The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 08, 1980
Filed:
Dec. 19, 1977
Charles de Jesus, Lexington, MA (US);
William Hudspeth, Norwell, MA (US);
Polaroid Corporation, Cambridge, MA (US);
Abstract
A photo-electric pulse generating unit for monitoring the focus position of a camera objective lens driven in response to a range detection system and operative to generate pulses on rotation of a lens coupled encoder wheel having angularly spaced apertures movable in relation to a detector unit housing the photo-electric pulse generating unit. The unit mounts a pulse generating photo-transistor in alignment with a light source such that the photo-transistor is spaced behind an opaque wall opening to 'tunnel' light from a light source upon passing through an aperture in the encoder wheel. Light diffusing surface irregularities are provided to prevent impingement of reflected or ambient light on the photo-transistor.