JP2000209603A - Device for correcting uneven color and method for correcting uneven color - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an uneven color correction device that corrects the difference of display (color and luminance) for various positions of a screen, and a method for the correction. SOLUTION: An image input section 2 captures an image displayed on a screen of a display device 1. A correction waveform calculation section 3 receives the image by RGB signals and calculates an error between each of the signals and a reference signal (waveform) as correction data. The correction data are transferred to a correction waveform generating section 4. The generating section 4 outputs the correction data to a modulation section 5 in matching timing when the RGB signal is sent to the display device 1. Thus, the modulation section 5 modulates the RGB signals by using the correction data corresponding to them respectively and the RGB signals after the modulation are transferred to the display device 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for correcting a change in color or luminance of an image caused by a position on a display screen.

[0002]

2. Description of the Related Art Heretofore, in a projector using a liquid crystal as a display device, a gap in a liquid crystal filled portion has been varied due to a reason for manufacturing a liquid crystal plate, thereby causing color unevenness. The color shading remained even when actually displayed.

[0005] Even if the color unevenness is such that it cannot be recognized by itself, it is easy to recognize the color difference between adjacent projectors when constructing a multi-projector system or the like. For this reason, conventionally, adjustment has been performed so as to make the color difference inconspicuous by changing the RGB balance of the entire screen.

[0004]

However, in the conventional method, when the color differs depending on the location such as the upper portion and the lower portion in one screen, the difference in the color depending on the location is not corrected even if the overall balance is changed. There is a problem that the color difference between adjacent projectors cannot be made inconspicuous.

An object of the present invention is to provide a color non-uniformity correction apparatus for correcting a difference in display state (color and luminance) depending on a position in a screen, and a method therefor.

[0006]

According to a first aspect of the present invention, there is provided a color non-uniformity correcting apparatus which reads an image displayed on a display screen, based on the image read by the image reading means. A correction amount calculation unit that calculates a correction amount based on a position on the display screen, and a correction unit that corrects data of an image displayed on the display screen using the correction amount calculated by the correction amount calculation unit, Is provided.

In the above arrangement, it is preferable that the correction amount calculating means calculates a correction amount for correcting a difference in color or luminance depending on a position on the display screen.

[0008] A color unevenness correction apparatus according to a second aspect of the present invention comprises:
Image reading means for reading images displayed on a plurality of display screens arranged adjacent to each other, and a correction amount by a position on the display screen for each display screen based on each image read by the image reading means. And a correction unit that corrects data of images displayed on the plurality of display screens using the correction amount calculated by the correction amount calculation unit.

In the above arrangement, it is preferable that the correction amount calculating means calculates a correction amount for correcting a difference in color or luminance between adjacent display screens.

[0010] The color unevenness correction method according to the first aspect of the present invention comprises:
An image displayed on the display screen is read, a correction amount based on a position on the display screen is calculated based on the read image, and an image displayed on the display screen is calculated using the calculated correction amount. Correct the data of.

According to a second aspect of the present invention, there is provided a method of correcting color unevenness.
Each of the images displayed on the plurality of display screens arranged adjacently is read, and a correction amount based on the position on the display screen is calculated for each display screen based on each of the read images,
The data of the images displayed on the plurality of display screens are respectively corrected using the calculated correction amounts.

[0012]

Embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram of a color shading correction apparatus according to a first embodiment. In FIG. 1, first, a display device 1
Displays a predetermined image on the display screen. The image displayed thereon is taken into the image input unit 2.

Images captured by the image input unit 2 are RGB
Are input to the correction waveform calculator 3 for each of the signals. The correction waveform calculator 3 calculates an error between the signal and a reference signal (waveform) as correction data. The reference signal is
This is used for displaying an image on the display device 1 first.

The correction data is transferred to the correction waveform generator 4. The generator 4 outputs the correction data to the modulator 5 at the timing when the RGB signals are sent to the display device 1. Thereby, the modulation unit 5 modulates (eg, multiplies) the RGB signals using the correction data corresponding thereto.
Are performed, and the modulated RGB signals are displayed on the display device 1.
To transfer.

As described above, in the present invention, since the image actually displayed on the display screen of the display device 1 is input as the image to be corrected, not only the color unevenness of the liquid crystal but also the luminance due to the variation of the lamp and the optical system. It is possible to perform correction including unevenness and a decrease in luminance at the peripheral portion due to the viewing angle characteristics of the screen. Further, when the correction is repeatedly performed, the color unevenness and the luminance unevenness can be corrected with higher accuracy.

FIG. 2 is a block diagram of a color shading correction apparatus according to a second embodiment. The second embodiment is similar to the first embodiment.
Is applied to a liquid crystal projector. For this reason, basically the same components are denoted by the same reference numerals, and redundant description will be omitted.

In the second embodiment, as shown in FIG. 2, an all white screen displayed on a liquid crystal projector 11 is photographed by a video camera 12, and the photographed image is taken into a computer 13 as a target image. Has become.

The computer 13 calculates an error from a reference signal (a signal for displaying an all-white screen) from the captured image, and, based on the difference, separates each of the RGB signals for each pixel (or its block). ) Calculate the correction data separately.
The correction data is transferred to the correction waveform generator 4 and sent to the modulator 5 via the correction waveform generator 4. Thereby,
The modulation unit 5 modulates (multiplies) the RGB signals using the corresponding correction data.

As described above, in the second embodiment, the RG
Since the B signal is individually corrected for each color based on the same reference waveform, the color unevenness of the liquid crystal can be removed, and a uniform color can be obtained on the entire screen (screen). That is, color unevenness on the screen of the liquid crystal projector 1 can be corrected.
Because the correction uses the image actually projected on the screen as a sample, it is not only a color unevenness of the liquid crystal,
Correction can be performed with high accuracy, including luminance unevenness due to variations in lamps and optical systems, and peripheral luminance reduction due to the viewing angle characteristics of the screen.

Although the second embodiment is directed to a liquid crystal projector as a display device, the present invention is not limited to the liquid crystal projector, but includes a projector using other devices such as a CRT and a mirror device, a liquid crystal monitor, a plasma display panel, and the like. The present invention can also be applied to a system using. Also, the present invention can be applied to a system having a plurality of screens, such as a multi-projector system. When applied to such a system, correction data may be calculated so that there is no difference in color or luminance between adjacent screens.

[0022]

As described above, according to the present invention,
Since the image actually displayed on the screen is captured and the correction amount for the image data is calculated based on the image, not only the color unevenness of the liquid crystal but also the brightness unevenness due to lamp and optical system variations and the viewing angle characteristics of the screen The correction including the lowering of the luminance of the peripheral portion due to the above can be performed with high accuracy.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a color shading correction apparatus according to a first embodiment.

FIG. 2 is a configuration diagram of a color shading correction apparatus according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Display apparatus 2 Image input part 3 Correction waveform calculation part 4 Correction waveform generation part 5 Modulation part 11 Liquid crystal projector 12 Video camera 13 Computer

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) BB53 BD02 CA12 CA81 CB05 CB08 EA20 MM06 MM10

Claims (6)

[Claims] An image reading unit that reads an image displayed on a display screen; a correction amount calculation unit that calculates a correction amount based on a position on the display screen based on the image read by the image reading unit; A correction unit that corrects data of an image displayed on the display screen using the correction amount calculated by the correction amount calculation unit. 2. The color non-uniformity correction apparatus according to claim 1, wherein the correction amount calculation means calculates a correction amount for correcting a difference in color or luminance depending on a position on the display screen. . 3. An image reading means for reading images displayed on a plurality of display screens arranged adjacent to each other, and a correction amount based on a position on the display screen based on each image read by the image reading means. Correction amount calculation means for calculating each of the display screens, and correction means for respectively correcting data of images displayed on the plurality of display screens, using the correction amount calculated by the correction amount calculation means, A color non-uniformity correction device, comprising: 4. The color non-uniformity correction apparatus according to claim 3, wherein the correction amount calculating means calculates a correction amount for correcting a difference in color or luminance between adjacent display screens. . 5. An image displayed on a display screen is read, a correction amount based on a position on the display screen is calculated based on the read image, and the correction amount is calculated on the display screen using the calculated correction amount. A method of correcting color unevenness, wherein data of an image displayed on the image is corrected. 6. An image displayed on a plurality of display screens arranged adjacent to each other is read, and a correction amount based on a position on the display screen is calculated for each display screen based on each of the read images. And correcting the data of the images displayed on the plurality of display screens by using the calculated correction amount.