JPH0632631A - Optical glass for precision press - Google Patents

Optical glass for precision press

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Publication number
JPH0632631A
JPH0632631A JP19076392A JP19076392A JPH0632631A JP H0632631 A JPH0632631 A JP H0632631A JP 19076392 A JP19076392 A JP 19076392A JP 19076392 A JP19076392 A JP 19076392A JP H0632631 A JPH0632631 A JP H0632631A
Authority
JP
Japan
Prior art keywords
glass
optical
refractive index
optical glass
component
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.)
Granted
Application number
JP19076392A
Other languages
Japanese (ja)
Other versions
JP3122236B2 (en
Inventor
Nobuyoshi Baba
信義 馬場
Shinobu Nagahama
忍 永濱
Shigeto Sawanobori
成人 沢登
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.)
Sumita Optical Glass Inc
Original Assignee
Sumita Optical Glass Inc
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 Sumita Optical Glass Inc filed Critical Sumita Optical Glass Inc
Priority to JP04190763A priority Critical patent/JP3122236B2/en
Publication of JPH0632631A publication Critical patent/JPH0632631A/en
Application granted granted Critical
Publication of JP3122236B2 publication Critical patent/JP3122236B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Abstract

PURPOSE:To provide optical glass having low refractive index and high dispersion, moldable by precision press at a lower temperature <=620 deg.C, namely 30-50 deg.C higher than yield temperature (At). CONSTITUTION:Glass having a composition consisting of 10.0-50.0wt.% SiO2, 5.0-52.0wt.% GeO2, 4.0-25.0wt.% TiO2, 0-25.0wt.% Nb2O5 with the proviso that total amount of SiO2+GeO2 is 45.0-67.0wt.% and total amount of TiO2+Nb2O5 is 10.0-30.0wt.%, 1.0-5.0wt.% Li2O, 5.0-19.0wt.% N2O, 0-8.0wt.% K2O, 0-20wt.% CS2O with the proviso that total amount of Li2O+Na2O+K2O+CS2O is 8.0-32.0wt.%, 0-10.0wt.% ZnO, 0-8.0wt.% MgO, 0-6.0wt.% Al2O3, 0-1.0wt.% ZrO2 and 0-3.0wt.% TeO2.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、低温でプレス成形で
き、プレス成形後研削または研磨を必要としない精密プ
レス用光学ガラスに関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical glass for precision press which can be press-formed at a low temperature and does not require grinding or polishing after the press-forming.

【0002】[0002]

【従来の技術】従来同じような光学恒数を持つものとし
て、低屈折率高分散タイプ(nd=1.660以下、 ν
d=40.5以下) の酸化鉛を多量に含有した光学ガラ
スが存在する。またプレス成形用の光学ガラスとして、
燐酸塩系光学ガラス(特開昭60−122749号公
報、特開昭58−79839号公報、欧州特許第193
42号明細書、参照)フルオロ燐酸塩系光学ガラス(特
開昭56−59641号公報、特開昭58−21745
1号公報、参照)ホウ珪酸塩系光学ガラス(特開昭62
−123040号公報、参照)が知られている。
2. Description of the Related Art A low refractive index, high dispersion type (nd = 1.660 or less, ν
There is an optical glass containing a large amount of lead oxide (d = 40.5 or less). Also, as optical glass for press molding,
Phosphate-based optical glass (JP-A-60-122749, JP-A-58-79839, European Patent 193)
42, reference) Fluorophosphate optical glass (JP-A-56-59641, JP-A-58-21745)
No. 1, gazette) Borosilicate optical glass (JP-A-62-62)
-123040 gazette, reference) is known.

【0003】[0003]

【発明が解決しようとする課題】近年一眼レフカメラや
ビデオ一体型カメラなどの軽量、高性能化にともない、
これらの製品のレンズ部分の軽量化、高性能化のため
に、非球面レンズが用いられる様になってきた。非球面
レンズの採用によって、レンズ枚数の減少による軽量
化、また非球面化によって、レンズの球面収差の除去に
よる高性能化などがはかられてきている。しかし、従来
の研削研磨によるレンズの作製方法では、非球面化がか
なり困難であり、量産性が悪いので非常に高価なものと
なっている。このため現在では、精密加工した型材によ
る、研削研磨を必要としない精密プレス成形による作製
方法が用いられる様になってきている。しかしながら、
これまでに知られている精密プレス成形用の型材料は、
成形温度が高温になると材料の劣化が起こり、型の面精
度を保持することが困難になりプレスレンズの量産には
適さない。そのためプレスされるガラスは、可能な限り
低い温度で成形できるものが望ましい。すなわち、通常
行われる精密プレス成形は、ガラスの屈伏温度(At)
より、約30〜50℃高い温度で実施されている。した
がって、ガラスの屈伏温度(At)はできるだけ低いこ
とが望まれる。
With the recent trend toward lighter weight and higher performance of single-lens reflex cameras and video-integrated cameras,
In order to reduce the weight and improve the performance of the lens portion of these products, aspherical lenses have come to be used. By using an aspherical lens, weight reduction is achieved by reducing the number of lenses, and by asphericalization, high performance is achieved by removing spherical aberration of the lens. However, with the conventional method of manufacturing a lens by grinding and polishing, it is very difficult to form an aspherical surface, and mass productivity is poor, so that it is very expensive. For this reason, at present, a manufacturing method by precision press molding which does not require grinding and polishing using a precision processed mold material has come to be used. However,
The known mold materials for precision press molding are:
When the molding temperature becomes high, the material deteriorates and it becomes difficult to maintain the surface accuracy of the mold, which is not suitable for mass production of press lenses. Therefore, it is desirable that the glass to be pressed can be molded at a temperature as low as possible. That is, the precision press molding that is usually performed is the deformation temperature (At) of glass.
Therefore, it is carried out at a temperature about 30 to 50 ° C. higher. Therefore, the deformation temperature (At) of glass is desired to be as low as possible.

【0004】また、従来より存在する光学ガラスには、
ガラス成分として酸化鉛が10〜50%程度含まれてい
る。これらの光学ガラスを精密プレスに使用すると、型
材の酸化を防ぐために通常還元雰囲気で行われているた
め、その雰囲気によりガラス表面に存在する酸化鉛が還
元され、プレスレンズ表面に析出し、プレスするための
加熱により蒸発し、プレスレンズ表面に凹部を形成し、
蒸発した鉛が型材の表面に付着し凸部を形成することに
より、微小な凹凸が生じ、プレス成形されたレンズの面
精度が維持できないため、設計通りの光学性能を得るこ
とができないばかりでなく、型材に付着した鉛を取り除
く作業が必要となり、量産化するには不適当であった。
これらの点から、精密プレス成形に用いられる光学ガラ
スは、ガラス成分として酸化鉛を含まず、また可能な限
り低い温度で成形できるものが望まれている。これらの
問題を解決するためとして、上記各公開公報に開示され
ているようなプレス成形用光学ガラスが提案されてい
る。しかし、これらの光学ガラスは、本発明が目的とし
ている光学特性を持っていないばかりか、酸化鉛を含有
しているものも見られる。
In addition, in the optical glass that has been conventionally used,
About 10 to 50% of lead oxide is contained as a glass component. When these optical glasses are used in precision press, lead oxide existing on the glass surface is reduced by the atmosphere because it is usually performed in a reducing atmosphere to prevent the oxidation of the mold material, and it is deposited on the press lens surface and pressed. To evaporate by heating for forming a recess on the surface of the press lens,
The evaporated lead adheres to the surface of the mold material and forms a convex portion, resulting in minute unevenness, and the surface accuracy of the press-molded lens cannot be maintained, so not only the optical performance as designed cannot be obtained. However, it was necessary to remove lead attached to the mold material, which was not suitable for mass production.
From these points, it is desired that the optical glass used for precision press molding does not contain lead oxide as a glass component and can be molded at a temperature as low as possible. In order to solve these problems, press-molding optical glass as disclosed in each of the above publications has been proposed. However, these optical glasses not only do not have the optical characteristics aimed at by the present invention, but also include those containing lead oxide.

【0005】従って本発明の第一の目的は、620℃以
下の低い温度、すなわち屈伏温度(At)より30〜5
0℃高い温度で精密プレスを実施することができる精密
プレス成形用光学ガラスを提供することにある。また本
発明の第二の目的は、第1図に示す点A(1.660,
40.5) 、B(1.660,32.5)、 C(1.5
85,40.5)、D(1.585,39.0)の4点
で囲まれた範囲内の屈折率(nd)及びアッベ数(ν
d)を有する低屈折率高分散の光学ガラスを提供するこ
とにある。
Therefore, the first object of the present invention is to obtain a low temperature of 620 ° C. or lower, that is, a deformation temperature (At) of 30 to 5%.
An object of the present invention is to provide an optical glass for precision press molding that can perform precision press at a temperature as high as 0 ° C. A second object of the present invention is point A (1.660,
40.5), B (1.660, 32.5), C (1.5
85, 40.5), D (1.585, 39.0), and the refractive index (nd) and Abbe number (ν
It is to provide an optical glass having a low refractive index and a high dispersion having d).

【0006】[0006]

【課題を解決するための手段】本発明者等は、以上のよ
うな従来の光学ガラス及びプレス成形用光学ガラスの諸
欠点を鑑みて、種々考察研究した結果、SiO2 、 Ge
2 、TiO2 、Na 2 O、 Li2 Oを必須とするガラ
ス組成の光学ガラスが所定の範囲内において、上記の公
開公報中のプレス成形用光学ガラスにない低屈折率高分
散性の光学特性を備え、さらにプレスレンズ成形時に型
材に対してほとんど影響を及ぼさない充分に低いガラス
軟化温度を持つことを見出し、プレス成形後、研削また
は研磨を必要としない精密プレス用光学ガラスとして最
適であるという結論に達したものである。
The inventors of the present invention have been described above.
Such as conventional optical glass and optical glass for press molding
As a result of various considerations and studies in view of the drawbacks, SiO2, Ge
O2, TiO2, Na 2O, Li2Gala that requires O
Optical glass with a glass composition within the specified range
Low refractive index and high content not found in press-molded optical glass
It has dispersive optical characteristics, and the mold is used for press lens molding.
Low enough glass with little effect on the material
It was found that it has a softening temperature, and after press molding, grinding or
Is the best optical glass for precision presses that does not require polishing.
We have come to the conclusion that it is suitable.

【0007】すなわち、本発明の光学ガラスの組成を重
量%で示すと、SiO2 10.0〜50.0重量%(以
下%で示す)、GeO2 5.0〜52.0%、TiO2
4.0〜25.0%、Nb2 5 0〜25.0%、但
し、SiO2 +GeO2 の合量45.0〜67.0%、
但し、TiO2 +Nb2 5 の合量10.0〜30.0
%、Li2 O1.0〜5.0%、Na2 O5.0〜1
9.0%、K2 O0〜8.0%、Cs2 O0〜20.0
%、但し、Li2 O+Na2 O+K2 O+Cs2 Oの合
量8.0〜32.0%、ZnO0〜10.0%、MgO
0〜8.0%、Al 2 3 0〜6.0、ZrO2 0〜
1.0%、TeO2 0〜3.0%からなる組成を有して
いる。
That is, the composition of the optical glass of the present invention is
In terms of amount%, SiO210.0 to 50.0% by weight (below
(Shown below%), GeO25.0-52.0%, TiO2
4.0-25.0%, Nb2OFive0 to 25.0%, but
And SiO2+ GeO245.0 to 67.0%,
However, TiO2+ Nb2OFiveTotal amount of 10.0-30.0
%, Li2O1.0-5.0%, Na2O5.0-1
9.0%, K2O0-8.0%, Cs2O0-20.0
%, But Li2O + Na2O + K2O + Cs2O's
Amount 8.0 to 32.0%, ZnO 0 to 10.0%, MgO
0-8.0%, Al 2O30-6.0, ZrO20 to
1.0%, TeO2With a composition of 0-3.0%
There is.

【0008】本発明に係る光学ガラスの各成分範囲を上
記のように限定した理由は次のとおりである。SiO2
は、ガラスの網目を構成する主成分であり、ガラスの安
定化、高分散化に有効である。しかし、10.0%より
少ないと、ガラスが不安定になり、50.0%より多く
なると軟化温度の上昇を招き、精密プレスレンズ用のガ
ラスとして適さなくなるばかりでなくガラス中に未溶融
物を生じさせる。GeO2 は、SiO2 と同様ガラスの
網目を構成する成分であると共に、単体でガラスを形成
する成分の中では最も高分散性を示し、さらに通常の同
種の光学ガラスよりも低軟化温度のガラスを提供する上
で必須の成分となっている。しかし、5.0%より少な
いとその効果がなく、52.0%より多くなると化学的
耐久性を悪くし、さらに高屈折率化してしまうのでこの
範囲内とする。またSiO2 、GeO2 の合量が45.
0〜67.0%をこえて増減すると所定の光学恒数が得
られないので所定の範囲内とする。
The reason why each component range of the optical glass according to the present invention is limited as described above is as follows. SiO 2
Is a main component that constitutes the network of glass, and is effective for stabilizing and highly dispersing glass. However, if it is less than 10.0%, the glass becomes unstable, and if it is more than 50.0%, the softening temperature rises, which not only becomes unsuitable as glass for precision press lenses, but also unmelts in the glass. Give rise to. GeO 2 is a component that constitutes a glass network like SiO 2, and has the highest dispersibility among components that form a glass by itself, and is a glass having a lower softening temperature than ordinary optical glass of the same type. Has become an essential ingredient in providing. However, if it is less than 5.0%, the effect is not obtained, and if it is more than 52.0%, the chemical durability is deteriorated and the refractive index is further increased. The total amount of SiO 2 and GeO 2 is 45.
If it increases or decreases beyond 0 to 67.0%, a predetermined optical constant cannot be obtained, so it is set within a predetermined range.

【0009】TiO2 は、本発明において最も重要な必
須成分である。通常低屈折率高分散性の光学ガラスは、
その低屈折率高分散の性質をガラスに持たせるためにP
bO成分を必須としている。しかしながら本発明におけ
る光学ガラスは、精密プレスレンズ用のガラスであるた
めに、プレス用型材に悪影響を及ぼす成分であるPbO
は使用することができない。そこでPbOと同様の光学
的性質をガラスに持たせ、かつプレス用型材に悪影響を
及ぼすことがない最も有効な成分として、本発明におい
てはTiO2 を必須としている。しかし、4.0%より
少ないと上記効果が得られず、25.0%より多くなる
とガラスが不安定となるので所定の範囲内とする。Nb
2 5 は、TiO2 と同様PbO成分の代わりに低屈折
率高分散性をガラスに与えるための成分である。しか
し、TiO2 程の効果はなく、高分散性よりも高屈折率
化への影響の方が大きいため、TiO2 と併用すること
によって、光学恒数の調整を行う成分としている。しか
し、25.0%より多くなると所定の光学恒数よりも高
屈折率となり、さらに失透傾向を増大する。またTiO
2 、Nb2 5 は、その合量が10.0〜30.0%を
超えて増減すると所定の光学恒数が得られないのでこの
範囲内とする。
TiO 2 is the most important essential component in the present invention. Optical glasses with low refractive index and high dispersion are usually
To give the glass the property of low refractive index and high dispersion, P
The bO component is essential. However, since the optical glass in the present invention is a glass for precision press lenses, it is a component that adversely affects the press mold material, that is, PbO.
Can not be used. Therefore, TiO 2 is indispensable in the present invention as the most effective component that gives glass the same optical properties as PbO and does not adversely affect the pressing mold material. However, if it is less than 4.0%, the above effect cannot be obtained, and if it exceeds 25.0%, the glass becomes unstable, so the content is made within the predetermined range. Nb
2 O 5 is a component for giving glass a low refractive index and high dispersibility, instead of the PbO component, like TiO 2 . However, no effect of TiO 2 degree, since than highly disperse better effects on the high refractive index larger, in conjunction with TiO 2, and a component for adjusting the optical constants. However, if it exceeds 25.0%, the refractive index becomes higher than the predetermined optical constant, and the devitrification tendency further increases. Also TiO
2 and Nb 2 O 5 are within this range because a predetermined optical constant cannot be obtained if the total amount of Nb 2 O 5 increases or decreases beyond 10.0 to 30.0%.

【0010】Li2 Oは、アルカリ成分中では最もガラ
スの軟化温度を下げる効果を持ち、かつ最もガラスの化
学的耐久性を悪くしない成分である。しかし、その使用
割合が多くなるとガラスを非常に不安定化し、結晶化傾
向を増大させてしまうので、本発明においては、少量の
必須成分として1.0〜5.0%以内にその使用量を限
定している。Na2 Oは、アルカリ成分の中では、Li
2 Oについでガラスの軟化温度を下げる効果を持つ成分
である。しかし、Li2 Oと異なりその使用量を増して
もガラスの安定性を損なうことがないので、本発明にお
いて最も使用量の多いアルカリ必須成分である。しか
し、5.0%より少ないとその効果は少なく、19.0
%より多くなるとガラスの化学的耐久性を悪くするので
所定の範囲内とする。K2 Oは、Li2 O、Na2 Oに
比較するとガラスの軟化温度の低温度化には効果がな
く、その使用量を多くするとガラスの化学的耐久性を非
常に悪くしてしまう。しかし、低屈折率高分散性をガラ
スに持たせる性質があるため、8.0%以下で使用して
いる。Cs2 Oは、アルカリ成分中で最も低屈折率高分
散化に有効な成分であり、多く使用してもガラスの安定
性を損なうことがない。しかし、軟化温度の低温度化に
はほとんど効果がなく、20.0%より多くなると化学
的耐久性を悪くするので所定の範囲内とする。Li2
、Na2 O 、K2 O 、Cs2 Oは、他の成分よりも軟化
温度の低下に有効な成分であり、また低屈折率高分散化
にも有効である。しかし、その合量が8.0%より少な
いとその効果は少なく、32.0%より多くなるとガラ
スの化学的耐久性を悪くするので、所定の範囲内とす
る。
Li 2 O is a component which has the effect of lowering the softening temperature of glass most among the alkaline components and which does not deteriorate the chemical durability of glass most. However, if the use ratio increases, the glass becomes very unstable and the crystallization tendency increases, so in the present invention, the use amount is within 1.0 to 5.0% as a small amount of an essential component. Limited. Na 2 O is Li in the alkaline component.
It is a component that has the effect of lowering the softening temperature of glass following 2 O. However, unlike Li 2 O, the stability of the glass is not impaired even if the amount used is increased, so it is the most essential alkaline component used in the present invention. However, if it is less than 5.0%, the effect is small, and it is 19.0.
%, The chemical durability of the glass deteriorates, so the content is set within the prescribed range. Compared to Li 2 O and Na 2 O, K 2 O is not effective in lowering the softening temperature of glass, and if the amount of K 2 O used is large, the chemical durability of glass is extremely deteriorated. However, since the glass has a property of having a low refractive index and high dispersibility, it is used at 8.0% or less. Cs 2 O is the most effective component in the alkali component for achieving a low refractive index and high dispersion, and does not impair the stability of the glass even if it is used in a large amount. However, it has almost no effect on lowering the softening temperature, and if it exceeds 20.0%, the chemical durability is deteriorated, so the content is set within the predetermined range. Li 2 O
, Na 2 O, K 2 O, and Cs 2 O are more effective than other components in lowering the softening temperature, and are also effective in lowering the refractive index and increasing the dispersion. However, if the total content is less than 8.0%, the effect is small, and if it exceeds 32.0%, the chemical durability of the glass is deteriorated, so the content is set within the predetermined range.

【0011】ZnOは、軟化温度の低下に有効であるが
10.0%より多くなると高屈折率化してしまうので所
定の範囲内とする。MgOは、低屈折率化に有効な成分
であるが、8.0%より多くなると失透傾向を増してし
まう。Al2 3 は、ガラスの化学的耐久性を非常に良
くする成分であるが、6.0%より多くなると軟化温度
を上昇させてしまう。ZrO2 は、Al2 3 と同様化
学的耐久性を向上させるが、1.0%より多くなると軟
化温度を上昇させるとともに、失透傾向を増してしま
う。TeO2 は、高屈折率高分散に有効な成分である。
このため、3.0%以下と少量加えることにより光学恒
数の調整を行わせている。
ZnO is effective in lowering the softening temperature, but if it exceeds 10.0%, the refractive index becomes high, so it is within the predetermined range. MgO is an effective component for lowering the refractive index, but if it exceeds 8.0%, the devitrification tendency increases. Al 2 O 3 is a component that greatly improves the chemical durability of glass, but if it exceeds 6.0%, the softening temperature rises. ZrO 2 improves the chemical durability like Al 2 O 3 , but if it exceeds 1.0%, it raises the softening temperature and the devitrification tendency increases. TeO 2 is a component effective for high refractive index and high dispersion.
Therefore, the optical constant is adjusted by adding a small amount of 3.0% or less.

【0012】本発明の光学ガラスには、上記成分の他
に、光学性能の調整、溶融性の改善、ガラス化範囲の拡
大及び軟化温度の低温度化等のために、本発明の目的か
らはずれない限り、Ca 、Sr 、Ba 、Ga 、In 、Y
、La 、Ta 、Gd 、Ybなどの金属酸化物、ハロゲン
化物を含有させることができる。
In addition to the above components, the optical glass of the present invention deviates from the object of the present invention in order to adjust the optical performance, improve the melting property, expand the vitrification range and lower the softening temperature. Unless otherwise specified, Ca, Sr, Ba, Ga, In, Y
, La 2, Ta 3, Gd 2, Yb and other metal oxides and halides may be contained.

【0013】本発明の光学ガラスは、各成分の原料とし
て各々相当する酸化物、水酸化物、炭酸塩、硝酸塩、ハ
ロゲン化物等を使用し、ガラス化した後に目的とするガ
ラス組成の割合となるように秤量し、充分混合してガラ
ス調合原料として、白金製坩堝に投入し、電気炉で、1
000℃〜1400℃で溶融し、白金製撹拌棒にて撹拌
して、清澄、均質化してから適当な温度に予熱した金型
内に鋳込んだ後、徐冷して製造することができる。
The optical glass of the present invention uses the corresponding oxides, hydroxides, carbonates, nitrates, halides, etc. as raw materials for the respective components, and after vitrification, the ratio of the desired glass composition is obtained. As weighed, mixed well and put into a platinum crucible as a glass compounding raw material, and put it in an electric furnace for 1
It can be produced by melting at 000 ° C to 1400 ° C, stirring with a stirring rod made of platinum, refining and homogenizing, casting in a mold preheated to an appropriate temperature, and then gradually cooling.

【0014】[0014]

【実施例】以下実施例を挙げて本発明の光学ガラスを具
体的に説明するが、本発明はこれらに限定されるもので
はない。 実施例1〜24 本発明に係る実施例の組成(数値は重量%)、及びその特
性値としての屈折率(nd)、アッベ数( νd)、屈伏
温度(At)を表−1に示す。 本発明の光学ガラス
は、各成分の原料として各々相当する酸化物、水酸化
物、炭酸塩、硝酸塩、ハロゲン化物等を使用し、ガラス
化した後に表−1の各実施例組成の割合となるように秤
量し、充分混合してガラス調合原料として、白金製坩堝
に投入して電気炉で、1000℃〜1400℃で溶融
し、白金製撹拌棒にて撹拌して、清澄、均質化してから
適当な温度に予熱した金型内に鋳込んだ後、徐冷して作
る。なおガラスの着色を防ぎ、脱泡のため少量のAs2
3 を加えること、または工業上良く知られている脱泡
成分の少量添加は、本発明の効果に影響を与えない。
EXAMPLES The optical glass of the present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Examples 1 to 24 Table 1 shows compositions (numerical values are% by weight), refractive index (nd), Abbe number (νd), and deformation temperature (At) as characteristic values of Examples according to the present invention. The optical glass of the present invention uses corresponding oxides, hydroxides, carbonates, nitrates, halides, etc. as raw materials for the respective components, and after vitrification, the composition ratios of the respective examples in Table 1 are obtained. As weighed and thoroughly mixed as a glass compounding raw material into a platinum crucible and melted in an electric furnace at 1000 ° C. to 1400 ° C., stirred with a platinum stirring rod, clarified and homogenized, It is made by casting in a mold preheated to an appropriate temperature and then slowly cooling. In addition, a small amount of As 2 is used to prevent the glass from coloring and to remove bubbles.
Addition of O 3 or addition of a small amount of defoaming component well known in the industry does not affect the effect of the present invention.

【0015】次に得られたガラスから、所定重量のガラ
ス塊を切り出し、従来の研磨法により球状に研磨し、こ
れをプリフォームとして500〜610℃で精密プレス
を行うことにより24種類の製品を得た。これらのプレ
スレンズの形状を測定した結果、いずれも1.0μm以
下の形状誤差を示し、良好な転写性を示すと共に、型材
へのガラス付着、揮発物の付着などは認められなかっ
た。
Next, from the obtained glass, a glass lump of a predetermined weight is cut out, ground into a spherical shape by a conventional polishing method, and this is used as a preform for precision press at 500 to 610 ° C. to obtain 24 kinds of products. Obtained. As a result of measuring the shape of these press lenses, all showed a shape error of 1.0 μm or less, and showed good transferability, and neither glass adhesion nor volatile matter adhesion to the mold material was observed.

【0016】比較例1〜2 従来公知の光学ガラスで通常F2、BaSF4と呼ばれ
るガラスの組成を表−2に示し比較例として作製した。
この組成を用いて実施例1〜24と同様にガラスを製造
し、プリフォームを作成し、加熱された還元性雰囲気の
中にプリフォームを置いてその表面状態を観察した。そ
の結果、精密プレス成形を行うまでもなく、鏡面状態で
あったプリフォームの表面が還元され、鉛の析出が認め
られ曇った状態に変化した。
Comparative Examples 1 and 2 Conventionally known optical glasses, which are usually called F2 and BaSF4, are shown in Table 2 as a comparative example.
Using this composition, glass was manufactured in the same manner as in Examples 1 to 24 to prepare a preform, and the preform was placed in a heated reducing atmosphere and the surface condition was observed. As a result, the surface of the preform, which was in a mirror-like state, was reduced without lead to precision press-molding, and lead deposition was observed and changed to a cloudy state.

【0017】[0017]

【表1】 [Table 1]

【0018】[0018]

【表2】 [Table 2]

【0019】[0019]

【表3】 [Table 3]

【0020】[0020]

【表4】 [Table 4]

【0021】[0021]

【表5】 [Table 5]

【0022】[0022]

【発明の効果】本発明によれば、屈伏温度(At)が5
70℃以下で、かつ図1に示す点A(1.660,4
0.5) 、B(1.660,32.5)、 C(1.58
5,40.5)、D(1.585,39.0)の4点で
囲まれた範囲内の屈折率(nd)及びアッベ数(νd)
を有し、失透に対して安定であり、極めて低い温度でプ
レス成形が可能なため、プレス成形後、研削または研磨
を必要としない精密プレス用光学ガラスとして有用であ
る。
According to the present invention, the yield temperature (At) is 5
Point A (1.660,4
0.5), B (1.660, 32.5), C (1.58)
5, 40.5), D (1.585, 39.0), and the refractive index (nd) and Abbe number (νd) within a range surrounded by four points.
It is stable against devitrification and can be press-molded at an extremely low temperature. Therefore, it is useful as an optical glass for precision press that does not require grinding or polishing after press-molding.

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

【図1】 本発明のガラスの光学恒数領域を示す光学恒
数図(nd−νd 図) である。
FIG. 1 is an optical constant diagram (nd-νd diagram) showing an optical constant region of glass of the present invention.

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】SiO2 10.0〜50.0重量%(以下
%で示す)、GeO 2 5.0〜52.0%、TiO
2 4.0〜25.0%、Nb2 5 0〜25.0%、但
し、SiO2 +GeO2 の合量45.0〜67.0%、
但し、TiO2 +Nb2 5 の合量10.0〜30.0
%、Li2 O1.0〜5.0%、Na2 O5.0〜1
9.0%、K2 O0〜8.0%、Cs2 O0〜20.0
%、但し、Li2 O+Na2 O+K2 O+Cs2 Oの合
量8.0〜32.0%、ZnO0〜10.0%、MgO
0〜8.0%、Al2 3 0〜6.0%、ZrO2 0〜
1.0%、TeO2 0〜3.0%の組成からなる、屈伏
温度(At)が570℃以下で、かつ第1図に示す点、
A(1.660,40.5) 、B(1.660,32.
5) 、C(1.585,40.5)、D(1.585,
39.0)の4点で囲まれた範囲内の屈折率(nd)及
びアッベ数(νd)を有する低屈折率高分散の精密プレ
ス用光学ガラス。
1. SiO210.0 to 50.0% by weight (hereinafter
%), GeO 25.0-52.0%, TiO
24.0-25.0%, Nb2OFive0 to 25.0%, but
And SiO2+ GeO245.0 to 67.0%,
However, TiO2+ Nb2OFiveTotal amount of 10.0-30.0
%, Li2O1.0-5.0%, Na2O5.0-1
9.0%, K2O0-8.0%, Cs2O0-20.0
%, But Li2O + Na2O + K2O + Cs2O's
Amount 8.0 to 32.0%, ZnO 0 to 10.0%, MgO
0-8.0%, Al2O30-6.0%, ZrO20 to
1.0%, TeO2Sagging consisting of 0-3.0% composition
The temperature (At) is 570 ° C. or lower and the point shown in FIG.
A (1.660, 40.5), B (1.660, 32.
5), C (1.585, 40.5), D (1.585,
39.0) and the refractive index (nd) within the range surrounded by four points
And high Abbe number (νd), low refractive index and high dispersion precision pre
Optical glass for mobile phones.
JP04190763A 1992-07-17 1992-07-17 Optical glass for precision press Expired - Lifetime JP3122236B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP04190763A JP3122236B2 (en) 1992-07-17 1992-07-17 Optical glass for precision press

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP04190763A JP3122236B2 (en) 1992-07-17 1992-07-17 Optical glass for precision press

Publications (2)

Publication Number Publication Date
JPH0632631A true JPH0632631A (en) 1994-02-08
JP3122236B2 JP3122236B2 (en) 2001-01-09

Family

ID=16263323

Family Applications (1)

Application Number Title Priority Date Filing Date
JP04190763A Expired - Lifetime JP3122236B2 (en) 1992-07-17 1992-07-17 Optical glass for precision press

Country Status (1)

Country Link
JP (1) JP3122236B2 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002087841A (en) * 2000-07-14 2002-03-27 Hoya Corp Optical glass, precision press molding stock and optical part
US6759471B1 (en) 1999-07-01 2004-07-06 Canon Kabushiki Kaisha Optical material and optical system using it
US6917475B2 (en) 2002-06-17 2005-07-12 Olympus Corporation Optical element
JP2008110917A (en) * 2001-10-15 2008-05-15 Hoya Corp Glass material for press molding and method for producing same, method for producing glass press molded article and method for producing optical element
US8120851B2 (en) 2007-01-11 2012-02-21 Canon Kabushiki Kaisha Optical material and optical element, diffraction optical element, and stacked type diffraction optical element molded thereof
US8479539B2 (en) 2001-10-15 2013-07-09 Hoya Corporation Optical glass, glass material for press molding, optical element, and method of manufacturing same

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6759471B1 (en) 1999-07-01 2004-07-06 Canon Kabushiki Kaisha Optical material and optical system using it
US7196132B2 (en) 1999-07-01 2007-03-27 Canon Kabushiki Kaisha Optical material and optical system using it
JP2002087841A (en) * 2000-07-14 2002-03-27 Hoya Corp Optical glass, precision press molding stock and optical part
JP2008110917A (en) * 2001-10-15 2008-05-15 Hoya Corp Glass material for press molding and method for producing same, method for producing glass press molded article and method for producing optical element
US8479539B2 (en) 2001-10-15 2013-07-09 Hoya Corporation Optical glass, glass material for press molding, optical element, and method of manufacturing same
US6917475B2 (en) 2002-06-17 2005-07-12 Olympus Corporation Optical element
US8120851B2 (en) 2007-01-11 2012-02-21 Canon Kabushiki Kaisha Optical material and optical element, diffraction optical element, and stacked type diffraction optical element molded thereof

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