Method for determining a base system of diffraction gratings for color fringe correction of spectacle lenses

• US 9,022,560 B2
• Filed: 11/16/2011
• Issued: 05/05/2015
• Est. Priority Date: 11/17/2010
• Status: Active Grant

• Current Assignee: Rodenstock GmbH (Bridgepoint Advisers Group Limited)
• Original Assignee: Rodenstock GmbH (Bridgepoint Advisers Group Limited)
• Inventors: Becken, Wolfgang, Esser, Gregor, Altheimer, Helmut, Wehner, Edda, Trumm, Stephan, Mueller, Werner, Uttenweiler, Dietmar
• Primary Examiner(s): Sugarman, Scott J
• Assistant Examiner(s): Alexander, William R
• Application Number:
  US13/988,239
• Publication Number:
  US 20130235337A1
• Time in Patent Office: 1,266 Days
• Field of Search: 351/159.01, 351/159.42, 351/159.44, 351/159.75, 351/159.76, 700/95
• US Class Current: 351/159.42
• CPC Class Codes: G02C 2202/20 Diffractive and Fresnel lenses or lens portions
• CPC Class Codes: G02C 2202/22 Correction of higher order and chromatic aberrations, wave front measurement and calculation
• CPC Class Codes: G02C 7/02 Lenses; Lens systems ; Methods of designing lenses
• CPC Class Codes: G02C 7/022 Ophthalmic lenses having special refractive features achieved by special materials or material structures G02C7/049 takes precedence
• 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 7/06 bifocal; multifocal ; progressive G02C7/041 takes precedence
• CPC Class Codes: G02C 7/061 Spectacle lenses with progressively varying focal power
• CPC Class Codes: G02C 7/068 Special properties achieved by the combination of the front and back surfaces

Abstract

A method for producing a series of base lenses, which cover a predetermined power range, wherein each base lens of the series has a base power different from the base powers of the other base lenses of the series, and has at least one diffractive base grating, the method comprising: specifying the base powers of each base lens of the series and calculating the base grating of each base lens of the series so as to minimize the color fringe of the respective base lens with the specified base power in a predetermined region of the spectacle lens.

Claims

1. A method for producing a series of base lenses, which cover a predetermined power range, wherein the base lenses are lens blanks, each base lens of the series has a base power, which is different from the base powers of the other base lenses of the series, and each base lens of the series has at least one diffractive base grating, the method comprising:

assigning one correction range to each of the base lenses;

specifying the base powers of each base lens of the series, wherein the base powers are specified such that the correction ranges of the individual base lenses cover the predetermined power range; and

calculating the base grating of each base lens of the series so as to minimize the color fringe in a predetermined region of a spectacle lens manufactured from the base lens and having the specified base power,

wherein

the base grating of the base lens in the respective correction range corrects the color fringe of a spectacle lens with a power within the correction range assigned to the base lens such that the color fringe of the spectacle lens within a predetermined region of the spectacle lens is smaller than or equal to a predetermined threshold, and

the predetermined region of the spectacle lens within which the maximum color fringe is smaller than or equal to the predetermined threshold has a diameter of at least 40 mm, and the predetermined threshold is 0.5 cm/m.

2. The method according to claim 1, wherein the base lenses are spherocylindrical or spherical single-vision lenses.

3. The method according to claim 1, wherein calculating the base grating comprises simultaneously optimizing at least one of the refractive surfaces of the base lens and of the base grating.

4. The method according to claim 1, wherein the grating lines of the respective base grating are elliptical.

5. The method according to claim 1, wherein the grating lines of the respective base grating are rotationally symmetric.

6. The method according to claim 5, wherein the distance of the grating lines of each of the base gratings is calculated as a function of the radial distance d(r) from the optical or geometric center according to the formula

7. The method according to claim 1, wherein specifying the base powers is performed such that the condition

8. The method according to claim 1, wherein the power range to be covered comprises at least one of spherical powers of −

12 dpt to +12 dpt and cylindrical powers of up to 4 dpt.

29. The method according to claim 1, at least one of wherein the predetermined region of the spectacle lens within which the maximum color fringe is smaller than or equal to the predetermined threshold has a diameter of at least 40 mm, and wherein the predetermined threshold is 0.4 cm/m.

30. The method according to claim 1, at least one of wherein the predetermined region of the spectacle lens within which the maximum color fringe is smaller than or equal to the predetermined threshold has a diameter of at least 40 mm, and wherein the predetermined threshold is 0.12 cm/m.

31. The method according to claim 1, wherein the power range to be covered comprises at least one of spherical powers of −

12 dpt to +12 dpt and cylindrical powers of up to 6 dpt.

9. A device for producing a series of base lenses that cover a predetermined power range, wherein the base lenses are lens blanks, each base lens of the series has a base power, which is different from the base powers of the other base lenses of the series, and each base lens of the series has at least one diffractive base grating, comprising:

base grating calculator adapted to calculate the base grating of each of the spectacle lenses of the series, wherein calculating comprises assigning one correction range to each of the base lenses and specifying the base powers of each base lens of the series, wherein the base powers are specified such that the correction ranges of the individual base lenses cover the predetermined power range; and

is performed so as to minimize the color fringe in a predetermined region of a spectacle lens manufactured from the base lens and having the specified base power, wherein

the base grating of the base lens in the respective correction range corrects the color fringe of a spectacle lens with a power within the correction range assigned to the base lens such that the color fringe of the spectacle lens within a predetermined region of the spectacle lens is smaller than or equal to a predetermined threshold, and

the predetermined region of the spectacle lens within which the maximum color fringe is smaller than or equal to the predetermined threshold has a diameter of at least 40 mm; and

the predetermined threshold is 0.5 cm/m.

10. A series of base lenses comprising at least two base lenses, wherein each base lens of the series is a lens blank and comprises:

each base lens of the series is configured for a base power different from the base powers of the other base lenses of the series, and

each base lens of the series has at least one diffractive base grating adapted such that the maximum color fringe within a predetermined region of a spectacle lens manufactured from the base lens having the specified base power with a diameter of at least 40 mm is equal to or smaller than a predetermined threshold of 0.5 cm/m, wherein;

each of the base lenses of the series is assigned a correction range such that the base grating of the base lens in the respective correction range corrects the color fringe of a spectacle lens with a power within the correction range assigned to the base lens such that the color fringe of the spectacle lens within the predetermined region of the spectacle lens is smaller than or equal to the predetermined threshold, and

the power distance of the base lenses of the series is such that the correction ranges of the individual base lenses cover a predetermined power range.

11. The series of base lenses according to claim 10, wherein the maximum color fringe within the predetermined region of the spectacle lens is smaller than or equal to 0.4 cm/m.

12. The series of base lenses according to claim 10, wherein the predetermined power range comprises at least one of spherical powers from −

12 dpt to +12 dpt and cylindrical powers of up to 4 dpt.

13. The series of base lenses according to claim 10, wherein the number of base lenses is between 5 and 20.

14. The series of base lenses according to claim 10, wherein the base lenses are single-vision lenses, multifocal lenses, or progressive lenses.

15. The series of base lenses according to claim 10, wherein the base grating is applied to at least one of the front surface and to the back surface of each of the base lenses, or wherein the base grating is applied to at least one boundary surface in the interior of the compound system comprising a main lens and a cover lens.

16. The series of base lenses according to claim 10, wherein the at least one diffractive base grating is a diffraction grating with elliptically extending grating lines.

17. The series of base lenses according to claim 10, wherein the at least one diffractive base grating is a diffraction grating with rotationally symmetrically extending grating lines.

18. The series of base lenses according to claim 17, wherein it holds for the distance of the grating lines of each of the base gratings as a function of the radial distance d(r) from the optical or geometric center of the respective base lens that:

19. The series of base lenses according to claim 10, wherein the maximally existing distance |Δ

M_0G| of the spherical equivalents of the base lenses of the series satisfies the condition

20. The series of base lenses according to claim 10, wherein the grating structures of the individual base gratings are realized by switchable structures.

21. A method for producing a spectacle lens, comprises:

obtaining prescription data of a spectacles wearer, wherein the prescription data comprises at least one spherical prescription power;

determining the target power of the spectacle lens in at least one predetermined reference point of the spectacle lens depending on the obtained prescription data;

selecting a base lens from the series of base lenses with the features according to claim 12 depending on the obtained prescription data or on the target power of the spectacle lens; and

machining the base lens such that the power of the finished spectacle lens in the at least one reference point is substantially equal to the previously determined target power in said reference point.

22. A device for producing a spectacle lens, comprising:

obtaining means for obtaining prescription data of a spectacles wearer, wherein the prescription data comprises at least one spherical prescription power;

target power calculating means for determining the target power of the spectacle lens in at least one predetermined reference point of the spectacle lens depending on the obtained prescription data;

selecting means for selecting a base lens from the series of base lenses with the features according to claim 10 depending on the obtained prescription data or on the target power of the spectacle lens; and

machining means for machining the base lens such that the power of the finished spectacle lens in the at least one reference point is substantially equal to the previously determined target power in said reference point.

32. The series of base lenses according to claim 10, wherein the maximum color fringe within the predetermined region of the spectacle lens is smaller than or equal 0.12 cm/m.

33. The series of base lenses according to claim 10, wherein the predetermined power range comprises at least one of spherical powers from −

12 dpt to +12 dpt and cylindrical powers of up to 6 dpt.

23. A series of spectacle lenses with different powers, which cover a power range of at least −

12 dpt to +12 dpt of the spherical power, wherein each spectacle lens of the series is a lens blank and has at least one diffraction grating, and wherein the number of the different gratings of all spectacle lenses of the series is smaller than the number of spectacle lenses, and

wherein the maximum color fringe of each of the spectacle lenses of the series within a predetermined region with a diameter of at least 40 mm is equal to or smaller than a predetermined threshold of 0.5 cm/m.

24. The series of spectacle lenses according to claim 23, wherein the predetermined power range further comprises cylindrical powers of up to 4 dpt.

25. The series of spectacle lenses according to claim 23, wherein the number of different gratings is between 5 and 20.

26. The series of spectacle lenses according to claim 23, wherein the spectacle lenses are single-vision lenses, multi-focal lenses, or progressive lenses.

27. The series of spectacle lenses according to claim 23, wherein the at least one diffraction grating of each spectacle lens of the series is a diffraction grating with elliptically or rotationally symmetrically extending grating lines.

28. The series of spectacle lenses according to claim 23, wherein the grating structures of the individual base lenses are realized by switchable structures.

34. The series of spectacle lenses according to claim 23, wherein the predetermined power range further comprises cylindrical powers of up to 6 dpt.