Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Optical Detector for Objects within an Adjustable Range

Not Accessible

Your library or personal account may give you access

Abstract

This paper describes a relatively simple system for detecting in-focus objects. A nonlinear, wide-area photocell with parallel-plate electrodes is vibrated axially behind a lens. When the object is out of focus, the photocell conductance varies at the vibration frequency. When the object is in focus, the photocell conductance signal “folds over” because of the symmetry about the image plane. This “fold over” is detected by electronic circuitry. The scheme is shown to operate over a wide field of view, and the photocell conductance as a function of axial position is given for a number of idealized object patterns. An experimental unit built on these principles is described briefly.

© 1964 Optical Society of America

Full Article  |  PDF Article
More Like This
Phenomena of Image Sharpness Recognition of CdS and CdSe Photoconductors

Paul Pargas
J. Opt. Soc. Am. 54(4) 516-519 (1964)

Threshold Size of a Moving Object as a Function of its Speed

Balraj Bhatia and C. A. Verghese
J. Opt. Soc. Am. 54(7) 948-950 (1964)

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (10)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (16)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved