Title:
AUTOMATIC LIGHT BEAM TRACKING DEVICE
Document Type and Number:
Japanese Patent JP3214935
Kind Code:
B2
Abstract:
PURPOSE: To suppress the deterioration in the responsiveness or normal deviation characteristic of a control system due to the change of a transmitting distance, and to improve the stability of the control system.
CONSTITUTION: A tracking mirror 11 arranged in a light beam adjusting mechanism 24 is provided on the optical path of a received light L, and a four-division photoelectric detector 13 is provided through an optical system 12 in the reflecting direction of the tracking mirror 11. The output of the four-division photoelectric detector 13 is connected to a control part 23, and the output of the control part 23 is connected to the light beam adjusting mechanism 24. In a tracking state, a direct current signal from a command signal generator 18 in the control part 23 is added to a tracking error angle, an the tracking mirror 11 is changed by only a micro-angle. Then, the changing amount of the gain of the four-division photoelectric detector 13 corresponding to the changing amount is detected, the gain for canceling the changing amount is calculated by a calibration arithmetic part 16, and the gain of a compensating element 27 is changed to the calculated value. Thus, an open loop gain can be always held to be the optimal value.
Inventors:
Takehide Hamuro
Application Number:
JP32869992A
Publication Date:
October 02, 2001
Filing Date:
November 13, 1992
Export Citation:
Assignee:
Canon Inc
International Classes:
G02B7/28; G05D3/00; H04B10/079; H04B10/11; H04B10/112; (IPC1-7): H04B10/105; G02B7/28; G05D3/00; H04B10/10; H04B10/22
Domestic Patent References:
| JP2186311A | ||||
| JP4155409A | ||||
| JP63172115A |
Attorney, Agent or Firm:
Yukihiko Hibiya