PIEZOELECTRIC LINEAR MOTORS FOR DRIVING HEAD ELEMENT OF CD-ROM

This paper deals with piezoelectric linear motors for driving an optical pickup element of CD-ROM. These linear motors have such merits in that they can be made thin because of their simple construction, and they are suitable for precise positioning owing to their operation principle of using ultrasonic vibrations of essentially very small displacements. We can expect that the input power of these motors will be economized due to their self-position-retention function. Therefore, in order to achieve such linear motors, we have already reported some piezoelectric linear motors of the self-moving type. On the other hand, in this paper, the authors investigated some stationary piezoelectric linear motors which could easily be constructed in a flat shape. Compared with the self-moving piezoelectric linear motors reported previously, the stationary piezoelectric linear motors have the merit that they easily generate a uniform pressing force. In this paper, the structure, operation principles, and characteristics of such stationary linear motors are described, and moreover, a method to lower the driving voltage of these linear motors is reported.