US4881805A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Progressive intensity phase bifocal
Assignee: Individual
•
Filing: 1987-11-12
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Granted: 1989-11-21
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Expires: 2007-11-12
Abstract
Abstract An ophthalmic contact lens containing more than one phase plate within its optic zone, including contact lens, especially of a Cohen lens design, which possesses phase plate optics within its optic zone that progressively shift the intensity of light focussed by bifocal phase plates between the diffractive focal powers by utilizing eshelettes in the phase plates of varying depths and heights which are cooperatively aligned relative to the lens base curve surface that they openly face.
Inventors
- 👤 Allen L. Cohen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:41
CPC Classifications
G; G02; G02C; G02C7/00; G02C7/02; G02C7/04; G02C7/041; G02C7/044; G02B; G02B5/00; G02B5/18; G02B5/1876; G02B5/189; G02B5/1895; G02C7/042; G02C2202/00; G02C2202/20
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
16 words
An ophthalmic contact or intraocular lens containing more than one phase plate within its optic zone.
Claim 2
Dependent Claim
16 words
An ophthalmic contact or intraocular lens containing more than one phase plate within its optic zone.
Claim 3
Dependent Claim
21 words
The ophthalmic contact or intraocular lens of claim 1 wherein there are at least two phase plates within the optic zone.
Claim 4
Dependent Claim
19 words
The ophthalmic contact or intraocular lens of claim 1 wherein each phase plate obeys the same phase plate formula.
Claim 5
Dependent Claim
29 words
The ophthalmic contact or intraocular lens of claim 3 wherein the formula is: r.sub.m =√2 m w f w=the wavelength of light f=focal length of 1 st order diffraction.
Claim 6
Dependent Claim
65 words
The ophthalmic contact or intraocular lens of claim 1 in which the lens possesses phase plate optics within its optic zone that progressively shift the intensity of light focussed by bifocal phase plates between the diffractive focal powers by utilizing echelettes in the phase plates of varying depths and heights which are cooperatively aligned relative to the lens base curve surface that they openly face.
Claim 7
Dependent Claim
19 words
The ophthalmic contact or intraocular lens of claim 5 in which the lens is of a Cohen lens design.
Claim 8
Dependent Claim
23 words
The ophthalmic contact or intraocular lens of claim 6 in which each of the individual phase plates obeys the same phase plate formula.
Claim 9
Dependent Claim
29 words
The ophthalmic contact or intraocular lens of claim 7 wherein the formula is: r.sub.m =√2 m w f w=the wavelength of light f=focal length of 1 st order diffraction.
Claim 10
Dependent Claim
21 words
The ophthalmic contact or intraocular lens of claim 8 wherein the echelette depths are monotonically increasing from the lens center outward.
Claim 11
Dependent Claim
21 words
The ophthalmic contact or intraocular lens of claim 8 wherein the echelette depths are monotonically decreasing from the lens center outward.
Claim 12
Dependent Claim
24 words
The ophthalmic contact or intraocular lens of claim 6 wherein each echelette is set back from the base curve according to its specific depth.
Claim 13
Dependent Claim
46 words
The ophthalmic contact or intraocular lens of claim 6 wherein the deepest echelettes have a depth h and are placed to touch the base curve of the lens, and each echelette of a differing depth ah are set back a distance b=(1-a)/2 from the base curve.
Claim 14
Dependent Claim
21 words
The ophthalmic contact or intraocular lens of claim 11 wherein the echelette depths are monotonically increasing from the lens center outward.
Claim 15
Dependent Claim
35 words
The ophthalmic contact or intraocular lens of claim 11 wherein each echelette is set back from the base curve according to its specific depth in such a manner that allows for drapage of the lens.
Claim 16
Dependent Claim
77 words
The ophthalmic contact or intraocular lens of claim 14 wherein the deepest echelettes have a depth h and are placed to touch the base curve of the lens, other echelette of a differing depth ah are set back a distance c from the base curve where c is given by the formula c=bh(n'-n)/(n-1), with n' equal to the refractive index of the contact lens and n equal to the refractive index of tear layer of the eye.
Claim 17
Dependent Claim
21 words
The ophthalmic contact or intraocular lens of claim 14 wherein the echelette depths are monotonically increasing from the lens center outward.
Claim 18
Dependent Claim
60 words
The ophthalmic contact or intraocular lens of claim 14 wherein the echelette depths are monotonically decreasing from the lens center outward and where the peripheral portion of the lens is cut back from the base curve at least to the point where it lays tangent to the outermost echelettes so as to allow for full drapage of the contact lens.
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) | 1992-11-20 | 1993-05-22 | 1993-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-20 | 1997-05-22 | 1997-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-20 | 2001-05-22 | 2001-11-21 | $7700.00 | Window Closed / Lapsed |