Method for finding disconnection of conductive wires formed on plate glass and apparatus therefor

• US 20040124358A1
• Filed: 07/22/2003
• Published: 07/01/2004
• Est. Priority Date: 01/24/2002
• Status: Active Grant

• Current Assignee: Central Glass Company Limited
• Original Assignee: Central Glass Company Limited
• Inventors: Okamura, Shinichi, Ookita, Masahiko
• Granted Patent: US 7,332,718 B2
• Time in Patent Office: Days
• US Class Current: 250/341.1
• CPC Class Codes: G01J 5/0096 for measuring wires, electrical contacts or electronic systems
• CPC Class Codes: G01N 25/72 Investigating presence of flaws
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: G01R 31/54 Testing for continuity
• CPC Class Codes: G01R 31/58 Testing of lines, cables or conductors testing of electric windings G01R31/72
• CPC Class Codes: H05B 1/0236 for vehicles
• CPC Class Codes: H05B 2203/035 Electrical circuits used in resistive heating apparatus
• 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 invention relates to a method for finding disconnection of a conductive wire formed on a plate glass. This method includes the steps of (a) applying a voltage to the conductive wire; and (b) imaging thermal radiation from a surface of the conductive wire by an infrared image sensor, while the step (a) is conducted, thereby producing a temperature distribution image. An apparatus for conducting the method includes (a) a power source for applying a voltage to the conductive wire; and (b) an infrared image sensor for imaging thermal radiation from a surface of the conductive wire, thereby producing a temperature distribution image.

Claims

1. A method for finding disconnection of a conductive wire formed on a plate glass, the method comprising the steps of:

(a) applying a voltage to the conductive wire; and

(b) imaging thermal radiation from a surface of the conductive wire by an infrared image sensor, while the step (a) is conducted, thereby producing a temperature distribution image.

2. A method according to claim 1, wherein the temperature distribution image is subjected to a binarization by an image processor.

3. A method according to claim 1, wherein the temperature distribution image is compared with a data representing a pattern of the conductive wire.

4. A method according to claim 3, wherein the data is a first image data obtained by drafting the pattern of the conductive wire.

5. A method according to claim 3, wherein the data is a second image data obtained, prior to the step (a), by imaging thermal radiation from the surface of the conductive wire by the infrared image sensor.

6. A method according to claim 3, wherein the comparison is conducted by superimposing the temperature distribution image on the data.

7. A method according to claim 3, wherein the comparison is conducted by an image data subtraction between the temperature distribution image and the data.

8. An apparatus for finding disconnection of a conductive wire formed on a plate glass, the apparatus comprising:

a power source for applying a voltage to the conductive wire; and

an infrared image sensor for imaging thermal radiation from a surface of the conductive wire, thereby producing a temperature distribution image.

9. An apparatus according to claim 8, wherein the infrared image sensor is an infrared camera.