IMAGE DISPLAY APPARATUS AND IMAGE DISPLAY METHOD

• US 20110007050A1
• Filed: 09/08/2010
• Published: 01/13/2011
• Est. Priority Date: 06/08/2000
• Status: Abandoned Application

• Current Assignee: Ichiro Sato, Katsuhiko Kumagawa, Katsuyuki Arimoto, Kazuo Inoue, Taro Funamoto, Wataru Machidori
• Original Assignee: Ichiro Sato, Katsuhiko Kumagawa, Katsuyuki Arimoto, Kazuo Inoue, Taro Funamoto, Wataru Machidori
• Inventors: KUMAGAWA, Katsuhiko, MACHIDORI, Wataru, ARIMOTO, Katsuyuki, FUNAMOTO, Taro, SATO, Ichiro, INOUE, Kazuo
• Application Number:
  US12/877,352
• Publication Number:
  US 20110007050A1
• Time in Patent Office: Days
• US Class Current: 345/209
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2202/42 Materials having a particular dielectric constant
• CPC Class Codes: G09G 2300/0434 Flat panel display in which a field is applied parallel to the display plane
• CPC Class Codes: G09G 2320/02 Improving the quality of display appearance
• CPC Class Codes: G09G 2320/0257 Reduction of after-image effects
• 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 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

When displaying moving images by using liquid crystal panels and others, a problem exists in that tail streaks occur, and image degradation is resultantly caused. To solve this problem, an echo suppression circuit divides a video signal into a pair composed of two successive frames for comparison between these two frames in signal level for the purpose of suppressing an echo phenomenon occurring when a liquid crystal panel displays video signals including moving images. If these two frames are not the same in signal level, the signal is accordingly corrected so as to equalize the signal level of these frames. Based on the video signals and others corrected by the echo suppression circuit, a controller operates the liquid crystal panel with AC drive through a source driver and a gate driver. As such, the drive voltage used to operate the liquid crystal panel with AC drive is adjusted so as to be balanced between positive and negative. In this manner, the tail streaks are prevented when displaying moving images.

Claims

1-24. -24. (canceled)

25. A liquid crystal display apparatus for displaying an image based on an input video signal, said liquid crystal display apparatus comprising:

a display device for outputting image lights according to a voltage to be applied; and

a drive unit for driving said display device by switching a drive voltage applied across a pixel liquid crystal between positive and negative for application based on the input video signal, wherein

said drive unit is operable to drive said display device by dividing one vertical scanning period of the input video signal into a first sub period and a second sub period, and

said drive unit is operable to output the input video signal in the first sub period, and output a compensation signal in the second sub period.

26. The liquid crystal display apparatus according to claim 25, wherein the second sub period is shorter than the first sub period.

27. The liquid crystal display apparatus according to claim 25, wherein the drive voltage in the second sub period is a voltage of a pedestal level or lower when said display device is a normally black type, and is a voltage of the pedestal level or higher when said display device is a normally white type.

28. The liquid crystal display apparatus according to claim 25, wherein said display device is a normally black type, and the drive voltage in said second sub period is OV.

29. The liquid crystal display apparatus according to claim 25, wherein the drive voltage in the second sub period is applied to a plurality of scanning lines at one time.

30. An image display method for displaying an image by driving a display device based on an input video signal, said method comprising:

driving the display device by switching a drive voltage applied across a pixel liquid crystal between positive and negative for application based on the input video signal, and by dividing one vertical scanning period of the input video signal into a first sub period and a second sub period, wherein

said driving includes outputting the input video signal in the first sub period, and outputting a compensation signal in the second sub period.