US3905685A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zoom lens for fixed conjugates
Assignee: Xerox Corp
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Filing: 1974-02-13
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Granted: 1975-09-16
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Expires: 1994-02-13
Abstract
Abstract Heliar, Dagor and Gauss lens systems, by way of example, are converted to zoom lens systems by severing outer lens elements and displacing the severed elements equal distances but in opposite directions relative to the main body of the system. The curvatures of severed elements are critical and are discovered by empirical procedures.
Inventors
- 👤 David C Harper
- 👤 George L Mccrobie
- 👤 Edgar E Price
- 👤 Joachim A Ritter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:45
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/24; G02B15/00; G02B15/14; G02B15/142
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
146 words
A variofocal lens system including, in optical alignment along an optical axis: a central lens, a pair of doublets, one on each side of said central lens, said doublets including an inner lens element having a first refractive index and a first dispersion and an outer lens element having a second refractive index and a second lower dispersion, a pair of movable single lenses, one on the outward side of each of said doublets, said movable single lenses being of the same material as the adjacent outward element of said doublets and having an inner radius of curvature substantially identical to the outer radius of curvature of said doublets, said movable single lenses being arranged for symmetrical movement along said optical axis relative to their adjacent doublets while the entire system is moved relative to the object to vary the focal length of said lens system.
Claim 2
Dependent Claim
146 words
A variofocal lens system including, in optical alignment along an optical axis: a central lens, a pair of doublets, one on each side of said central lens, said doublets including an inner lens element having a first refractive index and a first dispersion and an outer lens element having a second refractive index and a second lower dispersion, a pair of movable single lenses, one on the outward side of each of said doublets, said movable single lenses being of the same material as the adjacent outward element of said doublets and having an inner radius of curvature substantially identical to the outer radius of curvature of said doublets, said movable single lenses being arranged for symmetrical movement along said optical axis relative to their adjacent doublets while the entire system is moved relative to the object to vary the focal length of said lens system.
Claim 3
Dependent Claim
37 words
A varifocal lens system as defined in claim 1 in which said central lens is a single biconcave lens and said doublets and said movable single lenses are arranged in symmetry with respect to said central lens.
Claim 4
Dependent Claim
141 words
A variofocal lens system including, in optical alignment along an optical axis: a pair of doublets each including inner and outer lens elements, said inner lens elements having a first refractive index and a first dispersion and said outer lens elements having a second refractive index and a second lower dispersion, a pair of movable single lenses, one on the outward side of each of said doublets, said movable single lenses being of the same material as the adjacent outward element of said doublets and each having an inner radius of curvature substantially identical to the outer radius of curvature of its adjacent doublet, said movable single lenses being arranged for symmetrical movement along said optical axis relative to their adjacent doublets while the entire system is moved relative to the object to vary the focal length of said lens system.
Claim 5
Dependent Claim
141 words
A variofocal lens system including, in optical alignment along an optical axis: a pair of doublets each including inner and outer lens elements, said inner lens elements having a first refractive index and a first dispersion and said outer lens elements having a second refractive index and a second lower dispersion, a pair of movable single lenses, one on the outward side of each of said doublets, said movable single lenses being of the same material as the adjacent outward element of said doublets and each having an inner radius of curvature substantially identical to the outer radius of curvature of its adjacent doublet, said movable single lenses being arranged for symmetrical movement along said optical axis relative to their adjacent doublets while the entire system is moved relative to the object to vary the focal length of said lens system.
Claim 6
Dependent Claim
145 words
A variofocal lens system including, in optical alignment along an optical axis: a central lens, a pair of doublets, one on each side of said central lens, said doublets including an inner lens element having a first refractive index and a first dispersion and an outer lens element having a second refractive index and a second lower dispersion, a pair of movable single lenses, one on the outward side of each of said doublets, said movable single lenses being of the same material as the adjacent outward element of said doublets and having an inner radius of curvature substantially identical to the outer radius of curvature of said doublets, said movable single lenses being arranged for movement along said optical axis relative to their adjacent doublets while the entire system is moved relative to the object to vary the focal length of said lens system.
Claim 7
Dependent Claim
145 words
A variofocal lens system including, in optical alignment along an optical axis: a central lens, a pair of doublets, one on each side of said central lens, said doublets including an inner lens element having a first refractive index and a first dispersion and an outer lens element having a second refractive index and a second lower dispersion, a pair of movable single lenses, one on the outward side of each of said doublets, said movable single lenses being of the same material as the adjacent outward element of said doublets and having an inner radius of curvature substantially identical to the outer radius of curvature of said doublets, said movable single lenses being arranged for movement along said optical axis relative to their adjacent doublets while the entire system is moved relative to the object to vary the focal length of said lens system.
Claim 8
Dependent Claim
140 words
A variofocal lens system including, in optical alignment along an optical axis: a pair of doublets each including inner and outer lens elements, said inner lens elements having a first refractive index and a first dispersion and said outer lens elements having a second refractive index and a second lower dispersion, a pair of movable single lenses, one on the outward side of each of said doublets, said movable single lenses being of the same material as the adjacent outward element of said doublets and each having an inner radius of curvature substantially identical to the outer radius of curvature of its adjacent doublet, said movable single lenses being arranged for movement along said optical axis relative to their adjacent doublets while the entire system is moved relative to the object to vary the focal length of said lens system.
Claim 9
Dependent Claim
140 words
A variofocal lens system including, in optical alignment along an optical axis: a pair of doublets each including inner and outer lens elements, said inner lens elements having a first refractive index and a first dispersion and said outer lens elements having a second refractive index and a second lower dispersion, a pair of movable single lenses, one on the outward side of each of said doublets, said movable single lenses being of the same material as the adjacent outward element of said doublets and each having an inner radius of curvature substantially identical to the outer radius of curvature of its adjacent doublet, said movable single lenses being arranged for movement along said optical axis relative to their adjacent doublets while the entire system is moved relative to the object to vary the focal length of said lens system.
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) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |