Display apparatus, image display system, and terminal using the same

• US 20040246242A1
• Filed: 04/02/2004
• Published: 12/09/2004
• Est. Priority Date: 10/05/2001
• Status: Active Grant

• Current Assignee: NLT Technologies, Ltd.
• Original Assignee: NEC Corporation
• Inventors: Sasaki, Daigo
• Granted Patent: US 7,554,535 B2
• Time in Patent Office: Days
• US Class Current: 345/204
• 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 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• 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 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/103 Detection of image changes, e.g. determination of an index representative of the image change
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• 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 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

In a display, the reduction in brightness which is a problem of the mobile picture improving method in a black reset scheme is reduced to a minimum value and a clear image is displayed.

The display includes a movement amount extracting unit 42 to extract an amount of movement from a time series image signal and a ratio setting unit 43 to set a first period (image gradation display period) to conduct image display on the display element and a second period (black reset period) to display black image thereon according to the extracted amount of movement.

Claims

1. A display device, characterized by comprising:

a display element for sequentially converting a time series image signal into image display light and for displaying an image;

movement amount extracting means for extracting an amount of movement from the time series image signal; and

ratio setting means for setting a first period to conduct image display on the display element and a second period to display black image thereon according to the amount of movement thus extracted.

5. The display device in accordance with claim 1, characterized in that:

the time series image signal is an encoded digital signal including movement vector information; and

the movement amount extracting means extracts the movement vector information from the time series image signal.

6. The display device in accordance with claim 1, wherein:

the movement amount extracting means extracts an amount of movement according to an image signal of at least a previous frame of the time series image signal and an image signal of a current frame.

7. The display device in accordance with claim 1, characterized in that:

the ratio setting means sets the ratio between the first and second periods when a feature of brightness of the time series image signal makes a change which is larger than a beforehand set value by a predetermined value.

8. The display device in accordance with claim 1, characterized by comprising gradation correcting means for correcting gradation of the time series image signal according to the extraction quantity resultant from the extraction.

9. The display device in accordance with claim 1, characterized in that the display element is a display element of a type other than the light emitting type, the display device comprising:

a backlight divided into a plurality of subareas at least in a scanning direction of a display panel; and

a control circuit for controlling on and off of the backlight subareas in an independent fashion, the control circuit turning the backlight on during a first period and turning the backlight off during the second period.

10. The display device in accordance with claim 9, characterized by further comprising a control circuit for controlling brightness of the backlight, wherein

the control circuit controls the brightness of the backlight according to either one of the amount of movement and the feature of brightness or according to both of the amount of movement and the feature or brightness.

11. The display device in accordance with claim 1, characterized by comprising:

an optical shutter divided into a plurality of subareas in a scanning direction of a display panel; and

a control circuit to conduct light transmission control and light interruption control for the optical shutter subareas in an independent manner,

the control circuit setting the optical shutter to a light transmission state during the first period and setting the optical shutter to a light interruption state during the second period.

12. The display device in accordance with claim 1, characterized by comprising:

a plurality of optical shutters rotating in a scanning direction of a display panel; and

a control circuit for conducting rotation and phase control for the optical shutters in an independent fashion,

the control circuit controlling the optical shutters such that a light transmitting zone of the optical shutter is effective during the first period and a light interrupting zone of the optical shutter is effective during the second period.

13. The display device in accordance with claim 12, characterized by comprising an integrator between the optical shutters and a light source.

14. The display device in accordance with claim 13, characterized in that the light interrupting zone of each of the optical shutters includes a light reflecting characteristic.

15. The display device in accordance with claim 11, characterized by comprising a control circuit for controlling brightness of a light source of the display device,

the control circuit controlling the brightness of a light source according to either one of the amount of movement and the feature of brightness or according to both of the amount of movement and the feature of brightness.

16. The display device in accordance with claim 1, characterized in that a black reset signal is inputted to the display element at a start point of the second period.

34. The terminal device including a display device in accordance with claim 1.

35. The terminal device including an image processing system in accordance with claim 1.

2. A display device, characterized by comprising:

a display element for sequentially converting a time series image signal into image display light and for displaying an image;

movement amount extracting means for extracting an amount of movement from the time series image signal;

brightness feature extracting means for extracting a feature of brightness from the time series image signal; and

setting means for setting a ratio between the first period to conduct image display on the display element and the second period to display black image thereon according to the amount of movement thus extracted and the feature of brightness thus extracted.

3. A display device, characterized by comprising:

a display element for sequentially converting a time series image signal into image display light and for displaying an image;

movement amount extracting means for extracting an amount of movement from the time series image signal;

mean luminance extracting means for extracting mean luminance from the time series image signal; and

setting means for setting a ratio between the first period to conduct image display on the display element and the second period to display black image thereon according to the amount of movement thus extracted and the mean luminance thus extracted.

4. A display device, characterized by comprising:

a display element for sequentially converting a time series image signal into image display light and for displaying an image;

movement amount extracting means for extracting an amount of movement from the time series image signal;

mean luminance extracting means for extracting mean luminance from the time series image signal;

maximum luminance extracting means for extracting maximum luminance from the time series image signal; and

setting means for setting a ratio between the first period to conduct image display on the display element and the second period to display black image thereon according to the amount of movement extracted, the means luminance, and the maximum luminance thus extracted.

17. A display device, characterized by comprising:

a display section including

a display panel including a plurality of pixels arranged in a matrix form at intersections at which a plurality of scanning lines and a plurality of signal lines intersect each other,

a scanning line driving circuit for conducting sequential driving control for the scanning lines, and

a signal line driving circuit for conducting driving control for the signal lines according to an input video signal; and

a lighting section disposed on a rear surface side of the display section,

the lighting section including

a plurality of lighting devices divided into subareas in a direction parallel to the scanning lines sequentially driven in the display section,

a light driving section for controlling on and off of the lighting devices in an independent manner,

a control signal generating section for sending a control signal to the light driving section according to an input video signal and a control signal, and

an image memory for storing a video signal, the light driving section generating a control signal to control on and off timing of each of the lighting devices of the lighting section according to the input video signal, a video signal of a frame preceding a current frame and being stored in the image memory, and the control signal and sending the control signal to the light driving section.

18. The display device in accordance with claim 17, characterized in that the control signal generator conducts control such that when writing starts in pixels corresponding to a scanning line at a first edge of a partition of the display section corresponding to one of the lighting devices, the lighting device is turned off and when a response of pixels corresponding to a scanning line at a last edge of the partition is finished, the lighting device is turned on.

20. The display device in accordance with claim 17, characterized by comprising a gradation correcting section for correcting gradation of the input video signal according to the control signal controlling the on and off timing of the lighting device,

the video signal of which gradation is corrected by the gradation correcting section being supplied to the signal line driving circuit.

27. The display device in accordance with claim 17, characterized in that the control signal generating section sets a ratio between an image gradation display period to conduct image display for the display and a black reset period to display black image therefor according to the amount of movement extracted from the input video signal and the video signal in the image memory.

28. The display device in accordance with claim 17, characterized by comprising means for extracting a brightness feature from the input video signal,

the control signal generating section setting a ratio between an image gradation display period to conduct image display for the display and a black reset period to display black image therefor according to the amount of movement extracted from the input video signal and the video signal in the image memory, and the brightness feature of the input video signal.

29. The display device in accordance with claim 17, characterized by comprising:

means for extracting a brightness feature from the input video signal; and

means for extracting means luminance from the input video signal,

the control signal generating section setting a ratio between an image gradation display period to conduct image display for the display and a black reset period to display black image therefor according to the amount of movement extracted from the input video signal and the video signal in the image memory, the brightness feature of the input video signal, and the mean luminance thereof.

19. A display device, characterized by comprising:

a display section including

a display panel including a plurality of pixels arranged in a matrix form at intersections at which a plurality of scanning lines and a plurality of signal lines intersect each other,

a scanning line driving circuit for conducting sequential driving control for the scanning lines, and

a signal line driving circuit for conducting driving control for the signal lines according to an input video signal; and

a lighting section disposed on a rear surface side of the display section, the lighting section including

a plurality of lighting devices divided into subareas in a direction parallel to the scanning lines sequentially driven in the display section,

a light driving section for controlling on and off of the lighting devices in an independent manner,

a control signal generating section for sending a control signal to the light driving section, and

a decoding circuit for decoding an encoded input video signal,

the control signal generating section inputting movement vector information obtained by the decoding circuit, generating a control signal to control on and off timing of each of the lighting devices of the lighting section according to an amount of movement, and delivering the control signal thus generated to the light driving section.

30. The display device in accordance with claim 19, characterized in that

the control signal generating section setting a ratio between an image gradation display period to conduct image display for the display and a black reset period to display black image therefor according to the input video signal and the amount of movement.

21. A display device, characterized by comprising:

a display section including

a display panel including a plurality of pixels arranged in a matrix form at intersections at which a plurality of scanning lines and a plurality of signal lines intersect each other,

a scanning line driving circuit for conducting sequential driving control for the scanning lines, and

a signal line driving circuit for conducting driving control for the signal lines according to an input video signal; and

a lighting section disposed on a rear surface side of the display section, the display device further comprising;

an optical shutter in front of the lighting section and the display section or in front of the display section,

the optical shutter being divided into a plurality of subareas in a scanning direction of the display section;

an optical shutter control section for controlling the optical shutter subareas in an independent fashion,

the optical shutter conducting light interruption for a black reset period during one frame period and conducting light transmission during an image gradation display period;

a control signal generating section for sending a control signal to the optical shutter control section according to the input video signal and the control signal; and

an image memory for storing a video signal,

the control signal generating section generating a control signal to control transmitting and interrupting timing of the optical shutter according to the input video signal, a video signal of a frame preceding a current frame stored in the image frame, and a control signal inputted thereto, and outputting the control signal thus generated to the optical shutter control section.

25. The display device in accordance with claim 21, characterized by comprising a gradation correcting section for correcting gradation of the input video signal,

the video signal of which gradation is corrected by the gradation correcting section being supplied to the signal line driving circuit.

26. The display device in accordance with claim 25, characterized in that the gradation correcting section corrects gradation of the input video signal according to an amount of movement of an image or according to mean luminance and an amount of movement of an image.

22. A display device, characterized by comprising:

a display section including

a display panel including a plurality of pixels arranged in a matrix form at intersections at which a plurality of scanning lines and a plurality of signal lines intersect each other,

a scanning line driving circuit for conducting sequential driving control for the scanning lines, and

a signal line driving circuit for conducting driving control for the signal lines according to an input video signal; and

a lighting section disposed on a rear surface side of the display section, the display device further comprising;

an image memory for storing a video signal; and

a control signal generating section for generating a black reset period setting signal to control setting of a black period according to a video signal of a frame preceding a current frame stored in the image frame and a control signal and outputting the black reset period setting signal to the scanning line driving circuit,

the lighting section being turned on fully at a time,

an image gradation display pulse and a black reset display pulse being inputted to each of the scanning lines once during one frame period.

23. The display device in accordance with claim 22, characterized in that in a configuration including one signal line for each pixel, image gradation writing and black reset writing are conducted for each line during one line selection period.

24. The display device in accordance with claim 22, characterized in that in a configuration including two signal lines for each pixel, a voltage corresponding to an image gradation signal and a voltage corresponding to a black reset signal are applied to the respective signal lines, and either one thereof is respectively selected during an image gradation display period and a black reset period.

31. An image processing system, characterized by comprising:

movement amount extracting means for extracting an amount of movement from a time series image signal; and

ratio setting means for setting a first period to conduct image display on a display element and a second period to display black image thereon according to the amount of movement thus extracted.

33. The image display system in accordance with claim 31, characterized by comprising gradation correcting means for correcting gradation of the time series image signal according to the amount of movement thus extracted or the feature of brightness thus extracted.

32. An image processing system, characterized by comprising:

movement amount extracting means for extracting an amount of movement from a time series image signal;

brightness feature extracting means for extracting a feature of brightness from the time series image signal; and

setting means for setting a ratio between a first period to conduct image display on the display element and the second period to display black image thereon according to the amount of movement thus extracted and the feature of brightness thus extracted.