JP2743427B2 - Infrared imaging device - Google Patents
Infrared imaging deviceInfo
- Publication number
- JP2743427B2 JP2743427B2 JP1006294A JP629489A JP2743427B2 JP 2743427 B2 JP2743427 B2 JP 2743427B2 JP 1006294 A JP1006294 A JP 1006294A JP 629489 A JP629489 A JP 629489A JP 2743427 B2 JP2743427 B2 JP 2743427B2
- Authority
- JP
- Japan
- Prior art keywords
- signal
- infrared
- detection
- signal processing
- infrared detection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000003331 infrared imaging Methods 0.000 title claims description 7
- 238000001514 detection method Methods 0.000 claims description 41
- 238000006243 chemical reaction Methods 0.000 claims description 13
- 238000010586 diagram Methods 0.000 description 6
- 238000003384 imaging method Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910052771 Terbium Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 238000003672 processing method Methods 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 229910052715 tantalum Inorganic materials 0.000 description 2
- 229910052774 Proactinium Inorganic materials 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229910052714 tellurium Inorganic materials 0.000 description 1
- PORWMNRCUJJQNO-UHFFFAOYSA-N tellurium atom Chemical compound [Te] PORWMNRCUJJQNO-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Transforming Light Signals Into Electric Signals (AREA)
Description
【発明の詳細な説明】 「産業上の利用分野」 この発明は被写体の温度分布状態を画像表示するのに
用いられる赤外線撮像装置に関し、特にその信号処理方
式に関する。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared imaging apparatus used to display an image of a temperature distribution state of a subject, and particularly to a signal processing method thereof.
「従来の技術」 従来の赤外線撮像装置は、単一の赤外線検出素子を用
いて機械走査方式によるラスタ走査で映像信号を得てい
た。したし近年より一層の高性能化及びテレビジョン並
のリアルタイム性の追求から、50〜150素子を列状に配
列したリニアアレイを用いる方式が実用されはじめてい
る。[Prior Art] A conventional infrared imaging apparatus obtains a video signal by raster scanning by a mechanical scanning method using a single infrared detecting element. However, in recent years, a system using a linear array in which 50 to 150 elements are arranged in a row has begun to be practically used in order to further improve the performance and pursue real-time properties comparable to a television.
第５図はこの種の撮像装置の原理的な構成を示すもの
である。被写体からの光束１は赤外レンズ２を介して水
平走査鏡３に入射する。水平走査鏡３の外形は例えば断
面が正８角形の角柱でその側面が赤外線を反射するミラ
ーとなっており、中心軸Ｙ−Ｙを中心として回転され
る。水平走査鏡３で反射された光束１は、垂直走査鏡４
で反射されて反射鏡５に入射しそこで再び反射されて結
像レンズ６を介して赤外線検出アレイ６に入射する。こ
の例では、同アレイ６が８素子より成る場合を示してお
り、第６図に示すように、画像分解する場合、８本のラ
スターを１纏として水平、垂直走査される。即ち、水平
走査は水平走査鏡３を高速回転させることにより行わ
れ、また垂直走査は垂直走査機構８により垂直走査鏡４
を回転又は上下に振動させることにより行われる。赤外
線検出アレイ７はデュワー９内に収容され、液体窒素に
より−190℃程度に冷却されている。検出アレイ７の各
素子により検出された信号つまり光電変換された信号V
si（ｉ＝１〜８）はそれぞれ信号処理回路101，102，…
108で増幅されて走査変換回路11に並列に入力される。
走査変換回路11では、並列に入力された信号処理回路10
iの出力Vsi′が並直列変換されると共に標準テレビ方
式、例えばNTSC方式のテレビ信号に変換されて出力端子
12に出力される。FIG. 5 shows the principle configuration of this type of imaging apparatus. A light beam 1 from a subject enters a horizontal scanning mirror 3 via an infrared lens 2. The outer shape of the horizontal scanning mirror 3 is, for example, a prism having a regular octagonal cross section and a side surface serving as a mirror that reflects infrared rays, and is rotated about a central axis Y-Y. The light beam 1 reflected by the horizontal scanning mirror 3 is applied to a vertical scanning mirror 4
Then, the light is reflected on the reflecting mirror 5, is reflected again there, and is incident on the infrared detection array 6 via the imaging lens 6. This example shows a case in which the array 6 is composed of eight elements. As shown in FIG. 6, when the image is decomposed, horizontal and vertical scanning is carried out by integrating eight rasters. That is, the horizontal scanning is performed by rotating the horizontal scanning mirror 3 at high speed, and the vertical scanning is performed by the vertical scanning mechanism 8 by the vertical scanning mechanism 8.
By rotating or vibrating up and down. The infrared detection array 7 is housed in a dewar 9 and cooled to about -190 ° C by liquid nitrogen. A signal V detected by each element of the detection array 7, that is, a signal V obtained by photoelectric conversion
si (i = 1 to 8) are signal processing circuits 10 1 , 10 2 ,.
It is amplified by 108 and input in parallel to the scanning conversion circuit 11.
In the scan conversion circuit 11, the signal processing circuit 10
The output V si ′ of i is converted into a parallel television signal and converted into a television signal of a standard television system, for example, an NTSC system.
Output to 12.
ところで、各検出素子の光電変換特性にバラツキがあ
るため、表示画像に一定パターンの感度不均一性が発生
し、画質劣化の要因となるので、各素子の光電変換特性
のバラツキを補正する必要がある。従来の補正方法は、
各素子に温度Ta及びTbの二つの基準赤色源（図示せず）
の光を個別に照射し、各素子の入力光量Pa及びPb（それ
ぞれ基準温度Ta及びTbに対応する）における信号処理回
路10iの出力Vsi′がそれぞれ一致するように（第７図参
照）、同回路において利得及びオフセットを調整するよ
うにしている。By the way, since the photoelectric conversion characteristics of each detection element vary, a uniform non-uniformity of the sensitivity of the display image occurs in the displayed image, which causes deterioration of the image quality. Therefore, it is necessary to correct the variation of the photoelectric conversion characteristics of each element. is there. The conventional correction method is
Two reference red sources of temperature Ta and Tb for each element (not shown)
And the output V si ′ of the signal processing circuit 10 i at the input light amounts Pa and Pb of the respective elements (corresponding to the reference temperatures Ta and Tb, respectively) coincide with each other (see FIG. 7). In this circuit, the gain and the offset are adjusted.
「発明が解決しようとする課題」 赤外線検出アレイの各素子のバラツキを補正する従来
の方法は、各素子の特性が線形であれば完全な補正が可
能である。またたとえ非線形であっても、その特性が２
点で一致させることにより使用領域での特性がほぼ一致
するような特性であれば問題ない。しかし赤外線検出ア
レイの場合はそうはならない。特に最近広く使われはじ
めたMCT検出器（水銀、カドミウム及びテルルを使った
検出器）の場合、各素子の非線形特性のバラツキが大き
く、たとえ限られた範囲で補正できても、入力光量に大
きなレベル差のある画像、或いはレベル変動の大きな画
像に対しては、補正誤差が大きくなり、感度バラツキに
よる画質変化はさけられない。[Problems to be Solved by the Invention] The conventional method of correcting the variation of each element of the infrared detection array can be completely corrected if the characteristic of each element is linear. Even if it is nonlinear, its characteristic is 2
There is no problem as long as the characteristics in the use area are almost the same by matching the points. However, this is not the case with infrared detection arrays. Particularly in the case of MCT detectors (detectors using mercury, cadmium, and tellurium), which have recently become widely used, the non-linear characteristics of each element vary widely. For an image having a level difference or an image having a large level fluctuation, a correction error becomes large, and a change in image quality due to sensitivity variation cannot be avoided.
この発明の目的は、赤外線検出アレイの各素子の特性
バラツキを従来より広い範囲に亘って、より正確に補正
できる新しい信号処理法を提供するにある。SUMMARY OF THE INVENTION It is an object of the present invention to provide a new signal processing method capable of more accurately correcting the characteristic variation of each element of an infrared detection array over a wider range than before.
「課題を解決するための手段」 この発明は、水平走査鏡と、垂直走査鏡と、赤外線検
出アレイと、複数の信号処理回路と、走査変換回路とを
具備する赤外線撮像装置に関するものであって、 上記赤外線検出アレイは、複数の赤外線検出素子を列
状に配列したものであり、 上記信号処理回路は、上記赤外線検出素子毎に設けら
れ、ROMを有し、赤外線検出素子の検出信号をそのROMの
アドレス入力端子に入力して、対応する記憶領域に格納
されているところの、対応する赤外線検出素子の非直線
性を補正した検出信号を出力するものであり、 上記走査変換回路は、上記複数の信号処理回路より並
列に入力される検出信号を並直列変換すると共に、標準
テレビ信号に変換して出力するものである。The present invention relates to an infrared imaging apparatus including a horizontal scanning mirror, a vertical scanning mirror, an infrared detection array, a plurality of signal processing circuits, and a scan conversion circuit. The infrared detection array has a plurality of infrared detection elements arranged in a row, and the signal processing circuit is provided for each of the infrared detection elements, has a ROM, and outputs a detection signal of the infrared detection element. The detection signal is input to an address input terminal of the ROM and outputs a detection signal in which the nonlinearity of the corresponding infrared detection element stored in the corresponding storage area is corrected. In addition to parallel-to-serial conversion of detection signals input in parallel from a plurality of signal processing circuits, the detection signals are converted into standard television signals and output.
「実施例」 この発明の撮像装置には従来と同様に水平走査鏡、垂
直走査鏡などより成る機械光学的な走査機構が用いられ
る。赤外線検出アレイ以降の電子回路、特に信号処理回
路にこの発明の特徴がある。第１図に示すように、赤外
線検出アレイ１の各素子19i（ｉ＝１〜８）の検出出力
はそれぞれ増幅器20で増幅された後、AD変換器21を介し
てディジタル信号に変換される。そのディジタル信号は
ROM（読出し専用メモリ）22のアドレス入力端子に入力
される。"Embodiment" A mechanical optical scanning mechanism including a horizontal scanning mirror, a vertical scanning mirror, and the like is used in the imaging apparatus of the present invention as in the related art. Electronic circuits subsequent to the infrared detection array, particularly signal processing circuits, have the feature of the present invention. As shown in FIG. 1, the detection output of each element 19 i (i = 1 to 8) of the infrared detection array 1 is amplified by an amplifier 20 and then converted into a digital signal via an AD converter 21. . The digital signal is
It is input to an address input terminal of a ROM (read only memory) 22.
各ROM22には前もって対応する赤外線検出素子19iの非
直線性を補正した検出信号VS′が検出信号VSをアドレス
とする記憶領域に格納されている。即ち、検出素子19i
の赤外線に対する光電変換特性が第２図に示すように、
検出信号VSνの点において理想的な直線00′より−δν
だけずれていたとすればROM22のVSνをアドレスとする
記憶領域には、第３図に示すように、VSν′＝VSν＋δ
νが記憶されている。このようにして検出信号VSの所定
のダイナミックレンジにおいて、対応する補正値VS′が
格納されて、所謂参照テーブルが構成される。従って、
各素子に対応する参照テーブルには各素子の特性に応じ
た個有のデータが格納される。ROM22の出力、つまり補
正された検出信号VS′の入力光量Ｐに対する特性は第４
図に示すように理想的な直線となる。このようにして入
力光量Ｐに対する各ROM22の出力は同一の直線特性とな
り、よって各検出素子19iのバラツキが補正される。各R
OM22の出力は並列に走査変換回路11に入力されて、並直
列変換されると共に、標準テレビ方式のテレビ信号（し
かしディジタル信号）に変換されてDA変換器23に出力さ
れ、アナグロのテレビ信号に変換されて出力端子12に出
力される。なお、上記の対応する一組の増幅器20、AD変
換器21及びROM22により信号処理回路10iが構成される。Each ROM22 is stored in the storage area beforehand detection signal V S to the non-linearity has been corrected for the corresponding infrared detection element 19 i 'is an address detection signal V S. That is, the detection element 19 i
As shown in FIG. 2, the photoelectric conversion characteristic of
From the ideal straight line 00 ′ at the point of the detection signal V S ν, −δν
As shown in FIG. 3, in the storage area having the address of V S ν of the ROM 22, V S ν ′ = V S ν + δ
v is stored. In this manner, in a predetermined dynamic range of the detection signal V S , the corresponding correction value V S ′ is stored, and a so-called lookup table is configured. Therefore,
Reference data corresponding to each element stores unique data corresponding to the characteristics of each element. The characteristics of the output of the ROM 22, that is, the corrected detection signal V S ′ with respect to the input light amount P
It becomes an ideal straight line as shown in the figure. The output of each ROM22 with respect to the input light intensity P in this way becomes the same linear characteristics, thus the variation of the detection elements 19 i is corrected. Each R
The output of the OM 22 is input to the scan conversion circuit 11 in parallel, and is converted into a parallel-to-serial signal. The output signal is also converted to a standard television signal (but a digital signal) and output to the DA converter 23. It is converted and output to the output terminal 12. The signal processing circuit 10 i is constituted by a set of amplifier 20, AD converter 21 and ROM22 which the corresponding.
「発明の効果」 この発明によれば、赤外線検出アレイ７の各検出素子
の光電変換特性のバラツキを従来より広い範囲に亘り、
より正確に補正できる。従って、入力光量に大きなレベ
ル差のある画像、或いはレベル変動の大きな画像に対し
ても素子バラツキに起因して画質を劣化させる恐れはな
く、従来より高品位の画像が得られる。[Effects of the Invention] According to the present invention, the variation of the photoelectric conversion characteristics of each detection element of the infrared detection array 7 can be widened as compared with the related art.
More accurate correction can be made. Therefore, even for an image having a large level difference in the input light amount or an image having a large level fluctuation, there is no risk of deteriorating the image quality due to the element variation, and a higher quality image than the conventional image can be obtained.
また、この発明によれば検出素子のバラツキを補正す
るのに、従来のような二つの基準赤色源（基準温度源）
を必要としないので、それだけ装置を経済化できる効果
もある。Further, according to the present invention, two reference red sources (reference temperature sources) as in the prior art are used to correct the variation of the detection elements.
Since there is no need for this, there is an effect that the apparatus can be economically reduced.
第１図はこの発明の実施例の要部のブロック図、第２図
は第１図の赤外線検出アレイ７の１つの検出素子の光電
変換特性を示す図、第３図は第２図の特性をもつ検出素
子と対応する第１図のROM22に格納された参照テーブル
を説明するための図、第４図は第１図の検出素子19
i（ｉ＝１〜８）の入力光量Ｐに対するROM22の出力特性
を示す図、第５図は従来の赤外線撮像装置の原理的構成
を示すブロック図、第６図は第５図において、被写体
（対称とする画像）を機械光学的走査によりラスター８
本分纏めて分解走査する状態を説明するための図、第７
図は第５図の信号処理回路10の出力VS′の特性例を示す
図である。FIG. 1 is a block diagram of a main part of an embodiment of the present invention, FIG. 2 is a diagram showing a photoelectric conversion characteristic of one detecting element of the infrared detecting array 7 of FIG. 1, and FIG. 3 is a characteristic of FIG. FIG. 4 is a diagram for explaining a lookup table stored in the ROM 22 of FIG.
FIG. 5 is a diagram showing an output characteristic of the ROM 22 with respect to an input light amount P of i (i = 1 to 8), FIG. 5 is a block diagram showing a basic configuration of a conventional infrared imaging device, and FIG. The image to be symmetrical) is rasterized by mechanical optical scanning.
FIG. 7 is a diagram for explaining a state of performing the resolution scanning collectively for the book;
The figure shows a characteristic example of the output V S 'of the signal processing circuit 10 of FIG.
Claims (1)
アレイと、複数の信号処理回路と、走査変換回路とを具
備する赤外線撮像装置であって、 上記赤外線検出アレイは、複数の赤外線検出素子を列状
に配列したものであり、 上記信号処理回路は、上記赤外線検出素子毎に設けら
れ、ROMを有し、赤外線検出素子の検出信号をそのROMの
アドレス入力端子に入力して、対応する記憶領域に格納
されているところの、対応する赤外線検出素子の非直線
性を補正した検出信号を出力するものであり、 上記走査変換回路は、上記複数の信号処理回路より並列
に入力される検出信号を並直列変換すると共に、標準テ
レビ信号に変換して出力するものである、 赤外線撮像装置。1. An infrared imaging apparatus comprising a horizontal scanning mirror, a vertical scanning mirror, an infrared detection array, a plurality of signal processing circuits, and a scan conversion circuit, wherein the infrared detection array has a plurality of infrared The detection elements are arranged in a row, and the signal processing circuit is provided for each of the infrared detection elements, has a ROM, and inputs a detection signal of the infrared detection element to an address input terminal of the ROM. It outputs a detection signal in which the nonlinearity of the corresponding infrared detection element stored in the corresponding storage area is corrected, and the scan conversion circuit is input in parallel from the plurality of signal processing circuits. An infrared imaging device that converts the detection signal into a parallel signal and converts the signal into a standard television signal and outputs the signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1006294A JP2743427B2 (en) | 1989-01-13 | 1989-01-13 | Infrared imaging device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1006294A JP2743427B2 (en) | 1989-01-13 | 1989-01-13 | Infrared imaging device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02186779A JPH02186779A (en) | 1990-07-23 |
| JP2743427B2 true JP2743427B2 (en) | 1998-04-22 |
Family
ID=11634358
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1006294A Expired - Fee Related JP2743427B2 (en) | 1989-01-13 | 1989-01-13 | Infrared imaging device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2743427B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2314227B (en) * | 1996-06-14 | 1998-12-23 | Simage Oy | Calibration method and system for imaging devices |
| JP2007174112A (en) * | 2005-12-20 | 2007-07-05 | Sumitomo Electric Ind Ltd | Far-infrared imaging apparatus and output value correction method |
| JP5470997B2 (en) * | 2009-04-15 | 2014-04-16 | パナソニック株式会社 | Microwave heating device |
-
1989
- 1989-01-13 JP JP1006294A patent/JP2743427B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02186779A (en) | 1990-07-23 |
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|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |