| 摘要 |
PURPOSE:To attain a simple structure and to attain highly efficient drive by holding an objective lens to the free end of a connecting body where tow laminated type piezoelectric ceramics are connected in series so as to displace the two piezoelectric substances in the same direction. CONSTITUTION:The 1st and 2nd laminated piezoelectric ceramics 221, 222 are connected in sereis via a rigid member 224 and a reflected type connecting member 227 to form a connecting body, and an objective lens 209 is fitted to the holding member 226 being its free end. Through a constitution above, in case of focus drive, a voltage is impressed to expand both the ceramics 221, 222 or contract the both by using a drive signal 220 and the sum of the both displaces vertically the lens 209. Thus, the constitution is simplified, the electric conversion efficiency is 50% due to a direct drive and the drive with high efficiency 3-4 times that of the electromagnetic type is attained.
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