Method for determining the feasibility of an ophthalmic lens

• US 10,261,341 B2
• Filed: 11/13/2013
• Issued: 04/16/2019
• Est. Priority Date: 11/14/2012
• Status: Active Grant

• Current Assignee: Essilor International SA (EssilorLuxottica SA)
• Original Assignee: Essilor International SA (EssilorLuxottica SA)
• Inventors: Allione, Pascal, Chauveau, Jean-Pierre, Steigelmann, Daniel
• Primary Examiner(s): Pasko, Nicholas R.
• Application Number:
  US14/442,590
• Publication Number:
  US 20160274376A1
• Time in Patent Office: 1,980 Days
• Field of Search: 35115973-15977
• CPC Class Codes: G02C 7/024 Methods of designing ophthalmic lenses
• CPC Class Codes: G02C 7/027 considering wearer's parameters
• CPC Class Codes: G02C 7/028 Special mathematical design techniques

Abstract

Method for determining the feasibility of an ophthalmic lens by an ophthalmic lens manufacturing process comprising: an ophthalmic lens data providing step, a set of surface parameters providing step, an optical parameters providing step during which a set of n optical parameters (P₁, P₂, . . . , P_n) is provided, n being an integer greater than or equal to 1, each optical parameter P_i being provided with a tolerance value ε_i, —a feasibility check determining step, during which the feasibility of the ophthalmic lens by the ophthalmic lens manufacturing process is determined by determining if for i from 1 to n:

$-{\varepsilon }_i\le \left[\sum _{j=1}^m{\left(\frac{\partial P_i}{\partial {\alpha }_j}\right)}_0\times \Delta {\alpha }_j\right]+A_i\le {\varepsilon }_i$$\mathrm{with}{\left(\frac{\partial P_i}{\partial {\alpha }_j}\right)}_0$
the value of the derivative of P_i with respect to the jth surface parameter α_j on the nominal surface and Δα_j the value of the jth surface parameter and A_i a combination of terms of order greater or equal to 2 for each P_i.

Claims

1. A method, comprising:

providing a first manufacturing process to make ophthalmic lenses of a first quality and a second manufacturing process to make ophthalmic lenses of a second quality;

receiving, at a computer having processing circuitry, data representing surfaces of a nominal ophthalmic lens;

receiving, at the computer, a set of m surface parameters (α

₁, α

₂, . . . , α

_m), m being an integer greater than or equal to 1, the surface parameters representing differences in position and/or shape of a surface of the ophthalmic lens with respect to the nominal surface;

receiving, at the computer, a set of n optical parameters (P₁, P₂, . . . , P_n), n being an integer greater than or equal to 1, each optical parameter P_i being provided with a tolerance value ε

_i that is predetermined based on a type of the ophthalmic lens and that is defined in reference to a nominal value P_i,0 being a value of the optical parameter P_i of the nominal ophthalmic lens;

calculating, using the processing circuitry, a feasibility of manufacturing an ophthalmic lens having a particular parameter set by determining whether it is true for i from 1 to n that;

2. The method according to claim 1, wherein, for at least some optical parameters, the calculating of the feasibility includes determining a setting for i from 1 to n:

3. The method according to claim 1, wherein, for some optical parameters, the calculating of the feasibility includes setting A_i=0.

4. The method according to claim 1, wherein at least one optical parameter is an optical parameter selected from among the list consisting of:

spherical power, astigmatism amplitude and axis, vertical prismatic deviation, horizontal prismatic deviation, and total prismatic deviation.

5. The method according to claim 1, wherein at least an optical parameter is defined at at least one reference point selected from among the list consisting of:

a near vision point, a far vision point, a prism reference point, and a fitting cross.

6. The method according to claim 1, wherein at least an optical parameter is an optical parameter defined on a zone corresponding to a vision cone, the vision cone being a cone with the axis of the vision cone passing through the center of rotation of an eye and a reference point of the ophthalmic lens, the aperture of the vision cone being greater than or equal to 5°

and smaller than or equal to 20°

.

7. The method according to claim 1, wherein a value Δ

α

_j derived from the jth surface parameter is an average value of such surface parameter on a surface of the ophthalmic lens.

8. The method according to claim 1, wherein at least one optical parameter is determined under given wearing conditions defined by at least a position of one surface of the ophthalmic lens with respect to a position of a center of rotation of an eye of a wearer and a pantoscopic angle and a wrap angle of the ophthalmic lens.

9. The method according to claim 8, wherein the wearing conditions are defined from measurements on the wearer and a spectacle frame chosen by the wearer.

10. The method according to claim 1, wherein the set of m surface parameters (α

₁, α

₂, . . . , α

_m) comprises at least position parameters and deformation parameters.

11. The method according to claim 10, further comprising:

obtaining a definition of a nominal surface of an ophthalmic lens in a nominal frame of reference and corresponding to a theoretical derivable surface with a nominal value of the position parameters defining the position of the surface with respect to the reference surface;

obtaining a measured surface of the surface expressed in the nominal frame of reference;

obtaining at least one deformation surface defined by at least one deformation adjustable parameter;

determining a composed surface by adding the measured surface and the deformation surface; and

determining the position parameters and at least one deformation parameter by minimizing the difference between the nominal surface and the composed surface.

12. The method according to claim 11, wherein the position parameters comprise at least six parameters of the surface of the ophthalmic lens with respect to the corresponding surface of the nominal ophthalmic lens.

13. The method according to claim 11, wherein the deformation surface corresponds to a sphero-torus surface defined by a sphere parameter, a cylinder parameter and an axis parameter.

14. The method according to claim 11, wherein the deformation surface corresponds to a right circular cone defined by an axis parameter and an angle parameter.