JP3489379B2 - Infrared imaging device - Google Patents
Infrared imaging deviceInfo
- Publication number
- JP3489379B2 JP3489379B2 JP04811997A JP4811997A JP3489379B2 JP 3489379 B2 JP3489379 B2 JP 3489379B2 JP 04811997 A JP04811997 A JP 04811997A JP 4811997 A JP4811997 A JP 4811997A JP 3489379 B2 JP3489379 B2 JP 3489379B2
- Authority
- JP
- Japan
- Prior art keywords
- infrared
- window
- axis
- optical system
- entrance pupil
- 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
- 238000003331 infrared imaging Methods 0.000 title claims description 15
- 230000003287 optical effect Effects 0.000 claims description 43
- 210000001747 pupil Anatomy 0.000 claims description 31
- 241000234479 Narcissus Species 0.000 description 12
- 238000001514 detection method Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 230000006866 deterioration Effects 0.000 description 4
- 230000005855 radiation Effects 0.000 description 1
Landscapes
- Transforming Light Signals Into Electric Signals (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
- Instruments For Viewing The Inside Of Hollow Bodies (AREA)
Description
【発明の詳細な説明】
【０００１】
【発明の属する技術分野】この発明は、外部環境から赤
外線光学系、赤外線画像検出器を保護するために球面の
一部よりなる赤外窓と、広視野角かつ入射瞳径が赤外窓
の曲率半径に対して十分小さい赤外線光学系を有する赤
外線撮像装置に関するものである。
【０００２】
【従来の技術】図３は、従来の球面の一部よりなる赤外
窓を有する赤外線撮像装置の構成図である。図におい
て、１は球面の一部よりなる赤外窓、２は赤外線光学
系、３は赤外線画像検出器、４は赤外線検出素子、５は
コールドシールド、６はデュワ、７は冷却機、８は赤外
線光学系光軸、９は軸上赤外線光線、１０は軸外赤外線
光線、１１は赤外窓の反射で見る軸上赤外線光線、１２
は赤外窓の反射で見る軸外赤外線光線１３は入射瞳、１
４は赤外線光学系半視野角θ、１５は入射瞳径Ｄ、１６
は赤外窓の曲率半径Ｒ、１７は赤外窓の球心、１８は入
射瞳中心である。
【０００３】次に動作について説明する。赤外線光学系
光軸８の方向から入射した軸上赤外線光線９および軸外
赤外線光線１０は球面の一部よりなる赤外窓１を透過
し、入射瞳１３を通過するように赤外線光学系２に入射
し、コールドシールド５を経て赤外線検出素子４上に集
光される。赤外線検出素子４の出力信号は、赤外線画像
検出器３により画像信号に変換され外部に出力される。
【０００４】球面の一部よりなる赤外窓１は、外部環境
から赤外線光学系２、赤外線画像検出器３を守るために
必須なものである。コールドシールド５は、赤外線検出
素子４に不要な赤外線光が入射することを防ぐために必
須なものであり、赤外線検出素子４とともに冷却機７に
より例えば８０Ｋ以下に冷却される。
【０００５】
【発明が解決しようとする課題】上記のような従来の赤
外線撮像装置は球面の一部よりなる赤外窓１の反射によ
り、赤外線検出素子４の軸上周辺と、赤外線検出器半視
野角θ１４付近の軸外では赤外線検出素子４が見る部分
の温度が異なる。入射瞳径Ｄ１５が赤外窓の曲率半径Ｒ
１６に対して小さく、例えば入射瞳径Ｄ１５が赤外窓の
曲率半径Ｒ１６の１０分の１以下の場合、球面の一部よ
りなる赤外窓１は入射瞳径Ｄ１５の範囲内ではほぼ平面
と見なすことができる。このため、赤外窓１の反射で見
る軸上赤外線光線１１は、軸上赤外線光線９と逆の光路
をたどることになり、赤外線検出素子４の軸上周辺は冷
却された赤外線検出素子４自身を見ることになる。一方
赤外窓１の反射で見る軸外赤外線光線１２は、赤外線光
学系２の入射瞳１３を通過しないため、赤外線検出素子
４の軸外周辺は冷却された赤外線検出素子４及びコール
ドシールド５以外の常温部分を見ることになる。赤外線
撮像装置は、物体の放射温度の差を輝度の差として画像
化するため、上記のように見る部分の温度が異なる場
合、画像に輝度分布を持つことになり、画像を表示した
際中央部で低温、周辺部で高温として表示されるナルシ
サスという現象が発生する。ナルシサスが発生した場
合、均一な目標を赤外線撮像装置で画像化しても、画像
は均一な温度として表示されないため、ナルシサスは画
質劣化の要因となる。
【０００６】赤外線光学系半視野角θ１４が小さい場合
は、平面形状の赤外窓を使用して、平面形状の赤外窓を
赤外線光軸８に対して傾けることにより、赤外窓の反射
で見る軸上赤外線光１１及び赤外窓の反射で見る軸外赤
外線光１２がともに冷却された赤外線検出器４及びコー
ルドシールド５以外の常温部分から発するようにして、
ナルシサスの発生を抑えることができるが、赤外線光学
系半視野角θ１４が例えば３０度を越えるような広視野
角の場合は、平面形状の赤外窓は大型化するため搭載寸
法に制限がある機器での使用は困難であり、小型化のた
めには球面の一部よりなる赤外窓１を用いる必要があ
り、ナルシサスの発生を避けることができなかった。
【０００７】この発明はかかる問題点を解決するために
なされたものであり、赤外線光学系の半視野角θ１４が
広角で入射瞳径Ｄ１５が球面の一部よりなる赤外窓の曲
率半径に対して十分に小さい場合において、球面の一部
よりなる赤外窓１により、ナルシサスによる画像の劣化
のない赤外線撮像装置を得ることを目的としている。
【０００８】
【０００９】【課題を解決するための手段】この
発明の赤外線撮像装
置は、赤外窓の曲率半径Ｒと、赤外窓の球心を原点とし
赤外線光学系の光軸と平行な方向にＸ軸をとり、赤外線
光学系の入射瞳位置を含む面内でＸ軸に垂直な方向にＹ
軸をとった場合の赤外線光学系の入射瞳中心の位置座標
（ｘ、ｙ）、入射瞳面上に投影されたコールドシールド
の径をＡ’、赤外線光学系の半視野角をθとしたとき、
次式の関係がなりたつ赤外窓を配置したものである。
【００１０】
【数２】
【００１１】
【発明の実施の形態】
実施の形態１．図１はこの発明の実施の形態１を示す構
成図であり、図において、１は球面の一部よりなる赤外
窓、２は赤外線光学系、３は赤外線画像検出器、４は赤
外線検出素子、５はコールドシールド、６はデュワ、７
は冷却機、８は赤外線光学系光軸、９は軸上赤外線光
線、１０は軸外赤外線光線、１１は赤外窓の反射で見る
軸上赤外線光線、１２は赤外窓の反射で見る軸外赤外線
光線、１３は入射瞳、１４は赤外線光学系半視野角θ、
１５は入射瞳径Ｄ、１６は赤外窓の曲率半径Ｒ、１７は
赤外窓の球心、１８は入射瞳中心である。
【００１２】この発明による赤外線撮像装置は上記のよ
うに構成され、以下のように動作する。赤外線光学系光
軸８の方向から入射した軸上赤外線光線９は球面の一部
よりなる赤外窓１を透過し、赤外線光学系２を通過し、
コールドシールド５を経て赤外線検出素子４上に集光さ
れる。赤外線検出素子４の出力は、赤外線画像検出器３
により画像信号に変換され外部に出力される。軸上赤外
線光９、および軸外赤外線光１０は見かけ上入射瞳１３
上で一致する。一方、球面の一部よりなる赤外窓１の表
面の反射により赤外線検出素子４が見る領域は、赤外窓
１の球心１７と入射瞳中心１８が一致しているため、軸
上赤外線光線９及び軸外赤外線光線１０ともに球面の一
部よりなる赤外窓１はそれぞれの赤外窓の反射による赤
外線光線に対して正対していることになり、赤外窓の反
射で見る軸上赤外線光線１１と赤外窓１の反射で見る軸
外赤外線光線１２はともに、軸上赤外線光線９及び軸外
赤外線光線１０と逆の光路をたどることになり、すなわ
ち冷却された赤外線検出素子４自身を見ることになる。
なおこのとき、赤外窓の曲率半径Ｒ１６は入射瞳径Ｄ１
５に対して十分に大きいため、球面の一部よりなる赤外
窓１は入射瞳径Ｄ１５内においてほぼ平面と見なせる。
つまり、球面の一部よりなる赤外窓１の表面の反射によ
り赤外線検出素子４が見る領域は、赤外線検出素子４全
面の冷却された領域であり、見る物体の温度差に起因す
るナルシサスの発生は防ぐことができ、ナルシサスによ
る画像の質の劣化がない。
【００１３】実施の形態２．図２はこの発明の実施の形
態２を示す構成図であり、図２において、１から１８は
実施の形態の１と同じ機能を有する部品、１９はコール
ドシールドの径Ａ、２０は入射瞳面上に投影されたコー
ルドシールド像、２１は入射瞳面上に投影されたコール
ドシールド像の径Ａ’、２２はＸ軸、２３はＹ軸であ
る。
【００１４】この発明による赤外線撮像装置は上記のよ
うに構成され、以下のように動作する。赤外線光学系光
軸８の方向から入射した軸上赤外線光線９は球面の一部
よりなる赤外窓１を透過し、赤外線光学系２を通過し、
コールドシールド５を経て赤外線検出素子４上に集光さ
れる。赤外線検出素子４の出力は、赤外線画像検出器３
により画像信号に変換され外部に出力される。軸上赤外
線光９、および軸外赤外線光１０は見かけ上入射瞳１３
上で一致する。一方、赤外窓１の球心１７を原点とし、
Ｘ軸２２を赤外線光学系光軸８と平行な方向にとり、Ｙ
軸２３を入射瞳中心１８を含む面内でＸ軸２２と直交す
るようにとった場合の、入射瞳中心１８のＸ座標をｘ、
Ｙ座標をｙとし、赤外窓の曲率半径Ｒ１８と入射瞳面上
に投影されたコールドシールド像の径Ａ’２１とする
と、次式の関係を満たすことにより、赤外窓の反射で見
る軸上赤外線光線１１及び赤外窓の反射で見る軸外赤外
線光線１２はともに、入射瞳面上に投影されたコールド
シールド像２２を通過しない。
【００１５】
【数３】
【００１６】このため、赤外窓１の反射で見る軸上赤外
線光線１１と赤外窓１の反射で見る軸外赤外線光線１２
はともに、赤外線検出素子４及びコールドシールド５以
外から発することになる。なおこのとき、赤外窓１の曲
率半径Ｒ１６は入射瞳径Ｄ１５に対して十分に大きいた
め、球面の一部よりなる赤外窓１は入射瞳径Ｄ１６内に
おいてほぼ平面と見なせる。つまり、球面の一部よりな
る赤外窓１の表面反射により赤外線検出素子４が見る領
域は、赤外線検出素子４全面で冷却されていない領域で
あり、見る物体の温度差に起因するナルシサスの発生は
防ぐことができ、ナルシサスによる画質の劣化がない。
【００１７】
【００１８】【発明の効果】この
発明によれば、球面の一部からなる
赤外窓の球心と曲率半径と、赤外線光学系の入射瞳中心
の位置と入射瞳面上に投影されたコールドシールド像の
径と半視野角について（１）式の関係を満たすことによ
り、ナルシサスの発生をなくしナルシサスによる画質の
劣化のない画像を得ることができる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared window comprising a part of a spherical surface for protecting an infrared optical system and an infrared image detector from an external environment, and a wide field of view. The present invention relates to an infrared imaging apparatus having an infrared optical system whose angle and entrance pupil diameter are sufficiently smaller than the radius of curvature of an infrared window. 2. Description of the Related Art FIG. 3 is a configuration diagram of a conventional infrared imaging apparatus having an infrared window formed by a part of a spherical surface. In the figure, 1 is an infrared window composed of a part of a spherical surface, 2 is an infrared optical system, 3 is an infrared image detector, 4 is an infrared detecting element, 5 is a cold shield, 6 is a Dewar, 7 is a cooler, and 8 is Infrared optical system optical axis, 9 is on-axis infrared ray, 10 is off-axis infrared ray, 11 is on-axis infrared ray seen by reflection of infrared window, 12
Is the off-axis infrared ray 13 seen from the reflection of the infrared window.
4 is an infrared optical system half-viewing angle θ, 15 is an entrance pupil diameter D, 16
Is the radius of curvature R of the infrared window, 17 is the spherical center of the infrared window, and 18 is the center of the entrance pupil. Next, the operation will be described. The on-axis infrared ray 9 and the off-axis infrared ray 10 incident from the direction of the optical axis 8 of the infrared optical system pass through the infrared window 1 formed of a part of the spherical surface and pass through the entrance pupil 13 to the infrared optical system 2. The light enters and is focused on the infrared detecting element 4 through the cold shield 5. The output signal of the infrared detecting element 4 is converted into an image signal by the infrared image detector 3 and output to the outside. [0004] An infrared window 1 consisting of a part of a spherical surface is essential for protecting the infrared optical system 2 and the infrared image detector 3 from the external environment. The cold shield 5 is essential for preventing unnecessary infrared light from entering the infrared detection element 4, and is cooled together with the infrared detection element 4 to, for example, 80 K or less by the cooler 7. [0005] The above-described conventional infrared imaging apparatus as described above reflects an infrared window 1 formed of a part of a spherical surface, and thereby, an axial periphery of the infrared detecting element 4 and a half of the infrared detector. Outside the axis near the viewing angle θ14, the temperature of the portion viewed by the infrared detection element 4 differs. The entrance pupil diameter D15 is equal to the radius of curvature R of the infrared window.
16, for example, when the entrance pupil diameter D15 is 1/10 or less of the radius of curvature R16 of the infrared window, the infrared window 1 composed of a part of the spherical surface is substantially flat within the range of the entrance pupil diameter D15. Can be considered. For this reason, the axial infrared ray 11 viewed by the reflection of the infrared window 1 follows an optical path opposite to that of the axial infrared ray 9, and the axial periphery of the infrared detecting element 4 is cooled by the cooled infrared detecting element 4 itself. You will see. On the other hand, the off-axis infrared ray 12 viewed by the reflection of the infrared window 1 does not pass through the entrance pupil 13 of the infrared optical system 2, so that the off-axis periphery of the infrared detection element 4 is other than the cooled infrared detection element 4 and the cold shield 5. You will see the room temperature section. Since the infrared imaging device images the difference in the radiation temperature of the object as the difference in luminance, if the temperature of the part to be viewed is different as described above, the image will have a luminance distribution, and when the image is displayed, the central part will be displayed. , A phenomenon called narcissus, which is displayed as a low temperature and a high temperature in the periphery, occurs. When narcissus occurs, even if a uniform target is imaged by an infrared imaging device, the image is not displayed as a uniform temperature, so that narcissus causes image quality deterioration. When the infrared optical system has a small half-viewing angle θ14, a flat infrared window is used to tilt the flat infrared window with respect to the infrared optical axis 8 so that the infrared window reflects light. Both the on-axis infrared light 11 to be viewed and the off-axis infrared light 12 to be viewed by reflection from the infrared window are emitted from the room temperature portion other than the cooled infrared detector 4 and cold shield 5,
Although it is possible to suppress the occurrence of narcissus, if the infrared optical system has a wide viewing angle such that the half viewing angle θ14 exceeds, for example, 30 degrees, the planar infrared window becomes large and the mounting size is limited. However, it is necessary to use an infrared window 1 formed of a part of a spherical surface for downsizing, and the occurrence of narcissus cannot be avoided. The present invention has been made to solve such a problem. The infrared optical system has a wide half-viewing angle θ14 and a large entrance pupil diameter D15 with respect to the radius of curvature of an infrared window formed of a part of a spherical surface. It is an object of the present invention to obtain an infrared imaging apparatus in which the image is not deteriorated by narcissus by the infrared window 1 which is a part of the spherical surface when the image is sufficiently small. An infrared imaging apparatus according to the present invention has a radius of curvature R of an infrared window and a center of origin of a spherical center of the infrared window, which is parallel to an optical axis of an infrared optical system. In the direction including the entrance pupil position of the infrared optical system and the Y axis in the direction perpendicular to the X axis.
Position coordinates (x, y) of the center of the entrance pupil of the infrared optical system when the axes are taken, A 'is the diameter of the cold shield projected on the entrance pupil plane, and θ is the half viewing angle of the infrared optical system ,
An infrared window having the following relationship is arranged. [0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a block diagram showing Embodiment 1 of the present invention. In the drawing, reference numeral 1 denotes an infrared window composed of a part of a spherical surface, 2 denotes an infrared optical system, 3 denotes an infrared image detector, and 4 denotes an infrared detection element. 5, cold shield, 6 dewar, 7
Is a cooler, 8 is an optical axis of an infrared optical system, 9 is an on-axis infrared ray, 10 is an off-axis infrared ray, 11 is an on-axis infrared ray viewed by reflection of an infrared window, and 12 is an axis viewed by reflection of an infrared window. External infrared ray, 13 is an entrance pupil, 14 is an infrared optical system half viewing angle θ,
15 is an entrance pupil diameter D, 16 is a radius of curvature R of the infrared window, 17 is a spherical center of the infrared window, and 18 is a center of the entrance pupil. The infrared imaging apparatus according to the present invention is configured as described above and operates as follows. An axial infrared ray 9 incident from the direction of the optical axis 8 of the infrared optical system passes through the infrared window 1 formed of a part of the spherical surface, passes through the infrared optical system 2,
The light is focused on the infrared detecting element 4 through the cold shield 5. The output of the infrared detecting element 4 is the infrared image detector 3
Is converted into an image signal and output to the outside. The on-axis infrared light 9 and off-axis infrared light 10 apparently enter the entrance pupil 13.
Matches above. On the other hand, the region viewed by the infrared detecting element 4 due to the reflection of the surface of the infrared window 1 which is a part of the spherical surface, because the spherical center 17 of the infrared window 1 coincides with the center of the entrance pupil 18, Both the infrared window 9 and the off-axis infrared ray 10 have a part of the spherical surface, and the infrared window 1 is directly opposed to the infrared ray reflected by each infrared window. Both the light beam 11 and the off-axis infrared light beam 12 viewed from the reflection of the infrared window 1 follow the optical paths opposite to the on-axis infrared light beam 9 and the off-axis infrared light beam 10, that is, the cooled infrared detecting element 4 itself. You will see.
At this time, the radius of curvature R16 of the infrared window is the entrance pupil diameter D1.
5, the infrared window 1 formed by a part of the spherical surface can be regarded as substantially flat within the entrance pupil diameter D15.
In other words, the area that the infrared detecting element 4 sees due to the reflection of the surface of the infrared window 1 that is a part of the spherical surface is a cooled area of the entire surface of the infrared detecting element 4, and the occurrence of narcissus due to the temperature difference of the object to be viewed. Can be prevented, and there is no deterioration in image quality due to narcissus. Embodiment 2 FIG. FIG. 2 is a block diagram showing a second embodiment of the present invention. In FIG. 2, 1 to 18 are components having the same function as in the first embodiment, 19 is a diameter A of a cold shield, and 20 is an entrance pupil plane. The cold shield image projected above, 21 is the diameter A 'of the cold shield image projected on the entrance pupil plane, 22 is the X axis, and 23 is the Y axis. The infrared imaging device according to the present invention is configured as described above and operates as follows. An axial infrared ray 9 incident from the direction of the optical axis 8 of the infrared optical system passes through the infrared window 1 formed of a part of the spherical surface, passes through the infrared optical system 2,
The light is focused on the infrared detecting element 4 through the cold shield 5. The output of the infrared detecting element 4 is the infrared image detector 3
Is converted into an image signal and output to the outside. The on-axis infrared light 9 and off-axis infrared light 10 apparently enter the entrance pupil 13.
Matches above. On the other hand, with the spherical center 17 of the infrared window 1 as the origin,
The X axis 22 is set in a direction parallel to the optical axis 8 of the infrared optical system,
When the axis 23 is set to be orthogonal to the X axis 22 in the plane including the entrance pupil center 18, the X coordinate of the entrance pupil center 18 is x,
Assuming that the Y coordinate is y, the radius of curvature R18 of the infrared window and the diameter A'21 of the cold shield image projected on the entrance pupil plane, the axis seen by the reflection of the infrared window is satisfied by satisfying the following expression. Neither the upper infrared ray 11 nor the off-axis infrared ray 12 viewed from the reflection of the infrared window passes through the cold shield image 22 projected on the entrance pupil plane. [Equation 3] For this reason, the on-axis infrared ray 11 seen by the reflection of the infrared window 1 and the off-axis infrared ray 12 seen by the reflection of the infrared window 1
Are emitted from other than the infrared detecting element 4 and the cold shield 5. At this time, since the radius of curvature R16 of the infrared window 1 is sufficiently large with respect to the entrance pupil diameter D15, the infrared window 1 formed by a part of the spherical surface can be regarded as substantially flat within the entrance pupil diameter D16. In other words, the area that the infrared detecting element 4 sees due to the surface reflection of the infrared window 1 that is a part of the spherical surface is an area that is not cooled on the entire surface of the infrared detecting element 4, and the occurrence of narcissus due to the temperature difference of the object to be viewed. Can be prevented, and there is no deterioration in image quality due to narcissus. According to the present invention, the spherical center and the radius of curvature of the infrared window, which is a part of the spherical surface, the position of the center of the entrance pupil of the infrared optical system, and the projection on the entrance pupil plane. By satisfying the relationship of the expression (1) with respect to the diameter and the half-viewing angle of the obtained cold shield image, it is possible to eliminate the occurrence of narcissus and obtain an image without image quality deterioration due to narcissus.
【図面の簡単な説明】
【図１】 この発明による赤外線撮像装置の実施の形態
の１を示す図である。
【図２】 この発明による赤外線撮像装置の実施の形態
の２を示す図である。
【図３】 従来の赤外線撮像装置を示す図である。
【符号の説明】
１ 球面の一部よりなる赤外窓、２ 赤外線光学系、３
赤外線画像検出器、４ 赤外線検出素子、５ コール
ドシールド、６ デュワ、７ 冷却機、８ 赤外線光学
系光軸。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a first embodiment of an infrared imaging device according to the present invention. FIG. 2 is a diagram showing a second embodiment of the infrared imaging device according to the present invention; FIG. 3 is a diagram showing a conventional infrared imaging device. [Explanation of Signs] 1. Infrared window consisting of a part of spherical surface, 2. Infrared optical system, 3.
Infrared image detector, 4 infrared detector, 5 cold shield, 6 dewar, 7 cooler, 8 infrared optical system optical axis.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ Ｈ０４Ｎ 5/33 Ｈ０４Ｎ 5/33 (58)調査した分野(Int.Cl.7，ＤＢ名) G01J 1/02 - 1/06 G01J 1/42 - 1/44 G01J 5/02 G01J 5/08 G01J 5/48 G01V 9/04 G02B 23/24 G03B 41/00 H04N 5/225 H04N 5/30 - 5/335 ──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. 7 identification symbol FI H04N 5/33 H04N 5/33 (58) Investigated field (Int.Cl. 7 , DB name) G01J 1/02-1/06 G01J 1/42-1/44 G01J 5/02 G01J 5/08 G01J 5/48 G01V 9/04 G02B 23/24 G03B 41/00 H04N 5/225 H04N 5/30-5/335
Claims (1)
球面の一部よりなる赤外窓と、この赤外窓を透過した赤
外線を赤外線画像検出器内部の冷却された赤外線受光素
子に結像させる赤外線光学系とを具備した赤外線撮像装
置において、前記球面の一部よりなる赤外窓の曲率半径
Ｒと、前記球面の一部よりなる赤外窓の曲率中心を原点
とし前記赤外線光学系の光軸と平行な方向にＸ軸をと
り、前記赤外線光学系の入射瞳位置を含む面内でＸ軸に
直交するようＹ軸をとった場合の前記赤外線光学系の入
射瞳中心の位置座標（ｘ、ｙ）、入射瞳面上に投影され
たコールドシールド像の径をＡ’、前記赤外線光学系の
半視野角をθとしたとき、上記赤外窓は“数１”の関係
が成立する赤外窓であることを特徴とする赤外線撮像装
置。 【数１】 (57) [Claims 1] Transmit infrared rays emitted from a target,
An infrared imaging apparatus comprising: an infrared window including a part of a spherical surface; and an infrared optical system configured to form an infrared ray transmitted through the infrared window onto a cooled infrared light receiving element inside an infrared image detector. And the X axis is taken in the direction parallel to the optical axis of the infrared optical system with the origin being the center of curvature of the infrared window consisting of a part of the spherical surface and the radius of curvature of the infrared window consisting of a part of the spherical surface. Position coordinates (x, y) of the center of the entrance pupil of the infrared optical system when the Y axis is taken so as to be orthogonal to the X axis in a plane including the entrance pupil position of the system, a cold shield projected on the entrance pupil plane The infrared imaging apparatus is characterized in that when the diameter of the image is A ′ and the half viewing angle of the infrared optical system is θ, the infrared window is an infrared window that satisfies the relationship of “Equation 1”. (Equation 1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04811997A JP3489379B2 (en) | 1997-03-03 | 1997-03-03 | Infrared imaging device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04811997A JP3489379B2 (en) | 1997-03-03 | 1997-03-03 | Infrared imaging device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10246668A JPH10246668A (en) | 1998-09-14 |
| JP3489379B2 true JP3489379B2 (en) | 2004-01-19 |
Family
ID=12794450
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04811997A Expired - Lifetime JP3489379B2 (en) | 1997-03-03 | 1997-03-03 | Infrared imaging device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3489379B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7002154B2 (en) * | 2003-04-25 | 2006-02-21 | Raytheon Company | Optical system for a wide field of view staring infrared sensor having improved optical symmetry |
-
1997
- 1997-03-03 JP JP04811997A patent/JP3489379B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH10246668A (en) | 1998-09-14 |
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