| 摘要 |
1,096,783. Piezoelectric elements. HITACHI SEISAKUSHO KABUSHIKI KAISHA. Feb. 2, 1965 [Feb. 5, 1964], No. 4515/65. Heading H1E. [Also in Division H4] A ceramic piezoelectric bimorph is produced by chemically reducing an intermediate or outer layer of a ceramic plate. For example, a lead titanate-zirconate sheet of 650Á thickness is heated for 15 mins. at 800‹ C. in hydrogen to reduce the whole sheet. The sheet is then heated for 2 hours at 650‹ C. in oxygen to produce surface oxidization to a depth of 150Á. The sheet is cut to size and the outer layers electrically polarized. The resistivity of the reduced layer may be about 10<SP>-1</SP> ohm/cm. cube. The method may be applied to tubes or square rods which are subsequently provided with two pairs of electrodes and used in stereophonic pick-ups. An intermediate reduced layer may also be produced by bonding together two sheets each having a reduced layer on one side only. |
