Nippondenso Co., Ltd.

Masataka Naitoh

Kazunori Suzuki

Yasuhumi Kojima

Kenji Tsukahara

Minoru Kuroda

Susumu Urano

A piezoelectric ceramic composition is disclosed wherein a sintered body having a bismuth layer structure represented by a molecular formula of PbBi.sub.4 Ti.sub.4 O.sub.15 contains 10 to 55 mol % of an oxide of Ca and Ti, namely CaTiO.sub.3, or 1 to 15 mol % of an oxide of Sr and Ti, namely, SrTiO.sub.3. The bismuth layer structure of PbBi.sub.4 Ti.sub.4 O.sub.15 has a positive dielectric-constant-temperature characteristic, and CaTiO.sub.3 or SrTiO.sub.3 is obtained by sintering as an added substance exhibiting a negative dielectric-constant-temperature characteristic. Since the added substance is added to the piezoelectric ceramic composition so that the temperature changes in both dielectric constants are mutually cancelled out, thereby maintaining the piezoelectric constants at a substantially fixed level.

Piezoelectric ceramic composition

A malfunction procedure indicating system which monitors continuously the condition of a plurality of inspection items associated with the operation of a vehicle, whereby when the existence of a malfunction in at least one of the plurality of inspection items is detected, a first procedure corresponding to the malfunction is indicated by both verbal representation and visual display during the operation of the vehicle and a second procedure following the first procedure is also indicated by both verbal representation and visual display.

Growing community of inventors

Kariya, Japan

Masataka Naitoh