Patent US6243152B1 successfully refreshed from Google Patents.
US6243152B1
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Contrast polymer dispersed liquid crystal projection display system
Assignee: Duke University
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Filing: 1996-12-17
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Granted: 2001-06-05
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Expires: 2016-12-17
Abstract
Abstract A polymer dispersed liquid crystal projection display is provided that has enhanced contrast. In the projection system using a polymer dispersed liquid crystal display (PDLC), polarized light is used as the light source onto the PDLC. The reflected light maintains its polarization, while the scattered light from the off pixels of the PDLC randomize the polarization. The polarized image is then passed through a polarizing filter which eliminates half of the scattered light, whereas practically all of the polarized image is passed onto the display source. In this way, the contrast between the on and off pixels is effectively doubled.
Inventors
- 👤 Richard M. Knox
- 👤 Mehdi Zeinali
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:22
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3141; H04N9/315; H04N9/3167; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1334; H04N5/00; H04N5/74; H04N5/7416; H04N5/7441
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
134 words
A projection display engine comprising: a light source; a filter adapted to selectively direct light derived from the light source as polarized light, the polarized light comprising one of certain polarization and certain other polarization; a polymer dispersed liquid crystal display adapted to receive one of the certain polarization and the certain other polarization and to return a polarized image in one of the certain polarization and the certain other polarization, the polarized image being directed as an image to be displayed, some light scattered by the polymer dispersed liquid crystal being blocked from being in the image to be displayed; and a polarization specific reflector disposed in a path of the polarized image and adapted to direct the certain polarization along a first direction and the certain other polarization along a second direction.
Claim 2
Dependent Claim
134 words
A projection display engine comprising: a light source; a filter adapted to selectively direct light derived from the light source as polarized light, the polarized light comprising one of certain polarization and certain other polarization; a polymer dispersed liquid crystal display adapted to receive one of the certain polarization and the certain other polarization and to return a polarized image in one of the certain polarization and the certain other polarization, the polarized image being directed as an image to be displayed, some light scattered by the polymer dispersed liquid crystal being blocked from being in the image to be displayed; and a polarization specific reflector disposed in a path of the polarized image and adapted to direct the certain polarization along a first direction and the certain other polarization along a second direction.
Claim 3
Dependent Claim
22 words
The projection display engine of claim 1 , wherein the polarization specific reflector is adapted to provide the polarized light for imaging.
Claim 4
Dependent Claim
45 words
The projection display engine of claim 1 , wherein the light source comprises a lamp, and wherein the polarization specific reflector is disposed between the lamp and the polymer dispersed liquid crystal display, the polarization specific reflector adapted to direct the polarized light for imaging.
Claim 5
Dependent Claim
17 words
The projection display engine of claim 1 , wherein the filter comprises a polarization specific reflecting polarizer.
Claim 6
Dependent Claim
43 words
The projection display engine of claim 1 , wherein the light source further comprises a lamp adapted to provide the light derived from the light source, wherein the light derived from the light source is divided into the polarized light and other light.
Claim 7
Dependent Claim
34 words
The projection display engine of claim 1 , further comprising a retarder disposed between the light source and the polymer dispersed liquid crystal display, the retarder adapted to rotate polarization of the polarized image.
Claim 8
Dependent Claim
34 words
The projection display engine of claim 1 , wherein the polarization specific reflector transmits the polarized light to the polymer dispersed liquid crystal display, and wherein the polarization specific reflector reflects the polarized image.
Claim 9
Dependent Claim
18 words
The projection display engine of claim 1 , wherein the polarization specific reflector enhances contrast of the image.
Claim 10
Dependent Claim
14 words
The projection display engine of claim 1 , wherein the filter comprises a polarizer.
Claim 11
Dependent Claim
161 words
A projection system comprising: a light source; a filter adapted to selectively direct light derived from the light source as polarized light, the polarized light comprising one of certain polarization and certain other polarization; a polymer dispersed liquid crystal display adapted to receive one of the certain polarization and the certain other polarization and to return a polarized image in one of the certain polarization and the certain other polarization, the polarized image being directed as an image to be displayed, some light scattered by the polymer dispersed liquid crystal being blocked from being in the image to be displayed; a polarization specific reflector disposed in a path of the polarized image and adapted to direct the certain polarization along a first direction and the certain other polarization along a second direction; a controller adapted to receive video data, the controller coupled to the polymer dispersed liquid crystal display to provide the image; and a display screen for receiving the image.
Claim 12
Dependent Claim
161 words
A projection system comprising: a light source; a filter adapted to selectively direct light derived from the light source as polarized light, the polarized light comprising one of certain polarization and certain other polarization; a polymer dispersed liquid crystal display adapted to receive one of the certain polarization and the certain other polarization and to return a polarized image in one of the certain polarization and the certain other polarization, the polarized image being directed as an image to be displayed, some light scattered by the polymer dispersed liquid crystal being blocked from being in the image to be displayed; a polarization specific reflector disposed in a path of the polarized image and adapted to direct the certain polarization along a first direction and the certain other polarization along a second direction; a controller adapted to receive video data, the controller coupled to the polymer dispersed liquid crystal display to provide the image; and a display screen for receiving the image.
Claim 13
Dependent Claim
14 words
The projection system of claim 10 , wherein the light source comprises a lamp.
Claim 14
Dependent Claim
24 words
The projection system of claim 11 , wherein the polarization specific reflector is disposed between the lamp and the polymer dispersed liquid crystal display.
Claim 15
Independent Claim
127 words
A method of enhancing the contrast in a display system, the method comprising: selectively directing light derived from a light source as polarized light in one of certain polarization and certain other polarization; directing the polarized light to a polymer dispersed liquid crystal display, the polymer dispersed liquid crystal display receiving one of the certain polarization and the certain other polarization; returning a polarized image in one of the certain polarization and the certain other polarization from the polymer dispersed liquid crystal display, some light scattered by the polymer dispersed liquid crystal blocked from being in the polarized image; and passing the polarized image to a polarization specific reflector for directing the certain polarization along a first direction and the certain other polarization along a second direction.
Claim 16
Independent Claim
127 words
A method of enhancing the contrast in a display system, the method comprising: selectively directing light derived from a light source as polarized light in one of certain polarization and certain other polarization; directing the polarized light to a polymer dispersed liquid crystal display, the polymer dispersed liquid crystal display receiving one of the certain polarization and the certain other polarization; returning a polarized image in one of the certain polarization and the certain other polarization from the polymer dispersed liquid crystal display, some light scattered by the polymer dispersed liquid crystal blocked from being in the polarized image; and passing the polarized image to a polarization specific reflector for directing the certain polarization along a first direction and the certain other polarization along a second direction.
Claim 17
Dependent Claim
16 words
The method of claim 13 , further comprising directing the polarized image to a projection surface.
Claim 18
Dependent Claim
36 words
The method of claim 13 , further comprising providing a lamp for providing the light derived from the light source and disposing the polarization specific reflector between the lamp and the polymer dispersed liquid crystal display.
Claim 19
Dependent Claim
108 words
A projection display engine comprising: a light source; a polarization specific reflector adapted to reflect certain polarization of light derived from the light source; a polymer dispersed liquid crystal display adapted to receive a portion of the light derived from the light source and to return a polarized image, all the light for imaging by the polymer dispersed liquid crystal display having the same relative polarization from the polarization specific reflector to the polymer dispersed liquid crystal display; and a filter adapted to selectively direct polarized light from the light derived from the light source, wherein some light scattered by the polymer dispersed liquid crystal display is blocked.
Claim 20
Dependent Claim
108 words
A projection display engine comprising: a light source; a polarization specific reflector adapted to reflect certain polarization of light derived from the light source; a polymer dispersed liquid crystal display adapted to receive a portion of the light derived from the light source and to return a polarized image, all the light for imaging by the polymer dispersed liquid crystal display having the same relative polarization from the polarization specific reflector to the polymer dispersed liquid crystal display; and a filter adapted to selectively direct polarized light from the light derived from the light source, wherein some light scattered by the polymer dispersed liquid crystal display is blocked.
Claim 21
Dependent Claim
17 words
The projection display engine of claim 16 , wherein the polarization specific reflector comprises a reflecting polarizer.
Claim 22
Dependent Claim
42 words
The projection display engine of claim 16 , wherein the light source comprises a lamp adapted to provide the light derived from the light source, wherein the light derived from the light source is divided into the polarized light and other light.
Claim 23
Dependent Claim
24 words
The projection display engine of claim 16 , wherein the polarization specific reflector directs the polarized light to the polymer dispersed liquid crystal display.
Claim 24
Dependent Claim
24 words
The projection display engine of claim 16 , wherein the polarization specific reflector transmits the polarized light to the polymer dispersed liquid crystal display.
Claim 25
Dependent Claim
34 words
The projection display engine of claim 16 , further comprising a retarder disposed between the light source and the polymer dispersed liquid crystal display, the retarder adapted to rotate polarization of the polarized image.
Claim 26
Dependent Claim
34 words
The projection display engine of claim 16 , wherein the polarization specific reflector transmits the polarized light to the polymer dispersed liquid crystal display, and wherein the polarization specific reflector reflects the polarized image.
Claim 27
Dependent Claim
15 words
The projection display engine of claim 16 , wherein the filter comprises a reflecting polarizer.
Claim 28
Dependent Claim
14 words
The projection display engine of claim 16 , wherein the filter comprises a polarizer.
Claim 29
Independent Claim
97 words
A method of enhancing contrast in a display system, the method comprising: providing polarized light from a light source having a polarization specific reflector that reflects certain polarization; directing the polarized light to a polymer dispersed liquid crystal display; reflecting, in a single pass by the polarization specific reflector, all the polarized light for imaging by the polymer dispersed liquid crystal display; returning a polarized image from the polymer dispersed liquid crystal display; and passing the polarized light through a polarization selective filter to filter out light polarizations other than the polarization meant for the polarized image.
Claim 30
Independent Claim
97 words
A method of enhancing contrast in a display system, the method comprising: providing polarized light from a light source having a polarization specific reflector that reflects certain polarization; directing the polarized light to a polymer dispersed liquid crystal display; reflecting, in a single pass by the polarization specific reflector, all the polarized light for imaging by the polymer dispersed liquid crystal display; returning a polarized image from the polymer dispersed liquid crystal display; and passing the polarized light through a polarization selective filter to filter out light polarizations other than the polarization meant for the polarized image.
Claim 31
Dependent Claim
16 words
The method of claim 25 , further comprising directing the polarized image to a projection surface.
Claim 32
Dependent Claim
18 words
The method of claim 25 , wherein the reflecting comprises reflecting before the polymer dispersed liquid crystal display.
Claim 33
Dependent Claim
18 words
The method of claim 25 , wherein the reflecting comprises reflecting after the polymer dispersed liquid crystal display.
Claim 34
Dependent Claim
18 words
The method of claim 25 , wherein the passing comprises passing before the polymer dispersed liquid crystal display.
Claim 35
Dependent Claim
18 words
The method of claim 25 , wherein the passing comprises passing after the polymer dispersed liquid crystal display.
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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) | 2004-06-04 | 2004-12-04 | 2005-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-06-04 | 2008-12-04 | 2009-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-06-04 | 2012-12-04 | 2013-06-05 | $7700.00 | Window Closed / Lapsed |