Method of manufacture of molds for resin ophthalmic lenses having a segment with prismatic optical effect

Claim 1

A method for making a mold for the casting of resin ophthalmic lenses and the like having a segment locally of the lens which has prismatic optical effect relative to the remainder of the lens, the method including the steps of (a) forming in one face of a first blank an optically finished first surface which is a portion of a first surface of revolution having a first axis of symmetry, (b) providing a second blank of characteristics sufficiently compatible with those of the first blank that the first and second blanks can be stably adhered together and which has formed at least partially therethrough a recess of predetermined size and perimetral shape, (c) forming in one side of the second blank a second surface which is essentially reversely curved to that of the first surface in such manner that the recess opens to the second surface upon completion of the formation of the second surface, (d) registering the first and second blanks with each other with the first and second surfaces in opposition, (e) adhering the registered blanks together to define a resulting blank, (f) forming in that face of the resulting blank which was opposite from the second surface of the second blank, and without eliminating the recess entirely from the resulting blank, an optically finished third surface to which the first surface opens via the recess and which is a portion of a second surface of revolution having a second axis of symmetry with an effective center of curvature located along the second axis, including forming the third surface in such manner that the first and second axes intersect, if at all, at a location on the second axis other than at substantially said center of curvature.

Claim 2

A method for making a mold for the casting of resin ophthalmic lenses and the like having a segment locally of the lens which has prismatic optical effect relative to the remainder of the lens, the method including the steps of (a) forming in one face of a first blank an optically finished first surface which is a portion of a first surface of revolution having a first axis of symmetry, (b) providing a second blank of characteristics sufficiently compatible with those of the first blank that the first and second blanks can be stably adhered together and which has formed at least partially therethrough a recess of predetermined size and perimetral shape, (c) forming in one side of the second blank a second surface which is essentially reversely curved to that of the first surface in such manner that the recess opens to the second surface upon completion of the formation of the second surface, (d) registering the first and second blanks with each other with the first and second surfaces in opposition, (e) adhering the registered blanks together to define a resulting blank, (f) forming in that face of the resulting blank which was opposite from the second surface of the second blank, and without eliminating the recess entirely from the resulting blank, an optically finished third surface to which the first surface opens via the recess and which is a portion of a second surface of revolution having a second axis of symmetry with an effective center of curvature located along the second axis, including forming the third surface in such manner that the first and second axes intersect, if at all, at a location on the second axis other than at substantially said center of curvature.

Claim 18

A method for making a mold for the casting of resin ophthalmic lenses and the like having a segment locally of the lens which has prismatic optical effect relative to the remainder of the lens, the method including the steps of (a) forming in the entire area of one face of a first blank an optically finished first surface which is a portion of a first surface of revolution having a first axis of symmetry, (b) providing a second blank of characteristics sufficiently compatible with those of the first blank that the first and second blanks can be stably adhered together and which has formed at least partially therethrough a recess of predetermined size and perimetral shape, the second blank except for the recess being sufficiently large to cover the first blank, (c) forming in one side of the second blank a second surface which is essentially reversely curved to that of the first surface in such manner that the recess opens to the second surface upon completion of the formation of the second surface and which is of sufficient area except for the recess to cover the first surface, (d) registering the first and second blanks with each other with the first and second surfaces in opposition, (e) adhering the registered blanks together without altering the curvature of the first surface to define a resulting blank in which the first surface is covered except for the presence of the recess, (f) forming in that face of the resulting blank which was opposite from the second surface of the second blank, and without eliminating the recess entirely from the resulting blank, an optically finished third surface which is a portion of a second surface of revolution having a second axis of symmetry with an effective center of curvature located along the second axis, including forming the third surface in such manner that the first and second axes intersect, if at all, at a location on the second axis other than at substantially said center of curvature.

Claim 19

A method for making a mold for the casting of resin ophthalmic lenses and the like having a segment locally of the lens which has prismatic optical effect relative to the remainder of the lens, the method including the steps of (a) forming in the entire area of one face of a first blank an optically finished first surface which is a portion of a first surface of revolution having a first axis of symmetry, (b) providing a second blank of characteristics sufficiently compatible with those of the first blank that the first and second blanks can be stably adhered together and which has formed at least partially therethrough a recess of predetermined size and perimetral shape, the second blank except for the recess being sufficiently large to cover the first blank, (c) forming in one side of the second blank a second surface which is essentially reversely curved to that of the first surface in such manner that the recess opens to the second surface upon completion of the formation of the second surface and which is of sufficient area except for the recess to cover the first surface, (d) registering the first and second blanks with each other with the first and second surfaces in opposition, (e) adhering the registered blanks together without altering the curvature of the first surface to define a resulting blank in which the first surface is covered except for the presence of the recess, (f) forming in that face of the resulting blank which was opposite from the second surface of the second blank, and without eliminating the recess entirely from the resulting blank, an optically finished third surface which is a portion of a second surface of revolution having a second axis of symmetry with an effective center of curvature located along the second axis, including forming the third surface in such manner that the first and second axes intersect, if at all, at a location on the second axis other than at substantially said center of curvature.