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. 07, 1998
Filed:
Jul. 11, 1995
Nobuhiko Ichikawa, Tokyo, JP;
Tsuyoshi Hotta, Tokyo, JP;
Dai Nippon Printing Co., Ltd., Tokyo, JP;
Abstract
A liquid crystal display apparatus and liquid crystal projection display apparatus, which employ a hologram color filter, and which are designed so that the illuminating light utilization efficiency is improved to a considerable extent, and that a color image can be faithfully displayed with excellent color reproducibility without uneven color or other similar problem. A color liquid crystal display apparatus (11) has a hologram (5), which diffractively disperses incident light so as to emanate light rays in different wavelength regions at a predetermined spatial period, as a color filter, and a liquid crystal display device (6). The display apparatus (11) is illuminated by white parallel back light (3) from an illuminator (14). A displayed image which is modulated in the color liquid crystal display apparatus (11) is passed through a field lens, which is disposed in the vicinity of the display apparatus (11), and formed as an enlarged image on a screen (19) for display through a projection lens (18). A short-wavelength cut-off filter whose transmittance for a wavelength not longer than 430 nm is not higher than 5% is disposed at a position in an optical path extending from a lamp (15) to the screen (19), thereby preventing crosstalk of colors which might otherwise occur when light which should be incident on a pixel assigned to display blue undesirably enters a pixel which is adjacent to the pixel for blue, and thus making it possible to display a faithful color image.