Drive apparatus for self light-emitting display

• US 6,091,398 A
• Filed: 09/11/1997
• Issued: 07/18/2000
• Est. Priority Date: 09/20/1996
• Status: Expired due to Term

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Pioneer Electronic Corporation (Pioneer Corporation)
• Inventors: Shigeta, Tetsuya
• Primary Examiner(s): Saras, Steven J.
• Assistant Examiner(s): Alphonse, Fritz
• Application Number:
  US08/927,528
• Time in Patent Office: 1,041 Days
• Field of Search: 345/204, 345/173, 345/147, 345/148, 345/149, 348/798, 348/472, 348/564, 358/444, 358/451, 395/109
• US Class Current: 345/204
• CPC Class Codes: G09G 2320/0266 Reduction of sub-frame artefacts
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/2051 with use of a spatial dither pattern
• CPC Class Codes: G09G 3/2803 Display of gradations G09G3/288 takes precedence
• CPC Class Codes: G09G 3/288 using AC panels

Abstract

A drive apparatus for a self light-emitting display unit accomplishes pseudo intermediate tone display and pseudo outline compensation while maintaining a high image quality. In executing dithering-based pseudo intermediate tone display and pseudo outline compensation data conversion on pixel data corresponding to the individual pixels of the self light-emitting display unit, dither coefficients to be added to the individual pieces of pixel data are changed field by field in this dithering process. Furthermore, the pseudo outline compensation data conversion performed is associated with each dither coefficient added in the dithering process.

Claims

1. A self light-emitting display unit comprising:

an A/D converter for sampling a video signal to convert said video signal to pixel data corresponding to individual pixels of said self light-emitting display unit;

a dithering circuit for acquiring, as dithered pixel data, upper bits of each of dither-added pixel data obtained by adding first and second sets of dither coefficients to said pixel data corresponding to a plurality of adjacent pixels on a screen of said self light-emitting display unit;

a pseudo outline compensation data converter for converting said dithered pixel data based on a first conversion table and a second conversion table to yield pseudo outline compensation pixel data; and

drive means for driving individual pixels of said self light-emitting display unit for light emission based on said pseudo outline compensation pixel data,

wherein said dithering circuit changes said dither coefficients to be added to said pixel data corresponding to individual pixels for each field of said video signal, and wherein said pseudo outline compensation data converter uses said first conversion table for converting said dithered pixel data acquired by using said dither-added pixel data obtained by adding said first set of dither coefficients and uses said second conversion table for converting said dithered pixel data acquired by using said dither-added pixel data obtained by adding said second set of dither coefficients.

2. The drive apparatus according to claim 1, wherein said drive means divides one frame to a plurality of subframes having light emission periods corresponding to individual bit positions of pixel drive data, further divides a subframe corresponding to a bit position with a heavy weight into a plurality of subframes, and causes pixels of said self light-emitting display unit to emit light only in those subframes associated with said pixel drive data;

and

each of said first and second conversion tables is a conversion pattern for converting a bit pattern of said pseudo outline compensation pixel data in such a manner that light emission positions in subframes having an equal light emission period become different from one another.

3. The drive apparatus according to claim 1, wherein said drive means divides one frame to a plurality of subframes having light emission periods corresponding to individual bit positions of pixel drive data, further divides a subframe corresponding to a bit position with a heavy weight into a plurality of subframes, and causes pixels of said self light-emitting display unit to emit light only in those subframes associated with said pixel drive data;

and

each of said first and second conversion tables is a conversion pattern for converting a bit pattern of said pseudo outline compensation pixel data in such a manner that light emission positions in subframes having an equal light emission period become different from one another.

4. The drive apparatus according to claim 1, wherein said dithering circuit respectively adds a first dither coefficient, a second dither coefficient, a third dither coefficient and a fourth dither coefficient to four pieces of pixel data respectively corresponding to four adjoining pixels on said screen of said self light-emitting display unit, and alters a combination of said first dither coefficient, said second dither coefficient, said third dither coefficient and said fourth dither coefficient to be respectively added to said four pieces of pixel data for each field of said video signal.