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US5073013A
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Projection-type display device
Assignee: Seiko Epson Corp
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Filing: 1989-10-19
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Granted: 1991-12-17
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Expires: 2009-10-19
Abstract
Abstract A projection-type display device having a single light source which produces light. A first dichroic mirror group receives the light and separates it into colored light. A transmissive light valve system modulates the colored light and a second dichoric mirror group synthesizes the modulated colored light. A projection system projects the synthesized colored light onto a screen.
Inventors
- 👤 Tomio Sonehara
- 👤 Shuji Aruga
- 👤 Shinji Morozumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:46
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/10; G02B27/1006; G02B27/102; G02B27/1046; G02B27/14; G02B27/145; G02B27/149; H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3105; H04N9/3141; H04N9/315; H04N9/3167
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
187 words
A projection-type display device comprising a light source for producing light, color segregating means for receiving said light and segregating said light into at least two different colored lights, color modulating means having at least two light valves each of which receives one of said colored lights, modulates said colored lights and generates color images in response thereto, color synthesizing means including at least two dichroic optical elements for synthesizing said color images, and projection means for projecting said synthesized image, each modulated colored light having a polarization axis, said light incident to and said light outputted from said color synthesizing means each having an optical axis, said polarization axes of said modulated color lights being substantially perpendicular to a plane formed by the optical axis of the light incident to said color synthesizing means and the optical axis of the light outputted from said color synthesizing means when said colored lights are reflected at least once at said dichroic optical elements, the polarization axes of said modulated color lights being substantially parallel to said plane when said colored lights are transmitted through said dichroic optical elements.
Claim 2
Dependent Claim
187 words
A projection-type display device comprising a light source for producing light, color segregating means for receiving said light and segregating said light into at least two different colored lights, color modulating means having at least two light valves each of which receives one of said colored lights, modulates said colored lights and generates color images in response thereto, color synthesizing means including at least two dichroic optical elements for synthesizing said color images, and projection means for projecting said synthesized image, each modulated colored light having a polarization axis, said light incident to and said light outputted from said color synthesizing means each having an optical axis, said polarization axes of said modulated color lights being substantially perpendicular to a plane formed by the optical axis of the light incident to said color synthesizing means and the optical axis of the light outputted from said color synthesizing means when said colored lights are reflected at least once at said dichroic optical elements, the polarization axes of said modulated color lights being substantially parallel to said plane when said colored lights are transmitted through said dichroic optical elements.
Claim 3
Dependent Claim
85 words
The projection-type display device as claimed in claim 1, wherein said color modulating means includes first, second and third liquid crystal light valves each having a polarizer means, the polarization axes of the polarizer means being adjusted so that the colored lights modulated by said first and second light valves are polarized lights having polarization axes which are perpendicular to said plane, the colored light modulated by said third light valve being a polarized light having a polarization axis which is parallel to said plane.
Claim 4
Dependent Claim
55 words
The projection-type display device as claimed in claim 2, wherein said color segregating means segregates red, blue and green colored lights, said first liquid crystal light valve modulating said red colored light, said second liquid crystal light valve modulating said blue colored light and said third liquid crystal light valve modulating said green colored light.
Claim 5
Dependent Claim
34 words
The projection-type display device as claimed in claim 2, wherein the white balance defined by the intensity of each color is selected by adjusting the direction of the polarizers associated with each light valve.
Claim 6
Dependent Claim
30 words
The projection-type display device as in claim 1, wherein each of said at least two dichroic optical elements synthesize at least two different colored lights into a single light beam.
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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) | 1994-12-16 | 1995-06-17 | 1995-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-16 | 1999-06-17 | 1999-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-16 | 2003-06-17 | 2003-12-17 | $7700.00 | Window Closed / Lapsed |