Color display apparatus

• US 5,334,996 A
• Filed: 10/23/1990
• Issued: 08/02/1994
• Est. Priority Date: 12/28/1989
• Status: Expired due to Fees

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Kobayashi, Yoshiharu, Satoh, Yoshikazu, Tanigaki, Yasushi
• Primary Examiner(s): Weldon, Ulysses
• Assistant Examiner(s): Liang, Regina
• Application Number:
  US07/603,974
• Time in Patent Office: 1,379 Days
• Field of Search: 340/701, 340/703, 340/730, 340/728, 340/735, 340/750, 340/748, 345/150, 345/152, 345/141, 345/143, 345/136, 345/186, 345/192
• US Class Current: 345/694
• CPC Class Codes: G09G 2340/0457 Improvement of perceived resolution by subpixel rendering
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127
• CPC Class Codes: G09G 5/24 Generation of individual character patterns

Abstract

A color display apparatus which stores the color information of characters to be displayed in three storage planes (4R, 4C, 4B) of a character generator so that this information can be used in a display controller (21) in such a way that high-quality characters are displayed on a display panel. The information is stored so that different sequences of 3-bit color dots can be displayed.

Claims

1. A color display apparatus comprising:

a color display panel containing a plurality of color dots of equal size and comprising three primary colors formed in a predetermined order in which the color dots of each primary color are respectively aligned in vertical columns on the display panel, a memory for storing bit information corresponding to dot-matrix patterns representative of characters to be displayed, and a display control section for activating the color dots on the color display panel in accordance with the bit information read from the memory to thereby display characters, characterized in that the memory is provided with at least three storage areas corresponding respectively to color-dot groups of the three primary colors, in that each storage area stores bit information corresponding to dot-matrix patterns representative respectively of a plurality of characters to be displayed, wherein to display a character, the display control section activates the color dots of the three primary colors on the color display panel based respectively on data read respectively from said three storage areas and in a manner such that the three primary color dots for a slant segment of the character are activated in a sequence different from the activation sequence of the three primary color dots of a non-slant segment of the character displayed on the color display panel.

2. A color display apparatus according to claim 1, characterized in that the display panel comprises a liquid crystal device.

3. A color display apparatus comprising:

a color display device containing a plurality of color dots comprising three primary colors arranged in rows and columns with the color dots of each primary color respectively aligned in columns,

an input for supplying to the display apparatus a video signal with character data,

a memory device for storing binary bit information corresponding to dot-matrix patterns representing characters to be displayed on the color display device, said memory device comprising at least three storage areas corresponding respectively to color-dot groups of the three primary colors and with each storage area storing bit information corresponding to dot-matrix patterns of the characters to be displayed in a manner whereby, read-out of said bit information defines one or more display pixels in one or more color dot rows of the display device, wherein each display pixel in a row includes three adjacent color dots activated in a color dot sequence that is not fixed and which is determined by a character to be displayed, and

a display control device coupled to said input and to said memory device for activating the color dots of the three primary colors of the color display device in accordance with three bit information groups read out from the respective three storage areas of the memory device.

4. A color display apparatus as claimed in claim 3, wherein the three primary colors are red, green and blue and said characters bit information are stored in said three storage areas of the memory device in dot-matrix patterns such that one or more certain selected display pixels can comprise three color bits in any one of the three following sequences, red green and blue;

green, blue and red; and

blue, red and green.

5. A color display apparatus as claimed in claim 3, wherein the memory device comprises three planes of storage one storage plane for each primary color, and with bit patterns for certain selected display pixels shifted with respect to bit patterns for other display pixels.

6. A color display apparatus as claimed in claim 3, further comprising;

a video RAM coupled to said memory device and to said display control device for the temporary storage of three-bit color dot patterns read out from the memory device under control of the display control device, and

a display controller coupled to the color display device and to the video RAM and controlled by said display control device to activate the display pixels of the color display device in accordance with the stored character information.

7. A color display apparatus as claimed in claim 3, wherein the color display device comprises a liquid crystal display panel and said color dots sequence of said display pixel in any given row of the display panel is dependent on the character to be displayed.

8. A color display apparatus as claimed in claim 4 wherein the display control device activates the three primary color dots in a slant segment of a displayed character, as determined by the dot-matrix patterns of character bit information stored in said three storage areas of the memory device, in a sequence other than the sequence for a non-slant segment whereby a character with a relatively smooth slant segment is displayed on the color display device.

9. A color display apparatus as claimed in claim 3 wherein all of the color dots in the color display device are of equal size.

10. A color display apparatus as claimed in claim 5 wherein display pixels on slant segments of a displayed character are of equal size to display pixels of non-slant segments of the displayed character.

11. A color display apparatus as claimed in claim 3 wherein said display control device activates at least one color dot of a slant segment of a displayed character which is in vertical alignment with a corresponding activated color dot of a non-slant segment of the displayed character.

12. A color display apparatus as claimed in claim 11 wherein the color display device comprises a liquid display panel.

13. A color display apparatus as claimed in claim 3 wherein certain selected display pixels comprise pixels forming slant segments of a displayed character.

14. A color display apparatus as claimed in claim 13 wherein at least one of said certain selected display pixels in one row is shifted less than three color dots along the row with respect to the color dots of an adjacent certain selected pixel in an adjacent row of the displayed character.

15. A color display apparatus as claimed in claim 3 wherein certain selected display pixels comprise pixels forming slant segments of a displayed character in which first and second certain selected display pixels of a slant segment in successive rows of the color display device are offset in the row direction such that they are partly in alignment in the column direction.

16. A color display apparatus comprising:

a color display device containing a plurality of color dots made up of three primary colors arranged in rows and columns with the color dots of each primary color aligned in columns,

an input for supplying to the display apparatus a video signal with character data,

a memory device for storing binary bit information corresponding to dot-matrix patterns representing characters to be displayed on the color display device, said memory device comprising at least three storage areas corresponding respectively to color dot groups of the three primary colors and with each storage area storing bit information corresponding to dot-matrix patterns of the characters to be displayed in a manner whereby, upon read-out of said bit information, selected display pixels include three color dots activated in a sequence determined by a character to be displayed, and

a display control device coupled to said input and to said memory device for activating the color dots of the three primary colors of the color display device in accordance with the patterns of character bit information stored in said three storage areas of the memory device so that the three primary color dots in a slant segment of a displayed character are activated in a sequence different from other segments of the displayed character whereby said displayed character with a relatively smooth slant segment is displayed on the color display device.

17. A color display apparatus as claimed in claim 16 wherein each selected display pixel includes three adjacent activated color dots.

18. A color display apparatus as claimed in claim 16 wherein first and second selected display pixels in successive rows of the color display device making up said slant segment are offset in the row direction so that they are in partial alignment.

19. A color display apparatus as claimed in claim 16 wherein the color display device comprises a liquid crystal display panel.

20. A color display apparatus comprising:

a color display device including a plurality of color dots of three primary colors which are arranged in rows and columns with the color dots of each primary color vertically aligned in columns,

a signal input for character data,

a memory device for storing binary bit information corresponding to dot-matrix patterns representing characters to be displayed on the color display device, said memory device comprising at least three storage areas corresponding respectively to color-dot groups of the three primary colors and with each storage area storing bit information corresponding to dot-matrix patterns of the characters to be displayed in a manner such that display pixels in a row comprise three primary color dots which are activated in different sequences determined by said characters to be displayed such that a color dots sequence of a display pixel within a row is not fixed but is determined by said characters to be displayed, and

a display control device coupled to said signal input and to said memory device for activating the color dots of the three primary colors of the color display device in accordance with the dot-matrix patterns of character bit information stored in said three storage areas of the memory device.