Apparatus and method for automatically controlling focus-compensating in CD player

Abstract

A device for automatically adjusting focus compensation in an optical disc player, wherein the optical disc player includes: an optical pickup device, a focus error detector, and a focus servo unit, and the device for automatically adjusting focus compensation includes: a converter, Splitters, comparators, level detectors and control units. Also disclosed is a method for automatically adjusting a focus compensation operation in an optical disc player, comprising: outputting initial focus compensation data stored in a memory during a focus initial operation or a reset operation; separating the specific component signal from the radio frequency signal read by the pickup device; comparing the separated specific component signal with a reference signal to generate a phase difference value; and changing the initial focus compensation data to allow the phase difference to have a predetermined value A value within a range, an optimal focus compensation value is detected within a predetermined range, and the optimal focus compensation value is provided to control the focusing operation.

Description

technical field [0001] The present invention relates to an automatic focus control in an optical disc player, more particularly, it relates to an automatic focus control device and method for the optical disc player, which can make the optical disc player when the optical disc is in an abnormal situation (such as scratched or dusty) for reliable automatic control operation. Background technique [0002] Figure 1 is a functional block diagram of a generally conventional mini-disc player. Referring to FIG. 1, a pickup device 2 reads data from an optical disc 1 to provide an electrical signal. The RF signal generator 3 receives the electrical signal provided by the pick-up device 2 and generates an RF signal. The RF signal generated from the RF signal generator 3 is amplified to a predetermined level in the RF amplifier 4 and subjected to waveform shaping by an analog waveform shaping section 5 . Then, the signal output from the analog waveform shaping section 5 enters the d...

AI Technical Summary

Problems solved by technology

[0012] Furthermore, since some optical discs are only adjusted once on the assembly line, the conventional method has the disadvantage of not being able to obtain an accurate focus compensation value according to the type and state of the optical disc.

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