Projection-type display apparatus

Details Projection-type display apparatus Projection-type display apparatus

2006-04-25

2006-04-25

Perkey, W. B. (Department: 2851)

Optics: image projectors

Light shield, mask, hood, or diaphragm

C353S037000, C353S099000, C359S227000, C359S739000, C348S771000, C349S007000

Reexamination Certificate

active

07033030

ABSTRACT:
An illuminating optical system for focusing a radiant light of a light source (1) onto a reflecting light valve (6) and a projection lens (7) for magnifying and projecting a reflected light from the reflecting light valve (6) onto a screen are provided, a diaphragm (31) is disposed at a substantially conjugate position of an entrance pupil of the projection lens (7) on an optical path of the illuminating optical system, the diaphragm (31) has an opening whose area is changed by a light-shielding member, and a shape of a shielded portion of the diaphragm (31) shielded by the light-shielding member is rotationally asymmetric to an optical axis (12) of the illuminating optical system. Accordingly, shielding of necessary light can be better avoided compared with a diaphragm for changing the light-shielding area in a rotationally symmetric manner, for example, a diaphragm for narrowing the opening concentrically, making it possible to improve contrast performance while minimizing brightness reduction.

REFERENCES:
patent: 5442414 (1995-08-01), Janssen et al.
patent: 5743612 (1998-04-01), Matsuda et al.
patent: 5760875 (1998-06-01), Daijogo et al.
patent: 6220730 (2001-04-01), Hewlett et al.
patent: 6264333 (2001-07-01), Iizuka
patent: 6357878 (2002-03-01), Sawamura
patent: 6371617 (2002-04-01), Nishida et al.
patent: 6382799 (2002-05-01), Nishikawa et al.
patent: 6454417 (2002-09-01), Takamoto et al.
patent: 6607277 (2003-08-01), Yokoyama et al.
patent: 6607280 (2003-08-01), Koyama et al.
patent: 6637894 (2003-10-01), Dewald et al.
patent: 2002/0027720 (2002-03-01), Nishikawa et al.
patent: 2002/0036833 (2002-03-01), Miyata et al.
patent: 2002/0044261 (2002-04-01), Ouchi et al.
patent: 8-129138 (1996-05-01), None
patent: 9-5000738 (1997-09-01), None
patent: 2000-47326 (2000-02-01), None
patent: 2000-206451 (2000-07-01), None
patent: 2000-206455 (2000-07-01), None
patent: 2000-258703 (2000-09-01), None
patent: 2000-338428 (2000-12-01), None
patent: 2001-42256 (2001-02-01), None
patent: 2002-6257 (2002-01-01), None
patent: 2002-72128 (2002-03-01), None
patent: 2002-107662 (2002-04-01), None
patent: 2002-214564 (2002-07-01), None

Affiliated with

Also associated with

Rating

Projection-type display apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Projection-type display apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Projection-type display apparatus will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3597119