JPH05236352A - Sensitivity correcting method for infrared image pickup device - Google Patents
Sensitivity correcting method for infrared image pickup deviceInfo
- Publication number
- JPH05236352A JPH05236352A JP4030599A JP3059992A JPH05236352A JP H05236352 A JPH05236352 A JP H05236352A JP 4030599 A JP4030599 A JP 4030599A JP 3059992 A JP3059992 A JP 3059992A JP H05236352 A JPH05236352 A JP H05236352A
- Authority
- JP
- Japan
- Prior art keywords
- solid
- image pickup
- optical system
- sensitivity
- state image
- 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.)
- Pending
Links
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- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
- Lenses (AREA)
- Transforming Light Signals Into Electric Signals (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感度補正方法に関するもの
である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensitivity correction method for 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３は従来の赤外線撮像装置の感度補正
方法の構成例であり、図において、１は光学系、２は上
記光学系１によって集光された光線を受光する固体撮像
素子、３は上記固体撮像素子２から出力された電気信号
を増幅する増幅器、４は上記増幅器３によって増幅され
た電気信号を記憶する記憶装置、５は上記増幅器３から
出力される電気信号と上記記憶装置４によって記憶され
た電気信号を演算処理する処理装置、６は上記処理装置
５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２の前面に位置するシャ
ッタである。2. Description of the Related Art FIG. 3 shows a configuration example of a sensitivity correction method for a conventional infrared image pickup device. In the figure, 1 is an optical system, 2 is a solid-state image pickup device for receiving a light beam condensed by the optical system 1, Reference numeral 3 is an amplifier for amplifying the electric signal output from the solid-state imaging device 2, 4 is a storage device for storing the electric signal amplified by the amplifier 3, and 5 is an electric signal output from the amplifier 3 and the storage device. A processing device for arithmetically processing the electrical signal stored by 4; a display device 6 for displaying the electrical signal processed by the processing device 5 as an image; and a shutter 8 located on the front surface of the solid-state image sensor 2.
【０００３】従来の赤外線撮像装置は上記のように構成
され、以下のような動作によって感度を補正する。光学
系１によって集光された光線は、固体撮像素子２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３によって増幅された後、表示
装置６によって画像として表示される。固体撮像素子２
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
２の前面に設置したシャッタ８を閉じて固体撮像素子２
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４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２で受光し電気信号を出力する。処理
装置５においてこの出力された電気信号から記憶装置４
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６に画像として表示する。The conventional infrared image pickup device is constructed as described above, and the sensitivity is corrected by the following operation. The light beam condensed by the optical system 1 is received by the solid-state image sensor 2, and the image is output to the outside as an electric signal. The output electric signal is amplified by the amplifier 3 and then displayed as an image by the display device 6. Solid-state image sensor 2
, The output value 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 2 is closed to close the solid-state image sensor 2
A uniform light beam is made incident on the pixel, and the output signal for each pixel at that time is stored in the storage device 4 in advance. Next, when capturing an image of the target object, the shutter 8 is opened and the light beam from the target object is received by the solid-state image sensor 2 and an electric signal is output. The storage device 4 uses the output electric signal in the processing device 5.
The sensitivity is corrected by subtracting the electric signal stored in advance, and is displayed as an image on the display device 6.
【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
外線撮像装置の感度補正方法においては、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
のシャッタの輝度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シャッタの輝度は撮像目標輝度と
異なってしまう。そのため画像上の照度が実際と異な
り、感度補正が十分に行われず、表示装置６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 method for correcting the sensitivity of the infrared image pickup device as described above, a uniform light beam is obtained using the shutter 8 when the sensitivity is corrected. The brightness of the shutter 8 is different from the target brightness of the image pickup. Further, the temperature of the shutter 8 rises during use of the infrared image pickup device, so that the brightness of the shutter becomes different from the target brightness of the image pickup. Therefore, the illuminance on the image is different from the actual one, the sensitivity correction is not sufficiently performed, and there is a problem that noise is generated in the image displayed by the display device 6.
【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、撮像目標が画面上で形成す
る照度分布を平均化した照度を固体撮像素子全面に形成
し、その際の固体撮像素子の各画素ごとの出力値を記憶
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 to solve the above-mentioned problems, and an illuminance obtained by averaging the illuminance distribution formed on the screen by the image pickup target is formed on the entire surface of the solid-state image pickup element, and at that time An object of the present invention is to obtain an image with less noise by performing an appropriate sensitivity correction by storing the output value of each pixel of the solid-state image sensor in the storage device and performing the 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
像装置の感度補正方法は、光学系と固体撮像素子の間に
光学系が集光した光線を平行光に変換するコンバージョ
ンレンズを挿入するものである。A sensitivity correction method for an infrared imaging device according to the present invention inserts a conversion lens for converting a light beam condensed by an optical system into parallel light between an optical system and a solid-state imaging device. Is.
【０００７】[0007]
【作用】この発明における赤外線撮像装置の感度補正方
法は、光学系と固体撮像素子の間にコンバージョンレン
ズを挿入する事により、光学系によって集光された光線
を平行光に変換し、撮像目標が画面上で形成する照度分
布を平均化した照度を固体撮像素子前面に形成し、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。According to the sensitivity correcting method for the infrared image pickup device of the present invention, the conversion target lens is inserted between the optical system and the solid-state image pickup device to convert the light beam condensed by the optical system into parallel light, and the image pickup target is Since the illuminance obtained by averaging the illuminance distribution formed on the screen is formed on the front surface of the solid-state image sensor, and the sensitivity correction is performed based on the output signal, noise in the output image is reduced.
【０００８】[0008]
【実施例】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（ａ）は撮像時の配置状態を、ま
た図１（ｂ）は感度補正時の配置状態を示す図であり、
図１において、１〜６は従来例と同一の名称と機能を有
する部分、７は上記光学系１の集光位置に焦点を持ち、
光学系１が集光した光線を平行光に変換するコンバージ
ョンレンズである。EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1A is a diagram showing an arrangement state during image pickup, and FIG. 1B is a diagram showing an arrangement state during sensitivity correction,
In FIG. 1, 1 to 6 are portions having the same names and functions as those of the conventional example, and 7 is a focal point at the condensing position of the optical system 1,
It is a conversion lens that converts the light beam condensed by the optical system 1 into parallel light.
【０００９】この発明における赤外線撮像装置の感度補
正方法は上記のように構成され、以下のように動作す
る。感度補正を行なうとき、撮像目標が視野内にある状
態で固体撮像素子２を光学系１の光軸上で、光学系１と
反対方向に移動させると共に、コンバージョンレンズ７
をその焦点が光学系１の集光位置に来るよう挿入する
（図１（ｂ））。コンバージョンレンズ７は光学系１が
集光した光線を平行光に変換し、固体撮像素子２に入射
させる。光学系１が像面上で形成する照度分布は撮像目
標により任意に分布するが、コンバージョンレンズ７は
この像面上の１点に集光した光線を均一な平行光として
固体撮像素子２に入射させ、この動作を像面上全ての点
で実施しているため、固体撮像素子２上では像面全面で
のエネルギを平均化したエネルギすなわち照度が固体撮
像素子２全面で得られる。また、コンバージョンレンズ
７自体は赤外線をほとんど放射しないためコンバージョ
ンレンズ７の温度の変化によっても固体撮像素子２上の
照度はほとんど変化しない。この状態で各画素ごとの出
力値を記憶装置４に記憶する。記憶装置４に記憶した各
画素ごとの出力値は撮像目標輝度に近い均一な光線を固
体撮像素子２で受光した際のものなので、その出力信号
を基に感度補正を行いノイズが少ない出力画像を表示装
置６に表示できる。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。The sensitivity correction method for the infrared image pickup device according to the present invention is configured as described above and operates as follows. When performing the sensitivity correction, the solid-state imaging device 2 is moved in the direction opposite to the optical system 1 on the optical axis of the optical system 1 while the imaging target is within the field of view, and the conversion lens 7 is used.
Is inserted so that its focal point is located at the focus position of the optical system 1 (FIG. 1 (b)). The conversion lens 7 converts the light beam condensed by the optical system 1 into parallel light and makes it enter the solid-state image sensor 2. Although the illuminance distribution formed by the optical system 1 on the image plane is arbitrarily distributed according to the image pickup target, the conversion lens 7 makes the light beam condensed at one point on the image plane enter the solid-state image sensor 2 as uniform parallel light. Since this operation is performed at all points on the image plane, the energy obtained by averaging the energy on the entire plane of the image plane, that is, the illuminance, can be obtained on the entire plane of the solid state image sensor 2. Further, since the conversion lens 7 itself hardly emits infrared rays, the illuminance on the solid-state image sensor 2 hardly changes even if the temperature of the conversion lens 7 changes. In this state, the output value for each pixel is stored in the storage device 4. Since the output value for each pixel stored in the storage device 4 is obtained when the solid-state image sensor 2 receives a uniform light beam close to the image capturing target brightness, sensitivity correction is performed based on the output signal to obtain an output image with less noise. It can be displayed on the display device 6. It operates in the same manner as the conventional infrared imaging device except that the sensitivity correction is performed by the above method.
【００１０】この発明の実施するためのコンバージョン
レンズ及びその使用方法は、光学系や固体撮像素子によ
り、様々な設計例が考えられるが、図２に光学系のＦ値
１．５、固体撮像素子φ１ｍｍの赤外線撮像装置用のコ
ンバージョンレンズの一設計例を示す。図において、Ｓ
１〜Ｓ４は面番号である。図の表において、曲率半径は
各面番号に対応する曲率半径を図中左側凸を＋、右側凸
を−で記載し、面間隔は各面番号に対応する面の図中右
側次の面までの光軸上の距離を表わし、屈折率は各面番
号に対応する面の図中右側の媒質の屈折率を表わしてい
る。補正時には固体撮像素子を光学系の光軸上光学系と
反対方向に５１．３９ｍｍ移動させ、固体撮像素子から
３０．２２ｍｍの位置にコンバージョンレンズのＳ４面
がくるよう配置することにより、像目標が像面上で形成
する照度分布を平均化した照度を固体撮像素子前面に形
成することができる。Various design examples of the conversion lens and the method of using the same for implementing the present invention can be considered depending on the optical system and the solid-state image pickup device. 1 shows a design example of a conversion lens for a φ1 mm infrared imaging device. In the figure, S
1 to S4 are surface numbers. In the table in the figure, the radius of curvature is indicated by + for the left-side convex and − for the right-side convex in the figure for the radius of curvature corresponding to each surface number, and the surface interval is to the next surface on the right side in the figure of the surface corresponding to each surface number. Represents the distance on the optical axis, and the refractive index represents the refractive index of the medium on the right side in the figure of the surface corresponding to each surface number. At the time of correction, by moving the solid-state image sensor by 51.39 mm in the direction opposite to the optical system on the optical axis of the optical system, and arranging so that the S4 surface of the conversion lens comes to a position of 30.22 mm from the solid-state image sensor, the image target becomes The illuminance obtained by averaging the illuminance distribution formed on the image plane can be formed on the front surface of the solid-state image sensor.
【００１１】なお上記実施例では感度補正時、固体撮像
素子２を光学系１の光軸上を移動させてコンバージョン
レンズ７の焦点が光学系１の集光位置にくるようにした
が、光学系１を移動させて固体撮像素子２との相対位置
を変化させても良い。In the above embodiment, when the sensitivity is corrected, the solid-state image sensor 2 is moved along the optical axis of the optical system 1 so that the focal point of the conversion lens 7 comes to the focus position of the optical system 1. 1 may be moved to change the relative position to the solid-state image sensor 2.
【００１２】[0012]
【発明の効果】以上のように、コンバージョンレンズを
光学系と固体撮像素子の間に挿入し、光学系が集光した
光線を平行光に変換することにより、撮像目標輝度に近
い均一な光線を固体撮像素子に入射でき感度補正が行わ
れるので、ノイズの少ない出力画像が得られる。As described above, by inserting the conversion lens between the optical system and the solid-state image pickup device and converting the light beam condensed by the optical system into parallel light, a uniform light beam close to the image pickup target brightness is obtained. Since the light can be incident on the solid-state image sensor and the sensitivity is corrected, an output image with less noise can be obtained.
【図１】この発明の一実施例を示す赤外線撮像装置の感
度補正方法の構成図である。FIG. 1 is a configuration diagram of a sensitivity correction method for an infrared imaging device according to an embodiment of the present invention.
【図２】コンバージョンレンズの一設計例を示す図であ
る。FIG. 2 is a diagram showing a design example of a conversion lens.
【図３】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. 3 is a configuration diagram showing an embodiment of a conventional infrared imaging device.
１ 光学系 ２ 固体撮像素子 ３ 増幅器 ４ 記憶装置 ５ 処理装置 ６ 表示装置 ７ コンバージョンレンズ ８ シャッタ DESCRIPTION OF SYMBOLS 1 Optical system 2 Solid-state image sensor 3 Amplifier 4 Storage device 5 Processing device 6 Display device 7 Conversion lens 8 Shutter
Claims (1)
線を集光する光学系と、上記光学系を透過した光線を受
光する位置に有する固体撮像素子とを備えた赤外線撮像
装置の感度補正方法において、上記固体撮像素子と光学
系との相対位置を移動させるとともに、上記光学系と上
記固体撮像素子の間に上記光学系が集光した光線を平行
光に変換するコンバージョンレンズを挿入することによ
って、上記赤外線撮像装置の固体撮像素子上に均一な照
度分布を得ることを特徴とする赤外線撮像装置の感度補
正方法。1. A sensitivity correction method for an infrared imaging apparatus, comprising: an optical system for condensing light rays reflected or emitted by an external target; and a solid-state imaging device provided at a position for receiving light rays transmitted through the optical system. In, by moving the relative position of the solid-state image sensor and the optical system, by inserting a conversion lens for converting the light beam condensed by the optical system into parallel light between the optical system and the solid-state image sensor. A sensitivity correction method for an infrared imaging device, characterized in that a uniform illuminance distribution is obtained on a solid-state imaging device of the infrared imaging device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4030599A JPH05236352A (en) | 1992-02-18 | 1992-02-18 | Sensitivity correcting method for infrared image pickup device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4030599A JPH05236352A (en) | 1992-02-18 | 1992-02-18 | Sensitivity correcting method for infrared image pickup device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05236352A true JPH05236352A (en) | 1993-09-10 |
Family
ID=12308333
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4030599A Pending JPH05236352A (en) | 1992-02-18 | 1992-02-18 | Sensitivity correcting method for infrared image pickup device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05236352A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001141993A (en) * | 1999-11-11 | 2001-05-25 | Mitsubishi Electric Corp | Infrared optical system |
| JP2008107448A (en) * | 2006-10-24 | 2008-05-08 | Sony Corp | Imaging apparatus |
| JP2009204655A (en) * | 2008-02-26 | 2009-09-10 | Tokina:Kk | Lens system |
-
1992
- 1992-02-18 JP JP4030599A patent/JPH05236352A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001141993A (en) * | 1999-11-11 | 2001-05-25 | Mitsubishi Electric Corp | Infrared optical system |
| JP2008107448A (en) * | 2006-10-24 | 2008-05-08 | Sony Corp | Imaging apparatus |
| JP2009204655A (en) * | 2008-02-26 | 2009-09-10 | Tokina:Kk | Lens system |
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