Apparatus and method for gray scale display

• US 5,119,086 A
• Filed: 06/14/1989
• Issued: 06/02/1992
• Est. Priority Date: 06/18/1988
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd., Hitachi Video Engineering Incorporated
• Original Assignee: Hitachi, Ltd., Hitachi Video Engineering Incorporated
• Inventors: Tsuchiya, Nobuo, Mano, Hiroyuki, Nishioka, Kiyokazu
• Primary Examiner(s): Oberley, Alvin E.
• Assistant Examiner(s): Wu, Xiao M.
• Application Number:
  US07/366,163
• Time in Patent Office: 1,084 Days
• Field of Search: 340/793, 340/703, 358/79, 358/455, 358/81, 358/80
• US Class Current: 345/690
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 5/028 Circuits for converting colour display signals into monochrome display signals

Abstract

Disclosed is a system selecting one out of a plurality of gray scale signals for each color information in display information including color information of a plurality of colors for providing monochromatic gray scale signals at multiple levels corresponding to the display information, or, when multiple colors are produced by combining a plurality of colors, selecting one out of a plurality of gray scales for each color corresponding to gray scales of the multiple colors, to thereby attain a multi-level monochromatic emulation display.

Claims

1. An apparatus for gray scale display comprising:

display memory means for storing display information, including color information for colors formed by combining a plurality of colors;

gray scale signal generating means for generating a plurality of gray scale signals for a predetermined color corresponding to one of the colors represented by the color information;

gray scale selecting means responsive to receipt of the plurality of gray scale signals for the predetermined color from said gray scale signal generating means for selecting one of the gray scale signals for the predetermined color;

means for controlling the gray scale corresponding to each of the plurality of colors to obtain a specific display contrast; and

video signal generating means for generating a video signal corresponding with the gray scale signal selected by said selecting means.

2. The apparatus for gray scale display according to claim 1, wherein:

said gray scale signal generating means includes means for generating gray scale signals of a number larger than the number of colors represented by the color information; and

said gray scale selecting means includes means for selecting any of the gray scale signals for each of the colors.

3. The apparatus for gray scale display according to claim 1, further comprising display means coupled to said video signal generating means for displaying the video display represented by the generated video signal.

4. A method for gray scale display comprising the steps of:

storing display information, including color information for colors formed by combining a plurality of colors;

generating a plurality of gray scale signals for a predetermined color corresponding to one of the colors represented by the color information;

selecting one of the plurality of gray scale signals for the predetermined color;

controlling the selected gray scale signal of the predetermined color to obtain a specific display contrast; and

displaying the controlled gray scale signal.

5. The method for gray scale display according to claim 4, wherein:

the gray scale signal generating step includes generating gray scale signals of a number larger than the number of colors represented by the color information; and

the gray scale signal selecting step includes selecting any of the gray scale signals for each of the colors.