US5384659A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Condenser lens, polarizing element, light source apparatus, and projection display apparatus
Assignee: Mitsubishi Electric Corp
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Filing: 1993-04-16
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Granted: 1995-01-24
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Expires: 2013-04-16
Abstract
Abstract Disclosed is a condenser lens with large aperture, having a numerical aperture of 0.9 or larger, which consists of a bi-aspherical single lens having a first surface of convex form facing the larger conjugate side and a second surface facing the smaller conjugate side and whose outermost circular zone is formed concave, the condenser lens satisfying the following conditions (1) or (2). Also disclosed are a light source apparatus using such a condenser lens and a projection display apparatus using such a light source apparatus. (1) 0.42<r1/nf<0.45 18<|r2/nf|-0.39<K1<-0.25 0.11< DELTA 2/f<0.14 (2) 0.4<r1/nf<0.6 -0.5<r2/nf<-0.3 -0.6<K1<-0.2 -0.1<SG2/f<0.1 where f: focal length of the whole lens system n: refractive index of the lens r1: radius of center curvature of the first surface r2: radius of center curvature of the second surface K1: conic constant of the first surface DELTA 2: axial difference between the aspherical face of the outermost circular zone within the effective diameter of the second surface and a reference spherical face having the radius of center curvature of r2 SG2: axial difference of the aspherical face of the outermost circular zone within the effective diameter of the second surface with respect to the center of the second surface.
Inventors
- 👤 Shinsuke Shikama
- 👤 Hiroshi Kida
- 👤 Akira Daijogo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:29
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3105; G; G02; G02B; G02B13/00; G02B13/18; G02B19/00; G02B19/0004; G02B19/0028; G02B19/0033; G02B19/0047; G02B3/00; G02B3/02; G02B3/04; G02B5/00; G02B5/30; G02B5/3025; G02B5/3066; H04N9/3141; H04N9/315; H04N9/3167
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
145 words
A condenser lens consisting of a bi-aspherical single lens having a first surface of convex form facing the larger conjugate side and a second surface facing the smaller conjugate side and whose outermost circular zone is formed concave, said condenser lens satisfying the following conditions: 0.42<r1/nf<0.45 18<|r2/nf|-0.39<K1<-0.25 0.11<Δ2/f<0.14 where f: focal length of the whole lens system n: refractive index of the lens r1: radius of center curvature of the first surface r2: radius of center curvature of the second surface K1: conic constant of the first surface Δ2: axial difference between the aspherical face of the outermost circular zone within the effective diameter of the second surface and a reference spherical face having the radius of center curvature of r2, wherein the direction in which the outermost circular zone of the second surface is curving toward the smaller conjugate side is taken as positive.
Claim 2
Dependent Claim
145 words
A condenser lens consisting of a bi-aspherical single lens having a first surface of convex form facing the larger conjugate side and a second surface facing the smaller conjugate side and whose outermost circular zone is formed concave, said condenser lens satisfying the following conditions: 0.42<r1/nf<0.45 18<|r2/nf|-0.39<K1<-0.25 0.11<Δ2/f<0.14 where f: focal length of the whole lens system n: refractive index of the lens r1: radius of center curvature of the first surface r2: radius of center curvature of the second surface K1: conic constant of the first surface Δ2: axial difference between the aspherical face of the outermost circular zone within the effective diameter of the second surface and a reference spherical face having the radius of center curvature of r2, wherein the direction in which the outermost circular zone of the second surface is curving toward the smaller conjugate side is taken as positive.
Claim 3
Dependent Claim
16 words
A condenser lens according to claim 1, wherein the numerical aperture (NA) is 0.9 or larger.
Claim 4
Dependent Claim
35 words
A condenser lens according to claim 1, wherein a larger diameter portion outside the effective diameter of the second surface is formed as a plane face perpendicular to the optical axis of said condenser lens.
Claim 5
Dependent Claim
35 words
A condenser lens according to claim 1, wherein a larger diameter portion outside the effective diameter of the first surface is formed as a plane face perpendicular to the optical axis of said condenser lens.
Claim 6
Dependent Claim
142 words
A condenser lens consisting of a bi-aspherical single lens having a first surface of convex form facing the larger conjugate side and a second surface facing the smaller conjugate side and whose outermost circular zone is formed concave, said condenser lens satisfying the following conditions: 0.4<r1/nf<0.6 -0.5<r2/nf<-0.3 -0.6<K1<-0.2 -0.1<SG2/f<0.1 where f: focal length of the whole lens system n: refractive index of the lens r1: radius of center curvature of the first surface r2: radius of center curvature of the second surface K1: conic constant of the first surface SG2: axial different of the aspherical face of the outermost circular zone within the effective diameter of the second surface with respect to the center of the second surface, wherein the direction in which the outermost circular zone of the second surface is curving toward the smaller conjugate side is taken as positive.
Claim 7
Dependent Claim
142 words
A condenser lens consisting of a bi-aspherical single lens having a first surface of convex form facing the larger conjugate side and a second surface facing the smaller conjugate side and whose outermost circular zone is formed concave, said condenser lens satisfying the following conditions: 0.4<r1/nf<0.6 -0.5<r2/nf<-0.3 -0.6<K1<-0.2 -0.1<SG2/f<0.1 where f: focal length of the whole lens system n: refractive index of the lens r1: radius of center curvature of the first surface r2: radius of center curvature of the second surface K1: conic constant of the first surface SG2: axial different of the aspherical face of the outermost circular zone within the effective diameter of the second surface with respect to the center of the second surface, wherein the direction in which the outermost circular zone of the second surface is curving toward the smaller conjugate side is taken as positive.
Claim 8
Dependent Claim
16 words
A condenser lens according to claim 5, wherein the numerical aperture (NA) is 0.9 or larger.
Claim 9
Dependent Claim
35 words
A condenser lens according to claim 5, wherein a larger diameter portion outside the effective diameter of the second surface is formed as a plane face perpendicular to the optical axis of said condenser lens.
Claim 10
Dependent Claim
35 words
A condenser lens according to claim 5, wherein a larger diameter portion outside the effective diameter of the first surface is formed as a plane face perpendicular to the optical axis of said condenser lens.
References Cited (Backward Citations)
US4571034A
Cited
US4641929A
Cited
US4729645A
Cited
US4671623A
Cited
US4743093A
Cited
US4842388A
Cited
JPS6442687A
Cited
US5087115A
Cited
JPH04427A
Cited
US5162949A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-01-23 | 1998-07-25 | 1999-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-23 | 2002-07-25 | 2003-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-23 | 2006-07-25 | 2007-01-24 | $7700.00 | Window Closed / Lapsed |