US5016977A
Expired / Lapsed
US
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Optical lens for correcting astigmatism
Assignee: EssilorLuxottica SA
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Filing: 1990-02-05
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Granted: 1991-05-21
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Expires: 2010-02-05
Abstract
Abstract The present invention relates to an optical lens for correcting astigmatism. It includes diffractive components whose outlines are delimited by conic section curves having non-degenerate centers. More precisely, in accordance with the invention, the lens includes adjacent diffractive components having hyperbolic or elliptical outlines with a periodicity in r 2 in two mutually orthogonal directions x and y intersecting on the axis of the lens and coinciding with the main axes of the hyperbolas or of the ellipses, which are determined respectively by the equations: Δr x 2 =2λ|f x |; and Δr y 2 =2λ|f y |; in which: Δr x 2 represents the periodicity in r 2 along the x direction; Δr y 2 represents the periodicity in r 2 along the y direction; λ represents the mean utilization wavelength; f x represents the desired focal length in the X direction; and f y represents the desired focal length in the Y direction.
Inventors
- 👤 Dominique Baude
- 👤 Pierre Chavel
- 👤 Denis Joyeux
- 👤 Jean Taboury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:18
CPC Classifications
G; G02; G02C; G02C7/00; G02C7/02; G02C7/04; A; A61; A61F; A61F2/00; A61F2/02; A61F2/14; A61F2/145; A61F2/16; A61F2/1613; A61F2/1637; A61F2/164; A61F2/1654; G02B; G02B27/00; G02B27/0025; G02B27/0037; G02B27/42; G02B27/4205; G02B27/4216; G02B5/00; G02B5/18; G02B5/1876; G02B5/188; G02C7/041; G02C7/042; G02C7/045; G02C2202/00; G02C2202/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
111 words
A lens for correcting astigmatism, including adjacent hyperbolic- or elliptical-outline diffractive components whose periodicity in two mutually orthogonal X and Y directions intersecting at the axis of the lens and coinciding with the main axes of the hyperbolas or the ellipses are respectively determined by the equations: Δr.sub.x.sup.2 =2λ|f.sub.x |; and Δr.sub.y.sup.2 =2λ|f.sub.y |; in which: Δr x 2 represents the periodicity in r 2 along the X direction; Δr y 2 represents the periodicity in r 2 along the Y direction; λ represents the means utilization wavelength; f x represents the desired focal length in the X direction; and f y represents the desired focal length in the Y direction.
Claim 2
Dependent Claim
111 words
A lens for correcting astigmatism, including adjacent hyperbolic- or elliptical-outline diffractive components whose periodicity in two mutually orthogonal X and Y directions intersecting at the axis of the lens and coinciding with the main axes of the hyperbolas or the ellipses are respectively determined by the equations: Δr.sub.x.sup.2 =2λ|f.sub.x |; and Δr.sub.y.sup.2 =2λ|f.sub.y |; in which: Δr x 2 represents the periodicity in r 2 along the X direction; Δr y 2 represents the periodicity in r 2 along the Y direction; λ represents the means utilization wavelength; f x represents the desired focal length in the X direction; and f y represents the desired focal length in the Y direction.
Claim 3
Dependent Claim
27 words
A lens according to claim 1, wherein the diffractive components have elliptical outlines defined by the equation: x.sup.2 /|f.sub.x |+y.sup.2 /|f.sub.y |=2λk where k represents an integer.
Claim 4
Dependent Claim
34 words
A lens according to claim 1, wherein the diffractive components have hyperbolic outlines defined by the equations: x.sup.2 /|f.sub.x |-y.sup.2 /|f.sub.y |=2λk; and y.sup.2 /|f.sub.y |-x.sup.2 /|f.sub.x |=2λk in which k represents an integer.
Claim 5
Dependent Claim
15 words
A lens according to claim 1, wherein the diffractive components are made by index variation.
Claim 6
Dependent Claim
22 words
A lens according to claim 1, wherein the diffractive components have a pure kinoform type phase profile varying between 0 and 2π.
Claim 7
Dependent Claim
25 words
A lens according to claim 1, wherein the diffractive components have a sampled kinform type phase profile comprising n subzones at phase differences of 2π/n.
Claim 8
Dependent Claim
24 words
A lens according to claim 1, wherein the diffractive components have a binary phase profile comprising two subzones at a phase difference of π.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-05-20 | 1994-11-19 | 1995-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-20 | 1998-11-19 | 1999-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-20 | 2002-11-19 | 2003-05-21 | $7700.00 | Window Closed / Lapsed |