Controller of tracking position

Abstract

Abstract PURPOSE:To decrease the effect on a tracking position error detection due to a shift between a center shaft of a condenser lens and an incident optical axis, by performing identical movement to the condenser lens and a beam splitter in the radial direction of a disc. CONSTITUTION:The difference between two optical sensor outputs of a 2-split optical sensor 117 is calculated by a differential amplifier 118, a tracking position error signal is detected, and a tracking moving part 103 is driven in the arrow 111 by a tracking position control circuit 119 and a tracking actuator 110 so that a beam spot 107 is positined at the center of a tracking guide groove. Thus, the offset of the tracking position error signal due to the shift in the incident optical axis and the center axis of the condensor lens is decreased by performing identical movement to the condensor lens 105 and the polarized beam splitter 104 in the radial direction of the disc.

Inventors

• 👤 Hiroshi Inada
• 👤 稲田　博司

Bibliographic Details