Photographic camera with exposure-control and focussing means

Details Photographic camera with exposure-control and focussing means Photographic camera with exposure-control and focussing means

1978-11-29

1980-10-28

Gellner, Michael L.

354 31, 354 50, 354 59, 354 60L, G03B 7081, G03B 7099, G03B 1318

Patent

active

042304008

ABSTRACT:
A focussing system emits an infrared light beam towards the subject, the reflected beam passing through an infrared filter and being projected by a spot optics as a small spot onto a pair of photosensitive elements. The spot optics shifts in a plane normal to the camera's optical axis in dependence upon rotation of the camera's focussing ring, to vary the distribution of the reflected beam onto the two elements, the distribution being equal between them when the state of focus is correct. A circuit derives, from the output signals of the two photosensitive elements, a state-of-focus signal used to automatically focus or else to indicate to the user the direction in which he should manually adjust focus. When focussing is finished, the photosensitive elements are disconnected from the focussing circuitry and connected to the camera's exposure-control circuitry, to thereby serve a dual function. The infrared filter moves out of the light path of the photosensitive elements. The spot optics is moved out of the light path of the photosensitive elements, so that for exposure control a larger light field can be established, or else an auxiliary optics moves into the light path to enlarge the light field in that manner.

REFERENCES:
patent: 3999192 (1976-12-01), Hosoe et al.
patent: 4047187 (1977-09-01), Mashimo

Affiliated with

Also associated with

Rating

Photographic camera with exposure-control and focussing means does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Photographic camera with exposure-control and focussing means, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photographic camera with exposure-control and focussing means will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-265544