Electric mechanical conversion element

Abstract

Abstract PURPOSE: To increase the accuracy of position adjustment such as magnetic head, by reducing the residual displacement, through the use of a porcelain plate in non-ferro-dielectric phase within the operating temperature. CONSTITUTION: The position control of the magnetic head having narrow track width such as VTR etc. requires high accuracy and control is made by using electric mechanical conversion element, as the element, the electrodes 12a and 12b are coated on the both major planes, and two non-ferrodielectric porcelain plates in non- ferro dielectric phase within the operating temperature are constituted for the element of bimorph construction by clipping the metal substrate 13, and one of the power supply 14 is connected to the substrate 13 and another is to the electrode 12a of the pocelain plate 11 via the switch 15. With this construction, one example of the displacement amount due to electrorestriction effect when the polarity of applied voltage is inverted is within ± 1 μm for the residual displacement to the amplitude of ± 45 μm and the residual displacement when the piezoelectric effect of the ferrodielectric porcelain is utilized as element is remarkably reduced and the positioning of head can be made with good accuracy. COPYRIGHT: (C)1979,JPO&Japio

Inventors

• 👤 Tomosaburo Kitamura
• 👤 Yoichi Kodera

Bibliographic Details