Device equipped with planar heater

• US 8,263,913 B2
• Filed: 03/17/2008
• Issued: 09/11/2012
• Est. Priority Date: 03/29/2007
• Status: Active Grant

• Current Assignee: Godo Kaisha IP Bridge 1 (IP Bridge, Inc.)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Takeuchi, Kesatoshi
• Primary Examiner(s): PELHAM, JOSEPH MOORE
• Application Number:
  US12/077,183
• Publication Number:
  US 20080237219A1
• Time in Patent Office: 1,639 Days
• Field of Search: 219/522, 219/203, 219/213, 219/219, 219/505, 219/528, 219/535, 219/538, 219/547, 338/25
• US Class Current: 219/505
• CPC Class Codes: H05B 2203/013 Heaters using resistive films or coatings
• CPC Class Codes: H05B 3/84 Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields

Abstract

The planar heater includes an insulating substrate, an electric conductive film disposed on the substrate, a plurality of electrodes both attached to one side of the electric conductive film, and an insulating film covering the electric conductive film. The electric conductive film is preferably formed of material having a resistance temperature coefficient of 420 ppm/° C. or higher at normal temperature.

Claims

1. A device comprising a planar heater, the planar heater including:

an insulating substrate;

an electric conductive film disposed on the substrate, an entirety of the electric conductive film having a planar sheet-like form, the electric conductive film having a substantially rectangular shape with four sides;

a plurality of electrodes attached to one of the four sides of the electric conductive film while no electrodes are attached to the other three of the four sides; and

an insulating film covering the electric conductive film, wherein the electric conductive film is formed of material having a resistance temperature coefficient of 420 ppm/°

C. or higher at normal temperature, and

wherein, upon turning on the planar heater, a portion of the electric conductive film proximate the one side heats up due to electric current flow between the plurality of electrodes, the heating up causing an electrical resistance of the portion to increase which subsequently causes the electric current flow to progressively flow through and heat up other portions of the electric conductive film which are continuously more remote from the one side.

2. The device of claim 1, wherein the electric conductive film is formed of material having resistance of 4.8 μ

Ω

-cm or higher at normal temperature.

3. The device of claim 2, wherein the electric conductive film is formed of tungsten.

4. The device according to claim 1, wherein the planar heater is transparent.