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US5278595A Expired / Lapsed US ⏱️ 0.0 years remaining

Liquid crystal type rear-projection television with a reduced cabinet depth

Assignee: Pioneer Corp
•
Filing: 1992-10-06
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Granted: 1994-01-11
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Expires: 2012-10-06
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Abstract

Abstract A liquid crystal projector is obliquely disposed in a lower front portion of a cabinet. A first mirror for reflecting light beams of R, G and B coming from the liquid crystal projector is disposed obliquely with respect to the top-bottom, right-left and front-rear directions of the cabinet. A second mirror is disposed so as to be inclined toward a screen. With this configuration, the optical axis of the light beams that extends from the liquid crystal projector to the screen is folded back three-dimensionally. In the liquid crystal projector, the optical axis of a condensing reflector may be slightly inclined from the central axis of a projection lens.

Inventors

  • 👤 Masami Nishida
  • 👤 Masataka Izawa
  • 👤 Tadashi Yoshida

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 22:13
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3105

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 173 words
A liquid crystal type rear-projection television comprising: a liquid crystal projector including light source means, liquid crystal panels for red, green and blue and a projection lens, for producing light beams of red, green and blue that carry a color image by passing while light provided by the light source means through the liquid crystal panels, and for outputting the light beams through the projection lens; at least two mirrors for sequentially reflecting the light beams coming from the liquid crystal projector; and a screen for receiving, at its rear surface, the light beams reflected from a last one of the at least two mirrors to display the color image at its front surface; wherein the liquid crystal projector and the at least two mirrors are arranged so that an optical axis of the light beams extending from the liquid crystal projector to the screen is folded back three-dimensionally; and wherein at least one of the at least two mirrors is arranged obliquely with respect to all of top-bottom, right-left and front-rear directions.
Claim 2
Dependent Claim 173 words
A liquid crystal type rear-projection television comprising: a liquid crystal projector including light source means, liquid crystal panels for red, green and blue and a projection lens, for producing light beams of red, green and blue that carry a color image by passing while light provided by the light source means through the liquid crystal panels, and for outputting the light beams through the projection lens; at least two mirrors for sequentially reflecting the light beams coming from the liquid crystal projector; and a screen for receiving, at its rear surface, the light beams reflected from a last one of the at least two mirrors to display the color image at its front surface; wherein the liquid crystal projector and the at least two mirrors are arranged so that an optical axis of the light beams extending from the liquid crystal projector to the screen is folded back three-dimensionally; and wherein at least one of the at least two mirrors is arranged obliquely with respect to all of top-bottom, right-left and front-rear directions.
Claim 3
Dependent Claim 31 words
The liquid crystal type rear-projection television of claim 1, wherein the liquid crystal projector is disposed so as to deviate from a center of the rear-projection television in the right-left direction.
Claim 4
Dependent Claim 25 words
The liquid crystal type rear-projection television of claim 1, wherein at least one of the at least two mirrors has an irregular tetragon reflection plane.
Claim 5
Dependent Claim 33 words
The liquid crystal type rear-projection television of claim 1, wherein an optical axis of the light source means is inclined from a central axis of the projection lens of the liquid crystal projector.
Claim 6
Dependent Claim 75 words
The liquid crystal type rear=projection television of claim 4, wherein the liquid crystal projector further includes a first three-color separating/combining prism device for separating the white light provided from the light source means into three light beams to be input to the respective liquid crystal panels, and a second three-color separating/combining prism device for combining the light beams provided from the respective liquid crystal panels to form a single light beam carrying the color image.
Claim 7
Dependent Claim 220 words
A liquid crystal type rear-projection television comprising: a liquid crystal projector including light source means, liquid crystal panels for red, green and blue and a projection lens, for producing light beams of red, green and blue that carry a color image by passing white light provided by the light source means through the liquid crystal panels, and for outputting the light beams through the projection lens; at least two mirrors for sequentially reflecting the light beams coming from the liquid crystal projector; and a screen for receiving, at its rear surface, the light beams reflected from a last one of the at least two mirrors to display the color image at its front surface; wherein the liquid crystal projector and the at least two mirrors are arranged so that an optical axis of the light beams extending from the liquid crystal projector to the screen is folded back three-dimensionally; and wherein the at least two mirrors consist of first and second mirrors, and wherein the optical axis of the light beams is expressed as: Nm.sub.2 =aNm.sub.1 +bY where a and b are constants, Nm 1 is a vector along a normal of the first mirror, Nm 2 is a vector along a normal of the second mirror, and Y is a vector along a shorter axis of the second mirror.
Claim 8
Dependent Claim 220 words
A liquid crystal type rear-projection television comprising: a liquid crystal projector including light source means, liquid crystal panels for red, green and blue and a projection lens, for producing light beams of red, green and blue that carry a color image by passing white light provided by the light source means through the liquid crystal panels, and for outputting the light beams through the projection lens; at least two mirrors for sequentially reflecting the light beams coming from the liquid crystal projector; and a screen for receiving, at its rear surface, the light beams reflected from a last one of the at least two mirrors to display the color image at its front surface; wherein the liquid crystal projector and the at least two mirrors are arranged so that an optical axis of the light beams extending from the liquid crystal projector to the screen is folded back three-dimensionally; and wherein the at least two mirrors consist of first and second mirrors, and wherein the optical axis of the light beams is expressed as: Nm.sub.2 =aNm.sub.1 +bY where a and b are constants, Nm 1 is a vector along a normal of the first mirror, Nm 2 is a vector along a normal of the second mirror, and Y is a vector along a shorter axis of the second mirror.
Claim 9
Independent Claim 149 words
A method of displaying a color image in a liquid crystal type rear-projection television, comprising the steps of: arranging a liquid crystal projector, at least two mirrors and a screen so that an optical axis of a light beam extending from the liquid crystal projector to the screen via the at least two mirrors is folded back three-dimensionally and that at least one of the at least two mirrors is arranged obliquely with respect to all of top-bottom, right-left, and front-rear directions; producing light beams of red, green and blue that carry a color image by the liquid crystal projector; sequentially reflecting the light beams coming from the liquid crystal projector by the at least two mirrors; and projecting the light beams reflected from a last one of the at least two mirrors to a rear surface of the screen to display the color image at its front surface.
Claim 10
Independent Claim 149 words
A method of displaying a color image in a liquid crystal type rear-projection television, comprising the steps of: arranging a liquid crystal projector, at least two mirrors and a screen so that an optical axis of a light beam extending from the liquid crystal projector to the screen via the at least two mirrors is folded back three-dimensionally and that at least one of the at least two mirrors is arranged obliquely with respect to all of top-bottom, right-left, and front-rear directions; producing light beams of red, green and blue that carry a color image by the liquid crystal projector; sequentially reflecting the light beams coming from the liquid crystal projector by the at least two mirrors; and projecting the light beams reflected from a last one of the at least two mirrors to a rear surface of the screen to display the color image at its front surface.

References Cited (Backward Citations)

US3947104A Cited
US4875064A Cited
US4941732A Cited
US5097323A Cited
US4961642A Cited
US5096288A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-01-10 1997-07-12 1998-01-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-01-10 2001-07-12 2002-01-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-01-10 2005-07-12 2006-01-11 $7700.00 Window Closed / Lapsed

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