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.:

US 7145728 B1

PDF
Full Text
Expired
Date of Patent:
Dec. 05, 2006

Filed:

May. 07, 2002
Applicant:

Yong-dok Cha, Gyeonggi-do, KR;

Inventor:

Yong-dok Cha, Gyeonggi-do, KR;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B 27/14 (2006.01);
U.S. Cl.
CPC ...
Abstract

A projection apparatus including a light source which generates light beams, an optical projection system which projects the light beams generated by the light source onto a screen, and a reflection device which is positioned between the light source and the optical projection system. The reflection device includes a plurality of mirrors capable of reflecting incident beams generated by the light source to travel toward the optical projection system. The projection apparatus also includes an optical illumination system which is positioned in an optical path between the light source and the reflection device and is tilted or decentered with respect to the optical axis of the light source to allow light beams generated by the light source to enter the reflection device at a predetermined angle. Since the optical paths of the optical projection system and the optical illumination system can be separated from each other by installing lenses in the optical illumination system, it is possible to manufacture the projection apparatus through a simple assembly and improve optical efficiency and a contrast ratio.


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