Color picture display apparatus using hue modification to improve picture quality

• US 6,486,923 B1
• Filed: 01/04/2000
• Issued: 11/26/2002
• Est. Priority Date: 03/26/1999
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Iio, Shinya, Hara, Zenichiro, Okamoto, Takashi, Maeshima, Kazuya
• Primary Examiner(s): Miller, John
• Assistant Examiner(s): Natnael, Paulos M.
• Application Number:
  US09/477,364
• Time in Patent Office: 1,057 Days
• Field of Search: H04/N.967, H04/N.968, H04/N.964, 348/801, 348/802, 348/806, 348/649, 348/725, 348/659, 348/661, 348/660, 345/83, 345/82, 345/589, 345/590-1
• US Class Current: 348/649
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• 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
• CPC Class Codes: G09G 3/2014 by modulation of the duration of a single pulse during which the logic level remains constant
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: H04N 21/4318 by altering the content in the rendering process, e.g. blanking, blurring or masking an image region image enhancement or restoration in general G06T5/00
• CPC Class Codes: H04N 5/58 in dependence upon ambient light
• CPC Class Codes: H04N 9/30 using solid-state colour display devices
• CPC Class Codes: H04N 9/64 Circuits for processing colour signals H04N9/77 takes precedence; camera processing pipelines for processing colour signals H04N23/84

Abstract

A color picture display apparatus employs an array of light-emitting diodes or other light-emitting elements emitting different colors. A television signal is converted to monochromatic signals of the different colors. A color converter modifies the monochromatic signals, thereby changing the displayed hues to match the hues that would be displayed on a television screen, to compensate for ambient lighting conditions, or to achieve other desired effects. If each picture element has only a single light-emitting element, the modification preferably avoids unlit gaps in monochromatic areas of the displayed picture.

Claims

1. A color picture display apparatus, comprising:

first conversion means converting a color television signal to a plurality of monochromatic digital signals representing different colors;

second conversion means coupled to said first conversion means, converting said monochromatic digital signals to modified monochromatic digital signals representing desired hues; and

display means coupled to said second conversion means, displaying a color picture according to said modified monochromatic digital signals, said display-means having a plurality of light-emitting elements disposed in a regular array, each one of said light-emitting elements emitting one of said different colors, wherein substantially all said light-emitting elements emitting one color emit said color when any color is reproduced, other than black, wherein a comparatively large number of said light-emitting elements emit comparatively long-wavelength light.

2. The color picture display apparatus of claim 1, wherein said second conversion means performs a matrix multiplication operation on said monochromatic digital signals.

3. The color picture display apparatus of claim 1, wherein said second conversion means operates according to externally programmable coefficients.

4. The color picture display apparatus of claim 1, wherein said monochromatic digital signals are sampled in said first conversion means at different timings, corresponding to positions of the individual light-emitting elements in said display means.

5. The color picture display apparatus of claim 4, wherein said light-emitting elements are light-emitting diodes.

6. The color picture display apparatus of claim 5, wherein said different colors are red, green, and blue, said display means having more light-emitting diodes emitting red light than light-emitting diodes emitting green light, and more light-emitting diodes emitting red light than light-emitting diodes emitting blue light.

7. The color picture display apparatus of claim 1, wherein substantially all red light-emitting elements are driven when any color is reproduced, other than black.

8. The color picture display apparatus of claim 1, wherein said each one of said light-emitting elements is controlled according to picture data sampled at a different timing.

9. A method of displaying a color picture, comprising the steps of:

(a) converting a color television signal to a plurality of monochromatic digital signals representing different colors;

(b) converting said monochromatic digital signals to modified monochromatic digital signals representing desired hues; and

(c) controlling a regular array of light-emitting elements according to said modified monochromatic digital signals, each one of said light-emitting elements emitting one of said different colors, wherein substantially all said light-emitting elements emitting one color emit said color when any color is reproduced, other than black, wherein a comparatively large number of light-emitting elements emit comparatively long-wavelength light.

10. The method of claim 9, wherein said step (b) performs a matrix multiplication operation on said monochromatic digital signals.

11. The method of claim 9, wherein said step (b) uses externally programmable coefficients.

12. The method of claim 9, wherein said monochromatic digital signals are sampled in said step (a) at different timings, corresponding to positions of the individual light-emitting elements in said regular array.

13. The method of claim 12, wherein said light-emitting elements are light-emitting diodes.

14. The method of claim 13, wherein said different colors are red, green, and blue, said regular array having more light-emitting diodes emitting red light than light-emitting diodes emitting green light, and more light-emitting diodes emitting red light than light-emitting diodes emitting blue light.

15. The method of claim 9, wherein substantially all red light-emitting elements are driven when any color is reproduced, other than black.

16. The method of claim 9, wherein said each one of said light-emitting elements is controlled according to picture data sampled at a different timing.