JP3890771B2 - Double-sided aspheric spectacle lens - Google Patents

Description

【０００９】
【表２】

【００１０】
図２に本実施例の遠距離（５００ｍ）、中距離（１ｍ）、近距離（０．３ｍ）における非点収差の度合いを示す。
図３に従来例の遠距離（５００ｍ）、中距離（１ｍ）、近距離（０．３ｍ）における非点収差の度合いを示す。
【００１１】
縁厚については、従来例では縁厚８．４７ｍｍ（表２）であるのに対し、本発明によるレンズでは縁厚７．７３ｍｍ（表１）と大幅に減少している。
非点収差については、従来例（図３）は中距離（１ｍ）の非点収差がよく補正されているが、本発明によるレンズ（図２）もこれとほぼ同程度に補正されている。
【００１２】
（実施例２）
本実施例では、度数Ｓ−６．００Ｄ、レンズ径８０ｍｍ、中心厚１．０ｍｍ、ベースカーブ１．０Ｄ、屈折率ｎ＝１．６７素材の場合を示す。
表３に本実施例の屈折力及び厚みを、表４に従来例の屈折力及び厚みを示す。
【００１３】
【表３】

【００１４】
【表４】

【００１５】
図４に本実施例の遠距離（５００ｍ）、中距離（１ｍ）、近距離（０．３ｍ）における非点収差の度合いを示す。
図５に従来例の遠距離（５００ｍ）、中距離（１ｍ）、近距離（０．３ｍ）における非点収差の度合いを示す。
【００１６】
縁厚については、従来例では縁厚６．７６ｍｍ（表４）であるのに対し、本発明によるレンズでは縁厚７．１６（表３）と若干増加している。
しかしながら、従来例では中心から２５ｍｍ付近から周辺部にかけて屈折力が負となっているため、図６に見られるように蛍光灯の反射が歪んでしまい、外観が悪くなる。
【００１７】
非点収差については、従来例（図５）は中距離（１ｍ）の非点収差がよく補正されているが、本発明によるレンズ（図４）もこれとほぼ同程度に補正されている。
【００１８】
（実施例３）
本実施例では、球面度数Ｓ−６．００Ｄ、乱視度数Ｃ−２．００Ｄ、レンズ径８０ｍｍ、中心厚１．０ｍｍ、ベースカーブ１．０Ｄ、屈折率ｎ＝１．６７素材の場合を示す。
表５に本実施例の屈折力及び厚みを示す。
【００１９】
【表５】

【００２０】
このように乱視レンズにおいても同様の効果が得られる。
【００２１】
【発明の効果】
以上のように本発明によれば、外観を損ねずに最も薄いレンズを提供する効果を有する。
【００２２】
なお、本実施例では説明を簡単にするため、マイナスレンズについて説明したが、プラスレンズについても、本発明の効果を得ることができる。
【図面の簡単な説明】
【図１】本発明の第１の実施例の断面図。
【図２】本発明の第１の実施例の非点収差特性図。
【図３】従来レンズの非点収差特性図。
【図４】本発明の第２の実施例の非点収差特性図。
【図５】従来レンズの非点収差特性図。
【図６】従来例の正面図。
【符号の説明】
１・・・前方屈折面
２・・・後方屈折面
３・・・蛍光灯の反射[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a spectacle lens, and more particularly to a double-sided aspheric spectacle lens capable of reducing the protrusion amount and edge thickness of the lens without deteriorating optical performance and improving the appearance.
[0002]
[Prior art]
The spectacle lens has a lower optical performance in the peripheral part that is farther from the center than the optical performance in the central part. A spherical shape (for example, Japanese Patent Laid-Open Nos. 3-213821 and 4-195019) has been proposed. In the conventional double-sided aspheric lens, both surfaces are aspherical, so that the projection amount and the center thickness of the central portion are reduced in the plus lens, and the edge thickness is reduced in the minus lens.
[0003]
[Problems to be solved by the invention]
However, in the prior art, there is no index to provide a thin lens without damaging the appearance most. If the appearance is important, the thinness is not sufficient. If the importance is attached to the thinness, the appearance is impaired. I was sorry. For example, if thinness is emphasized and the meridian direction refractive power is excessively reduced, the meridian direction refractive power becomes negative. On the refracting surface where the refractive power changes from positive to negative, the reflection of the fluorescent lamp looks distorted, so the appearance is bad. However, if the meridian direction refractive power is not sufficiently reduced, the lens becomes thick.
In view of this, an object of the present invention is to provide a thin lens without damaging the appearance most.
[0004]
[Means for Solving the Problems]
1. The double-sided aspherical single-focus lens according to the present invention is a double-sided aspherical spectacle lens in which both the front refracting surface and the back refracting surface have an axially symmetric aspherical shape, and the meridian of an arbitrary point on the refracting surface with the smaller refractive power. The directional refractive power monotonously decreases in the range of 30 mm or less from the center to the periphery, and the absolute value of the meridional refractive power is 0.5 D or less in the range of 5 mm or less from the outermost periphery. .
[0005]
2. The double-sided aspherical monofocal lens according to the present invention is a double-sided aspherical spectacle lens in which the front refracting surface has an axisymmetric aspherical shape and the rear refracting surface has an aspherical astigmatic surface. On the other refracting surface, the refractive power in the meridian direction on at least one meridian monotonously decreases in the range within 30 mm from the center to the peripheral part, and in the range within 5 mm from the outermost periphery, the absolute value of the refractive power in the meridian direction Is 0.5D or less.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The double-sided aspherical single focus lens of the present invention will be described in detail with reference to examples.
[0007]
Example 1
FIG. 1 is a cross-sectional view of a first embodiment of the present invention. The symbols in the figure are the front refractive surface 1 and the rear refractive surface 2. In the present embodiment, the case of a power of S-6.00D, a lens diameter of 80 mm, a center thickness of 1.0 mm, a base curve of 4.0D, and a refractive index n = 1.67 is shown.
Table 1 shows the refractive power ((n−1) / r, n = refractive index, r = curvature radius) and thickness of this example, and Table 2 shows the refractive power and thickness of the conventional example.
[0008]
[Table 1]

[0009]
[Table 2]

[0010]
FIG. 2 shows the degree of astigmatism in this embodiment at a long distance (500 m), a medium distance (1 m), and a short distance (0.3 m).
FIG. 3 shows the degree of astigmatism at a long distance (500 m), a medium distance (1 m), and a short distance (0.3 m) in the conventional example.
[0011]
With respect to the edge thickness, the edge thickness is 8.47 mm (Table 2) in the conventional example, whereas the edge thickness of the lens according to the present invention is significantly reduced to 7.73 mm (Table 1).
Regarding astigmatism, the conventional example (FIG. 3) corrects astigmatism at medium distance (1 m) well, but the lens according to the present invention (FIG. 2) is also corrected to substantially the same extent.
[0012]
(Example 2)
In the present embodiment, a case where the power is S-6.00D, the lens diameter is 80 mm, the center thickness is 1.0 mm, the base curve is 1.0D, and the refractive index n = 1.67 is shown.
Table 3 shows the refractive power and thickness of this example, and Table 4 shows the refractive power and thickness of the conventional example.
[0013]
[Table 3]

[0014]
[Table 4]

[0015]
FIG. 4 shows the degree of astigmatism at a long distance (500 m), a medium distance (1 m), and a short distance (0.3 m) in this example.
FIG. 5 shows the degree of astigmatism at a long distance (500 m), a medium distance (1 m), and a short distance (0.3 m) in the conventional example.
[0016]
As for the edge thickness, the edge thickness is 6.76 mm (Table 4) in the conventional example, whereas the edge thickness is slightly increased to 7.16 (Table 3) in the lens according to the present invention.
However, in the conventional example, since the refractive power is negative from about 25 mm to the periphery from the center, the reflection of the fluorescent lamp is distorted as shown in FIG.
[0017]
Regarding astigmatism, the conventional example (FIG. 5) corrects astigmatism at a medium distance (1 m) well, but the lens according to the present invention (FIG. 4) is also corrected to substantially the same degree.
[0018]
(Example 3)
In this embodiment, the case of a spherical power S-6.00D, an astigmatism power C-2.00D, a lens diameter 80 mm, a center thickness 1.0 mm, a base curve 1.0D, and a refractive index n = 1.67 is shown.
Table 5 shows the refractive power and thickness of this example.
[0019]
[Table 5]

[0020]
As described above, the same effect can be obtained in the astigmatic lens.
[0021]
【The invention's effect】
As described above, the present invention has an effect of providing the thinnest lens without deteriorating the appearance.
[0022]
In the present embodiment, for the sake of simplicity, the minus lens has been described, but the effect of the present invention can also be obtained with a plus lens.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a first embodiment of the present invention.
FIG. 2 is an astigmatism characteristic diagram of the first embodiment of the present invention.
FIG. 3 is an astigmatism characteristic diagram of a conventional lens.
FIG. 4 is an astigmatism characteristic diagram of the second embodiment of the present invention.
FIG. 5 is an astigmatism characteristic diagram of a conventional lens.
FIG. 6 is a front view of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Front refractive surface 2 ... Back refractive surface 3 ... Reflection of a fluorescent lamp

Claims (2)

In a double-sided aspheric spectacle lens in which both the front refracting surface and the rear refracting surface have an axisymmetric aspheric shape, the meridian power at any point of the refracting surface with the smaller refractive power is 30 mm from the center to the periphery. The absolute value of the refractive power in the meridian direction is 0.5 diopter (hereinafter referred to as D) or less within a range within 5 mm from the outermost periphery, and the non-double-sided feature. Spherical spectacle lens. The front refracting surface has an axisymmetric aspherical shape, the rear refracting surface is a refracting surface used for correcting the astigmatic state of the eye, and the principal meridian shape is not a circular arc (hereinafter referred to as an aspherical astigmatic surface). The refractive power in the meridian direction on at least one meridian decreases monotonously within a range of 30 mm from the center to the periphery on the refractive surface with the smaller refractive power. A double-sided aspheric spectacle lens in which the absolute value of the meridian direction refractive power is 0.5D or less within a range of 5 mm from the outermost periphery.

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