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

• US 7,554,535 B2
• Filed: 10/03/2002
• Issued: 06/30/2009
• Est. Priority Date: 10/05/2001
• Status: Active Grant

• Current Assignee: NLT Technologies, Ltd.
• Original Assignee: NEC Corporation
• Inventors: Sasaki, Daigo
• Primary Examiner(s): Dharia; Prabodh M
• Application Number:
  US10/491,562
• Publication Number:
  US 20040246242A1
• Time in Patent Office: 2,462 Days
• Field of Search: 345204-215, 345/473, 345/474, 345/619, 345/76, 345102-104, 345 87- 89, 345/211, 345/209, 345/75.2, 345/1.1, 345/98, 345/77, 345/691, 345/699, 345/3.3, 348/441, 348/452, 348/459, 348/157, 250/484.4, 362/561, 382/104, 382/312, 382/128, 382/107
• US Class Current: 345/206
• 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 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, wherein said 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, 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.

2. The display device in accordance with claim 1, 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.

3. The display device in accordance with claim 1, characterized by comprising means for extracting a brightness feature from the input video signal,

the control signal generating section setting the ratio between the image gradation display period to conduct image display for the display and the 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.

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

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

means for extracting mean luminance from the input video signal,

the control signal generating section setting the ratio between the image gradation display period to conduct image display for the display and the 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.

5. The display device in accordance with claim 1, 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.

6. 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, and

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.

7. 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;

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, wherein the wherein 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; 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.

8. 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;

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, wherein the wherein 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; 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.