Automatic focusing device

Details Automatic focusing device Automatic focusing device

1995-06-07

1997-02-04

Adams, Russell E.

Photography

With exposure objective focusing means, focusing aid, or...

Lens drive circuit or motor structure

G03B 1336

Patent

active

056003978

ABSTRACT:
An automatic focusing device in which when a lens shifting range is arbitrarily limited and set with respect to the distance to a target object, the defocus amount and lens position are automatically detected, and the image plane shifting amount corresponding to the limited lens shifting range is calculated. Then, the corresponding image shifting amount and the detected defocus amount are compared. As a result of such comparison, if the defocus amount is found smaller, i.e., the target object is within the lens shift limiting range, the lens is shifted by the lens shifting amount thus calculated so as to perform focusing. If the defocus amount is found larger, i.e., the target object is outside the lens shift limiting range, the driving of the driving device is disabled so as not to shift the lens. If the defocus amount is found larger and the lens shifting is disabled, the defocus amount is again detected. The image shifting amount and lens shifting amount are calculated by the standard image plane shifting conversion coefficient and correction coefficient.

REFERENCES:
patent: 4434362 (1984-02-01), Wilwerding
patent: 4482234 (1984-11-01), Takagi et al.
patent: 4525053 (1985-06-01), Shiokama
patent: 4792819 (1988-12-01), Akashi

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-683978