JPS61261238A - Production of lens having refractive index distribution in axial direction - Google Patents

Production of lens having refractive index distribution in axial direction

Info

Publication number
JPS61261238A
JPS61261238A JP9963685A JP9963685A JPS61261238A JP S61261238 A JPS61261238 A JP S61261238A JP 9963685 A JP9963685 A JP 9963685A JP 9963685 A JP9963685 A JP 9963685A JP S61261238 A JPS61261238 A JP S61261238A
Authority
JP
Japan
Prior art keywords
refractive index
lens
silver ions
glass plate
index distribution
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.)
Pending
Application number
JP9963685A
Other languages
Japanese (ja)
Inventor
Yoshiyuki Asahara
浅原 慶之
Hiroyuki Sakai
裕之 坂井
Shigeaki Omi
成明 近江
Shin Nakayama
伸 中山
Yoshitaka Yoneda
嘉隆 米田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hoya Corp
Original Assignee
Hoya Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hoya Corp filed Critical Hoya Corp
Priority to JP9963685A priority Critical patent/JPS61261238A/en
Publication of JPS61261238A publication Critical patent/JPS61261238A/en
Pending legal-status Critical Current

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  • Lenses (AREA)
  • Surface Treatment Of Glass (AREA)

Abstract

PURPOSE:To obtain the titled lens, safely and readily by bringing a medium containing silver ions into contact with the surface of a plate phosphate glass material, and diffusing and introducing the silver ions thereinto by the ion exchange to form a refractive index distribution in the thickness direction of the flat glass. CONSTITUTION:A medium containing silver ions, e.g. a mixed molten salt of silver nitrate and potassium nitrate, is brought into contact with at least one side of a plate phosphate glass material, and the silver ions are diffued and introduced into the flat glass by ion exchange and form the concentration distribution of the silver ions. Thus, the refractive index gradient is formed in the thickness direction from the surface to the interior thereof. The part having the desired refractive index distribution is then cut out of the flat glass and the direction of the refractive index gradient is made in agreement with the optical axis to carry out grinding. Thus, the aimed lens having a great refractive index in the axial direction can be readily produced without using a diffusing cation having strong toxicity, e.g. thallium.

Description

【発明の詳細な説明】 [産業上の利用分野] 本発明は、軸方向に屈折率分布を有する低収差のレンズ
の製造法に関する。
DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a low-aberration lens having a refractive index distribution in the axial direction.

[従来の技術] 従来、良く知られているように、均質な媒体で作製した
球面レンズには、第3A図、第3B図に示すようにレン
ズ1の周辺部を通る光線はど焦点距離が短かくなるとい
う、いわゆる球面収差を生ずる。これを防ぐ方法として
、レンズを組合せたり、非球面レンズとする方法もある
が、第4図に示すように光軸方向に屈折率分布を有する
媒質によってレンズ4を作って、これを補正することが
可能なことは良く知られている(註1)。ここで軸上屈
折率分布の理想的な分布は、 n−n(1+αZ)+ ・・・・・・・・・・・・(1
)と云われているか゛(註1)、これが直線的な屈折率
分布 n諺no+αZ     ・・・・・・・・・・・・(
21に近い分布であっても充分、球面収差を減する効果
はある(註2)。
[Prior Art] As is well known, in a spherical lens made of a homogeneous medium, the focal length of a ray passing through the periphery of the lens 1 is as shown in FIGS. 3A and 3B. This results in so-called spherical aberration, which is called shortening. There are ways to prevent this by combining lenses or using an aspherical lens, but as shown in Figure 4, it is possible to correct this by making the lens 4 from a medium that has a refractive index distribution in the optical axis direction. It is well known that this is possible (Note 1). Here, the ideal distribution of the axial refractive index distribution is nn(1+αZ)+ ・・・・・・・・・・・・(1
) (Note 1) This is a linear refractive index distribution n+αZ ・・・・・・・・・・・・・・・(
Even a distribution close to 21 is sufficiently effective in reducing spherical aberration (Note 2).

註1:イー・ダブリュー・マーチヤント“グラジェント
 インデックス オプチックス”アカデミツク プレス
、ニューヨーク [E、W、Harchand ”Gradient  
Index  0ptics  ”Academic 
 Press New Work  ]  (1978
)P106註2:飯塚啓吾゛″現代光工学の基礎″オー
ム社(1980)P131 Sの様な軸上屈折率分布型レンズの製造法としては、従
来例えば第5図に示すように平行平面をもつ母材ガラス
板3をタリウム(TIl)、リチウム(Li)、セシウ
ム(C8)のうちから選んだ陽イオンを含む溶融塩2中
に浸漬し、イオン交換により、前記イオンをガラス板3
内に拡散させ、陽イオンの濃度分布を形成することによ
り、ガラス板吊に表面から内部に向けて厚み方向に屈折
率分布を形成し、この母材ガラスから第6図に示す如く
必要な屈折率分布を有する部分(点線で囲まれた部分5
)を切り出し、研磨加工してレンズ4を作る方法がある
Note 1: E. W. Marchant “Gradient Index Optics” Academic Press, New York [E. W. Harchand “Gradient”
Index 0ptics ”Academic
Press New Work] (1978
) P106 Note 2: Keigo Iizuka, "Fundamentals of Modern Optical Engineering" Ohmsha (1980) P131 As for the manufacturing method of an axial gradient index lens such as S, conventionally, parallel planes were fabricated as shown in Fig. 5. A base material glass plate 3 with a base material 3 is immersed in a molten salt 2 containing cations selected from thallium (TIl), lithium (Li), and cesium (C8), and the ions are transferred to the glass plate 3 by ion exchange.
By diffusing the cations inside and forming a concentration distribution of cations, a refractive index distribution is formed in the thickness direction from the surface to the inside of the glass plate, and the necessary refraction is obtained from this base material glass as shown in Figure 6. The part with a rate distribution (the part surrounded by the dotted line 5
) is cut out and polished to make the lens 4.

[発明が解決しようとする問題点] 上記タリウム、リチウム、セシウムのうちから選んだ陽
イオンを含む溶融塩2に浸漬する方法を用いることによ
って(1)あるいは(2式に近似し得る屈折率分布を得
ることはできるが、拡散陽イオンとしてタリウム(Tf
>は、毒性が強くその取扱いが難かしいという問題点が
あり、またリチウム(Li)やセシウム(Os)は毒性
はないものの、TIlはどの大きな屈折率差が得られな
いという欠点がある。さらに拡散速度がいづれの陽イオ
ンも小さいため厚いレンズを作る場合、難点があった。
[Problems to be Solved by the Invention] By using the method of immersion in the molten salt 2 containing cations selected from the above thallium, lithium, and cesium, the refractive index distribution can be approximated by equation (1) or (2). However, thallium (Tf) can be obtained as a diffused cation.
> has the problem of being highly toxic and difficult to handle, and although lithium (Li) and cesium (Os) are not toxic, TIl has the disadvantage of not being able to obtain a large refractive index difference. Furthermore, since the diffusion rate of all cations was low, it was difficult to make thick lenses.

そこで本発明は毒性がなく、大きな屈折率差のある軸方
向屈折率分布型のレンズを容易に製造することを目的と
している。
Therefore, an object of the present invention is to easily manufacture an axially graded refractive index lens that is nontoxic and has a large refractive index difference.

[問題点を解決するための手段] 上記目的を達成するため本発明は、板状のリン酸塩ガラ
ス体の少なくとも片面に銀イオンを含む媒体を接触させ
、イオン交換により前記銀イオンをガラス板内に拡散移
入させて銀イオンの濃度分布を形成することにより、ガ
ラス板中の表面から内部に向って厚み方向に屈折率勾配
を形成し、このガラス板より所望の屈折率勾配を有する
部分を切り出し、屈折率勾配の方向を光軸と一致させて
研磨加工することを特徴とするものである。
[Means for Solving the Problems] In order to achieve the above object, the present invention brings a medium containing silver ions into contact with at least one side of a plate-shaped phosphate glass body, and transfers the silver ions to the glass plate by ion exchange. By diffusing into the glass plate to form a concentration distribution of silver ions, a refractive index gradient is formed in the thickness direction from the surface to the inside of the glass plate, and a portion having a desired refractive index gradient is formed from this glass plate. It is characterized in that it is cut out and polished with the direction of the refractive index gradient aligned with the optical axis.

[発明の効果] 本発明は溶融塩法によって屈折率勾配のあるレンズを作
るに当り、高屈折率をもたらす陽イオンとして銀イオン
を用いたものであるから、タリウムよりも拡散が速く、
かつ毒性が弱く、またリチウムやセシウムに比べて、高
屈折率差が得られる。
[Effects of the Invention] The present invention uses silver ions as cations that provide a high refractive index when producing lenses with a refractive index gradient by the molten salt method, so they diffuse faster than thallium.
It is also less toxic and provides a higher refractive index difference than lithium or cesium.

また基板ガラス材料としてリン酸ガラスを用いたから銀
イオンを多量に導入してもコロイド状の銀による着色が
生じない。
Furthermore, since phosphate glass is used as the substrate glass material, coloring due to colloidal silver does not occur even if a large amount of silver ions are introduced.

[実施例] 以下、本発明を実施例に基づき説明する。[Example] Hereinafter, the present invention will be explained based on examples.

カ[11 ガラス基板として重量%でP2O548%、Na202
9%、Nt)205 15%、3価の酸化物8%よりな
る組成の厚さ5−―、幅20m−のガラスを用い、温度
350℃で70時間、AQN03 40%、K N O
36G% (重量%)の混合溶融塩中で処理した。この
ガラス板の表面附近の屈折率分布は第54図に示すよう
なものであった。この板より第1図の点線で示す位置で
゛ガラスを切り出し、直径1c■厚さ1■、曲率1.3
cmのレンズを作製すると、縦収差は第2図中の曲線す
のようになり、軸上屈折率分布をもたない従来の球面レ
ンズが第2図中曲線aのような球面収差をもつものに著
しく改善できる。
[11 As a glass substrate, P2O548%, Na202
AQN03 40%, K NO
Processed in 36G% (wt%) mixed molten salt. The refractive index distribution near the surface of this glass plate was as shown in FIG. A piece of glass was cut out from this plate at the position indicated by the dotted line in Figure 1, with a diameter of 1 cm x thickness of 1 cm, and a curvature of 1.3 cm.
When a lens with a diameter of cm is manufactured, the longitudinal aberration becomes as shown by the curve in Figure 2, and a conventional spherical lens without an axial refractive index distribution has a spherical aberration as shown in the curve a in Figure 2. can be significantly improved.

実施例2 基板ガラスとして重量%でP2O548%、N8202
0X、 K209X %T i 02 15Xを含むガ
ラス板を実施例1と同様の溶融塩を用い、350℃で9
5時間処理し、これより切り出した直径1.10−1厚
さ0.85am 、曲率1.82cmのレンズは、第2
図の曲線Cに示すように球面収差は著しく改良されてい
た。
Example 2 P2O548%, N8202 in weight% as substrate glass
A glass plate containing 0
A lens with a diameter of 1.10-1, a thickness of 0.85 am, and a curvature of 1.82 cm was cut out after processing for 5 hours.
As shown by curve C in the figure, spherical aberration was significantly improved.

上記の実施例1.2のいづれの場合も銀イオンの導入に
よって通常珪酸塩や硼珪酸塩に生ずるコロイド状の銀に
よる褐色の着色は全く観察されなかった。
In any of the above Examples 1.2, no brown coloration due to colloidal silver, which normally occurs in silicates and borosilicates due to the introduction of silver ions, was observed.

【図面の簡単な説明】[Brief explanation of drawings]

第1図は本発明のガラス板の屈折率分布図、第2図は本
発明の軸上屈折率分布型レンズの収差特性線図、第3A
図は通常の球面レンズの球面収差を示す説明図、第3B
図は同じく縦収差線図、第4図は軸上屈折率分布による
球面収差の改良を示す説明図、第5図はイオン交換法に
よる軸上屈折率分布ガラスの製造工程の断面図、第6図
は屈折率分布をレンズの切出し位置を示す説明図である
。 出 願 人  ホーヤ株式会社 代  理  人   朝  倉  正  幸ffフ(m
m) fIL峨覆(cm) 第3A図 第3B図 第4図 第5図 第6図 手続補正書(自制 昭和60年 6月lr日
FIG. 1 is a refractive index distribution diagram of the glass plate of the present invention, FIG. 2 is an aberration characteristic diagram of the axial gradient index lens of the present invention, and FIG.
The figure is an explanatory diagram showing the spherical aberration of a normal spherical lens, No. 3B.
The figure is also a longitudinal aberration diagram, Figure 4 is an explanatory diagram showing improvement of spherical aberration by axial refractive index distribution, Figure 5 is a cross-sectional view of the manufacturing process of axial refractive index distribution glass by ion exchange method, and Figure 6 The figure is an explanatory diagram showing the refractive index distribution and the cutting position of the lens. Applicant: Hoya Co., Ltd. Representative: Tadashi Asakuraff(m)
m) fIL overturn (cm) Figure 3A Figure 3B Figure 4 Figure 5 Figure 6 Procedural amendment (Self-restraint Date of June 1985)

Claims (1)

【特許請求の範囲】[Claims] 1 板状のリン酸塩ガラス体の少なくとも片面にAg(
銀)イオンを含む媒体を接触させ、イオン交換により前
記イオンをガラス板内に拡散移入させて銀イオンの濃度
分布を形成することによりガラス板中に表面から内部に
向って厚み方向に屈折率勾配を形成し、このガラス板よ
り所望の屈折率勾配を有する部分を切り出し、屈折率勾
配の方向を光軸と一致させて研磨加工することを特徴と
する軸方向屈折率分布型のレンズの製造法。
1 Ag (
A refractive index gradient is created in the thickness direction from the surface to the inside of the glass plate by bringing a medium containing silver (silver) ions into contact with the glass plate and diffusing the ions into the glass plate through ion exchange to form a concentration distribution of silver ions. A method for manufacturing an axially distributed refractive index lens, comprising: forming a glass plate, cutting out a portion having a desired refractive index gradient from this glass plate, and polishing the glass plate so that the direction of the refractive index gradient coincides with the optical axis. .
JP9963685A 1985-05-13 1985-05-13 Production of lens having refractive index distribution in axial direction Pending JPS61261238A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9963685A JPS61261238A (en) 1985-05-13 1985-05-13 Production of lens having refractive index distribution in axial direction

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9963685A JPS61261238A (en) 1985-05-13 1985-05-13 Production of lens having refractive index distribution in axial direction

Publications (1)

Publication Number Publication Date
JPS61261238A true JPS61261238A (en) 1986-11-19

Family

ID=14252551

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9963685A Pending JPS61261238A (en) 1985-05-13 1985-05-13 Production of lens having refractive index distribution in axial direction

Country Status (1)

Country Link
JP (1) JPS61261238A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0918235A2 (en) * 1997-11-20 1999-05-26 Nippon Sheet Glass Co., Ltd. Axial refractive index distributed lens
EP1106586A1 (en) 1999-12-01 2001-06-13 Nippon Sheet Glass Co., Ltd. Graded index lens
JP2002311212A (en) * 2001-04-13 2002-10-23 Nippon Sheet Glass Co Ltd Working method for lens having distribution of refractive index in optical axis direction, lens having distribution of refractive index in optical axis direction produced by the method, and collimator using the lens

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58106504A (en) * 1981-12-18 1983-06-24 Nippon Sheet Glass Co Ltd Manufacture of refractive index distribution type transparent member
JPS58167452A (en) * 1982-03-29 1983-10-03 Nippon Sheet Glass Co Ltd Preparation of material wherein very small lenses are arranged
JPS58167451A (en) * 1982-03-25 1983-10-03 Seiko Epson Corp Preparation of optical element
JPS5964547A (en) * 1982-10-02 1984-04-12 Nippon Sheet Glass Co Ltd Preparation of lens having refractive index distribution in axial direction

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58106504A (en) * 1981-12-18 1983-06-24 Nippon Sheet Glass Co Ltd Manufacture of refractive index distribution type transparent member
JPS58167451A (en) * 1982-03-25 1983-10-03 Seiko Epson Corp Preparation of optical element
JPS58167452A (en) * 1982-03-29 1983-10-03 Nippon Sheet Glass Co Ltd Preparation of material wherein very small lenses are arranged
JPS5964547A (en) * 1982-10-02 1984-04-12 Nippon Sheet Glass Co Ltd Preparation of lens having refractive index distribution in axial direction

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0918235A2 (en) * 1997-11-20 1999-05-26 Nippon Sheet Glass Co., Ltd. Axial refractive index distributed lens
EP0918235A3 (en) * 1997-11-20 1999-06-16 Nippon Sheet Glass Co., Ltd. Axial refractive index distributed lens
US6066273A (en) * 1997-11-20 2000-05-23 Nippon Sheet Glass Co., Ltd. Axial refractive index distributed lens
EP1106586A1 (en) 1999-12-01 2001-06-13 Nippon Sheet Glass Co., Ltd. Graded index lens
JP2002311212A (en) * 2001-04-13 2002-10-23 Nippon Sheet Glass Co Ltd Working method for lens having distribution of refractive index in optical axis direction, lens having distribution of refractive index in optical axis direction produced by the method, and collimator using the lens

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