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US6461001B2 Expired / Lapsed US ⏱️ 0.0 years remaining

Illumination apparatus and projection type display apparatus

Assignee: Rakuten Group Inc
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Filing: 2001-04-23
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Granted: 2002-10-08
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Expires: 2021-04-23
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Abstract

Abstract An illumination apparatus and a projection type display apparatus of lower cost are provided, in which extra-axial aberrations, especially distortion and lateral aberration, are favorably corrected, and the dimensional margin of illumination is suppressed to enhance the utilization factor of light. The illumination apparatus includes a first group of lenses which includes a meniscus lens having a positive refracting power, a second group of lenses which includes first lens means having a negative refracting power and second lens means having a positive refracting power, and lens means whose surface immediately before a surface to-be-illuminated is a plane surface, whereby an illuminating light beam is caused to exit in a telecentric state.

Inventors

  • 👤 Shinji Okamori
  • 👤 Akihisa Miyata
  • 👤 Takeshi Utakoji
  • 👤 Shinsuke Shikama

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 14:14
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/005

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 250 words
An illumination apparatus comprising: focusing means for focusing light emitted from a light source; columnar optical means having its light entrance portion located in the vicinity of a position where the emitted light is focused by said focusing means, and for propagating the entering light having entered from the light entrance portion and causing the propagated light to exit from its light exit portion; and transferring optical means including a first group of lenses which receive the exiting light from said columnar optical means and which have a positive refracting power, a second group of lenses which receive exiting light from the first group of lenses and which have a positive refracting power, and a third group of lenses which receive exiting light from the second group of lenses and which have a positive refracting power, wherein the respective groups of lenses are successively arrayed from a side of said columnar optical means toward a side of a surface to-be-illuminated and satisfy relationships of inequalities (1) and (2) given below, and wherein the light exit portion of said columnar optical means and the surface to-be-illuminated are held in a conjugate relationship; 0.37 <f 1/ f 0<0.62  (1) υ p/υn> 1.99  (2) where f0: focal length of said transferring optical means, f1: focal length of said first group of lenses, υp: means Abbe number of a positive lens included in said second group of lenses, and υn: means Abbe number of a negative lens included in said second group of lenses.
Claim 2
Dependent Claim 250 words
An illumination apparatus comprising: focusing means for focusing light emitted from a light source; columnar optical means having its light entrance portion located in the vicinity of a position where the emitted light is focused by said focusing means, and for propagating the entering light having entered from the light entrance portion and causing the propagated light to exit from its light exit portion; and transferring optical means including a first group of lenses which receive the exiting light from said columnar optical means and which have a positive refracting power, a second group of lenses which receive exiting light from the first group of lenses and which have a positive refracting power, and a third group of lenses which receive exiting light from the second group of lenses and which have a positive refracting power, wherein the respective groups of lenses are successively arrayed from a side of said columnar optical means toward a side of a surface to-be-illuminated and satisfy relationships of inequalities (1) and (2) given below, and wherein the light exit portion of said columnar optical means and the surface to-be-illuminated are held in a conjugate relationship; 0.37 <f 1/ f 0<0.62  (1) υ p/υn> 1.99  (2) where f0: focal length of said transferring optical means, f1: focal length of said first group of lenses, υp: means Abbe number of a positive lens included in said second group of lenses, and υn: means Abbe number of a negative lens included in said second group of lenses.
Claim 3
Dependent Claim 63 words
An illumination apparatus as defined in claim 1 , wherein said second group of lenses include a meniscus lens which is convex to the side of said columnar optical means and which has a negative refracting power, and a biconvex lens, and the respective lenses are successively arrayed from said side of said columnar optical means toward the side of the surface to-be-illuminated.
Claim 4
Dependent Claim 68 words
An illumination apparatus as defined in claim 2 , wherein among the lenses constituting the first to third groups of lenses, the meniscus lens having the negative refracting power and included in said second group of lenses is made of a glass material which is different from a glass material of any other lens, and the glass materials of all the other lenses are of the same kind.
Claim 5
Dependent Claim 26 words
An illumination apparatus as defined in claim 1 , further comprising optical-path deflection means between said second group of lenses and said third group of lenses.
Claim 6
Dependent Claim 26 words
An illumination apparatus as defined in claim 2 , further comprising optical-path deflection means between said second group of lenses and said third group of lenses.
Claim 7
Dependent Claim 26 words
An illumination apparatus as defined in claim 3 , further comprising optical-path deflection means between said second group of lenses and said third group of lenses.
Claim 8
Dependent Claim 27 words
An illumination apparatus as defined in claim 1 , wherein said columnar optical means has a hollow structure, an inner surface of which is a reflective surface.
Claim 9
Dependent Claim 340 words
A projection type display apparatus comprising: a light source; focusing means for focusing light emitted from said light source; columnar optical means having its light entrance portion located in the vicinity of a position where the emitted light is focused by said focusing means, and for propagating the entering light having entered from the light entrance portion and causing the propagated light to exit from its light exit portion; transferring optical means including a first group of lenses which receive the exiting light from said columnar optical means and which have a positive refracting power, a second group of lenses which receive exiting light from the first group of lenses and which have a positive refracting power, and a third group of lenses which receive exiting light from the second group of lenses and which have a positive refracting power, wherein the respective groups of lenses are successively arrayed from a side of said columnar optical means toward a side of a surface to-be-illuminated and satisfy relationships of inequalities (1) and (2) given below, and wherein the light exit portion of said columnar optical means and the surface to-be-illuminated are held in a conjugate relationship; optical-path deflection means receiving light exiting from said transferring optical means, and for deflecting the exiting light in a direction different from an entering direction thereof; light modulation means disposed at a position of the surface to-be-irradiated so as to receive the exiting light from said transferring optical means after the deflection by said optical-path deflection means, and for modulating said exiting light in two dimensions so as to generate modulated light; and projection means for projecting the modulated light generated by said light modulation means; 0.37 <f 1/ f 0<0.62  (1) υ p/υn> 1.99  (2) where f0: focal length of said transferring optical means, f1: focal length of said first group of lenses, υp: means Abbe number of a positive lens included in said second group of lenses, and υn: means Abbe number of a negative lens included in said second group of lenses.
Claim 10
Dependent Claim 340 words
A projection type display apparatus comprising: a light source; focusing means for focusing light emitted from said light source; columnar optical means having its light entrance portion located in the vicinity of a position where the emitted light is focused by said focusing means, and for propagating the entering light having entered from the light entrance portion and causing the propagated light to exit from its light exit portion; transferring optical means including a first group of lenses which receive the exiting light from said columnar optical means and which have a positive refracting power, a second group of lenses which receive exiting light from the first group of lenses and which have a positive refracting power, and a third group of lenses which receive exiting light from the second group of lenses and which have a positive refracting power, wherein the respective groups of lenses are successively arrayed from a side of said columnar optical means toward a side of a surface to-be-illuminated and satisfy relationships of inequalities (1) and (2) given below, and wherein the light exit portion of said columnar optical means and the surface to-be-illuminated are held in a conjugate relationship; optical-path deflection means receiving light exiting from said transferring optical means, and for deflecting the exiting light in a direction different from an entering direction thereof; light modulation means disposed at a position of the surface to-be-irradiated so as to receive the exiting light from said transferring optical means after the deflection by said optical-path deflection means, and for modulating said exiting light in two dimensions so as to generate modulated light; and projection means for projecting the modulated light generated by said light modulation means; 0.37 <f 1/ f 0<0.62  (1) υ p/υn> 1.99  (2) where f0: focal length of said transferring optical means, f1: focal length of said first group of lenses, υp: means Abbe number of a positive lens included in said second group of lenses, and υn: means Abbe number of a negative lens included in said second group of lenses.
Claim 11
Dependent Claim 28 words
A projection type display apparatus as defined in claim 8 , further comprising optical-path deflection means between said second group of lenses and the third group of lenses.
Claim 12
Dependent Claim 37 words
A projection type display apparatus as defined in claim 8 , wherein a color filter is disposed in the vicinity of either of the light entrance portion and the light exit portion of said columnar optical means.

References Cited (Backward Citations)

GB324166A Cited
US5795047A Cited
JPH10161237A Cited
JPH112780A Cited
US5860721A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2005-10-07 2006-04-08 2006-10-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2009-10-07 2010-04-08 2010-10-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2013-10-07 2014-04-08 2014-10-08 $7700.00 Window Closed / Lapsed

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