US4952048A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of designing a non-progressive multifocal ophthalmic lens
Assignee: Opticorp Inc
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Filing: 1989-06-26
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Granted: 1990-08-28
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Expires: 2009-06-26
Abstract
Abstract The present invention relates to a multifocal ophthalmic lens which comprises a first substantially spherical area for distance viewing, a second substantially spherical area for near viewing having a desired width and height and being surrounded on a plurality of sides by the first area, and relatively narrow areas intermediate the first and second areas for blending the second area into the first area. The lens design of the present invention may also include an optional third substantially spherical area adjacent the second area for increasing the near viewing range in a substantially contiguous manner.
Inventors
- 👤 Philip M. Frieder
- 👤 Michael Walach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:28
CPC Classifications
G; G02; G02C; G02C7/00; G02C7/02; G02C7/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
119 words
A method of designing a non-progressive ophthalmic lens having a distance viewing area and at least one other viewing area, said method comprising: forming a first arc segment defining a portion of a substantially spherical far distance viewing area having a prescribed power; forming a second arc segment defining a portion of a second viewing area having a desired power and a top portion coinciding with said first arc segment for a first distance; and blending said first and second arc segments together in areas where said segments do not coincide, said lens being characterized by substantially no image jump, no visible line segment at said top portion and no separation through a center region of said top portion.
Claim 2
Independent Claim
119 words
A method of designing a non-progressive ophthalmic lens having a distance viewing area and at least one other viewing area, said method comprising: forming a first arc segment defining a portion of a substantially spherical far distance viewing area having a prescribed power; forming a second arc segment defining a portion of a second viewing area having a desired power and a top portion coinciding with said first arc segment for a first distance; and blending said first and second arc segments together in areas where said segments do not coincide, said lens being characterized by substantially no image jump, no visible line segment at said top portion and no separation through a center region of said top portion.
Claim 3
Dependent Claim
75 words
The method of claim 1 wherein said first arc segment forming step comprises: establishing a first center of curvature for said far distance viewing area; determining a first radius of curvature for said far distance viewing area based upon said prescribed power for said far distance viewing area; and drawing said first arc segment defining said far distance viewing area, said first arc segment having a central axis passing through said first center of curvature.
Claim 4
Dependent Claim
107 words
The method of claim 2 wherein said second arc segment forming step comprises: selecting a first point along said first arc segment at a desired distance below said central axis, said first point defining the top portion of the second arc segment; drawing a first line tangent to said first arc segment at said first point; drawing a first line perpendicular to said first tangent line; determining a second radius of curvature for said second viewing area; establishing a second center of curvature by measuring a distance equal to said second radius along said first perpendicular line; and drawing said second arc segment for a desired distance.
Claim 5
Dependent Claim
42 words
The method of claim 3 further comprising: forming a third arc segment defining a portion of a third viewing area having a desired power, said third arc segment having a top portion coiciding with said second arc segment for a second distance.
Claim 6
Dependent Claim
109 words
The method of claim 4 wherein said third arc segment forming step comprises: selecting a second point along said second arc segment at a desired distance below said central axis, said second point defining the top portion of the third arc segment; drawing a second line tangent to said second arc segment at said second point; drawing a second line perpendicular to said second tangent line; determining a third radius of curvature for said third viewing area; establishing a third center of curvature by measuring a distance equal to said third radius of curvature along said second perpendicular line; and drawing said third arc segment for a desired distance.
Claim 7
Dependent Claim
23 words
The method of claim 1 wherein said blending step comprises sinusoidally blending said arc segments together in areas where they do not coincide.
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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) | 1993-08-27 | 1994-02-26 | 1994-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-27 | 1998-02-26 | 1998-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-27 | 2002-02-26 | 2002-08-28 | $7700.00 | Window Closed / Lapsed |