Television – Video display – Projection device
Reexamination Certificate
2006-03-28
2006-03-28
Hsia, Sherrie (Department: 2614)
Television
Video display
Projection device
C348S781000, C359S650000, C359S772000, C359S780000, C359S649000
Reexamination Certificate
active
07019793
ABSTRACT:
Projection lens systems for use with cathode ray tube (CRT) projection televisions are provided which have positive first lens units (U1) and negative second lens units (U2) where the negative second lens units are customized in terms of at least one optical property for at least two of the colors of light produced by the CRTs with which the units are used. The at least one optical property is not spectral transmission, although the second lens units can also be customized for spectral transmission. As illustrated in FIGS.1B–1F and FIGS.8B–8F, such customization of a non-transmissive property provides an effective and cost effective approach for improving the color performance of CRT projection lens systems. Constructions for the positive first lens unit which improve image contrast and reduce manufacturing costs are also provided.
REFERENCES:
patent: 4699476 (1987-10-01), Clarke
patent: 4776681 (1988-10-01), Moskovich
patent: 4884879 (1989-12-01), Fukuda et al.
patent: 4948237 (1990-08-01), Hirata et al.
patent: 4950062 (1990-08-01), Kimura et al.
patent: 5029993 (1991-07-01), Fukuda et al.
patent: 5045930 (1991-09-01), Hasegawa
patent: 5055922 (1991-10-01), Wessling
patent: 5200814 (1993-04-01), Hirata et al.
patent: 5293226 (1994-03-01), Yamamoto et al.
patent: 5537167 (1996-07-01), Toide et al.
patent: 5633757 (1997-05-01), Park
patent: 5659424 (1997-08-01), Osawa et al.
patent: 6297860 (2001-10-01), Moskovich
patent: 6301056 (2001-10-01), Kreitzer
patent: 6324014 (2001-11-01), Moskovich
patent: 06082693 (1994-03-01), None
patent: 09138346 (1997-05-01), None
Dunham et al., “Minimax Approximation by a Semi-Circle”,SIAM J. Numer. Anal.,17:63-65, 1980.
Larson Michael B.
Moskovich Jacob
Wessling Richard J.
3M Innovative Properties Company
Hsia Sherrie
Jonas George W.
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