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:
Jul. 12, 1988
Filed:
Jul. 02, 1987
Applicant:
Inventors:
Hideaki Nakatsuka, Mobara, JP;
Mikio Kanazaki, Mobara, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02F / ; G02B / ; G02B / ;
U.S. Cl.
CPC ...
3503 / ; 350445 ; 350452 ; 350334 ; 350345 ;
Abstract
There is disclosed a liquid crystal display device having very uniform contrast ratio for use with such a projector as an overhead projector. The liquid crystal display device comprises a liquid crystal display cell having a thin film of liquid crystal material sandwiched between transparent electrodes formed on opposing transparent substrates and a Fresnel collimating lens disposed before the cell in the direction of light traveling through the cell and for collimating the light in parallel light beams from a condenser lens in the projector.