JP2004117309A - Multi-color infrared imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an infrared imaging device allowing the determination of the qualities and conditions of materials for an object. <P>SOLUTION: An infrared emission energy Eλ from the object 1 is injected to a sensor 5 of a multi-color infrared imaging device 6 via an optical filter 4 having a plurality of wavelength spectrum ranges. A computing means 14 finds a true temperature T<SB>0</SB>and a background temperature Ta of the object 1 in accordance with emissivity values for the plurality of materials previously stored in a storage means 13. The qualities and conditions of the plurality of materials are determined via the computing means. <P>COPYRIGHT: (C)2004,JPO

Description

ここで
Ｔ_０：被写体温度
Ｔａ：背景温度
ε_０：放射率
ｎ：１次近似した指数定数
である。
【０００５】
上式の演算は近似による温度値の合せ込みのため広い範囲の温度を測定する場合、精度を要求する場合は問題が残る。
【０００６】
更に、近赤外線の３波長で同視野を同時に観測できる広視野用のサーベイ観測用多色同時赤外線カメラ「ＳＩＲＩＵＳ」（Ｓｉｍｕｌｔａｎｅｏｕｓ−ｃｏｌｏｒ　Ｉｎｆｒａｒｅｄ　Ｉｍａｇｅｒｆｏｒ　Ｕｎｂｉａｓｅｄ　Ｓｕｒｖｅｙ）として検出器に１０２４×１０２４素子のＨｇｃｄＴｅ赤外アレイを３個装備させ、波長１．２５μｍ、１．６５μｍ、２．１μｍで視野同時撮像する赤外線カメラ（非特許文献１参照）が開示されている。
【０００７】
【非特許文献１】
長嶋千恵　外１５名　サーベイ　観測用多色同時赤外線カメラＳＩＲＩＵＳ
平成１４年９月２６日　インターネット＜ｈｔｔｐ／／ｏｐｔｉｋ２．ｍｔｋ．ｎａｏ．ａｃ．ｊｐ／｀ｈｉｄｅ／ｓ−ｐｏｓｔｅｒ９８０２４．ｐｄｆ＞
【０００８】
【発明が解決しようとする課題】
上述の従来の赤外線撮像装置では検出部１９の光学系２５に被写体１から入射した赤外線量の大小を単純に温度値に変換しているので被写体１の放射率が異なると、真温度が検出されない課題を有していた。
また、被写体１の放射率が解っていたとしても、天空等から放射された赤外光が被写体表面で反射した外乱要因を含む赤外線が赤外線撮像装置内に入射するため、これら外乱要因を含んだ赤外線量での演算処理によって間違った温度値を検出してしまう課題を有していた。
【０００９】
更に、非特許文献１に開示された多色用同時赤外線カメラでは光学系にビームスプリッタを用いて３個のセンサに同視野を同時に入射させる様にしているため装置が大型化し、センサ数も多くなって汎用の赤外線撮像装置には向かない課題を有している。
【００１０】
本発明は叙上の課題を解消するために成されたもので、本発明が解決しようとする課題は放射率の異なる被写体の放射率及び真温度を測定し、被写体物質の材質やその状態が検出可能な赤外線撮像装置を得る様に成したものである。
【００１１】
【課題を解決するための手段】
第１の本発明は被写体１の放射エネルギーを測定して、被写体１の温度計測を行なう多色赤外線撮像装置６に於いて、被写体１と赤外線撮像装置６の検出器５間に被写体１からの複数の赤外線波長範囲を切換え検出器１に入射させる光学帯域通過濾波手段４と、赤外線の複数波長範囲内で被写体１の複数物質或はその状態の放射率値を格納した記憶手段１５と、複数の赤外線波長範囲内の被写体１の赤外線量を測定し、記憶手段１５に格納した複数物質或は状態の放射率値を基に被写体１の温度及び背景２の温度を演算する演算手段１４とを有し、この演算手段１４で求めた被写体１の温度から被写体１の物質或はその状態を判別する様に成したことを特徴とする多色赤外線撮像装置としたものである。
【００１２】
第２の本発明は複数の赤外線波長範囲が第１乃至第３の赤外線波長範囲である様に成したものである。
第３の本発明は被写体の複数の物質或はその状態はコンクリート、ガラス等の異なる物質或は、水、氷の如き物体の変化状態を示す様に成したものである。
【００１３】
斯かる、本発明の多色赤外線撮像装置に依れば複数の物質の材質やその変化状態を判別可能なものが得られる。
【００１４】
【発明の実施の形態】
以下、本発明の多色赤外線撮像装置の１形態例を図１乃至図３を用いて説明する。尚、図４との対応部分には同一符号を付して重複説明を省略する。
【００１５】
図１は本発明の撮像装置に入射するエネルギーを説明するための説明図、図２は本発明の多色赤外線撮像装置の１形態例を示すブロック図、図３は本発明の多色赤外線撮像装置のフローチャートである。
【００１６】
図１は一般的な測定環境における赤外線放射状態を示すもので被写体１の表面温度をＴ_０、被写体１の波長領域λでの放射率をε、大気等の反射による放射源２の背景温度をＴａ、ｆを波長領域λの黒体に対する黒体放射エネルギーとする。ここで物体の温度と赤外線放射の関係は一般にプランク（Ｐｌａｎｃｋ）　の法則で数２で与えられる。
【数２】
Ｍλ＝Ｃ_１／λ^５〔ｅｘｐ（Ｃ_２／λ_Ｔ）−１〕^−１・・・（４）
ここで
Ｍλ：分光放射発散度（ｗ，ｃｍ^−２　　μｍ^−１）
λ：波長（μｍ）
Ｔ：絶対温度（Ｋ）
Ｃ_１Ｃ_２：定数
である。
【００１７】
この（４）式は放射率が１の黒体に対して成り立ち、黒体から放射される全放射エネルギーＭは数３のステファン−ボルツマン（Ｓｔｅｆａｎ−Ｂｏｌｔｚｍａｎｎ）法則である絶対温度Ｔの４乗に比例する。
【００１８】
【数３】
Ｍ＝σＴ^４〔ｗ，ｃｍ^−２〕・・・（５）
σ：Ｓｔｅｆａｎ−Ｂｏｌｔｚｍａｎｎ定数
この法則から被写体１から放射される放射エネルギーの強度即ち、赤外線量を測定することで被写体の温度を検出することになる。
【００１９】
図１に示す本発明の多色赤外線撮像装置６は被写体１からの出射エネルギーελ・ｆ（Ｔ_０・λ）と、放射源の大気２等の外乱要因で生ずる被写体１から生ずる放射エネルギー（１−ελ）・ｆ（Ｔａ）の和、即ち数４の赤外線量が入射エネルギーをＥλとして光学通過濾波手段（ＢＰＦ）４を介して赤外撮像装置６のセンサ５に入射される様に成されている。
【００２０】
【数４】

【００２１】
本発明に用いる光学的ＢＰＦ４は少なくとも第１乃至第３の波長範囲λ_１，λ_２，λ_３の帯域のみを通過可能に選択し、これら第１〜第３の波長範囲λ_１〜λ_３を択一的に選択可能と成されている。
【００２２】
以下、図２を用いて本発明の多色赤外線撮像装置の構成を３波長の３色温度計を用いた構成として説明する。
【００２３】
図２に於いて、被写体１からの入射エネルギーＥλは窓材１８から入射した赤外光を垂直駆動ミラー８及び水平駆動ミラー９で被写体１の像を水平及び垂直走査し、対物レンズ１０で集光した光軸上に光学通過濾波手段（ＢＰＦ）４を配設する。
【００２４】
この光学的ＢＰＦ４に用いる波長帯域は被写体１の種類に応じて選択される。例えば、建物のガラスの様な物質をセンサとしてＩｎＳｂ等を用いて検出する場合は４．８〜５．２μｍのＢＰＦが用いられ、被写体がタイル、コンクリート等の反射率の低い、且つ放射率の高い温度測定時等では５〜８μｍの波長範囲等が選択される。
【００２５】
また、本例では光学的ＢＰＦ４として２枚のフィルター１及びフィルター２を切換えることが出来る構成とし、フィルターなしと２種類のフィルター１及びフィルター２とで合計３通りの赤外線波長範囲λ_１，λ_２，λ_３を切換えることが出来る様に構成している。これにより１台で３波長の計測が可能であり、センサ５の個体差を除くことが出来る。
【００２６】
光学的ＢＰＦ４を通過した赤外線エネルギーＥλは１つのＨｇｃｄＴｅ等のセンサ５に入射された後に信号増幅器１１で増幅後にアナログ−デジタル変換器（Ａ／Ｄ）１２でデジタルデータに変換された後に、マイクロコンピュータ（ＣＰＵ）等の演算手段１４に供給されて記憶手段（メモリ）１３に格納した物質毎の放射率を基に所定の後述する演算を行なって、真温度の演算が行なわれ、ディスプレイ１６やレコーダ１７に温度データが出力されて、表示や印刷が行なわれる。尚、１５はＰＣＵ１４を介してメモリ１３に放射率値等を入力するための操作部である。
【００２７】
上述の多色赤外線撮像装置６では記憶手段１３内に入力手段１５を介して予め３種類の所定波長範囲での対象物質及びその状態の放射率ελを記憶させておき、演算手段を利用して真温度の演算が行なわれる。以下、本発明の動作を図３を用いて説明する。
【００２８】
図３は演算手段１４で真温度演算を行なって被写体１の物質の材質やその状態を正確に判定して、把握を行なうためのフローチャートを示すものである。
【００２９】
図３に於いて、第１ステップＳ_１では第１波長範囲（λ_１）の第１物質（Ａ）或はその状態の放射率値ε_１λを測定（又はサーチ）して入力手段１５とＣＰＵ１４を介してメモリ１３に書き込む。
【００３０】
第２ステップＳ_２では第１の波長範囲（λ_１）の第２の物質（Ｂ）或はその状態の放射率値ε_２λを測定（又はサーチ）して入力手段１５とＣＰＵ１４を介してメモリ１３に書き込む。
【００３１】
第３ステップＳ_３では第１の波長範囲（λ_１）の第３の物質（Ｃ）或はその状態の放射率値ε_３λを測定（又はサーチ）して入力手段１５とＣＰＵ１４を介してメモリ１３に書き込む。
【００３２】
第４ステップＳ_４乃至第６ステップＳ_６では第２波長範囲の第１物質乃至第３物質（Ａ），（Ｂ），（Ｃ）或はその状態の放射率値ε_１，ε_２，ε_３を測定（又はサーチ）して入力手段１５とＣＰＵ１４を介してメモリ１３に書き込む。
【００３３】
同様に第７ステップＳ_７乃至第９ステップＳ_９では第３波長範囲の第１物質乃至第３物質（Ａ），（Ｂ），（Ｃ）或はその状態の放射率値ε_１，ε_２，ε_３を測定（又はサーチ）して入力手段１５とＣＰＵ１４を介してメモリ１３に書き込む。
【００３４】
上記第１ステップＳ_１乃至第９ステップＳ_９によってメモリ１３内には第１乃至第３の波長範囲λ_１〜λ_３の範囲内に第１物質Ａ、第２物質Ｂ、第３物質Ｃ或はこれらの変化状態をを表す、例えば水、氷等の状態での放射率ε_１，ε_２，ε_３が下記の様に格納される。
【００３５】
ε_１（λ_１），ε_１（λ_２），ε_１（λ_３）‥‥（Ａ）第１物質
ε_２（λ_１），ε_２（λ_２），ε_２（λ_３）‥‥（Ｂ）第２物質
ε_３（λ_１），ε_３（λ_２），ε_３（λ_３）‥‥（Ｃ）第３物質
【００３６】
次に第１０ステップＳ_１０に示す様に第１乃至第３の波長範囲の第１乃至第３物質Ａ，Ｂ，Ｃより成る被測定体１の赤外線量Ｅλｎ＝Ｅλ_１，Ｅλ_２，Ｅλ_３を光学ＢＰＦ４を順次切換えて測定する。
【００３７】
この測定により式（１）より数５式を得る。
【００３８】
【数５】
Ｅλ_１＝ελ_１・ｆ（Ｔ_０・λ_１）＋（１−ελ_１）ｆ（Ｔａ）‥‥（７）
Ｅλ_２＝ελ_２・ｆ（Ｔ_０・λ_２）＋（１−ελ_２）ｆ（Ｔａ）‥‥（８）
Ｅλ_３＝ελ_３・ｆ（Ｔ_０・λ_３）＋（１−ελ_３）ｆ（Ｔａ）‥‥（９）
ここで予めメモリ１３に記憶させた第１物質Ａ或はその状態での放射率値εｎ＝ε_１，ε_２，ε_３‥‥をＣＰＵ１４は第１１ステップＳ_１１の様に（７）〜（９）式に代入演算することで被写体温度Ｔ_０と背景温度Ｔａが未値数値となる。
【００３９】
第１２ステップＳ_１２では第１物質Ａ或はその状態を代入した時の被写体温度Ｔ_０及び背景温度Ｔａは上式（７），（８）の減算から（１０）式を得る。
【００４０】
同様に第１物質Ａ或はその状態を代入した時の被写体温度Ｔ_０及び背景温度Ｔａは上式（７），（９）の減算から（１１）式を得る。
【００４１】
次の第１２ステップＳ_１２では第１１ステップＳ_１１で求めた（１０）及び（１１）式から夫々の被写体温度Ｔ_０の差を求めてΔＴ_０（Ａ）を求める。
【００４２】
上述の第１１ステップＳ_１１及び第１２ステップＳ_１２に於いて第１物質Ａと同様で第２物質Ｂ及び第３物質Ｃ或はその状態についての放射率（Ｂ）のΔＴ_０（Ｂ）及びΔＴ_０（Ｃ）について演算することで第１乃至第３物質Ａ乃至ＣのΔＴ_０（Ａ），ΔＴ_０（Ｂ），ΔＴ_０（Ｃ）を求める。
【００４３】
第１３ステップＳ_１３ではΔＴ_０（Ａ），ΔＴ_０（Ｂ），ΔＴ_０（Ｃ）の値（誤差）が最も小さなものに相当する放射率Ａ，Ｂ，Ｃかを判断し、これらΔＴ_０（Ａ），ΔＴ_０（Ｂ），ΔＴ_０（Ｃ）が最小の値のものが第１４ステップＳ_１４に示す様に所定の被写体１の所定の物質Ａ，Ｂ，Ｃ或はその状態であると判別を行なってエンドに至る。
【００４４】
上述の様に被写体１の材質やその状態を定める場合、被写体１内の放射率が似通っている場合は放射率の違いで判別することが困難となる。然し、温度が全く異なる被写体であれば、被写体の物質或は状態を特定、判別することが可能となる。
【００４５】
例えば上述のΔＴ_０（Ａ），ΔＴ_０（Ｃ）の値が略同じである場合、式７から被写体温度Ｔ_０が求まるから被写体１の状態温度の閾値を超えるか超えないかによって、物質の状態を判別すればよく、例えばこの閾値は物質の液相と固相の凝固点に設定すればよい。
【００４６】
具体的な例を上げれば道路の路面の状態を被写体１とすると、道路の濡れ状態（この場合、水滴があり水と同等）、凍結した状態（氷）を閾値を０℃に選択することで道路の水滴状態或は凍結状態での判別が可能となる。勿論この場合も上述の構成と同様に道路の乾燥、水滴、凍結状態の放射率を測定し、記憶手段に格納して置いてＣＰＵを介して演算すればよいことは明白である。
【００４７】
即ち、乾燥状態と水又は氷の両者の違いは放射率の違いから判別し、水と氷の違いは温度（Ｔ_０）の違いから、凝固点が０℃以下であれば凍結（氷）０℃以上であれば濡れ状態（水）と判別できる。この様に物質の材質の差だけでなく道路の路面の状態の判別等にも本発明では効果を有する。
【００４８】
上述の各形態例では２つの波長での計測で被写体の物質の材質或はその状態を判別しただ３波長以上の複数の波長であっても同様に判別可能である。
【００４９】
【発明の効果】
本発明の多色赤外線撮像装置に依れば外乱の影響の少ない放射率が１でない物質の材質やその状態の判別が可能であり放射率の異なる被写体に於いても真温度や状態温度の閾値を基に物質やその状態を正確に選択可能なものが得られる。
【図面の簡単な説明】
【図１】本発明の入射エネルギー取得方法を説明するための概念図である。
【図２】本発明の多色赤外線撮像装置の１形態例を示すブロック図である。
【図３】本発明の多色赤外線撮像装置の演算手段の演算方法を説明するためのフローチャートである。
【図４】従来の赤外線撮像装置のブロック図である。
【符号の説明】
１‥‥被写体、４‥‥光学通過濾波手段、５‥‥センサ、１３‥‥記憶手段（メモリ）１４‥‥演算手段（ＣＰＵ）、１５‥‥入力手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a multicolor infrared imaging device capable of measuring a true temperature of a subject using a multicolor thermometer, and more particularly to a multicolor infrared imaging device capable of determining a material of a subject substance and its state.
[0002]
[Prior art]
The basic configuration of a conventionally used infrared imaging device (thermography device) 21 is a radiation thermometer with a scanning function added thereto. Generally, as shown in FIG. A detection unit 19 that captures an image in a predetermined field of view 22 and supplies it to a primary or two-dimensional sensor (HgcdTe, PtSi, InSb, etc.) 5 to detect radiant energy from the subject 1 and amplify it by a signal amplifier 11 or the like. And a calculation means 14 such as a CPU (microcomputer) constituting a control section, and a display 16 for displaying the temperature state of the subject 1 in color.
[0003]
Conventionally, the radiant energy measured by the subject 1 is taken into the sensor 5 via a two-wavelength optical pass filter (BPF), and the index n is approximately set as shown in the following equation (1). A method of removing the influence of the rate to derive a function F (T ₀ ) of the true temperature T ₀ of the subject 1 is used.
[0004]
(Equation 1)

Here, T ₀ : subject temperature Ta: background temperature ε ₀ : emissivity n: an exponential constant approximated by first order.
[0005]
In the calculation of the above expression, a problem remains when measuring a wide range of temperatures because of approximation of the temperature value by approximation, and when accuracy is required.
[0006]
Furthermore, a 1024 × 1024 element HgcdTe infrared detector is used as a multicolor simultaneous infrared camera “SIRIUS” (Simultaneous-color Infrared Imagerfor Unbiased Survey) for survey observation for a wide field of view capable of simultaneously observing the same field of view at three wavelengths of near infrared. An infrared camera (see Non-Patent Document 1) equipped with three arrays and simultaneously imaging a visual field at wavelengths of 1.25 μm, 1.65 μm, and 2.1 μm is disclosed.
[0007]
[Non-patent document 1]
Chie Nagashima Outside 15 people Multicolor simultaneous infrared camera SIRIUS for observation
September 26, 2002 Internet <http // optik2. mtk. nao. ac. jp / @ hide / s-poster98024. pdf>
[0008]
[Problems to be solved by the invention]
In the above-described conventional infrared imaging apparatus, the magnitude of the amount of infrared light that has entered the optical system 25 of the detection unit 19 from the subject 1 is simply converted into a temperature value. Therefore, if the emissivity of the subject 1 is different, the true temperature is not detected. Had issues.
Further, even if the emissivity of the subject 1 is known, the infrared light radiated from the sky or the like is reflected on the surface of the subject. There is a problem that an incorrect temperature value is detected by the arithmetic processing with the amount of infrared rays.
[0009]
Furthermore, the multi-color simultaneous infrared camera disclosed in Non-Patent Document 1 uses a beam splitter in the optical system so that the same field of view is simultaneously incident on three sensors. Therefore, there is a problem that is not suitable for a general-purpose infrared imaging device.
[0010]
The present invention has been made in order to solve the above-mentioned problems, and the problem to be solved by the present invention is to measure the emissivity and the true temperature of subjects having different emissivities, and to determine the material of the subject material and its state. This is to obtain a detectable infrared imaging device.
[0011]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a multicolor infrared imaging device 6 for measuring the radiant energy of a subject 1 and measuring the temperature of the subject 1. An optical band-pass filtering means 4 for switching a plurality of infrared wavelength ranges to be incident on the detector 1; a storage means 15 for storing a plurality of substances of the subject 1 or emissivity values of the state within the plurality of infrared wavelength ranges; Calculating means 14 for calculating the temperature of the subject 1 and the temperature of the background 2 based on the emissivity values of a plurality of substances or states stored in the storage means 15 by measuring the amount of infrared light of the subject 1 within the infrared wavelength range of The multicolor infrared imaging apparatus is characterized in that the substance or the state of the subject 1 is determined from the temperature of the subject 1 obtained by the calculating means 14.
[0012]
According to a second aspect of the present invention, the plurality of infrared wavelength ranges are the first to third infrared wavelength ranges.
According to a third aspect of the present invention, a plurality of substances of a subject or their states indicate different substances such as concrete and glass, or change states of objects such as water and ice.
[0013]
According to such a multi-color infrared imaging apparatus of the present invention, it is possible to obtain an apparatus capable of discriminating the materials of a plurality of substances and their change states.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a multicolor infrared imaging apparatus according to the present invention will be described with reference to FIGS. The same reference numerals are given to the portions corresponding to those in FIG.
[0015]
FIG. 1 is an explanatory diagram for explaining energy incident on an image pickup apparatus of the present invention, FIG. 2 is a block diagram showing one embodiment of a multicolor infrared image pickup apparatus of the present invention, and FIG. It is a flowchart of an apparatus.
[0016]
FIG. 1 shows the infrared radiation state in a general measurement environment. The surface temperature of the subject 1 is T ₀ , the emissivity in the wavelength region λ of the subject 1 is ε, and the background temperature of the radiation source 2 due to reflection of the atmosphere or the like is shown. Ta, f is the blackbody radiation energy for the blackbody in the wavelength region λ. Here, the relation between the temperature of the object and the infrared radiation is generally given by Equation 2 according to Planck's law.
(Equation 2)
Mλ = C ₁ / λ ⁵ [exp (C ₂ / λ _T ) −1] ⁻¹ (4)
Here, Mλ: spectral radiation emittance (w, cm ⁻² μm ⁻¹ )
λ: wavelength (μm)
T: Absolute temperature (K)
C ₁ C ₂ : a constant.
[0017]
This equation (4) holds for a black body having an emissivity of 1, and the total radiant energy M radiated from the black body is the fourth power of the absolute temperature T, which is the Stefan-Boltzmann's law of Equation (3). Proportional.
[0018]
[Equation 3]
M = σT ⁴ [w, cm ⁻² ] (5)
σ: Stefan-Boltzmann constant From this rule, the temperature of the subject is detected by measuring the intensity of radiant energy radiated from the subject 1, that is, the amount of infrared rays.
[0019]
The multicolor infrared imaging apparatus 6 of the present invention shown in FIG. 1 has a radiation energy ελ · f (T ₀ λ) from the subject 1 and a radiation energy (1) generated from the subject 1 caused by a disturbance factor such as the atmosphere 2 of the radiation source. −ελ) · f (Ta), that is, the infrared amount of the formula 4 is incident on the sensor 5 of the infrared imaging device 6 through the optical pass filter (BPF) 4 with the incident energy as Eλ. ing.
[0020]
(Equation 4)

[0021]
The optical BPF 4 used in the present invention is selected so as to pass at least only the first to third wavelength ranges λ ₁ , λ ₂ , λ ₃ , and these first to third wavelength ranges λ _{1 to} λ ₃ are selected. It can be selected as an alternative.
[0022]
Hereinafter, the configuration of the multicolor infrared imaging apparatus of the present invention will be described as a configuration using a three-color thermometer of three wavelengths with reference to FIG.
[0023]
In FIG. 2, the incident energy Eλ from the subject 1 is obtained by scanning the image of the subject 1 horizontally and vertically by the vertical drive mirror 8 and the horizontal drive mirror 9 with respect to the infrared light incident from the window material 18, and by the objective lens 10. An optical passing filtering means (BPF) 4 is disposed on the lighted optical axis.
[0024]
The wavelength band used for the optical BPF 4 is selected according to the type of the subject 1. For example, when a substance such as glass of a building is detected using InSb or the like as a sensor, a BPF of 4.8 to 5.2 μm is used, and the object is a tile, concrete, or the like having a low reflectance and an emissivity. When measuring a high temperature or the like, a wavelength range of 5 to 8 μm is selected.
[0025]
In this example, the optical BPF 4 has a configuration in which two filters 1 and 2 can be switched, and a total of three types of infrared wavelength ranges λ ₁ , λ ₂ without a filter and two types of filters 1 and _{2 are used.} , Λ ₃ can be switched. As a result, three wavelengths can be measured by one device, and the individual difference of the sensor 5 can be eliminated.
[0026]
The infrared energy Eλ that has passed through the optical BPF 4 is incident on a single sensor 5 such as HgcdTe, amplified by a signal amplifier 11, converted to digital data by an analog-to-digital converter (A / D) 12, and then converted to a microcomputer. Based on the emissivity of each substance supplied to the calculating means 14 such as (CPU) and stored in the storage means (memory) 13, a predetermined calculation described later is performed to calculate the true temperature, and the display 16 and the recorder The temperature data is output to 17 for display and printing. Reference numeral 15 denotes an operation unit for inputting an emissivity value or the like to the memory 13 via the PCU 14.
[0027]
In the above-described multicolor infrared imaging apparatus 6, the target substance and the emissivity ελ of the state in three predetermined wavelength ranges are stored in advance in the storage means 13 via the input means 15, and the calculation means is used. The calculation of the true temperature is performed. Hereinafter, the operation of the present invention will be described with reference to FIG.
[0028]
FIG. 3 is a flow chart for performing a true temperature calculation by the calculation means 14 to accurately determine the material and the state of the substance of the subject 1 and to grasp them.
[0029]
In FIG. 3, the first material (A) or measuring the emissivity value epsilon ₁ lambda of the state (or search) to input means 15 of the first step S ₁ a first wavelength range (lambda ₁₎ Writing to the memory 13 via the CPU 14.
[0030]
The second material (B) or measuring the emissivity value epsilon ₂ lambda of the state of the second step _{S 2} first wavelength range (lambda ₁₎ (or search) to through the input means 15 and CPU14 Write to the memory 13.
[0031]
Third third substance (C) or measuring the emissivity value epsilon ₃ lambda of the condition of step _{S 3} the first wavelength range (lambda ₁₎ (or search) to through the input means 15 and CPU14 Write to the memory 13.
[0032]
The first material to third material of the second wavelength range in the fourth step _{S 4} to sixth step _{S 6 (A), (B} ), (C) or emissivity values epsilon ₁ in this state, epsilon _2, epsilon ₃ is measured (or searched) and written into the memory 13 via the input means 15 and the CPU 14.
[0033]
Similarly first material to third material in the third wavelength range in a seventh step _{S 7} to ninth step _{S 9 (A), (B} ), (C) or emissivity values epsilon ₁ in this state, epsilon ₂ , Ε ₃ are measured (or searched) and written into the memory 13 via the input means 15 and the CPU 14.
[0034]
Above the first step _{S 1} to the memory 13 by the ninth step _{S 9} first material A within the range of the first to third wavelength range lambda ₁ to [lambda] _3, the second material B, one third substance C Represents the change state, for example, the emissivities ε ₁ , ε ₂ , and ε _{3 in} the state of water, ice, and the like are stored as follows.
[0035]
ε ₁ (λ ₁ ), ε ₁ (λ ₂ ), ε ₁ (λ ₃ ) {(A) first substance ε ₂ (λ ₁ ), ε ₂ (λ ₂ ), ε ₂ (λ ₃ )} (B) Second substance ε ₃ (λ ₁ ), ε ₃ (λ ₂ ), ε ₃ (λ ₃ ) ‥‥ (C) Third substance
Then the first to third material A of the first to third wavelength range as shown in the tenth step _{S 10,} B, the amount of infrared Eλn = Eλ ₁ of the measurement body 1 made of C, Eλ _2, Eλ ₃ Is measured by sequentially switching the optical BPF 4.
[0037]
From this measurement, Expression 5 is obtained from Expression (1).
[0038]
(Equation 5)
Eλ ₁ = ελ ₁ · f (T ₀ · λ ₁ ) + (1−ελ ₁ ) f (Ta) ‥‥ (7)
Eλ ₂ = ελ ₂ · f (T ₀ · λ ₂ ) + (1−ελ ₂ ) f (Ta) ‥‥ (8)
Eλ ₃ = ελ ₃ · f (T ₀ · λ ₃ ) + (1−ελ ₃ ) f (Ta) ‥‥ (9)
Here, the CPU 14 stores the first substance A or the emissivity value εn = ε ₁ , ε ₂ , ε ₃ } in the state previously stored in the memory 13 as in the eleventh step S ₁₁ (7) to ( subject temperature T ₀ and the background temperature Ta is not yet value numerically by assignment operation to 9).
[0039]
The object temperature _{T 0} and the background temperature Ta when substituting the twelfth step _{S 12} in the first material A or the condition expression (7), to obtain a subtracted from equation (10) (8).
[0040]
Similarly the object temperature T ₀ and the background temperature Ta when substituting first substance A or the condition expression (7), to obtain a subtracted from equation (11) (9).
[0041]
Request In the next 12th step _{S 12} obtained in 11th step _{S 11} (10) and (11) determines the difference between the object temperature _{T 0} of each from the equation [Delta] T ₀ (A).
[0042]
[Delta] T ₀ of the 11 steps _{S 11} and the second material B and third material C or emissivity of the condition the same as the first substance A at a twelfth step _{S 12} described above (B) (B) and By calculating about ΔT ₀ (C), ΔT ₀ (A), ΔT ₀ (B), and ΔT ₀ (C) of the first to third substances A to C are obtained.
[0043]
In a 13 step _{S 13 ΔT 0 (A),} ΔT 0 (B), ΔT 0 (C) value emissivity A (the error) corresponds to the smallest ones, determines B, and either C, these [Delta] T _{0 (a), ΔT 0 (B} ), ΔT 0 (C) is the minimum value of what is fourteenth step _{S 14} to a predetermined material having a predetermined object 1 as shown a, B, are C or its state And it reaches the end.
[0044]
When the material and the state of the subject 1 are determined as described above, when the emissivities in the subject 1 are similar, it is difficult to determine the difference based on the emissivity. However, if the subject has a completely different temperature, the substance or state of the subject can be specified and determined.
[0045]
For example, when the values of ΔT ₀ (A) and ΔT ₀ (C) are substantially the same, the object temperature T ₀ is obtained from Expression 7, and therefore, depending on whether the state temperature of the object 1 exceeds or does not exceed the threshold value, The state may be determined. For example, the threshold may be set to the freezing points of the liquid phase and the solid phase of the substance.
[0046]
As a specific example, assuming that the state of the road surface is the subject 1, a threshold value of 0 ° C. is selected for the wet state of the road (in this case, there is water droplets, equivalent to water) and the frozen state (ice) of the road. It is possible to determine whether the road is in a water droplet state or a frozen state. Of course, also in this case, it is obvious that the emissivity of the road in the dry, water-dropped, or frozen state may be measured, stored in the storage means, and calculated via the CPU, similarly to the above-described configuration.
[0047]
That is, the difference between the dry state and water or ice is determined from the difference in emissivity, and the difference between water and ice is the difference in temperature (T ₀ ). If it is above, it can be determined as a wet state (water). As described above, the present invention is effective not only for the difference in the material of the substance but also for the determination of the state of the road surface.
[0048]
In each of the embodiments described above, the material of the subject or the state of the material is determined by measuring at two wavelengths, and a plurality of wavelengths equal to or more than three wavelengths can be similarly determined.
[0049]
【The invention's effect】
According to the multi-color infrared imaging apparatus of the present invention, it is possible to determine the material and the state of the substance whose emissivity is less than 1 which is less affected by disturbance, and the threshold of the true temperature or the state temperature can be determined even for subjects having different emissivities. Based on this, a substance and its state that can be accurately selected can be obtained.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram for explaining an incident energy obtaining method of the present invention.
FIG. 2 is a block diagram showing one embodiment of a multicolor infrared imaging apparatus according to the present invention.
FIG. 3 is a flowchart for explaining a calculation method of a calculation unit of the multicolor infrared imaging device of the present invention.
FIG. 4 is a block diagram of a conventional infrared imaging device.
[Explanation of symbols]
1 {subject, 4} optical passage filtering means, 5 sensor, 13 storage means (memory) 14 computing means (CPU), 15 input means

Claims (3)

In a multicolor infrared imaging device that measures the radiant energy of a subject and images the subject,
Optical bandpass filtering means for switching a plurality of infrared wavelength ranges from the subject between the subject and the detector of the infrared imaging device and causing the infrared wavelength to be incident on the detector;
Storage means for storing a plurality of substances of the subject within the plurality of wavelength ranges of the infrared ray or emissivity values of the state,
Computing means for measuring the amount of infrared light of the subject within the plurality of infrared wavelength ranges and calculating the subject temperature and the background temperature based on the emissivity values of the plurality of substances or states stored in the storage means. Have
A multicolor infrared imaging apparatus characterized in that a substance or a state of the object is determined from the object temperature obtained by the arithmetic means. 2. The multicolor infrared imaging apparatus according to claim 1, wherein the plurality of infrared wavelength ranges are first to third infrared wavelength ranges. 2. The multi-color infrared imaging apparatus according to claim 1, wherein the plurality of substances of the subject or their states indicate different substances such as concrete or glass or a change state of an object such as water or ice. .

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