【特許請求の範囲】
【請求項１】光源から発する光束をコリメートする、正の屈折力を持つ両凸形状の単 レンズであって、前記光源側から順に第１面が球面、第２面が非球面で構成され、
以下の条件式を満足することを特徴とする非球面コリメートレンズ。
｜R２｜＜f＜｜R１｜
１．５＜f／d＜２．５
NA＞０．４５
２．４８＜nF／｜R２'｜＜２．５２
但し、
R１：第１面の曲率半径（但し符号は光源側に凸の形状を正とする）
R２：第２面の頂点曲率半径（但し符号は光源側に凸の形状を正とする）
ｆ：本発明にかかる非球面コリメートレンズのＦ線（波長４８６ｎｍの光線）におけ る焦点距離
ｄ：本発明に係る非球面コリメートレンズの中心厚
ＮＡ：本発明にかかる非球面コリメートレンズの光源側の開口数
ｎＦ：本発明にかかる非球面コリメートレンズのＦ線（波長４８６ｎｍの光線）に おける屈折率
R２'：前記ｆをｆ＝１．０と規格化した時の第２面の頂点曲率半径（但し符号は光源 側に凸の形状を正とする）
【請求項２】
構成材料が硝子であって、かつ以下の条件を満足することを特徴とする、請求項１に記載の非球面コリメートレンズ。
ｎＦ＞１．５５
νｄ＞５５
但し、
νｄ：本発明にかかる非球面コリメートレンズを構成する硝子のアッベ数
【請求項３】
以下の条件式を満足することを特徴とする、請求項２に記載の非球面コリメートレンズ。
Ｔ１＞０．８
Ｔ２＞０．９５
但し、
Ｔ１：前記構成材料の厚みが１０ｍｍのときの、波長３４０ｎｍの光線に対する内部透過率
Ｔ２：前記構成材料の厚みが１０ｍｍのときの、波長４００ｎｍの光線に対する内部透過率
[Claims]
1. A biconvex single lens having a positive refractive power that collimates a light flux emitted from a light source, wherein the first surface is a spherical surface and the second surface is an aspherical surface in order from the light source side.
An aspherical collimating lens characterized by satisfying the following conditional expression.
｜ R2 ｜ ＜ f ＜ ｜ R1 ｜
1.5 <f / d <2.5
NA> 0.45
2.48 <nF / | R2' | <2.52
However,
R1: Radius of curvature of the first surface (however, the sign means that the shape convex toward the light source is positive)
R2: Radius of curvature of the apex of the second surface (however, the sign means that the shape convex toward the light source is positive)
f: Focus distance at F line (light ray with wavelength 486 nm) of the aspherical collimating lens according to the present invention d: Center thickness of the aspherical collimating lens according to the present invention NA: Light source side of the aspherical collimating lens according to the present invention Number of apertures nF: Refractive rate in the F line (light ray with a wavelength of 486 nm) of the aspherical collimating lens according to the present invention.
R2': Radial curvature of the apex of the second surface when f is normalized as f = 1.0 (however, the sign means that the shape convex toward the light source is positive)
2.
The aspherical collimating lens according to claim 1, wherein the constituent material is glass and the following conditions are satisfied.
nF> 1.55
νd> 55
However,
νd: Abbe number of glass constituting the aspherical collimating lens according to the present invention.
3.
The aspherical collimating lens according to claim 2, wherein the aspherical collimating lens satisfies the following conditional expression.
T1> 0.8
T2> 0.95
However,
T1: Internal transmittance for light rays having a wavelength of 340 nm when the thickness of the constituent material is 10 mm T 2 : Internal transmittance for light rays having a wavelength of 400 nm when the thickness of the constituent material is 10 mm
【０００７】
【課題を解決するための手段】本発明では、光源から発する光束をコリメートする、 正の屈折力を持つ両凸形状の単レンズであって、前記光源側から順に第１面が球面、第 ２面が非球面で構成され、以下の条件式（１）乃至（４）を満足することを特徴とする 非球面コリメートレンズを構成することにより、課題の解決を図るものである。
（１） ｜R２｜＜f＜｜R１｜
（２）１．５＜f／d＜２．５
（３） NA＞０．４５
（４） ２．４８＜nF／｜R２'｜＜２．５２
但し、
R１：第１面の曲率半径（但し符号は光源側に凸の形状を正とする）
R２：第２面の頂点曲率半径（但し符号は光源側に凸の形状を正とする）
ｆ：本発明にかかる非球面コリメートレンズのＦ線（波長４８６ｎｍの光線）におけ る焦点距離
ｄ：本発明に係る非球面コリメートレンズの中心厚
ＮＡ：本発明にかかる非球面コリメートレンズの光源側の開口数
ｎＦ：本発明にかかる非球面コリメートレンズのＦ線（波長４８６ｎｍの光線）に おける屈折率
R２'：前記ｆをｆ＝１．０と規格化した時の第２面の頂点曲率半径（但し符号は光源 側に凸の形状を正とする）
0007
According to the present invention, a biconvex single lens having a positive refractive power that collimates a light beam emitted from a light source, and the first surface is a spherical surface and a second surface is in order from the light source side. The problem is solved by constructing an aspherical collimating lens characterized in that the surface is formed of an aspherical surface and the following conditional equations (1) to (4) are satisfied.
(1) | R2 | <f << R1 |
(2) 1.5 <f / d <2.5
(3) NA> 0.45
(4) 2.48 <nF / | R2' | <2.52
However,
R1: Radius of curvature of the first surface (however, the sign means that the shape convex toward the light source is positive)
R2: Radius of curvature of the apex of the second surface (however, the sign means that the shape convex toward the light source is positive)
f: Focus distance at F line (light ray with wavelength 486 nm) of the aspherical collimating lens according to the present invention d: Center thickness of the aspherical collimating lens according to the present invention NA: Light source side of the aspherical collimating lens according to the present invention Number of apertures nF: Refractive rate in the F line (light ray with a wavelength of 486 nm) of the aspherical collimating lens according to the present invention.
R2': The radius of curvature of the apex of the second surface when f is normalized to f = 1.0 (however, the sign means that the shape convex toward the light source is positive).
【００１３】
【実施例】図１は本発明の実施例の構成を示す断面図である。ここで、ｄ0は本発明の 非球面コリメートレンズＬと、光源Ｓとの距離を表す。以下に各数値実施例のレンズデ ータを示す。本発明は、光源側から数えて第２面が非球面であり、その形状は、光軸上 の頂点を原点とし、ｋを円錐定数、ｘ軸を光軸。ｙ軸を光軸に垂直な直線としたとき、
ｘ＝Ｃ・ｙ＊＊２／（１−ｋ・Ｃ＊＊２・ｙ＊＊２）＊＊０．５＋Ｃ２・ｙ＊＊２＋Ｃ ４・ｙ＊＊４＋Ｃ６・＊＊６＋Ｃ８・ｙ＊＊８＋Ｃ１０・ｙ＊＊１０
Ｃ＝１／Ｒ２
（式中及び以下全て、ａ＊＊ｂの表記は、ａのｂ乗を表すものとする）で表される。ま た、本発明の焦点距離は、光源として使用する水銀ランプの大きさや使用する装置全体 の大きさを考慮し、１８〜２５ｍｍ程度が望ましい。ただし、各実施例の諸元は全て焦 点距離を１ｍｍに規格化したときの値である。
[実施例１の諸元]
ｆ＝１．０mm
ＮＡ＝０．５７
ｎＦ＝１．５９６０２
νｄ＝６９
Ｒ１＝６．１６３７
ｄ＝０．５２５
Ｒ２＝−０．６３８８
Ｒ２´＝−０．６３８８
ｋ＝０
Ｃ２＝０
Ｃ４＝−１．７６７２３×１０＊＊−１
Ｃ６＝−４．３９５０８×１０＊＊−３
Ｃ８＝１．２６９５９×１０＊＊−１
Ｃ１０＝５．９０５１５×１０＊＊−２
Ｔ３４０＝０．８８
Ｔ４００＝０．９９
ｆ／ｄ＝１．９０５
ｎＦ／｜Ｒ２´｜＝２．４９８
[実施例２の諸元]
ｆ＝１．０mm
ＮＡ＝０．５７
ｎＦ＝１．５７４６４
νｄ＝７１．２
Ｒ１＝４．６３８７
ｄ＝０．５５０
Ｒ２＝−０．６２７５
Ｒ２´＝−０．６２７５
ｋ＝０
Ｃ２＝０
Ｃ４＝−１．７８２９７×１０＊＊−１
Ｃ６＝−４．４２３１８×１０＊＊−３
Ｃ８＝１．８７７３１×１０＊＊−１
Ｃ１０＝５．０６１３５×１０＊＊−２
Ｔ３４０＝０．８８
Ｔ４００＝０．９９
ｆ／ｄ＝１．８１８
ｎＦ／｜Ｒ２´｜＝２．５０９
[実施例３の諸元]
ｆ＝１．０mm
ＮＡ＝０．５７
ｎＦ＝１．５８９９５
νｄ＝５９．５
Ｒ１＝５．８２２７
ｄ＝０．５２５
Ｒ２＝−０．６３４５
Ｒ２´＝−０．６３４５
ｋ＝０
Ｃ２＝０
Ｃ４＝−１．７８６１９×１０＊＊−１
Ｃ６＝−７．５７５３４×１０＊＊−３
Ｃ８＝１．５３２１７５×１０＊＊−１
Ｃ１０＝４．０６９００×１０＊＊−２
Ｔ３４０＝０．８４
Ｔ４００＝０．９９
ｆ／ｄ＝１．９０５
ｎＦ／｜Ｒ２´｜＝２．５０６
さらに、図３乃至図５に、実施例１乃至実施例３の収差図を示す。これらの収差図は、 本発明の実施例の性能を明確に示すために、第２面側から平行光線を入射し、光源側に 結像させた時の収差を示している。また、各図において、非点収差図におけるｍはメリ ディオナル像面、ｓはサジタル像面を表す。さらに、球面収差図において、Ｈは軸上に 入射する平行光束の最大高さを、ＦＮはＦナンバーを表し、コマ収差図において、Ａは 画角を、Ｙは光源側の像高を表す。
0013
[Example] FIG. 1 is a cross-sectional view showing the configuration of an embodiment of the present invention. Here, d0 represents the distance between the aspherical collimating lens L of the present invention and the light source S. The lens data of each numerical example is shown below. In the present invention, the second surface is an aspherical surface counting from the light source side, and its shape is such that the apex on the optical axis is the origin, k is a conical constant, and the x-axis is the optical axis. When the y-axis is a straight line perpendicular to the optical axis
x = C ・ y ** 2 / (1-k ・ C ** 2 ・ y ** 2) ** 0.5 + C2 ・ y ** 2 + C 4 ・ y ** 4 + C6 ・ ** 6 + C8 ・ y ** 8 + C10・ Y ** 10
C = 1 / R2
(In the formula and all below, the notation of a ** b shall represent a to the b-th power). Further, the focal length of the present invention is preferably about 18 to 25 mm in consideration of the size of the mercury lamp used as a light source and the size of the entire device used. However, the specifications of each embodiment are the values when the focusing distance is standardized to 1 mm.
[Specifications of Example 1]
f = 1.0mm
NA = 0.57
nF = 1.59602
νd = 69
R1 = 6.1637
d = 0.525
R2 = -0.6388
R2'= -0.6388
k = 0
C2 = 0
C4 = -1.77623 × 10 ** -1
C6 = -4.39508 × 10 ** -3
C8 = 1.26959 × 10 ** -1
C10 = 5.90515 × 10 **-2
T340 = 0.88
T400 = 0.99
f / d = 1.905
nF / | R2' | = 2.498
[Specifications of Example 2]
f = 1.0mm
NA = 0.57
nF = 1.57464
νd = 71.2
R1 = 4.6387
d = 0.550
R2 = -0.6275
R2'= -0.6275
k = 0
C2 = 0
C4 = -1.78297 × 10 ** -1
C6 = -4.42318 × 10 ** -3
C8 = 1.87731 × 10 ** -1
C10 = 5.06135 × 10 **-2
T340 = 0.88
T400 = 0.99
f / d = 1.818
nF / | R2' | = 2.509
[Specifications of Example 3]
f = 1.0mm
NA = 0.57
nF = 1.58995
νd = 59.5
R1 = 5.8227
d = 0.525
R2 = -0.6345
R2'= -0.6345
k = 0
C2 = 0
C4 = -1.78619 × 10 ** -1
C6 = -7.57534 × 10 ** -3
C8 = 1.532175 x 10 ** -1
C10 = 4.06900 × 10 **-2
T340 = 0.84
T400 = 0.99
f / d = 1.905
nF / | R2' | = 2.506
Further, FIGS. 3 to 5 show aberration diagrams of Examples 1 to 3. These aberration diagrams show the aberrations when parallel rays are incident from the second surface side and imaged on the light source side in order to clearly show the performance of the embodiment of the present invention. Further, in each figure, m in the astigmatism diagram represents a meridional image plane, and s represents a sagittal image plane. Further, in the spherical aberration diagram, H represents the maximum height of the parallel light flux incident on the axis, FN represents the F number, and in the coma aberration diagram, A represents the angle of view and Y represents the image height on the light source side.