JPS62164010A - Infrared ray camera - Google Patents
Infrared ray cameraInfo
- Publication number
- JPS62164010A JPS62164010A JP61005054A JP505486A JPS62164010A JP S62164010 A JPS62164010 A JP S62164010A JP 61005054 A JP61005054 A JP 61005054A JP 505486 A JP505486 A JP 505486A JP S62164010 A JPS62164010 A JP S62164010A
- Authority
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- Japan
- Prior art keywords
- mirror
- small
- concave mirror
- plane
- focal point
- 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.)
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- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
- Radiation Pyrometers (AREA)
- Lenses (AREA)
Abstract
Description
【発明の詳細な説明】
発明の目的
(産業上の利用分野)
この発明は赤外線カメラ、特に回転2次曲面反射鏡を用
いた光学系を有する平面ミラー対物面走査方式の赤外線
カメラに関する。DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to an infrared camera, and particularly to a plane mirror object plane scanning type infrared camera having an optical system using a rotating quadratic curved reflector.
(従来技術)
平面ミラー対物面走査方式の赤外線カメラは、建造物の
壁診断用等の目的に使用されており、その構成は第14
図に示される。すなわち、カメラ1内へ入射窓2から入
射した赤外線は走査鏡3で偏向され、集光レンズ4、リ
レーレンズ5によって検知器6に集光される。一方、カ
メラ内には基準熱源7が配設され、該熱源からの赤外線
はレンズ8で集光レンズ4の集光位置に集光される。こ
の集光位置にはチョッパ反射鏡9が挿脱され、検知器に
入射する赤外光を被写体からのものと基準熱源からのも
のとの切り換えを行う。(Prior art) An infrared camera using a plane mirror object plane scanning method is used for purposes such as diagnosing walls of buildings, and its configuration is as follows.
As shown in the figure. That is, infrared rays entering the camera 1 through the entrance window 2 are deflected by the scanning mirror 3 and focused onto the detector 6 by the condensing lens 4 and the relay lens 5. On the other hand, a reference heat source 7 is disposed within the camera, and infrared rays from the heat source are focused by a lens 8 onto a focusing position of the focusing lens 4. A chopper reflector 9 is inserted into and removed from this light collection position, and switches the infrared light incident on the detector between that from the object and that from the reference heat source.
このような光学系においては、検知器6は常に光学系の
光軸上にある物体のみを検知している。In such an optical system, the detector 6 always detects only objects located on the optical axis of the optical system.
従って光学系は物体高0の被写体に対してのみ十分な収
差補正が行われていればよいこととなり、光学設計には
有利な条件となる。実際には検知器の検知部の面積が0
ではないので、その面積に対応する被写体の大きさを考
慮しなければならないが、実用化されている検知器では
検知部の大きさは直径0.1m以下であり、上記の有利
さに影響を与える程のものではない。Therefore, the optical system only needs to perform sufficient aberration correction for a subject whose object height is 0, which is an advantageous condition for optical design. In reality, the area of the detection part of the detector is 0.
Therefore, it is necessary to consider the size of the object corresponding to the area, but in the detectors in practical use, the size of the detection part is less than 0.1 m in diameter, which has no effect on the above advantages. It's not worth giving.
(この発明が解決しようとする問題点)建造物の壁診断
用赤外線カメラの場合、波長10μm程度の赤外線を検
知するのが最もよいとされているが、この程度の波長の
赤外線を透過させる光学材料は非常に少なく、一般には
材料自体が高価であるゲルマニュームが用いられる。そ
の上ゲルマニュームの屈折率は約4であり、表面反射率
も非常に高いものとなる。そのため、これをレンズとし
て用いる場合1反射防止コーティングをする必要がある
が、コーティング層の厚さも透過赤外線の波長に合わせ
て2〜3μmと可視光領域では考えられない厚さにしな
ければならず、この点でもコスト高を免れない。(Problem to be solved by this invention) In the case of an infrared camera for diagnosing walls of buildings, it is said that it is best to detect infrared rays with a wavelength of about 10 μm. There are very few materials used, and germanium, which is an expensive material itself, is generally used. Furthermore, the refractive index of germanium is approximately 4, and the surface reflectance is also very high. Therefore, when using this as a lens, it is necessary to apply an anti-reflection coating, but the thickness of the coating layer must also be 2 to 3 μm, which is unthinkable in the visible light region, in accordance with the wavelength of the transmitted infrared rays. In this respect as well, high costs cannot be avoided.
また、検出器の感度や検出信号のS/N比の改善のため
に十分な赤外線エネルギーを入射させようとすれば、口
径40mm程度のレンズが必要となる。材料の使用量は
単純に云えば口径の3乗に比例することとなり、口径が
2倍になれば使用量は8倍となり、使用レンズの口径を
大きくすればゲルマニューム材料が高価なためレンズの
コストアップを招く。Furthermore, in order to inject sufficient infrared energy to improve the sensitivity of the detector and the S/N ratio of the detection signal, a lens with an aperture of about 40 mm is required. Simply put, the amount of material used is proportional to the cube of the aperture, so if the aperture doubles, the amount used will increase eight times, and if the aperture of the lens is increased, the cost of the lens will decrease because germanium material is expensive. Invite up.
発明の構成
(問題を解決するための手段)
この発明においては、集光光学系として回転2次曲面反
射鏡を用いることにより、従来のようなレンズ材料の制
約を受けない赤外線カメラを得ようとするものである。Structure of the Invention (Means for Solving the Problem) This invention attempts to obtain an infrared camera that is not subject to the limitations of conventional lens materials by using a rotating quadratic curved reflector as a condensing optical system. It is something to do.
すなわち、回転楕円面あるいは回転放物面からなる第1
凹面鏡とこれに対向する回転2次曲面鏡からなる第2の
小鏡を含み、これらの両反射鏡はその焦点を共有し、第
2の小鏡で反射された赤外線の集束点近傍に検知器を配
置する。In other words, the first ellipsoid or paraboloid of revolution
It includes a second small mirror consisting of a concave mirror and a rotating quadratic curved mirror opposing it, and both of these reflecting mirrors share their focal point, and a detector is located near the focal point of the infrared rays reflected by the second small mirror. Place.
第2小鏡が凹面鏡である場合は、両凹面鏡は上記共有焦
点を通る平面に対して互いに逆側に配置される。When the second small mirror is a concave mirror, both concave mirrors are arranged on opposite sides of the plane passing through the shared focal point.
これに対して第2小鏡が凸面鏡である場合はいわゆるカ
セグレン、タイプの光学配置とされ、第1凹面鏡の光軸
部分に孔を設け、第2小鏡からの反射光はこの孔を通っ
て集束することとなる。On the other hand, when the second small mirror is a convex mirror, it is a so-called Cassegrain type optical arrangement, in which a hole is provided at the optical axis of the first concave mirror, and the reflected light from the second small mirror passes through this hole. It will be focused.
また、主として合焦走査を容易にし、結像性能を向上さ
せるため、ゲルマニュームレンズを付加するのが望まし
い。Further, it is desirable to add a germanium lens mainly to facilitate focusing scanning and improve imaging performance.
(実施例) 以下この発明の実施例を示す。(Example) Examples of this invention will be shown below.
(実施例1)
第1図は、長径を回転軸とする回転楕円面よりなる大小
2個の凹面鏡をそれぞれ一方の焦点を共有させ、凹面が
互いに向き合うように、しかも両凹面鏡は上記共有焦点
を通る一平面で分割される空間の互いに反対側にのみあ
るように配置された例である。(Example 1) Fig. 1 shows two large and small concave mirrors each made of an ellipsoid of revolution with the major axis as the axis of rotation. This is an example in which the space is divided by a single plane, and the space is located only on opposite sides of the space.
第1の大凹面鏡11を入射光側に向け、対物面走査用の
平面ミラー3からの反射光を集光し、小凹面鏡12で検
知器6に被走査点13の像を結ぶ。The first large concave mirror 11 is directed toward the incident light side, and the reflected light from the plane mirror 3 for scanning the object plane is collected, and the small concave mirror 12 forms an image of the scanned point 13 on the detector 6 .
第1図(a)において共有焦点14を原点とする三次元
座標系x、y、zを図のように定め、それぞれ原点14
から2では右、yでは上、Xでは紙面に垂直で裏面に向
かう方向を正とする。このとき両凹面鏡を構成する楕円
の長径方向を2軸と平行もしくはほぼ平行に設定し、大
凹面鏡11は2≦Oおよびy≧0の範囲にのみ存在し、
小凹面鏡12は2≧0およびy≦0の範囲にのみ存在す
るように配設される。回転楕円面鏡においては。In FIG. 1(a), a three-dimensional coordinate system x, y, z with the origin at the shared focal point 14 is defined as shown in the figure, and each point is at the origin 14.
For 2, the right direction, for y, the upward direction, and for X, the direction perpendicular to the page and toward the back is positive. At this time, the long axis direction of the ellipse constituting the biconcave mirror is set parallel or almost parallel to the two axes, and the large concave mirror 11 exists only in the range of 2≦O and y≧0,
The small concave mirror 12 is arranged so that it exists only in the range of 2≧0 and y≦0. In a spheroidal mirror.
一方の焦点から出射する光は無収差で他方の焦点に集束
することはよく知られている。大凹面鏡11の中心と遠
い方の焦点を結ぶ直線を入射側の光軸、軸上光の第2反
射鏡12による反射方向を出射側の光軸とし、これら両
光軸をZ軸に平行に定めた場合の光学配置の概略を第1
図(b)に示す。It is well known that light emitted from one focal point is converged to the other focal point without aberration. The straight line connecting the center of the large concave mirror 11 and the far focal point is the optical axis on the incident side, and the direction in which the on-axis light is reflected by the second reflecting mirror 12 is the optical axis on the output side. Both optical axes are parallel to the Z axis. The outline of the optical arrangement in the case of
Shown in Figure (b).
実際には対物面走査用平面ミラー3で光束が折り曲げら
れ、折り曲げられた光軸上に存在する物体上の点13が
被走査点となり、平面ミラー3の回動走査により物体上
の被走査点が移動するが、図示の簡略化のため省略しで
ある。In reality, the light beam is bent by the object plane scanning plane mirror 3, and a point 13 on the object existing on the bent optical axis becomes the scanned point. moves, but is omitted to simplify the illustration.
上記の光学系において、被走査点13から発散した光束
の1部は大凹面鏡11に入射する。壁診断用赤外線カメ
ラの使用状態では物体距離は一般に3m〜Loom位で
あり、光学系の大きさに較べて十分に大きく、平行光束
に近い発散光となっている。しかし、大凹面鏡11の一
方の焦点を3m〜Loomの距離範囲の何処か一点に採
るとすれば、被走査点がその他の距離にあるときは集束
状態が劣る可能性がある。焦点位置としては最も使用頻
度の高い距離を選んでもよいが、最短被写体距離と最長
被写体距離から関数的に求めてもよい。関数としては、
相加平均、相乗平均などでもよいが、最短、最長面被写
体距離から入射開口を見込む角の平均を取り、この平均
になるような開口角になる距離を選ぶのが最もよい。こ
のような関係を満たす関数は調和平均として知られてお
り、例えば3mと100mの調和平均であれば1/ (
(1/3+1/100) /2) =5.8mとなる。In the above optical system, a portion of the light beam diverging from the scanned point 13 is incident on the large concave mirror 11 . When an infrared camera for wall diagnosis is in use, the object distance is generally about 3 m to 300 m, which is sufficiently large compared to the size of the optical system, and the light is divergent, close to a parallel beam of light. However, if one focal point of the large concave mirror 11 is set at a point somewhere within the distance range of 3 m to 3 m, there is a possibility that the convergence state will be poor if the scanned point is at another distance. The most frequently used distance may be selected as the focal position, but it may also be determined functionally from the shortest subject distance and the longest subject distance. As a function,
An arithmetic mean, a geometric mean, etc. may be used, but it is best to take the average of the angles looking into the entrance aperture from the shortest and longest plane subject distances, and select a distance that will give an aperture angle that is the average. A function that satisfies this relationship is known as a harmonic mean. For example, if the harmonic mean of 3m and 100m is 1/(
(1/3 + 1/100) /2) = 5.8m.
楕円の長径を2a、短径を2b、焦点間距離を20とす
るとき、この発明の、第1反射鏡11の方程式は次式で
表される。When the major axis of the ellipse is 2a, the minor axis is 2b, and the distance between focal points is 20, the equation of the first reflecting mirror 11 of the present invention is expressed by the following equation.
ニジ」位+工L−Cユ
、2 8. =1・・・ (1)a2=b2+
02 ・・・ (2)このとき、楕円反
射鏡の頂点11′と焦点14との距離はa−cで表され
る。また、他の焦点13の2座標はz=2cである。従
って、2cを上記の調和平均にとり、aを与えれば(1
)(2)式から所望の楕円反射鏡の形状を決定すること
が出来る。第2の小凹面鏡12に関しては上記aおよび
Cを負の数で与えれば上記の関係がそのまま成立する。Niji” rank + engineering L-C Yu, 2 8. =1... (1) a2=b2+
02... (2) At this time, the distance between the vertex 11' of the elliptical reflecting mirror and the focal point 14 is represented by a-c. Further, the two coordinates of the other focal point 13 are z=2c. Therefore, if we take 2c to the above harmonic mean and give a, then (1
) The desired shape of the elliptical reflecting mirror can be determined from equation (2). Regarding the second small concave mirror 12, the above relationship holds true if the above a and C are given as negative numbers.
第2図は第1反射鏡の物体側焦点位置をz=2c=7m
+頂点座4jJ z = c −a = −20rm、
小凹面鏡の焦点位置(検知器位置)をz = 2 c
= −20nrn、頂点座標z=c−a=5mm、入射
開口40m角としたときの物体距離100mに対するス
ポットダイヤグラムである。像面位置は−18,432
とした。(a)、(b)、(c)はそれぞれ物点座標(
0,0)、(50nwn、、 50 nun )、(5
0mm 、−50mm)に対応する。空間周波数5c/
mmのMTFは(a)でX方向94.2%、X方向88
.0%、(b)でX方向83.7%、X方向84.4%
、(c)でX方向89.4%、X方向90.6%であっ
た。壁診断用カメラとして必要なMFTは80%程度と
言われているので、上記の値はこれを満足している。Figure 2 shows the object side focus position of the first reflecting mirror at z=2c=7m.
+ Vertex seat 4jJ z = c - a = -20rm,
The focal position (detector position) of the small concave mirror is z = 2 c
This is a spot diagram for an object distance of 100 m when = -20nrn, vertex coordinates z = ca = 5 mm, and an incident aperture of 40 m square. Image plane position is -18,432
And so. (a), (b), and (c) are the object point coordinates (
0,0), (50nwn,, 50 nun), (5
0mm, -50mm). Spatial frequency 5c/
The MTF of mm is 94.2% in the X direction and 88% in the X direction in (a).
.. 0%, (b) 83.7% in the X direction, 84.4% in the X direction
, (c), it was 89.4% in the X direction and 90.6% in the X direction. It is said that the MFT required for a wall diagnostic camera is about 80%, so the above value satisfies this.
第3図には物体距離3fflのときのスポットダイヤグ
ラムを示す、このときの物点座標は(a)0,0、(b
H,5mn、1.5部wn、(c)1.5nn+−1,
5IInとなる。MTFは(a)でX方向93.8%、
X方向83.4%、(b)でX方向90゜9%、X方向
84.9%、(c)でX方向81.3%、y方向82゜
4%となった。中間距離例えば物体距離が丁度7mの位
置では、上記条件でMTFは99%以上となり、結局、
物体距離3m〜Loomの範囲においてほぼ満足な性能
が得られたことになる。また、第1図(b)では入射側
と出射側の光軸がたがいに平行にされているが、平行に
限られるねけではなく。Figure 3 shows a spot diagram when the object distance is 3ffl.The object point coordinates at this time are (a) 0,0, (b
H, 5mn, 1.5 parts wn, (c) 1.5nn+-1,
5IIn. MTF is 93.8% in the X direction in (a),
83.4% in the X direction, 90°9% in the X direction in (b) and 84.9% in the X direction, and 81.3% in the X direction and 82°4% in the y direction in (c). At an intermediate distance, for example, at a position where the object distance is exactly 7 m, the MTF will be over 99% under the above conditions, and eventually,
This means that almost satisfactory performance was obtained in the object distance range of 3 m to Loom. Furthermore, although the optical axes on the incident side and the output side are parallel to each other in FIG. 1(b), they are not limited to being parallel.
あまり大きな角度でなければMTFに殆ど影響がないこ
とが確かめられている。It has been confirmed that unless the angle is too large, there is almost no effect on MTF.
第4図はこの実施例の反射鏡配置を示す斜視図である。FIG. 4 is a perspective view showing the arrangement of reflecting mirrors in this embodiment.
図から見られるように大凹面鏡11と小凹面鏡12との
間が大きく開いており、ここを通って物体からの光束が
直接検知器に入ってしまう恐れがある。これに対しては
、同図(b)に示すように共有焦点14近傍に小さい開
口16を持った遮光板15をx−z平面に首けばよい。As can be seen from the figure, there is a large gap between the large concave mirror 11 and the small concave mirror 12, and there is a possibility that the light beam from the object may pass through this gap and directly enter the detector. To solve this problem, a light shielding plate 15 having a small aperture 16 near the common focal point 14 may be placed in the xz plane as shown in FIG. 2(b).
また、被走査点の距離の変化によって集束点の位置も変
化するが、第1図中の矢印Aのように検知器6を変位さ
せて対応することが出来る。Furthermore, the position of the focal point changes as the distance to the scanned point changes, but this can be accommodated by displacing the detector 6 as indicated by arrow A in FIG.
この実施例は反射鏡だけで構成され、透過レンズを全く
用いていないので、レンズ使用に伴う問題は一切生じな
い。Since this embodiment is composed only of reflecting mirrors and does not use any transmission lenses, there are no problems associated with the use of lenses.
(実施例2)
第5図は、両凹面鏡に回転放物面を用いた例である。回
転軸はZ軸となっているので、2軸に平行に入射する光
束は全て共有焦点14に集束し。(Example 2) FIG. 5 is an example in which a paraboloid of revolution is used as a biconcave mirror. Since the rotation axis is the Z axis, all the light beams incident parallel to the two axes are focused on the shared focal point 14.
この焦点から発散する光束は反射後は全てZ軸に平行な
光束となる。有限距離の物体からの光束は完全な平行光
束ではないが、はぼ平行に近いことは前の実施例の場合
と同じである。出射開口からのほぼ平行な光束は赤外線
透過性の材料、例えばゲルマニュウムのレンズ17に入
射し、レンズの後側焦点近傍に集束する。実際には被走
査点が無限遠距離にはないため、大凹面鏡からの出射光
束は緩い発散光束となり、小凹面鏡により反射された光
束は発散の度合がより強調されるので、レンズの後側焦
点よりは更に遠い点に集束する。物点距離の変化に対応
するためには検知器6かレンズ17を光軸方向に動かせ
ばよい。しかし、基準熱源7からの赤外光を検知器6に
入射させるためには集束点の位置は動かないほうが望ま
しい。そのためにはレンズ17によって合焦を行うのが
よい6大口面鏡の頂点の2座標をPい小凹面鏡のそれを
P2とすれば、それぞれの放物面は次式で表される。After being reflected, all of the light beams that diverge from this focal point become parallel to the Z-axis. Although the light beam from an object at a finite distance is not completely parallel, it is nearly parallel, as in the previous embodiment. A substantially parallel beam of light from the exit aperture enters a lens 17 made of an infrared transparent material, for example germanium, and is focused near the rear focal point of the lens. In reality, the point to be scanned is not at an infinite distance, so the light beam emitted from the large concave mirror becomes a loosely diverging light beam, and the light beam reflected by the small concave mirror has a more accentuated degree of divergence, so the back focus of the lens It focuses on a point even further away. In order to respond to changes in the object distance, the detector 6 or the lens 17 may be moved in the optical axis direction. However, in order to allow the infrared light from the reference heat source 7 to enter the detector 6, it is preferable that the position of the focal point does not move. For this purpose, it is preferable to focus using the lens 17.6If the two coordinates of the apex of the large aperture mirror are P and those of the small concave mirror are P2, each paraboloid is expressed by the following equation.
x”+y”=−4P1 (z−1’J) ・・・
(3)ただし
y≧O(i=1のとき)+y≦O(i=2のとき)第6
図は上式においてP、= −30mm、 P、= 7
。x"+y"=-4P1 (z-1'J)...
(3) However, y≧O (when i=1) + y≦O (when i=2) 6th
The figure shows P, = -30mm, P, = 7 in the above formula.
.
5m、入射開口40rm角としたときの光路を示し。The optical path is shown when the input aperture is 5 m and the incident aperture is 40 rm square.
出射開口はP2:Plによって決るので10mm角とな
る。レンズの開口もそれに・一致させて10mm角とし
、無限遠物体に対し球面収差を最少にするものとして、
第1面と第2面の曲率半径をそれぞれR1=40mm、
R,=80+amとしている。同図(b)(c)は物
体距離3m、像面距1iz=−59,97、物点座標(
0,0)および(1,5mm、1.5mm)の場合のス
ポットダイヤグラムを示す。このときのMTFは(b)
でX方向91.4%、y方向93.1%、(c)でX方
向91゜4%、y方向92.3%であった。同じ光学系
で物点距離を50+n、像面をz=−56,82とした
場合のMTFは何れも94.3%以上となる。Since the exit aperture is determined by P2:Pl, it is 10 mm square. The aperture of the lens is also 10 mm square to match this, and the spherical aberration for objects at infinity is minimized.
The radius of curvature of the first and second surfaces is R1 = 40 mm, respectively.
R,=80+am. In the same figure (b) and (c), the object distance is 3 m, the image plane distance 1iz = -59,97, and the object point coordinates (
0,0) and (1,5 mm, 1.5 mm) are shown. The MTF at this time is (b)
In (c), it was 91.4% in the X direction and 93.1% in the y direction, and in (c), it was 91.4% in the X direction and 92.3% in the y direction. In the same optical system, when the object point distance is 50+n and the image plane is z=-56, 82, the MTF is 94.3% or more.
(実施例3)
第7図は大凹面鏡11として回転楕円面鏡、小凹面鏡1
2として回転放物面鏡を用いた例である。(Example 3) FIG. 7 shows a spheroidal mirror as a large concave mirror 11 and a small concave mirror 1 as a small concave mirror 1.
2 is an example in which a parabolic mirror of revolution is used.
大凹面鏡11の形状は(1)、(2)式で表され、小凹
面鏡12の形状は(3)式で表される。大凹面鏡11の
物体側焦点位置をz=2c=6m、頂点座標z=a−c
=20mmとしたときの物体距離Loomに対するスポ
ットダイヤグラムを第8図ニ示ス。物体am ハ(a
) 0,0、(b ) 50mm、50mm。The shape of the large concave mirror 11 is expressed by equations (1) and (2), and the shape of the small concave mirror 12 is expressed by equation (3). The object-side focal point of the large concave mirror 11 is z=2c=6m, and the vertex coordinates are z=a-c.
Figure 8 shows a spot diagram for the object distance Loom when = 20 mm. Object am ha (a
) 0,0, (b) 50mm, 50mm.
像面はz=−45,126とした。このときのMTFは
(a)でX方向93.8%、y方向95.0%、(b)
でX方向91.1%、y方向95.5%であった。同じ
光学系でより近い物体きよりにたいするMTFは何れも
これより高く、最高96.8%であった。The image plane was set at z=-45,126. The MTF at this time is (a) 93.8% in the X direction and 95.0% in the y direction, (b)
It was 91.1% in the X direction and 95.5% in the Y direction. The MTF for closer objects using the same optical system was higher than this, with a maximum of 96.8%.
(実施例4)
上記実施例では大凹面鏡11の物体側焦点位置を2軸上
に置いたので、反射鏡系の光軸はZ軸と平行にならなか
ったが、第9図に示すように物体側焦点位置のy座標を
入射開口の中心と同じにすれば、光軸はZ軸と平行にな
る。前の実施例と同じに入射開口を40mm角とし、物
体側焦点位置を6mとすれば、楕円の長径のZ軸に対す
る傾きは約11.5’ となる。この構成は両凹面鏡の
光軸が平行になるので設計が容易になり、性能的には実
施例3と殆ど差がなく、MTFは95.2〜97.3%
の間であった。(Example 4) In the above example, since the object side focal point position of the large concave mirror 11 was placed on two axes, the optical axis of the reflecting mirror system was not parallel to the Z axis, but as shown in FIG. If the y-coordinate of the object-side focal position is made the same as the center of the entrance aperture, the optical axis becomes parallel to the Z-axis. Assuming that the entrance aperture is 40 mm square and the object side focal position is 6 m as in the previous embodiment, the inclination of the major axis of the ellipse with respect to the Z axis is approximately 11.5'. In this configuration, the optical axes of the biconcave mirrors are parallel, making the design easier, and there is almost no difference in performance from Example 3, with an MTF of 95.2 to 97.3%.
It was between.
(実施例5)
第10図は実施例1と同様両凹面鏡を回転楕円面とし、
これにレンズ17を導入したものである。(Example 5) Figure 10 shows a biconcave mirror with a spheroidal surface as in Example 1,
A lens 17 is added to this.
この場合の性能も実施例3とほぼ同様で、MTFは92
62〜96,1%の間であった。The performance in this case is also almost the same as in Example 3, and the MTF is 92.
It was between 62 and 96.1%.
これらの実施例においても実施例1と同様の遮光板を挿
入するのがよく、また、レンズもその形状は勿論、2枚
、3枚を用いた複合レンズでもよい等、各種の設計変更
が可能なことは言うまでもない。In these embodiments as well, it is preferable to insert a light-shielding plate similar to that in embodiment 1, and various design changes are possible, such as the shape of the lens as well as a compound lens using two or three lenses. Needless to say.
(実施例6)
第2の小反射鏡を凸面鏡とし、所謂カセグレンタイプの
構成とすることも出来る。第11図にその1例を示す。(Embodiment 6) It is also possible to use a convex mirror as the second small reflecting mirror to have a so-called Cassegrain type structure. An example is shown in FIG.
大凹面鏡11と小凸面鏡12′は共に回転放物面であり
、共軸、共焦点に配置され。Both the large concave mirror 11 and the small convex mirror 12' are paraboloids of revolution, and are arranged coaxially and confocally.
小反射鏡からの反射光は大凹面鏡の中心に設けられた開
口部を通して出射し、検知器6上に集束する。The reflected light from the small reflecting mirror exits through an opening provided at the center of the large concave mirror and is focused on the detector 6.
放物面を表す式(3)において、大凹面鏡11でP1=
10mm、小凸面鏡12′でP、=2.5mmの場合、
開口を直径40mmとすれば、凸面鏡による光束のケラ
レは約1/16 (約6%)となる、Geレンズは入射
側半径R1=25mm、出射側半径R2=36nwn、
厚さ3mmの凸メニスカスレンズとしたとき、物点が5
0Inとして集束点位iz中−33,7mm、最小錯乱
円径約16μmとなる。In equation (3) representing a paraboloid, P1=
10mm, and when P = 2.5mm with a small convex mirror 12',
If the diameter of the aperture is 40 mm, the vignetting of the light beam due to the convex mirror will be approximately 1/16 (approximately 6%). The Ge lens has an input side radius R1 = 25 mm, an output side radius R2 = 36nwn,
When using a convex meniscus lens with a thickness of 3 mm, the object point is 5.
Assuming 0In, the focal point position iz is -33.7 mm, and the diameter of the circle of minimum confusion is approximately 16 μm.
第12図の場合はp、= 15mm、 p、= 2 、
5mm、開口は直径40mmとし、凸面鏡の有効径もそ
れに比例させて小としたものであるにの場合の最小錯乱
円径は約4.9μmとなる。In the case of Fig. 12, p, = 15 mm, p, = 2,
5 mm, the diameter of the aperture is 40 mm, and the effective diameter of the convex mirror is made proportionally smaller.The diameter of the circle of least confusion is approximately 4.9 μm.
なお、回転双曲面鏡を用いた場合、−焦点に集束する光
束は反射接地の焦点に無収差で集束する性質を利用して
、この種の反射光学系において小凸面鏡として用いられ
ることは周知であり、この実施例においても利用可能で
ある。It is well known that when a rotating hyperboloid mirror is used, it can be used as a small convex mirror in this type of reflective optical system by taking advantage of the property that the light beam converged to the focal point is converged to the reflective ground focal point without aberration. Yes, and can be used in this embodiment as well.
(実施例7)
第13図に小凸面鏡を用いた反射光学系を有する赤外線
カメラの全体構成の1例を示す。この光学系では、光軸
を含む光軸近傍の空間は被写体からの有効光束は通らな
いので、レンズ後方のこの空間内に支持棒18で支持さ
れた反射鏡19を設け、基準熱源7からの赤外線を集束
光として入射させることで検知器6に基準熱源像を結ば
せることが出来る。(Embodiment 7) FIG. 13 shows an example of the overall configuration of an infrared camera having a reflective optical system using a small convex mirror. In this optical system, since the effective light flux from the subject does not pass through the space near the optical axis including the optical axis, a reflecting mirror 19 supported by a support rod 18 is provided in this space behind the lens, and the space near the optical axis includes the optical axis. A reference heat source image can be formed on the detector 6 by injecting infrared rays as focused light.
発明の効果
この発明は上記のように被写体からの赤外線を反射鏡光
学系によって集束結像させ実用上充分な性能を持たせる
ことが出来たもので、Geレンズの使用に伴う問題は生
ぜず、低コストの赤外線カメラを得ることが出来る。Effects of the Invention As described above, this invention was able to focus and image the infrared rays from the object using a reflecting mirror optical system, and to have sufficient performance for practical use, and the problems associated with the use of Ge lenses did not occur. A low-cost infrared camera can be obtained.
また1例えば第10図の光学系はFナンバーがほぼ2に
なっており、通常レンズだけで構成されているものはF
lであるのに比して暗過ぎる心配があるが、レンズの焦
点距離を短くして明るさを増すことが出来る。このとき
、レンズの構成枚数を増やすことによってMTFを維持
出来る。1. For example, the optical system shown in Figure 10 has an F number of approximately 2, and an optical system that consists of only a normal lens has an F number of approximately 2.
Although there is a concern that it will be too dark compared to the 1-inch lens, the brightness can be increased by shortening the focal length of the lens. At this time, MTF can be maintained by increasing the number of lenses.
さらにこの種の赤外線カメラは被写体距離が3〜100
mという非常に広い範囲で使用されるため、合焦操作が
必要となる。この目的で検知器を移動させるのは、多く
の場合検知器は冷却装置と一体になっているため困難で
ある。小反射鏡を移動させるのは、両反射鏡を共焦点で
配置するという条件を崩し、性能を維持出来なくなる。Furthermore, this type of infrared camera has a subject distance of 3 to 100
Since it is used over a very wide range of m, a focusing operation is required. Moving the detector for this purpose is difficult as the detector is often integrated with the cooling system. Moving the small reflector breaks the condition of arranging both reflectors in a confocal position, making it impossible to maintain performance.
このためGeレンズを導入し、合焦用とするのが有利で
ある。For this reason, it is advantageous to introduce a Ge lens and use it for focusing.
上記のようにMTFの向上、明るさの増加および合焦の
ためGeレンズを用いることが有利であるが、小反射鏡
の出射開口は大反射鏡の入射開口に比して両反射鏡の相
似比の割で小となり、上記の実施例では、出射開口40
mm角に対して出射開口は10rnffi角となってお
り、レンズの大きさも1/4以下、従ってその材料の使
用料は1764にも低下し、大幅なコスト低下が可能で
ある。As mentioned above, it is advantageous to use a Ge lens to improve MTF, increase brightness, and focus, but the exit aperture of the small reflector is similar to that of both reflectors compared to the input aperture of the large reflector. In the above embodiment, the output aperture 40
The exit aperture is 10 rnffi angle compared to the mm angle, and the size of the lens is less than 1/4, so the cost of the material used can be reduced to 1764 mm, making it possible to significantly reduce costs.
第1図はこの発明の赤外線カメラ用反射光学系の1実施
例の構成を示す断面図、第2図、第3図はそのスポット
ダイヤグラム、第4図はその反射鏡配巴を示す斜視図お
よび断面図、第5図、第6図は実施例2の構成を示す断
面図およびそのスポットダイヤグラム、第7図、第8図
は実施例3の構成を示す断面図およびそのスポットダイ
ヤグラム、第9図、第10図は実施例4および実施例5
の構成を示す断面図、第11図、第12図は実施例6の
構成を示す光路図、第13図は実施例6を用いた赤外線
カメラの構成図、第14図は公知の赤外線カメラの構成
図である。
1:赤外線カメラ 2:赤外線入射窓3:走査鏡
4:集光レンズ5:リレーレンズ 6:
検知器
7:基準熱源 8:レンズ
9:チョッパ反射鏡 11:大口面鏡12:小凹面鏡
12′ :小凸面鏡13:被走査点 1
4:共有焦点15:遮光板 16:開口部
17:レンズ 18:支持棒
19:反射鏡
特許出願人 株式会社 リ コ −
出願人代理人 弁理士 佐藤文男
(他2名)
$2図
(b)
駆 3 図
(b)
第4図
yL 6 図
(−0,1、−Q、l )
(b) (c)簗
7 図
≠ 8 図
4(9図
51t10 図FIG. 1 is a sectional view showing the configuration of one embodiment of the reflective optical system for an infrared camera according to the present invention, FIGS. 2 and 3 are spot diagrams thereof, and FIG. 4 is a perspective view showing the arrangement of the reflective mirrors. 5 and 6 are cross-sectional views showing the configuration of Example 2 and their spot diagrams; FIGS. 7 and 8 are cross-sectional views showing the configuration of Example 3 and their spot diagrams; FIG. 9; , FIG. 10 shows Example 4 and Example 5.
11 and 12 are optical path diagrams showing the configuration of Example 6, FIG. 13 is a configuration diagram of an infrared camera using Example 6, and FIG. 14 is a diagram of a known infrared camera. FIG. 1: Infrared camera 2: Infrared entrance window 3: Scanning mirror
4: Condensing lens 5: Relay lens 6:
Detector 7: Reference heat source 8: Lens 9: Chopper reflector 11: Large mirror 12: Small concave mirror 12': Small convex mirror 13: Scanned point 1
4: Shared focus 15: Light shielding plate 16: Opening 17: Lens 18: Support rod 19: Reflector Patent applicant Rico Co., Ltd. - Applicant's agent Patent attorney Fumio Sato (2 others) $2 Figure (b) Kaku 3 Figure (b) Figure 4 yL 6 Figure (-0, 1, -Q, l) (b) (c) Glans
7 Figure ≠ 8 Figure 4 (9 Figure 51t10 Figure
Claims (1)
、入射開口部を上記平面ミラーに向けた回転2次曲面か
らなる第1凹面鏡とこれに対向する回転2次曲面からな
る第2の小鏡を含み、これらの両反射鏡はその焦点を共
有し、第2の小鏡からの出射赤外線の集束点近傍に検知
器を配置することを特徴とする赤外線カメラ 2)平面ミラー対物面走査方式の赤外線カメラにおいて
、入射開口部を上記平面ミラーに向けた回転2次曲面か
らなる第1凹面鏡とこれに対向する回転2次曲面からな
る第2の凹面小鏡を含み、これらの両反射鏡はその焦点
を共有すると共に上記共有焦点を通る一平面に関し互い
に逆側に配置され、上記小鏡からの出射赤外線の集束点
近傍に検知器を配置することを特徴とする赤外線カメラ
3)平面ミラー対物面走査方式の赤外線カメラにおいて
、入射開口部を上記平面ミラーに向け中心部に光通過用
の孔を設けた回転2次曲面からなる第1凹面鏡と、これ
に対向し上記光通過用の孔とほぼ同じ大きさの回転2次
曲面からなる第2の凸面小鏡を含み、これらの両反射鏡
はその焦点を共有し、第2の小鏡からの出射赤外線の集
束点近傍に検知器を配置することを特徴とする赤外線カ
メラ 4)平面ミラー対物面走査方式の赤外線カメラにおいて
、入射開口部を上記平面ミラーに向けた回転2次曲面か
らなる第1凹面鏡とこれに対向する回転2次曲面からな
る第2の小鏡を含み、これらの両反射鏡はその焦点を共
有し、第2の小鏡からの出射赤外線は赤外線透過材料に
よって作られたレンズを介して集束され、該集束点近傍
に検知器を配置することを特徴とする赤外線カメラ[Scope of Claims] 1) In an infrared camera of a plane mirror object plane scanning type, a first concave mirror is formed of a rotating quadratic curved surface with an entrance aperture facing the plane mirror, and a second concave mirror is formed of a rotating quadratic curved surface opposite to the first concave mirror. An infrared camera comprising two small mirrors, both of which share a focal point, and a detector is disposed near the focal point of the infrared light emitted from the second small mirror.2) Flat mirror objective. A surface scanning type infrared camera includes a first concave mirror made of a rotational quadratic curved surface with an incident aperture facing the plane mirror, and a second concave small mirror made of a rotational quadratic curved surface opposing the first concave mirror, and both of these mirrors are provided. An infrared camera 3) characterized in that the reflecting mirrors share a focal point and are arranged on opposite sides of each other with respect to a plane passing through the shared focal point, and a detector is arranged near the focal point of the infrared rays emitted from the small mirror. In an infrared camera of a plane mirror object plane scanning type, a first concave mirror is formed of a rotating quadratic curved surface with an entrance aperture facing the plane mirror and a hole for passing light in the center, and a first concave mirror opposite to this and having a hole for passing light. It includes a second convex small mirror consisting of a rotating quadratic curved surface with approximately the same size as the hole, and both of these reflecting mirrors share their focal point, and the infrared rays emitted from the second small mirror are detected near the convergence point. 4) In an infrared camera of a plane mirror object plane scanning type, a first concave mirror consisting of a rotating quadratic curved surface with an entrance aperture facing the plane mirror, and a rotating second concave mirror opposite thereto; It includes a second small mirror with a curved surface, both of these reflecting mirrors share their focal point, and the outgoing infrared rays from the second small mirror are focused through a lens made of an infrared transparent material, and the focused An infrared camera characterized by placing a detector near a point
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP61005054A JPS62164010A (en) | 1986-01-16 | 1986-01-16 | Infrared ray camera |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP61005054A JPS62164010A (en) | 1986-01-16 | 1986-01-16 | Infrared ray camera |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS62164010A true JPS62164010A (en) | 1987-07-20 |
Family
ID=11600683
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP61005054A Pending JPS62164010A (en) | 1986-01-16 | 1986-01-16 | Infrared ray camera |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS62164010A (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0572477A (en) * | 1991-09-13 | 1993-03-26 | Toshiba Corp | Afocal optical device |
JPH075363A (en) * | 1993-06-16 | 1995-01-10 | Tech Res & Dev Inst Of Japan Def Agency | Non-axial and confocal multi-surface reflection optical system |
JP2000022220A (en) * | 1998-07-03 | 2000-01-21 | Stanley Electric Co Ltd | Reflective led lamp |
WO2000048033A1 (en) * | 1999-02-10 | 2000-08-17 | Matsushita Electric Industrial Co., Ltd. | Reflection optical device, reflection solid-state optical device, imaging device comprising this, multiwavelength imaging device, video camera, and monitoring device mounted on vehicle |
WO2001092956A1 (en) * | 2000-05-30 | 2001-12-06 | Mitsubishi Denki Kabushiki Kaisha | Image sensor |
US6929373B2 (en) | 2001-04-11 | 2005-08-16 | Matsushita Electric Industrial Co., Ltd. | Reflection optical device and imaging apparatus comprising it, multi-wavelength imaging apparatus, and vehicle mounted monitor |
CN102323710A (en) * | 2011-09-20 | 2012-01-18 | 苏州梦想人软件科技有限公司 | Camera imaging auxiliary apparatus and image imaging processing method |
CN105607251A (en) * | 2015-12-31 | 2016-05-25 | 南京华图信息技术有限公司 | Multi-mode infrared imaging system and method facing weak target detection |
CN108732734A (en) * | 2018-05-30 | 2018-11-02 | 南京信息工程大学 | The reflective LONG WAVE INFRARED finder optical system of fast coke ratio based on free form surface |
-
1986
- 1986-01-16 JP JP61005054A patent/JPS62164010A/en active Pending
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0572477A (en) * | 1991-09-13 | 1993-03-26 | Toshiba Corp | Afocal optical device |
JPH075363A (en) * | 1993-06-16 | 1995-01-10 | Tech Res & Dev Inst Of Japan Def Agency | Non-axial and confocal multi-surface reflection optical system |
JP2000022220A (en) * | 1998-07-03 | 2000-01-21 | Stanley Electric Co Ltd | Reflective led lamp |
US6908200B1 (en) | 1999-02-10 | 2005-06-21 | Matsushita Electric Industrial Co., Ltd. | Reflection optical device, and reflection solid-state optical device, imaging device comprising this, multiwavelength imaging device, video camera, and monitoring device mounted on vehicle |
US6896382B2 (en) | 1999-02-10 | 2005-05-24 | Matsushita Electric Industrial Co., Ltd. | Reflective optical device, and reflective solid-state optical device, and imaging device, multi-wavelength imaging device, video camera device, and vehicle-mounted monitor utilizing the same |
WO2000048033A1 (en) * | 1999-02-10 | 2000-08-17 | Matsushita Electric Industrial Co., Ltd. | Reflection optical device, reflection solid-state optical device, imaging device comprising this, multiwavelength imaging device, video camera, and monitoring device mounted on vehicle |
JP2008052287A (en) * | 1999-02-10 | 2008-03-06 | Matsushita Electric Ind Co Ltd | Reflection optical device, reflection solid-state optical device imaging device comprising this, multiwavelength imaging device, video camera, and monitoring device mounted on vehicle |
WO2001092956A1 (en) * | 2000-05-30 | 2001-12-06 | Mitsubishi Denki Kabushiki Kaisha | Image sensor |
US6985268B1 (en) | 2000-05-30 | 2006-01-10 | Mitsubishi Denki Kabushiki Kaisha | Image capturing apparatus |
US6929373B2 (en) | 2001-04-11 | 2005-08-16 | Matsushita Electric Industrial Co., Ltd. | Reflection optical device and imaging apparatus comprising it, multi-wavelength imaging apparatus, and vehicle mounted monitor |
CN102323710A (en) * | 2011-09-20 | 2012-01-18 | 苏州梦想人软件科技有限公司 | Camera imaging auxiliary apparatus and image imaging processing method |
CN105607251A (en) * | 2015-12-31 | 2016-05-25 | 南京华图信息技术有限公司 | Multi-mode infrared imaging system and method facing weak target detection |
CN105607251B (en) * | 2015-12-31 | 2017-03-22 | 南京华图信息技术有限公司 | Multi-mode infrared imaging system and method facing weak target detection |
CN108732734A (en) * | 2018-05-30 | 2018-11-02 | 南京信息工程大学 | The reflective LONG WAVE INFRARED finder optical system of fast coke ratio based on free form surface |
CN108732734B (en) * | 2018-05-30 | 2020-12-25 | 南京信息工程大学 | Free-form surface-based fast-focus ratio reflection type long-wave infrared viewfinder optical system |
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