Optical information reader

Abstract

Abstract PURPOSE: To realize a miniaturization with a simple mechanism and facilitate an easy mass production for an optical information reader, by controlling the focus position of the optical system by an actuator consisting of a unit of piezoelectric resonator pulse two coils attached to the resonator. CONSTITUTION: The resonator 18 attached with the optical system block 17 is supported by the springs 25W32 in a vertical/horizontal movable way. The piezoelectric ceramics 19 and the yoke 20 are attached to the resonator 18, and the magnets 21 and 22 plus coils 22 and 23 are installed inside the magnets and coils. Thus an actuator is constituted. The actuator receives the horizontal and vertical forces when the current flowing to the two coils is in the same way and in the opposite way to each other respectively. In such constitution, a variation of phase occurs to the reflected light in case the optical system is out of the pattern track. This variation is detected by the phase wave detector 34, and the fixed current is supplied to the coils 23 and 24 by the compensation signal generated from the compensation signal generator 35 to give the vertical or horizontal vibration to the resonator 18. As a result, the optical system can be made to follow onto the pattern in an accurate way. This following is also possible even when the focus has some shift. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Yasukazu Kawamura

Bibliographic Details