Color display control apparatus for controlling display gray scale of each scanning frame or each plurality of dots

• US 5,552,800 A
• Filed: 08/23/1994
• Issued: 09/03/1996
• Est. Priority Date: 08/09/1990
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Shimamoto, Hajime, Uchikoga, Hiroshi, Zenda, Hiroki
• Primary Examiner(s): SARAS, STEVEN J
• Application Number:
  US08/294,614
• Time in Patent Office: 742 Days
• Field of Search: 345/1, 345/3, 345/88, 345/89, 345/98, 345/147-155
• US Class Current: 345/89
• CPC Class Codes: G06F 3/1475 with conversion of CRT control signals to flat panel control signals, e.g. adapting the palette memory
• CPC Class Codes: G09G 3/2025 the sub-frames having all the same time duration
• CPC Class Codes: G09G 3/2051 with use of a spatial dither pattern
• CPC Class Codes: G09G 3/2055 the pattern being varied in time
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

According to this invention, a panel controller converts display data having 64 gray scale levels for a color CRT output from an RAMDAC into display data having 57 gray scale levels to perform display driving of a color LCD. The panel display controller has a function of generating 7 intermediate pseudo gray scales between the base frames of R, G, and B signals by a frame rate control method in the color LCD having 8 base gray scale levels of each of the R, G, and B signals to generate (180K colors) display data having 57 gray scale levels and a function of generating 3 intermediate pseudo gray scales between the base gray scales of the signals by a dither method to generate (24K colors) display data having 39 gray scale levels. The selection of the frame rate control or the dither method and the selection of the 512-color, 180-K-color, or 24-K-color display are arbitrarily performed, or these selection operations are automatically performed in accordance with a display mode.

Claims

1. A color panel display control system for a display screen having a plurality of dots, the column panel display control system comprising:

a color panel display device having a predetermined number of gray scale levels for each of specified primary colors;

a CRT controller for outputting display data representing the primary colors and display timing signals to control the color panel display device;

RAMDAC means for converting the display data output from the CRT controller into R-, G-, and B-data; and

color panel display controller means having;

means for receiving the R-, G-, and B-data from the RAMDAC means, for generating each of R-, G-, and B-base gray-scale data and each of R-, G- and B-next gray-scale data from the received R-, G-, and B-data, wherein the R-, G-, and B-base gray-scale data and the R-, G- and B-next gray-scale data are predetermined by voltage levels associated with the dots of the display screen, and for generating a frame rate duty cycle from a vertical sync signal, dot pattern data from a horizontal sync signal and a dot clock signal; and

frame rate control means for displaying intermediate gray-scale levels between the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data by selectively providing, using a number of the frame rate duty cycle and the dot pattern data, the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data on a certain dot of the display screen.

2. A system according to claim 1, wherein said color panel display control means includes means for scanning a scanning frame odd-numbered times.

3. A color panel display control system for a display screen having a plurality of dots, the color panel display control system comprising:

a color panel display device having a predetermined number of gray scale levels for each of specified primary colors;

a CRT controller for outputting display data representing the primary colors and display timing signals to control the color panel display device;

RAMDAC means for converting the display data output from the CRT controller into R-, G-, and B-data; and

color panel display controller means having;

means for receiving the R-, G-, and B- data from the RAMDAC means, for generating each of R-, G-, and B-base gray-scale data and each of R-, G-, and B-next gray-scale data from the received R-, G-, and B-data, wherein the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data are predetermined by voltage levels associated with the dots of the display screen, and for generating a frame rate duty cycle from a vertical sync signal, dot pattern data from a horizontal sync signal and a dot clock signal;

means for dividing a frame into a predetermined number of matrices, one matrix per pixel being constituted by a plurality of dots; and

dither means for displaying intermediate gray scale levels between the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data by selectively providing., using the dot pattern data, the base gray-scale data and the R-, G-, and B-next gray-scale data on each of dots in accordance with the dot pattern data.

4. A color panel display control system for a display screen having a plurality of dots, the color panel display control system comprising:

a color panel display device having a number of predetermined gray scales for each of specified primary colors;

a CRT controller for outputting display data representing the primary colors and display timing signals to control the color panel display device;

RAMDAC means for converting the display data output from the CRT controller into R-, G-, and B-data; and

color panel display controller means having;

means for receiving the R-, G-, and B-data from the RAMDAC means, for generating each of R-, G-, and B-base gray-scale data and each of R-, G-, and B-next gray-scale data from the received R-, G-, and B-data, wherein the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data are predetermined by voltage levels associated with the dots of the display screen, and for generating a frame rate duty cycle from a vertical sync signal, dot pattern data from a horizontal sync signal and a dot clock signal;

frame rate control means for displaying intermediate gray-scale levels between the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data by selectively providing, using a number of the frame rate duty cycle and the dot pattern data, the R-, G-, and B-base gray-scale data and the R-, G- and B-next gray-scale data on a certain dot of the display screen;

means for dividing a frame into a predetermined number of matrices, one matrix per pixel being constituted by a plurality of dots;

dither means for displaying intermediate gray scale levels between the R-, G-, and B-base gray-scale data and the R-, G- and B-next gray-scale data by selectively providing, using the dot pattern data, the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data on each of dots in accordance with the dot pattern data; and

means for selecting one of the frame rate control means and the dither means in accordance with a display frame mode.

5. A system according to claim 4, wherein said selecting means includes means for arbitrarily selecting one of the FRC means and the dither means.

6. A system according to claim 4, wherein said selecting means includes means for automatically selecting one of the the FRC means and the dither means in accordance with a display frame mode.

7. A system according to claim 4, wherein said color panel display control means includes means for scanning a scanning frame odd-numbered times.

8. A color panel display control system for a display screen having a plurality of dots, the color panel display control system comprising:

a color panel display device having a predetermined number of gray scale levels for each of specified primary colors;

a CRT controller for outputting display data representing the primary colors and display timing signals to control the color panel display device;

RAMDAC means for converting the display data output from the CRT controller into R-, G-, and B-data of 6 bits each; and

color panel display controller means having;

means for receiving the R-, G-, and B-data from the RAMDAC means, for generating each of R-, G-, and B-base grayscale data and each of R-, G-, and B-next gray-scale data from the received R-, G-, and B-data, wherein the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data are predetermined by voltage levels associated with the dots of the display screen, and for generating a frame rate duty cycle from a vertical sync signal, dot pattern data from a horizontal sync signal and a dot clock signal;

frame rate control means for displaying intermediate gray-scale levels between the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data by selectively providing, using a number of the frame rate duty cycle and the dot pattern data, the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data on a certain dot of the display screen;

means for dividing a frame into a predetermined number of matrices, one matrix per pixel being constituted by a plurality of dots;

dither means for displaying intermediate gray scale levels between the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data by selectively providing, using the dot pattern data, the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data on each of dots in accordance with the dot pattern data;

first generating means for generating first display color data in the predetermined gray scale;

second generating means for generating second display color data using one of the frame rate control means and the dither means; and

switching means for performing a switching operation between the first and the second generating means.

9. A system according to claim 8, wherein said switching means includes means for arbitrarily selecting one of said first generating means and said second generating means.

10. A system according to claim 8, wherein said switching means includes means for automatically selecting one of said first generating means and said second generating means in accordance with a display frame mode.

11. A system according to claim 8, wherein said color panel display control means includes means for scanning a scanning frame odd-numbered times.

12. A color panel display control system for a display screen having a plurality of dots, the color panel display control system comprising:

a color panel display device having a predetermined number of gray-scale levels for each of specified primary colors;

a CRT controller for outputting display data representing the primary colors and display timing signals to control the color panel display device;

RAMDAC means for converting the display data output from the CRT controller into R-, G-, and B-data; and

color panel display controller means having;

means for receiving the R-, G-, and B- data from the RAMDAC means, for generating each of R-, G-, and B-base gray-scale data and each of R-, G-, and B-next gray-scale data from the received R-, G-, and B-data, wherein the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data are predetermined by voltage levels associated with the dots of the display screen, and for generating a frame rate duty cycle from a vertical sync signal, dot pattern data from a horizontal sync signal and a dot clock signal;

frame rate control means for displaying intermediate gray-scale levels between the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data by selectively providing, using a number of the frame rate duty cycle and the dot pattern data, the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data on a certain dot of the display screen by the frame rate duty cycle;

dividing means for dividing a frame into a predetermined number of matrices, one matrix per pixel being constituted by a plurality of dots; and

dither means for displaying intermediate gray scale levels between the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data by selectively providing, using the dot pattern data, the R-, G-, and B-base gray-scale data and the R-, G-, and B-next gray-scale data on each of dots in accordance with the dot pattern data.

13. The system according to claim 12, wherein the color panel display control means generates each of the R-, G-, and B- next gray-scale data of the R-, G-, and B-base gray-scale data from substantially the upper bits of the R-, G-, and B-data.

14. The system according to claim 12, further comprising an arithmetic circuit for performing a predetermined calculation on the basis of the upper and lower bits of each of the R-, G-, and B-data to generate each of R-, G-, and B-next gray-scale data of the R-, G-, and B-base gray-scale data and for generating pattern address data in accordance with the predetermined calculation, and for selecting one of the R-, G-, and B-base gray-scale data and the next R-, G-, and B-gray-scale data from the pattern address data and the dot pattern data and a number of the frame rate duty cycle.

15. The system according to claim 12, wherein the color panel display control means further comprises means for automatically selecting one of the FRC means and the dither means in accordance with a display frame mode.