| 摘要 |
PURPOSE:To warp second and third electrodes in the opposite directions for causing the front end to twist and to facilitate the angular control of a head, by providing piezoelectric elements with second and their electrodes having opposite polarities. CONSTITUTION:Piezoelectric elements 1a and 1b are bonded each other to form a bimorph 1. First to third electrodes 2-4 are formed on both exterior surfaces of the piezoelectric elements 1a and 1b. The reference numeral 5 indicates an intermediate electrode formed over the joint area between the piezoelectric elements 1a and 1b. The electrodes 2-4 are connected between the two exterior surfaces. The reference numeral 1c indicates a notch provided between the electrodes 3 and 4. The arrows indicate the polarizing directions of the piezoelectric elements. In operation, the piezoelectric element expands when a voltage is applied in the same direction as the polarizing direction and contracts when a voltage is applied in the reverse direction. When a voltage V1 as shown in the drawing is applied, the first electrode is warped from a support base 6 toward the front end. When a voltage V2 is applied, the second electrode is warped in the same direction as the first electrode while the third electrode is warped reversely, whereby the support base moves in a twisted manner. Accordingly, the directions of deflection and of warpage can be freely selected through the polarities of the voltages V1 and V2 and the magnitude thereof. |
