Patent US6046858A successfully refreshed from Google Patents.
US6046858A
Expired / Lapsed
US
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Light separation and recombination system for an off-axis projector
Assignee: Corning Oca Corp
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Filing: 1997-10-16
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Granted: 2000-04-04
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Expires: 2017-10-16
Abstract
Abstract A color separation and recombination system separates a beam of white light traveling along an optical axis into three differently colored light beams. The system then independently modulates each colored beam and recombines the colored beams to create a color image. The system includes a crossed pair of dichroic filters to separate the beam of white light and to recombine the modulated bundles. The system also includes a pair of aberration-compensating elements that equalize the optical thickness of glass through which each light bundle passes. This equalization of optical thickness equalizes the aberration induced into each bundle. In another embodiment the beam of white light is polarized before separation. The polarities of the colored light beams are then modulated using a spatial light modulator. An analyzer and half-wave plate are provided between the spatial light modulator and the crossed dichroic filters to pass only a portion of the modulated light. The half-wave plate ensures that the modulated light incident on the crossed dichroic filters is of the same polarity as the polarized white light separated by the crossed dichroic filters.
Inventors
- 👤 Bradley A. Scott
- 👤 William L. DeBoynton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:56
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3105
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
168 words
A color separation system configured to separate a beam of white light traveling along an optical axis into first, second, and third components having respective first, second, and third colors, the system comprising: a first dichroic filter positioned along the optical axis and having a first optical thickness, the first dichroic filter adapted to reflect the first component along a first path not parallel to the optical axis and to pass the second and third components; a second dichroic filter positioned along the optical axis and having a second optical thickness, the second dichroic filter adapted to reflect the second component along a second path not parallel to the optical axis and to pass the first and third components; a first aberration-compensating element positioned in the first path, the first aberration-compensating element having a third optical thickness equal to the second optical thickness; and a second aberration-compensating element positioned in the second path, the second aberration-compensating element having a fourth optical thickness equal to the first optical thickness.
Claim 2
Dependent Claim
168 words
A color separation system configured to separate a beam of white light traveling along an optical axis into first, second, and third components having respective first, second, and third colors, the system comprising: a first dichroic filter positioned along the optical axis and having a first optical thickness, the first dichroic filter adapted to reflect the first component along a first path not parallel to the optical axis and to pass the second and third components; a second dichroic filter positioned along the optical axis and having a second optical thickness, the second dichroic filter adapted to reflect the second component along a second path not parallel to the optical axis and to pass the first and third components; a first aberration-compensating element positioned in the first path, the first aberration-compensating element having a third optical thickness equal to the second optical thickness; and a second aberration-compensating element positioned in the second path, the second aberration-compensating element having a fourth optical thickness equal to the first optical thickness.
Claim 3
Dependent Claim
32 words
The system of claim 1, wherein at least one of the first and second aberration-compensating elements is a mirror comprising a transparent plate having a thickness one half the first optical thickness.
Claim 4
Dependent Claim
26 words
The system of claim 1, further comprising a light modulator positioned along the first path, the light modulator configured to receive and modulate the first component.
Claim 5
Dependent Claim
28 words
The system of claim 3, further comprising a second light modulator positioned along the second path, the second light modulator configured to receive and modulate the second component.
Claim 6
Dependent Claim
35 words
The system of claim 4, further comprising a third light modulator positioned along the optical axis after the first and second dichroic filters, the third light modulator configured to receive and modulate the third component.
Claim 7
Dependent Claim
16 words
The system of claim 5, wherein the first-mentioned, second, and third light modulators comprise liquid crystal.
Claim 8
Dependent Claim
30 words
The system of claim 5, wherein the first-mentioned, second, and third light modulators comprise respective first, second, and third reflective surfaces adapted to reflect the first, second, and third components.
Claim 9
Dependent Claim
13 words
The system of claim 1, wherein the first and second dichroic filters intersect.
Claim 10
Dependent Claim
22 words
The system of claim 1, further comprising a polarizer disposed in the optical path and an analyzer disposed in a projection path.
Claim 11
Dependent Claim
23 words
The system of claim 9, further comprising a half-wave plate positioned in the projection path between the analyzer and the first dichroic filter.
Claim 12
Dependent Claim
146 words
An image projector comprising: a light source; a polarizer; a collimating lens disposed between the light source and the polarizer, the collimating lens configured to collimate light from the light source and to shine the collimated light through the polarizer; a light modulator positioned to receive the collimated light from the polarizer along an illumination path, the light valve positioned to pass the collimated light; a reflective surface configured to receive the collimated light from the light valve and to reflect the collimated light back through the light valve along a projection path not parallel to the illumination path; an analyzer positioned along the projection path to receive and analyze the reflected collimated light from the light valve; a dichroic filter positioned along the projection path to receive the reflected and analyzed collimated light; and a half-wave plate disposed between the analyzer and the dichroic filter.
Claim 13
Dependent Claim
146 words
An image projector comprising: a light source; a polarizer; a collimating lens disposed between the light source and the polarizer, the collimating lens configured to collimate light from the light source and to shine the collimated light through the polarizer; a light modulator positioned to receive the collimated light from the polarizer along an illumination path, the light valve positioned to pass the collimated light; a reflective surface configured to receive the collimated light from the light valve and to reflect the collimated light back through the light valve along a projection path not parallel to the illumination path; an analyzer positioned along the projection path to receive and analyze the reflected collimated light from the light valve; a dichroic filter positioned along the projection path to receive the reflected and analyzed collimated light; and a half-wave plate disposed between the analyzer and the dichroic filter.
Claim 14
Dependent Claim
15 words
The projector of claim 11, wherein the light valve comprises a transmissive liquid crystal material.
Claim 15
Dependent Claim
12 words
The projector of claim 11, wherein the polarizer is a linear polarizer.
Claim 16
Dependent Claim
12 words
The projector of claim 11, wherein the analyzer is a linear polarizer.
Claim 17
Dependent Claim
131 words
A color separation system for a projector, the system comprising: a light source producing visible light and shining the light along an illumination path; a polarizer positioned in the illumination path to receive and polarize the light from the light source to provide polarized light of a first polarization; a reflective surface configured to receive the polarized light from the polarizer and to reflect the light along a projection path not parallel to the illumination path; an analyzer positioned along the projection path to receive and analyze the reflected light from the analyzer, wherein the analyzer is configured to pass reflected light of a second polarization; and a half-wave plate positioned along the projection path and configured to change the polarization of the light from the analyzer to the first polarization.
Claim 18
Dependent Claim
131 words
A color separation system for a projector, the system comprising: a light source producing visible light and shining the light along an illumination path; a polarizer positioned in the illumination path to receive and polarize the light from the light source to provide polarized light of a first polarization; a reflective surface configured to receive the polarized light from the polarizer and to reflect the light along a projection path not parallel to the illumination path; an analyzer positioned along the projection path to receive and analyze the reflected light from the analyzer, wherein the analyzer is configured to pass reflected light of a second polarization; and a half-wave plate positioned along the projection path and configured to change the polarization of the light from the analyzer to the first polarization.
Claim 19
Dependent Claim
17 words
The system of claim 15, wherein the first polarization is P-type and the second polarization is S-type.
Claim 20
Dependent Claim
19 words
The system of claim 15, further comprising a color separator configured to separate the polarized light from the polarizer.
Claim 21
Dependent Claim
21 words
The system of claim 17, wherein the color separator is configured to receive the light from the half-wave plate for recombination.
Claim 22
Independent Claim
76 words
A method of projecting an image onto a display surface, the method comprising: directing a beam of light along an illumination path; separating the beam into a plurality of different colored beams; polarizing each of the colored beams; modulating the polarities of selected portions of each of the colored beams; reflecting the modulated colored beams along a projection path not parallel to said illumination path; analyzing the modulated colored beams; and recombining the analyzed colored beams.
Claim 23
Independent Claim
76 words
A method of projecting an image onto a display surface, the method comprising: directing a beam of light along an illumination path; separating the beam into a plurality of different colored beams; polarizing each of the colored beams; modulating the polarities of selected portions of each of the colored beams; reflecting the modulated colored beams along a projection path not parallel to said illumination path; analyzing the modulated colored beams; and recombining the analyzed colored beams.
Claim 24
Independent Claim
72 words
A method of projecting an image onto a display surface, the method comprising: directing a beam of light along an illumination path; separating the beam into a plurality of different colored beams; polarizing each of the colored beams; modulating the polarities of selected portions of each of the colored beams; analyzing the modulated colored beams; rotating the polarity of at least one of the colored beams; and recombining the analyzed colored beams.
Claim 25
Independent Claim
72 words
A method of projecting an image onto a display surface, the method comprising: directing a beam of light along an illumination path; separating the beam into a plurality of different colored beams; polarizing each of the colored beams; modulating the polarities of selected portions of each of the colored beams; analyzing the modulated colored beams; rotating the polarity of at least one of the colored beams; and recombining the analyzed colored beams.
Claim 26
Dependent Claim
66 words
A color separation and recombination system comprising: a light source for emitting a beam of visible light; means for separating the beam into a plurality of different colored beams; means for polarizing each of the colored beams; means for modulating the polarities of selected portions of each of the colored beams; means for analyzing the modulated colored beams; and means for recombining the analyzed colored beams.
Claim 27
Dependent Claim
66 words
A color separation and recombination system comprising: a light source for emitting a beam of visible light; means for separating the beam into a plurality of different colored beams; means for polarizing each of the colored beams; means for modulating the polarities of selected portions of each of the colored beams; means for analyzing the modulated colored beams; and means for recombining the analyzed colored beams.
Claim 28
Dependent Claim
22 words
A color separation of recombination system according to claim 21, further comprising means for rotating the polarity of the analyzed colored beams.
Claim 29
Dependent Claim
22 words
A color separation and recombination system according to claim 21, wherein the means for analyzing the modulated colored beams is a polarizer.
Claim 30
Dependent Claim
51 words
An image projector comprising: a light source; a color separator; a reflective light modulator disposed to receive light along a first direction and to reflect the modulated light along a second direction not parallel to said first direction; and a polarizer disposed between said color separator and said reflective light modulator.
Claim 31
Dependent Claim
51 words
An image projector comprising: a light source; a color separator; a reflective light modulator disposed to receive light along a first direction and to reflect the modulated light along a second direction not parallel to said first direction; and a polarizer disposed between said color separator and said reflective light modulator.
Claim 32
Dependent Claim
21 words
The image projector of claim 24, further comprising an analyzer disposed to receive modulated light reflected from said reflective light modulator.
Claim 33
Dependent Claim
17 words
The image projector of claim 25, wherein said polarizer and said analyzer are separate from one another.
Claim 34
Dependent Claim
16 words
The image projector of claim 26, wherein said polarizer and said analyzer each comprise linear polarizers.
References Cited (Backward Citations)
US4739396C1
Cited
US4739396A
Cited
US5075798A
Cited
US4935656A
Cited
US4796978A
Cited
US4864390A
Cited
US4864390B1
Cited
US4989076A
Cited
US5012274A
Cited
US5097323A
Cited
US5105265A
Cited
US4962997A
Cited
US5098183A
Cited
US5386306A
Cited
US5042929A
Cited
US5060058A
Cited
US5108172A
Cited
US5024524A
Cited
US5022750A
Cited
US5245449A
Cited
US5231431A
Cited
US5239322A
Cited
US5115305A
Cited
US5181054A
Cited
US5321448A
Cited
US5400180A
Cited
US5390048A
Cited
US5459539A
Cited
US5420655A
Cited
US5486881A
Cited
US5467146A
Cited
US5815221A
Cited
US5798819A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-04-04 | 2003-10-04 | 2004-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-04-04 | 2007-10-04 | 2008-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-04-04 | 2011-10-04 | 2012-04-04 | $7700.00 | Window Closed / Lapsed |