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. 06, 1999
Filed:
May. 07, 1997
Motoi Ueda, Kanagawa-ken, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A color projection display device separates light into the colors of red, green and blue. Each of the color components is modulated, superimposed with the other components again and projected. The device provides color picture images with few irregularities in illumination intensity. Polarizing beam splitters used for modulation of the colors are constructed from base materials having a minimum absolute photoelasticity constant value at different wavelengths. Thus, the absolute photoelasticity constant value of the base material for a particular wavelength of light that is separated by the polarizing beam splitter can be made small and double refractions, resulting from stress, are unlikely to occur in any of the components. As a result, a disturbance in the polarization and separation performance is unlikely to occur, and irregularities in the illumination intensity can be reduced.