Optical objective focus indicator and display

Details Optical objective focus indicator and display Optical objective focus indicator and display

1977-10-26

1978-09-26

Smith, Alfred E.

Radiant energy

Photocells; circuits and apparatus

Photocell controls its own optical systems

354 25, 354 60L, 356 4, 356227, 250201, 250204, H01J 3912, G01J 142

Patent

active

041173252

ABSTRACT:
Apparatus for indicating and displaying the focus of an optical objective and particularly a photographic camera. An image of the object is projected by means of the objective onto a scanning disk or plate where the light rays are divided into two separate light beams originating from two different areas of the exit pupil of the objective. Two photoelectric detectors are provided behind said scanning disk with one of said light beams impinging on one detector. Each detector delivers an electrical signal, the phase difference between these signals being a measure of the degree of focus of the objective. For indicating said degree of focus two LED's (Light Emitting Diodes) are provided which are so coupled that for focus (phase difference = null) they are equally luminous and that for lack of focus they indicate the direction of the image offset from the focusing plane and approximately also the magnitude of this offset on account of their special coupling and their change in luminosity which is independent of object brightness.

REFERENCES:
patent: 1145348 (1915-07-01), Carter
patent: 2007935 (1935-07-01), Ruben
patent: 3528350 (1970-09-01), Schmitt
patent: 3781110 (1973-12-01), Leitz et al.
patent: 3783270 (1974-01-01), Kamachi
patent: 3955892 (1976-05-01), Numata et al.

Affiliated with

Also associated with

Rating

Optical objective focus indicator and display does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Optical objective focus indicator and display, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical objective focus indicator and display will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2091856