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:
Nov. 25, 2003
Filed:
May. 01, 2002
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A ceramic heater is configured such that a ceramic resistor includes a first resistor portion which is disposed at a front end portion of a heater body and which is formed of a first electrically conductive ceramic, and a pair of second resistor portions which are disposed on the rear side of the first resistor portion so as to extend along the direction of the axis O of the heater body The front end parts of the second resistor portions are joined to corresponding end parts of the first resistor portion as viewed along the direction of electricity supply. The second resistor portions are formed of a second electrically conductive ceramic having an electrical resistivity that is lower than that of the first electrically conductive ceramic. At least a portion of a joint interface between the first resistor portion and each of the second resistor portions deviates from a transverse plane P that perpendicularly intersects the axis O of the heater body The joint interface is formed of planes that perpendicularly intersect a reference plane K including the respective axes J of the second resistor portions