JP2010197926A - Crosstalk correction table acquisition device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To separate correction data of electric crosstalk and correction data of optical crosstalk by RGB of subpixels to easily acquire an electric LUT and an optical LUT, and to further apply a separation method even when references of gradation for setting the correction data to zero are different. <P>SOLUTION: The crosstalk correction table acquisition device 10 acquires the electric correction table and the optical correction table of a liquid crystal display module which displays a first image and a second image in which subpixels are alternately adjacent so that they can be discriminated in different viewing direction, by light shielding of a slit. The acquisition device includes: an optical measuring instrument which measures optical characteristics of the first image displayed on the liquid crystal display panel when the subpixels for correction are in the first image; and a control part 14 which displays gradation of the subpixels of only one color out of gradation of three colors of RGB of the second image in an area of the liquid crystal panel to be measured by the optical measuring instrument at a value except a reference value. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to an electrical crosstalk correction table used in a liquid crystal display panel that displays a first image and a second image in which sub-pixels are alternately adjacent to each other in different viewing directions by light shielding of a slit, and an optical crosstalk correction table. The present invention relates to a crosstalk correction table acquisition device that acquires a crosstalk correction table.

The liquid crystal display panel is light, thin, and has low power consumption compared to a CRT (Cathode Ray Tube), and is therefore used in many electronic devices for display. The relationship between the input voltage and the luminance of the liquid crystal display panel is generally determined by assuming that the γ value is 2.2 and that the luminance is the input voltage due to the convenience of transmission of television broadcasts, the difference in characteristics with the CRT, and the characteristics of the human eye. Is displayed at a brightness of γ. The voltage applied to the liquid crystal display panel is a value according to the gradation,
An image is displayed with a predetermined gradation by controlling the twist amount of the liquid crystal molecules with an analog voltage. The number of gradation levels varies depending on the liquid crystal display panel. For example, there are 128 gradations, 64 gradations, 32 gradations, and the like, which are expressed by 7-bit, 6-bit, and 5-bit digital signals, respectively.

In a liquid crystal display panel, even when a voltage having a predetermined gradation is applied, if the gradation of adjacent subpixels is different, electrical crosstalk may occur, resulting in different brightness. The cause of this electrical crosstalk is that the spikes that occur as the scan line voltage switches,
This is considered to change the effective voltage value applied to the pixel. In particular, in a liquid crystal display panel for two-screen display developed for displaying a stereoscopic image or displaying different images in the driver's seat and the passenger seat, different images are input to adjacent sub-pixels. A lot of typical crosstalk occurs.

For this reason, a liquid crystal display device using a liquid crystal display panel applies a voltage subjected to electrical crosstalk correction to the liquid crystal display panel. This correction method is disclosed in Patent Document 1 below.
As described in the above, the designer previously obtained correction data of all combinations of each gradation of the subpixel to be corrected and each gradation of the adjacent subpixel through an experiment, and obtained an electrical correction table (hereinafter referred to as a “correction table” as an LUT). (Referred to as “Lookup Table”) and stored in the EEPROM of the liquid crystal display device. The liquid crystal display device reads the correction data corresponding to the gradation of the correction sub-pixel and the gradation of the adjacent sub-pixel from the electrical LUT, adds this to the correction sub-pixel gradation, and outputs the correction data to the liquid crystal display panel. I have to.

Further, in a two-screen liquid crystal display panel that displays different images in the first viewing direction and the second viewing direction in a distinguishable manner, a light shielding layer having a slit is used. Crosstalk also occurs. The cause of this optical crosstalk is due to light leakage caused by diffracting light from sub-pixels of the same color of adjacent pixels at the periphery of the slit of the light shielding layer. For this purpose, the designer determines the correction data of all the combinations of the gradations of the subpixel to be corrected and the gradations of the subpixels of the same color of the adjacent pixels in advance, creates an optical LUT, and creates the EEPROM of the liquid crystal display device. Remember it. The liquid crystal display reads the correction data corresponding to the gradation of the correction sub-pixel and the gradation of the sub-pixel of the same color of the adjacent pixel from the optical LUT, adds this to the gradation of the correction sub-pixel, and adds it to the liquid crystal display panel. Output.

JP 2008-20574 A

As described above, since the electrical crosstalk is corrected based on the gradation of the adjacent sub-pixel and the optical crosstalk is corrected based on the gradation of the sub-pixel of the same color of the adjacent pixel, the electrical LUT The optical LUT and the optical LUT had to be obtained experimentally as separate LUTs. However,
Since electrical crosstalk and optical crosstalk are generated in one subpixel, it is difficult to obtain each crosstalk amount separately for each subpixel RGB in an experiment. Therefore, there is a demand for a method of obtaining electrical crosstalk correction data and optical crosstalk correction data separately for each sub-pixel RGB.

In addition, the electrical LUT and the optical LUT have multiple types of LUTs depending on where the reference of gradation for setting correction data to 0 is used. For example, FIG. 9A shows a white reference electric LUT, and the correction data 0 is obtained when the gradation of the adjacent sub-pixel is 63 gradation of white. FIG. 9B shows a self-reference electric LUT, and correction data 0 is obtained when both gradations are equal. Furthermore,
FIG. 9C shows a black reference electric LUT, in which the correction data 0 is obtained when the gradation of the adjacent sub-pixel is 0 gradation of black. In this way, the liquid crystal display panel for two-screen display has multiple types of LUTs.
However, it is desirable to be able to apply a method for separating the same electrical crosstalk correction data and optical crosstalk correction data to any type of LUT.

The present invention has been made to solve such problems of the prior art. That is,
An object of the present invention is to separate electrical crosstalk correction data and optical crosstalk correction data into RGB sub-pixels to easily obtain an electrical LUT and an optical LUT. An object of the present invention is to provide a crosstalk correction table acquisition device that can apply the separation method even if the reference of the gradation for setting data to 0 is different.

In order to achieve the above object, the crosstalk correction table acquisition apparatus according to the present invention provides a first image and a second image in which three sub-pixels constituting one pixel of RGB are alternately adjacent to each other in different viewing directions due to light shielding of the slits. In order to correct the electrical crosstalk and the optical crosstalk generated in the liquid crystal display panel that can be displayed in a distinguishable manner, it is composed of correction data corresponding to the gradation of the subpixel to be corrected and the gradation of the adjacent subpixel. An electrical correction table and an optical correction table including correction data corresponding to sub-pixels of the same color of adjacent pixels as the gradation of the sub-pixel to be corrected are provided, and the correction of the electrical correction table is adjusted to the gradation of the sub-pixel of the correction target. The power of the crosstalk correction unit that performs crosstalk correction by adding the gradation based on the data and the gradation based on the correction data of the optical correction table. In the crosstalk correction table acquisition apparatus that acquires the correction table and the optical correction table, the reference value of the gradation for which the correction data is 0 is set to the gradation of the adjacent subpixel with respect to the gradation of each subpixel to be corrected. The electrical correction table, which is set to the gradation of the sub-pixel of the same color of the adjacent pixel, and the gradation is corrected so that an error from the optical characteristic when the optical characteristic of the sub-pixel to be corrected is the reference value is reduced, and In the optical correction table, when the correction target sub-pixel is the first image, an optical measuring instrument that measures optical characteristics of the first image displayed on the liquid crystal display panel, and the optical measuring instrument And a control unit that displays the gradation of only one of the three sub-pixels of RGB of the second image in the region of the liquid crystal display panel to be measured, other than the reference value. To.

According to the crosstalk correction table acquisition device of the present invention, the RGB of the second image is thus obtained.
By displaying the gradation of only one sub-pixel among the gradations of the sub-pixels of three colors other than the reference value, the correction data by the other two sub-pixels can be zero, so FIGS. As shown in FIG. 5, the sub-pixels of the first image having a color other than the reference value as the adjacent sub-pixel are electrically corrected, and the first color of the color having the same color other than the reference value as the sub-pixel of the adjacent pixel is corrected. The sub-pixels of one image are optically corrected, and the electrical crosstalk correction data and the optical crosstalk correction data can be separated by RGB of the subpixels. In addition, since the correction data is based on a reference value of 0, the present invention can be applied to multiple types of LUTs such as a self reference, a white reference, and a black reference.

In the crosstalk correction table acquisition apparatus of the present invention, the gradation of the subpixel to be corrected is i1, and the gradation of the subpixel of the same color as the gradation of the adjacent subpixel is i2.
When the correction data H1 (i1, i2) of the electrical correction table and the correction data H2 (i1, i2) of the optical correction table are acquired, the first in the region measured by the optical measuring instrument The first RGB when the gradation of all RGB sub-pixels of the image is i1, and the gradation of all the RGB sub-pixels of the second image is the reference value B (i1) corresponding to the gradation i1 of the first image. The luminance of the image is standard luminance k1 (i1), and the u′v ′ chromaticity coordinates of the first image at that time are standard u′v ′ chromaticity coordinates u ′ (i1) and v ′ (i1). A memory circuit for storing,
The control unit causes the gradation of all the RGB sub-pixels of the second image to be i2, and changes the gradation of all the sub-pixels of the first image with the same value h, whereby the luminance of the first image is increased. Correction data h that is the luminance of the first image closest to the standard luminance k1 (i1) is obtained, and this correction data h is obtained as correction data H1 (i1, i2) of the electrical correction table and correction data H2 ( i1 and i2), and the control unit 1 out of three RGB colors of the second image
The gradation of the color sub-pixel is set to i2, and the gradation of the remaining two-color sub-pixels is set to the reference value B (i1).
And the gradation of the sub-pixel of the first image in which the sub-pixel of the gradation i2 is an adjacent sub-pixel is h1.
By changing the gradation of the subpixel of the first image in which the subpixel of the gradation i2 is the same color subpixel of the adjacent pixel by changing h−h1 = h2, the u′v ′ color of the first image is changed. H1 and h2, which are the luminances of the first image whose degree coordinates are closest to the standard u′v ′ chromaticity coordinates u ′ (i1) and v ′ (i1), are obtained, and h1 is the correction data H1 of the electrical correction table. (I1, i2) and h2
Is preferably stored in the storage circuit as correction data H2 (i1, i2) of the optical correction table.

According to the crosstalk correction table acquisition apparatus of the present invention, the gradation is changed on the condition that the sum of the correction data of the electrical correction table and the correction data of the optical correction table is used, so the number of gradation changes is reduced and the efficiency is improved. The correction data of the electrical correction table and the correction data of the optical correction table can be acquired.

In the crosstalk correction table acquisition apparatus of the present invention, it is preferable that the reference value for setting the correction data to 0 is a gradation at which the adjacent subpixel and the same color subpixel of the adjacent pixel display white.

According to the crosstalk correction table acquisition apparatus of the present invention, since the LUT is based on white, the correction value is not negative. That is, since the minimum value of the correction value is 0, it is only necessary to obtain a correction value that provides optimum optical characteristics while starting the initial value of temporary correction from 0 and incrementing in an experiment.
On the other hand, since the correction value is both positive and negative according to its own standard, the minimum value of the correction value is undetermined. Therefore, when finding a correction value that provides optimal optical characteristics in an experiment, a very large provisional correction value must be set, or both increment and decrement must be performed. Time consuming. As described above, the correction table can be acquired in a short time by using the white reference. In addition, it is possible to widely correct a gradation of a portion having a low luminance where a difference in gradation is conspicuous as compared with the self-reference LUT. It should be noted that although there is a region that cannot be corrected slightly in a portion with high luminance, the luminance error becomes inconspicuous because the luminance is high.

In the crosstalk correction table acquisition apparatus of the present invention, the reference value for setting the correction data to 0 is the same for the gradation of the adjacent subpixel, the same color subpixel of the adjacent pixel, and the gradation of the subpixel to be corrected. A gradation is preferable.

According to the crosstalk correction table acquisition apparatus of the present invention, since the LUT is itself a reference,
Correction can be performed so that the contrast becomes high.

It is a block diagram which shows the outline | summary of the crosstalk correction table acquisition apparatus concerning this embodiment. It is a figure which shows the pixel arrangement | sequence of the liquid crystal display panel of FIG. FIG. 3A is a sectional view showing the principle of image separation of two screens, and FIG. 3B is a plan view showing a slit. It is a figure which shows composition of 2 screens. FIG. 5A is a table showing FRC correction data with 4 frames as one period, and FIG. 5B is a diagram showing an example of the sub-pixel arrangement. 6A is a diagram showing the occurrence of crosstalk, and FIG. 6B is a cross-sectional view showing the occurrence of crosstalk. It is a block diagram which shows the crosstalk correction | amendment part of the 2 screen display apparatus in which the liquid crystal display panel of FIG. 1 is integrated. FIG. 8A is a table showing the electrical LUT of FIG. 7, and FIG. 8B is a table showing the optical LUT of FIG. 9A is a diagram showing a white-reference electrical LUT, FIG. 9B is a diagram showing a self-reference electrical LUT, and FIG. 9C is a diagram showing a black-reference electrical LUT. It is a flowchart which shows the acquisition example of LUT. It is a flowchart which shows the detail of step S12 which is a subroutine of FIG. It is a flowchart which shows the detail of step S13 which is a subroutine of FIG. 13A is a diagram for supplementary explanation of step S21 in FIG. 11, and FIG. 13B is a diagram for supplementary explanation of step S31 in FIG. FIG. 14A is a self-reference diagram corresponding to FIG. 13A, and FIG. 14B is a self-reference diagram corresponding to FIG. 13B.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the embodiments and drawings. However, the embodiments shown below are not intended to limit the present invention to those described herein, and The invention can be equally applied to various modifications without departing from the technical idea shown in the claims. In each drawing used for the description in this specification, each layer and each member are displayed in different scales so that each layer and each member can be recognized on the drawing. However, it is not necessarily displayed in proportion to the actual dimensions.

The crosstalk correction table acquisition device 10 of this embodiment is a device for measuring the optical characteristics of an image displayed on the liquid crystal display panel 12 in the liquid crystal module 11 and acquiring an electrical LUT and an optical LUT. As shown in FIG. 1, the liquid crystal module 11 has a backlight 13 that emits light from the back surface of the liquid crystal display panel 12. The crosstalk correction table acquisition device 10 outputs a control unit 14 that controls each unit, a storage circuit 15 that stores a program for operating the control unit 14 and data necessary for the operation of the control unit 14, and a control unit 14. For example, DVI
(Digital Visual Interface) An image processing circuit 16 that converts a standard image signal into a signal that is compatible with the liquid crystal display panel 12, a backlight drive circuit 17 that drives the backlight 13,
An IF (interface) that mutually converts an optical measurement device 18 that measures optical characteristics such as luminance and chromaticity of an image displayed on the liquid crystal display panel 12, and an RS232C interface of the control unit 14, for example, a USB port and the optical measurement device 18. ) 19.

Next, the liquid crystal display panel 12 whose optical characteristics are measured will be described. FIG. 2 is a diagram illustrating pixels of the liquid crystal display panel 12. For example, if the liquid crystal display panel 12 is of the color WVGA standard, it has 800 pixels in the row direction (horizontal direction) and 480 pixels in the column direction (vertical direction). One pixel is composed of three sub-pixels of R (red), G (green), and B (blue), which are the three primary colors of light. As shown in FIG. 3A, the two-screen liquid crystal display panel 12 includes a color filter layer 2
A light shielding layer 21 is provided on the 0 display surface side (upper side in FIG. 3A). The light shielding layer 21 has a structure shown in FIG.
As shown in FIG. 5, the slits 22 are formed in a checkered pattern, for example.

As shown in FIG. 3A, in the two-screen liquid crystal display panel 12, one of the checkered patterns of the sub-pixels can be visually recognized only from the right direction (the driver's seat direction of the right-hand drive car) when viewed from the user. Visible only from the left (passenger seat direction of right-hand drive car). For example, the navigation screen can be viewed in the right direction, and the DVD screen can be viewed in the left direction.

The image input to the two-screen liquid crystal display panel 12 is a composite image. As shown in FIG. 4, the image includes, for example, an image in the right viewing direction of 800 pixels × 480 pixels and a left viewing direction of 800 pixels × 480 pixels. Are selected in a checkered pattern of subpixels, and one 800 pixel × 480 pixel image is synthesized. The gradation data of the sub-pixels of the input image is 6 bits, and the luminances of R, G, and B are 64 types of 0 gradation to 63 gradation. The drive control of the luminance of the liquid crystal display panel 1 is in units of one gradation. That is, a gradation that is not an integer cannot be specified. However, 1
Since the period of the screen (800 pixels × 480 pixels), that is, the frame period is as fast as 60 Hz,
Using afterimages, as shown in FIG. 5A, FRC (Frame Rate Control) is performed in units of 0.25 gradations, with 4 frames as one period and one frame increasing one gradation in one period. . For example, during a period of 1.75 gradations, 1 frame is set to 1 gradation in 4 frames in one cycle,
If the remaining 3 frames are set to 2 gradations, it will appear as 1.75 gradations due to the afterimage. Also,
In order to reduce flicker, as shown in FIG. 5B, the positions of sub-pixels to be increased by one gradation are interspersed by changing the frame position.

When different images are adjacent to each other as shown in FIG. 4, voltages of different gradations are applied to adjacent sub-pixels, and electrical crosstalk is likely to occur. For example, as shown in FIG. 6A, when the image in the left viewing direction is halftone gray and the center is black and the image in the right viewing direction is halftone gray, the center of the right viewing image is electrically Since the voltage fluctuates due to crosstalk, it is displayed in a slightly dark gray. The electrical crosstalk occurs not only in the above-described composite image but also when the gradations of adjacent subpixels are different. In particular, in the composite image, the subpixels of different images are adjacent to each other, resulting in a very large crosstalk. . For this purpose, the two-screen liquid crystal display panel 12
Then, it is necessary to correct electrical crosstalk. Further, as shown in FIG.
The light is diffracted at the periphery of the slit 22 and light from the sub-pixels of the same color of the adjacent pixels leaks. It is also necessary to correct this optical crosstalk.

FIG. 7 is a block diagram showing a two-screen display device 30 provided with a crosstalk correction unit for correcting these electric crosstalk and optical crosstalk. In FIG. 7, the solid line indicates the two-screen display device 30, and the broken line indicates the navigation device 50 in which the two-screen display device 30 is incorporated. The two-screen display device 30 is a signal processing circuit 31 that outputs the two source images (navigation image, DVD image) from the liquid crystal display panel 12 and the navigation device 50 to the liquid crystal display panel 12 after performing two-screen composition processing and crosstalk correction. And signal processing circuit 31
An EEPROM 32 for storing various data necessary for the above operation, and a power supply circuit 33 for supplying power to the liquid crystal display panel 12.

The signal processing circuit 31 can display on the liquid crystal display panel 12 a two-screen synthesis unit 34 that synthesizes two source images, a crosstalk correction unit 35 that performs crosstalk correction, and a signal corrected by the crosstalk correction unit 35. Output signal generator 36 for controlling the polarity and timing,
An EEPROM controller 37 that controls input / output of the EEPROM 32 is provided.

The crosstalk correction unit 35 includes a preprocessing unit 38, an electric correction unit 39, an optical correction unit 40, and a calculation unit 41. The pre-processing unit 38 sends necessary data from the image signal from the two-screen composition unit 34 to the electrical correction unit 39, the optical correction unit 40, and the calculation unit 41. The electrical correction unit 39 is EEPRO
An electric LUT 42 for storing an electric correction table (electric LUT) (see FIG. 8A) from the M controller 37 is provided, and the sub-pixel data to be corrected and the sub-pixel data on the right side are input from the pre-processing unit 38 and the electric LUT 42 is input. Electrical correction data is extracted from the electrical correction table.
The optical correction unit 40 receives an optical correction table (optical LUT) from the EEPROM controller 37.
) (See FIG. 8B), the sub-pixel data to be corrected and the same color sub-pixel data of the right adjacent pixel are input from the pre-processing unit 38, and the optical LUT 43 is optically read from the optical correction table. Extract correction data. The calculation unit 41 adds the electrical correction data extracted by the electrical correction unit 39 and the optical correction data extracted by the optical correction unit 40 to the correction target sub-pixel data from the preprocessing unit 38.

The EEPROM 32 stores an electrical correction table shown in FIG. 8A and an optical correction table shown in FIG. 8B. The electrical correction table stores electrical correction data of the gradations of all adjacent subpixels for all the gradations of the correction target subpixels, and the optical correction table stores all the gradations of the correction target subpixels. Optical correction data of all gradations of the same color sub-pixel of the adjacent pixel is stored. This correction data is a value obtained through experiments. When a power switch (not shown) of the navigation device 50 is turned on, the EEPROM controller 37
Transfers the electrical correction table of the EEPROM 32 to the electrical LUT 42 and transfers the optical correction table to the optical LUT 43.

There are multiple types of LUTs in the electrical correction table and the optical correction table depending on where the gradation reference for setting the correction data to 0 is used. For example, FIG. 9A shows a white-reference electrical LUT, the correction data is 0 when the gradation of adjacent sub-pixels is 63 white, and FIG. 9B shows the self-reference electrical LUT.
When the two gradations are equal, the correction data is 0. FIG. 9C is a black-reference electrical LUT, and the correction data is 0 when the gradation of the adjacent sub-pixel is the 0 gradation of black. In the present embodiment, both the electrical correction table and the optical correction table are based on white. White standard LUT is self standard LUT
As compared with the above, it is possible to broadly correct the gradation of the low-luminance portion where the difference in gradation is conspicuous. In addition,
Although there is a region that cannot be corrected slightly in the high luminance part, the luminance error is not conspicuous because the luminance is high. Also, the self-standard LUT has an advantage of high contrast.

The image processing of the two-screen display device 30 having the above configuration will be described. As shown in FIG. 7, the two-screen composition unit 34 has a navigation image of 800 × 480 pixels input from the navigation unit 51 of the navigation device 50 and 80 input from the DVD playback unit 52.
A DVD playback image of 0 pixels × 480 pixels is selected by selecting it as a checkered pattern of sub-pixels.
An image of 0 pixels × 480 pixels is synthesized. The pre-processing unit 38 of the crosstalk correction unit 35 outputs sub-pixel data (6-bit gradation data) to be corrected from the composite image input from the two-screen composition unit 34 to the electrical correction unit 39 and the optical correction unit 40. , The right sub pixel data is converted into the electric correction unit 3
Output to 9. The electrical correction unit 39 uses the electrical correction table of the electrical LUT 42 to extract electrical correction data of the input correction target sub-pixel data and the right-side sub-pixel data.
The optical correction unit 40 uses the optical correction table of the optical LUT 43 to extract optical correction data of the input sub-pixel data to be corrected and the same color sub-pixel data of the right adjacent pixel. The calculation unit 41 adds the electrical correction data extracted by the electrical correction unit 39 and the optical correction data extracted by the optical correction unit 40 to the correction target sub-pixel from the preprocessing unit 38.

As described above, the EEPROM 32 has an electrical L for performing electrical crosstalk correction.
A UT and an optical LUT for optical crosstalk correction are stored in advance. A method for obtaining the electric LUT and the optical LUT through experiments will be described. FIG. 10 is a flowchart showing the operation of the control unit 14 of FIG. 1, that is, the content of the control unit 14 executing the program stored in the storage circuit 15. The control unit 14 defines variables (see the upper right column in FIG. 10) in advance in an internal register (not shown) (step S10).

Here, red gradation array variable R (0) is 0, R (1) is 1,... R (n) is n,
... R (63) is defined as 63, array variable G (0) for green gradation is 0, G (1) is 1,
... G (n) is defined as n, G (63) is defined as 63, and blue gradation array variable B (0)
Is defined as 0, B (1) is defined as 1, B (n) is defined as n, and B (63) is defined as 63. Also,
The standard luminance array variable is defined as k1 (i1) when the non-viewing-side gradation is the reference 63-gradation (correction data is 0) and the viewing-angle-side gradation is i1. The luminance measured in a state including is defined as k2. In addition, an error rate before the update between the measured luminance and the standard luminance is defined as WF1, and an error rate after the update is defined as WF2. Temporary composite correction data (composite correction data is obtained by adding electrical correction data and optical correction data).
Is defined as h, provisional electrical correction data is defined as h1, and provisional optical correction data is defined as h2.

Furthermore, the array variable of the electrical correction data at each gradation and each gradation on the non-viewing angle side (adjacent) is defined as H1 (0,0) to H1 (63,63). The array variable of the optical correction data at the gradation and each gradation on the non-viewing angle side (adjacent) is H2 (0, 0).
) To H2 (63, 63). In addition, the standard u′v ′ chromaticity coordinate array variable when the non-viewing angle side gradation is 63 reference gradations (correction data is 0) and the viewing angle side gradation is i1 is u1 ′ (i1).
, V1 ′ (i1), and u′v ′ chromaticity coordinates measured in a state including crosstalk by the optical measuring instrument 18 are defined as u2′v2 ′, and measured u′v ′ chromaticity coordinates. The distance before the update between the standard u′v ′ chromaticity coordinates is defined as D1, and the distance after the update between the measured u′v ′ chromaticity coordinates and the standard u′v ′ chromaticity coordinates is defined as D2. To do. Note that the standard luminance k (i1) of the gradation i1 on the viewing angle side and the standard u′v ′ chromaticity coordinates u1 ′ when the gradation on the non-viewing angle side where the correction data is 0 are the reference 63 gradations. (I1) and v1 ′ (i1) are measured in advance and stored in the storage circuit 15.

The control unit 14 sets the initial value of the gradation loop variable i1 to the initial value 0, and sets the initial value of the non-viewing-angle-side gradation loop variable i2 to the initial value 0 (step S11). And the acquisition process of the composite correction data which is the sum total of electrical correction data and optical correction data is performed (step S12). Next, an electrical correction data and optical correction data acquisition process is performed (step S13). After the process of step S13, the control unit 14 increments i2 by 1 until the loop variable i2 indicating the non-viewing-angle side gradation reaches 63 of the final gradation, and repeats steps S12 to S15. When the loop variable i2 reaches 63 of the final gradation (
In step S14, the control unit 14 increments i1 by 1 and returns the loop variable i2 to 0 until the loop variable i1 indicating the viewing-side gradation reaches the final gradation 63. Steps S12 to S17 are repeated. When the loop variable i1 reaches the final gradation 63 (Y in step S16), the control unit 14 ends the process.

FIG. 11 is a subroutine of the composite correction data acquisition process which is step S12 of FIG. The control unit 14 sets the variable h of the provisional composite correction data to the minimum 0, and sets the error rate variable WF1 before the update of the measured luminance and the standard luminance to the maximum 1 (step S20). Then, the control unit 14 sets R (i
1 + h), G (i1 + h), and B (i1 + h), the gradation of the sub-pixel on the non-viewing angle side is R (i2)
, G (i2), B (i2) (step S21). FIG. 13A shows step S21.
It is a figure which shows the display state of. As shown in FIG. 13A, all the RGB subpixels on the viewing angle side need electrical crosstalk correction and optical crosstalk correction corresponding to the gradation i2 of the non-viewing angle side subpixel.

The control unit 14 uses the value measured by the optical measuring instrument 18 as the brightness measurement data of this display as a variable k (step S22), and the error rate WF2 with respect to the array function k1 (i1) of the standard brightness at this gradation. = Abs ((k1 (i1) -k) / k1 (i1)) is calculated (step S2
3). The control unit 14 increments the gradation of the sub-pixel on the viewing angle side by 0.25 gradation, which is the minimum unit of FRC, until the error rate becomes the lowest, and correction data when the error rate becomes the lowest h is obtained (steps S24 to S27).

Specifically, the control unit 14 determines that the error rate WF2 calculated in step S23 is the error rate W before update.
If it is smaller than F1 (N in step S24), the error rate WF1 is updated to the error rate WF2 on the assumption that there is still correction data with the lowest error, and then the temporary error rate h is added by 0.25 (
Step S25). If i1 + h does not exceed the maximum 63 (step S26).
N), the process returns to step S21. The control unit 14 calculates the error rate WF2 calculated in step S23.
Is equal to or higher than the error rate WF1 before the update (Y in step S24), the current correction data h is subtracted by 0.25, assuming that the error rate WF2 is the lowest at the time of the correction data of the previous loop. (Step S27). The correction data h is the sum of electrical correction data and optical correction data. If i1 + h exceeds the maximum 63, the control unit 14 determines that an abnormal state has occurred and proceeds to step S27 to exit the loop. As shown in FIG. 13A, the correction data h obtained in step S27 is the electrical correction data and the optical correction data when the gradation of the subpixel on the viewing angle side is i1 and the subpixel on the non-viewing angle side is i2. Are combined.

FIG. 12 is a subroutine of individual correction data acquisition processing which is step S13 of FIG. The control unit 14 sets the temporary electrical correction data h1 to the variable h of the temporary composite correction data obtained in step S27, sets the temporary optical correction data h2 to 0, and measured u′v '
The distance D1 before the update between the chromaticity coordinates and the standard u′v ′ chromaticity coordinates is set to a large value 10 (step S30). Then, the control unit 14 uses R (i1), G (i1 + h1), and B (i1 + h2) for the gradations of the sub-pixels on the viewing angle side of at least the entire optical measurement region, and R ( 63), G (63), and B (i2) are displayed (step S31). FIG. 13B is a diagram showing a display state in step S31. Since this LUT is based on white, the correction data is 0 when the non-viewing angle side sub-pixel gradation is 63 white display. Thus, FIG. 13B
As shown in FIG. 4, only the G subpixel on the viewing angle side, which uses the B subpixel on the non-viewing angle side as an adjacent subpixel, requires electrical crosstalk correction, and only the B subpixel on the viewing angle side has optical crosstalk correction. Requires correction.

The control unit 14 uses the value measured by the optical measuring device 17 as the variable k for the u′v ′ chromaticity coordinate of this display (step S32), and the distance D2 = ((u2) to the standard u′v ′ chromaticity coordinate. '-U1' (
i1)) ^ 2+ (v2'-v1 '(i1)) ^ 2) ^ 0.5 is calculated (step S33).
. The controller 14 sends the provisional electrical correction data h1 to the FRC until the distance D2 becomes the minimum.
When the distance D2 becomes the minimum by incrementing the tentative optical correction data h2 by 0.25 gradation, which is the minimum unit of FRC. Electrical correction data h1 and provisional optical correction data h2 are obtained (steps S31 to S36).

Specifically, if the distance D2 calculated in step S33 is not equal to or greater than the distance D1 before update (N in step S34), the control unit 14 updates the distance D1 to the distance D2 on the assumption that there is correction data that minimizes the distance. Then, the provisional electrical correction data h1 is subtracted by 0.25 gradations, and the provisional optical correction data h2 is added by 0.25 gradations (step S35). If the variable h1 is not negative (N in step S36), the process returns to step S31. If the distance D2 calculated in step S33 is equal to or greater than the distance D1 before the update (Y in step S34), the control unit 14 assumes that the distance D2 is the minimum at the time of the previous loop correction data, and The electrical correction data h1 obtained by adding 0.25 gradations is stored in the storage circuit as electrical LUT correction data, and the provisional optical correction data h2 obtained by subtracting 0.25 gradations is optical L.
The data is stored in the storage circuit as UT correction data (step S37). If the variable h1 is negative (Y in step S36), the control unit 14 determines that an abnormal state has occurred and proceeds to step S37 to exit the loop.

As described above, the present invention obtains the sum of the correction data for the electrical LUT and the correction data for the optical LUT in step S12, and in step S13, the sub-pixel for only one of the gradations of the RGB three-color sub-pixels on the non-viewing angle side. Is displayed with gradations other than the correction data 0, the electrical sub-pixels to be corrected and the optical sub-pixels to be corrected are separated by RGB, and the correction data for the electrical LUT and the optical LUT are corrected. The electrical LUT correction data and the optical LUT correction data are obtained by changing the condition gradation of the total value of the data, so that the electrical LUT correction data and the optical LUT correction data can be easily obtained with a small gradation change. be able to. The LUT has a large amount of correction data. Since the correction data acquisition operation is performed by a program, the LUT can be automated, and human labor can be reduced. Since the LUT is based on white, there is no negative correction value. That is, since the minimum value of the correction value is 0, as in step S20 and step S30, if an initial value of temporary correction is started from 0 and incremented in an experiment, a correction value that provides optimum optical characteristics is obtained. Good. On the other hand, since the correction value is both positive and negative according to its own standard, the minimum value of the correction value is undetermined. Therefore, when finding a correction value that provides optimal optical characteristics in an experiment, a very large provisional correction value must be set, or both increment and decrement must be performed. Time consuming. As described above, the correction table can be acquired in a short time by using the white reference.

Note that the above-described LUT was based on white, but by setting 63 gray levels on the white basis to 0 levels,
The present invention can be easily applied to the black standard. It can also be applied to its own standards. FIG. 14A is a self-reference diagram corresponding to FIG. 13A of the white reference, and FIG. 14B is a self-reference diagram corresponding to FIG. 13B of the white reference. As in 13B, the correction data is 0 when the gradations on the viewing angle side and the non-viewing angle side are equal to each other on the basis of itself, so if only the two colors of RGB on the non-viewing angle side are set to the same gradation i1 on the viewing angle side. Good.

DESCRIPTION OF SYMBOLS 10: Optical measuring system 11: Liquid crystal module 12: Liquid crystal display panel 13: Backlight 14: Control part 15: Memory circuit 16: Image processing circuit 17: Backlight drive circuit 18: Optical measuring device 19: IF 20: Color filter layer 21: Light shielding layer 22
: Slit 30: Two-screen display device 31: Signal processing circuit 32: EEPROM 33:
Power supply circuit 34: Two-screen composition unit 35: Crosstalk correction unit 36: Output signal generation unit 37: EEPROM controller 38: Pre-processing unit 39: Electric correction unit 40: Optical correction unit 41: Calculation unit 42: Electric LUT 43: Optical LUT 50: Navigation device 51: Navigation unit 52: DVD playback unit

Claims (4)

Electrical crosstalk and optics generated on a liquid crystal display panel that displays a first image and a second image in which three sub-pixels constituting one pixel of RGB are alternately adjacent to each other in a different viewing direction by shading of a slit. To correct typical crosstalk, an electrical correction table consisting of correction data corresponding to the gradation of the subpixel to be corrected and the gradation of the adjacent subpixel, and the same color of the gradation of the subpixel to be corrected and the adjacent pixel An optical correction table comprising correction data corresponding to the sub-pixels is provided, and the gradation based on the correction data in the electrical correction table and the gradation based on the correction data in the optical correction table are included in the gradation of the sub-pixel to be corrected. A crosstalk correction table that acquires the electrical correction table and the optical correction table of a crosstalk correction unit that performs crosstalk correction by adding In the acquisition device,
The gradation reference value for which the correction data is 0 is set to the gradation of the subpixel of the same color of the adjacent subpixel and the gradation of the adjacent pixel with respect to the gradation of the subpixel to be corrected. The electrical correction table and the optical correction table in which gradation is corrected so that an error from the optical characteristic when the optical characteristic of the pixel is the reference value is small,
An optical measuring instrument for measuring optical characteristics of the first image displayed on the liquid crystal display panel when the sub-pixel to be corrected is the first image; and the liquid crystal display panel measured by the optical measuring instrument. An apparatus for acquiring a crosstalk correction table, comprising: a control unit that displays a gradation of only one sub-pixel of the gradation of RGB sub-pixels of the second image in the region other than the reference value. . The correction data H1 (i1, i2) of the electrical correction table and the optical when the gradation of the sub-pixel to be corrected is i1 and the gradation of the sub-pixel of the same color of the adjacent sub-pixel is i2. When acquiring the correction data H2 (i1, i2) of the correction table,
The gradation of all RGB sub-pixels of the first image in the region measured by the optical measuring instrument corresponds to i1, and the gradation of all RGB sub-pixels of the second image corresponds to the gradation i1 of the first image. The luminance of the first image at the reference value B (i1) to be used is the standard luminance k1 (i1), and the u′v ′ chromaticity coordinate of the first image at that time is the standard u′v ′ color. A storage circuit that stores the coordinates as degree coordinates u ′ (i1), v ′ (i1),
The control unit causes the gradation of all the RGB sub-pixels of the second image to be i2, and changes the gradation of all the sub-pixels of the first image with the same value h, whereby the luminance of the first image is increased. Correction data h that is the luminance of the first image closest to the standard luminance k1 (i1) is obtained, and this correction data h is obtained as correction data H1 (i1, i2) of the electrical correction table and correction data H2 ( i1, i2)
The control unit causes the gradation of one of the three sub-pixels of RGB of the second image to be i2, and causes the gradation of the remaining two sub-pixels to be the reference value B (i1). The gradation of the subpixel of the first image in which the subpixel i2 is the adjacent subpixel is changed by h1, and the subpixel level of the first image in which the subpixel of the gradation i2 is the same color subpixel of the adjacent pixel is changed. By changing the tone h−h1 = h2, the u′v ′ chromaticity coordinate of the first image becomes the standard u′v ′ chromaticity coordinate u ′ (i1), v ′.
H1 and h2, which are the luminances of the first image closest to (i1), are obtained, h1 is the correction data H1 (i1, i2) of the electrical correction table, and h2 is the correction data H of the optical correction table.
2. The crosstalk correction table acquisition device according to claim 1, wherein 2 (i 1, i 2) is stored in the storage circuit. 2. The crosstalk correction table acquisition apparatus according to claim 1, wherein the reference value for setting the correction data to 0 is a gradation at which adjacent subpixels and the same color subpixels of adjacent pixels display white. The reference value for setting the correction data to 0 is a gradation in which the gradation of the adjacent subpixel and the same color subpixel of the adjacent pixel is the same as the gradation of the correction target subpixel. Crosstalk correction table acquisition device.

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