← Back to Patent Explorer
US6781640B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Projection display having polarization compensator

Assignee: Sharp Laboratories of America Inc
•
Filing: 1999-11-15
•
Granted: 2004-08-24
•
Expires: 2019-11-15
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A projection display system includes a light source, at least-one polarizer, at least one liquid crystal panel for generating an image, and a projection lens for projecting the image. The system includes a polarization compensator having a plurality of regions each having a respective birefringence. The birefringence of one of the regions is different than the birefringence of another of the regions. The birefringence of the various regions may be controlled electrically.

Inventors

  • 👤 Austin L. Huang

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 19:25
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3105; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/13363; G02F1/133631; G02F1/1347; G02F2203/00; G02F2203/62

Claims Analysis

Total Claims: 35
Claim 1
Independent Claim 172 words
A projection display system, comprising: (a) a light source; (b) at least one polarizer for polarizing light from said light source; (c) at least one liquid crystal panel for generating an image, and which together with said polarizer, acts to polarize light from said light source generally into a uniaxial orientation; (d) a projection source for projecting said image; (e) a polarization compensator having a plurality of light transmitting regions each having an incident face for receiving incident light and each having a respective birefringence, where said birefringence of each respective region is based on the variance of the polarization of said incident light on the incident face of said respective region from said uniaxial orientation, where said birefringence reduces said variance, and where said birefringence of at least one of said regions is different than said birefringence of another of said regions; (f) wherein said polarization compensator is located substantially coincident with where the angular distribution of the light is directly related to its physical location within said projection display system.
Claim 2
Dependent Claim 172 words
A projection display system, comprising: (a) a light source; (b) at least one polarizer for polarizing light from said light source; (c) at least one liquid crystal panel for generating an image, and which together with said polarizer, acts to polarize light from said light source generally into a uniaxial orientation; (d) a projection source for projecting said image; (e) a polarization compensator having a plurality of light transmitting regions each having an incident face for receiving incident light and each having a respective birefringence, where said birefringence of each respective region is based on the variance of the polarization of said incident light on the incident face of said respective region from said uniaxial orientation, where said birefringence reduces said variance, and where said birefringence of at least one of said regions is different than said birefringence of another of said regions; (f) wherein said polarization compensator is located substantially coincident with where the angular distribution of the light is directly related to its physical location within said projection display system.
Claim 3
Dependent Claim 15 words
The projection display of claim 1 wherein said regions are arranged in a rectangular matrix.
Claim 4
Dependent Claim 12 words
The projection display of claim 1 wherein said regions are arranged concentrically.
Claim 5
Dependent Claim 11 words
The projection display of claim 1 having more than two regions.
Claim 6
Dependent Claim 16 words
The projection display of claim 1 wherein said polarization compensator is a transmissive liquid crystal device.
Claim 7
Dependent Claim 29 words
The projection display of claim 5 wherein at least one of said regions has a director orientation that is different than another director orientation of another of said regions.
Claim 8
Dependent Claim 23 words
The projection display of claim 1 , further comprising an analyzer, and said polarization compensator is located between said polarizer and said analyzer.
Claim 9
Dependent Claim 20 words
The projection display of claim 1 wherein said polarization compensator is located at an aperture stop of said projection display.
Claim 10
Dependent Claim 17 words
The projection display of claim 1 wherein said polarization compensator is built into said liquid crystal panel.
Claim 11
Dependent Claim 22 words
The projection display of claim 1 wherein said polarization compensator is located at one of an entrance pupil and an exit pupil.
Claim 12
Dependent Claim 18 words
The projection display of claim 1 wherein said polarization compensator is located adjacent to said liquid crystal panel.
Claim 13
Dependent Claim 15 words
The projection display of claim 1 wherein each of said regions has electrically controlled birefringence.
Claim 14
Dependent Claim 19 words
The projection display of claim 12 , further comprising a feedback mechanism to adjust said birefringence of said regions.
Claim 15
Dependent Claim 16 words
The projection display of claim 12 wherein said birefringence of said regions is adjustable over time.
Claim 16
Dependent Claim 16 words
The projection display of claim 1 wherein said birefringence of each of said regions is fixed.
Claim 17
Dependent Claim 15 words
The projection display of claim 1 , further comprising a plurality of liquid crystal panels.
Claim 18
Independent Claim 121 words
A method for displaying an image, comprising: (a) providing light generally polarized in a uniaxial orientation; (b) generating an image from said polarized light; (c) determining a variance, from said uniaxial orientation, of the polarization of light at a first location and a second location of said image, each of said locations being located in a plane that is substantially perpendicular to said light; (d) reducing said variance at said first and second locations where said reduction at said first location is different than said reduction at said second location; (e) projecting said image; (f) wherein said variance is said reduced at a location substantially coincident with where the angular distribution of the light is directly related to its physical location.
Claim 19
Independent Claim 121 words
A method for displaying an image, comprising: (a) providing light generally polarized in a uniaxial orientation; (b) generating an image from said polarized light; (c) determining a variance, from said uniaxial orientation, of the polarization of light at a first location and a second location of said image, each of said locations being located in a plane that is substantially perpendicular to said light; (d) reducing said variance at said first and second locations where said reduction at said first location is different than said reduction at said second location; (e) projecting said image; (f) wherein said variance is said reduced at a location substantially coincident with where the angular distribution of the light is directly related to its physical location.
Claim 20
Dependent Claim 11 words
The method of claim 17 wherein said locations correspond to pixels.
Claim 21
Dependent Claim 14 words
The method of claim 18 wherein said pixels are arranged in a rectangular matrix.
Claim 22
Dependent Claim 11 words
The method of claim 18 wherein said pixels are arranged concentrically.
Claim 23
Dependent Claim 16 words
The method of claim 17 wherein said polarization defects are corrected at more than two locations.
Claim 24
Dependent Claim 17 words
The method of claim 17 wherein said polarization defects are corrected using a transmissive liquid crystal device.
Claim 25
Dependent Claim 30 words
The method of claim 22 wherein said transmissive liquid crystal device has at least one pixel having a director orientation that is different than another director orientation of another pixel.
Claim 26
Dependent Claim 28 words
The method of claim 17 , further comprising transmitting said light through an analyzer, and said polarization defects are corrected before said light is transmitted through said analyzer.
Claim 27
Dependent Claim 15 words
The method of claim 17 wherein said polarization defects are corrected at an aperture stop.
Claim 28
Dependent Claim 16 words
The method of claim 17 wherein said polarization defects are corrected at a liquid crystal panel.
Claim 29
Dependent Claim 21 words
The method of claim 17 wherein said polarization defects are corrected at one of an entrance pupil and an exit pupil.
Claim 30
Dependent Claim 20 words
The method of claim 17 wherein said polarization defects are corrected at a location adjacent to a liquid crystal panel.
Claim 31
Dependent Claim 44 words
The method of claim 17 wherein said polarization defects are corrected by providing a polarization compensator having a plurality of pixels each having a respective birefringence, said birefringence of one of said pixels being is different than said birefringence of another of said pixels.
Claim 32
Dependent Claim 15 words
The method of claim 29 , further comprising electronically controlling said birefringence of said pixels.
Claim 33
Dependent Claim 26 words
The method of claim 17 further comprising the step of feeding back an output signal representative of said light in order to correct said polarization defects.
Claim 34
Dependent Claim 14 words
The method of claim 17 wherein said polarization defects are corrected at different times.
Claim 35
Dependent Claim 15 words
The method of claim 17 wherein the birefringence of each of said locations is fixed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2007-08-24 2008-02-23 2008-08-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2011-08-24 2012-02-23 2012-08-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2015-08-24 2016-02-23 2016-08-24 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag