Patent US3684357A successfully refreshed from Google Patents.
US3684357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fused bifocal contact lens unit
Assignee: Individual
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Filing: 1970-01-19
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Granted: 1972-08-15
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Expires: 1990-01-19
Abstract
Abstract A fused bifocal contact lens having ''''no jump'''' characteristics at all points of the segment line separating the distant vision segment of zone from the near vision zone. The lens include conventional convex and concave surfaces on the exterior portions, but, by reason of the construction of the bifocal segment, the wearer does not experience double vision when his line of sight crosses the segment line and the wearer does not notice the presence of the bifocal segment when not looking therethrough. In one form, a full, concentric bifocal segment is provided, and in another form, a lens is provided in which the bifocal segment is of a bi-curve form, lies principally in the lower portion of the lens and is defined by an upper, outer curve and an inner curve forming a partially circular segment line across which there is no jump. Methods of forming such lenses, including the method of forming the near vision segment, forming a composite blank including both distant and near vision segments, and forming a bifocal lens from the composite blank, are described.
Inventors
- 👤 George F Tsuetaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:40
CPC Classifications
G; G02; G02C; G02C7/00; G02C7/02; G02C7/04; G02C7/049; G02C7/041; G02C7/043; G02C7/044; G02C7/045; G02C2202/00; G02C2202/16
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
174 words
A bifocal contact lens unit having a generally convex front lens surface portion and a generally concave rear lens surface portion and including a distant vision portion and a bifocal segment portion fused in place within said lens unit and partially defined by a segment front surface portion having a given radius of curvature and a plurality of centers of radial curvature, and an at least partially annular, generally axially extending, generally radially inwardly facing inner segment surface portion meeting said rear lens surface along a given line and meeting said segment front surface along a segment line, each of said centers of radial curvature lying on a given sight line between a center of curvature of said rear lens surface portion and the point on said segment line intersected by said given sight line, whereby said lens is characterized by the absence of image displacement when the sight line of a user crosses any portion of said radially inner surface of said bifocal segment at any point along said inner segment surface portion.
Claim 2
Dependent Claim
174 words
A bifocal contact lens unit having a generally convex front lens surface portion and a generally concave rear lens surface portion and including a distant vision portion and a bifocal segment portion fused in place within said lens unit and partially defined by a segment front surface portion having a given radius of curvature and a plurality of centers of radial curvature, and an at least partially annular, generally axially extending, generally radially inwardly facing inner segment surface portion meeting said rear lens surface along a given line and meeting said segment front surface along a segment line, each of said centers of radial curvature lying on a given sight line between a center of curvature of said rear lens surface portion and the point on said segment line intersected by said given sight line, whereby said lens is characterized by the absence of image displacement when the sight line of a user crosses any portion of said radially inner surface of said bifocal segment at any point along said inner segment surface portion.
Claim 3
Dependent Claim
38 words
A lens unit as defined in claim 1 in which said at least partially annular inner segment surface portion is completely annular, said bifocal segment being fully annular and totally surrounding said distant vision portion of said lens.
Claim 4
Dependent Claim
58 words
A lens unit as defined in claim 1 in which said partially annular inner segment surface portion extends through an arc of about one-half of a circle, said bifocal segment having edge surfaces extending radially outwardly from the ends of said inner surface portion and occupying about one-half of said complete lens unit when viewed from the front.
Claim 5
Dependent Claim
27 words
A lens unit as defined in claim 1 in which said given radius of curvature of said segment front surface portion is a constant radius of curvature.
Claim 6
Dependent Claim
24 words
A lens as defined in claim 1 wherein said center of curvature of said rear lens surface portion is a single center of curvature.
Claim 7
Dependent Claim
44 words
A lens as defined in claim 1 in which said lens front surface portion has a center of curvature lying at a point offset from a sight line extending from said rear lens surface center of curvature to the center of said lens unit.
Claim 8
Dependent Claim
80 words
A lens as defined in claim 1 in which said bifocal segment is further defined by a radially outer edge portion lying generally parallel to the outer edge of said lens, wherein said segment line occupies about one-half of a circle, wherein said radially outer edge portion of said bifocal segment subtends a greater angle than said segment line, and wherein generally radially disposed segment lines extend between respective outer ends of said segment line and said outer edge portions.
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) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |