Patent ID: 6912190
Filing Date: 2005-06-28
Classification: G11B

Abstract:
1. An optical apparatus for reading address information from an optical disc which has tracks for recording information and track spaces, formed between the tracks, on which the address information to identify a position on the optical disc is recorded, said optical apparatus comprising: an optical head for irradiating the optical disc with light, said optical head including a first detector and a second detector located to be along the tracks, said first detector and said second detector for detecting the light reflected from the optical disc and outputting a first detection signal, and a second detection signal respectively; a balance adjusting circuit for address detection for receiving the first detection signal outputted by said first detector and the second detection signal outputted by said second detector, said balance adjusting circuit for address detection adjusting amplitudes of the first detection signal and the second detection signal and outputting an adjusted first detection signal and an adjusted second detection signal, respectively, at a position where the address information is recorded; an address detection differential amplifying circuit for outputting an address detection differential signal which is a difference between the adjusted first detection signal and the adjusted second detection signal adjusted by said balance adjusting circuit for address detection; and an address detecting circuit for detecting the address information based on the address detection differential signal outputted from said address detection differential amplifying circuit.