The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 12, 2008
Filed:
Feb. 27, 2003
Applicants:
Takao Kojima, Aichi, JP;
Keisuke Makino, Aichi, JP;
Shinya Awano, Aichi, JP;
Inventors:
Assignee:
NGK Spark Plug Co., Ltd., Aichi, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B 3/44 (2006.01);
U.S. Cl.
CPC ...
Abstract
A prismatic ceramic heater for heating a gas sensor element includes a heating resistor embedded in ceramic, and has a substantially rectangular cross section. At least part of a longitudinally extending edge portion of the prismatic ceramic heater is located in the vicinity of the heating resistor. This part of the longitudinally extending edge portion is coated with a porous protective layer. The protective layer has a thickness not less than 20 μm and a curved surface of a curvature radius not less than 10 μm. The protective layer prevents cracking induced by contact with water.