Sony Computer Entertainment Inc.

Hiroshi Ohtsu

Hironobu Amemiya

Masaki Sugiyama

Toshisada Takada

Koichiro Takahashi

In an optical disc apparatus, a minimum jitter value is established from each jitter value measured in correspondence to a successively changed servo constant, and multiplied by a prescribed ratio so as to set a jitter threshold value. Servo constants corresponding to at least two jitter values substantially equal to the jitter threshold value is established, and an optimum servo constant is set based on this minimum of two servo constants. By doing this, it is possible to quickly and accurately detect the optimum servo constant, and achieve good servo adjustment.

Optical disc apparatus and method for adjusting a servo of same

A position control method, which positions the relative position of an optical disk and an optical pickup to a position that provides the optimum value of the jitter value of the detection signal obtained by detecting the reflected light of an optical spot, has a jitter value acquisition procedure, which carries out multiple feed operations within the adjustment range of the relative position and obtains the jitter value at each feed position, an edge position setting procedure which sets as the edge positions relative positions that exceed a prescribed preset jitter threshold value, an optimum position computation procedure, which computes the optimum position that yields the optimum value for the jitter value, and an edge position setting procedure that sets the edge positions on the condition that there are at least two relative positions that yield a jitter value that exceeds the jitter threshold value.

Optical pickup position control method

A drive device has a feed mechanism that causes a control object to move in order to control the positioning of the control object, a motor that serves as the drive source of said feed mechanism, and a control means that controls this motor. The control means has an operation history memory unit that stores the operation history of whether the motor is doing an initial start or a restart, and a command selection unit that selects control commands and outputs them to said motor based on information stored in said operation history memory unit. Because intermittent operation that repeatedly drives and stops the motor occurs when there is a restart, the thermal shutdown associated with overheating of the driver IC is avoided, and any difference between the feed amount due to the control means and the actual feed amount can be prevented.

Drive device including a restart drive detection element

An optical pickup position control method that uses a stepping motor to control the position of the optical pickup, and that makes it possible to reduce the out-of-step noise generated from the motor and to accurately position the optical pickup, has a first procedure that gives the motor a control command to move the optical pickup in the direction toward the maximum feed position by a feed amount that is smaller than the maximum feed amount from base position to the motor's maximum feed position; a second procedure that gives the motor a control command to move the optical pickup in the direction toward base position by the maximum feed amount; and a third procedure that gives the motor a control command to move the optical pickup in the direction toward maximum feed position by the center position feed amount from base position to center position.

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Fukushima, Japan

Hiroshi Ohtsu