Computer display system controller

• US 6,002,385 A
• Filed: 03/13/1995
• Issued: 12/14/1999
• Est. Priority Date: 03/11/1994
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Mengistu, Amare
• Application Number:
  US08/402,497
• Time in Patent Office: 1,737 Days
• Field of Search: 345/89, 345/147, 345/152, 345/204, 345/100
• US Class Current: 345/100
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2340/0457 Improvement of perceived resolution by subpixel rendering
• CPC Class Codes: G09G 2370/045 using multiple communication channels, e.g. parallel and serial
• CPC Class Codes: G09G 3/2051 with use of a spatial dither pattern
• CPC Class Codes: G09G 3/2074 using sub-pixels
• 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 3/364 with use of subpixels
• CPC Class Codes: G09G 3/3681 suitable for passive matrices only
• CPC Class Codes: G09G 3/3692 suitable for passive matrices only
• 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: G09G 5/393 Arrangements for updating the contents of the bit-mapped memory
• CPC Class Codes: G09G 5/395 Arrangements specially adapted for transferring the contents of the bit-mapped memory to the screen G09G5/399 takes precedence
• CPC Class Codes: G09G 5/42 characterised by the display of patterns using a display memory without fixed position correspondence between the display memory contents and the display position on the screen

Abstract

There is disclosed a system (45, 55) for controlling a high resolution color discrete level display device, wherein the display device can have multiple common lines (80, 81, 82) for each line of pixels. A frame buffer controller system (45) is disclosed which is adapted to utilise the multiple common lines in a number of different modes, producing a number of different output speeds for the display. Means (126, 127) are also disclosed for dithering the pixel data in accordance with the output modes. Further, the system is capable of displaying images, such as fonts or the like, at an increased resolution than that which would otherwise be possible.

Claims

1. A computer work station comprising:

a computation and data manipulation unit including means for the creation and manipulation of color images, said computation and data manipulation unit being connected to a frame buffering means and being adapted to store images in said frame buffering means;

said frame buffering means comprising a frame buffer storage means for the storage of images and a frame buffer controller means connected to said computation and data manipulation unit and also connected to a high resolution discrete level display device;

said high resolution discrete level display device including a plurality of color pixels which are arranged in an array of substantially parallel display lines, with each color pixel having a plurality of common drive lines and a plurality of data drive lines, and each color pixel being individually settable to a plurality of different states through the intersection of said data drive lines and said common drive lines, wherein said plurality of common drive lines of a line of pixels is capable of being driven in a number of different modes;

wherein images created or manipulated by said computation and data manipulation unit which are to be displayed on said high resolution discrete level display device are stored in said frame buffer and subsequently displayed on said high resolution display device;

means for detecting how many display lines require updating by monitoring display line data as it is read from said frame buffer; and

means for updating said display lines in a faster mode when the number of lines to be updated exceeds a predetermined threshold number, wherein said faster mode comprises driving a predetermined number of said common drive lines of each color pixel simultaneously, and wherein said common drive lines of each color pixel are driven independently from one another in another mode.

2. A computer work station as claimed in claim 1, wherein said frame buffering means includes means for determining a driving mode for said line of color pixels.

3. A computer work station as claimed in claim 2, wherein each color pixel has three common drive lines.

4. A computer work station as claimed in claim 1 wherein said frame buffer controller means includes a region fill engine adapted to fill regions of said frame buffer with colour information, said regions being defined by addresses generated by said computation and data manipulation unit.

5. A computer work station as claimed in claim 1 wherein said frame buffer controller means includes an image fill engine adapted to fill regions of said frame buffer with image information, said regions being defined by addresses generated by said computation and data manipulation unit.

6. A computer work station as claimed in claim 1 wherein said frame buffer controller means includes a fine line drawing means adapted to draw lines in said frame buffer from a first point to a second point, said points being generated by said computation and manipulation unit.

7. A computer work station as claimed in claim 1 wherein said frame buffer stores dithered image data.

8. A computer work station as claimed in claim 7 wherein said frame buffer controller means dithers said image data before storing said dithered image data in said frame buffer.

9. A computer work station as claimed in claim 7 wherein said frame buffer controller means further includes means for further dithering said dithered image data before forwarding it to said high resolution discrete level display device.

10. A computer work station as claimed in claim 1, wherein said high resolution discrete level display device further includes a panel controller means connected to said frame buffer controller means and said frame buffer controller reads current line display information from said frame buffer and forms current line display data packets containing line location data, line pixel data and display mode driving information, said mode information determining which of said plurality of common lines of each said color pixel are to be simultaneously driven to display said line pixel data.

11. A computer Fork station as claimed in claim 1 wherein said high resolution discrete level display device further comprises odd and even pixel data drivers for the driving of odd and even pixel data of a line of pixels of the display;

and

a data distribution unit connected to said frame buffering means and to said odd and even pixel data drivers to receive pixel data from said frame buffering means and to distribute odd pixel data to said odd pixel data driver and even pixel data to said even pixel data driver.

12. A computer workstation as claimed in claim 1 wherein said display device has a memory characteristic and said frame buffer controller means further comprises:

frame buffer input means for inputting display update information to a frame buffer in which said image is stored;

line update detection means connected with said input means for detecting those lines of said image on which said update information occurs; and

update controller means, connected to said frame buffer to receive line data therefrom and connected to said line update detection means to receive update line identification data therefrom and adapted to update only said those lines of said displayed image on said discrete level display with said line data of said those lines.

13. A computer work station as claimed in claim 12 wherein said update controller means from time to time refreshes other lines on which no update information has been detected.

14. A computer work station as claimed in claim 12 wherein said faster mode includes dithering of said update display information.

15. A computer work station as claimed in claim 12 wherein said update controller means includes common line determination means for determining whether the information to be displayed by a combination of said common lines is the same.

16. A computer work station means as claimed in claim 15 wherein said update controller means includes combination drive means for driving said combination of said common lines simultaneously when said common line determination means detects said same combination.

17. A computer work station as claimed in claim 12 wherein said common line determination means determines if all the common lines are to display the same information.

18. A computer work station as claimed in claim 12 wherein said frame store input means includes dither value determination means for determining dither values for storing in said frame buffer.

19. A computer work station as claimed in claim 1, wherein said color pixels comprises a plurality of independently alterable luminance areas, and said frame buffer includes storage portions corresponding to the current state of each independently alterable luminance areas.

20. A computer work station as claimed in claim 1 wherein said frame buffer input means includes direct value transfer means for storing in said frame buffer said storage portions.

21. A computer work station as claimed in claim 1, wherein said display device includes a multiplicity of color pixels arranged on lines, each color pixel being individually settable to a plurality of different states through the intersection of data drive lines and common drive lines, with each line of pixels having a number of common lines, and said display device further comprising a panel display controller comprising:

display packet input means adapted to receive inputted line pixel data packets from said frame buffer means comprising pixel data for a line of pixels, line location data for determination of a currently active line of said display, and mode data information for determination of the mode in which to drive said currently active line of said display;

a plurality of pixel display data line drivers, connected to said display packet input means, said pixel display data line drivers receiving said pixel data from said input means and forwarding said pixel data to corresponding data drive lines for the setting of each pixel on a line;

common line driver decoder means connected to said display packet input means to decode a corresponding active common line driver and a corresponding active common line from said line location data and to activate one of a plurality of common line driver means; and

a plurality of common line driver means connected to said input means and to said common line driver decoder means, each of said common line driver means, upon activation from said common line driver decoder means driving one of a number of lines of pixels, wherein said mode data information determines if some or all of said common lines are driven independently or simultaneously.

22. A computer work station as claimed in claim 21, wherein said pixel data occurs before said mode data in said line pixel data packet.

23. A computer work station as claimed in claim 21, wherein said line pixel data packet further includes synchronisation data and said display packet input means includes synchronisation data detection means for detection of said synchronisation data and synchronisation of the reception of said inputted line pixel data packet.

24. A computer work station as claimed in claim 23 wherein said inputted line pixel data packets can be decomposed into a plurality of data units and said synchronisation data includes a unique data unit.

25. A computer work station as claimed in claim 240 wherein said synchronisation data comprises the repetition of the same said unique data unit.

26. A display device comprising a display having a plurality of pixels and driver means for driving said display, wherein each of said plurality of pixels has a plurality of common drive lines, wherein said driver means includes a common driver being capable of driving at least two common drive lines of said plurality of common drive lines in each pixel independently from each other and wherein said plurality of common drive lines are driven simultaneously when the number of lines to be updated exceeds a predetermined threshold number, each pixel being individually settable to a plurality of different states through the intersection of data drive lines and said common drive lines, wherein said plurality of common drive lines of a line of pixels is capable of being driven in a number of different modes.

27. A display device according to claim 26, wherein each of said plurality of pixels has three common drive lines, wherein said three common drive lines are driven simultaneously in said certain mode and wherein, in a second mode, two of said three common drive lines are driven simultaneously while the common drive line other than said two common drive lines is driven independently from said two common drive lines.

28. A display device according to claim 27, wherein the number of gradation levels being able to be displayed in said second mode is larger than the number of gradation levels being able to be displayed in said certain mode.

29. A display device according to claim 28, wherein the number of gradation levels being able to be displayed in said second mode is 16 and the number of gradation levels being able to be displayed in said certain mode is 4.

30. A display device according to claim 26, wherein each of said plurality of pixels has three common drive lines, wherein said three common drive lines are driven simultaneously in said certain mode and wherein said three common drive lines are driven independently from one another in a second mode.

31. A display device according to claim 30, wherein the number of gradation levels being able to be displayed in said second mode is smaller than the number of gradation levels being able to be displayed in said certain mode.

32. A display device according to claim 31, wherein the number of gradation levels in said second mode is 2 and the number of gradation levels being able to be displayed in said certain modes is 4.

33. A display device according to claim 26, wherein each of said plurality of pixels has three common drive lines, wherein said three common drive lines are driven simultaneously in said certain mode, wherein two of said three common drive lines are driven simultaneously while the common drive line other than said two common drive lines is driven independently from said two common drive lines in a second mode and wherein said three common drive lines are driven independently from one another in a third mode.

34. A display device according to claim 33, wherein the numbers of gradation levels being able to be displayed in said certain, second and third modes are different from one another.

35. A display device according to claim 34, wherein the number of gradation levels being able to be displayed in said certain mode is 4, the number of gradation levels being able to be displayed in said second mode is 16 and the number of gradation levels in said third mode is 2.

36. A display device according to claim 26, wherein each of said plurality of pixels has three common drive lines, wherein two of said three common drive lines are driven simultaneously while the common drive lines other than said two common drive lines are driven independently from said two common drive lines and wherein, in a second mode, said three common drive lines are driven independently from one another.

37. A display device according to claim 36, wherein the number of gradation levels being able to be displayed in said certain mode is larger than the number of gradation levels being able to be displayed in said a second mode.

38. A display device according to claim 37, wherein the number of gradation levels being able to be displayed in said certain mode is 16 and the number of gradation levels being able to be displayed in said second mode is 2.

39. A display device according to claim 26, wherein each of said plurality of pixels has a plurality of data drive lines, each of said plurality of data drive lines being able to be driven independently, and wherein said certain mode is selected when the same data is consecutively inputted in the data drive line.

40. A display device according to claim 26, wherein each of said plurality of pixels includes a plurality of sub-pixels being different from one another in area and wherein at best two of said plurality of sub-pixels are situated on the same common drive line while at least another two of said plurality of sub-pixels are situated on the common drive line other than said common drive line.

41. A display device according to claim 26, wherein each of said plurality of pixels has three common drive lines, wherein said three common drive lines are driven simultaneously in said certain mode and wherein, in another mode, two of said three common drive lines which are not adjacent to each other are driven simultaneously while the remaining common drive line being situated between said two common drive lines is driven independently from said two common drive lines.

42. A display device according to claim 26, wherein each of said plurality of pixels has three common drive lines, wherein said three common drive lines are driven simultaneously in said certain mode and wherein, in another mode, two of said three common drive lines corresponding to two sub-pixels which are not adjacent to each other are driven simultaneously while the remaining common drive line corresponding to another sub-pixel being situated between said hero sub-pixels is driven independently from said two common drive lines.

43. A display device according to claim 26, wherein each of said plurality of pixels is either a red pixel, a green pixel or a blue pixel and wherein said display is able to perform color display.

44. A display device according to claim 26, wherein said certain mode is selected when the number of lines of which data is updated becomes larger than a predetermined number.

45. A computer work station comprising:

a computation and data manipulation unit including means for the creation and manipulation of images, said computation and data manipulation unit being connected to a frame buffering means and being adapted to store images in said frame buffering means;

said frame buffering means comprising a frame buffer storage means for the storage of images and a frame buffer controller means connected to said computation and data manipulation unit and also connected to a high resolution discrete level display device;

said high resolution discrete level display device including a plurality of pixels which are arranged in an array of substantially parallel display lines, with each pixel in a line having a plurality of common drive lines;

wherein images created or manipulated by said computation and data manipulation unit which are to be displayed on said high resolution discrete level display device are stored in said frame buffer and subsequently displayed on said high resolution display device;

means for detecting how many display lines require updating by monitoring display line data as it is read from said frame buffer; and

means for updating said display lines in a faster mode when the number of lines to be updated exceeds a predetermined threshold number, wherein said faster mode comprises driving a predetermined number of said common drive lines of each color pixel simultaneously, and wherein said common drive lines of each color pixel are driven independently,

wherein each pixel is individually settable to a plurality of different states through the intersection of dam drive lines and common drive lines, with each line of pixels having a number of common lines, and said display device further comprising a panel display controller comprising;

display packet input means adapted to receive inputted line pixel data packets from said frame buffer means comprising pixel data for a line of pixels, line location data for determination of a currently active line of said display, and mode data information for determination of the mode in which to drive said currently active line of said display,

a plurality of pixel display data line drivers, connected to said display packet input means, said pixel display data line drivers receiving said pixel data from said input means and forwarding said pixel data to corresponding data drive lines for the setting of each pixel on a line;

common line driver decoder means connected to said display packet input means to decode a corresponding active common line driver and a corresponding active common line from said line location data and to activate one of a plurality of common line driver means; and

a plurality of common line driver means connected to said input means and to said common line driver decoder means, each of said common line driver means, upon activation from said common line driver decoder means driving one of a number of lines of pixels, wherein said mode data information determines if some or all of said common lines are driven independently or simultaneously.

46. A computer work station as claimed in claim 45, wherein said pixel data occurs before said mode data in said line data packet.

47. A computer work station as claimed in claim 45, wherein said line pixel data packet further includes synchronisation data and said display packet input means includes synchronisation data detection means for detection of said synchronisation data and synchronisation of the reception of said inputted line pixel data packet.

48. A computer work station as claimed in claim 47 wherein said inputted line pixel data packets can be decomposed into a plurality of data units and said synchronisation data includes a unique data unit.

49. A computer work station as claimed in claim 48 wherein said synchronisation data comprises the repetition of the same said unique data units from one another in another mode.