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:
Dec. 04, 1984
Filed:
Oct. 07, 1983
Applicant:
Inventor:
Stephen A Benton, Lincoln, MA (US);
Assignee:
Polaroid Corporation, Cambridge, MA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; G02B / ; G03H / ;
U.S. Cl.
CPC ...
350-385 ; 350277 ; 350448 ; 40361 ;
Abstract
Apparatus for illuminating transmission holograms from the rear with an illumination source located in front of the hologram, comprising a reflector and a light trap adapted to be mounted behind the hologram at a location chosen to reflect light from the source through the hologram as though from a source behind the hologram, while reflecting ambient light from the direction of an observer of the hologram into the trap.