EP0145392A2
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EP
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Optical element with a varying refractive index and a method for its manufacture
Assignee: Eastman Kodak Co
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Filing: 1984-11-26
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Granted: —
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Expires: 2004-11-26
Abstract
Abstract An optical element, consisting essentially of an amorphous compound and having a refractive index which varies throughout the element, is prepared by introducing a melt of the material into a mold and cooling it in such a manner that the material gradually solidifies, while simultaneously applying a programmed pressure to the cooling melt. When the material is fully solidified, it possesses a refractive index gradient. An element manufactured by this method has a capacity for guiding and focusing light.
Inventors
- 👤 Jehuda Greener
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 18:16
CPC Classifications
B; B29; B29D; B29D11/00; B29D11/00663; B29D11/00682; B29D11/00009; B29D11/00355; B29C; B29C35/00; B29C35/16; B29K; B29K2995/00; B29K2995/0018; B29K2995/0031; B29K2995/0037; B29K2995/0039
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
46 words
A method for the manufacture of an optical element having a refractive index gradient, comprising the steps of: (1) cooling a molten amorphous material in such a manner as to cause it to gradually solidify; while simultaneously (2) varying the pressure applied to the amorphous material.
Claim 2
Independent Claim
46 words
A method for the manufacture of an optical element having a refractive index gradient, comprising the steps of: (1) cooling a molten amorphous material in such a manner as to cause it to gradually solidify; while simultaneously (2) varying the pressure applied to the amorphous material.
Claim 3
Dependent Claim
53 words
The method of Claim 1 characterized in that the cooling takes place in a mold, the temperature of the mold is maintained below the glass transition temperature of said material so as to cause gradual solidification of said material and s subsequent to step (2), the solidified material is removed from the mold.
Claim 4
Dependent Claim
11 words
The method of Claim 2 wherein the mold is cylindrically shaped.
Claim 5
Dependent Claim
19 words
The method of Claim 1, 2 or 3 wherein the pressure applied to the amorphous material is gradually increased.
Claim 6
Dependent Claim
21 words
5 . The method of Claim 1, 2 or 3 wherein the pressure applied to the amorphous material is gradually decreased.
Claim 7
Dependent Claim
117 words
A method of Claim 1 wherein step (1) comprises: introducing a molten amorphous polymeric material into a cylindrically-shaped cavity in a mold; step (2) comprises maintaining the temperature of the mold below the glass transition temperature of said material so as to cause solidification of said material first at the outer circumference of the cylinder, then gradually along the radial axis of the cylinder, and finally at the longitudinal axis of the cylinder; while simultaneously gradually changing pressure applied to the amorphous material from one end of the cylinder; and subsequent to step (2), removing the solid cylinder of amorphous polymeric material from the mold and cutting said solid cylinder along its circular face into circular disks.
Claim 8
Independent Claim
17 words
The method of any one of preceding Claims 1 to 6 wherein the amorphous material is polystyrene.
Claim 9
Dependent Claim
16 words
An optical element consisting essentially of an amorphous material, said element having a refractive index gradient.
Claim 10
Dependent Claim
16 words
An optical element consisting essentially of an amorphous material, said element having a refractive index gradient.
Claim 11
Dependent Claim
53 words
The optical element of Claim 8 having a continuous refractive index gradient capable of guiding and focusing light, wherein the refractive index varies in a direction perpendicular to the optical axis of the element as a function of the distance from the center of the element to the outer surface of the element.
Claim 12
Dependent Claim
15 words
The element of Claim 3 or 9 wherein the amorphous compound is an organic polymer.
Claim 13
Dependent Claim
38 words
The element of Claim 8, 9 or 10 wherein the refractive index increases uniformly in a direction perpendicular to the optical axis of the element from the center of the element to the outer surface of the element.
Claim 14
Dependent Claim
27 words
The element of Claim 8, 9 or 10 wherein the refractive index decreases steadily from the center of the element to the outer surface of the element.
Claim 15
Dependent Claim
73 words
A cylindrically shaped optical element having an optical axis coexistent with the longitudinal axis of the cylinder consisting essentially of an amorphous compound, the element having a gradient in refractive index capable of guiding and focusing light, wherein the refractive index changes in a direction perpendicular to the optical axis of the element as a function of the radial distance from the center of the element to the outer surface of the element.
Claim 16
Dependent Claim
73 words
A cylindrically shaped optical element having an optical axis coexistent with the longitudinal axis of the cylinder consisting essentially of an amorphous compound, the element having a gradient in refractive index capable of guiding and focusing light, wherein the refractive index changes in a direction perpendicular to the optical axis of the element as a function of the radial distance from the center of the element to the outer surface of the element.
References Cited (Backward Citations)
No citation records indexed.
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