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US006582081B2
(12) United States Patent ao) Patent No.: us 6,582,081 B2
Seo et al. (45) Date of Patent: Jun. 24,2003
(54) PROJECTION DISPLAY DEVICE
(75) Inventors: Eun-Seong Seo, Seoul (KR);
Joon-Chan Park, Dongan-gu (KR)
(73) Assignee: Samsung SDI Co., Ltd., Suwon (KR)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.
(21) Appl. No.: 10/114,324
(22) Filed: Apr. 3, 2002
(65) Prior Publication Data
US 2002/0154273 Al Oct. 24, 2002 (30) Foreign Application Priority Data
Apr. 24, 2001 (KR) 2001-22100
(51) Int. CI.7 G03B 21/14
(52) U.S. CI 353/20; 353/31
(58) Field of Search 353/20, 33, 31,
353/81; 359/483
(56) References Cited
U.S. PATENT DOCUMENTS
5,042,921 A * 8/1991 Sato et al 349/9
The present invention discloses a projection display device, including a light source supplying light having a s-wave light and a p-wave light; a first polarizing beam splitter including a reflecting surface, transmitting the p-wave light and reflecting the s-wave light; a retardation film arranged between the light source and the polarizing beam splitter to cover a portion of a front surface of the polarizing beam splitter, and converting the s-wave light into the p-wave light and the p-wave light into the s-wave light; a mirror re-reflecting the s-wave light reflected from the reflecting surface of the first polarizing beam splitter toward the reflecting surface of the first polarizing beam splitter, so that the s-wave light directs toward the retardation film.
20 Claims, 6 Drawing Sheets
