Liquid crystal display device and display defect correction method

• US 9,076,395 B2
• Filed: 06/02/2011
• Issued: 07/07/2015
• Est. Priority Date: 06/02/2010
• 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: Shohraku, Akihiro, Matsuda, Masahiro, Nakagawa, Hidetoshi, Ohishi, Takuya, Yagi, Toshifumi, Kubota, Tomofumi, Miyamoto, Kazushige, Suzuki, Haruhisa
• Primary Examiner(s): Zhou, Hong
• Application Number:
  US13/700,508
• Publication Number:
  US 20130070003A1
• Time in Patent Office: 1,496 Days
• Field of Search: 345/694, 345/209, 345 87-100, 345/690, 349/37, 349/54, 349 79- 80, 349/97, 349/108, 349138-139, 349/147, 349/149, 349/192
• US Class Current: 1/1
• CPC Class Codes: G02F 1/136272 Auxiliary lines
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2330/10 Dealing with defective pixels
• CPC Class Codes: G09G 2330/12 Test circuits or failure detection circuits included in a display system, as permanent part thereof
• 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 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A liquid crystal display device (100) according to the present invention includes a plurality of pixels arrayed in a matrix, n number of the pixels (n is an even number of 4 or greater) being included in a color display pixel (CP). The liquid crystal display device includes an active matrix substrate (10) including a plurality of scanning lines (12) extending in a row direction and a plurality of signal lines (13) extending in a column direction; and a signal line driving circuit (3) that supplies, as a display signal, a gray scale voltage of a positive or negative polarity to each of the plurality of signal lines. The plurality of signal lines include a first type of signal line (13a) which does not intersect another signal line, and a second type of signal line (13b) which intersects a signal line adjacent thereto outside a display area in the state where an insulating film (16) is interposed therebetween. The active matrix substrate further includes a correction line (40) which is provided in the vicinity of an intersection region (IR) where the second type of signal line intersects the adjacent signal line, is electrically separated from the plurality of signal lines, and is at a floating potential.

Claims

1. A liquid crystal display device, comprising a plurality of pixels arrayed in a matrix including a plurality of rows and a plurality of columns, n number of the pixels (n is an even number of 4 or greater) being included in each of color display pixels, the liquid crystal display device comprising:

an active matrix substrate including a plurality of scanning lines extending in a row direction and a plurality of signal lines extending in a column direction; and

a signal line driving circuit that supplies, as a display signal, a gray scale voltage of a positive or negative polarity to each of the plurality of signal lines;

wherein;

the n number of pixels are arrayed in p rows by q columns (p is an integer of 1 or greater, and q is an even number of n or smaller) in each of the color display pixels;

the plurality of signal lines include a first type of signal line which does not intersect another signal line, and a second type of signal line which intersects a signal line adjacent thereto outside a display area in a state where an insulating film is interposed therebetween;

the active matrix substrate further includes a correction line which is provided in the vicinity of an intersection region where the second type of signal line intersects the adjacent signal line, is electrically separated from the plurality of signal lines, and is at a floating potential;

the correction line is provided so as to partially overlap the second type of signal line as seen in a direction normal to the substrate;

the correction line is formed of a conductive film same as that of a part of the plurality of scanning lines which is located in the display area or formed of a conductive film same as that of a part of the plurality of signal lines which is located in the display area;

the correction line includes a first correction line portion defined by one of a pair of the second type of signal lines that intersect with each other that is made from a source metal layer and a second correction line portion defined by another one of the pair of the second type of signal lines that intersect with each other that is made from a gate metal layer;

each of the plurality of signal lines which is outside of the display area includes a lower layer line made of the gate metal layer and an upper layer line made of the source metal layer; and

the first correction line portion partially overlaps the lower layer line and the second correction line portion partially overlaps the upper layer line.

2. The liquid crystal display device of claim 1, wherein the active matrix substrate further includes a marker that points to the correction line.

3. The liquid crystal display device of claim 2, wherein:

the active matrix substrate includes a thin film transistor provided in each of the plurality of pixels; and

the marker is formed of the conductive film same as that of the part of the plurality of scanning lines which is located in the display area, formed of the conductive film same as that of the part of the plurality of signal lines which is located in the display area, or formed of a semiconductor film same as that of a semiconductor layer of the thin film transistor.

4. The liquid crystal display device of claim 1, wherein the n number of pixels included in one of any two color display pixels adjacent to each other in the row direction are each supplied with a gray scale voltage via the first type of signal line, and the n number of pixels included in the other of the any two color display pixels are each supplied with a gray scale voltage via the second type of signal line.

5. The liquid crystal display device of claim 1, wherein the plurality of pixels are arrayed such that the q number of pixels, among the n number of pixels included in the color display pixels arrayed in the row direction, are repeated in the same order.

6. The liquid crystal display device of claim 1, wherein:

the signal line driving circuit includes a plurality of output terminals arrayed in the row direction; and

any two output terminals adjacent to each other, among the plurality of output terminals, output gray scale voltages of opposite polarities to each other.

7. The liquid crystal display device of claim 1, wherein in any two color display pixels adjacent to each other in the row direction, the pixels for displaying the same color are supplied with gray scale voltages of opposite polarities to each other via the signal lines corresponding thereto.

8. The liquid crystal display device of claim 1, wherein any two pixels adjacent to each other in the row direction in each of the color display pixels are supplied with gray scale voltages of opposite polarities to each other via the signal lines corresponding thereto.

9. The liquid crystal display device of claim 1, wherein the n number of pixels included in each of the color display pixels display different colors from each other.

10. The liquid crystal display device of claim 1, wherein the n number of pixels included in each of the color display pixels include a red pixel for displaying red, a green pixel for displaying green, a blue pixel for displaying blue, and a yellow pixel for displaying yellow.

11. A display fault correction method for correcting a display fault in the liquid crystal display device of claim 1, the method comprising:

step (A) of specifying, from the plurality of signal lines, the second type of signal line shortcircuited to a signal line adjacent thereto in the intersection region; and

step (B) of forming a bypass circuit by use of the correction line such that a display signal to be supplied to the specified second type of signal line bypasses the intersection region.

12. The display fault correction method of claim 11, wherein the step (B) includes:

step (B1) of cutting the specified second type of signal line at a position upstream with respect to the intersection region and a position downstream with respect to the intersection region; and

step (B2) of connecting a part of the specified second type of signal line and one of two ends of the correction line to each other, and connecting another part of the specified second type of signal line and the other of the two ends of the correction line to each other.

13. The display fault correction method of claim 12, wherein the step (B1) and the step (B2) are performed by laser light radiation.