Sughrue Mion, PLLC
Ceramic heater and glow plug with reference zone and condensed zone of ceramics and conductive particles dispersed therein
A ceramic heater extending in an axial direction to have an elongate shape includes (a) a basal body; (b) a lead wire embedded in the basal body; and (c) a heating element embedded in the basal body. This heating element includes (1) a matrix ceramic phase; (2) conductive ceramic particles dispersed in the matrix ceramic phase; (3) a portion in which an end portion of the lead wire is embedded; and (4) a reference zone in terms of concentration of a particular element (e.g., rare-earth element). The heating element may include a condensed zone in terms of concentration of the particular element. The ceramic heater can be free from the condensed zone, or at least its formation is minimized to have a thickness of not greater than 5 &mgr;m. With this, the ceramic heater is improved in bending strength.
NGK Spark Plug Co., Ltd.
H H F
H05B H05B F23Q
additional inventional inventional
Shindo Masahiro
Watanabe Konishi