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:
May. 13, 1980
Filed:
Apr. 26, 1978
Applicant:
Inventors:
James H Burbo, Roanoke, VA (US);
Louis P Hartman, Roanoke, VA (US);
Assignee:
International Telephone and Telegraph Corporation, New York, NY (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02C / ; G02B / ;
U.S. Cl.
CPC ...
350159 ; 351 49 ;
Abstract
A filter arrangement is described which is incorporated with a night vision device. The filter arrangement consists of a variable density polaroid filter array and a blue-green filter all contained in a common housing and directed along a given optical path. The filter arrangement serves to control the amount of light directed to an input port of a night vision device such as a pair of goggles. In this manner, a user can be trained to employ the night vision device under direct supervision in daylight conditions and by variation of the polarizing plates is enabled to simulate nighttime conditions.