Method And Apparatus For Manufacturing Ophthalmic Lenses
In a method of manufacturing an ophthalmic lens, a target value for an optical property is selected ( 500 ) for the ophthalmic lens. A first mold member ( 400 ) is formed ( 505 ) for cast-molding the ophthalmic lens in combination with a second mold member. A property of the first mold member ( 400 ) is measured ( 510 ), the measured property correlating with the optical property of the ophthalmic lens. A determination ( 520 ) is made as to whether the measured property of the first mold member ( 400 ) is consistent with the target value of the optical property of the ophthalmic lens. If the measured property of the first mold member ( 400 ) is consistent with the target value of the optical property of the ophthalmic lens, the manufacture of the ophthalmic lens continues ( 530 ). If the measured property of the first mold member ( 400 ) is not consistent with the target value of the optical property of the ophthalmic lens, the first mold member ( 400 ) is discarded ( 540 ).
1 - 15 . (canceled)
16 . A method of manufacturing an ophthalmic lens, the method including the steps:
(a) selecting a target value for an optical power for the ophthalmic lens;
(b) forming a first mold member for cast-molding the ophthalmic lens in combination with a second mold member;
(c) measuring a property of the first mold member, the measured property correlating with the optical power of the ophthalmic lens;
(d) determining whether the measured property of the first mold member is consistent with the target value of the optical power of the ophthalmic lens;
wherein the property of the first mold member is measured by transmitting light through the first mold member; wherein
if the measured property of the first mold member is consistent with said target value of the optical power, within predetermined tolerances, passing the first mold member to a mold assembly apparatus and continuing with the manufacture of the ophthalmic lens and otherwise discarding the first mold member.
17 . The method of claim 16 , wherein the property of the first mold member is measured by measuring focusing or defocusing properties of the mold member.
18 . The method of claim 16 , wherein the measured property of the first mold member is the same property as the optical property of the lens.
19 . The method of claim 16 , wherein the target optical property of the ophthalmic lens is calculated from the measured property of the first mold member.
20 . The method of claim 16 , further comprising a calibration step, in which the optical property of the ophthalmic lens is measured for a selection of values of the measured property of the first mold member to provide a correspondence record and the correspondence record is used subsequently to determine whether the measured property of the first mold member is consistent with the target value of the optical property of the ophthalmic lens.
21 . The method of claim 16 , wherein the measured property of the first mold member is deemed to be consistent with the target optical property of the ophthalmic lens if the value of the measured property of the first mold member is expected to result in an ophthalmic lens, formed using the first mold member, having a value within 10% of the target value.
22 . The method of claim 16 , wherein the optical property is measured in diopters and the ophthalmic lens is expected to have the optical property to within +/−0.25 D of the target value.
23 . The method of claim 16 , wherein, if the measured property of the first mold member is consistent with the target value of the optical property of the ophthalmic lens, the continued manufacture includes the step of repeating said method for the second mold member.
24 . The method of claim 16 , wherein, if the measured property of the first mold member is not consistent with the target value of the optical property of the ophthalmic lens, the first mold member is discarded completely.
25 . The method of claim 16 , wherein, if the measured property of the first mold member is not consistent with the target value of the optical property of the ophthalmic lens, the first mold member is returned to an earlier stage in the manufacturing process.
26 . The method of claim 16 , wherein the determination as to whether the measured property of the first mold member is consistent with the target value of the optical property of the ophthalmic lens is done as part of an initial set-up check, prior to forming any ophthalmic lenses.
27 . The method of claim 16 , wherein the determination is carried out on every first mold member, or every mold member, of one or more batches of mold members used in the method.
28 . An apparatus for manufacturing an ophthalmic lens, the apparatus comprising:
(a) a database including a target value for an optical power for the ophthalmic lens and a correlation of said target value with a property of a first mold member;
(b) injection-molding apparatus for forming the first mold member for cast-molding the ophthalmic lens in combination with a second mold member;
(c) measurement apparatus for measuring the property of the first mold member by transmitting light through the first mold member;
(d) a processor configured to determine whether the measured property of the first mold member is consistent with the target value of the optical power of the ophthalmic lens and to, if the measured property of the first mold member is consistent with said target value within predetermined tolerances, pass the first mold member to a mold assembly apparatus for continuation of the manufacture of the ophthalmic lens, and to otherwise provide a signal indicating that the first mold member is to be rejected.