JP2017173667A - Image display device and image display method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the deterioration in synthesis image caused by the displacement between two LCD panels for improving the contrast ratio, compensate the decrease in yield, and reduce the cost.SOLUTION: An image display device includes: an RGB controller (10) that generates an RGB image signal to be displayed in a front-side LCD panel (1); an LV controller (20) that generates a first gray image signal to be displayed on a rear-side LCD panel (2); and a shift and rotation correction unit that includes a storage unit storing the shift amount corresponding to the displacement amount in the horizontal and vertical directions and the rotation amount corresponding to the displacement amount in the rotation direction as the amount of displacement in a panel attaching step, generates a second gray image signal by correcting the display position coordinate on the basis of the shift amount and the rotation amount with respect to the first gray image signal, and supplies the second gray image signal to the rear-side LCD panel.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image display apparatus and an image display method for improving the contrast ratio using two LCD panels.

  In a conventional image display device using a single LCD panel, the input image is corrected by a polygonal line gamma with a panel driver, thereby realizing a linearity characteristic of the visual gradation.

  However, in reality, the luminance is expressed by the backlight illumination passing through the liquid crystal panel, so the gradation characteristics in the black region are particularly bad, and the luminance is observed in the brighter direction than the ideal luminance. The so-called black floating phenomenon occurs.

  This phenomenon occurs because when the LCD panel displays a dark region, the light shielding of the LCD panel is not complete and the backlight illumination light leaks. A conventional CRT has a contrast ratio of about 10,000: 1, and an organic EL panel has a contrast ratio of about 1,000,000: 1. However, due to this phenomenon, in a conventional image display device using a single LCD panel, a contrast ratio of only about 1500: 1 can be realized.

  Thus, in order to improve the contrast ratio of such a single LCD image display device, an image display device using two LCDs has been proposed (see, for example, Patent Documents 1 and 2). Each of the image display devices is configured to use two LCDs, and the contrast ratio is improved by adjusting the backlight transmission amount on the rear LCD and performing RGB display on the front LCD.

JP-A-5-88197 International Publication No. 2007/108183

However, the prior art has the following problems.
As described above, an image display device using a single LCD panel has a problem that a contrast ratio of only about 1500: 1 can be realized. Furthermore, one LCD has a major problem that faithful reproduction of an image cannot be realized due to a decrease in color reproducibility in a dark image or a deterioration in black quality.

  On the other hand, an image display device using two LCD panels as in Patent Documents 1 and 2 has an effect of improving contrast and preventing black float. However, such an image display device using two LCD panels has a problem that a positional shift occurs in the process of bonding the two LCD panels. This problem will be described below with reference to the drawings.

  FIG. 10 is a diagram for explaining a general image display device using two LCD panels. In FIG. 10, the back-side backlight-side LCD panel is referred to as an LV panel 2 (Light Valve Panel), and the front-side LCD panel that is close to a person viewing an image is referred to as an RGB panel 1.

  As shown in FIG. 10, the RGB panel 1 and the LV panel 2 are bonded to each other via the light diffusion layer 3. Here, the RGB panel 1 is composed of R, G, and B sub-pixels. On the other hand, the LV panel 2 combines R, G, and B sub-pixels into one pixel. That is, one pixel of the LV panel 2 is common to one pixel in which the sub-pixels of the RGB panel 1 are combined, and has a 1: 1 correspondence.

  Then, the RGB panel 1 and the LV panel 2 are attached to the front and back, and the backlight is illuminated from the LV panel 2 side, thereby improving the contrast ratio by multiplying the light transmittance of the rear and front panels. ing.

  However, when the RGB panel 1 and the LV panel 2 are bonded to each other, if a relative positional shift occurs between the two panels, there arises a problem that the compositely displayed image (synthesized image) is blurred. FIG. 11 is a diagram for explaining a problem of misalignment in a conventional image display apparatus. As shown in FIG. 11, as a result of bonding the RGB panel 1 and the LV panel 2 including an alignment error, the synthesized image which is intended to improve the contrast ratio is blurred.

  A direct bonding process is required to bond the two LCD panels. However, in this manufacturing process, it is difficult to guarantee physical positional accuracy, and there is a risk that image blurring will occur. Further, in order to perform the bonding with the alignment error within an allowable value, a very expensive manufacturing apparatus is required.

  The present invention has been made to solve the above-described problems. When two LCD panels are used to improve the contrast ratio, the deterioration of the composite image due to the misalignment of bonding is performed. It is an object of the present invention to obtain an image display apparatus and an image display method capable of suppressing the above-described problem and reducing the yield and reducing the cost.

  An image display device according to the present invention is configured by stacking two front side LCD panels and a rear side LCD panel, and displays an image by transmitting backlight in order of the rear side LCD panel and the front side LCD panel. An RGB controller that generates an RGB image signal after performing a first process for displaying the input RGB image signal on the front LCD panel, and the input RGB image signal By the bonding process of the LV controller that generates the first gray image signal after performing the second process for displaying the image signal on the rear LCD panel, and the front LCD panel and the rear LCD panel As the amount of displacement, a shift amount corresponding to the amount of displacement in the horizontal and vertical directions of the rear LCD panel relative to the front LCD panel, and the front side L There is a storage unit in which a rotation amount corresponding to the amount of shift in the rotation direction of the rear LCD panel with respect to the D panel is stored in advance, and the first gray image signal generated by the LV controller depends on the shift amount and the rotation amount. A shift / rotation correction unit that generates a second gray image signal by performing display position coordinate correction, and supplies the second gray image signal to the rear LCD panel to compensate for a positional shift amount generated in the bonding process; It is to be prepared.

  In addition, the image display method according to the present invention is configured by stacking two front side LCD panels and two rear side LCD panels, and backlight light passes through the rear side LCD panel and the front side LCD panel in this order. An image display method for displaying an image, wherein a plurality of marker positions on the front LCD panel and a plurality of marker positions on the rear LCD panel are imaged by a camera after the bonding process between the front LCD panel and the rear LCD panel. The rear side LCD with respect to the front side LCD panel as a positional deviation amount in the bonding process from the first step and the plurality of marker positions of the front side LCD panel and the plurality of marker positions of the rear side LCD panel acquired in the first step. The amount of shift corresponding to the horizontal and vertical displacement of the panel, and the rear side L with respect to the front side LCD panel A second step of calculating a rotation amount corresponding to a shift amount of the rotation direction of the D panel and storing it in the storage unit, and a first process for displaying the input RGB image signal on the front LCD panel. A third step of generating an RGB image signal after application, and a first gray image signal after performing a second process for displaying the input RGB image signal on the rear LCD panel. The second gray image signal is generated by performing display position coordinate correction on the first gray image signal generated in the fourth step and the fourth step by the shift amount and the rotation amount stored in the storage unit, And supplying a 2-gray image signal to the rear LCD panel to compensate for the amount of misalignment caused in the bonding process.

  According to the present invention, there is provided a configuration in which a positional shift that occurs in the process of bonding two LCD panels is corrected in the display stage by signal processing on the LV panel side. As a result, when two LCD panels are used to improve the contrast ratio, the deterioration of the composite image due to the misalignment of the bonding can be suppressed, and the yield can be compensated and the cost can be reduced. A display device and an image display method can be obtained.

It is a signal processing block diagram of the image display apparatus comprised by bonding together two LCD panels. It is a figure which shows the whole structure of the image display apparatus in Embodiment 1 of this invention. It is a flowchart of the arithmetic processing performed by PC in Embodiment 1 of this invention. It is the figure which showed the positional relationship of four markers detected by the marker detection part in Embodiment 1 of this invention. It is a figure for demonstrating the calculation process of the shift amount and rotation amount which are performed by the shift amount and rotation amount calculation part in Embodiment 1 of this invention. It is the figure which showed the internal structure of the shift / rotation correction | amendment part in Embodiment 1 of this invention. It is the figure which showed five images by the 1st simulation result in Embodiment 1 of this invention. It is the figure which showed five images by the 2nd simulation result in Embodiment 1 of this invention. It is the figure which showed two images by the 3rd simulation result in Embodiment 1 of this invention. It is a figure for demonstrating the general image display apparatus using two LCD panels. It is a figure for demonstrating the position shift problem in the conventional image display apparatus.

  Hereinafter, preferred embodiments of an image display device and an image display method of the present invention will be described with reference to the drawings.

  The present invention is an image that improves the contrast ratio due to the effect of multiplying the light transmittance of the rear and front panels by attaching two LCD panels back and forth and illuminating the backlight from the back side. The display device and the image processing method are technically characterized by having a configuration in which a positional deviation caused in a process of bonding two LCD panels is corrected in a display stage by signal processing on the LV panel side.

Embodiment 1 FIG.
First, a general configuration of a general liquid crystal display device in which two LCD panels are bonded will be described. FIG. 1 is a signal processing block diagram of an image display apparatus configured by bonding two LCD panels. The image display apparatus shown in FIG. 1 includes an RGB controller 10 and an LV controller 20.

  Here, the RGB controller 10 includes a bit expansion circuit 11, a delay circuit 12, a gradation conversion circuit 13, and a color balance controller 14, and an output from the color balance controller 14 is supplied to the RGB panel 1.

  The LV controller 20 includes a gray converter 21, a gradation conversion circuit 22, an edge hold circuit 23, and a low pass filter 24, and an output from the low pass filter 24 is supplied to the LV panel 2.

  Next, an outline of signal processing by the RGB controller 10 and the LV controller 20 will be described.

  For example, the bit extension circuit 11 performs a bit extension process to 12 bits on the input 10-bit RGB image. In this bit extension process, the bit length is extended with high accuracy in advance so as not to lower the bit precision in subsequent processing. The bit extension circuit 11 transmits the RGB image after bit extension to each of the delay circuit 12 and the gray converter 21.

  In the configuration shown in FIG. 1, the bit extension circuit 11 is provided in the RGB controller 10. However, the bit extension circuit 11 is provided outside the RGB controller 10, and the RGB image after bit extension is connected to the RGB controller 10. It is also possible to supply to the LV controller 20.

  Further, in order to prevent the bit accuracy from being lowered in the subsequent processing, it is possible to employ a configuration in which the bit expansion circuit 11 is eliminated when processing for extending the bit length with high accuracy in advance is not necessary.

  The delay circuit 12 in the RGB controller 10 receives the RGB image after bit extension from the bit extension circuit 11 and applies an appropriate delay to the received RGB image after bit extension. This “appropriate delay” is for compensating for the processing delay by the gray converter 21, the edge hold circuit 23, and the low-pass filter 24 in the LV controller 20.

  Next, the gradation conversion circuit 13 in the RGB controller 10 performs gradation conversion using an LUT (look-up table) for each delayed color.

  On the other hand, the gray converter 21 in the LV controller 20 receives the RGB image after bit extension from the bit extension circuit 11 and, for the received RGB image after bit extension, three values of RGB for each pixel. Is converted into a gray image with the maximum value in the image as a representative value.

  Usually, in the conversion to gray scale, luminance is often obtained by performing color matrix conversion using a multiplier and an adder. The gray converter 21 according to the first embodiment detects the maximum value of the R, G, and B values in each pixel so that the color balance controller 14 in the RGB controller 10 can easily perform RGB color balance correction. However, by outputting this as a representative value, the hardware is also simplified.

  Of course, it is needless to say that the color balance correction process can be executed without any problem even when the normal matrix conversion is adopted.

  Next, the gradation conversion circuit 22 in the LV controller 20 performs gradation conversion on the gray image using the LUT. Next, the edge hold circuit 23 in the LV controller 20 performs viewing angle correction on the gray image after gradation conversion, and generates a gray image (B / W image).

  Further, the low-pass filter 24 in the LV controller 20 performs a process of smoothing the edge portion by performing a filter process on the gray image after the viewing angle correction by the edge hold circuit 23.

  The gray image processed by the low-pass filter 24 is displayed on the LV panel 2 and transmitted to the color balance controller 14 in the RGB controller 10. The color balance controller 14 in the RGB controller 10 corrects the color balance based on the signal after gradation conversion by the gradation conversion circuit 13 and the gray image after processing by the low-pass filter 24, and the corrected color balance controller 14 An RGB image is displayed on the RGB panel 1.

  Next, an image having a configuration for realizing the technical feature of the present invention “correcting a positional shift caused in a process of bonding two LCD panels at the display stage by signal processing on the LV panel side”. The display device will be described in detail with reference to the drawings.

  FIG. 2 is a diagram showing an overall configuration of the image display apparatus according to Embodiment 1 of the present invention. The image processing apparatus according to the first embodiment shown in FIG. 2 further includes a shift / rotation correction unit 30 provided at the subsequent stage of the LV controller 20 with respect to the configuration of FIG. The shift / rotation correction unit 30 has a signal processing function for correcting a positional shift generated in the process of bonding the RGB panel 1 and the LV panel 2 at a display stage on the LV panel 2 side.

  In order to realize this signal processing function by the shift / rotation correction unit 30, it is necessary to quantitatively calculate the displacement amount after the RGB panel 1 and the LV panel 2 are bonded together as the shift amount and the rotation amount. is there. For this purpose, in the configuration of FIG. 2, a PC (personal computer) 40 and a camera 50 are used.

  The camera 50 photographs the position of the marker 4 provided for alignment on each panel after the two LCD panels are bonded together in the panel manufacturing process. And the image imaged with the camera 50 is taken in by PC40, and the calculation process of shift amount and rotation amount is performed.

  The PC 40 has a marker detection unit 41 having an arithmetic processing mechanism for calculating the position of the marker 4 based on the input image, and an arithmetic processing mechanism for calculating the shift amount and the rotation amount based on the calculated position of the marker 4. A shift amount / rotation amount calculation unit 42 is provided.

  Next, specific calculation processing by the marker detection unit 41 and the shift amount / rotation amount calculation unit 42 will be described in detail with reference to the flowchart of FIG. 3 and the explanatory diagrams of FIGS. 4 and 5. FIG. 3 is a flowchart of arithmetic processing executed by the PC 40 in the first embodiment of the present invention.

  First, in step S301, the marker detection unit 41 in the PC 40 captures an image captured by the camera 50. This image includes two or more markers 4 on each panel after the RGB panel 1 and the LV panel 2 are bonded together.

  In the following, in order to simplify the description, the positions of the two markers 4 on the RGB panel 1 are P0 and P1, the positions of the two markers 4 on the LV panel 2 are P2 and P3, and the four points are The case where the shift amount and the rotation amount are calculated will be described. Note that, when the four markers are pasted together with no positional deviation, the positions of P0 and P2 match and the positions of P1 and P3 match.

Next, in step S302, the marker detection unit 41 detects the position coordinates on the XY plane of each marker 4 of each panel as the following values.
P0 (x0, y0)
P1 (x1, y1)
P2 (x2, y2)
P3 (x3, y3)

  In the following, in order to simplify the description, P0 is a coordinate origin (0, 0), and the remaining P1, P2, and P3 are positions where P0 is a coordinate origin. FIG. 4 is a diagram showing the positional relationship between the four markers detected by the marker detection unit 41 according to Embodiment 1 of the present invention. The positional relationship between P1 and P3 when P0 is the origin is shown, and the marker detection unit 41 detects the position coordinates of four points as shown in FIG.

  Next, in step S303, the shift amount / rotation amount calculation unit 42 calculates a shift amount and a rotation amount for causing P2 to coincide with P0 and P3 to coincide with P1. FIG. 5 is a diagram for explaining the shift amount and rotation amount calculation processing executed by the shift amount / rotation amount calculation unit 42 according to Embodiment 1 of the present invention.

  If the coordinates after P2 (x2, y2) is moved to a position coincident with P0 (0, 0) is P2 ′ (x2 ′, y2 ′), the shift amount at that time is apparent from FIG. And (−x2, −y2).

If the coordinates after shifting P3 (x3, y3) by the same amount as (−x2, −y2) are P3 ′ (x3 ′, y3 ′), the coordinates of P3 ′ are
x3 '= x3-x2
y3 '= y3-y2
Calculated by

That is, the shift amount / rotation amount calculation unit 42 determines the shift amount based on the coordinate value of P2 as shift amount: (−x2, −y2).
Can be calculated as

  Next, the angle θ between the line segment P0-P1 and the line segment P2'-P3 'has the relationship of the following expression (1) from the inner product expression.

  Therefore, the rotation amount θ is calculated as the following equation (2).

  That is, the shift amount / rotation amount calculation unit 42 can calculate the rotation amount as the above equation (2) based on the coordinate values of P1, P2, and P3.

  In step S304, the shift amount / rotation amount calculation unit 42 outputs the calculated shift amount and rotation amount, and the shift / rotation correction unit 30 outputs the shift amount and rotation amount calculated by the shift amount / rotation amount calculation unit 42. By using the amount of rotation as a parameter and performing signal processing on the LV panel side, it is possible to compensate for misalignment caused in the process of bonding two LCD panels.

  Next, a detailed configuration of the shift / rotation correction unit 30 will be described with reference to the drawings. FIG. 6 is a diagram showing an internal configuration of the shift / rotation correction unit 30 according to the first embodiment of the present invention. The shift / rotation correction unit 30 illustrated in FIG. 6 includes a parameter memory 31, an address controller 32, an input memory 33, and a rotation coordinate conversion unit 34.

  The parameter memory 31 is a memory for storing the shift amount calculated by the PC 40 and the rotation amount. Here, in the following description, the shift amount set in the parameter memory 31 is (−a, −b), and the rotation amount is θ.

  On the other hand, the input memory 33 is a memory for storing image data output from the LV controller 20. Then, the address controller 32 shifts the image data stored in the input memory 33 according to the shift amount (−a, −b) stored in the parameter memory 31. This shift amount correction corresponds to shift correction so that P2 and P3 coincide with P2 'and P3', respectively, as described above with reference to FIG.

  Further, the rotation coordinate conversion unit 34 corrects the rotation amount for the image data after the shift amount is corrected in accordance with the rotation amount θ stored in the parameter memory 31. As described with reference to FIG. 5, the correction of the rotation amount corresponds to the rotation correction so that P3 'matches P1.

  Then, the rotation coordinate conversion unit 34 supplies the image data after the rotation correction to the LV panel 2. As a result, the signal processing of the image data displayed on the LV panel 2 side can eliminate the positional deviation between the image data displayed on the RGB panel 1 and the image data displayed on the LV panel 2 side. It is possible to display a composite image.

  In the configuration shown in FIG. 6, the correction of the shift amount (parallel movement) and the correction of the rotation amount (rotation movement) are individually performed, but the coordinate value of the image before correction is (x, y), When the coordinate value of the image after correcting the shift amount θ and the rotation amount (−a, −b) is (x ′, y ′), the shift amount and the rotation amount are obtained by performing the rotation coordinate conversion of the following expression. It can also be corrected at the same time.

  Next, a simulation result using the sample image will be described. FIG. 7 is a diagram showing five images according to the first simulation result in the first embodiment of the present invention. Specifically, in this first simulation, the improvement effect of the composite image was verified when the LV panel 2 was bonded to the RGB panel 1 with 10 pixels shifted in the horizontal and vertical directions. Is.

Each of the five images corresponds to an image having the following contents.
Image (7-1): Original image input to display device according to Embodiment 1 Image (7-2): RBG image output from RGB controller 10 Image (7-3): From LV controller 20 Output LV image Image (7-4): A composite image obtained from the image (7-2) and the image (7-3) without being corrected by the shift / rotation correction unit 30, and the original image Image (7-5): A composite image obtained from the image (7-2) and the image (7-3) and the original image after being corrected by the shift / rotation correction unit 30

  From the result of the first simulation, it is understood that the composite image is improved by shift-correcting the image data to be displayed on the LV panel 2 side in consideration of a shift of 10 pixels as the shift amount.

  Next, FIG. 8 is a diagram showing five images according to the second simulation result in the first embodiment of the present invention. Specifically, in this second simulation, the improvement effect of the composite image when the LV panel 2 is bonded to the RGB panel 1 in a state of being rotated by 10 ° in the rotation direction is verified.

Each of the five images corresponds to an image having the following contents.
Image (8-1): Original image input to the display device according to the first embodiment Image (8-2): RBG image output from the RGB controller 10 Image (8-3): From the LV controller 20 Output LV image Image (8-4): A composite image obtained from the image (8-2) and the image (8-3) without being corrected by the shift / rotation correction unit 30, and the original image Image (8-5): Comparing the composite image obtained from the image (8-2) and the image (8-3) with the original image after correction by the shift / rotation correction unit 30

  From the result of the second simulation, it can be seen that the composite image is improved by rotationally correcting the image data to be displayed on the LV panel 2 side in consideration of a shift of 10 ° as the rotation amount.

  Next, FIG. 9 is a diagram showing two images according to the third simulation result in the first embodiment of the present invention. Specifically, in the third simulation, the LV panel 2 is bonded to the RGB panel 1 while being shifted by 10 pixels in the horizontal and vertical directions and rotated by 10 ° in the rotation direction. In this case, the improvement effect of the composite image is verified.

Each of the two images corresponds to an image having the following contents.
Image (8-4): Composite image obtained from RGB image and LV image without correction by shift / rotation correction unit 30 Image (8-5): RGB after correction by shift / rotation correction unit 30 Composite image obtained from image and LV image

  From the result of the third simulation, image data to be displayed on the LV panel 2 side is subjected to shift / rotation correction in consideration of a shift of 10 pixels as a shift amount and a shift of 10 ° as a rotation amount. By doing so, it can be seen that the composite image is improved.

  When the shift correction and the rotation correction are performed on the LV image, the image at the end of the screen of the RGB panel 1 is the corrected image of the LV panel 2 according to the shift amount and the rotation amount. There is a risk that an area that does not overlap with the area may appear. In view of this, in consideration of the maximum shift amount and rotation amount that can occur in the manufacturing process, it is conceivable to manufacture the LV panel by increasing it by a plurality of pixels vertically and horizontally.

  In this way, the display area of the LV panel 2 is secured several pixels larger in the vertical and horizontal directions than the display area of the RGB panel 1, so that even after the image data to be displayed on the LV panel 2 side is corrected for shift and rotation, A composite image can be obtained in all areas of the image.

  Further, in the above-described first embodiment, the case where the shift amount and the rotation amount are obtained from the two marker positions for each panel has been described. However, according to the present invention, it is also possible to obtain the shift amount and the rotation amount from three or more marker positions for each panel. In this case, the correction accuracy can be further improved.

  As described above, according to the first embodiment, after manufacturing two LCD panels, the positional deviation amount of bonding is obtained, and the LV image subjected to the shift / rotation correction so as to cancel the positional deviation amount is obtained. A configuration for displaying on the LV panel side is provided. As a result, when two LCD panels are used to improve the contrast ratio, it is possible to suppress deterioration of the composite image due to the misalignment of bonding, and to compensate for yield reduction and cost reduction.

  Further, by manufacturing the LV panel so that the number of pixels of the LV panel is several pixels larger in the vertical and horizontal directions than the number of pixels in the RGB panel, the bonding position is shifted over the entire display area of the RGB panel. It is possible to suppress the deterioration of the resulting composite image.

  Further, although not described in the first embodiment, it is conceivable to use an interpolation calculation by a filter when implementing a parallel movement of one pixel or less.

  1 RGB panel, 2 LV panel, 3 light diffusion layer, 4 marker, 10 RGB controller, 11 bit extension circuit, 12 delay circuit, 13 gradation conversion circuit, 14 color balance controller, 20 LV controller, 21 gray converter, 22 floor Tone conversion circuit, 23 edge hold circuit, 24 low-pass filter, 30 shift / rotation correction unit, 31 parameter memory, 32 address controller, 33 input memory, 34 rotation coordinate conversion unit, 41 marker detection unit, 42 shift amount / rotation amount calculation Part, 50 cameras.

Claims (5)

The image display device is configured by stacking two front side LCD panels and two rear side LCD panels, and performs image display by transmitting backlight light in the order of the rear side LCD panel and the front side LCD panel. And
An RGB controller that generates an RGB image signal after performing a first process for displaying the input RGB image signal on the front LCD panel;
An LV controller that generates a first gray image signal after performing a second process for displaying the input RGB image signal on the rear LCD panel;
As a positional shift amount due to a bonding process between the front LCD panel and the rear LCD panel, a shift amount corresponding to a horizontal and vertical shift amount of the rear LCD panel with respect to the front LCD panel, and the front LCD A storage unit in which a rotation amount corresponding to a shift amount of the rear LCD panel relative to the panel is stored in advance, and the shift amount and the first gray image signal generated by the LV controller The display position coordinates are corrected by the rotation amount to generate a second gray image signal, and the second gray image signal is supplied to the rear LCD panel to compensate for the displacement amount generated in the bonding step. An image display device comprising: a shift / rotation correction unit. The shift / rotation correction unit
A parameter memory for storing the shift amount and the rotation amount;
A first coordinate conversion unit that performs shift correction on the first gray image signal based on the shift amount stored in the parameter memory;
Based on the rotation amount stored in the parameter memory, second coordinates for performing rotation correction on the first gray image signal after the shift correction by the first coordinate conversion unit to generate the second gray image signal The image display device according to claim 1, further comprising: a conversion unit. The shift / rotation correction unit
A parameter memory for storing the shift amount and the rotation amount;
The shift amount in the horizontal and vertical directions is (−a, −b), the rotation amount in the rotation direction is θ, the coordinate value of the first gray image signal is (x, y), and the second When the coordinate value of the gray image signal is (x ′, y ′), the following formula

The image display apparatus according to claim 1, further comprising: a coordinate conversion unit configured to simultaneously perform shift correction based on the shift amount and rotation correction based on the rotation amount by performing coordinate conversion using The rear LCD panel is configured to have a larger number of pixels than the front LCD panel in order to display the entire image by the second gray image signal after the display position coordinate correction. Item 4. The image display device according to any one of Items 1 to 3. This is an image display method in which a front LCD panel and a rear LCD panel are overlapped, and an image is displayed by transmitting backlight light in the order of the rear LCD panel and the front LCD panel. And
A first step of imaging a plurality of marker positions of the front side LCD panel and a plurality of marker positions of the rear side LCD panel with a camera after the bonding step of the front side LCD panel and the rear side LCD panel;
From the plurality of marker positions of the front side LCD panel and the plurality of marker positions of the rear side LCD panel acquired in the first step, the positional deviation amount of the rear side LCD panel with respect to the front side LCD panel is calculated as the positional deviation amount by the bonding process. A second step of calculating a shift amount corresponding to a shift amount in the horizontal and vertical directions, and a rotation amount corresponding to a shift amount in the rotation direction of the rear LCD panel with respect to the front LCD panel, and storing the calculated amount in a storage unit;
A third step of generating an RGB image signal after performing a first process for displaying the input RGB image signal on the front LCD panel;
A fourth step of generating a first gray image signal after performing a second process for displaying the input RGB image signal on the rear LCD panel;
The display position coordinate correction is performed on the first gray image signal generated in the fourth step by the shift amount and the rotation amount stored in the storage unit to generate a second gray image signal, An image display method comprising: a fifth step of compensating for the amount of misalignment generated in the bonding step by supplying a second gray image signal to the rear LCD panel.

Images