Liquid crystal display device

• US 9,514,693 B2
• Filed: 09/05/2013
• Issued: 12/06/2016
• Est. Priority Date: 09/13/2012
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Yoshida, Takehisa, Shimoshikiryoh, Fumikazu
• Primary Examiner(s): Shankar, Vijay
• Application Number:
  US14/427,314
• Publication Number:
  US 20150221266A1
• Time in Patent Office: 1,188 Days
• Field of Search: 345/89, 345/694
• US Class Current: 1/1
• CPC Class Codes: G02F 1/136259 Repairing; Defects
• CPC Class Codes: G02F 1/136272 Auxiliary lines
• CPC Class Codes: G09G 2300/0413 Details of dummy pixels or dummy lines in flat panels
• CPC Class Codes: G09G 2300/0447 for multi-domain technique to improve the viewing angle in a liquid crystal display, such as multi-vertical alignment [MVA]
• CPC Class Codes: G09G 2300/0804 Sub-multiplexed active matrix panel, i.e. wherein one active driving circuit is used at pixel level for multiple image producing elements
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2320/0223 Compensation for problems related to R-C delay and attenuation in electrodes of matrix panels, e.g. in gate electrodes or on-substrate video signal electrodes
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/028 by changing the viewing angle properties, e.g. widening the viewing angle, adapting the viewing angle to the view direction
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2330/08 Fault-tolerant or redundant circuits, or circuits in which repair of defects is prepared
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/36 using liquid crystals
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3659 the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes
• CPC Class Codes: G09G 3/3685 Details of drivers for data electrodes

Abstract

When a first source bus line (SA) or a second source bus line (SB) which is associated with a pixel of one column is electrically connected with a spare wire (AL1), a control circuit (15B) of a liquid crystal display device (100B) according to an embodiment of the present invention is capable of controlling the amplitudes of the oscillation of a first display signal voltage and a second display signal voltage output to the first source bus line (SA) and the second source bus line (SB) so as to be smaller than that achieved when the first source bus line (SA) or the second source bus line (SB) is not electrically connected with the spare wire (AL1).

Claims

1. A liquid crystal display device, comprising:

a plurality of pixels arranged in a matrix of rows and columns, each of the plurality of pixels including a first sub-pixel and a second sub-pixel;

a first TFT and a second TFT which are associated with each of the plurality of pixels;

a first source bus line connected to the first sub-pixel via the first TFT and a second source bus line connected to the second sub-pixel via the second TFT;

a spare wire which is electrically connectable with the first source bus line and/or the second source bus line; and

a control circuit configured to receive an input display signal that is indicative of grayscale levels which are to be exhibited by the plurality of pixels, generate a first display signal voltage and a second display signal voltage which are to be supplied to the first sub-pixel and the second sub-pixel of each of the plurality of pixels, and output the generated first and second display signal voltages to the first source bus line and the second source bus line, respectively,

wherein when the first source bus line or the second source bus line which is associated with a pixel of one column is electrically connected with the spare wire, the control circuit is capable of controlling amplitudes of oscillation of the first display signal voltage and the second display signal voltage output to the first source bus line and the second source bus line associated with the pixel of the one column so as to be smaller than that achieved when the first source bus line or the second source bus line associated with the pixel of the one column is not electrically connected with the spare wire.

2. The liquid crystal display device of claim 1, wherein when the first source bus line or the second source bus line which is associated with the pixel of the one column is electrically connected with the spare wire, the control circuit is capable of controlling the amplitudes of the oscillation of the first display signal voltage and the second display signal voltage output to the first source bus line and the second source bus line associated with the pixel of the one column so as to be zero.

3. The liquid crystal display device of claim 1, wherein

the plurality of pixels form a plurality of color display pixels, each of the plurality of color display pixels including three or more pixels which exhibit different colors, and

when the first source bus line or the second source bus line which is associated with the pixel of the one column is electrically connected with the spare wire, the control circuit is capable of changing the amplitude of the oscillation of the first display signal voltage or the second display signal voltage according to a color which is to be exhibited by the pixel of the one column.

4. The liquid crystal display device of claim 1, wherein

the plurality of pixels form a plurality of color display pixels, each of the plurality of color display pixels including three or more pixels which exhibit different colors, and

the control circuit is capable of generating a first display signal voltage and a second display signal voltage that are to be supplied to the first sub-pixel and the second sub-pixel of an arbitrary one of the plurality of pixels based on a grayscale level to be exhibited by the arbitrary pixel and grayscale levels to be exhibited by two or more remaining pixels included in a color display pixel to which the arbitrary pixel belongs that are indicated by the input display signal, and outputting the generated first and second display signal voltages to the first source bus line and the second source bus line, respectively.

5. The liquid crystal display device of claim 4, wherein for one grayscale level which is to be exhibited by the arbitrary pixel, the control circuit is capable of generating the first display signal voltage and the second display signal voltage that have two or more different absolute values according to the grayscale levels to be exhibited by the two or more remaining pixels.

6. The liquid crystal display device of claim 4, wherein

the first source bus line and the second source bus line extend in the column direction,

in each of the plurality of pixels, the first sub-pixel and the second sub-pixel are arranged in the column direction, and

a polarity of the first display signal voltage supplied from the first source bus line and a polarity of the second display signal voltage supplied from the second source bus line are each constant within a frame.

7. The liquid crystal display device of claim 6, wherein the polarity of the first display signal voltage supplied from the first source bus line and the polarity of the second display signal voltage supplied from the second source bus line are opposite to each other in a frame.

8. The liquid crystal display device of claim 6, wherein

some of the plurality of pixels which are arranged in the column direction are to exhibit a same color, and

two sub-pixels which belong to two pixels adjacent to each other in the column direction and which are electrically connected to the first source bus line are adjacent to each other in the column direction.

9. The liquid crystal display device of claim 1, wherein the first TFT and the second TFT include a semiconductor oxide layer as an active layer, the semiconductor oxide layer including an In—

Ga—

Zn—

O semiconductor.

10. The liquid crystal display device of claim 9, wherein the In—

Ga—

Zn—

O semiconductor includes a crystalline portion.