| 摘要 |
PURPOSE:To decrease the displacement of a lens by detecting a signal to reflect the driving force of a conveying means, obtaining an operating force to move the lens with an operating force forecasting means and cancelling the driving force when a pick-up having an objective lens and a tracking driving device is driven in the radius direction of a disk. CONSTITUTION:The sum signal of two adjoining parts of a four-divided light- receiving element 65 on the lower surface of a tracking driving device 52 is outputted. A difference signal TE is a tracking error and inputted to a driving circuit 130 after the phase compensation. The circuit 130 is energized to a coil 9 of the driving device 52, an objective lens is moved and a light spot is made on the track of the disk. By the coil current, a driving signal TD is generated, a dislocation quantity from a neutral point is obtained by an integrator 160, given through a slider switch 180 to a circuit 200 together with a speed signal from a computer 240, a motor 21 is driven and the difference between a switch 180 and a motor speed sensor output is obtained by a difference device 190. A motor current is made into a driving force signal SF, a switch 120 is controlled, and the light spot of a driving device 50, namely, the objective lens to be mounted is kept on a track.
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