Liquid crystal display device with a built-in touch panel

• US 9,671,639 B2
• Filed: 08/19/2015
• Issued: 06/06/2017
• Est. Priority Date: 05/01/2012
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Abe, Hiroyuki, Maki, Masahiro, Suzuki, Takayuki
• Primary Examiner(s): Nguyen, Sang V
• Application Number:
  US14/829,996
• Publication Number:
  US 20150362778A1
• Time in Patent Office: 657 Days
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/134318 having a patterned common electrode
• 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 1/1345 Conductors connecting electrodes to cell terminals
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 2201/121 common or background
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

The presence or absence of touch is detected according to a difference of a capacitance caused by the presence or absence of a material that blocks the electric field formed between the detection electrode and the common electrode. The common electrode includes a plurality of divided electrode portions that is extended in a lateral direction and aligned with each other in a longitudinal direction. Each of the plurality of common lines is electrically connected to at least one of the divided electrode portions. The plurality of common lines is arranged in an area next to the common electrode in the lateral direction of the common electrode, arranged next to each other in a width direction orthogonal to a length thereof, is different in width from each other, and the width of the common lines is wider as the length is longer.

Claims

1. A liquid crystal display device with a built-in touch panel, comprising:

a first substrate and a second substrate;

a liquid crystal material held between the first substrate and the second substrate;

a plurality of pixel electrodes formed above the second substrate;

a common electrode formed above the second substrate;

a detection electrode formed above the first substrate; and

a plurality of common lines formed above the second substrate so as to be electrically connected to the common electrode,

wherein the liquid crystal material is driven by an electric field formed between the pixel electrodes and the common electrode which is applied a reference voltage,

wherein the presence or absence of touch is detected according to a difference of a capacitance between the detection electrode and the common electrode which is applied a detection voltage,

wherein the common electrode includes a plurality of divided electrodes extending in a lateral direction and aligned with each other in a longitudinal direction,

wherein the plurality of common lines is arranged in an area next to the common electrode in the lateral direction of the common electrode,

wherein the plurality of common lines has parallel arranged portions in the area next to the common electrode, each of the plurality of common lines having an end portion,

wherein an insulation layer is formed between the common lines and the divided electrodes, the insulation layer having a connecting opening formed above the end portion of each of the plurality of common lines,

wherein a conductive film, which is formed in the connecting opening, electrically connects between each of the plurality of common lines and some of the plurality of divided electrodes,

wherein each of the plurality of common lines has the end portion in a greater width in the lateral direction than a corresponding one of the parallel arranged portions in a width in the lateral direction and

wherein the end portion of a longer one of the plurality of common lines is wider in the lateral direction than the end portion of a shorter one of the plurality of common lines.

2. The liquid crystal display device with a built-in touch panel according to claim 1,

wherein each of the plurality of common lines has the end portion in the area next to the common electrode in the lateral direction, and extends from the end portion in the extension direction which is one of the vertical directions, and the end portions of the plurality of common lines are positionally displaced in the extension direction in the order from the longest common line to the shortest common line.

3. The liquid crystal display device with a built-in touch panel according to claim 2,

wherein the shortest common line is arranged at a side closest to the common electrode in the lateral direction,

wherein the longest common line is arranged at a side farthest from the common electrode in the lateral direction, and

wherein the plurality of common lines is more distant from the common electrode in the lateral direction as the common lines is longer.

4. The liquid crystal display device with a built-in touch panel according to claim 3,

wherein except for at least the shortest common line, the respective common lines each have a plurality of portions different in width along the extension direction,

wherein the number of the plurality of common lines is n,

wherein in a longitudinal side area that is adjacent to the end portion of an m (1≦

m)^th common line from the shortest common line on an upper side in the extension direction, and extends in a width direction, (m+1)^th to n^th common lines are arranged in parallel,

wherein in a lateral side area that is adjacent to the end portion of the m (1≦

m)^th common line from the shortest common line in the lateral direction, the (m+1)^th to n^th common lines are arranged in parallel,

wherein the longitudinal side area is wider in the lateral direction than the lateral side area, and

wherein in the (m+1)^th to n^th common lines, the width of a portion situated in the vertical side area is wider than the width of a portion situated in the lateral side area.

5. The liquid crystal display device with a built-in touch panel according to claim 4,

wherein a difference of the width in the lateral direction between the longitudinal side area and the lateral side area is equal to a width of the end portion of the m^th common line in the lateral direction.

6. The liquid crystal display device with a built-in touch panel according to claim 5,

wherein a difference between a total of the widths of the portions of the (m+1)^th to n^th common lines provided in the longitudinal side area, and a total of the widths of the portions of the (m+1)^th to n^th common lines provided in the lateral side area is equal to the width of the end portion of the m^th common line in the lateral direction.

7. The liquid crystal display device with a built-in touch panel according to claim 6,

wherein the number of the conductive film is larger as the length of the one common line electrically connected thereto is larger.

8. The liquid crystal display device with a built-in touch panel according to claim 1,

wherein the second substrate further includes a circuit, and

wherein the plurality of common lines is formed to overlap with the circuit.

9. The liquid crystal display device with a built-in touch panel according to claim 1,

wherein the pixel electrodes and the common electrode are formed on the second substrate, and

wherein the electric field formed between the pixel electrodes and the common electrode is a lateral electric field.

10. A liquid crystal display device with a built-in touch panel, comprising:

a liquid crystal material;

a first substrate and a second substrate between which the liquid crystal material is held;

pixel electrodes formed between the first substrate and the second substrate;

a common electrode formed between the first substrate and the second substrate;

a detection electrode formed on the first substrate; and

a plurality of common lines formed on the second substrate so as to be electrically connected to the common electrode,

wherein the liquid crystal material is driven by an electric field formed between the pixel electrodes and the common electrode which is applied a reference voltage,

wherein the presence or absence of touch is detected according to a difference of a capacitance between the detection electrode and the common electrode which is applied a detection voltage,

wherein the common electrode includes a plurality of divided electrodes extending in a lateral direction and aligned with each other in a longitudinal direction,

wherein the plurality of common lines are formed in a side area next to the common electrode in the lateral direction and next to each other in a width direction orthogonal to an extension direction thereof,

wherein the plurality of common lines has parallel arranged portions in the side area, each of the plurality of common lines having an end portion,

wherein the parallel arranged portions are arranged in parallel to each other, and different in width from each other,

wherein a longer one of the plurality of common lines in total length has a corresponding one of the parallel arranged portions wider in width than a shorter one of the plurality of common lines,

wherein each of the plurality of common lines has an end portion in parallel to another of the plurality of common lines at a corresponding one of the parallel arranged portions and next to the plurality of divided electrodes in the lateral direction, each of the plurality of common lines having the end portion nearer than the corresponding one of the parallel arranged portions,

wherein an insulation layer is formed between the common lines and the divided electrodes, the insulation layer having a connecting opening formed above the end portion of each of the plurality of common lines,

wherein a conductive film, which is formed in the connecting opening, electrically connects between each of the plurality of common lines and some of the plurality of divided electrodes,

wherein the end portion extends along an arrangement of the plurality of divided electrodes in the side area,

wherein each of the plurality of common lines has the end portion in a greater width in the lateral direction than a corresponding one of the parallel arranged portions in a width in the lateral direction, and

wherein the end portion of a longer one of the plurality of common lines is wider in the lateral direction than the end portion of a shorter one of the plurality of common lines.

11. The liquid crystal display device with a built-in touch panel according to claim 10,

wherein end portions in the side area of the plurality of common lines are arranged in the longitudinal direction in the order from the longest common line to the shortest common line.

12. The liquid crystal display device with a built-in touch panel according to claim 10

wherein the shortest common line in the side area is arranged at a side closest to the common electrode in the lateral direction, and

wherein the longest common line in the side area is arranged at a side farthest from the common electrode in the lateral direction.

13. The liquid crystal display device with a built-in touch panel according to claim 10,

wherein except for at least the shortest common line, the respective common lines each have the plurality of parallel arranged portions different in width along the extension direction,

wherein the number of the plurality of common lines is n,

wherein the plurality of common lines includes mth (1≦

m<

n) and (m+1)th common line,

wherein the mth common line has mth end portion,

wherein the (m+1)th common line has (m+1)th end portion,

wherein (m+1)th to nth parallel arranged portions are arranged in a lateral side area which is situated in the lateral direction next to the mth end portion,

wherein mth end portion and (m+2)th to nth parallel arrange portions are arranged in a longitudinal side area which is situated in the longitudinal direction next to the mth end portion,

wherein a total width in the lateral direction of the longitudinal side area is wider than a total width in the lateral direction of the lateral side area.

14. The liquid crystal display device with a built-in touch panel according to claim 10

wherein a difference of the width in the lateral direction between the longitudinal side area and the lateral side area is equal to a width of the end portion of the m^th common line in the lateral direction.

15. The liquid crystal display device with a built-in touch panel according to claim 13,

wherein the width in the lateral direction of the (m+1)th end portion is wider than that of the (m+1)th parallel arranged portion in the lateral side area.