value generation unit 240 and the right-direction optical crosstalk correction value generation unit 241 each have the gradation value of the correction target sub-pixel and the influence of optical cross-talk on the sub-pixel. The correction value for correcting the optical crosstalk is generated based on the gradation value of the sub-pixel that gives Also, the left-direction optical crosstalk correction value generation unit 240 and the right-direction optical crosstalk correction value generation unit 241 have different LUTs, and each has a correction value for a sub-pixel displayed in the left direction. And a right correction value that is a correction value for a sub-pixel displayed in the right direction.

  In the example of FIG. 24, the left-side optical crosstalk correction value generation unit 240 has a total of twelve left-side opticals corresponding to the sub-pixels affected by a total of twelve optical crosstalks shown in FIG. Crosstalk correction LUTs 240-1 to 240-12. The twelve left-hand optical crosstalk correction LUTs 240-1 to 240-12 each correct a combination of a gradation value of a correction target sub-pixel and a gradation value of a sub-pixel corresponding to the LUT. The value is converted into a value, and the correction value is output to the correction value selector 242 as a left correction value. Similarly, the right-direction optical crosstalk correction value generation unit 241 generates a total of twelve right-direction optical crosstalks corresponding to the sub-pixels affected by the total twelve optical crosstalks shown in FIG. It has correction LUTs 241-1 to 241-12. The twelve rightward optical crosstalk correction LUTs 241-1 to 241-12 each correct a combination of a gradation value of a correction target sub-pixel and a gradation value of a sub-pixel corresponding to the LUT. The value is converted into a value, and the correction value is output to the correction value selector 242 as the right correction value.

  The correction value selector 242 outputs the left-direction optical crosstalk correction value generation unit 240 and the right-direction optical crosstalk correction according to the display direction of the correction target sub-pixel selected by the sub-pixel selection unit 111. One of the outputs of the value generation unit 241 is selected and output to the correction value addition unit 115. For example, when the first image is displayed in the left direction and the second image is displayed in the right direction, the correction value selector 242 determines that the correction target selector 242 is left when the correction target sub-pixel is a sub-pixel of the first image. When the left-side correction value generated by the direction optical crosstalk correction value generation unit 240 is output and the correction target sub-pixel is a sub-pixel of the second image, the right-direction optical crosstalk correction value generation unit The right correction value generated in step 241 is output.

  The display direction of the correction target subpixel is uniquely determined by the coordinates (x, y) of the subpixel and the structure of the display unit 192. Therefore, for example, the correction value selector 242 can count up the coordinate counter together with the input of the correction value, and know the display direction of the correction target sub-pixel from the coordinate counter.

  The correction value addition unit 115 is the same as that of the first embodiment, and the correction value output from the electrical crosstalk correction value generation unit 113 and the correction value output from the correction value selector 242 are corrected. By adding to the gradation value of the sub-pixel, the gradation value after the crosstalk correction of the sub-pixel to be corrected is output.

  The operation of the image display device 190 of the fifth embodiment is substantially the same as the operation of the image display device 100 of the first embodiment shown in FIG. However, in the present embodiment, the image display device 190 changes the correction amount for the gradation value of the correction target sub-pixel according to the direction in which the sub-pixel is displayed in step S2 of FIG.

  FIG. 25 is a flowchart illustrating the crosstalk correction processing of the image display apparatus 190 according to the fifth embodiment. The process shown in FIG. 25 is executed in step S2 of FIG.

  The image display device 190 determines from the image signal G the gradation value of the sub-pixel to be corrected and the gradation value of the sub-pixel that affects the sub-pixel (that is, the gradation value of the sub-pixel used for correction). Are selected (S251).

  Next, the image display device 190 generates a correction value for electrical crosstalk correction, a correction value for left and a correction value for right for optical crosstalk correction, based on the gradation value selected in step S251. (S252).

  Next, the image display device 190 determines whether the display direction of the correction target sub-pixel is the left direction or the right direction (S253).

  When it is determined that the direction is the left direction (S253: left direction), the image display device 190 uses the electrical cross generated in step S252 for the gradation value of the correction target sub-pixel selected in step S251. Correction is performed based on the correction value for talk correction and the left correction value for optical crosstalk correction (S254).

  On the other hand, when it is determined that the direction is the right direction (S253: right direction), the image display apparatus 190 uses the electrical cross generated in step S252 for the gradation value of the correction target sub-pixel selected in step S251. Correction is performed based on the correction value for talk correction and the right correction value for optical crosstalk correction (S255).

  By the way, when the occurrence state of crosstalk varies depending on the image display direction, the position and range of the subpixel that affects the correction target subpixel may vary depending on the image display direction. For example, when the optical crosstalk generated in the display unit 192 occurs asymmetrically in the left-right direction, the range covered by the optical crosstalk on one side may be wider than the other side. For example, when one image is displayed in a direction closer to the front, since the image is viewed from a shallow angle with respect to the slit of the parallax barrier, the image is easily affected by light diffraction. The sub-pixel is affected by optical crosstalk from a wider range of sub-pixels than the sub-pixel of the other image. In addition, when one image is displayed in a direction greatly deviated from the front to the left or right, the brightness of the displayed image decreases as the image is deviated from the front, so that the influence of optical crosstalk is relatively visible. Thus, the sub-pixel of one image is affected by optical crosstalk from a wider range of sub-pixels than the sub-pixel of the other image. For example, the influence of crosstalk from surrounding pixels can be ignored for the other image, but the influence of crosstalk from surrounding pixels cannot be ignored for one image. In such a case, for one image, the crosstalk is more difficult to be visually recognized by correcting the optical crosstalk using the gradation values of the sub-pixels included in the surrounding pixels as well as the adjacent pixels. Is possible.

  As described above, in one aspect, the crosstalk correction unit 191 performs the correction when the gradation value of the sub-pixel to be corrected is corrected using the gradation values of the sub-pixels around the sub-pixel. The sub-pixel used for the correction is changed according to the direction in which the sub-pixel to be corrected is displayed. Specifically, the crosstalk correction unit 191 performs correction using the gradation values of the subpixels at different positions or ranges with respect to the subpixels depending on the direction in which the subpixels to be corrected are displayed. For example, if the range of subpixels that affect crosstalk on the subpixels of the first image is wider than the range of subpixels that affect crosstalk on the subpixels of the second image, When correcting the gradation value of the sub-pixel of the first image, the talk correcting unit 191 sets the gradation value of the sub-pixel in a wider range than when correcting the gradation value of the sub-pixel of the second image. Used for correction. For example, the crosstalk correction unit 191 uses only the sub-pixel of the adjacent pixel for correcting the gradation value of the sub-pixel of the second image, and uses the adjacent pixel for correction of the gradation value of the sub-pixel of the first image. And subpixels of surrounding pixels are used.

  In this aspect, for example, when the sub-pixel selection unit 111 selects a gradation value of a sub-pixel that has an effect of crosstalk, the sub-pixel selection unit 111 changes the selection depending on the display direction of the sub-pixel to be corrected. Specifically, the sub-pixel selection unit 111 selects the gradation values of sub-pixels at different positions or ranges with respect to the correction-sub-pixels depending on the display direction of the correction-sub-pixels.

  Further, in this aspect, the left-direction optical crosstalk correction value generation unit 240 and the right-direction optical crosstalk correction value generation unit 241 each have a number of LUTs corresponding to the supplied gradation values. Different numbers of LUTs may be included. When the gradation value of the sub-pixel displayed in the left direction is a correction target, the supply of the gradation value to the right-side optical crosstalk correction value generation unit 241 is insufficient or excessive with respect to the LUT. There is a case. In this case, the optical crosstalk correction value generation unit 241 for the right direction corrects, for example, by ignoring excessive gradation values or using a predetermined value instead of the insufficient gradation value. A value can be generated. Similarly, when the gradation value of the sub-pixel displayed in the right direction is a correction target, the left-side optical crosstalk correction value generation unit 240 ignores an excessive gradation value or an insufficient gradation value. A correction value can be generated by supplementing the value with a predetermined value.

  FIG. 26 is a flowchart showing the processing of the sub-pixel selecting unit 111 when changing the selection of the gradation value of the sub-pixel having the influence of the crosstalk depending on the display direction. This process is executed, for example, in step S251 in FIG. FIG. 26 illustrates processing when the sub-pixel displayed in the right direction is affected by optical crosstalk from a wider range of sub-pixels than the sub-pixel displayed in the left direction. ing.

  The sub-pixel selection unit 111 acquires the display direction of the correction target sub-pixel (S261). In this case, similarly to the correction value selector 242 described above, the sub pixel selection unit 111 counts up the coordinate counter together with the output of the gradation value of the correction target sub pixel, and the display direction of the correction target sub pixel is displayed. It is possible to know.

  Next, the sub-pixel selection unit 111 determines whether the display direction acquired in step S261 is the left direction or the right direction (S262).

  If it is determined that the direction is the left direction (S262: left direction), the sub pixel selection unit 111 selects the gradation value of the sub pixel included in the adjacent pixel of the pixel including the correction target sub pixel, The gradation values of the sub-pixels used for correction are output to the left optical crosstalk correction value generator 240 and the right optical crosstalk correction value generator 241 (S263). For example, when the G subpixel in the R direction at the coordinate (x, y) in FIG. 9 is the correction target, the subpixel selection unit 111 is adjacent to the pixel at the coordinate (x, y) shown in FIG. The gradation values of a total of four subpixels of the same G color as the subpixels displayed in the L direction different from the subpixels included in the pixel are selected and output.

  On the other hand, when it is determined to be rightward (S262: rightward), the sub-pixel selection unit 111 sets the gradation value of the sub-pixel included in the adjacent pixel and the surrounding pixel including the correction target sub-pixel. This is selected and output to the left-direction optical crosstalk correction value generation unit 240 and the right-direction optical crosstalk correction value generation unit 241 as gradation values of the sub-pixels used for correction (S264). For example, when the G subpixel in the R direction at the coordinate (x, y) in FIG. 9 is the correction target, the subpixel selection unit 111 is adjacent to the pixel at the coordinate (x, y) shown in FIG. The gradation values of a total of 12 sub-pixels of the same G color as the sub-pixels displayed in the L direction different from the sub-pixels included in the pixels and surrounding pixels are selected and output.

  As described above, in the present embodiment, the crosstalk correction unit changes the correction amount for the gradation value of the correction target sub-pixel according to the direction in which the sub-pixel is displayed. Therefore, according to the present embodiment, even when the occurrence of crosstalk varies depending on the image display direction, crosstalk correction suitable for each direction can be performed, and crosstalk is less likely to be visually recognized. Can do. For example, even when the display unit displays the first and second images in different asymmetric directions, appropriate crosstalk correction can be performed in each direction. Specifically, in a direction-specific image or stereoscopic image display device that displays a plurality of images in different directions on the same display screen, depending on circumstances such as the installation position of the device and the position where the viewer views the display screen, the display device In some cases, it is desired to display each image in an asymmetrical direction. In such a case, it is necessary to align one or both of the liquid crystal display device and the parallax optical element in an asymmetric direction, and as a result, the state of occurrence of crosstalk may differ depending on the display direction of each image. According to the present embodiment, even in such a case, crosstalk correction suitable for each direction can be performed, and crosstalk can be made difficult to be visually recognized.

  Further, the crosstalk correction unit corrects the gradation value of the correction target sub-pixel using a correction value corresponding to the gradation value of the sub-pixels around the sub-pixel, and the correction target sub-pixel is displayed. The correction value is changed according to the direction in which it is to be moved. According to this aspect, when the magnitude of the influence of crosstalk from surrounding subpixels on the subpixel to be corrected differs depending on the display direction of the image, crosstalk correction suitable for each direction can be performed.

  Further, the crosstalk correction unit corrects the gradation value of the correction target sub-pixel using the gradation values of the sub-pixels around the sub-pixel, and the above-described correction target sub-pixel is displayed according to the direction in which the correction target sub-pixel is displayed. The subpixel used for correction is changed. According to this aspect, when the position and range of the sub-pixel that affects the cross-talk with respect to the sub-pixel to be corrected differ depending on the display direction of the image, cross-talk correction suitable for each direction can be performed. .

  In the above description, the configuration in which the correction amount of the optical crosstalk correction is mainly changed according to the display direction of the sub-pixel to be corrected has been described. However, the cross-talk correction unit displays the display direction of the sub-pixel to be corrected. Thus, the correction amount of the electrical crosstalk correction may be changed. For example, in the example of FIG. 24, only the optical crosstalk correction value generation unit is divided into those for the left direction display sub-pixel and those for the right direction display sub-pixel. When the influence of the crosstalk is also asymmetrical, the electrical crosstalk correction value generation unit 113 may be similarly divided according to direction.

  In the above description, after generating both the left correction value and the right correction value, one of the left correction value and the right correction value is selected and used according to the display direction of the correction target sub-pixel. However, it may be configured to generate and use only one of the left correction value and the right correction value in accordance with the display direction of the correction target sub-pixel. For example, when a sub-pixel displayed in the left direction is a correction target, the gradation value is supplied from the sub-pixel selection unit 111 to the optical crosstalk correction value generation unit 241 for the right direction, or the optical for the right direction is used. The generation of the right correction value by the target crosstalk correction value generation unit 241 may be omitted.

Further, in an aspect in which the number of gradation values of sub-pixels used for correction differs depending on the display direction of the correction target sub-pixel, the average of the gradation values of several sub-pixels having the larger number is calculated. It is possible to reduce the number of gradation values of the sub-pixels used for correction and to align the number of gradation values of the sub-pixels used for correction in the display direction. By doing so, it is possible to reduce the number of LUTs for calculating correction values and to align the number of LUTs between display directions.
Further, the configuration of the fifth embodiment may be combined with the configurations of the second to fourth embodiments.

  In the first to fifth embodiments described above, the image processing apparatus of the present invention is realized by a crosstalk correction unit. However, the image processing device may include a portion other than the crosstalk correction unit in the image display device. The function of the image processing apparatus is realized by a hardware circuit in one aspect, but may be realized by cooperation of hardware resources and software. Specifically, the functions of the image processing apparatus may be realized by executing an image processing program by a computer. More specifically, the function of the image processing apparatus is such that an image processing program recorded on a recording medium such as a ROM (Read Only Memory) is read out to a main storage device, and is executed by a central processing unit (CPU). It may be realized by being executed. The image processing program may be provided by being recorded on a computer-readable recording medium such as an optical disk, or may be provided via a communication line such as the Internet.

  DESCRIPTION OF SYMBOLS 1 Input terminal 2,140,151,171,191 Crosstalk correction | amendment part, 3 gradation conversion part, 4 timing signal generation part, 5,192 display part, 21 backlight, 22 liquid crystal panel, 23,213 parallax barrier, 100, 150, 170, 190 Image display device, 111 sub-pixel selection unit, 112 correction unit, 113 electrical crosstalk correction value generation unit, 113-1 to 113-4 LUT for electrical crosstalk correction, 114 optical cross Talk correction value generation unit, 114-1 to 114-12 optical crosstalk correction LUT, 115 correction value addition unit, 141 electro / optical crosstalk correction value generation unit, 141-1 to 141-2 electro / optical LUT for crosstalk correction, 152 temperature sensor, 153 A / D converter, 61 LUT data storage unit, 162 LUT control unit, 172 average luminance calculation unit, 173 backlight adjustment signal generation unit, 180 correction value adjustment unit, 240 left direction optical crosstalk correction value generation unit, 240-1 to 240- 12 LUT for optical crosstalk correction for left direction, 241 Optical crosstalk correction value generation unit for right direction, 241-1 to 241-12 LUT for optical crosstalk correction for right direction, 242 Correction value selector.

Claims (2)

An image obtained by combining a first image displayed in a first direction and a second image displayed in a second direction different from the first direction, and corresponding to each of a plurality of colors A plurality of pixels including the above subpixels are arranged, and the gradation of each subpixel of the image in which the subpixels constituting the first image and the subpixels constituting the second image are alternately arranged An image signal representing a value is received as an input image signal, and gradation values of sub-pixels of the input image signal are set so as to make the influence of crosstalk between the first image and the second image less visible by correction. A crosstalk correction unit for correcting and outputting as an image signal after crosstalk correction;
A display unit having a display surface for displaying the first image in the first direction and displaying the second image in the second direction based on the image signal after the crosstalk correction;
The angle formed between the first direction and the front direction of the display surface is smaller than the angle formed between the second direction and the front direction of the display surface,
The crosstalk correction unit includes a sub-pixel selection unit and a correction unit,
The sub-pixel selector is
In a case where the display direction of the correction target sub-pixel is the first direction, a plurality of pixels surrounding and adjacent to the pixel including the correction target sub-pixel are defined as the adjacent pixel group. Of the sub-pixels included in the pixel group, the gradation value of the sub-pixel displayed in the second direction and having the same color as the correction target sub-pixel is selected.
When the display direction of the correction target sub-pixel is the second direction, a plurality of pixels surrounding the adjacent pixel group are included in the adjacent pixel group and the peripheral pixel group. Among the sub-pixels to be displayed, the gradation values of the sub-pixels displayed in the first direction and having the same color as the sub-pixel to be corrected are selected, and the gradation of each sub-pixel selected by the sub-pixel selection unit Calculating an average value or a weighted addition value of gradation values of sub-pixels in a direction close to the sub-pixel to be corrected among the values as an added gradation value;
The correction unit corrects a gradation value corresponding to the gradation value of each of the sub-pixels to cancel a gradation value shift caused by the influence of crosstalk that the added gradation value has on the correction target sub-pixel. An image display device, wherein a gradation value of the correction target sub-pixel is corrected using the correction value. The image display according to claim 1, wherein the correction unit corrects the gradation value of the correction target sub-pixel by adding the correction value and the gradation value of the correction-target sub-pixel. apparatus.

Images