US3907401A
Expired / Lapsed
US
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High performance optical objective
Assignee: Xerox Corp
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Filing: 1974-07-01
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Granted: 1975-09-23
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Expires: 1994-07-01
Abstract
Abstract A twelve element optical objective which provides a relatively large equivalent focal length and aperture ratio, said objective having high resolving power, while minimizing spherical and chromatic aberrations.
Inventors
- 👤 Wai-Min Liu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:43
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/16; G02B13/02; G02B27/00; G02B27/0025
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
178 words
An optical objective comprising three fixed groups of lens elements, the front fixed lens group comprising a positive lens element which is spaced in front of a positive meniscus lens element which is spaced in front of a negative lens element concave to the front, the second fixed lens group comprising a doublet lens element comprising a negative meniscus lens element the rear surface of which is cemented to a first positive lens element convex to the front spaced in front of a second doublet element comprising a positive meniscus lens the rear surface of which is cemented to the front surface of a negative meniscus lens element concave to the front which is spaced in front of a biconcave lens element which is spaced in front of a second positive lens element convex to the front, and the third fixed lens group comprising a positive meniscus element convex to the front spaced in front of a negative lens element concave to the front spaced in front of a third positive meniscus lens element convex to the front.
Claim 2
Dependent Claim
178 words
An optical objective comprising three fixed groups of lens elements, the front fixed lens group comprising a positive lens element which is spaced in front of a positive meniscus lens element which is spaced in front of a negative lens element concave to the front, the second fixed lens group comprising a doublet lens element comprising a negative meniscus lens element the rear surface of which is cemented to a first positive lens element convex to the front spaced in front of a second doublet element comprising a positive meniscus lens the rear surface of which is cemented to the front surface of a negative meniscus lens element concave to the front which is spaced in front of a biconcave lens element which is spaced in front of a second positive lens element convex to the front, and the third fixed lens group comprising a positive meniscus element convex to the front spaced in front of a negative lens element concave to the front spaced in front of a third positive meniscus lens element convex to the front.
Claim 3
Dependent Claim
21 words
The objective as defined in claim 1 wherein said objective is achromatic over the spectrum from about 7000A to about 9000A.
Claim 4
Dependent Claim
20 words
The objective as defined in claim 1 wherein the equivalent focal length is 24.0 inches and the F/number is 2.0.
Claim 5
Dependent Claim
36 words
The objective as defined In claim 1 wherein distortion is less than 0.20 mm at full field and the modulation transfer function is at least equal to 70 percent at a resolving power of 30 lp/mm.
Claim 6
Dependent Claim
17 words
The objective as defined in claim 1 further including an image tube operatively associated with said objective.
Claim 7
Dependent Claim
13 words
An optical objective made in accordance with the following chart of constructional data:
Claim 8
Dependent Claim
13 words
An optical objective made in accordance with the following chart of constructional data:
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) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |