发明名称 |
Focus error detection device for an optical recording/playing back system |
摘要 |
A focus error detection device to be used in an optical system for recording and/or playing back information, including a light detector made up of four light receiving elements arranged symmetrically with respect to the center of the light detector, a multiplication means for generating a pair of multiplication signal by multiplying output signals of two light receiving elements which are arranged symmetrically with respect to the center of the light detector. The multiplication signals are applied to a subtraction means where the focus error signal is generated by the subtraction between the multiplication signals. Thereby the off-set of the focus error signal which has been caused by the deviation of the position of the center of the light beam from the center of the light detector is by far reduced.
|
申请公布号 |
US4663750(A) |
申请公布日期 |
1987.05.05 |
申请号 |
US19840662037 |
申请日期 |
1984.10.18 |
申请人 |
PIONEER ELECTRONIC CORPORATION |
发明人 |
HAMANAKA, KENJIRO;NOZU, SHINSAKU;SATO, KATSUHARU;TANAKA, HOZUMI |
分类号 |
G02B7/28;G11B7/09;(IPC1-7):G11B7/09 |
主分类号 |
G02B7/28 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|