JPH0575089B2 - - Google Patents
Info
- Publication number
- JPH0575089B2 JPH0575089B2 JP60278210A JP27821085A JPH0575089B2 JP H0575089 B2 JPH0575089 B2 JP H0575089B2 JP 60278210 A JP60278210 A JP 60278210A JP 27821085 A JP27821085 A JP 27821085A JP H0575089 B2 JPH0575089 B2 JP H0575089B2
- Authority
- JP
- Japan
- Prior art keywords
- microscope objective
- lens
- cover glass
- observed
- objective lens
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000006059 cover glass Substances 0.000 claims description 18
- 230000005499 meniscus Effects 0.000 claims description 2
- 230000004075 alteration Effects 0.000 description 20
- 238000010586 diagram Methods 0.000 description 5
- 238000003384 imaging method Methods 0.000 description 5
- 230000003287 optical effect Effects 0.000 description 5
- 201000009310 astigmatism Diseases 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 230000004907 flux Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/0025—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for optical correction, e.g. distorsion, aberration
- G02B27/0068—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for optical correction, e.g. distorsion, aberration having means for controlling the degree of correction, e.g. using phase modulators, movable elements
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Lenses (AREA)
Description
産業上の利用分野
本発明は顕微鏡対物レンズに関するものであ
り、特に金属顕微鏡を、工業分野においてカバー
ガラスを有する物体に適用するための補正レンズ
に関するものである。
従来の技術
近年ビデオカメラ用撮像デバイスは撮像管から
固体撮像素子に替わりつつある。カラー固体撮像
素子の製造においては、ガラス基板下面に形成し
た色分解フイルターを固体撮像素子上に接合する
工程がある。この工程においては、フイルターと
固体撮像素子を精密に位置合わせするために金属
顕微鏡が使用されている。
以下図面を参照しながら、上述した従来の金属
顕微鏡対物レンズの一例について説明する。
第３図〜第６図は特開昭59−174812号公報に示
されたような従来の長作動距離金属顕微鏡対物レ
ンズの構成と収差を示すものである。第３図にお
いて、１は物体であり、２は顕微鏡対物レンズ、
３は結像レンズである。第４図は同レンズの収差
図であり、球面収差、非点収差、歪曲収差は良好
な値を示している。
発明が解決しようとする問題点
しかしながら、このような顕微鏡対物レンズ
を、第５図に示す如く物体４の上に厚サ0.5mm、
屈折率1.46のカバーガラス５を有する固体撮像素
子用色フイルターのような被観察物に使用した場
合には、第６図の収差図に示す如く、非点収差は
約２倍となり、歪曲収差はほぼ同じに留まるのに
対し、球面収差が約75倍も大きくなり、全体とし
て解像度とコントラストが低下し、色の再現性も
低下するという問題点があつた。もちろん、この
ようなカバーガラスを有する被観察物に対して
は、専用対物レンズを設計製作すれば良いのであ
るが、専用対物レンズの設計製作は多大の費用と
期間と高度の技術を要するという問題点があつ
た。
本発明は上記問題点に鑑み、既製の金属顕微鏡
対物レンズの前面に取付けて、カバーガラスによ
つて生ずる球面収差を実用上差しつかえない程度
に補正する顕微鏡対物補正レンズを提供するもの
である。
問題点を解決するための手段
上記問題点を解決するために本発明の顕微鏡対
物補正レンズは、顕微鏡対物レンズと、その顕微
鏡対物レンズに対向する側にカバーガラスを備え
た被観察物体との間に配され、前記被観察物体に
対して、凹面を向けた、１群構成レンズメニスカ
スレンズによつて、カバーガラスにより生ずる球
面収差を補正するものであり、次の条件(a)及び(b)
を満足するようにしたものである。
(a) −10.68×0.781.37nt×ｆ＜r4＜−10.0×
0.781.37nt×ｆ
(b) (Q)fc(Q)＞450f
但し、ｎは被観察物体のカバーガラスの屈折
率、ｔは被観察物体のカバーガラスの厚さ（mm）、
ｆは顕微鏡対物レンズの焦点距離（mm）、r4は顕
微鏡対物補正レンズの物体側光線入射方向第１面
の曲率半径（mm）、fcは顕微鏡対物補正レンズの
焦点距離（mm）である。
作 用
本発明は上記した構成によつて、顕微鏡対物補
正レンズの無い場合、カバーガラスを有する被観
察物体から出た光軸から離れた光線がカバーガラ
スによつて、光線束が小さくなり、第６図の球面
収差曲線に示す如く、球面収差がカバーガラスの
ないときに比べ著しく正の方向へ倒れていくのに
対し、補正レンズを用いてカバーガラスで縮小さ
れた光線束を元の大きさと同じ程度に戻すことに
よつて、正の方向に倒れていた球面収差を負の方
向に補正するものである。そのために本発明の顕
微鏡対物補正レンズは前記の２つの条件(a)，(b)を
満足するようにしてある。
条件(a)において、r4が上限の値を超えると球面
収差が補正不足となり、それをカバーするために
補正レンズと対物レンズの間隔を広げなければな
らず、作動距離が小さくなり過ぎてしまい、r4が
下限の値以下になると球面収差が過小になり、そ
れをカバーするために補正レンズと対物レンズの
間隔を小さくしなければならなくなり、レンズ同
志がぶつかつてしまうことになる。
条件(b)は、球面収差補正過剰の限界において、
fcの絶対値が450f以下になると、全系の焦点距離
が大幅に変化してしまい、倍率が著しく変化す
る。
実施例
以下本発明の一実施例の顕微鏡対物補正レンズ
について図面を参照しながら説明する。
第１図において、１１は被観察物体、１２はカ
バーガラス、１３は本発明の顕微鏡対物補正レン
ズ、１４は前記従来例において説明した顕微鏡対
物レンズ、１５は結像レンズであり、像面r30（図
示せず）に結像する。
次に実施例の詳細数値について記す。
補正後の全光学系の焦点距離4.88mm、被観察物
体側開口比N.A.＝0.5倍、倍率×50、作動距離
9.11mm、顕微鏡対物補正レンズの焦点距離fc＝
3369.05mmである。
その他の詳細な値は、下表に示す通りである。
なお、曲率半径、厚さの単位はmmである。ｎ＝
1.46、ｔ＝0.5mm、ｆ＝5.00mm、fc＝3369.05mm、r4
＝−41.46mm、0.781.37nt×ｆ＝3.901、450×ｆ＝
2250mm
INDUSTRIAL APPLICATION FIELD The present invention relates to a microscope objective lens, and more particularly to a correction lens for applying a metallurgical microscope to an object having a cover glass in the industrial field. 2. Description of the Related Art In recent years, imaging devices for video cameras are replacing image pickup tubes with solid-state imaging devices. In manufacturing a color solid-state image sensor, there is a step of bonding a color separation filter formed on the lower surface of a glass substrate onto the solid-state image sensor. In this step, a metallurgical microscope is used to precisely align the filter and the solid-state image sensor. An example of the above-mentioned conventional metallurgical microscope objective lens will be described below with reference to the drawings. 3 to 6 show the structure and aberrations of a conventional long working distance metallurgical microscope objective lens as disclosed in Japanese Unexamined Patent Publication No. 59-174812. In Fig. 3, 1 is an object, 2 is a microscope objective lens,
3 is an imaging lens. FIG. 4 is an aberration diagram of the same lens, showing good values for spherical aberration, astigmatism, and distortion. Problems to be Solved by the Invention However, such a microscope objective lens is placed on an object 4 with a thickness of 0.5 mm as shown in FIG.
When used in an object to be observed such as a color filter for a solid-state image sensor having a cover glass 5 with a refractive index of 1.46, the astigmatism is approximately doubled and the distortion is However, the problem was that the spherical aberration was approximately 75 times larger, resulting in lower overall resolution and contrast, as well as lower color reproducibility. Of course, it would be possible to design and manufacture a dedicated objective lens for an object to be observed that has such a cover glass, but the problem is that designing and manufacturing a dedicated objective lens requires a great deal of cost, time, and advanced technology. The point was hot. In view of the above problems, the present invention provides a microscope objective correction lens that is attached to the front surface of a ready-made metallurgical microscope objective lens and corrects the spherical aberration caused by the cover glass to a practically acceptable level. Means for Solving the Problems In order to solve the above problems, the microscope objective correction lens of the present invention is provided between a microscope objective lens and an object to be observed, which is provided with a cover glass on the side opposite to the microscope objective lens. The spherical aberration caused by the cover glass is corrected by a single-group meniscus lens with a concave surface facing the object to be observed, and the following conditions (a) and (b) are met.
It is designed to satisfy the following. (a) −10.68×0.78 1.37nt ×f<r 4 <−10.0×
0.78 1.37nt ×f (b) (Q)f c (Q)＞450f However, n is the refractive index of the cover glass of the object to be observed, t is the thickness (mm) of the cover glass of the object to be observed,
f is the focal length of the microscope objective lens (mm), r4 is the radius of curvature of the first surface of the microscope objective correction lens in the direction of incidence of the rays on the object side (mm), and f c is the focal length of the microscope objective correction lens (mm) . Effects The present invention has the above-described configuration, and when there is no microscope objective correction lens, the cover glass reduces the beam flux of light rays that are far from the optical axis and is emitted from an object to be observed that has a cover glass. As shown in the spherical aberration curve in Figure 6, the spherical aberration is significantly tilted in the positive direction compared to when there is no cover glass. By restoring the aberrations to the same degree, the spherical aberration, which had been tilted in the positive direction, is corrected in the negative direction. For this purpose, the microscope objective correction lens of the present invention is designed to satisfy the above two conditions (a) and (b). In condition (a), if r 4 exceeds the upper limit value, spherical aberration will be insufficiently corrected, and in order to compensate for this, the distance between the correction lens and the objective lens must be widened, and the working distance will become too small. , r 4 becomes less than the lower limit value, the spherical aberration becomes too small, and in order to compensate for it, the distance between the correction lens and the objective lens must be reduced, and the lenses will collide with each other. Condition (b) is, at the limit of overcorrection of spherical aberration,
When the absolute value of f c becomes less than 450 f, the focal length of the entire system changes significantly, and the magnification changes significantly. Embodiment A microscope objective correction lens according to an embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 11 is an object to be observed, 12 is a cover glass, 13 is the microscope objective correction lens of the present invention, 14 is the microscope objective lens explained in the conventional example, and 15 is an imaging lens, and the image plane r 30 (not shown). Next, detailed numerical values of the examples will be described. Focal length of the entire optical system after correction: 4.88mm, aperture ratio on the object side NA = 0.5x, magnification x 50, working distance
9.11mm, focal length of microscope objective correction lens f c =
It is 3369.05mm. Other detailed values are shown in the table below. Note that the radius of curvature and thickness are in mm. n=
1.46, t=0.5mm, f=5.00mm, f c =3369.05mm, r 4
=-41.46mm, 0.78 1.37nt ×f=3.901, 450×f=
2250mm
【表】【table】
【表】
上記の実施例による収差曲線を第２図に示す。
第６図に示した従来例に対し、球面収差は約1/30
に減少し、非点収差、歪曲収差は同等である。第
４図に示した顕微鏡対物レンズの単体の性能に対
しても、球面収差と非点収差が約２倍になるだけ
であり、歪曲収差については同等である。なお顕
微鏡対物補正レンズの顕微鏡対物レンズ前面への
取付けについては、顕微鏡対物レンズ鏡筒の外周
に金具で着脱自在に取付ける。金属表面を観察す
る時は、顕微鏡対物補正レンズを外して使用す
る。また対物補正レンズは顕微鏡対物レンズの前
面に取付ける形式なのでN.A.と作動距離の似た
他の対物レンズに対しても使用することができ
る。
発明の効果
以上のように本発明は、顕微鏡対物レンズの前
面に１群のレンズを取付けることにより、カバー
ガラスを有する被観察物体の観察時の球面収差を
実用上差しつかえない程度に減少させて、解像度
とコントラスト、色再現性を向上させ、専用対物
レンズ全体を設計製作するよりも安価で容易に製
作することができ、また着脱自在の金具で顕微鏡
対物レンズに取付けることにより、通常の金属顕
微鏡としても使用できるという効果を有する。[Table] FIG. 2 shows aberration curves according to the above embodiment.
Spherical aberration is approximately 1/30 compared to the conventional example shown in Figure 6.
The astigmatism and distortion are the same. Compared to the performance of the single microscope objective lens shown in FIG. 4, the spherical aberration and astigmatism are only about twice as large, and the distortion is the same. When attaching the microscope objective correction lens to the front surface of the microscope objective lens, it is detachably attached to the outer periphery of the microscope objective lens barrel using a metal fitting. When observing metal surfaces, remove the objective correction lens from the microscope. Furthermore, since the objective correction lens is attached to the front of the microscope objective, it can also be used for other objectives with similar NA and working distance. Effects of the Invention As described above, the present invention reduces spherical aberration during observation of an observed object having a cover glass to a practically acceptable level by attaching a group of lenses to the front surface of a microscope objective lens. , improves resolution, contrast, and color reproducibility, and can be manufactured more cheaply and easily than designing and manufacturing an entire dedicated objective lens.In addition, by attaching it to the microscope objective lens with a removable metal fitting, it can be easily manufactured using an ordinary metallurgical microscope. It has the effect of being able to be used as a
第１図は本発明の実施例の全光学系の断面図、
第２図は同実施例の収差曲線図、第３図は従来の
顕微鏡対物レンズを金属表面の観察に用いる場合
の光学系断面図、第４図は同収差曲線図、第５図
は従来の顕微鏡対物レンズをカバーガラスを有す
る物体の観察に用いる場合の光学系断面図、第６
図は同収差曲線図である。
１１……被観察物体、１２……カバーガラス、
１３……顕微鏡対物補正レンズ、１４……顕微鏡
対物レンズ、１５……結像レンズ。
FIG. 1 is a cross-sectional view of the entire optical system according to the embodiment of the present invention.
Fig. 2 is an aberration curve diagram of the same example, Fig. 3 is a sectional view of the optical system when a conventional microscope objective lens is used for observing a metal surface, Fig. 4 is an aberration curve diagram of the same, and Fig. 5 is a diagram of the conventional microscope objective lens. 6th cross-sectional view of the optical system when using a microscope objective lens to observe an object with a cover glass
The figure is an aberration curve diagram. 11...Object to be observed, 12...Cover glass,
13... Microscope objective correction lens, 14... Microscope objective lens, 15... Imaging lens.
Claims (1)
に対向する側にカバーガラスを備えた被観察物体
との間に配され、前記被観察物体に対して、凹面
を向けたメニスカス形状の１群構成レンズであつ
て、次の条件(a)及び条件(b)を満足する顕微鏡対物
補正レンズ。 (a) −10.68×0.781.37nt×ｆ＜r4＜−10.0×
0.781.37nt×ｆ (b) (Q)fc(Q)＞450f 但し、ｎは被観察物体のカバーガラスの屈折
率、ｔは被観察物体のカバーガラスの厚さ（mm）、
ｆは顕微鏡対物レンズの焦点距離（mm）、r4は顕
微鏡対物補正レンズの物体側光線入射方向第１面
の曲率半径（mm）、fcは顕微鏡対物補正レンズの
焦点距離（mm）である。[Claims] 1. A meniscus shape disposed between a microscope objective lens and an object to be observed having a cover glass on the side facing the microscope objective lens, and having a concave surface facing the object to be observed. A microscope objective correction lens which is a one-group lens and satisfies the following conditions (a) and (b). (a) −10.68×0.78 1.37nt ×f<r 4 <−10.0×
0.78 1.37nt ×f (b) (Q)f c (Q)＞450f However, n is the refractive index of the cover glass of the object to be observed, t is the thickness (mm) of the cover glass of the object to be observed,
f is the focal length of the microscope objective lens (mm), r4 is the radius of curvature of the first surface of the microscope objective correction lens in the direction of incidence of the rays on the object side (mm), and f c is the focal length of the microscope objective correction lens (mm) .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60278210A JPS62136616A (en) | 1985-12-11 | 1985-12-11 | Microscope objective compensating lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60278210A JPS62136616A (en) | 1985-12-11 | 1985-12-11 | Microscope objective compensating lens |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62136616A JPS62136616A (en) | 1987-06-19 |
| JPH0575089B2 true JPH0575089B2 (en) | 1993-10-19 |
Family
ID=17594129
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60278210A Granted JPS62136616A (en) | 1985-12-11 | 1985-12-11 | Microscope objective compensating lens |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62136616A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05196873A (en) * | 1992-01-21 | 1993-08-06 | Mitsutoyo Corp | Microscope objective |
| JP5570171B2 (en) * | 2009-10-06 | 2014-08-13 | キヤノン株式会社 | Imaging device and surveillance camera |
-
1985
- 1985-12-11 JP JP60278210A patent/JPS62136616A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62136616A (en) | 1987-06-19 |
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