Title:
【発明の名称】情報媒体のトラック走査用光ビームのフォーカシング制御信号生成装置及び方法
Document Type and Number:
Japanese Patent JPH06103537
Kind Code:
B2
Abstract:
The process makes it possible to generate on the basis of discrete preetching elements or flags, the radial tracking error and/or focusing error signals. The flags comprise portions displaced with respect to the mean axis of the tracks to be followed. According to a first variant, each track comprises portions displaced on either side of the axis. According to a second variant the flags comprise portions alternately displaced to one and then the other side thereof. In response to the passages of these portions, windows are generated and the pulses supplied by the photodetectors of the interaction of these portions on the focused scan beam are compared between successive windows.
Inventors:
Jean-Louis Jierra
Piel Berte
Black Brico
Piel Berte
Black Brico
Application Number:
JP4136083A
Publication Date:
December 14, 1994
Filing Date:
March 11, 1983
Export Citation:
Assignee:
Thomson-SEFS
International Classes:
G11B7/085; G11B7/00; G11B7/004; G11B7/007; G11B7/08; G11B7/09; G11B27/19; G11B27/30; (IPC1-7): G11B7/09
Domestic Patent References:
| JP52123205A | ||||
| JP55108968A | ||||
| JP5637A |
Attorney, Agent or Firm:
Yoshio Kawaguchi