Electrostatic detection apparatus and method, and coordinate detection program

• US 20050275415A1
• Filed: 05/23/2005
• Published: 12/15/2005
• Est. Priority Date: 05/25/2004
• Status: Active Grant

• Current Assignee: Alps Alpine Co., Ltd.
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Sato, Tadamitsu, Ono, Shuzo
• Granted Patent: US 7,358,741 B2
• Time in Patent Office: Days
• US Class Current: 324/662
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A shielding member is provided as an electrostatic protection device in extension lines that extend from a sensing area to switching devices via extension areas correspondingly. As a result, even if a body to be detected such as a finger contacts the extension area, it is possible to reduce the amount of the change of an electrostatic capacitance with respect to the movement of the body to be detected. Therefore, it is possible to reduce influences exerted on data to be detected, and an electrostatic detection apparatus having improved coordinate detection accuracy can be provided.

Claims

1. An electrostatic detection apparatus comprising:

a sensing area for detecting that a body to be detected contacts or approaches the sensing area;

a plurality of sensor electrodes wired in the sensing area;

a routing-purpose extension line for connecting a section between individual sensor electrodes and an external circuit provided outside the sensing area; and

an extension area that is provided in the vicinity of the sensing area and in which the extension lines are arranged densely,

wherein electrostatic protection means for suppressing the change of an electrostatic capacitance formed between the body to be detected and the extension line when the body to be detected contacts or approaches the extension area is provided in the extension area.

2. The electrostatic detection apparatus according to claim 1, wherein the electrostatic protection means is formed by a shielding member that covers the extension area in which the extension lines are provided.

3. The electrostatic detection apparatus according to claim 2, wherein the shielding member is grounded.

4. The electrostatic detection apparatus according to claim 1, wherein the sensing area and the extension area are integrally covered with a cover sheet, and the electrostatic protection means is formed such that a plate thickness dimension of the cover sheet in the sensing area is formed thicker than a plate thickness dimension of the cover sheet in the extension area.

5. The electrostatic detection apparatus according to claim 4, wherein a step difference is formed between the cover sheet provided in the sensing area and the cover sheet provided in the extension area, and the step difference is formed in at least one of an obverse surface and a rear surface of the cover sheet.

6. The electrostatic detection apparatus according to claim 1, wherein the sensor electrodes are such that a plurality of X electrodes that extend in an X direction and that are arranged at a predetermined spacing in a Y direction, and a plurality of Y electrodes that extend in the Y direction and that are arranged at a predetermined spacing in the X direction are arranged so as to oppose each other in a matrix to intersect at right angles to each other.

7. An electrostatic detection apparatus for detecting a coordinate position by using a programmed computer, the electrostatic detection apparatus comprising:

a sensing area to which a body to be detected contacts or approaches;

a plurality of sensor electrodes in which an electrostatic capacitance is formed as a coordinate in a sensing area and that output a position of the body to be detected as a data signal indicating the change of the electrostatic capacitance;

an extension line for connecting a section between the individual sensor electrodes and an external circuit provided outside the sensing area;

an extension area that is provided in the vicinity of the sensing area and in which the extension lines are arranged densely;

detection means for obtaining a data signal in all the coordinates in the sensing area when an area in a predetermined range adjacent to the extension area within the sensing area is assumed to be a non-sensing area and the area other than the non-sensing area is assumed to be an operating area;

determination means for determining as to from which one of the non-sensing area and the operating area the detected data signal is output; and

coordinate specification means for specifying a coordinate position of the body to be detected by using the data signal when it is determined that the data signal is output from the operating area.

9. The electrostatic detection apparatus according to claim 7, further comprising area setting means for dividing the sensing area into a non-sensing area and an operating area.

11. The electrostatic detection apparatus according to claim 7, wherein the sensor electrodes are such that a plurality of X electrodes that extend in an X direction and that are arranged at a predetermined spacing in the Y direction, and a plurality of Y electrodes that extend in the Y direction and that are arranged at a predetermined spacing in a X direction are arranged so as to oppose each other in a matrix in such a manner as to intersect at right angles to each other.

8. An electrostatic detection apparatus for detecting a coordinate position by using a programmed computer, the electrostatic detection apparatus comprising:

a sensing area to which a body to be detected contacts or approaches;

a plurality of sensor electrodes in which an electrostatic capacitance is formed as a coordinate in a sensing area and that output a position of the body to be detected as a data signal indicating the change of the electrostatic capacitance;

detection means for obtaining a data signal in all coordinates in the sensing area when a boundary line formed from a predetermined shape is virtually formed in the sensing area, and one of an inside and an outside of the boundary line is assumed to be a non-sensing area and the other is assumed to be an operating area;

determination means for determining as to from which one of the non-sensing area and the operating area the data signal is output; and

coordinate specification means for specifying a coordinate position of the body to be detected by using the data signal when it is determined that the data signal is output from the operating area.

10. The electrostatic detection apparatus according to claim 8, wherein a plurality of patterns are provided as the predetermined shape, and one pattern can be selected from the plurality of patterns.

12. A method of detecting a coordinate position for use with an electrostatic detection apparatus by using a programmed computer, the method comprising the steps of:

forming an electrostatic capacitance as a coordinate in a sensing area and detecting a position of a body to be detected as a data signal indicating the change of the electrostatic capacitance when the body to be detected contacts or approaches the sensing area provided in the electrostatic detection apparatus;

dividing the sensing area into a non-sensing area and an operating area;

determining as to from which one of the non-sensing area and the operating area the detected data signal is output; and

specifying a coordinate position of the body to be detected by using the data signal when it is determined that the data signal is output from the operating area.

13. A program for detecting a coordinate for use with an electrostatic detection apparatus, the program allowing a computer to function as:

detection means for forming an electrostatic capacitance as a coordinate in a sensing area and detecting a the position of a body to be detected as a data signal indicating the change of the electrostatic capacitance when the body to be detected contacts or approaches the sensing area provided in the electrostatic detection apparatus;

determination means for determining as to from which one of a non-sensing area and an operating area the detected data signal is output when a predetermined area within the sensing area is set as a non-sensing area and the other area is set as an operating area; and

coordinate specification means for specifying a coordinate position of the body to be detected by using the data signal when it is determined that the data signal is output from the operating area.

14. The program for detecting a coordinate according to claim 13, further comprising area setting means for dividing the sensing area into a non-sensing area and an operating area.