Coordinate input device

• US 20020186210A1
• Filed: 06/04/2002
• Published: 12/12/2002
• Est. Priority Date: 06/07/2001
• Status: Active Grant

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Itoh, Akihisa
• Granted Patent: US 7,218,314 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• 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
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures

Abstract

A coordinate input device includes a coordinate input element. The coordinate input element includes a transparent coordinate detector and a controller having a control circuit which drives and controls the coordinate detector and which corrects electrostatic capacitance noise disturbing the coordinate detector. The coordinate input device also includes a liquid crystal display device provided on the back side of the coordinate input element, a casing for holding the coordinate input element and the liquid crystal display device, and an L-shaped and a reverse L-shaped push button switches provided on the upper surface of the casing.

Claims

1. A coordinate input device comprising:

a coordinate detector including;

a first insulating layer which has transparency and which is formed at the top;

a first electrode layer having a plurality of linear transparent electrodes formed in parallel on the lower surface of the first insulating layer;

a second insulating layer which has transparency and which is formed on the lower surface of the first electrode layer;

a second electrode layer having a plurality of linear transparent electrodes which are aligned in parallel and which extend in the direction orthogonal to the transparent electrodes of the first electrode layer, the second electrode layer being formed on the lower surface of the second insulating layer; and

a third insulating layer which has transparency and which is formed on the lower surface of the second electrode layer, and

a controller which is electrically connected to the two electrode layers of the coordinate detector so as to drive and control the electrode layers and which has correction means for removing electrostatic capacitance noise that disturbs the coordinate detector.

6. The coordinate input device according to claim 1, wherein the controller comprises reference signal storing means for storing a reference signal, which is a detection signal obtained by scanning the electrodes of the first electrode layer and the second electrode layer while no operation is performed;

and correction value calculating means for subtracting the reference signal from a detection signal while an operation is performed, thereby correcting the detection signal during the operation.

7. The coordinate input device according to claim 1, wherein each of the first insulating layer, the second insulating layer, and the third insulating layer comprises a flexible resin substrate.

8. The coordinate input device according to claim 1, wherein the light transmittance of the coordinate detector is 90% or more.

2. A coordinate input device comprising:

a coordinate detector including;

a first insulating layer which has transparency and which is formed at the top;

a first electrode layer having a plurality of linear transparent electrodes formed in parallel on the lower surface of the first insulating layer;

a second insulating layer which has transparency and which is formed on the lower surface of the first electrode layer;

a second electrode layer having a plurality of linear transparent electrodes which are aligned in parallel and which extend in the direction orthogonal to the transparent electrodes of the first electrode layer, the second electrode layer being formed on the lower surface of the second insulating layer; and

a third insulating layer which has transparency and which is formed on the lower surface of the second electrode layer, and

a display device placed on the back side of the coordinate detector,

wherein a scanning frequency for scanning the electrodes of the coordinate input device is different from a driving frequency of the display device.

3. The coordinate input device according to claim 2, further comprising a controller which is electrically connected to the two electrode layers of the coordinate detector so as to drive and control the electrode layers and which has correction means for removing electrostatic capacitance noise that disturbs the coordinate detector.

4. The coordinate input device according to claim 2, wherein the display device is a liquid crystal display device or an EL display device in which electroluminescent elements are aligned.

5. The coordinate input device according to claim 2, wherein a ground layer comprising a conductor is provided on the back side of the display device.

9. The coordinate input device according to claim 3, wherein the coordinate detector and the controller of the coordinate input device are connected by a flexible wiring board, and the flexible wiring board is placed on a side of the display device so that the controller is placed on the back side of the display device.

10. The coordinate input device according to claim 2, wherein the coordinate detector and the display device are held on a casing and one or a plurality of push button switches are provided on the upper surface of the casing.