Title:
AUTOFOCUSING CONTROLLER
Document Type and Number:
Japanese Patent JP3179824
Kind Code:
B2
Abstract:
PURPOSE: To surely perform focus setting even when switching timing to a focus servo system somewhat lags without being affected by the position of an objective lens.
CONSTITUTION: This controller is provided with a circuit 22 which generates a focus error signal from a current flowing in a PIN photodiode 21, a position detector 73 which detects the position of the objective lens 17 and a position signal generation circuit 74, a position control circuit 78 which controls the position of the objective lens 17 based on a position command signal generated by a volume 77, a changeover switch SW2 which switches a position control system and the focus servo system, a position compensating means consisting of a CPU 82 for making the output voltage of the position control circuit 78 to the switch SW2 near to zero without depending on the position of the objective lens 17, a RAM 83, and an adder 80, etc., and a gain changeover switch SW3 which switches the gain of the focus error signal generation circuit 22 at the time of switching from the position control system to the focus servo system.
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Inventors:
Hirohisa Mega
Application Number:
JP31880591A
Publication Date:
June 25, 2001
Filing Date:
December 03, 1991
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
G01B11/24; G02B7/28; G11B7/085; G11B7/09; (IPC1-7): G02B7/28
Domestic Patent References:
| JP3110406A | ||||
| JP231333A | ||||
| JP1220227A | ||||
| JP6246443A |
Attorney, Agent or Firm:
Masaru Ishihara