| Patent Number |
Title Of Patent |
Date Issued |
| 6353583 |
Signal operational circuit for a multi-beam pick-up device |
March 5, 2002 |
| The present invention provides a large scale integrated circuit (LSI) for calculating servo signals (e.g., a focusing signal, a tracking signal, etc.) from the output signals received from a plurality of photo detectors, as used within an optical disk apparatus. The invention provide |
| 6128259 |
Optical pickup apparatus for accurate detection of a tracking error signal |
October 3, 2000 |
| In order to accurately detect a tracking error signal, the position of a sub-beam Bs1 with a lower shading rate is located at a position ahead of the position of a main beam Bm in the recording direction of an optical disk, and the position of a sub-beam Bs2 with a higher shading rate is |
| 5991251 |
Method and apparatus for changing laser beam power of an optical storage device for various type |
November 23, 1999 |
| A layer beam controller for an optical storage apparatus includes a laser beam generator, a laser beam power varier for varying the laser beam power to first, second, and third power levels, a memory for storing predetermined reference values including first reference values correspo |
| 5341355 |
Multibeam optical pickup and servo method thereof |
August 23, 1994 |
| A servo method in a multibeam optical pickup in which, at the time of a recording mode, a record information is confirmed and reproduced by a beam for reproduction while the record information is written by a beam for record, and the record information is reproduced by the beam for r |
| 5105410 |
Multi-beam optical pick-up |
April 14, 1992 |
| A multi-beam optical pick-up for use in an optical disc system includes a light source for emitting two light beams which are focused onto an optical disc to form two light spots thereon. The pick-up also includes an optical system to receive light reflected from the optical system and t |
| 4853934 |
Semiconductor laser control apparatus |
August 1, 1989 |
| A semiconductor laser control apparatus comprises a light receiving part for receiving a laser beam emitted from a semiconductor laser, a comparator for comparing an output signal of the light receiving part and a reference signal having a level corresponding to a desired target value |
