Touch panel

• US 9,882,560 B2
• Filed: 04/19/2013
• Issued: 01/30/2018
• Est. Priority Date: 04/23/2012
• Status: Expired due to Fees

• Current Assignee: Fujitsu Component Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Component Limited (Fujitsu Limited)
• Inventors: Ueno, Yutaka
• Primary Examiner(s): BARNIE, REXFORD N
• Assistant Examiner(s): Inge, Joseph
• Application Number:
  US13/866,149
• Publication Number:
  US 20130278080A1
• Time in Patent Office: 1,747 Days
• Field of Search: 307119
• 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, each of the four electrodes being electrically connected to a corresponding one of four current detecting units; and

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

wherein when an insulating object is placed in direct contact with the first conductive film, the four current detecting units detect electric currents flowing at the fours electrodes, respectively, the electric currents flowing as a result of electrical charge of the insulating object placed in direct contact with the first conductive film, and a position at which the insulating object is in direct contact with the first conductive film is determined based on respective amounts of the detected electric currents.

2. The touch panel as claimed in claimed 1, wherein the insulating object is an insulating touch pen.