Electrostatic detection apparatus and method, and coordinate detection program

• US 7,492,169 B2
• Filed: 01/22/2007
• Issued: 02/17/2009
• 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: Ono, Shuzo, Sato, Tadamitsu
• Primary Examiner(s): Nguyen; Vincent Q
• Application Number:
  US11/625,645
• Publication Number:
  US 20070115002A1
• Time in Patent Office: 757 Days
• Field of Search: 324/457, 324/662, 324/686
• US Class Current: 324/686
• 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 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.

2. The electrostatic detection apparatus according to claim 1, further comprising area setting means for dividing the sensing area into a non-sensing area and an operating area.

3. 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 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.

4. 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.

5. The electrostatic detection apparatus according to claim 4, wherein a plurality of patterns are provided as the predetermined shape, and one pattern can be selected from the plurality of patterns.

6. 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.

7. 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 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.

8. The program for detecting a coordinate according to claim 7, further comprising area setting means for dividing the sensing area into a non-sensing area and an operating area.