TOUCH PANEL

• US 20130278080A1
• Filed: 04/19/2013
• Published: 10/24/2013
• Est. Priority Date: 04/23/2012
• Status: Active Grant

• Current Assignee: Fujitsu Component Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Component Limited (Fujitsu Limited)
• Inventors: Ueno, Yutaka
• Granted Patent: US 9,882,560 B2
• Time in Patent Office: Days
• US Class Current: 307/119
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0444 using a single conductive element covering the whole sensing surface, e.g. by sensing the electrical current flowing at the corners
• CPC Class Codes: H03K 17/96 Touch switches specially adapted for electronic time-pieces with no moving parts G04G21/08

Abstract

A touch panel includes a transparent dielectric substrate having a generally rectangular shape, a first conductive film formed on a first surface of the dielectric substrate, a second conductive film formed on a second surface of the dielectric substrate, four electrodes formed at four respective corners of the first conductive film, four current detecting units coupled to the four electrodes, respectively, and an alternating-current power supply configured to apply alternating-current voltage between the first conductive film and the second conductive film, wherein the alternating-current power supply is electrically coupled to the first conductive film through the four current detecting units and the four electrodes.

Claims

1. A touch panel, comprising:

a transparent dielectric substrate having a generally rectangular shape;

a first conductive film formed on a first surface of the dielectric substrate;

a second conductive film formed on a second surface of the dielectric substrate;

four electrodes formed at four respective corners of the first conductive film;

four current detecting units coupled to the four electrodes, respectively; and

an alternating-current power supply configured to apply alternating-current voltage between the first conductive film and the second conductive film,

wherein the alternating-current power supply is electrically coupled to the first conductive film through the four current detecting units and the four electrodes.

2. The touch panel as claimed in claim 1, wherein a position of a point at which an object is in contact with the first conductive film is detected in response to amounts of electric currents detected by the four current detecting units.

3. The touch panel as claimed in claim 2, wherein the position of the point is detectable for the object made of an insulation material.

4. The touch panel as claimed in claim 1, further comprising a flexible substrate that is electrically coupled to at least one of the first conductive film and the second conductive film.

5. The touch panel as claimed in claim 1, further comprising a case unit made of a conductive material configured to cover the second surface of the dielectric substrate.