Apparatus and method to improve quality of moving image displayed on liquid crystal display device

• US 8,421,742 B2
• Filed: 05/18/2010
• Issued: 04/16/2013
• Est. Priority Date: 10/13/1999
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Yoshida, Hidefumi, Tanuma, Seiji, Mayama, Takatoshi, Inoue, Yuichi, Suzuki, Toshiaki, Hanaoka, Kazutaka, Gotoh, Takeshi, Kobayashi, Tetsuya, Ohashi, Makoto, Yamaguchi, Hisashi, Tanaka, Katsunori, Katagawa, Koichi
• Primary Examiner(s): DINH, DUC Q
• Application Number:
  US12/782,480
• Publication Number:
  US 20100225681A1
• Time in Patent Office: 1,064 Days
• Field of Search: 345 87-103, 345/204, 345/690, 345/211, 348/701, 348/415.1, 348/411.1, 348/412.1, 349/62, 349/69, 349/70, 315/149, 315307-308, 313/498
• 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 2310/04 Partial updating of the display screen
• CPC Class Codes: G09G 2310/062 Waveforms for resetting a plurality of scan lines at a time
• CPC Class Codes: G09G 2310/063 Waveforms for resetting the whole screen at once
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0238 Improving the black level
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• 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 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 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3666 with the matrix divided into sections

Abstract

A liquid crystal display device includes a panel having pixel electrodes arranged at intersections of a plurality of signal lines via switching elements for transmitting display data and a plurality of scanning lines for transmitting control signals, and a control circuit for controlling the panel. The liquid crystal panel is divided into first pixel regions and second pixel regions adjacent to the first pixel regions. The control circuit carries out impulse driving in which the control signals transmitted to each of the scanning lines are activated two times in one frame period for displaying an image. The control circuit writes the display data in either one of the pixel regions and writes reset data in the other pixel regions when the control signals are activated once of the two times. By writing the reset data in the pixel regions, the display data written in an immediately preceding frame are reset. In consecutive frames, the display data written in the pixel regions are always reset in one frame period. Therefore, blurring in a moving image can be alleviated. Since writing the display data and the reset data is carried out separately in the first pixel regions and in the second pixel regions, flicker is prevented from occurring in a display screen.

Claims

1. A liquid crystal display device comprising:

a liquid crystal panel in which a plurality of signal lines for transmitting display data and a plurality of scanning lines for transmitting control signals are laid out vertically and horizontally, and liquid crystal cells are arranged at intersections of the signal lines and the scanning lines; and

a backlight system facing said liquid crystal panel, and wherein;

driving in which said scanning lines are sequentially scanned while said backlight system is turned on and off, and said display data are written in said liquid crystal cells is carried out; and

said display data written in said liquid crystal cells within a predetermined time before and after said backlight system is turned off during each frame period are estimated data generated by carrying out motion compensation by divided pixel regions, the estimated data being display data displayed at the pixel regions when said backlight system is turned on during a next frame period after a current frame period.

2. A liquid crystal display device according to claim 1, wherein said motion compensation is carried out by using display data in a current frame and in a next frame.

4. A liquid crystal display device according to claim 1, wherein said motion compensation is carried out by using display data in a current frame and in a next frame.

5. A liquid crystal display device according to claim 1, wherein said motion compensation is carried out by divided pixel regions.

6. A liquid crystal display device according to claim 1, wherein, in the driving, said scanning lines are sequentially scanned while said backlight system is turned on during a head period and turned off during a sequent tail period in a frame period.

7. A liquid crystal display device according to claim 6, wherein the predetermined time is from an intermediate point of the head period to an end of the frame period.

8. A liquid crystal display device according to claim 1, wherein if said display data are written in said liquid crystal cells within a predetermined time before and after said backlight system is turned off, said display data are estimated data generated by carrying out motion compensation by divided pixel regions, otherwise said display data are written without being based on estimated data generated by carrying out motion compensation.

3. A liquid crystal display device comprising:

a liquid crystal panel in which a plurality of signal lines for transmitting display data and a plurality of scanning lines for transmitting control signals are laid out vertically and horizontally, and liquid crystal cells are arranged at intersections of the signal lines and the scanning lines; and

a backlight system facing said liquid crystal panel, said backlight system being divided into a plurality of luminescent parts, and wherein;

driving in which said scanning lines are sequentially scanned while changing brightness of said backlight system, and said display data are written in said liquid crystal cells is carried out; and

said display data written in said liquid crystal cells within a predetermined time before and after brightness of said backlight system changes darkly during each frame period are estimated data generated by carrying out motion compensation, the estimated data being display data displayed at the pixel regions when brightness of said backlight system changes brightly during a next frame period after a current frame period.

9. A liquid crystal display device according to claim 3, wherein if said display data are written in said liquid crystal cells within a predetermined time before and after brightness of said backlight system changes, said display data are estimated data generated by carrying out motion compensation, otherwise said display data are written without being based on estimated data generated by carrying out motion compensation.

10. A liquid crystal display device comprising:

a liquid crystal panel in which a plurality of signal lines for transmitting display data and a plurality of scanning lines for transmitting control signals are laid out vertically and horizontally, and liquid crystal cells are arranged at intersections of the signal lines and the scanning lines; and

a backlight system facing said liquid crystal panel, and wherein;

driving in which said scanning lines are sequentially scanned while said backlight system is turned on and off, and said display data are written in said liquid crystal cells is carried out; and

if said display data are written in said liquid crystal cells within a predetermined time before and after said backlight system is turned off, said display data are estimated data generated by carrying out motion compensation by divided pixel regions, when said backlight system is turned on, otherwise said display data are written without being based on estimated data generated by carrying out motion compensation.

11. A liquid crystal display device according to claim 10, wherein said motion compensation is carried out by using display data in a current frame and in a next frame.

12. A liquid crystal display device comprising:

a liquid crystal panel in which a plurality of signal lines for transmitting display data and a plurality of scanning lines for transmitting control signals are laid out vertically and horizontally, and liquid crystal cells are arranged at intersections of the signal lines and the scanning lines; and

a backlight system facing said liquid crystal panel, said backlight system being divided into a plurality of luminescent parts, and wherein;

driving in which said scanning lines are sequentially scanned while changing brightness of said backlight system, and said display data are written in said liquid crystal cells is carried out; and

if said display data are written in said liquid crystal cells within a predetermined time before and after brightness of said backlight system changes, said display data are estimated data generated by carrying out motion compensation, otherwise said display data are written without being based on estimated data generated by carrying out motion compensation.

13. A liquid crystal display device according to claim 12, wherein said motion compensation is carried out by using display data in a current frame and in a next frame.

14. A liquid crystal display device according to claim 12, wherein said motion compensation is carried out by divided pixel regions.