US6334685B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Segmented light pipe apparatus and method for increasing luminous efficiency of single light-valve, color video projection displays
Assignee: Seiko Epson Corp
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Filing: 2000-03-23
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Granted: 2002-01-01
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Expires: 2020-03-23
Abstract
Abstract A color sequential video projector ( 10 ) employs a color modulating device ( 22 ) and a segmented light pipe ( 30 ) that coact to provide a high luminous efficiency. The color modulating device splits polychromatic light into three different colored light beams ( 24, 26, 28 ) that are positionally stationary, but alternate mutually exclusive colors sequentially with time such that each pixel of a light valve ( 48 ) is exposed to all three colors during an image frame time. The segmented light pipe receives the three light beams and forms three adjacent color bands that are precisely aligned on the light valve. Because all three colors of light are constantly illuminating the light valve, light losses are substantially eliminated. The color modulating device employs multiple color wheels ( 82, 84, 86 ) each having filter segments ( 90, 92, 94 ) that form the three light beams by reflecting the alternating, mutual exclusive colors as the wheels rotate. Alternative embodiments employ one, two, or three color wheels having flat or conically-shaped filter segment surfaces. The segmented light pipe includes three rectangular glass cores ( 70, 72, 74 ) surrounded by a low index cladding ( 78 ) and having their abutting faces ( 76 ) coated with a thin, low refraction index coating. The light pipe input apertures ( 32, 34, 36 ) receive three roughly shaped light beams, homogenize them, and provide at three output apertures ( 38, 40, 42 ) uniformly bright rectangular light beams. A precision achromatic lens ( 44 ) images the uniform light beams onto the light valve such that seams between the beams are imaged to within one micron of accuracy and are parallel to the light valve pixel rows.
Inventors
- 👤 David E. Slobodin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:40
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3111; H04N9/3117
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
182 words
A color video projector apparatus having high luminous efficiency, comprising: a light source producing polychromatic light and having a predetermined power dissipation; a color modulating device receiving the polychromatic light and separating it into first, second, and third light beams comprising alternating and mutually exclusive first, second, and third colors; a light pipe having first, second, and third input apertures positioned to receive the respective first, second, and third light beams, the light pipe homogenizing the first, second, and third light beams and propagating them from respective first, second, and third output apertures; a light valve having an addressable area that is sub-addressable as first, second, and third addressable segments that respectively receive from the light pipe the first, second, and third light beams; a controller conveying to the first, second, and third addressable segments colored video data corresponding with the sequentially alternating and mutually exclusive first, second, and third colors propagated by the color modulating device such that the light valve propagates a polychromatic image; and a projection lens focusing the polychromatic image on a projection screen with a predetermined luminance.
Claim 2
Dependent Claim
182 words
A color video projector apparatus having high luminous efficiency, comprising: a light source producing polychromatic light and having a predetermined power dissipation; a color modulating device receiving the polychromatic light and separating it into first, second, and third light beams comprising alternating and mutually exclusive first, second, and third colors; a light pipe having first, second, and third input apertures positioned to receive the respective first, second, and third light beams, the light pipe homogenizing the first, second, and third light beams and propagating them from respective first, second, and third output apertures; a light valve having an addressable area that is sub-addressable as first, second, and third addressable segments that respectively receive from the light pipe the first, second, and third light beams; a controller conveying to the first, second, and third addressable segments colored video data corresponding with the sequentially alternating and mutually exclusive first, second, and third colors propagated by the color modulating device such that the light valve propagates a polychromatic image; and a projection lens focusing the polychromatic image on a projection screen with a predetermined luminance.
Claim 3
Dependent Claim
18 words
The apparatus of claim 1 in which the first second and third colors are red, green, and blue.
Claim 4
Dependent Claim
17 words
The apparatus of claim 1 in which the light source includes an arc lamp and a reflector.
Claim 5
Dependent Claim
27 words
The apparatus of claim 1 in which the predetermined power dissipation is less than about 120 watts, and the predetermined luminance is greater than about 1,200 lumens.
Claim 6
Dependent Claim
18 words
The apparatus of claim 1 in which the light valve includes a DMD or a reflective CMOS device.
Claim 7
Dependent Claim
112 words
The apparatus of claim 1 in which the color modulating device further comprises: a first set of moving filter segments that sequentially receive the polychromatic light and form the first light beam by reflecting respective ones of the first, second, and third colors while transmitting the other two colors; a second set of filter segments moving in synchronism with the first set of moving filter segments to receive the other two colors and form the second light beam by reflecting respective ones of the other two colors while transmitting a remaining color; and an optical device that receives the remaining color and forms the third light beam by reflecting the remaining color.
Claim 8
Dependent Claim
23 words
The apparatus of claim 6 in which the first and second sets of filter segments are rotated by at least one color wheel.
Claim 9
Dependent Claim
13 words
The apparatus of claim 6 in which the optical device is a mirror.
Claim 10
Dependent Claim
20 words
The apparatus of claim 1 further including a relay lens that focuses the polychromatic light on the color modulating device.
Claim 11
Dependent Claim
76 words
The apparatus of claim 1 in which the first, second, and third addressable segments of the light valve are adjacent rectangular areas having seams between them and the apparatus further includes an achromatic lens positioned between the light pipe output apertures and the light valve to precisely focus the first, second, and third light beams on the respective first, second, and third addressable segments such that the seams are not visible in the projected polychromatic image.
Claim 12
Dependent Claim
31 words
The apparatus of claim 1 in which the first, second, and third input apertures of the light pipe are flared apart to receive the respective first, second, and third light beams.
Claim 13
Dependent Claim
28 words
The apparatus of claim 1 in which the segmented light pipe further includes three cross-sectionally rectangular, optically transparent cores having abutting surfaces that are coated with reflective film.
Claim 14
Independent Claim
121 words
A method of projecting polychromatic video images with a high luminous efficiency, comprising: producing polychromatic light with a light source having a predetermined power dissipation; separating the polychromatic light into first, second, and third light beams comprising alternating and mutually exclusive first, second, and third colors; homogenizing the first, second, and third light beams; imaging the homogenized first, second, and third light beams onto first, second, and third addressable segments of a light valve; conveying to the first, second, and third addressable segments colored video data corresponding with the sequentially alternating and mutually exclusive first, second, and third colors such that the light valve propagates a polychromatic image; and projecting the polychromatic image on a projection screen with a predetermined luminance.
Claim 15
Independent Claim
121 words
A method of projecting polychromatic video images with a high luminous efficiency, comprising: producing polychromatic light with a light source having a predetermined power dissipation; separating the polychromatic light into first, second, and third light beams comprising alternating and mutually exclusive first, second, and third colors; homogenizing the first, second, and third light beams; imaging the homogenized first, second, and third light beams onto first, second, and third addressable segments of a light valve; conveying to the first, second, and third addressable segments colored video data corresponding with the sequentially alternating and mutually exclusive first, second, and third colors such that the light valve propagates a polychromatic image; and projecting the polychromatic image on a projection screen with a predetermined luminance.
Claim 16
Dependent Claim
18 words
The method of claim 13 in which the first second and third colors are red, green, and blue.
Claim 17
Dependent Claim
27 words
The method of claim 13 in which the predetermined power dissipation is less than about 120 watts, and the predetermined luminance is greater than about 1,200 lumens.
Claim 18
Dependent Claim
18 words
The method of claim 13 in which the light valve includes a DMD or a reflective CMOS device.
Claim 19
Dependent Claim
103 words
The method of claim 13 in which separating the polychromatic light further comprises: moving a first set of filter segments to sequentially receive the polychromatic light and form the first light beam by reflecting respective ones of the first, second, and third colors while transmitting the other two colors; moving a second set of filter segments in synchronism with the first set of moving filter segments to receive the other two colors and form the second light beam by reflecting respective ones of the other two colors while transmitting a remaining color; and reflecting the remaining color to form the third light beam.
Claim 20
Dependent Claim
23 words
The method of claim 17 in which the first and second sets of filter segments moved by rotating at least one color wheel.
Claim 21
Dependent Claim
15 words
The method of claim 17 in which the reflecting is carried out by a mirror.
Claim 22
Dependent Claim
79 words
The method of claim 13 in which the homogenizing and imaging of the first, second, and third light beams further comprise providing a segmented light pipe having first, second, and third input apertures positioned to receive the respective first, second, and third light beams, and having respective first, second, and third cross-sectionally rectangular output apertures positioned for projecting the homogenized first, second, and third light beams onto the respective first, second, and third addressable segments of the light valve.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-12-31 | 2005-07-02 | 2006-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-12-31 | 2009-07-02 | 2010-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-12-31 | 2013-07-02 | 2014-01-01 | $7700.00 | Window Closed / Lapsed |