Optical system determination according to advanced criteria

• US 9,104,041 B2
• Filed: 10/16/2009
• Issued: 08/11/2015
• Est. Priority Date: 10/16/2008
• Status: Active Grant

• Current Assignee: Essilor International SA
• Original Assignee: Essilor International SA
• Inventors: De Rossi, Hlne, Muradore, Fabien
• Primary Examiner(s): Suglo, Janet
• Assistant Examiner(s): BLOSS, STEPHANIE E
• Application Number:
  US13/124,757
• Publication Number:
  US 20110202286A1
• Time in Patent Office: 2,125 Days
• Field of Search: 702/19, 702/182, 351/177, 351/159.73, 351/159.77, 351/159.41
• US Class Current: 1/1
• CPC Class Codes: G02C 7/02 Lenses; Lens systems ; Methods of designing lenses
• CPC Class Codes: G02C 7/024 Methods of designing ophthalmic lenses
• CPC Class Codes: G02C 7/028 Special mathematical design techniques
• CPC Class Codes: G02C 7/061 Spectacle lenses with progressively varying focal power

Abstract

A method implemented by computer means for calculating by optimization an optical system for example an ophthalmic lens according to at least one criterion among the following list consisting of: ocular deviation, object visual angular field in central vision, image visual angular field in central vision, pupil field ray deviation, object visual angular field in peripheral vision, image visual angular field in peripheral vision, prismatic deviation in peripheral vision, magnification in peripheral vision, lens volume, magnification of the eyes, temple shift, or a variation of preceding criteria.

Claims

1. A method for manufacturing an optical system comprising the steps of:

i. selecting at least one criterion from among the groups consisting of;

a central vision criteria group consisting of;

ocular deviation, object visual angular field in central vision, image visual angular field in central vision, and a variation of preceding criteria;

a peripheral vision criteria group consisting of;

pupil field ray deviation, object visual angular field in peripheral vision, image visual angular field in peripheral vision, prismatic deviation in peripheral vision, magnification in peripheral vision, and a variation of preceding criteria; and

a general criteria group consisting of;

lens volume, magnification of the eyes, and temple shift;

ii. for each criterion selected in step i.), defining;

an evaluation zone comprising one or several evaluation domains and a set of target values associated with said evaluation domains, if said criterion selected in step i.) belongs to the central or to the peripheral vision criteria groups, or

a target value associated with said criterion selected in step i.), if said criterion belongs to the general criteria group;

iii. selecting a starting optical system and defining a working optical system to be equal to the starting optical system, wherein the starting optical system and the working optical system are each defined by coefficients of equations of its surfaces, an index of glasses thereof, and positions of each surface relative to each other, and wherein each optical system comprises at least two optical surfaces of a same lens;

iv. evaluating for the working optical system and for each criterion selected in step i.);

a set of criterion values associated with said evaluation domains selected in step ii.), if said criterion selected in step i.) belongs to the central or peripheral vision criteria groups, or

a criterion value, if said criterion selected in step i.) belongs to the general criteria group;

v. modifying at least coefficients of equations of the at least two optical surfaces of the working optical system to minimize a cost function considering target values and criterion values by repeating step iv.) until a stop criterion is satisfied, wherein the at least two optical surfaces comprise at least a front and a back surface;

vi. calculating by optimization the optical system; and

vii. surface machining at least one optical surface in accordance with said calculated optical system.

2. The method according to claim 1, wherein the cost function is a sum over the criteria selected in step i.) of:

sums, over the evaluation domains of step ii.) or differences between a criterion value associated with an evaluation domain of step ii.) and the target value associated with said evaluation domain to the power of two, for criteria selected in step i.) belonging to the central vision and peripheral vision criteria groups, and

differences between a criterion value and a target value of step ii.) to the power of two, for criteria selected in step i.) belonging to the general criteria group.

3. The method according to claim 1, wherein the criterion selected in step i.) belongs to the central vision criteria group and wherein the associated evaluation domains of step ii.) comprise at least one gaze direction, said direction being considered with regard to reference axes associated with the eye rotation center and used to perform ray tracing from the eye rotation center for the criterion evaluation.

4. The method according to claim 3, wherein the criterion selected in step i.) belongs to any of:

ocular deviation, pupil field ray deviation, prismatic deviation in peripheral vision, magnification in peripheral vision, and wherein the associated evaluation domains consist in one direction.

5. The method according to claim 3, wherein the criterion selected in step i.) belongs to any of object visual angular field in central vision, image visual angular field in central vision, object visual angular field in peripheral vision and image visual angular field in peripheral vision, and wherein the associated evaluation domains comprise of at least two directions.

6. The method according to claim 3, wherein the criterion selected in step i.) is defined either by a variation of the criterion selected in step i.) belonging to the central vision criteria group or by a variation of the criterion selected in step i.) belonging to the peripheral vision criteria group.

7. The method according to claim 1, wherein a selected criterion of step i.) belongs to the peripheral vision criteria group and the associated evaluation domains of step ii.) comprise at least one peripheral ray direction, said direction being considered with regard to reference axes associated with the entrance pupil center moving along a determined gaze direction and used to perform ray tracing from the entrance pupil center for the criterion evaluation.

8. The method according to claim 7, wherein the criterion selected in step i.) belongs to any of:

ocular deviation, pupil field ray deviation, prismatic deviation in peripheral vision, or magnification in peripheral vision, and wherein the associated evaluation domains consist in one direction.

9. The method according to claim 7, wherein the criterion selected in step i.) belongs to any of object visual angular field in central vision, image visual angular field in central vision, object visual angular field in peripheral vision or image visual angular field in peripheral vision, and wherein the associated evaluation domains comprise of at least two directions.

10. The method according to claim 7, wherein the criterion selected in step i.) is defined either by a variation of the criterion selected in step i.) belonging to the central vision criteria group or by a variation of the criterion selected in step i.) belonging to the peripheral vision criteria group.

11. The method according to claim 1, wherein the cost function J is mathematically expressed according to:

12. An apparatus capable of carrying out steps i.) to vii.) of claim 1.

13. The method according to claim 1, wherein the central vision criteria group further comprises astigmatism criterion and/or power criterion.

14. The method according to claim 1, wherein the optical system is a progressive addition lens and the central vision criteria group further comprises add power criterion.