Patent US5592238A successfully refreshed from Google Patents.
US5592238A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Field-sequential projection display
Assignee: Hitachi Ltd
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Filing: 1995-05-30
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Granted: 1997-01-07
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Expires: 2015-05-30
Abstract
Abstract A single-tube type projection display with high light efficiency includes phosphors of three primary colors formed on upper, middle and lower portions of a faceplate of a CRT. Images of three colors are projected on the phosphor layers, and a color picture is obtained by overlapping the three color images on the screen by the projection lenses.
Inventors
- 👤 Masanori Ogino
- 👤 Tetsuo Asano
- 👤 Yasuhiko Uehara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:24
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
124 words
A single-tube type projection display comprising: a screen; three projection lenses; a parallel-to-serial scan-conversion means; and a vertically-arranged three-primary-color phosphor CRT, wherein said CRT has phosphor layers for three primary colors formed on upper, middle and lower portions of a faceplate thereof, the middle portion of the faceplate corresponding to a green phosphor having a longest after-glow duration among the three primary colors, wherein images of the three primary colors are projected field-sequentially on said phosphor layers with one electron, a green color image being displayed prior to images of other of the three primary colors, and wherein by overlapping said images of the three primary colors on said screen by said three projection lenses, a color picture can be formed on said screen.
Claim 2
Dependent Claim
124 words
A single-tube type projection display comprising: a screen; three projection lenses; a parallel-to-serial scan-conversion means; and a vertically-arranged three-primary-color phosphor CRT, wherein said CRT has phosphor layers for three primary colors formed on upper, middle and lower portions of a faceplate thereof, the middle portion of the faceplate corresponding to a green phosphor having a longest after-glow duration among the three primary colors, wherein images of the three primary colors are projected field-sequentially on said phosphor layers with one electron, a green color image being displayed prior to images of other of the three primary colors, and wherein by overlapping said images of the three primary colors on said screen by said three projection lenses, a color picture can be formed on said screen.
Claim 3
Dependent Claim
19 words
A single-tube type projection display according to claim 1, further comprising an electric circuit including said parallel-to-serial scan-conversion means.
Claim 4
Dependent Claim
36 words
A single-tube type projection display according to claim 1, wherein said phosphor faceplate of said CRT is formed with a radius of curvature one to two times a distance between said phosphor faceplate and said screen.
Claim 5
Dependent Claim
37 words
A single-tube type projection display according to claim 3, further comprising a reflecting mirror altering a projection light path, wherein at least one of spaces on the left-hand and right-hand sides below said screen includes a shelf.
Claim 6
Dependent Claim
22 words
A single-tube type projection display according to claim 1, wherein an output field-scanning frequency is faster than an input signal field-scanning frequency.
Claim 7
Dependent Claim
24 words
A single-tube type projection display according to claim 5, wherein the output field-scanning frequency is two times faster than the input signal field-scanning frequency.
Claim 8
Dependent Claim
37 words
A single-tube type projection display according to claim 1, further comprising a reflecting mirror altering a projection light path, wherein at least one of spaces on the left-hand and right-hand sides below said screen includes a shelf.
Claim 9
Dependent Claim
19 words
A single-tube type projection display according to claim 1, further comprising a reflecting mirror altering a projection light path.
Claim 10
Dependent Claim
19 words
A single-tube type projection display according to claim 3, further comprising a reflecting mirror altering a projection light path.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-01-07 | 2000-07-08 | 2001-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-01-07 | 2004-07-08 | 2005-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-01-07 | 2008-07-08 | 2009-01-07 | $7700.00 | Window Closed / Lapsed |