Crystal display device

• US 20040263495A1
• Filed: 03/19/2004
• Published: 12/30/2004
• Est. Priority Date: 11/09/2001
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Osada, Toshihiko, Toshii, Takashi, Shiomi, Makoto, Sugino, Michiyuki, Kikuchi, Yuji
• Granted Patent: US 7,397,457 B2
• Time in Patent Office: Days
• US Class Current: 345/204
• CPC Class Codes: G09G 2320/02 Improving the quality of display appearance
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 2340/16 Determination of a pixel data signal depending on the signal applied in the previous frame
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

An edge detecting circuit detects whether a particular pixel belongs to an edge by determining whether the differential value of the pixel from the neighboring pixel is equal to or greater than a threshold. Based on the detection result, an emphasis converter stops OS drive when the image of a pixel area is regarded as an edge image in accordance with the detected result of the edge detecting circuit and implements OS drive when the image of a pixel area is not regarded as an edge image. In this way, the edge detecting circuit detects edge portions of the input video, whereby OS drive in the emphasis converter can be controlled so as to be turned on and off.

Claims

1. A liquid crystal display for image display using a liquid crystal display panel, comprising:

an emphasis-converter determining emphasis-converted data for compensating an optical response characteristic of the liquid crystal display panel in accordance with, at least, a gray scale level transition of input image data from a previous vertical period to a current vertical period;

an edge detector detecting an edge portion contained in the input image data; and

a selector selecting either the emphasis-converted data or the input image data, based on a detection result of the edge portion and supplying the selected one as display image data to the liquid crystal display panel.

2. The liquid crystal display according to claim 1, further comprising:

a subtracter for subtracting the input image data from the emphasis-converted data;

a multiplier for multiplying an output signal from the subtracter by a weight coefficient which is variably controlled based on a detection result of the edge portion; and

,

an adder for adding an output signal from the multiplier to the input image data so as to determine the display image data.

3. The liquid crystal display according to claim 1, further comprising:

a conversion table memory storing an emphasis conversion parameter for converting the input image data into the emphasis-converted data; and

a non-conversion table memory storing a non-conversion parameter for outputting the input image data as it is,

wherein the display image data is determined by reference to either the conversion table memory or the non-conversion table memory, by performing selective switching therebetween based on a detection result of the edge portion.

4. The liquid crystal display according to claim 1, further comprising:

a table memory that stores an emphasis conversion parameter for converting the input image data into the emphasis-converted data and a non-conversion parameter for outputting the input image data as it is,

wherein the display image data is determined by reference to either a reference table area holding the emphasis conversion parameter and a reference table area holding the non-conversion parameter, by performing selective switching therebetween based on the detection result of the edge portion.

5. A liquid crystal display for image display using a liquid crystal display panel, comprising:

an emphasis converter for determining emphasis-converted data for input image data for compensating an optical characteristic of the liquid crystal display panel, in accordance with a gray scale level transition from a previous vertical period to a current vertical period;

a noise detector for detecting noise contained in the input image data; and

a selector for selecting either the input image data and the emphasis-converted data, based on a detection result from the noise detector and supplying the selected one to the liquid crystal display panel.

6. The liquid crystal display according to claim 5, wherein the noise detector detects two-dimensional noise based on a correlation between pixels of the input image data with respect to a horizontal direction and a vertical direction.

7. The liquid crystal display according to claim 5, wherein the noise detector detects three-dimensional noise based on a correlation between pixels of the input image data with respect to a horizontal direction and a vertical direction and based on a correlation between pixels of the input image data with respect to a temporal direction.

8. The liquid crystal display according to any one of claims 5 to 7, wherein the emphasis converter includes a table memory storing emphasis conversion parameters for representative gray scale level transition patterns of display data gray scale levels.

9. (Canceled)

10. (Canceled)

11. (Canceled)

12. A liquid crystal display for image display using a liquid crystal display panel, comprising:

an emphasis converter for determining emphasis-converted data for input image data for compensating an optical characteristic of the liquid crystal display panel, in accordance with a gray scale level transition from a previous vertical period to a current vertical period;

a characteristic quantity detector for detecting a characteristic quantity of the input image data; and

a selector for selecting either the emphasis-converted data or the input image data, based on the detected characteristic quantity and supplying the selected one as display image data to the liquid crystal display panel.

13. (Canceled)

14. (Canceled)

15. (Canceled)

16. (Canceled)

17. (Canceled)

18. A liquid crystal display for image display using a liquid crystal display panel, comprising:

a video processor implementing a predetermined video adjustment process for input image data, in accordance with a user'"'"'s video adjustment command; and

a write-gray scale level determining section determining emphasis-converted data for compensating an optical response characteristic of the liquid crystal display panel in accordance with, at least, a gray scale level transition of the input image data from a previous vertical period to a current vertical period,

wherein the write-gray scale level determining section selects either the emphasis-converted data or the input image data, based on the user'"'"'s video adjustment command content and outputs the selected one as display image data to the liquid crystal display panel.

19. The liquid crystal display according to claim 18, wherein the write-gray scale level determining section comprises:

a subtracter for subtracting the input image data from the emphasis-converted data;

a multiplier for multiplying an output signal from the subtracter by a weight coefficient which is selected in accordance with the user'"'"'s video adjustment command content; and

an adder for adding an output signal from the multiplier to the input image signal so as to determine the display image data.

20. The liquid crystal display according to claim 18, wherein the write-gray scale level determining section comprises:

a conversion table memory storing an emphasis conversion parameter for converting the input image data into the emphasis-converted data; and

a non-conversion table memory storing a non-conversion parameter for outputting the input image data as it is, and determines the display image data by reference to either the conversion table memory or the non-conversion table memory, by performing selective switching therebetween based on the user'"'"'s video adjustment command content.

21. The liquid crystal display according to claim 18, wherein the write-gray scale level determining section comprises:

a table memory that stores an emphasis conversion parameter for converting the input image data into the emphasis-converted data and a non-conversion parameter for outputting the input image data as it is, and determines the display image data by reference to either a reference table area holding the emphasis conversion parameter and a reference table area holding the non-conversion parameter, by performing selective switching therebetween based on the user'"'"'s video adjustment command content.

26. The liquid crystal display according to any one of claims 18 to 21, wherein the video processor adjusts a frequency characteristic of the input image data, based on the user'"'"'s video adjustment command.

27. The liquid crystal display according to any one of claims 18 to 21, wherein the video processor adjusts a gray scale level characteristic of the input image data, based on the user'"'"'s video adjustment command.

22. A liquid crystal display for image display using a liquid crystal display panel, comprising:

a video processor for implementing a predetermined video adjustment process for input image data, in accordance with a user'"'"'s video adjustment command; and

a write-gray scale level determining section for determining emphasis-converted data for compensating an optical response characteristic of the liquid crystal display panel in accordance with, at least, a gray scale level transition of the input image data from a previous vertical period to a current vertical period,

wherein the write-gray scale level determining section varies the emphasis-converted data for compensating the optical response characteristic of the liquid crystal display panel based on the user'"'"'s video adjustment command content and supplies the resultant varied emphasis-converted data as display image data to the liquid crystal display panel.

23. The liquid crystal display according to claim 22, wherein the write-gray scale level determining section comprises:

a subtracter for subtracting the input image data from the emphasis-converted data;

a multiplier for multiplying an output signal from the subtracter by a weight coefficient which is variably controlled in accordance with the user'"'"'s video adjustment command content; and

,

an adder for adding an output signal from the multiplier to the input image data so as to determine the display image data.

24. The liquid crystal display according to claim 22, wherein the write-gray scale level determining section comprises:

a plurality of conversion table memories each storing a different emphasis conversion parameter for converting the input image data into the emphasis-converted data, and determines the display image data, by reference to one of the plural conversion table memories, by performing selective switching therebetween based on the user'"'"'s video adjustment command content.

25. The liquid crystal display according to claim 22, wherein the write-gray scale level determining section comprises:

a table memory storing a plurality of reference table areas each holding a different emphasis conversion parameter for converting the input image data into the emphasis-converted data, and determines the display image data, by reference to one of the plurality of reference table areas, by performing selective switching therebetween based on the user'"'"'s video adjustment command content.

53. The liquid crystal display according to any one of claims 22 to 25, wherein the video processor adjusts a frequency characteristic of the input image data, based on the user'"'"'s video adjustment command.

54. The liquid crystal display according to any one of claims 22 to 25, wherein the video processor adjusts a gray scale level characteristic of the input image data, based on the user'"'"'s video adjustment command.

28. A liquid crystal display for image display using a liquid crystal display panel, comprising:

a write-gray scale level determining section which determines emphasis-converted data for compensating an optical response characteristic of the liquid crystal display panel, by implementing emphasis conversion for input image data in accordance with a gray scale level transition from a previous vertical period to a current vertical period and selects either the emphasis-converted data or the input image data, based on a user'"'"'s command to supply the selected one as write-gray scale level data to the liquid crystal display panel.

29. The liquid crystal display according to claim 28, wherein the write-gray scale level determining section comprises:

a conversion table memory storing an emphasis conversion parameter for converting the input image data into the emphasis-converted data that compensates the optical response characteristic of the liquid crystal display panel, in accordance with the gray scale level transition from the previous vertical period to the current vertical period;

a subtracter for subtracting the input image data from the emphasis-converted data determined using the emphasis conversion parameter;

a multiplier for multiplying an output signal from the subtracter by a weight coefficient which is selected in accordance with a user'"'"'s command; and

an adder for adding an output signal from the multiplier to the input image data so as to determine the write-gray scale level data.

30. The liquid crystal display according to claim 28, wherein the write-gray scale level determining section comprises:

a conversion table memory storing an emphasis conversion parameter for converting the input image data into the emphasis-converted data that compensates the optical response characteristic of the liquid crystal display panel, in accordance with the gray scale level transition from the previous vertical period to the current vertical period;

a non-conversion table memory storing a non-conversion parameter for outputting the input image data as it is;

a selector implementing selective switching between the conversion table memory and the non-conversion table memory, in accordance with a user'"'"'s command; and

a write-gray scale level determining portion that determines the write-gray scale level data by reference to either the conversion table memory or the non-conversion table memory, which is selected by the selector.

31. The liquid crystal display according to claim 28, wherein the write-gray scale level determining section comprises:

a table memory storing an emphasis conversion parameter for converting the input image data into the emphasis-converted data that compensates the optical response characteristic of the liquid crystal display panel, in accordance with a gray scale level transition from the previous vertical period to the current vertical period and a non-conversion parameter for outputting the input image data as it is;

a selector implementing selective switching between a reference table area holding the emphasis conversion parameter and a reference table area holding the non-conversion parameter, based on a user'"'"'s command; and

a write-gray scale level determining portion that determines the write-gray scale level data by reference to the reference table area in the table memory, which is selected by the selector.

32. A liquid crystal display for image display using a liquid crystal display panel, comprising:

a write-gray scale level determining section which determines emphasis-converted data for compensating an optical response characteristic of the liquid crystal display panel, by implementing emphasis conversion for input image data in accordance with a gray scale level transition from a previous vertical period to a current vertical period; and

an installed state detector for detecting an installed state of the liquid crystal display,

wherein the write-gray scale level determining section selects either the emphasis-converted data or the input image data based on the detected installed state of the liquid crystal display to supply the selected one as write-gray scale level data to the liquid crystal display panel.

33. The liquid crystal display according to claim 32, wherein the write-gray scale level determining section comprises:

a conversion table memory storing an emphasis conversion parameter for converting the input image data into the emphasis-converted data that compensates the optical response characteristic of the liquid crystal display panel, in accordance with the gray scale level transition from the previous vertical period to the current vertical period;

a subtracter for subtracting the input image data from the emphasis-converted data determined using the emphasis conversion parameter;

a multiplier for multiplying an output signal from the subtracter by a weight coefficient which is selected in accordance with the installed state of the liquid crystal display; and

an adder for adding an output signal from the multiplier to the input image data so as to determine the write-gray scale level data.

34. The liquid crystal display according to claim 32, wherein the write-gray scale level determining section comprises:

a conversion table memory storing an emphasis conversion parameter for converting the input image data into the emphasis-converted data that compensates the optical response characteristic of the liquid crystal display panel, in accordance with the gray scale level transition from the previous vertical period to the current vertical period;

a non-conversion table memory storing a non-conversion parameter for outputting the input image data as it is;

a selector implementing selective switching between the conversion table memory and the non-conversion table memory, in accordance with the installed state of the liquid crystal display; and

a write-gray scale level determining portion that determines the write-gray scale level data by reference to either the conversion table memory or the non-conversion table memory, which is selected by the selector.

35. The liquid crystal display according to claim 32, wherein the write-gray scale level determining section comprises:

a table memory storing an emphasis conversion parameter for converting the input image data into the emphasis-converted data that compensates the optical response characteristic of the liquid crystal display panel, in accordance with the gray scale level transition from the previous vertical period to the current vertical period and a non-conversion parameter for outputting the input image data as it is;

a selector implementing selective switching between a reference table area holding the emphasis conversion parameter and a reference table area holding the non-conversion parameter, based on the installed state of the liquid crystal display; and

a write-gray scale level determining portion that determines the write-gray scale level data by reference to the reference table area in the table memory, which is selected by the selector.

40. The liquid crystal display according to any one of claims 32 to 35, wherein the installed state detector is a vertical inversion sensor for detecting a state of vertical inversion of the liquid crystal display panel.

41. The liquid crystal display according to any one of claims 32 to 35, wherein the installed state detector is an in-plane rotation sensor for detecting an in-plane rotated state of the liquid crystal display panel.

36. A liquid crystal display for image display using a liquid crystal display panel, comprising:

a write-gray scale level determining section which determines emphasis-converted data for compensating an optical response characteristic of the liquid crystal display panel, by implementing emphasis conversion for input image data in accordance with a gray scale level transition from a previous vertical period to a current vertical period; and

an installed state detector detecting an installed state of the liquid crystal display,

wherein the write-gray scale level determining section varies the emphasis-converted data for compensating the optical response characteristic of the liquid crystal display panel based on a detected installed state of the liquid crystal display to supply the resultant varied emphasis-converted data as write-gray scale level data to the liquid crystal display panel.

37. The liquid crystal display according to claim 36, wherein the write-gray scale level determining section comprises:

a conversion table memory storing an emphasis conversion parameter for converting the input image data into the emphasis-converted data that compensates the optical response characteristic of the liquid crystal display panel, in accordance with the gray scale level transition from the previous vertical period to the current vertical period;

a subtracter for subtracting the input image data from the emphasis-converted data determined using the emphasis conversion parameter;

a multiplier for multiplying an output signal from the subtracter by a weight coefficient which is variably controlled in accordance with the installed state of the liquid crystal display; and

an adder for adding an output signal from the multiplier to the input image data so as to determine the write-gray scale level data.

38. The liquid crystal display according to claim 36, wherein the write-gray scale level determining section comprises:

a plurality of conversion table memories each storing a different emphasis conversion parameter for converting the input image data into the emphasis-converted data that compensates the optical response characteristic of the liquid crystal display panel, in accordance with the gray scale level transition from the previous vertical period to the current vertical period;

a selector for selecting one of the plurality of conversion table memories based on the installed state of the liquid crystal display; and

a write-gray scale level determining portion for determining the write-gray scale level data with reference to the conversion table memory selected by the selector.

39. The liquid crystal display according to claim 36, wherein the write-gray scale level determining section comprises:

a table memory having a plurality of reference table areas each holding a different emphasis conversion parameter for converting the input image data into the emphasis-converted data that compensates the optical response characteristic of the liquid crystal display panel, in accordance with the gray scale level transition from the previous vertical period to the current vertical period;

a selector for selecting one of the plurality of reference table areas based on the installed state of the liquid crystal display; and

a write-gray scale level determining portion for determining the write-gray scale level data with reference to the reference table area in the table memory, which is selected by the selector.

55. The liquid crystal display according to any one of claims 36 to 39, wherein the installed state detector is a vertical inversion sensor for detecting a state of vertical inversion of the liquid crystal display panel.

56. The liquid crystal display according to any one of claims 36 to 39, wherein the installed state detector is an in-plane rotation sensor for detecting an in-plane rotated state of the liquid crystal display panel.

42. A liquid crystal display for image display using a liquid crystal display panel, comprising:

an emphasis converter for determining emphasis-converted data for input image data for compensating an optical characteristic of the liquid crystal display panel, in accordance with a gray scale level transition from a previous vertical period to a current vertical period;

a characteristic quantity detector for detecting a high frequency component contained in the input image data as a characteristic quantity of the input image data; and

a controller which variably controls the emphasis-converted data from the emphasis converter, based on the detected characteristic quantity and outputs the resultant controlled emphasis-converted data to the liquid crystal display panel.

43. The liquid crystal display according to claim 42, wherein the characteristic quantity detector detects the high frequency component exceeding a threshold which is variably controlled in accordance with a video adjustment command for the input image data.

44. The liquid crystal display according to claim 42, wherein the characteristic quantity detector detects the high frequency component exceeding a threshold which is variably controlled in accordance with an encoding parameter of the input image data.

45. The liquid crystal display according to any one of claims 42 to 44, further comprising a multiplier for multiplying the emphasis-converted data by a weight coefficient, wherein the controller reduces the resultant controlled emphasis-converted data by variably controlling a value of the coefficient in accordance with the characteristic quantity and outputs the resultant reduced controlled emphasis-converted data to the liquid crystal display panel.

46. The liquid crystal display according to any one of claims 42 to 44, further comprising:

a subtracter for subtracting the input image data from the emphasis-converted data;

a multiplier for multiplying an output signal from the subtracter by a weight coefficient; and

an adder for adding an output signal from the multiplier to the input image data to output the sum to the liquid crystal display panel,

wherein the controller reduces the resultant controlled emphasis-converted data by variably controlling a value of the weight coefficient in accordance with the characteristic quantity and outputs the resultant reduced controlled emphasis-converted data to the liquid crystal display panel.

47. The liquid crystal display according to any one of claims 42 to 44, further comprising a table memory storing a plurality of different emphasis conversion parameters,

wherein the emphasis converter determines the emphasis-converted data based on the emphasis conversion parameters stored in the table memory, and the controller reduces the resultant controlled emphasis-converted data by selecting the emphasis conversion parameters to which the emphasis converter refers, in accordance with the characteristic quantity and outputs the resultant reduced controlled emphasis-converted data to the liquid crystal display panel.

48. A liquid crystal display for image display using a liquid crystal display panel, comprising:

an emphasis converter for determining emphasis-converted data for input image data for compensating an optical characteristic of the liquid crystal display panel, in accordance with a gray scale level transition from a previous vertical period to a current vertical period;

a characteristic quantity detector for detecting a differential value between a plurality of pixels in the input image data, as a characteristic quantity of the input image data; and

a controller which variably controls the emphasis-converted data from the emphasis converter, in accordance with the detected characteristic quantity and outputs the resultant controlled emphasis-converted data to the liquid crystal display panel.

49. The liquid crystal display according to claims 48, wherein the characteristic quantity detector detects the differential value between the plurality of pixels exceeding a threshold which is variably controlled in accordance with an encoding parameter of the input image data.

50. The liquid crystal display according to claims 48 or 49, further comprising a multiplier for multiplying the emphasis-converted data by a weight coefficient, wherein the controller reduces the resultant controlled emphasis-converted data by variably controlling a value of the weight coefficient in accordance with the characteristic quantity and outputs the resultant reduced controlled emphasis-converted data to the liquid crystal display panel.

51. The liquid crystal display according to claims 48 or 49, further comprising:

a subtracter for subtracting the input image data from the emphasis-converted data;

a multiplier for multiplying an output signal from the subtracter by a weight coefficient; and

an adder for adding an output signal from the multiplier to the input image data to output the sum to the liquid crystal display panel,

wherein the controller reduces the resultant controlled emphasis-converted data by variably controlling a value of the coefficient in accordance with the characteristic quantity and outputs the resultant reduced controlled emphasis-converted data to the liquid crystal display panel.

52. The liquid crystal display according to claims 48 or 49, further comprising:

a table memory storing a plurality of different emphasis conversion parameters, wherein the emphasis converter determines the emphasis-converted data based on the emphasis conversion parameters stored in the table memory, wherein the controller reduces the resultant controlled emphasis-converted data by selecting the emphasis conversion parameters to which the emphasis converter refers, in accordance with the characteristic quantity and outputs the resultant reduced controlled emphasis-converted data to the liquid crystal display panel.