Correction of pixels in an organic EL display device

• US 20040150592A1
• Filed: 12/30/2003
• Published: 08/05/2004
• Est. Priority Date: 01/10/2003
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Eastman Kodak Company
• Inventors: Mori, Nobuyuki, Mizukoshi, Seiichi, Kohno, Makoto, Onomura, Kouichi
• Granted Patent: US 7,345,660 B2
• Time in Patent Office: Days
• US Class Current: 345/76
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2320/0223 Compensation for problems related to R-C delay and attenuation in electrodes of matrix panels, e.g. in gate electrodes or on-substrate video signal electrodes
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element

Abstract

An organic electroluminescent display device in which display pixels containing organic electroluminescent elements are arranged in a matrix, comprising:

a correction value formula storage section for storing a correction value formula or coefficients thereof that prescribes a relationship of pixel positions for display and brightness correction data of those pixels;

a correction value output section for receiving the input of data for the positions of respective pixels, and outputs correction values for the respective pixels using the correction value formula or coefficients thereof stored in said correction value formula storage section; and

the correction value output section corrects brightness data for each pixel using the correction value from said correction value output section according to the pixel position, to thereby perform display to the respective display pixels.

Claims

1. An organic electroluminescent display device in which display pixels containing organic electroluminescent elements are arranged in a matrix, comprising:

a correction value formula storage section for storing a correction value formula or coefficients thereof that prescribes a relationship of pixel positions for display and brightness correction data of those pixels;

a correction value output section for receiving the input of data for the positions of respective pixels, and outputs correction values for the respective pixels using the correction value formula or coefficients thereof stored in said correction value formula storage section; and

the correction value output section corrects brightness data for each pixel using the correction value from said correction value output section according to the pixel position, to thereby perform display to the respective display pixels.

7. An organic electroluminescent display device according to claim 1, further comprising:

an emission controller for selectively illuminating organic electroluminescent elements of display pixels in a predetermined plurality of small areas within the display area wherein display pixels are arranged in a matrix;

a current detector for detecting a driving current for each of the small areas at the time of selective emission of the small areas;

a correction value formula generator for estimating a trend in non-uniformity of brightness of the respective pixels in the overall display area based on the detected driving current for each of the small areas and determining said correction value formula or coefficients thereof based on the estimated trend in non-uniformity of brightness; and

wherein the correction value formula, or coefficients thereof, determined by said correction value formula generator is stored in said correction value formula storage section.

2. An organic electroluminescent display device in which display pixels containing organic electroluminescent elements are arranged in a matrix, comprising:

a correction value storage section for storing line positions for either of horizontal or vertical display directions and brightness correction data for pixels of those line positions;

a correction value output section for receiving the input of data for the positions of respective pixels and outputting correction values for the respective pixels based on a relation of the line positions for the respective pixels stored in said correction value storage section and the correction value; and

the correction value output section corrects brightness data for each pixel using the correction value from said correction value output section according to the pixel position, to thereby perform display to the respective display pixels.

8. An organic electroluminescent display device according to claim 2, further comprising:

an emission controller for selectively illuminating organic electroluminescent elements of display pixels on predetermined lines in either horizontal or vertical direction within the display area wherein display pixels are arranged in a matrix;

a current detector for detecting a driving current for each of the lines at the time of selective emission of the lines;

corresponding relationship determination means for obtaining a corresponding relationship between the position of a line and a correction value for pixels on the line based on the detected driving current for each of the predetermined lines; and

wherein the correction values provided by the corresponding relationship determination means are stored in said correction value storage section.

3. A method of manufacturing an organic electroluminescent display device in which display pixels containing organic electroluminescent elements are arranged in a matrix, comprising:

selectively illuminating organic electroluminescent elements of display pixels in a predetermined plurality of small areas within a display area in which the display pixels are arranged in a matrix, and detecting a driving current for each of the small areas at this time;

estimating a trend in non-uniformity of brightness of the respective pixels in the overall display area based on the detected driving current for each of the small areas; and

storing correction data for correcting image data for each pixel input based on the estimated trend in non-uniformity of brightness.

4. A method of manufacturing an organic electroluminescent display device according to claim 3, wherein

said small area is not less than 1 pixel, small area pairs are separated, and there are pixels for which the current amount is not measured.

5. A method of manufacturing an organic electroluminescent display device according to claim 3 wherein, said correction data is a correction value formula or coefficients thereof which prescribes a relationship of pixel positions for display and brightness correction data of those pixels.

6. A method of manufacturing an organic electroluminescent display device according to claim 3, wherein

said small area is a line having pixels for either of the horizontal or vertical display directions, and said correction data is brightness correction data for the pixels in the line.