JP3168221B2 - Infrared optical device - Google Patents
Infrared optical deviceInfo
- Publication number
- JP3168221B2 JP3168221B2 JP04690092A JP4690092A JP3168221B2 JP 3168221 B2 JP3168221 B2 JP 3168221B2 JP 04690092 A JP04690092 A JP 04690092A JP 4690092 A JP4690092 A JP 4690092A JP 3168221 B2 JP3168221 B2 JP 3168221B2
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- Japan
- Prior art keywords
- lens
- optical system
- optical device
- infrared
- thermal
- Prior art date
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- Expired - Lifetime
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- Transforming Light Signals Into Electric Signals (AREA)
Description
【０００１】[0001]
【産業上の利用分野】この発明は赤外線カメラに用いる
赤外線光学装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared optical device used for an infrared camera.
【０００２】[0002]
【従来の技術】一般に、温度が変化すると、レンズの屈
折率変化、熱伸縮によるレンズの形状変化、レンズ間隔
変化等により、赤外線光学装置の結像位置が移動して、
解像度が劣化する（以下、この現象を熱収差と呼ぶ）。
この熱収差を抑制するためには、結像位置の移動を何等
かの方法で補正をする必要がある。2. Description of the Related Art In general, when the temperature changes, the imaging position of the infrared optical device moves due to a change in the refractive index of the lens, a change in the shape of the lens due to thermal expansion and contraction, and a change in the distance between the lenses.
The resolution is degraded (hereinafter, this phenomenon is called thermal aberration).
In order to suppress this thermal aberration, it is necessary to correct the movement of the imaging position by some method.
【０００３】従来のこの種の赤外線光学装置として、例
えばＵ．Ｓ．Ｐａｔ．Ｎｏ．４，４３１，９１７に示さ
れたものがあり、図４は上記文献に示された赤外線光学
装置の構成断面図である。図４において、１はドーム、
２は第１の反射鏡、３は第１の反射鏡２と同軸の第２の
反射鏡、４は上記の反射鏡２，３を備えた反射光学系、
５〜７は第１〜第３のレンズ、１０は第１〜第３のレン
ズ５〜７からなる屈折光学系、１１は屈折光学系１０よ
り後側に配置された絞り、１２は検出器、２０は入射赤
外線である。As a conventional infrared optical device of this type, for example, U.S. Pat. S. Pat. No. 4,431,917, and FIG. 4 is a sectional view showing the configuration of an infrared optical device disclosed in the above-mentioned document. In FIG. 4, 1 is a dome,
2 is a first reflecting mirror, 3 is a second reflecting mirror coaxial with the first reflecting mirror 2, 4 is a reflecting optical system having the above-mentioned reflecting mirrors 2 and 3,
5 to 7 are first to third lenses, 10 is a refractive optical system including the first to third lenses 5 to 7, 11 is a stop disposed behind the refractive optical system 10, 12 is a detector, 20 is an incident infrared ray.
【０００４】上記のように構成された装置において、撮
像対象物からの波長８〜１２μｍ近辺の入射赤外線２０
は、ドーム１を通り、反射光学系４で集光された後、屈
折光学系１０で再集光されて、この赤外線光学装置の結
像位置に置かれた検出器１２により電気信号に変換され
る。以後については、図４には図示していないが、上記
検出器１２の出力信号は信号処理回路を介して表示装置
に出力される。屈折光学系１０は２種類の材料から成っ
ており、色収差と熱収差を低減するように構成されてい
る。In the apparatus configured as described above, an incident infrared ray 20 having a wavelength of about 8 to 12 μm from an object to be imaged is used.
Passes through the dome 1 and is condensed by the reflection optical system 4, then re-condensed by the refraction optical system 10, and converted into an electric signal by the detector 12 located at the image forming position of the infrared optical device. You. Thereafter, although not shown in FIG. 4, the output signal of the detector 12 is output to the display device via the signal processing circuit. The refractive optical system 10 is made of two types of materials, and is configured to reduce chromatic aberration and thermal aberration.
【０００５】次に、レンズＡ，Ｂから成る２枚組の薄肉
近接光学系を例にとって色収差及び熱収差の補正につい
て説明する。Next, correction of chromatic aberration and thermal aberration will be described with reference to a pair of thin-walled close proximity optical systems composed of lenses A and B as an example.
【０００６】先ず、色収差について説明する。よく知ら
れているように薄肉近接光学系の軸上色収差Δｆは次式
で与えられる。 Δｆ＝ｆ2 ｛１／（ｆA ＶA ）＋１／（ｆB ＶB ）｝ （１） 但し、ｆA ： レンズＡの焦点距離 ｆB ： レンズＢの焦点距離 ｆ ： レンズＡとレンズＢの合成焦点距離 ＶA ： レンズＡの材料のアッベ数 ＶB ： レンズＢの材料のアッベ数First, the chromatic aberration will be described. As is well known, the axial chromatic aberration Δf of the thin proximity optical system is given by the following equation. Δf = f 2 {1 / ( f A V A) + 1 / (f B V B)} (1) where, f A: focal length of the lens A f B: the focal length f of the lens B: Lens A lens B V A : Abbe number of material of lens A V B : Abbe number of material of lens B
【０００７】次に、熱収差について説明する。合成焦点
距離ｆは、次式で与えられる。 １／ｆ＝１／ｆA ＋１／ｆB （２） ＝（ｎA −１）（１／ＲA1−１／ＲA2） ＋（ｎB −１）（１／ＲB1−１／ＲB2） （３） 但し、ｎA ： レンズＡの材料の屈折率 ｎB ： レンズＢの材料の屈折率 ＲA1： レンズＡの第１面の曲率半径 ＲA2： レンズＡの第２面の曲率半径 ＲB1： レンズＢの第１面の曲率半径 ＲB2： レンズＢの第２面の曲率半径Next, the thermal aberration will be described. The composite focal length f is given by the following equation. 1 / f = 1 / f A + 1 / f B (2) = (n A -1) (1 / R A1 -1 / R A2) + (n B -1) (1 / R B1 -1 / R B2 (3) where n A : refractive index of the material of the lens A n B : refractive index of the material of the lens B RA 1 : radius of curvature of the first surface of the lens A RA A2 : radius of curvature of the second surface of the lens A R B1 : radius of curvature of the first surface of lens B R B2 : radius of curvature of the second surface of lens B
【０００８】熱収差は、上記の合成焦点距離ｆを温度Ｔ
で微分して、式４で表せる。[0008] The thermal aberration is calculated by changing the above-mentioned combined focal length f to
And can be expressed by Equation 4.
【０００９】[0009]
【数１】 (Equation 1)
【００１０】ここで、色収差におけるアッベ数と同様
に、熱アッベ数を式５のように定義すると、色収差を表
す式１に類似した熱収差を表す式６を得る。Here, if the thermal Abbe number is defined as in equation 5 similarly to the Abbe number in chromatic aberration, equation 6 representing thermal aberration similar to equation 1 representing chromatic aberration is obtained.
【００１１】[0011]
【数２】 (Equation 2)
【００１２】以上より、色収差と熱収差を同時に補正す
る条件を、式１、式２、式６より求めると次式のように
なる。 ＶA ／ＶTA＝ＶB ／ＶTB （７）From the above, when the conditions for simultaneously correcting the chromatic aberration and the thermal aberration are obtained from Expressions 1, 2, and 6, the following expression is obtained. V A / V TA = V B / V TB (7)
【００１３】図５は、両収差を同時に補正する条件を満
足する材料の組み合わせを説明する図である。横軸がア
ッベ数、縦軸が熱アッベ数であり、両収差を同時に補正
する条件を満足する材料は、図５に示す原点を通る直線
上にある材料の組み合わせのものである。図６は、８〜
１２μｍ近辺の波長における代表的な赤外線透過材料の
アッベ数と熱アッベ数を示す図である。従来の赤外線光
学装置では、屈折光学系の２種類の材料の組み合わせ
を、アッベ数と熱アッベ数の比が比較的近い硫化亜鉛
（ＺｎＳ）とＴＩ１１７３（商品名、テキサス・インス
トルメンツ社製）としている。図４の正レンズである第
１のレンズ５及び第３のレンズ７の材料は硫化亜鉛、負
レンズである第２のレンズ６の材料はＴＩ１１７３であ
る。従来装置では、この屈折光学系４により、撮像対象
物から放射された波長の異なる入射赤外線２０がほぼ同
じ位置に結像するので色収差が小さく、温度変化による
上記結像位置の移動が小さいので熱収差も小さく抑えら
れている。FIG. 5 is a diagram for explaining a combination of materials that satisfies the condition for simultaneously correcting both aberrations. A material that satisfies the condition for simultaneously correcting both aberrations, where the horizontal axis is the Abbe number and the vertical axis is the thermal Abbe number, is a combination of materials on a straight line passing through the origin shown in FIG. FIG.
It is a figure which shows Abbe number and thermal Abbe number of a typical infrared transmission material in the wavelength around 12 micrometers. In a conventional infrared optical device, a combination of two kinds of materials of a refractive optical system is zinc sulfide (ZnS) and TI1173 (trade name, manufactured by Texas Instruments) whose Abbe number and thermal Abbe number ratio are relatively close. I have. The material of the first lens 5 and the third lens 7 as the positive lens in FIG. 4 is zinc sulfide, and the material of the second lens 6 as the negative lens is TI1173. In the conventional apparatus, the refracting optical system 4 forms incident infrared rays 20 having different wavelengths emitted from the object to be imaged at almost the same position, so that the chromatic aberration is small. Aberration is also kept small.
【００１４】[0014]
【発明が解決しようとする課題】従来の赤外線光学装置
は以上のように構成されていて、図６に示すようにアッ
ベ数と熱アッベ数の比が等しい２種類の材料の組み合わ
せは存在しないので、式７の条件を満足せず、色収差と
熱収差をさらに小さく抑えることができないという課題
があった。この発明は上記のような課題を解決するため
になされたもので、色収差と熱収差を従来の赤外線光学
装置に比べ小さくして色収差と熱収差による解像度の劣
化を抑えた赤外線光学装置を得ることを目的とする。The conventional infrared optical device is constructed as described above, and as shown in FIG. 6, there is no combination of two kinds of materials having the same ratio between the Abbe number and the thermal Abbe number. Therefore, there is a problem that the condition of Expression 7 is not satisfied, and the chromatic aberration and the thermal aberration cannot be further reduced. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an infrared optical device in which chromatic aberration and thermal aberration are reduced as compared with a conventional infrared optical device, and deterioration of resolution due to chromatic aberration and thermal aberration is suppressed. With the goal.
【００１５】[0015]
【課題を解決するための手段】上記の目的を達成するた
めに、この発明に係わる赤外線光学装置は、撮像対象物
からの入射赤外線を集光する反射光学系と、屈折光学系
と、検出器とで構成する光学装置において、入射赤外線
を上記検出器へ入射させる屈折光学系として、ｉを１な
いしｎまでの任意の番号として、ｆをレンズの焦点距
離、Ｖをレンズ材料のアッベ数、Ｖ T をレンズ材料の熱
アッベ数、Ｔを温度とするとき、 を概略、同時に満足するゲルマニウムを含む合計３種類
以上の材料を用いるようにしたものである。In order to achieve the above object, an infrared optical device according to the present invention comprises a reflecting optical system for collecting incident infrared light from an object to be imaged, a refractive optical system, and a detector. In the optical device configured by the above, i is one as a refractive optical system for making incident infrared light incident on the detector.
F is the focal length of the lens as an arbitrary number up to the chair n
Away, the Abbe number of the V lens material, the heat of the V T lens material
When Abbe number and T are temperature, In general, three or more kinds of materials containing germanium satisfying at the same time are used .
【００１６】[0016]
【作用】上記のように構成された赤外線光学装置では、
屈折光学系を少なくとも３種類の材料から構成すること
により、上記光学系の色収差と熱収差とを同時に補正す
る条件を満足し、波長の異なる入射赤外線をほぼ同じ位
置に結像し、温度が変化しても上記結像位置がほとんど
移動しないようにすることができる。In the infrared optical device configured as described above,
By forming the refractive optical system from at least three kinds of materials, the condition for simultaneously correcting the chromatic aberration and the thermal aberration of the optical system is satisfied, the incident infrared rays having different wavelengths are imaged at almost the same position, and the temperature changes. Even if it does, the imaging position can hardly move.
【００１７】[0017]
実施例１．図１はこの発明の実施例１を示す赤外線光学
装置の構成断面図である。図において、１〜４、１１〜
１２、２０は従来装置と同一のものであり、５〜９は第
１〜第５のレンズ、１０は第１〜第５のレンズ５〜９か
ら成る屈折光学系であり、３種類の材料から成ってい
る。Embodiment 1 FIG. FIG. 1 is a sectional view showing the configuration of an infrared optical device according to Embodiment 1 of the present invention. In the figure, 1-4, 11-
Numerals 12 and 20 are the same as those of the conventional apparatus, 5 to 9 are first to fifth lenses, and 10 is a refractive optical system including first to fifth lenses 5 to 9; Made up of
【００１８】上記のように構成された装置において、従
来装置の場合と同様に、入射赤外線２０はドーム１を通
り、反射光学系４で一度結像された後、屈折光学系１０
で再結像されて、この赤外線光学装置の結像位置の置か
れた検出器１２で電気信号に変換される。In the apparatus configured as described above, similarly to the conventional apparatus, the incident infrared ray 20 passes through the dome 1 and is once imaged by the reflection optical system 4 and then formed by the refraction optical system 10.
The image is re-formed and converted into an electric signal by the detector 12 located at the image forming position of the infrared optical device.
【００１９】ここで、それぞれ材料の異なるｎ枚組のレ
ンズ厚と間隔を無視した薄肉近接光学系（ｎ：正の整
数）を例にとって、色収差及び熱収差の補正条件を説明
する。焦点距離の合成式、色収差の補正式、熱収差の補
正式をそれぞれ以下に示す。Here, correction conditions for chromatic aberration and thermal aberration will be described by taking an example of a thin proximity optical system (n: a positive integer) ignoring lens thicknesses and intervals of n sets of different materials. The focal length synthesis formula, chromatic aberration correction formula, and thermal aberration correction formula are shown below.
【００２０】[0020]
【数３】 (Equation 3)
【００２１】これらの式を満足する場合、色収差と熱収
差が同時に補正される。２種類の材料から成る２枚組光
学系の場合、上記の式８，式９，式１０を満足する解を
求めると、上記の式７となり、材料が限定され、かつ、
それぞれのレンズの焦点距離比が一意的に決まる。しか
し、図６に示したように式７を満足する材料の組み合わ
せはない。When these expressions are satisfied, chromatic aberration and thermal aberration are corrected simultaneously. In the case of a two-unit optical system composed of two types of materials, when a solution that satisfies Equations 8, 9, and 10 is obtained, Equation 7 is obtained, and the material is limited.
The focal length ratio of each lens is uniquely determined. However, there is no material combination that satisfies Equation 7 as shown in FIG.
【００２２】ところが、３種類の材料から成る３枚組光
学系にすると、自由度が増し、３元１次方程式となり、
材料の特性によらず、一意的に決まる各レンズの焦点距
離比により、上記３式を満足する解が存在する。したが
って、少なくとも３種類の材料を用いれば、色収差と熱
収差を同時に補正することができる。However, if a three-element optical system made of three types of materials is used, the degree of freedom is increased and a three-dimensional linear equation is obtained.
There is a solution that satisfies the above three equations depending on the focal length ratio of each lens that is uniquely determined regardless of the characteristics of the material. Therefore, if at least three types of materials are used, chromatic aberration and thermal aberration can be corrected simultaneously.
【００２３】４枚組光学系以上では、さらに自由度が増
し、上記３式を満足する各レンズの焦点距離比の組み合
わせは無数に存在する。以上、簡単のためレンズ厚及び
間隔を無視して説明したが実際の光学系ではそれら両者
を考慮しなければならない。しかし、概ね以上の説明に
従う。また、反射鏡の形状変化やレンズ保持具の伸縮を
も考慮する必要のある場合には、式１０を満足するよう
上記形状変化及び伸縮と熱収差とが相殺するようにすれ
ばよい。With a four-element optical system or more, the degree of freedom is further increased, and there are countless combinations of the focal length ratios of the lenses that satisfy the above three equations. As described above, for simplicity, the description has been made while ignoring the lens thickness and the interval, but in an actual optical system, both of them must be considered. However, the above description is generally followed. When it is necessary to consider the shape change of the reflecting mirror and the expansion and contraction of the lens holder, the shape change and the expansion and contraction and the thermal aberration may be canceled so as to satisfy Expression 10.
【００２４】この発明の実施例１を示す赤外線光学装置
の屈折光学系１０は、３種類の材料（ゲルマニウム、セ
レン化亜鉛、硫化亜鉛）で構成したものであるが、材料
による色収差と熱収差以外のレンズ形状による収差を低
減するために、セレン化亜鉛の材料のレンズを３枚に分
割し、５枚組光学系としている。屈折光学系１０の各レ
ンズの材料及びパワー配分は、それぞれ以下の通りであ
る。第１のレンズ５はゲルマニウムから成り負のパワ
ー、第２のレンズ６、第３のレンズ７、及び第５のレン
ズ９はセレン化亜鉛から成り正のパワー、第４のレンズ
８は硫化亜鉛から成り負のパワーである。なお、第１の
反射鏡２、第２の反射鏡３、及び保持部の材料はアルミ
ニウムとしている。各材料の各波長光に対する屈折率、
アッべ数、屈折率の温度変化、線膨脹率、熱アッベ数は
表１の通りである。The refractive optical system 10 of the infrared optical device according to the first embodiment of the present invention is made of three kinds of materials (germanium, zinc selenide, zinc sulfide). In order to reduce aberrations due to the lens shape, a lens made of zinc selenide is divided into three lenses to form a five-element optical system. Materials and power distribution of each lens of the refractive optical system 10 are as follows. The first lens 5 is made of germanium and has a negative power, the second lens 6, the third lens 7 and the fifth lens 9 are made of zinc selenide and has a positive power, and the fourth lens 8 is made of zinc sulfide. Negative power. The material of the first reflecting mirror 2, the second reflecting mirror 3, and the holding portion is aluminum. Refractive index for each wavelength light of each material,
Table 1 shows the Abbe number, the temperature change of the refractive index, the linear expansion coefficient, and the thermal Abbe number.
【００２５】[0025]
【表１】 [Table 1]
【００２６】図１に示したこの発明の赤外線光学装置
は、焦点距離を１００ｍｍ、Ｆ値を２．５、画角を全角
２°としたものであり、その変調伝達関数（以下、ＭＴ
Ｆと呼ぶ）を図２（ａ）に、温度変化に対する結像位置
の移動量を図２（ｂ）に、それぞれ示す。ＭＴＦはほぼ
回折限界であり、諸収差が補正されている。また、温度
変化に対する結像位置の移動が極めて小さく、温度によ
るＭＴＦの劣化がほとんどない。The infrared optical device of the present invention shown in FIG. 1 has a focal length of 100 mm, an F-number of 2.5 and an angle of view of 2 °, and its modulation transfer function (hereinafter MT).
F) is shown in FIG. 2A, and the amount of movement of the imaging position with respect to the temperature change is shown in FIG. 2B. MTF is almost diffraction-limited, and various aberrations are corrected. Further, the movement of the imaging position with respect to the temperature change is extremely small, and the MTF hardly deteriorates due to the temperature.
【００２７】以上のように、この赤外線光学装置は、撮
像対象物から放射された波長の異なる入射赤外線２０が
ほぼ同じ結像位置に結像するので色収差による劣化が抑
えられており、温度が変化しても上記結像位置がほとん
ど移動せず温度変化による解像度の劣化が抑えられてい
る。As described above, in this infrared optical device, the incident infrared rays 20 having different wavelengths emitted from the object to be imaged are imaged at almost the same image forming position, so that deterioration due to chromatic aberration is suppressed, and the temperature changes. Even if the image formation position hardly moves, the deterioration of the resolution due to the temperature change is suppressed.
【００２８】なお、上記実施例では３種類の材料から成
る屈折光学系１０について説明したが、４種類以上の材
料から成る屈折光学系１０についても同様の効果が得ら
れることは明らかである。In the above embodiment, the refractive optical system 10 made of three types of materials has been described. However, it is apparent that the same effect can be obtained with the refractive optical system 10 made of four or more types of materials.
【００２９】また、上記実施例では８〜１２μｍ近辺の
波長の赤外線を集光する赤外線光学装置について説明し
たが、他の波長帯域に用いる光学装置についても同様の
効果が得られることはいうまでもない。In the above embodiment, an infrared optical device for collecting infrared light having a wavelength of about 8 to 12 μm has been described. However, it is needless to say that similar effects can be obtained with optical devices used in other wavelength bands. Absent.
【００３０】実施例２．図３はこの発明の実施例２を示
す赤外線光学装置の構成断面図である。図中、１〜４，
１２，２０は上記実施例１と同一のものであり、１０は
１枚のレンズで代表して表した屈折光学系であり、少な
くとも３種類の材料のレンズから成る。反射光学系４で
一度結像しない場合でも、同様の効果が得られることは
いうまでもない。Embodiment 2 FIG. FIG. 3 is a sectional view showing the configuration of an infrared optical device according to a second embodiment of the present invention. In the figure, 1-4
Reference numerals 12 and 20 are the same as those in the first embodiment, and reference numeral 10 is a refractive optical system represented by one lens, which is composed of lenses of at least three types of materials. It goes without saying that the same effect can be obtained even when no image is formed by the reflection optical system 4 once.
【００３１】[0031]
【発明の効果】以上のようなこの発明によれば、少なく
とも３種類の材料から成る屈折光学系を構成して色収差
と熱収差とを補正することにより、色収差と熱収差によ
る解像度の劣化を小さく抑えた赤外線光学装置を得るこ
とができる。According to the present invention as described above, a refractive optical system composed of at least three kinds of materials is configured to correct chromatic aberration and thermal aberration, thereby reducing degradation of resolution due to chromatic aberration and thermal aberration. A suppressed infrared optical device can be obtained.
【図１】この発明の実施例１を示す赤外線光学装置の構
成断面図である。FIG. 1 is a cross-sectional view illustrating a configuration of an infrared optical device according to a first embodiment of the present invention.
【図２】図２（ａ）は図１の赤外線光学装置のＭＴＦを
示す特性図、図２（ｂ）は温度変化に対する結像位置の
移動量を示す特性図である。2A is a characteristic diagram showing an MTF of the infrared optical device of FIG. 1, and FIG. 2B is a characteristic diagram showing a moving amount of an imaging position with respect to a temperature change.
【図３】この発明の実施例２を示す赤外線光学装置の構
成断面図である。FIG. 3 is a sectional view of the configuration of an infrared optical device according to a second embodiment of the present invention.
【図４】従来の赤外線光学装置を示す構成断面図であ
る。FIG. 4 is a sectional view showing the configuration of a conventional infrared optical device.
【図５】従来の赤外線光学装置を説明するための説明図
である。FIG. 5 is an explanatory diagram for explaining a conventional infrared optical device.
【図６】代表的な赤外線透過材料の特性図である。FIG. 6 is a characteristic diagram of a typical infrared transmitting material.
１ ドーム ２ 第１の反射鏡 ３ 第２の反射鏡 ４ 反射光学系 ５〜９ 屈折光学系 １０ 屈折光学系 １１ 絞り １２ 検出器 ２０ 入射赤外線 DESCRIPTION OF SYMBOLS 1 Dome 2 1st reflection mirror 3 2nd reflection mirror 4 Reflection optical system 5-9 Refraction optical system 10 Refraction optical system 11 Aperture 12 Detector 20 Incident infrared rays
フロントページの続き (56)参考文献 特開 平２−79809（ＪＰ，Ａ) 特開 昭61−132901（ＪＰ，Ａ) 特開 昭58−219515（ＪＰ，Ａ) 特開 平２−157623（ＪＰ，Ａ) 特開 平３−63535（ＪＰ，Ａ) 実開 平３−130519（ＪＰ，Ｕ) 米国特許4431917（ＵＳ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) G01J 1/02 - 1/04 G01J 5/08 G01V 9/04 H04N 5/33 - 5/335 G02B 13/14 Continuation of the front page (56) References JP-A-2-79809 (JP, A) JP-A-61-132901 (JP, A) JP-A-58-219515 (JP, A) JP-A-2-157623 (JP) JP-A-3-63535 (JP, A) JP-A-3-130519 (JP, U) US Patent 4,431,917 (US, A) (58) Fields investigated (Int. Cl. 7 , DB name) G01J 1/02-1/04 G01J 5/08 G01V 9/04 H04N 5/33-5/335 G02B 13/14
Claims (1)
反射光学系と、屈折光学系と、検出器とで構成する光学
装置において、 上記入射赤外線を上記検出器へ入射させる屈折光学系と
して、ｉを１ないしｎまでの任意の番号として、ｆをレ
ンズの焦点距離、Ｖをレンズ材料のアッベ数、Ｖ T をレ
ンズ材料の熱アッベ数、Ｔを温度とするとき、 を概略、同時に満足するゲルマニウムを含む合計３種類
以上の材料を用いたことを特徴とする赤外線光学装置。1. An optical device comprising a reflection optical system for collecting incident infrared light from an object to be imaged, a refractive optical system, and a detector, wherein the refractive optical system for making the incident infrared light incident on the detector is provided. , I is any number from 1 to n, and f is
The focal length of the lens, the Abbe number of the V lens material, the V T Le
The thermal Abbe number of the material An infrared optical device characterized by using a total of three or more types of materials containing germanium that satisfy simultaneously .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04690092A JP3168221B2 (en) | 1992-03-04 | 1992-03-04 | Infrared optical device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04690092A JP3168221B2 (en) | 1992-03-04 | 1992-03-04 | Infrared optical device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05248942A JPH05248942A (en) | 1993-09-28 |
| JP3168221B2 true JP3168221B2 (en) | 2001-05-21 |
Family
ID=12760244
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04690092A Expired - Lifetime JP3168221B2 (en) | 1992-03-04 | 1992-03-04 | Infrared optical device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3168221B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008216765A (en) * | 2007-03-06 | 2008-09-18 | Technical Research & Development Institute Ministry Of Defence | Infrared optical system and device |
-
1992
- 1992-03-04 JP JP04690092A patent/JP3168221B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05248942A (en) | 1993-09-28 |
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