JP2003241712A - Video display device provided with color organic el panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video display device which is provided with a color organic EL (electroluminescence) panel and which is capable of presenting a brighter video on a screen on which a large proportion is occupied by green color. <P>SOLUTION: The video display device provided with a color organic EL panel is provided with a G-signal correcting and processing circuit which corrects the level of an input G signal based on the level of the input G signal and the level of an input B signal. The G signal correcting and processing circuit enlarges the level of the input G signal in a region where the proportion occupied by the G signal is large in an input video. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a color organic EL device.
The present invention relates to an image display device provided with a panel.

[0002]

2. Description of the Related Art In recent years, an organic EL element using an organic electroluminescence (EL) phenomenon has been developed by Mr. C. W. Tang of Eastman Kodak Company. Such an organic EL element is a self-luminous display element that can be driven by a low-voltage direct current, and has advantages over a liquid crystal panel, such as a wide viewing angle, a bright display surface, and a thin and light body. is doing. Therefore, it is highly expected as a display element for wall-mounted or portable televisions.

By the way, when the organic EL element is used as a display element of a color television, one color pixel is composed of three organic EL elements which respectively emit RGB light. In such a display panel, depending on the type of organic EL element, there is a problem that the coloring performance of each of the RGB light emitting elements becomes insufficient and the displayed image looks unnatural. In particular, depending on the type of organic EL element, there is a problem in the light emitting characteristic of the G light emitting element (emission luminance characteristic with respect to the input gradation), and there is a problem that a screen dominated by green, such as a forest scene, becomes dull. .

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image display device provided with a color organic EL panel which can present a more vivid image in a region where green is large. And

[0005]

According to a first aspect of the present invention, in an image display device having a color organic EL panel, the input G signal level is corrected based on the input R signal level and the input B signal level. A G signal correction processing circuit is provided.

According to a second aspect of the present invention, in the image display device provided with the color organic EL panel according to the first aspect, the G signal correction processing circuit is arranged in a region where the G signal occupies a large portion of the input image. , The input G signal level is increased.

According to a third aspect of the present invention, in the image display device provided with the color organic EL panel according to the first aspect, the G signal correction processing circuit receives an input for each input RGB signal corresponding to each color pixel. Determining means for determining whether or not a condition that the G signal level is higher than a predetermined multiple of the input R signal and higher than a predetermined multiple of the input B signal is satisfied; and when the above condition is satisfied, the input G signal It is characterized in that a G signal enhancing means for increasing the level is provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of a television in which a color organic EL panel is used as a display element.

In this embodiment, it is assumed that the G light emitting element in the color organic EL panel 7 has a lower emission luminance with respect to the input gradation than the light emitting elements of other colors.

The radio wave of the television broadcast received by the antenna 1 is demodulated by the tuner 2 and then transmitted by the NTSC.
The decoder circuit 3 extracts the RGB signal and the audio signal.

The RGB signal obtained by the NTSC decoder circuit 3 is converted into 8-bit RGB digital data by the AD conversion circuit 4, and then input to the G signal correction processing circuit 5. The G signal correction processing circuit 5 performs correction processing (G signal correction processing) on the G data based on the input RGB data and then outputs 8-bit RGB digital data.

RG output from the G signal correction processing circuit 5
The B data is converted into analog data by the DA conversion circuit 6 and then sent to the color organic EL panel 7 for display.

The audio signal obtained by the NTSC decoder circuit 3 is sent to the speaker 9 via the audio output circuit 8 and is output as audio. The tuner 2, the NTSC decoder circuit 3, and the color organic EL panel 7 are controlled by the control circuit 10.

The G signal correction processing circuit 5 is a color organic EL.
Considering that the emission brightness of the G light emitting element in the panel 7 with respect to the input gradation is lower than the emission brightness of the RB light emitting element with respect to the input gradation, the G
Performs processing for emphasizing the signal. In order to emphasize the G signal only in the area occupied by a lot of green, the G signal is emphasized in other areas.
This is because the color balance is lost when the signal is emphasized.

FIG. 2 shows a G signal correction processing procedure by the G signal correction processing circuit 5.

The G signal correction process is performed for each input RGB signal corresponding to each color pixel. FIG. 2 shows a G signal correction processing procedure performed on an input RGB signal corresponding to one color pixel (color pixel of interest).

First, based on the input G data (0-255) and the input R data (0-255) corresponding to the color pixel of interest, it is determined whether or not the first condition shown in the following equation (1) is satisfied. Is determined (step 1).

G> a · R (1)

In the above equation (1), a is a constant,
For example, it is set to a value within the range of 5 to 7.

When the first condition is not satisfied, the G data is not corrected. That is, the input G data is output as it is as G data. When the first condition is satisfied, the second condition represented by the following equation (2) is based on the input G data (0 to 255) and the input B data (0 to 255) corresponding to the target color pixel. It is determined whether or not (step 2).

G> b · B (2)

In the above equation (2), b is a constant,
For example, it is set to a value within the range of 5 to 7.

When the second condition is not satisfied, the G data is not corrected. That is, the input G data is output as it is as G data. If the second condition is satisfied, the G data is corrected based on the following equation (3) (step 3).

G '= cG (3)

In the above equation (3), G'is the corrected G
Represents data. Further, c is a constant, and is set to a value within the range of 1.1 to 1.2, for example.

Thereafter, it is judged whether or not the G data (G ') corrected in step 3 exceeds 255 (step 4). When the G data (G ′) corrected in step 3 does not exceed 255, the G data (G ′) corrected in step 3 is output as G data.

G data (G ') corrected in step 3
If the value exceeds 255, the value of G data (G ′) is changed to 255 (step 5) and then output as G data.

By performing the G signal correction processing as described above, the color balance in a normal image is maintained, and the G signal is emphasized on a screen where green is dominant such as a forest scene to present a more vivid image. Can be made.

In the above-described embodiment, G is set for each color pixel.
Although the signal correction process is performed, it is determined whether or not the area is occupied by a large amount of green for each larger unit area, and the G signal for the area determined to be an area occupied by a large amount of green is emphasized. Good.

[0031]

According to the present invention, it is possible to present a more vivid image in a region where green is dominant.

[Brief description of drawings]

FIG. 1 shows a configuration of a television in which a color organic EL panel is used as a display element.

FIG. 2 shows a G signal correction processing procedure by a G signal correction processing circuit 5.

[Explanation of symbols]

5 G signal correction processing circuit 7 color organic EL panel 10 Control circuit

Claims (3)

[Claims] 1. An image display device provided with a color organic EL panel, comprising a G signal correction processing circuit for correcting an input G signal level based on an input R signal level and an input B signal level. Color organic EL
Video display device with a panel. 2. The color organic EL device according to claim 1, wherein the G signal correction processing circuit increases the input G signal level in a region where the ratio of the G signal in the input image is large. Video display device with a panel. G signal enhancement 3. The G signal correction processing circuit has an input G signal level higher than a predetermined multiple of an input R signal and an input B signal for each input RGB signal corresponding to each color pixel.
And a G signal emphasizing unit for increasing the input G signal level when the condition that the signal is greater than a predetermined multiple is satisfied, and the condition that the input G signal level is increased. An image display device comprising the color organic EL panel according to claim 1.