Patent ID: 7870463

Claim:
An optical disc recording and playback apparatus comprising: a laser light source irradiating an optical disc with laser light; and an optical pickup converting reflected light from the optical disc into a plurality of electrical signals via a split photo detector, the optical disc recording and playback apparatus recording information on the optical disc, and reading information stored in the optical disc and playing back the read information, wherein the optical disc recording and playback apparatus comprises: a first signal generating portion producing a first error signal from the plurality of electrical signals corresponding to a main beam of the reflected light, multiplying the first error signal by a previously set first gain, and outputting a resultant signal; a second signal generating portion producing a second error signal from the plurality of electrical signals corresponding to a sub beam of the reflected light, multiplying the second error signal by a previously set second gain, and outputting a resultant signal; a third signal generating portion producing a tracking error signal by obtaining a difference between the first error signal and the second error signal by subtracting the second error signal from the first error signal; a gain storing portion previously storing the first gain and the second gain; a gain setting portion determining appropriate values of the first gain and the second gain when playback of the optical disc is performed, recording the first gain and the second gain thus determined in the gain storing portion, and setting the first gain and the second gain in the first signal generating portion and the second signal generating portion, respectively; and a correction performing portion reading, when recording on the optical disc is performed, the first gain and the second gain stored in the gain storing portion, correcting at least one of the first gain and the second gain, and setting the first gain and the second gain in the first signal generating portion and the second signal generating portion, respectively.