Optical disk apparatus using transition control between positioner seek control and lens seek control

An optical disk apparatus comprising:

• an optical disk rotated at a predetermined velocity, said optical disk having tracks;
• an optical head having an object lens incident to a light beam from a light source for said optical disk;
• a positioner to move said optical head in a direction crossing the tracks of said optical disk;
• a tracking actuator, mounted on said optical head, to actuate the object lens to move the light beam in the direction crossing the tracks;
• positioner seek control means for controlling said positioner, by producing a target light beam velocity based on a current track position and a target track position, detecting a light beam velocity at a first time interval, and moving said positioner to cause the light beam velocity to be coincident with the target light beam velocity in accordance with an error value between the target light beam velocity and the detected light beam velocity, said positioner seek control means controlling acceleration and deceleration of the light beam;
• transition control means for controlling said positioner by detecting a light beam velocity at a second time interval which is faster than the light target beam velocity at the first time interval, where in controlling deceleration of the light beam by said positioner seek control means a remaining track number of the tracks remaining to the target track becomes a predetermined number;
• and
• lens seek control means for controlling said tracking actuator to move the light beam to the target track position by detecting light beam velocity, and controlling said tracking actuator based upon an error between the target light beam velocity and the detected light beam velocity, where in controlling deceleration of the light beam, the light beam velocity detected by said transition control means is lowered below a second predetermined light beam velocity at which control of said positioner by said lens seek control means is possible.

An optical disk apparatus comprising:

• an optical disk rotated at a predetermined velocity, said optical disk having tracks;
• an optical head having an object lens incident to a light beam from a light source for said optical disk;
• a positioner to move said optical head in a direction crossing the tracks of said optical disk;
• a tracking actuator, mounted on said optical head, to actuate the object lens to move the light beam in the direction crossing the tracks;
• positioner seek control means for controlling said positioner by producing a target light beam velocity based on a current track position and a target track position, detecting a light beam velocity at a first time interval, and moving said positioner to cause the light beam velocity to be coincident with the target light beam velocity in accordance with an error value between the target light beam velocity and the detected light beam velocity;
• transition control means for controlling said positioner for detecting a light beam velocity at a second time interval which is faster than for the first time interval, where in controlling deceleration of the light beam, the light beam velocity detected by said positioner seek control means is lowered below a first predetermined velocity and a remaining track number of tracks remaining to the target track becomes a predetermined number;
• and
• lens seek control means for controlling said tracking actuator to move the light beam to the target track position by detecting light beam velocity, and controlling said tracking actuator based on an error between the target light beam velocity and the detected light beam velocity, where in controlling deceleration of the light beam, the light beam velocity detected by said transition control means is lowered below a second predetermined light beam velocity at which control of said positioner by said lens seek control means is possible.

An optical disk apparatus for use with an optical disk having tracks, comprising:

• an optical head having an object lens transmitting and receiving a light beam to and from, respectively, the optical disk;
• a positioner coupled to the optical head, for moving the optical head in a direction crossing the tracks of the optical disk;
• a velocity sensor electromechanically coupled to the positioner;
• a tracking actuator coupled to the optical head, for actuating the object lens to move the light beam in the direction crossing the tracks,
• the positioner being moved based on a first target light beam velocity determined based on a current track position and a target track position during a positioner seek operation,
• the tracking actuator being controlled to move the object lens based on an error between a second target light beam velocity and a detected light beam velocity during a lens seek operation, and
• the positioner being controlled using a light beam velocity detected by the velocity sensor during a transition operation occurring between the positioner seek operation and the lens seek operation.