US4738516A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical element having an aspheric surface
Assignee: US Philips Corp
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Filing: 1986-07-10
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Granted: 1988-04-19
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Expires: 2006-07-10
Abstract
Abstract For manufacturing monaspherical lenses, a correction layer of a synthetic resin is provided on a substrate having a spherical surface. In this method, centering is performed by using the curvature of the surface of the matrix. With a correct choice of the radius of curvature of the substrate surface, the substrate approaches the matrix most closely near a collection of inflection points in the matrix surface situated on a circle. A good centering without a guiding mechanism is possible by using the method according to the invention. Moreover, the differences in thickness in the correction layer are small enough to prevent shrinkage defects upon curing of the synthetic resin layer.
Inventors
- 👤 Johannes M. G. Verhoeven
- 👤 Albert Smid
- 👤 Herman M. A. Amendt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:55
CPC Classifications
B; B29; B29D; B29D11/00; B29D11/00009; B29D11/00019; Y; Y10; Y10S; Y10S425/00; Y10S425/808
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
74 words
An optical element comprising: a substrate having an approximately spherical surface with a radius of curvature; and a layer of synthetic resin on the spherical surface of the substrate, said resin layer having an aspherical convex outer surface with a collection of inflection points situated approximately on a circle, said layer having a varying thickness; characterized in that the minimum thickness of the resin layer is located adjacent to the collection of inflection points.
Claim 2
Dependent Claim
74 words
An optical element comprising: a substrate having an approximately spherical surface with a radius of curvature; and a layer of synthetic resin on the spherical surface of the substrate, said resin layer having an aspherical convex outer surface with a collection of inflection points situated approximately on a circle, said layer having a varying thickness; characterized in that the minimum thickness of the resin layer is located adjacent to the collection of inflection points.
Claim 3
Dependent Claim
16 words
An optical element as claimed in claim 1, wherein said synthetic resin is an acrylate resin.
Claim 4
Dependent Claim
18 words
An optical element as claimed in claim 1, wherein said resin is a diglycidyl ether of biphenol A.
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) | 1991-04-19 | 1991-10-19 | 1992-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-19 | 1995-10-19 | 1996-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-19 | 1999-10-19 | 2000-04-19 | $7700.00 | Window Closed / Lapsed |