摘要:
An optical pickup head apparatus comprises a yoke provided in an opposing relation to a magnet, a movable member having formed therethrough an aperture into which the yoke is inserted and around which a first coil is wound in an opposing relation to the magnet, an object lens supporting device having a pair of leaf springs for supporting the objective lens so that the objective lens can move in the direction parallel to the optical axis thereof and a plurality of second coils of substantially square shape for moving the objective lens in the direction parallel to the optical axis thereof and a tracking control device for rotating a mirror portion so that a beam spot focused on the optical disc by the objective lens follows a track on the optical disc, wherein the objective lens supporting device is secured to the movable member, the movable member is movably supported by the yoke and sides of the second coils which cross the optical axis of the objective lens and the first coil are located within a common magnetic gap.
摘要:
A recording and/or reproduction apparatus of an optical disc having recording tracks in which mirror areas are formed incorporates an optical head for recording or reproducing information signal onto or from the optical disc which has an optical detector for detecting a tracking error signal by a push-pull method; a fine actuator for precisely actuating the optical head finely; detecting means for detecting an output signal of the optical detector responding to reflected light from the mirror area; and driving means for driving the fine actuator in response to an output signal of the detecting means during the seeking operation.
摘要:
The method of the present invention comprises detecting a recording pattern, which is different for each tract, in each of track groups consisting of a predetermined number N or tracks recorded in advance on an optical disk(1), generating a tracking signal S.sub.ET whose signal level changes on the positive and negative sides of a target track T.sub.0 as the center, and moving the optical spot to the target track T.sub.0 on the basis of this tracking signal S.sub.ET. In this manner, it becomes possible to prevent uncontrollable movement of the optical spot and align the optical spot to a desired recording track within a short period of time.
摘要:
A focusing control method and apparatus employing a photodetector for generating a focusing error signal, a tracking error signal and an RF signal, and a closed loop focusing servo circuit responsive to the focusing error signal applied thereto for focusing a light spot in position on an optical disc. The focusing error signal is detected synchronously with the tracking error signal to produce a first periodic function signal. The focusing error signal is detected synchronously with the RF signal to produce a second periodic function signal. The tracking error signal is converted into a sin-wave signal having a predetermined amplitude. The RF signal is converted into a cos-wave signal having a predetermined amplitude. The first periodic function signal is multiplied by the cos-wave signal to produce a first component signal. The second periodic function signal is multiplied by the sin-wave signal to produce a second component signal. The first and second component signals are added to produce a composed disturbance signal. The composed disturbance signal is subtracted from the focusing error signal applied to the focusing servo circuit, thereby canceling a disturbance superimposed on the focusing error signal applied to the focusing servo circuit.