US3609013A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Symmetrical four-component photocopying lens system
Assignee: Ricoh Co Ltd
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Filing: 1970-03-26
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Granted: 1971-09-28
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Expires: 1990-03-26
Abstract
Abstract A holosymmetrical photocopying lens system with a field angle of 53* and an aperture ratio of 1 : 4.5 is provided. Within the range from c-line (565.3 m Mu ) to g-line (435.8 m Mu ), both of the spherical aberration and astigmatism are well corrected with a resolution of 20 lines/mm.
Inventors
- 👤 Motoaki Kawazu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:53
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
187 words
A holosymmetrical photocopying lens system for use with a unit magnification comprising six individual lenses in four groups satisfying the following conditions: aperture ratio: 1:4.5 field angle: 53* r1 (-r10) 0.284724f r2 (-r9) 2.017807f r3 (-r8) 0.208707f r4 (-r7) 0.298009f r5 (-r6) 0.449099f d1 d9 0.038625f d2 d8 0.056605f d3 d7 0.0183130f d4 d6 0.024640f d5 0.047282f n1 n6 1.717 n2 n5 1.62588 n3 n4 1.68578 V1 V6 47.9 V2 V5 35.6 V3 V4 44.0 where r with a numerical subscript is a radius of curvature of a surface of a lens in the order of numerals from the first lens facing an object to be reproduced; d with a numerical subscript is a distance or thickness along the optical axis of said lens system of a lens or airspace between adjacent lenses in the order of numerals from said first lens; n with a numerical subscript is a refractive index by d-line of a lens in the order of numerals from said first lens; and v with a numerical subscript is an Abbe number of a lens in the order of numerals from said first lens.
Claim 2
Dependent Claim
187 words
A holosymmetrical photocopying lens system for use with a unit magnification comprising six individual lenses in four groups satisfying the following conditions: aperture ratio: 1:4.5 field angle: 53* r1 (-r10) 0.284724f r2 (-r9) 2.017807f r3 (-r8) 0.208707f r4 (-r7) 0.298009f r5 (-r6) 0.449099f d1 d9 0.038625f d2 d8 0.056605f d3 d7 0.0183130f d4 d6 0.024640f d5 0.047282f n1 n6 1.717 n2 n5 1.62588 n3 n4 1.68578 V1 V6 47.9 V2 V5 35.6 V3 V4 44.0 where r with a numerical subscript is a radius of curvature of a surface of a lens in the order of numerals from the first lens facing an object to be reproduced; d with a numerical subscript is a distance or thickness along the optical axis of said lens system of a lens or airspace between adjacent lenses in the order of numerals from said first lens; n with a numerical subscript is a refractive index by d-line of a lens in the order of numerals from said first lens; and v with a numerical subscript is an Abbe number of a lens in the order of numerals from said first lens.
References Cited (Backward Citations)
US3221601A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |