Optical disc drive and optical disc controller

An optical disc controller for use in an optical disc drive that includes an optical head, a tracking driver and a first tracking error signal generator,

• wherein the optical head includes:
• a light source that emits a light beam toward an optical disc having multiple data recording tracks thereon;
• a converging member that focuses the light beam to form a beam spot on one of the data recording tracks on the optical disc;
• an actuator that moves the converging member across the tracks;
• and a detector that detects the light beam that has been reflected from the optical disc, the tracking driver outputs a drive signal to the actuator, and the first tracking error signal generator generates a first tracking error signal, representing the location of the beam spot with respect to the track, based on an output signal of the detector,
• wherein the optical disc controller includes:
• a first lens position control section for outputting a first lens position control signal to the tracking driver, the first lens position control signal being obtained by extracting signal components, of which the frequencies are equal to or lower than a predetermined frequency, from the first tracking error signal;
• a second lens position control section for outputting a second lens position control signal to the tracking driver, the second lens position control signal being obtained by extracting DC components of the first tracking error signal at on-track points thereof;
• and
• a selector for selectively supplying the first tracking error signal to either the first lens position control section or the second lens position control section according to a moving velocity of the optical head that is performing a seek operation across the tracks on the optical disc.

A method for controlling an optical disc drive that includes an optical head, a tracking driver and a first tracking error signal generator,

• wherein the optical head includes:
• a light source that emits a light beam toward an optical disc having multiple data recording tracks thereon;
• a converging member that focuses the light beam to form a beam spot on one of the data recording tracks on the optical disc;
• an actuator that moves the converging member across the tracks;
• and a detector that detects the light beam that has been reflected from the optical disc, the tracking driver outputs a drive signal to the actuator, and the first tracking error signal generator generates a first tracking error signal, representing the location of the beam spot with respect to the track, based on an output signal of the detector,
• wherein the method comprises the steps of:
• selectively obtaining the first lens position control signal by extracting signal components, of which the frequencies are equal to or lower than a predetermined frequency, from the first tracking error signal, or the second lens position control signal by extracting DC components of the first tracking error signal at on-track points thereof, according to a moving velocity of the optical head that is performing a seek operation across the tracks on the optical disc:
• and
• outputting the selectively obtained first lens position control signal or second lens position control to the tracking driver.