发明名称 |
Optical disk tracking method and device for producing a tracking error signal and a track crossing signal |
摘要 |
An optical disk device includes an optical system having a beam converting unit and an objective lens. The beam converting unit converts a beam of laser light emitted by a laser light source into a main beam and at least one sub-beam. The objective lens places a main spot on the disk by the main beam and at least one sub-spot on the disk by the sub-beam, such that, when the main spot is on a center line of one of lands and grooves of an optical disk, the sub-spot is between the center line of one of the lands and the grooves and a center line of an adjacent one of the lands and the grooves. A first unit produces a first push-pull signal from a reflection beam from the main spot on the disk. A second unit produces a second push-pull signal from a reflection beam from the sub-spot on the disk. A tracking error signal generating unit produces a tracking error signal based upon the first push-pull signal. A track crossing signal generating unit produces a track crossing signal based upon the second push-pull signal.
|
申请公布号 |
US5828634(A) |
申请公布日期 |
1998.10.27 |
申请号 |
US19970808986 |
申请日期 |
1997.02.20 |
申请人 |
RICOH COMPANY, LTD. |
发明人 |
OHNO, TAKEHIDE;MAEGAWA, HIROSHI |
分类号 |
G11B7/09;(IPC1-7):G11B7/00 |
主分类号 |
G11B7/09 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|