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. 16, 2000
Filed:
Jul. 22, 1998
Masanori Ogino, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
White light is input to light diffracting means so composed as to have a structure including macro prisms combined with a lenticular structure and include diffraction gratings at a microscopic level. As the height (h(x)) of unit steps of said diffraction grating is modulated at every period of arranged pixels, the output diffracted light is decomposed into three primary colors, and guided with highly accurate matching to the three respective primary color pixels of a liquid crystal panel means. In the pitch modulation type diffraction grating of the prior art, it was basically impossible to avoid the defect that the converged positions of a red light ray and a blue light ray deviate about 30%. In contrast, according to the arrangement of this invention, it becomes possible to eliminate the deviation of the converged positions of not only the green light ray but the red light ray and the blue light ray, making it possible to provide a single plate type color liquid crystal display apparatus with high light utilization efficiency.