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. 04, 1999
Filed:
Apr. 06, 1998
Fang-Chuan Ho, Hsinchu, TW;
June-Jei Huang, Taoyuan Hsien, TW;
Chi-Hua Lee, Taipei Hsien, TW;
Chun Chuan Lin, Chang Hua, TW;
Abstract
A polarization converter for unpolarized light. The polarization converter comprises a prism, a wedge, a set of lens arrays, a first reflecting plane, and a second reflecting plane. The wedge comprises a tilt plane. The tilt plane is coated with multi-layer polarization dichronic thin film. The set of lens arrays comprises a light distributor and a light integrator. The tilt plane of the wedge is glued on the first reflecting plane. A second reflecting plane is the unglued plane of the wedge. When a light beam is incident towards the incident plane, the first reflecting plane splits and polarizes the light beam into a first type polarized and a second type polarized lights. Through the multi-layer polarization dichronic thin film, about 99% of the first type polarized light is reflected, and about 99% of the second type polarized light is transmitted and incident on the second reflecting plane. By adjusting the critical angle between the second reflecting plane and the air, almost all the second type polarized light is reflected. The second type polarized light is then traveling through a half-wave plate and converted to a first type polarized light. A good uniformity and a high efficiency are obtained on the projection screen by the disposition of a light distributor lens array in front of the incident plane and a light integrator lens array on the emerging plane of the prism.