JPH0666631A - Infrared image sensor - Google Patents
Infrared image sensorInfo
- Publication number
- JPH0666631A JPH0666631A JP4219048A JP21904892A JPH0666631A JP H0666631 A JPH0666631 A JP H0666631A JP 4219048 A JP4219048 A JP 4219048A JP 21904892 A JP21904892 A JP 21904892A JP H0666631 A JPH0666631 A JP H0666631A
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- Prior art keywords
- filter
- lens system
- solid
- equation
- image
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- 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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- Optical Filters (AREA)
- Transforming Light Signals Into Electric Signals (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】この発明は、固体撮像素子によっ
て撮像する赤外線撮像装置の構成に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an infrared image pickup device for picking up an image by a solid-state image pickup device.
【0002】[0002]
【従来の技術】図5は従来の赤外線撮像装置の構成例で
あり、図において、1はレンズ系、2は上記レンズ系1
によって集光された光線を透過するフィルタ、3は上記
レンズ系1によって集光された上記フィルタ2を透過し
た光線を受光する固体撮像素子、4は上記固体撮像素子
3から出力された電気信号を増幅する増幅器、5は上記
増幅器4によって増幅された電気信号を記憶する記憶装
置、6は上記増幅器4から出力される電気信号と上記記
憶装置5によって記憶された電気信号を演算処理する処
理装置、7は上記処理装置6によって処理された電気信
号を画像として表示する表示装置、8は上記固体撮像素
子3の前面に位置するシャッタである。2. Description of the Related Art FIG. 5 shows an example of the configuration of a conventional infrared imaging device. In the figure, 1 is a lens system and 2 is the lens system 1.
Is a solid-state image sensor that receives the light rays that are transmitted by the lens system 1 and that is transmitted through the filter 2, and 4 is an electric signal that is output from the solid-state image sensor 3. An amplifier 5 for amplification, a storage device for storing the electric signal amplified by the amplifier 4, a processing device 6 for processing the electric signal output from the amplifier 4 and the electric signal stored by the storage device 5, Reference numeral 7 is a display device for displaying an electric signal processed by the processing device 6 as an image, and 8 is a shutter located on the front surface of the solid-state imaging device 3.
【0003】従来の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。レンズ系1によって集光
されフィルタ2を透過した光線は、固体撮像素子3で受
光され、その画像を電気信号として外部に出力する。出
力された電気信号は増幅器4によって増幅された後、表
示装置7によって画像として表示される。固体撮像素子
3は、均一な光線を入射させても出力値は画素ごとにば
らつきを持っている。そのため、このばらつきを補正す
る感度補正が以下のように行われる。まず、固体撮像素
子3の前面に設置したシャッタ8を閉じて固体撮像素子
3に均一な光線を入射させ、その時の画素ごとの出力信
号を記憶装置5にあらかじめ記憶させておく。次に、目
標物を撮像する際に、シャッタ8を開いて目標物からの
光線を固体撮像素子3で受光し電気信号を出力する。処
理装置6においてこの出力された電気信号から記憶装置
5にあらかじめ記憶させておいた電気信号を減算して感
度補正を行い、表示装置7に画像として表示する。The conventional infrared imaging device is constructed as described above and operates as follows. The light beam condensed by the lens system 1 and transmitted through the filter 2 is received by the solid-state image sensor 3, and the image is output to the outside as an electric signal. The output electric signal is amplified by the amplifier 4 and then displayed as an image by the display device 7. The output value of the solid-state image sensor 3 varies from pixel to pixel even when a uniform light beam is incident. Therefore, sensitivity correction for correcting this variation is performed as follows. First, the shutter 8 installed on the front surface of the solid-state image sensor 3 is closed to cause a uniform light beam to enter the solid-state image sensor 3, and the output signal for each pixel at that time is stored in the storage device 5 in advance. Next, when the target object is imaged, the shutter 8 is opened and the light beam from the target object is received by the solid-state image sensor 3 and an electric signal is output. In the processing device 6, the electric signal stored in the storage device 5 in advance is subtracted from the output electric signal to perform sensitivity correction, and the image is displayed on the display device 7 as an image.
【0004】[0004]
【発明が解決しようとする課題】上記のような従来の赤
外線撮像装置においては、感度補正を行う際にシャッタ
8を用いて均一な光線を得ているが、この光線は撮像目
標輝度と異なっており、さらに、シャッタ8は赤外線撮
像装置の使用中に温度が上昇するのでますますこの光線
は撮像目標輝度と異なってしまう。そのため、感度補正
が十分に行われず、表示装置7によって表示される画像
にノイズが生じるという問題点があった。In the conventional infrared image pickup device as described above, a uniform light beam is obtained by using the shutter 8 when sensitivity correction is performed, but this light beam is different from the image pickup target luminance. In addition, the temperature of the shutter 8 rises during use of the infrared image pickup device, so that this light ray becomes different from the image pickup target brightness. Therefore, the sensitivity is not sufficiently corrected, and there is a problem that noise is generated in the image displayed by the display device 7.
【0005】この発明は上記のような問題点を解決する
ためになされたものであり、固体撮像素子の各画素が撮
像目標から受光し蓄積する受光量を各画素で等しくし、
その際の各画素の出力値を記憶装置に記憶して感度補正
を行うことにより、適正な感度補正を行い、ノイズの少
ない画像を得ることを目的とする。The present invention has been made in order to solve the above-mentioned problems, and equalizes the amount of light received by each pixel of the solid-state image pickup device from the image pickup target and accumulated in each pixel,
It is an object of the present invention to obtain an image with less noise by performing appropriate sensitivity correction by storing the output value of each pixel at that time in a storage device and performing sensitivity correction.
【0006】[0006]
【課題を解決するための手段】この発明に係る赤外線撮
像装置は、レンズ系と固体撮像素子の間に位置するフィ
ルタを厚みの異なるフィルタに交換するものである。In the infrared image pickup device according to the present invention, the filter located between the lens system and the solid-state image pickup device is replaced with a filter having a different thickness.
【0007】もう1つの発明に係る赤外線撮像装置は、
光学系と固体撮像素子の間に位置するフィルタを屈折率
の異なるフィルタに交換するものである。An infrared imaging device according to another invention is
The filter located between the optical system and the solid-state image sensor is replaced with a filter having a different refractive index.
【0008】[0008]
【作用】この発明における赤外線撮像装置は、厚みの異
なるフィルタに交換することにより撮像目標から固体撮
像素子が蓄積する受光量を各画素で等しくし、その出力
信号を基に感度補正が行われるので出力画像のノイズが
減少する。In the infrared image pickup device according to the present invention, the amount of light received by the solid-state image pickup element from the image pickup target is made equal for each pixel by exchanging with a filter having a different thickness, and sensitivity correction is performed based on the output signal. Output image noise is reduced.
【0009】もう1つの発明における赤外線撮像装置
は、屈折率の異なるフィルタに交換することにより撮像
目標から固体撮像素子が蓄積する受光量を各画素で等し
くし、その出力信号を基に感度補正が行われるので出力
画像のノイズが減少する。In the infrared image pickup device according to another aspect of the present invention, the amount of light received by the solid-state image pickup device from the image pickup target is made equal in each pixel by replacing with a filter having a different refractive index, and sensitivity correction is performed based on the output signal. Since this is done, the noise in the output image is reduced.
【0010】[0010]
実施例1.以下、この発明の一実施例を図について説明
する。図1において、1及び3〜7は従来例と同一の名
称と機能を有する部分、9は上記光学系1が集光した光
線の光路上に位置する第1のフィルタ(以下フィルタα
という)、10はフィルタ交換機構によって上記フィル
タα9と交換出来る第2のフィルタ(以下フィルタβと
いう)である。Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 and 3 to 7 are portions having the same names and functions as those of the conventional example, and 9 is a first filter (hereinafter referred to as a filter α) located on the optical path of the light beam condensed by the optical system 1.
10 is a second filter (hereinafter referred to as filter β) that can be replaced with the filter α9 by a filter replacement mechanism.
【0011】この発明におけ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。感度補正を行
う際には、レンズ系1の視野内に撮像目標を入れた状態
でフィルタβ10をレンズ系1と固体撮像素子3の間に
挿入する。上記状態で撮像目標からの光線を固体撮像素
子3で受光して各画素ごとの出力値を記憶装置5に記憶
する。次に、フィルタα9をフィルタβ10と交換して
レンズ系1と固体撮像素子3の間に挿入する。この状態
で撮像目標からの光線を固体撮像素子3で受光し電気信
号を出力する。処理装置6においてこの出力された電気
信号から記憶装置5にあらかじめ記憶させておいた電気
信号を減算して感度補正を行い、表示装置7に画像とし
て表示する。The infrared imaging device according to the present invention is constructed as described above and operates as follows. When performing the sensitivity correction, the filter β10 is inserted between the lens system 1 and the solid-state imaging device 3 with the imaging target placed within the field of view of the lens system 1. In the above state, the solid-state image sensor 3 receives the light beam from the imaging target and stores the output value of each pixel in the storage device 5. Next, the filter α9 is replaced with the filter β10, and the filter α9 is inserted between the lens system 1 and the solid-state imaging device 3. In this state, the light beam from the imaging target is received by the solid-state imaging device 3 and an electric signal is output. In the processing device 6, the electric signal stored in the storage device 5 in advance is subtracted from the output electric signal to perform sensitivity correction, and the image is displayed on the display device 7 as an image.
【0012】フィルタα9をレンズ系1と固体撮像素子
3の間に挿入した状態で撮像目標を撮像すると撮像目標
からの光線は図1のように固体撮像素子3の受光面上に
結像するが、フィルタβ10をレンズ系1と固体撮像素
子3の間に挿入した状態で撮像目標を撮像すると撮像目
標からの光線は図2のように固体撮像素子3の受光面上
で結像しない。フィルタα9の厚さをdαフィルタβ1
0の厚さをdβ、フィルタα9とフィルタβ10の屈折
率をn、固体撮像素子3の受光面に対し垂直な平行光線
がレンズ系1に入射した際、フィルタα及びフィルタβ
への光線の最大入射角をiとした時、フィルタα9とフ
ィルタβ10をそれぞれ使用した時の結像位置の差は、
(7)式呼び(8)式から求まる値の差の絶対値|ζα
−ζβ|である。When the image pickup target is imaged with the filter α9 inserted between the lens system 1 and the solid-state image pickup device 3, the light beam from the image pickup target forms an image on the light receiving surface of the solid-state image pickup device 3 as shown in FIG. When the image pickup target is picked up with the filter β10 inserted between the lens system 1 and the solid state image pickup device 3, the light rays from the image pickup target are not formed on the light receiving surface of the solid state image pickup device 3 as shown in FIG. The thickness of the filter α9 is set to dα filter β1
When the thickness of 0 is dβ, the refractive indices of the filters α9 and β10 are n, and parallel rays perpendicular to the light receiving surface of the solid-state imaging device 3 are incident on the lens system 1, the filters α and β
When the maximum angle of incidence of the light ray on is i, the difference between the imaging positions when the filter α9 and the filter β10 are used is
Absolute value of the difference between the values obtained from equation (7) and equation (8) |
−ζβ |.
【0013】[0013]
【数7】 [Equation 7]
【0014】[0014]
【数8】 [Equation 8]
【0015】光学系の焦点深度をεとした時、(9)式
を満足していれば、フィルタβ10を使用した状態で撮
像目標を光学系の視野内に入れ受光光線を蓄積すると、
像がぼけることにより像の持つ光強度分布が均一化さ
れ、固体撮像素子3の各画素が蓄積する受光量はそれぞ
れ等しくなる。Assuming that the depth of focus of the optical system is ε, if the expression (9) is satisfied, if the image pickup target is put in the visual field of the optical system while the filter β10 is used, and the received light beam is accumulated,
By blurring the image, the light intensity distribution of the image is made uniform, and the amount of received light accumulated in each pixel of the solid-state image sensor 3 becomes equal.
【0016】[0016]
【数9】 [Equation 9]
【0017】記憶装置5に記憶した各画素ごとの出力値
は撮像目標からの光線を各画素が等しく一定量受光した
値なので、フィルタα9を使用して撮像する際にその記
憶した出力信号を基に感度補正を行うノイズが少ない出
力画像を表示装置7に表示できる。フィルタα9及びフ
ィルタβ10が(9)式を満足していない場合、感度補
正を行うと、記憶装置5に記憶する固体撮像素子3の各
画素ごとの出力値は像の持つ不均一な光強度分布を記憶
することになる。その出力値を基に感度補正を行うと、
出力画像に記憶装置5に記憶した不均一な光強度分布が
残像として生じてしまい、かえって出力画像が劣化して
しまう。そのために、(9)式の関係を満足するような
フィルタβ10を用意する必要がある。感度補正が上記
の方法で行われる以外は従来の赤外線撮像装置と同様に
動作する。Since the output value for each pixel stored in the storage device 5 is a value in which each pixel equally receives a light beam from the image pickup target by a fixed amount, when the image is picked up using the filter α9, the stored output signal is used as a basis. An output image with less noise for which sensitivity correction is performed can be displayed on the display device 7. When the filter α9 and the filter β10 do not satisfy the expression (9), when the sensitivity correction is performed, the output value for each pixel of the solid-state image sensor 3 stored in the storage device 5 has an uneven light intensity distribution of the image. Will be remembered. When sensitivity correction is performed based on the output value,
The non-uniform light intensity distribution stored in the storage device 5 is generated as an afterimage in the output image, which rather deteriorates the output image. Therefore, it is necessary to prepare the filter β10 that satisfies the relationship of the expression (9). The operation is similar to that of the conventional infrared imaging device except that the sensitivity correction is performed by the above method.
【0018】実施例2.次にこの発明の他の実施例を図
について説明する。図3において、1及び3〜7は従来
例と同一の名称と機能を有する部分、11は上記光学系
1が集光した光線の光路上に位置する第1のフィルタ
(以下フィルタγという)、12はフィルタ交換機構に
よって上記フィルタγ11と交換出来る第2のフィルタ
(以下フィルタδという)である。Example 2. Next, another embodiment of the present invention will be described with reference to the drawings. In FIG. 3, 1 and 3 to 7 are portions having the same names and functions as those of the conventional example, 11 is a first filter (hereinafter referred to as a filter γ) located on the optical path of the light beam condensed by the optical system 1. Reference numeral 12 is a second filter (hereinafter referred to as filter δ) that can be replaced with the filter γ11 by a filter replacement mechanism.
【0019】図3に示す実施例の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。感度補正を
行う際には、レンズ系1の視野内に撮像目標を入れた状
態でフィルタδ12をレンズ系1と固体撮像素子3の間
に挿入する。上記状態で撮像目標からの光線を固体撮像
素子3で受光して各画素ごとの出力値を記憶装置5に記
憶する。次に、フィルタγ11をフィルタδ12と交換
してレンズ系1と固体撮像素子3の間に挿入する。この
状態で撮像目標からの光線を固体撮像素子3で受光し電
気信号を出力する。処理装置6においてこの出力された
電気信号から記憶装置5にあらかじめ記憶させておいた
電気信号を減算して感度補正を行い、表示装置7に画像
として表示する。The infrared imaging apparatus of the embodiment shown in FIG. 3 is constructed as described above and operates as follows. When performing the sensitivity correction, the filter δ12 is inserted between the lens system 1 and the solid-state image sensor 3 with the imaging target in the field of view of the lens system 1. In the above state, the solid-state image sensor 3 receives the light beam from the imaging target and stores the output value of each pixel in the storage device 5. Next, the filter γ11 is replaced with the filter δ12 and is inserted between the lens system 1 and the solid-state image sensor 3. In this state, the light beam from the imaging target is received by the solid-state imaging device 3 and an electric signal is output. In the processing device 6, the electric signal stored in the storage device 5 in advance is subtracted from the output electric signal to perform sensitivity correction, and the image is displayed on the display device 7 as an image.
【0020】フィルタγ11をレンズ系1と固体撮像素
子3の間に挿入した状態で撮像目標を撮像すると撮像目
標からの光線は図3のように固体撮像素子3の受光面上
に結像するが、フィルタδ12をレンズ系1と固体撮像
素子3の間に挿入した状態で同じ撮像目標を撮像すると
撮像目標からの光線は図4のように固体撮像素子3の受
光面上で結像しない。フィルタγ11及びフィルタδ1
2の厚さをd、フィルタγ11の屈折率をnγ、フィル
タδ12の屈折率をnδ、固体撮像素子3の受光面に対
し垂直な平行光線がレンズ系1に入射した際、フィルタ
γ11及びフィルタδ12への光線の最大入射角をiと
した時、フィルタγ11とフィルタδ12をそれぞれ使
用した時の結像位置の差は、(10)式及び(11)式
から求まる値の差の絶対値|ζγ−ζδ|である。When the image pickup target is imaged with the filter γ11 inserted between the lens system 1 and the solid-state image pickup device 3, the light beam from the image pickup target forms an image on the light-receiving surface of the solid-state image pickup device 3 as shown in FIG. When the same imaging target is imaged with the filter δ12 inserted between the lens system 1 and the solid-state imaging device 3, the light rays from the imaging target do not form an image on the light-receiving surface of the solid-state imaging device 3 as shown in FIG. Filter γ11 and filter δ1
When the thickness of 2 is d, the refractive index of the filter γ11 is nγ, the refractive index of the filter δ12 is nδ, and parallel rays perpendicular to the light receiving surface of the solid-state image sensor 3 are incident on the lens system 1, the filter γ11 and the filter δ12. Where i is the maximum incident angle of the ray on the filter, the difference between the imaging positions when the filter γ11 and the filter δ12 are used is the absolute value of the difference between the values obtained from the equations (10) and (11) | ζγ −ζδ |.
【0021】[0021]
【数10】 [Equation 10]
【0022】[0022]
【数11】 [Equation 11]
【0023】光学系の焦点深度をεとした時、(12)
式を満足していれば、フィルタδ12を使用した状態で
撮像目標を光学系の視野内にいれ受光光線を蓄積する
と、像がぼけることにより像の持つ光強度分布が均一化
され、固体撮像素子3の各画素が蓄積する受光量はそれ
ぞれ等しくなる。When the focal depth of the optical system is ε, (12)
If the expression is satisfied, when the image pickup target is placed in the field of view of the optical system while the filter δ12 is used and the received light rays are accumulated, the image is blurred and the light intensity distribution of the image is made uniform. The amount of received light accumulated in each pixel of 3 becomes equal.
【0024】[0024]
【数12】 [Equation 12]
【0025】記憶装置5に記憶した各画素ごとの出力値
は撮像目標からの光線を各画素が等しく一定量受光した
値なので、フィルタγ11を使用して撮像する際にその
出力信号を基に感度補正を行うとノイズが少ない出力画
像を表示装置7に表示できる。フィルタγ11及びフィ
ルタγ12が(12)式を満足していない場合、感度補
正を行うと、記憶装置5に記憶する固体撮像素子3の各
画素ごとの出力値は像の持つ不均一な光強度分布を記憶
することになる。その出力値を基に感度補正を行うと、
出力画像に記憶装置5に記憶した不均一な光強度分布が
残像として生じてしまい、かえって出力画像が劣化して
しまう。そのために、(12)式の関係を満足するよう
なフィルタδ12を用意する必要がある。感度補正が上
記の方法で行われる以外が従来の赤外線撮像装置と同様
に動作する。Since the output value for each pixel stored in the storage device 5 is a value in which the light rays from the image pickup target are equally received by each pixel by a fixed amount, when the image is picked up using the filter γ11, the sensitivity is based on the output signal. When correction is performed, an output image with less noise can be displayed on the display device 7. When the filters γ11 and γ12 do not satisfy the expression (12), when sensitivity correction is performed, the output value for each pixel of the solid-state image sensor 3 stored in the storage device 5 has an uneven light intensity distribution of the image. Will be remembered. When sensitivity correction is performed based on the output value,
The non-uniform light intensity distribution stored in the storage device 5 is generated as an afterimage in the output image, which rather deteriorates the output image. Therefore, it is necessary to prepare the filter δ12 that satisfies the relationship of the expression (12). The operation is similar to that of the conventional infrared imaging device except that the sensitivity correction is performed by the above method.
【0026】[0026]
【発明の効果】以上のように、この発明によれば厚みの
異なるフィルタを交換機構により交換することにより、
撮像目標から固体撮像素子が蓄積する受光量を各画素で
等しくし、その際の各画素の出力値を記憶する。その記
憶した出力値を基に感度補正が行われるので、ノイズの
少ない出力画像が得られる。As described above, according to the present invention, by exchanging filters having different thicknesses by the exchanging mechanism,
The amount of light received by the solid-state image sensor from the imaging target is made equal for each pixel, and the output value of each pixel at that time is stored. Since the sensitivity correction is performed based on the stored output value, an output image with less noise can be obtained.
【0027】以上のように、もう1つの発明によれば屈
折率の異なるフィルタを交換機構により交換することに
より、撮像目標から固体撮像素子が蓄積する受光量を各
画素で等しくし、その際の各画素の出力値を記憶する。
その記憶した出力値を基に感度補正が行われるので、ノ
イズの少ない出力画像が得られる。As described above, according to another aspect of the present invention, by exchanging the filters having different refractive indexes by the exchanging mechanism, the amount of light received by the solid-state image pickup device from the image pickup target is made equal in each pixel, and in that case. The output value of each pixel is stored.
Since the sensitivity correction is performed based on the stored output value, an output image with less noise can be obtained.
【図1】この発明の実施例1を示す赤外線撮像装置の構
成図である。FIG. 1 is a configuration diagram of an infrared imaging device showing a first embodiment of the present invention.
【図2】この発明の実施例1を示す赤外線撮像装置の構
成図である。FIG. 2 is a configuration diagram of an infrared imaging device showing Embodiment 1 of the present invention.
【図3】この発明の実施例2を示す赤外線撮像装置の構
成図である。FIG. 3 is a configuration diagram of an infrared imaging device showing a second embodiment of the present invention.
【図4】この発明の実施例2を示す赤外線撮像装置の構
成図である。FIG. 4 is a configuration diagram of an infrared imaging device showing a second embodiment of the present invention.
【図5】従来の赤外線撮像装置の一実施例を示す構成図
である。FIG. 5 is a configuration diagram showing an embodiment of a conventional infrared imaging device.
1 レンズ系 2 フィルタ 3 固体撮像素子 4 増幅器 5 記憶装置 6 処理装置 7 表示装置 8 シャッタ 9 フィルタα 10 フィルタβ 11 フィルタγ 12 フィルタδ 1 Lens System 2 Filter 3 Solid-state Image Sensor 4 Amplifier 5 Storage Device 6 Processing Device 7 Display Device 8 Shutter 9 Filter α 10 Filter β 11 Filter γ 12 Filter δ
Claims (2)
線を集光するレンズ系と、上記レンズ系が集光した光線
の光路上に位置する第1のフィルタと、上記レンズ系と
第1のフィルタを透過した光線が受光面上で結像する位
置にある固体撮像素子からなる赤外線撮像装置におい
て、その厚さが上記第1のフィルタの厚さと異なる第2
のフィルタと、上記第1のフィルタと第2のフィルタを
交換して挿入出来る機構を有し、上記第1のフィルタと
第2のフィルタは、第1のフィルタの厚さをdα、第2
のフィルタの厚さをdβ、第1のフィルタと第2のフィ
ルタβの屈折率をn、上記固体撮像素子の受光面に対し
垂直な平行光線が上記レンズ系に入射した際、第1のフ
ィルタ及び第2のフィルタへの光線の最大入射角をi、
上記光学系の焦点深度をεとした時、(1)式、(2)
式、および(3)式の関係を満足するようにしたことを
特徴とする赤外線撮像装置。 【数1】 【数2】 【数3】 1. A lens system for condensing light rays reflected or radiated by an external target, a first filter located on the optical path of the light rays condensed by the lens system, the lens system and the first filter. In an infrared imaging device including a solid-state imaging device at a position where a light beam that has passed through a filter forms an image on a light receiving surface, a second thickness different from that of the first filter is provided.
And a mechanism for inserting the first filter and the second filter by exchanging the first filter and the second filter. The first filter and the second filter have a thickness of the first filter of dα and a second filter of the second filter.
The thickness of the filter is dβ, the refractive indices of the first filter and the second filter are n, and when a parallel light beam perpendicular to the light receiving surface of the solid-state image sensor enters the lens system, And the maximum angle of incidence of the ray on the second filter is i,
When the depth of focus of the optical system is ε, equations (1) and (2)
An infrared imaging device characterized by satisfying the relationships of equation (3) and equation (3). [Equation 1] [Equation 2] [Equation 3]
線を集光するレンズ系と、上記レンズ系が集光した光線
の光路上に位置する第1のフィルタと、上記レンズ系と
第1のフィルタを透過した光線が受光面上で結像する位
置にある固体撮像素子からなる赤外線撮像装置におい
て、屈折率が上記第1のフィルタの屈折率と異なる第2
のフィルタと、上記第1のフィルタと第2のフィルタを
交換して挿入出来る機構を有し、上記第1のフィルタと
第2のフィルタは、厚さが共にd、第1のフィルタの屈
折率をnγ、第2のフィルタの屈折率をnδ、上記固体
撮像素子の受光面に対し垂直な平行光線が上記レンズ系
に入射した際、第1のフィルタ及び第2のフィルタへの
光線の最大入射角をi、上記光学系の焦点深度をεとし
た時、(4)式及び(5)式、(6)式の関係を満足す
るようにしたことを特徴とする赤外線撮像装置。 【数4】 【数5】 【数6】 2. A lens system for condensing light rays reflected or radiated by an external target, a first filter located on the optical path of the light rays condensed by the lens system, the lens system and the first lens system. In an infrared imaging device including a solid-state imaging device at a position where a light beam that has passed through a filter forms an image on a light receiving surface, a second refractive index different from the refractive index of the first filter is used.
And a mechanism capable of replacing and inserting the first filter and the second filter. The first filter and the second filter both have a thickness d and a refractive index of the first filter. Nγ, the refractive index of the second filter is nδ, and when a parallel light ray perpendicular to the light receiving surface of the solid-state image sensor is incident on the lens system, the maximum incidence of the light ray on the first filter and the second filter An infrared imaging device, characterized in that, when an angle is i and a depth of focus of the optical system is ε, the relationships of expressions (4), (5), and (6) are satisfied. [Equation 4] [Equation 5] [Equation 6]
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4219048A JPH0666631A (en) | 1992-08-18 | 1992-08-18 | Infrared image sensor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4219048A JPH0666631A (en) | 1992-08-18 | 1992-08-18 | Infrared image sensor |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0666631A true JPH0666631A (en) | 1994-03-11 |
Family
ID=16729447
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP4219048A Pending JPH0666631A (en) | 1992-08-18 | 1992-08-18 | Infrared image sensor |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0666631A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2009107471A1 (en) * | 2008-02-29 | 2009-09-03 | 日本電気株式会社 | Infrared imaging device and fixed pattern noise correction method |
-
1992
- 1992-08-18 JP JP4219048A patent/JPH0666631A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2009107471A1 (en) * | 2008-02-29 | 2009-09-03 | 日本電気株式会社 | Infrared imaging device and fixed pattern noise correction method |
JP2009207072A (en) * | 2008-02-29 | 2009-09-10 | Nec Corp | Infrared imaging apparatus and fixed pattern noise correction method |
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