Coordinate input device and display device

• US 8,159,471 B2
• Filed: 03/19/2008
• Issued: 04/17/2012
• Est. Priority Date: 04/20/2007
• Status: Active Grant

• Current Assignee: 138 East LCD Advancements Limited (Vector Capital Corporation)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Utsunomiya, Sumio, Koshihara, Takeshi, Ishii, Ryo
• Primary Examiner(s): Lao, Lun-Yi
• Assistant Examiner(s): Sadio, Insa
• Application Number:
  US12/051,175
• Publication Number:
  US 20080259044A1
• Time in Patent Office: 1,490 Days
• Field of Search: 345/156, 345/173, 345/87, 345/174, 345/104, 178/18.06, 178/18.01, 463/37
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

Provided is a coordinate input device including: a plurality of detection electrodes which are arranged in a planar shape in a detection area of a substrate; a plurality of routed wires connected to the plurality of detection electrodes; a coating film which coats the plurality of detection electrodes; a detection unit which detects a capacitance variation between the plurality of detection electrodes via the coating film; and a calculation unit which calculates a capacitance forming position from the detected result of the detection unit, wherein the plurality of detection electrodes are formed in the detection area in a first direction and are arranged in a second direction orthogonal to the first direction so as to configure a plurality of detection electrode pairs, each of which is composed of a pair of adjacent detection electrodes, a ratio of the width of one-side detection electrode of the pair of detection electrodes to the width of the other-side detection electrode of the pair of detection electrodes configuring each of the detection electrode pairs is changed according to the first direction, and the plurality of routed wires are connected to one ends of the first direction of the detection electrodes and are formed on the same layer as the plurality of detection electrodes.

Claims

1. A coordinate input device comprising:

a plurality of detection electrodes which are arranged in a planar shape in a detection area of a substrate;

a plurality of routed wires connected to the plurality of detection electrodes;

a coating film which coats the plurality of detection electrodes;

a detection unit which detects a capacitance variation between the plurality of detection electrodes via the coating film; and

a calculation unit which calculates a capacitance forming position from the detected result of the detection unit,

wherein the plurality of detection electrodes are formed in the detection area in a first direction and are arranged in a second direction orthogonal to the first direction so as to correspond to a plurality of detection electrode pairs, each of which is composed of a pair of adjacent detection electrodes,

a ratio of the width of one-side detection electrode of the pair of detection electrodes to the width of an other-side detection electrode of the pair of detection electrodes corresponding to each of the detection electrode pairs is changed according to the first direction,

each of the plurality of routed wires is connected to a respective one of the detection electrodes at an end of the electrode in the first direction and is formed on the same layer as the plurality of detection electrodes,

the plurality of detection electrodes corresponding to correction detection electrode pairs, each correction detection pair being composed of the one-side detection electrode corresponding to a detection electrode pair and the other-side detection electrode corresponding to another detection electrode pair adjacent to the one-side detection electrode, and

the calculation unit comprising;

a first coordinate calculation unit which calculates a first coordinate which is a detection position of the first direction, based on a sum of the capacitance variations of the one-side detection electrodes and a sum of the capacitance variations of the other-side detection electrodes; and

a second coordinate calculation unit which calculates a second coordinate which is a detection position of the second direction, from the capacitance variations of the detection electrode pairs, the capacitance variations of the correction detection electrode pairs, and the first coordinate.

2. The coordinate input device according to claim 1, wherein:

the appearances of the plurality of detection electrodes are equal,

the width of one-side detection electrode corresponding to each of the detection electrode pairs is decreased from one side to the other side of the first direction, and

the width of the other-side detection electrode is increased from one side to the other side of the first direction.

3. The coordinate input device according to claim 2, wherein a pair of sides of the plurality of detection electrodes in the first direction has a straight line shape.

4. The coordinate input device according to claim 3, wherein:

one of the pair of sides is parallel to the first direction and the other one thereof is inclined from the first and second directions, and

the other sides of the pair of detection electrodes corresponding to each of the detection electrode pairs face each other.

5. The coordinate input device according to claim 1, wherein the second coordinate calculation unit calculates the second coordinate which is corrected on the basis of the inclinations of central lines of a width direction of the correction detection electrode pairs to the central lines of a width direction of the detection electrode pairs.

6. A display device comprising:

the coordinate input device according to claim 1; and

another substrate which faces the substrate via a photoelectric layer.

7. The display device according to claim 6, wherein the plurality of detection electrodes are formed on a side of the substrate, which is separated from the photoelectric layer.

8. The display device according to claim 6, wherein the plurality of detection electrodes are formed on a side of the substrate, which is located at the side of the photoelectric layer.