ELECTROSTATIC CAPACITIVE TOUCH SENSOR DEVICE

• US 20100328266A1
• Filed: 09/09/2010
• Published: 12/30/2010
• Est. Priority Date: 03/31/2008
• Status: Active Grant

• Current Assignee: Mitsubishi Jidosha Kogyo Kabushiki Kaisha, Visteon Japan, Ltd. (Visteon Corporation)
• Original Assignee: Mitsubishi Jidosha Kogyo Kabushiki Kaisha, Visteon Japan, Ltd. (Visteon Corporation)
• Inventors: Takizawa, Keitaro, Murayama, Yasunori, Tanaka, Sadahiko, YAMAUCHI, Kazuto, Yamanoue, Kouichi
• Granted Patent: US 8,654,097 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 2217/960755 Constructional details of capacitive touch and proximity switches

Abstract

An electrostatic capacitive touch sensor device includes sensing electrode provided at a plurality of positions, a high-frequency signal source that applies a high-frequency signal to the sensing electrode through a predetermined impedance element, a wiring portion that connects the sensing electrode and the impedance element, a shield portion provided to embrace the sensing electrodes and the connecting pattern, and a shield signal source that applies a shield signal to the shield portion and has the same phase and amplitude as the high-frequency signal source.

Claims

1. An electrostatic capacitive touch sensor device comprising:

a sensing electrode having an electrostatic capacitance value that changes depending on touch operation by an operator;

a high-frequency signal source that applies a high-frequency signal to the sensing electrode through a predetermined impedance element;

a wiring portion that connects the sensing electrode and the impedance element;

a shield portion provided close to the sensing electrode and the wiring portion so as to embrace the sensing electrode and the wiring portion; and

a shield signal source that applies a shield signal to the shield portion, wherein

the sensing electrode is provided at a plurality of positions,

the high-frequency signal source is provided singularly, and

the shield signal source is provided singularly, and has the same phase and amplitude as the high-frequency signal source.

2. The electrostatic capacitive touch sensor device according to claim 1, wherein the shield signal source includes an output buffer circuit portion, and is configured in a manner that an output impedance value of the shield signal source is smaller than an impedance value of the impedance element connected to the sensing electrode.

3. The electrostatic capacitive touch sensor device according to claim 1, wherein the high-frequency signal source is a rectangular wave signal generated by a C-MOS inverter element, the impedance is a resistor, and the buffer circuit portion is a C-MOS inverter element.

4. The electrostatic capacitive touch sensor device according to claim 2, wherein the high-frequency signal source is a rectangular wave signal generated by a C-MOS inverter element, the impedance is a resistor, and the buffer circuit portion is a C-MOS inverter element.