Eyeglass lens, method for designing eyeglass lens, and method for manufacturing eyeglass lens

Patent metadata

Field	Value
Publication number	US-2019302480-A1
Application number	US-201716307458-A
Country	US
Kind code	A1
Filing date	Jun 6, 2017
Priority date	Jun 6, 2016
Publication date	Oct 3, 2019
Grant date	—

Abstract

In a spectacle lens added with prism thinning, a spherical refractive power of a first refractive portion is positive, and a prism base direction of a prism provided at a prism measurement reference point is set toward a second refractive portion side; a mean value of a difference of a mean curvature in a lens curved surface along a direction passing through a midpoint of a connecting line between two alignment reference marks and orthogonal to the connecting line with respect to a mean curvature in a lens curved surface along a direction of a lens without prism is smaller in a first-refractive-portion-side region from a fitting point than that in a second-refractive-portion-side region from the fitting point.

First claim

1 . A spectacle lens comprising a first refractive portion having a first refractive power, and a second refractive portion having a second refractive power larger than the first refractive power, the spectacle lens being added with prism thinning, wherein
a spherical refractive power of the first refractive portion is positive; a prism base direction of a prism provided at a prism measurement reference point is set toward the second refractive portion side; as a spectacle lens, a spectacle lens that does not include prism thinning is defined as a reference lens; and in a lens curved surface along an orthogonal direction passing through a midpoint of a connecting line between two alignment reference marks of the spectacle lens and being orthogonal to the connecting line, a mean curvature in a direction in which a refractive power decreases from a fitting point in a lens curved surface along the orthogonal direction of the spectacle lens is larger than a mean curvature in the orthogonal direction of the reference lens.

2 . The spectacle lens according to claim 1 , wherein
when a difference between a mean curvature of the reference lens and a mean curvature of the spectacle lens is defined as a mean-curvature difference, a mean value of a mean-curvature difference in a second-refractive-portion-side region with a fitting point as a boundary in the orthogonal direction is larger than a mean value of a mean-curvature difference in a first-refractive-portion-side region.

3 . A spectacle lens comprising a distance portion and a near portion, the spectacle lens being added with prism thinning, wherein
a spherical refractive power of the distance portion is negative or zero, and a prism base direction of a prism provided at a prism measurement reference point is set toward the near portion side; as a spectacle lens, a spectacle lens that does not include prism thinning is defined as a reference lens; and in a lens curved surface along a direction passing through a midpoint of a connecting line between two alignment reference marks of the spectacle lens and being orthogonal to the connecting line, when a difference between a mean curvature of the reference lens and a mean curvature of the spectacle lens is defined as a mean-curvature difference, a value of the mean-curvature difference is 0.02 D or less at a distance-refractive-power measurement point.

4 . A spectacle lens comprising a first refractive portion having a first refractive power, and a second refractive portion having a second refractive power larger than the first refractive power, the spectacle lens being added with prism thinning, wherein
a spherical refractive power of the first refractive portion is positive, and a prism base direction of a prism provided at a prism measurement reference point is set toward the first refractive portion side; as a spectacle lens, a spectacle lens that does not include prism thinning is defined as a reference lens; and in a lens curved surface along an orthogonal direction passing through a midpoint of a connecting line between two alignment reference marks of the spectacle lens and being orthogonal to the connecting line, a mean curvature at least in a direction in which a refractive power decreases from a fitting point in the lens curved surface along the orthogonal direction of the spectacle lens is smaller than a mean curvature in the orthogonal direction of the reference lens.

5 . The spectacle lens according to claim 4 , wherein
when a difference between a mean curvature of the reference lens and a mean curvature of the spectacle lens is defined as a mean-curvature difference, a mean value of a mean-curvature difference in a second-refractive-portion-side region with the fitting point as a boundary in the orthogonal direction is smaller than a mean value of a mean-curvature difference in a first-refractive-portion-side region.

6 . A spectacle lens comprising a distance portion, a near portion, and a corridor, the spectacle lens being added with prism thinning, wherein
a spherical refractive power of the distance portion is negative or zero, and a prism base direction of a prism provided at a prism measurement reference point is set toward the distance portion side; as a spectacle lens, a spectacle lens that does not include prism thinning is defined as a reference lens; and in a lens curved surface along a direction passing through a midpoint of a connecting line between two alignment reference marks of the spectacle lens and being orthogonal to the connecting line, when a difference between a mean curvature of the reference lens and a mean curvature of the spectacle lens is defined as a mean-curvature difference, a value of the mean-curvature difference is 0.02 D or more at a distance-power measurement position.

7 . A designing method for a spectacle lens comprising a first refractive portion having a first refractive power, a second refractive portion having a second refractive power larger than the first refractive power, and a corridor provided between the first refractive portion and the second refractive portion, the spectacle lens being added with prism thinning, the designing method comprising a lens-surface-shape determination step, wherein
in a case where a lens added with a prism corresponding to an amount of the prism thinning is defined as a prism thinning lens; a lens not added with a prism corresponding to an amount of the prism thinning is defined as a reference lens; in the reference lens, incident ray vectors in a case where a plurality of rays are incident on the reference lens to cause a plurality of rays rotated by an angle corresponding to the prism to exit and to be directed toward an eyeball rotation point, are defined as a target ray group; and respective rays emitted from a plurality of object points are incident on an object-side optical surface of the prism thinning lens, and a ray group directed toward each line-of-sight direction of the prism thinning lens among a plurality of rays directed toward an eyeball rotation point among rays exiting from an eyeball-side optical surface of the prism thinning lens is defined as a prism ray group, the lens-surface-shape determination step determines a shape including a slope of the eyeball-side optical surface to cause rays constituting the prism ray group to be parallel to rays of the target ray group passing through a same position.

8 . The designing method for the spectacle lens according to claim 7 , wherein
the lens-surface-shape determination step comprises: a prism-thinning-lens vector storing step of storing an incident ray vector of a ray incident on the object-side optical surface of the prism thinning lens, and an exit ray vector exiting from the eyeball-side optical surface; a target-ray-group storing step of storing the target ray group; a pre-correction prismatic effect calculation step of calculating a prismatic effect of the prism thinning lens before correction from the incident ray vector and the exit ray vector stored in the prism-thinning-lens vector storing step; an ideal prismatic effect calculation step in which, from an incident ray vector stored in the prism-thinning-lens vector storing step and the target ray group stored in the target-ray-group storing step, each angle formed by a direction of an exit ray vector exiting from the reference lens and a direction of an exit ray vector exiting from the prism thinning lens becomes equal at any given point; a correction prism amount calculation step of calculating a correction prism amount in order to correct a slope of the object-side optical surface or the eyeball-side optical surface, based on a difference between a prismatic effect obtained in the pre-correction prismatic effect calculat

Assignees

• Hoya Lens Thailand Ltd

Inventors

• Hatanaka Takashi
• Odaira Tomohiro

Classifications

• G02C7/14

  Mirrors; Prisms · CPC title

• G02C7/061 Primary

  Spectacle lenses with progressively varying focal power · CPC title

• G02C7/024

  Methods of designing ophthalmic lenses · CPC title

• G02C7/022

  Ophthalmic lenses having special refractive features achieved by special materials or material structures (G02C7/049 takes precedence) · CPC title

• G02C7/06 Primary

  bifocal; multifocal {; progressive (G02C7/041 takes precedence)} · CPC title