Image display method in transmissive-type liquid crystal display device and transmissive-type liquid crystal display device

• US 20020154088A1
• Filed: 04/23/2002
• Published: 10/24/2002
• Est. Priority Date: 04/24/2001
• Status: Active Grant

• Current Assignee: Vista Peak Ventures LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: NEC Corporation
• Inventors: Nishimura, Mitsuhisa
• Granted Patent: US 7,173,599 B2
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G09G 2310/024 Scrolling of light from the illumination source over the display in combination with the scanning of the display screen
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/062 Adjustment of illumination source parameters
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/0653 Controlling or limiting the speed of brightness adjustment of the illumination source
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2320/106 Determination of movement vectors or equivalent parameters within the image
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

A method is provided for displaying an image in a liquid crystal display which enables a scale of a power supply circuit for supplying power to a backlight to be small-sized and the power supply circuit to be low-priced and power consumption of the backlight to be reduced and which enables a flickering phenomenon, a trail-leaving phenomenon (trail-effect), and an image-retention phenomenon to be decreased. In the method for displaying the image in the liquid crystal display device, based on a motion vector, by doing switching between an image signal making up the above image and a blanking signal and by applying a plurality of data electrodes making up the liquid crystal display device, an image signal or a non-image signal is displayed.

Claims

1. A method for displaying an image in a transmissive-type liquid crystal display device comorising a liquid crystal display and a backlight to emit light to said liquid crystal display from a rear of said liquid crystal display, said method comprising:

a step of displaying an image signal or a non-image signal being different from said image signal by doing switching between said image signal and said non-image signal, based on a result from detection of a motion of an image, and by applying said image signal or said non-image signal to a plurality of data electrodes making up said liquid crystal display.

2. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 1, wherein one or a plurality of moving picture parameters is controlled based on said result from detection.

3. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 1, wherein said non-image signal is a signal corresponding to a specified signal level of said image signal.

4. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 1, wherein said non-image signal is a signal corresponding to a specified black signal level of said image signal.

5. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 1, wherein said moving picture parameter comprises at least one of a rate at which said non-image signal is displayed during one frame period, a signal level of said non-image signal, and illumination of said backlight.

6. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 1, wherein said result from detection is a size of a motion vector detected from said image or contained in said image signal.

7. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 1, wherein said result from detection is a size of a fastest motion vector detected from a specified region of said image or contained in said image signal in a specified region of said image.

8. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 2, wherein, in response to said result from detection of a motion of said image, when said image is changed from a still picture to a moving picture, control is exerted so that said moving picture parameter rapidly follows said result from detection and, when said image is changed from a moving picture to a still picture, control is exerted so that said moving picture parameter gently follows said result from detection.

9. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 6, wherein, when a size of said moving picture changes in a direction that said size increases, control is exerted so that a change in said moving picture parameter rapidly follows a size of said motion vector and, when a size of said moving picture changes in a direction that said size decreases, control is exerted so that a change in said moving picture parameter gently follows a size of said motion vector.

10. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 2, wherein, when said result from detection changes to a direction in which control is required so that a rate at which said non-image signal is displayed during one frame period is increased, control is exerted so that a change in said moving picture parameter rapidly follows a size of said motion vector and, when said result from detection changes to a direction in which control is required so that a rate at which said non-image signal is displayed during one frame period is decreased, control is exerted so that a change in said moving picture parameter gently follows a size of said motion vector.

11. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 2, wherein said image signal, after having undergone a gamma correction, is switched to said non-image signal and is applied to said plurality of said data electrodes making up said liquid crystal display and wherein said moving picture parameter includes information about said gamma correction.

12. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 1, wherein display timing with which said non-image signal is displayed on a plurality of main scanning display lines of said liquid crystal display is set in a manner that there is a period of time during which said display timing is overlapped while said non-image signal is displayed on said plurality of said main scanning display lines and wherein said backlight is turned OFF during a period while said display timing is overlapped or during a part of said period while said display timing is overlapped.

13. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 1, wherein display timing with which said non-image signal is displayed on two or more main scanning display lines of said liquid crystal display is set to be different for every two or more main scanning display lines or for every two or more blocks and wherein a part of said backlight corresponding to said two or more main scanning display lines or to said two or more blocks is turned OFF.

14. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 1, wherein display timing of said non-image signal is controlled by timing with which said non-image signal is fed to said plurality of data electrodes.

15. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 1, wherein an image is made up of a plurality of windows and, based on a result from detection of a motion of said image, switching is done between said image signal and said non-image signal for every window and switched signals are fed to a plurality of data electrodes making up said liquid crystal display to display said image signal or said non-image signal.

16. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 15, wherein one or a plurality of moving picture parameters is controlled for every window, based on said result from detection of a motion of said image making up said window or based on said result from detection, a type of said image or a size of said window.

17. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 15, wherein, based on said result from detection of a motion of said image making up said window, when said image is judged to be a moving picture, said image signal and said non-image signal are fed during one frame period to said plurality of data electrodes and, when said image is judged to be a still image, said image signal only is fed during said one frame period two or more times to said plurality of data electrodes.

18. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 16, wherein said moving picture parameter comprises a rate at which said non-image signal is displayed during one frame period, a level of said non-image signal and illumination of said backlight.

19. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 16, wherein said image signal, after having undergone a gamma correction, is switched to said non-image signal and then is applied to said plurality of data electrodes making up said liquid crystal display and wherein said moving picture parameter includes information about said gamma correction.

20. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 16, wherein a specified multiplication coefficient corresponding to said moving picture parameter for said window is multiplied by said image signal making up said window and a result from said multiplication is applied to said plurality of data electrodes.

21. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 20, wherein said multiplication coefficient is a coefficient which reduces a discontinuous change in display luminance caused by a discontinuous change of a rate at which said non-image signal making up said window is displayed during one frame period.

22. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 20, wherein said multiplication coefficient includes information about said gamma correction.

23. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 18, wherein levels of said non-image signals and rates at which said non-image signals are displayed during one frame period are same between a plurality of windows in which said image is respectively judged to be a moving picture.

24. The method for displaying an image in the transmissive-type liquid crystal display device according to claim 18, wherein said plurality of windows in which said image is respectively judged to be a moving picture does not share same main scanning display lines in said transmissive-type liquid crystal display device.

26. The transmissive-type liquid crystal display device according to claim 25, wherein said control circuit, based on said result from detection, controls one or a plurality of moving picture parameters.

27. The transmissive-type liquid crystal display device according to claim 25, wherein said non-image signal is a signal corresponding to a specified signal level of said image signal.

28. The transmissive-type liquid crystal display device according to claim 25, wherein said non-image signal is a signal corresponding to a specified black signal level of said image signal.

29. The transmissive-type liquid crystal display device according to claim 25, wherein said each moving picture parameter is made up of at least one of a rate at which said non-image signal is displayed during one frame period, a signal level of said non-image signal, and illumination of said backlight.

30. The transmissive-type liquid crystal display device according to claim 25, wherein said result from detection is a size of a motion vector detected from said image or contained in said image signal.

31. The transmissive-type liquid crystal display device according to claim 25, wherein said result from detection is a size of a fastest motion vector detected from a specified region of said image or contained in said image signal in a specified region of said image.

32. The transmissive-type liquid crystal display device according to claim 26, wherein said control circuit, in response to a result from detection of a motion of said image, when said image is changed from a still picture to a moving picture, exerts control so that said each moving picture parameter rapidly follows said result from detection and, when said image is changed from a moving picture to a still picture, exerts control so that said each moving picture parameter gently follows said result from detection.

33. The transmissive-type liquid crystal display device according to claim 30, wherein said control circuit, when a size of said moving picture changes in an direction that said size increases, exerts control so that a change in said each moving picture parameter rapidly follows a size of said motion vector and, when a size of said moving picture changes in a direction that said size decreases, exerts control so that a change in said each moving picture parameter gently follows a size of said motion vector.

34. The transmissive-type liquid crystal display device according to claim 26, wherein said control circuit, when said result from detection changes to a direction in which control is required so that a rate at which said non-image signal is displayed during one frame period is increased, exerts control so that a change in said each moving picture parameter rapidly follows a size of said motion vector and, when said result from detection changes to a direction in which control is required so that a rate at which said non-image signal is displayed during one frame period is decreased, exerts control so that a change in said each moving picture parameter gently follows a size of said motion vector.

35. The transmissive-type liquid crystal display device according to claim 26, further comprising a gamma correcting circuit to make a gamma correction to said image signal, wherein said control circuit switches an output signal from said gamma correcting circuit to said non-image signal and feeds it to said plurality of data electrodes making up said liquid crystal display and wherein said moving picture parameter includes information about said gamma correction.

36. The transmissive-type liquid crystal display device according to claim 25, wherein said control circuit sets display timing with which said non-image signal is displayed on a plurality of main scanning display lines of said liquid crystal display in a manner that there is a period of time during which said display timing is overlapped while said non-image signal is displayed on said plurality of said main scanning display lines and wherein said backlight is turned OFF during a period while said display timing is overlapped or during a part of said period while said display timing is overlapped.

37. The transmissive-type liquid crystal display device according to claim 25, wherein said control circuit sets said display timing with which said non-image signal is displayed on two or more main scanning display lines of said liquid crystal display so as to be different for said every two or more main scanning display lines or for every two or more blocks and turns OFF a part of said backlight corresponding to said two or more main scanning display lines or to said two or more blocks.

38. The transmissive-type liquid crystal display device according to claim 25, wherein said control circuit controls said display timing of said non-image signal by timing with which said non-image signal is fed to said plurality of data electrodes.

39. The transmissive-type liquid crystal display device according to claim 25, wherein an image is made up of a plurality of windows and said control circuit, based on said result of detection of a motion of said image, does switching between said image signal and said non-image signal for every window and feeds switched signals to said plurality of data electrodes making up said liquid crystal display to display said image signal or said non-image signal.

40. The transmissive-type liquid crystal display device according to claim 39, wherein, said control circuit controls one or a plurality of moving picture parameters for said every window, based on said result from detection of a motion of said image making up said window or based on said result from detection, a type of said image or a size of said window.

41. The transmissive-type liquid crystal display device according to claim 39, wherein said control circuit, based on said result of detection of a motion of said image making up said window and, when having judged said image to be a moving picture, feeds said image signal and said non-image signal during one frame period to said plurality of data electrodes and, when having judged said image to be a still picture, feeds said image signal only during said one frame period two or more times to said plurality of data electrodes.

42. The transmissive-type liquid crystal display device according to claim 39, wherein said moving picture parameter comprises a rate at which said non-image signal is displayed during one frame period, a level of said non-image signal and illumination of said backlight.

43. The transmissive-type liquid crystal display device according to claim 40, wherein said control circuit, after having made a gamma correction to said image signal, switches said image signal to said non-image signal and then applies it to said plurality of data electrodes making up said liquid crystal display and wherein said moving picture parameter includes information about said gamma correction.

44. The transmissive-type liquid crystal display device according to claim 40, wherein said control circuit multiplies a specified multiplication coefficient corresponding to said moving picture parameter for said window by said image signal making up said window and feeds a result from the multiplication to said plurality of data electrodes.

45. The transmissive-type liquid crystal display device according to claim 44, wherein said multiplication coefficient is a coefficient which reduces a discontinuous change in display luminance caused by a discontinuous change of a rate at which said non-image signal making up said window is displayed during one frame period.

46. The transmissive-type liquid crystal display device according to claim 44, wherein said multiplication coefficient includes information about said gamma correction.

47. The transmissive-type liquid crystal display device according to claim 42, wherein said control circuit sets such that levels of said non-image signals and rates at which said non-image signals are displayed during one frame period are same between a plurality of windows in which said image is respectively judged to be a moving picture.

48. The transmissive-type liquid crystal display device according to claim 42, wherein said plurality of windows in which said image is respectively judged to be a moving picture does not share same main scanning display lines in said liquid crystal display device.

25. A transmissive-type liquid crystal display device comprising a liquid crystal display and a backlight to emit light to said liquid crystal display from a rear of said liquid crystal display, comprising:

a detection circuit to detect a motion of an image; and

a control circuit to display an image signal or said non-image signal by doing switching between said image signal and a non-image signal being different from said image signal, based on a result from detection of a motion of an image and by applying a plurality of data electrodes making up said liquid crystal display.