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:
Apr. 13, 2004
Filed:
May. 01, 2002
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A ceramic heater includes a rodlike heater body configured such that a ceramic resistor is embedded in a ceramic substrate . The ceramic resistor includes a front end part and two large-diameter rodlike portions Ld. The large-diameter rodlike portions Ld form passages for supplying electricity to the front end part , extend rearward along a direction of an axis O of the heater body , and have an electricity-supply sectional area greater than that of the front end part . The large-diameter rodlike portions Ld each have a connection end part connected to the front end part . The connection end part is formed of a first electrically conductive ceramic and constitutes a first resistor portion . The remaining portion of each of the large-diameter rodlike portions Ld is formed of a second electrically conductive ceramic having an electrical resistivity lower than that of the first electrically conductive ceramic and constitutes a second resistor portion . A joint interface between the first resistor portion and the second resistor portion is located within the corresponding large-diameter rodlike portions Ld.