Automatic focusing device

Details Automatic focusing device Automatic focusing device

1984-09-04

1986-11-25

McElheny, Jr., Donald

Dynamic information storage or retrieval

Control of storage or retrieval operation by a control...

Mechanism control by the control signal

369 46, 369120, G11B 700

Patent

active

046253033

ABSTRACT:
An automatic focusing device for controlling the position of the objective lens relative to the information recording medium is provided with an astigmatic optical system which receives the reflected light beam reflected by the information recording medium. The light receiving surface of a light detector included in the astigmatic optical system consists of a central light receiving section formed approximatley symmetrically with respect to two axes intersecting each other perpendicularly and having a constricted central portion, and two side light receiving sections formed approximately symmetrically with respect to those two axes and opposite to each other. The light reception signal given by the central light receiving section and the light reception signals given by the side light receiving sections are fed to a focal position detecting circuit which gives a signal corresponding to the deviation of the objective lens from the focused position, on the basis of the light reception signals given thereto.

REFERENCES:
patent: 4023033 (1977-05-01), Bricot et al.
patent: 4051527 (1977-09-01), Braat
patent: 4410969 (1983-10-01), Maeda
patent: 4414658 (1983-11-01), Yoshida

Affiliated with

Also associated with

Rating

Automatic focusing device does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Automatic focusing device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automatic focusing device will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1161947