Method for precision polishing non-planar, aspherical surfaces
AssigneeEastman Kodak Company
InventorDavid A. Richards
Life of this patent
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Abstract
A method for precison polishing non-planar, aspherical surfaces in substrates, particularly surfaces of molding tool substrates for molding optical surfaces therewith, which is accomplished by coating the non-planar, aspherical surface with a layer of material having a melt temperature which is less than a temperature at which the substrate will distort, heating the layer of material coated on the non-planar, aspherical surface to at least the melt temperature thereby flowing the layer of material to yield a surface tension smooth surface superimposed over the non-planar, aspherical surface, and etching the surface tension smooth surface down into the substrate to completely remove the layer.
Claims19
A method for fabricating molding tools for molding optical surfaces therewith, said method comprising the steps of:
- (a) precision fine grinding a substrate to achieve a surface with an excellent surface figure;
- (b) coating the surface with a layer of material which wets the substrate and has a melt temperature which is less than a temperature at which the substrate will distort;
- (c) heating the layer of material coated on the surface to at least the melt temperature;
- (d) flowing the layer of material to yield a specular surface therein superimposed over said surface;
- and
- (e) etching the layer of material down into the substrate to completely remove the layer.
A method for fabricating molding tools for molding optical surfaces therewith, said method comprising the steps of:
- (a) precision fine grinding a substrate to achieve a surface with an excellent surface figure and with a surface roughness of no more than about 100 .ANG. RMS;
- (b) coating the surface with a layer of material having a melt temperature which is less than a temperature at which the substrate will distort, the layer of material wetting the substrate;
- (c) heating the layer of material coated on the surface to at least the melt temperature thereby flowing the layer of material to form a surface tension smooth specular surface therein superimposed over said surface;
- and
- (d) etching the surface tension smooth specular surface down into the substrate to completely remove the layer.
A method for fabricating molding tools for molding optical surfaces therewith, said method comprising the steps of:
- (a) generating a surface with an excellent surface figure in a substrate to achieve a surface roughness of no more than about 100 .ANG. RMS;
- (b) coating the surface with a layer of material which wets the surface of the substrate and has a melt temperature which is less than a temperature at which the substrate will distort;
- (c) heating the layer of material coated on the surface to at least the melt temperature thereby flowing the layer of material to yield a surface tension smooth surface therein superimposed over said surface;
- and
- (d) etching the surface tension smooth surface down into the substrate to completely remove the layer.
A method for fabricating molding tools for molding optical surfaces therewith, said method comprising the steps of:
- (a) generating a surface with an excellent surface figure in a substrate to achieve a surface roughness of no more than about 100 .ANG., said substrate having a first hardness;
- (b) coating the surface with a layer of material which wets the substrate and has a melt temperature which is less than a glass transition temperature of the substrate;
- (c) heating the layer of material coated on the surface to at least the melt temperature thereby flowing the layer of material to yield a specular surface therein superimposed over said surface;
- and
- (d) oxidizing the specular surface to achieve a second hardness of at least approximates the first hardness.
A method for polishing a non-planar, aspherical surface having a surface roughness of no more than about 100 .ANG. RMS, said method comprising the steps of:
- (a) coating the non-planar, aspherical surface with a layer of material which wets the non-planar, aspherical surface and has a melt temperature which is less than a temperature at which the substrate will distort;
- (b) heating the layer of material coated on the non-planar, aspherical surface to at least the melt temperature thereby flowing the layer of material to yield a surface tension smooth surface therein superimposed over said surface;
- and
- (c) etching the surface tension smooth surface down into the substrate to completely remove the layer.
Dependencies are inferred from the claim text.