DISPLAY APPARATUS

• US 20070273701A1
• Filed: 03/13/2007
• Published: 11/29/2007
• Est. Priority Date: 04/05/2006
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Inventors: Mizukoshi, Seiichi, Kohno, Makoto, Onomura, Kouichi
• Granted Patent: US 8,022,908 B2
• Time in Patent Office: Days
• US Class Current: 345/531
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2340/0492 Change of orientation of the displayed image, e.g. upside-down, mirrored
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters

Abstract

After a look-up table applies y correction to each of R, G, and B signals, a multiplier multiplies a y corrected signal by a gain. An adder adds an offset to an output of the multiplier and supplies a resultant gain/offset corrected signal to a display panel. Memories store entropy coded correction data, which can be expanded by corresponding expansion circuits and supplied to the multiplier and the adder, respectively.

Claims

1. A display apparatus, comprising:

control means for controlling the display of pixels constituting a screen display based on input data;

a correction memory storing correction data for eliminating unevenness in brightness among respective pixels; and

correcting means for correcting brightness irregularities based on the data stored in the memory and the input data, wherein the correction data stored in the correction memory are entropy coded data, and

the correcting means being configured to expand the entropy coded data and calculate correction values based on expanded data and the input data.

2. The display apparatus according to claim 1, wherein the entropy coded data are obtained by Huffman coding.

3. The display apparatus according to claim 2, wherein the correction memory stores Huffman tables differentiated for small areas.

4. The display apparatus according to claim 3, wherein the Huffman table is determined based on display characteristics of each pixel in the display apparatus.

5. The display apparatus according to claim 1, wherein:

the correction memory stores brightness irregularity correction data for each small area consisting of a plurality of pixels on the screen display; and

the display is controlled by combining brightness irregularity correction of the small area and correction based on the entropy coded data stored in the correction memory.

6. The display apparatus according to claim 1 further comprising a buffer memory that is independent of the correction memory and can hold input data of two horizontal lines, wherein:

the input data are successively written into the buffer memory; and

an image inversed in the lateral direction is displayed by reading the input data from a final pixel to a leading pixel in each line and performing calculations based on readout data and the correction data.

7. The display apparatus according to claim 1, wherein:

the correction memory stores correction data in such a manner that a correction data storage location of a leading pixel of each horizontal line can be identified; and

the correcting means reverses a vertical scanning direction of a display panel, successively reads and expands compressed correction data from a final horizontal line to a leading horizontal line of the correction memory, and calculates the correction values based on the expanded data and the input data, thereby displaying an image inverse in the vertical direction.

8. The display apparatus according to claim 6, wherein:

the correction memory stores correction data in such a manner that a correction data storage location for a leading pixel of each horizontal line can be identified; and

the correcting means reverses a vertical scanning direction of a display panel, successively reads and expands compressed correction data from a final horizontal line to a leading horizontal line of the correction memory, and calculates the collection values based on the expanded data and the input data of a corresponding pixel read out of the buffer memory, thereby displaying an image inverse in both the lateral and vertical directions.

9. The display apparatus according to claim 1, wherein each pixel has an organic EL element having light-emitting capability.