Patent US3838910A successfully refreshed from Google Patents.
US3838910A
Expired / Lapsed
US
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Three element projection lens
Assignee: Eastman Kodak Co
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Filing: 1973-04-24
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Granted: 1974-10-01
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Expires: 1993-04-24
Abstract
Abstract A projection lens comprising three air spaced elements, namely a positive meniscus element, a negative biconcave middle element and a positive biconvex rear element, with each element being formed of a glass having an index of refraction in excess of 1.90 or an Abbe number less than 40.
Inventors
- 👤 P Ruben
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:02
CPC Classifications
G; G02; G02B; G02B9/00; G02B9/12; G02B9/14; G02B9/16; G02B13/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
85 words
,A three element lens comprising, from front to rear, a positive meniscus element, a biconcave negative element and a biconvex positive element, each of said elements being formed of a glass having an index of refraction in excess of 1.90, wherein the lens has a focal length F and the radii of curvature, R, the thicknesses, T, and the air spaces, S, as numbered by subscript from front to rear, are as defined by the following inequalities: 0.40F<R1<0.50F1.5F<R2<2.0F1.8F<-R3<2.4F0.35F<R4<0.45F 0.90F<R5<1.0F 0.90F<-R6<1.0F 0.10F<T1<0.20F 0.05F<T2<0.10F 0.10F<T3<0.20F 0.05F<S1<0.15F 0.05F<S2<0.10F
Claim 2
Dependent Claim
85 words
,A three element lens comprising, from front to rear, a positive meniscus element, a biconcave negative element and a biconvex positive element, each of said elements being formed of a glass having an index of refraction in excess of 1.90, wherein the lens has a focal length F and the radii of curvature, R, the thicknesses, T, and the air spaces, S, as numbered by subscript from front to rear, are as defined by the following inequalities: 0.40F<R1<0.50F1.5F<R2<2.0F1.8F<-R3<2.4F0.35F<R4<0.45F 0.90F<R5<1.0F 0.90F<-R6<1.0F 0.10F<T1<0.20F 0.05F<T2<0.10F 0.10F<T3<0.20F 0.05F<S1<0.15F 0.05F<S2<0.10F
Claim 3
Dependent Claim
40 words
A three element projection lens comprising, from front to rear, a positive meniscus element, a biconcave element and a biconvex element, said lens having a focal length of 100 millimeters when constructed according to the parameters in the following table:
Claim 4
Dependent Claim
40 words
A three element projection lens comprising, from front to rear, a positive meniscus element, a biconcave element and a biconvex element, said lens having a focal length of 100 millimeters when constructed according to the parameters in the following table:
Claim 5
Dependent Claim
40 words
A three element projection lens comprising, from front to rear, a positive meniscus element, a biconcave element and a biconvex element, said lens having a focal length of 100 millimeters when constructed according to the parameters in the following table:
Claim 6
Dependent Claim
40 words
A three element projection lens comprising, from front to rear, a positive meniscus element, a biconcave element and a biconvex element, said lens having a focal length of 100 millimeters when constructed according to the parameters in the following table:
Claim 7
Dependent Claim
40 words
A three element projection lens comprising, from front to rear, a positive meniscus element, a biconcave element and a biconvex element, said lens having a focal length of 100 millimeters when constructed according to the parameters in the following table:
Claim 8
Dependent Claim
40 words
A three element projection lens comprising, from front to rear, a positive meniscus element, a biconcave element and a biconvex element, said lens having a focal length of 100 millimeters when constructed according to the parameters in the following table:
Claim 9
Dependent Claim
40 words
A three element projection lens comprising, from front to rear, a positive meniscus element, a biconcave element and a biconvex element, said lens having a focal length of 100 millimeters when constructed according to the parameters in the following table:
Claim 10
Dependent Claim
40 words
A three element projection lens comprising, from front to rear, a positive meniscus element, a biconcave element and a biconvex element, said lens having a focal length of 100 millimeters when constructed according to the parameters in the following table:
Claim 11
Dependent Claim
88 words
A three element lens comprising, from front to rear, a positive meniscus element, a biconcave negative element and a biconvex positive element, each of said elements being formed of a glass having a Abbe number which is less than 40, wherein the lens has a focal length F and the radii of curvature, R, the thicknesses, T, and the air spaces, S, as numbered by subscript fron front to rear, are as defined by the following inequalities: 0.40F<R1<0.50F 1.5F<R2<2.0F 1.8F<-R3<2.4F 0.35F<R4<0.45F 0.90F<R5<1.0F 0.90F<-R6<1.0F 0.10F<T1<0.20F 0.05F<T2<0.10F 0.10F<T3<0.20F 0.05F<S1<0.15F 0.05F<S2<0.10F
Claim 12
Dependent Claim
88 words
A three element lens comprising, from front to rear, a positive meniscus element, a biconcave negative element and a biconvex positive element, each of said elements being formed of a glass having a Abbe number which is less than 40, wherein the lens has a focal length F and the radii of curvature, R, the thicknesses, T, and the air spaces, S, as numbered by subscript fron front to rear, are as defined by the following inequalities: 0.40F<R1<0.50F 1.5F<R2<2.0F 1.8F<-R3<2.4F 0.35F<R4<0.45F 0.90F<R5<1.0F 0.90F<-R6<1.0F 0.10F<T1<0.20F 0.05F<T2<0.10F 0.10F<T3<0.20F 0.05F<S1<0.15F 0.05F<S2<0.10F
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-30 | 1978-04-01 | 1978-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-30 | 1982-04-01 | 1982-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-30 | 1986-04-01 | 1986-10-01 | $7700.00 | Window Closed / Lapsed |