Error correcting system and method for automatic power control circuit

Abstract

The invention is a kind of error correction system and method for the control loop. The loop at least includes a forestage amplifying circuit and a backstage amplifying circuit, the forestage circuit generates a forestage output signal. The system includes: comparator, error correcting module, judging loop. The comparator compares the output signal from the forestage circuit and the preset preference signal in order to produce a forestage compared signal; the error correcting module stores a preset and adjustable error correcting value, and adds into the forestage input signal; the judging circuit connects with comparator and error correction module with electricity, it can adjust the error correction value according to the comparing signal. The judging circuit can add the value into the input signal dynamically according to the error correction value, compensates and corrects the error of forestage output signal which caused by forestage amplifying circuit.

Description

technical field [0001] The invention relates to an error correction (offset calibration) system and method of an automatic power control loop, which is used for correcting errors generated by an automatic power control loop (automatic power control loop). Background technique [0002] The known optical head has an automatic power control loop to automatically control and adjust the laser power emitted by the laser diode of the optical head when writing and reading pit data on the optical disc. A general optical head includes a laser diode, a laser diode driver and a laser power sensor. The laser diode is used to provide a laser light source to read and write data on the optical disc, and the laser power sensor is used to detect the laser power of the light reflected from the optical disc to output a laser power sensor signal accordingly. [0003] When the optical head writes and reads, the laser power used is different, the power is high when writing, and the power is low w...

AI Technical Summary

Problems solved by technology

However, this method has a point that has not been considered, that is, when the laser power sensor signal sent by the laser power sensor has an error, the automatic power control loop will not be able to correct it in real time, and the amplification effect of the amplifier makes the original small The error value may be amplified to exceed the range that the adder can adjust, thus causing an error in the power control signal, and then causing an error in the laser power emitted by the laser diode, and the reading or writing of data on the optical disc will cause errors, affecting quite big

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