JPS6216074B2 - - Google Patents
Info
- Publication number
- JPS6216074B2 JPS6216074B2 JP56010378A JP1037881A JPS6216074B2 JP S6216074 B2 JPS6216074 B2 JP S6216074B2 JP 56010378 A JP56010378 A JP 56010378A JP 1037881 A JP1037881 A JP 1037881A JP S6216074 B2 JPS6216074 B2 JP S6216074B2
- Authority
- JP
- Japan
- Prior art keywords
- infrared
- infrared detector
- monitoring device
- preamplifier
- output
- 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
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/20—Cameras or camera modules comprising electronic image sensors; Control thereof for generating image signals from infrared radiation only
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Closed-Circuit Television Systems (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
- Radiation Pyrometers (AREA)
- Geophysics And Detection Of Objects (AREA)
- Transforming Light Signals Into Electric Signals (AREA)
Description
【発明の詳細な説明】
この発明は、走査の方向と直交する方向に線状
に配置された赤外検出器列（HgCdTe等の半導体
検出器）によつて周囲の情景を熱像として撮像す
る赤外線監視装置に関するものである。[Detailed Description of the Invention] This invention images the surrounding scene as a thermal image using an array of infrared detectors (semiconductor detectors such as HgCdTe) arranged linearly in a direction perpendicular to the scanning direction. This invention relates to an infrared monitoring device.
第１図は、従来の赤外線監視装置の基本的な構
成を表わす図である。受光光学系１と赤外線検出
器列２を保持する架台３は赤外線検出器列２の方
向を軸として駆動源Ｍの作用で回転し、周囲から
入射する入射赤外光４は受光光学系１によつて赤
外線検出器列２上に結像する。したがつて、赤外
線検出器列２中の１個の赤外線検出器は架台３が
回転することによつて、受光光学系１の焦点距離
と赤外線検出器の大きさで決まる縦方向視野の範
囲内の熱像を１本の走査線で走査することにな
る。１個の赤外線検出器出力はテレビジヨンカメ
ラのような通常の撮像装置における走査線１本の
映像信号に対応し、赤外線検出器列２の各検出器
出力を前置増幅器６で増幅した後にマルチプレク
サ５によつて順々に並べれば、テレビジヨンにお
ける映像信号と同様の映像信号が得られ、この信
号を画像表示器７に供給することによつて赤外線
監視装置の周囲の情景の熱像が得られる。ところ
で、第１図に示すような赤外線監視装置の走査方
法において、装置の全周を監視する必要がある場
合には、テレビジヨンカメラ等で行なわれるラス
ター走査におけるような無効走査期間、いわゆる
帰線期間が無くなるために赤外線検出器は常に外
部からの信号光を受光することになる。したがつ
て各検出器に対して設けられた前置増幅器６は本
来の直流信号をも増幅する直流増幅器でなければ
ならない。ところが前流増幅器は交流のみを増幅
する交流増幅器と比べて利得の安定性が悪いこ
と、また、赤外線検出器の出力には１／雑音と
呼ばれる低周波成分を多く持つ雑音が多く含まれ
ること等の理由から前置増幅器６を直流増幅器と
することは実用的ではない。 FIG. 1 is a diagram showing the basic configuration of a conventional infrared monitoring device. The pedestal 3 holding the light-receiving optical system 1 and the infrared detector array 2 is rotated by the action of the drive source M with the direction of the infrared detector array 2 as an axis, and the incident infrared light 4 entering from the surroundings is transmitted to the light-receiving optical system 1. Therefore, an image is formed on the infrared detector array 2. Therefore, one infrared detector in the infrared detector row 2 can be moved within the vertical field of view determined by the focal length of the light receiving optical system 1 and the size of the infrared detector by rotating the mount 3. The thermal image is scanned with one scanning line. The output of one infrared detector corresponds to a video signal of one scanning line in a normal imaging device such as a television camera, and the output of each detector in the infrared detector array 2 is amplified by a preamplifier 6 and then sent to a multiplexer. 5 in sequence, a video signal similar to the video signal in television is obtained, and by supplying this signal to the image display 7, a thermal image of the surrounding scene of the infrared monitoring device can be obtained. It will be done. By the way, in the scanning method of an infrared monitoring device as shown in Fig. 1, when it is necessary to monitor the entire circumference of the device, there is an invalid scanning period, so-called retrace, as in raster scanning performed with a television camera, etc. Since there is no period, the infrared detector always receives signal light from the outside. Therefore, the preamplifier 6 provided for each detector must be a DC amplifier that also amplifies the original DC signal. However, the gain stability of a front-stream amplifier is worse than that of an AC amplifier that only amplifies alternating current, and the output of an infrared detector contains a lot of noise with many low-frequency components called 1/noise. For these reasons, it is not practical to use a DC amplifier as the preamplifier 6.
第２図は前置増幅器を交流増幅器とした従来の
赤外線監視装置における視野及び視野中の目標物
と、前置増幅器出力の例を表わす図である。視野
８の中には高温で小さな目標Ａ９と見かけの温度
が均一で大きな目標Ｂ１０があり、赤外線検出器
列中の別々の赤外線検出器が走査線ａ１１、走査
線ｂ１２でこの視野８を走査し、図に示すように
走査線ａ１１は目標Ａ９と目標Ｂ１０を、走査線
ｂは目標Ａ９のみを走査しているものとする。こ
ような場合には、走査線ａ１１に対応する前置増
幅器出力ａ１３には走査線ｂ１２に対応する前置
増幅器出力ｂ１４とは異なり、目標Ａに対応する
出力１５が含まれる。前置増幅器が交流増幅器で
あれば、その出力の平均値は走査線にかかわらず
全て等しく零となるために目標Ｂに対応する出力
１６と基準レベル１７との差は前置増幅器出力ａ
１３と前置増幅器出力ｂ１４では目標Ｂ１０の見
かけの温度が均一であるにもかかわらず目標Ａに
対応する出力１５に応じて異なる。このような走
査線間のレベルの差は表示画像上において横縞状
のムラとして表わされ、表示画像の画質を著しく
劣化させる原因となる。 FIG. 2 is a diagram showing an example of the field of view, a target in the field of view, and the output of the preamplifier in a conventional infrared monitoring device in which the preamplifier is an AC amplifier. In the field of view 8, there are a small target A9 with a high temperature and a large target B10 with uniform apparent temperature, and separate infrared detectors in the infrared detector array scan this field of view 8 with a scanning line a11 and a scanning line b12. As shown in the figure, it is assumed that the scanning line a11 scans the target A9 and the target B10, and the scanning line b scans only the target A9. In such a case, the preamplifier output a13 corresponding to the scanning line a11 includes the output 15 corresponding to the target A, unlike the preamplifier output b14 corresponding to the scanning line b12. If the preamplifier is an AC amplifier, the average value of its output is equal to zero regardless of the scanning line, so the difference between the output 16 corresponding to target B and the reference level 17 is the preamplifier output a.
13 and the preamplifier output b14 differ depending on the output 15 corresponding to the target A even though the apparent temperature of the target B10 is uniform. Such a difference in level between scanning lines is expressed as horizontal striped unevenness on the displayed image, causing a significant deterioration in the quality of the displayed image.
この発明は、この欠点を除去するために赤外線
監視装置の走査とは同期せずに各赤外線検出器に
基準赤外線光源から赤外光を入射させ、その際の
各前置増幅器出力を同一レベルにクランプする回
路を設けたもので、その内容を図面を用いて詳細
に説明する。 In order to eliminate this drawback, the present invention injects infrared light from a reference infrared light source into each infrared detector without synchronizing with the scanning of the infrared monitoring device, and makes the outputs of each preamplifier at the same level. A clamping circuit is provided, and its contents will be explained in detail using the drawings.
第３図は、この発明の実施例を表わす図であ
る。赤外線検出器列２の前には、架台３の回転と
は同期せずに回転する回転板１８が設けられてお
り、また、前置増幅器６の出力には、回転板１８
の羽根が赤外線検出器列２の視野を遮つたときに
発生するクランプ信号２０によつて入力をクラン
プするクランプ回路２１が各々設けられている。
回転板１８の羽根は赤外線検出器列２の視野を完
全に遮れる範囲内で十分に小さなものとなつてお
り、また、羽根内では温度が均一になるように羽
根を構成する材料は熱伝導の高いものであり、羽
根の表面は赤外線の放射率が高くなるように処理
されていることが望ましい。また、赤外線検出器
列２の視野を回転板１８の羽根が遮る周期Tc
は、前置増幅器６の低域遮断周波数ｆLとの間に
Tc＜１／２πｆＬ ……(1)
の関係があることが望ましい。 FIG. 3 is a diagram showing an embodiment of the invention. In front of the infrared detector array 2, a rotary plate 18 that rotates not in synchronization with the rotation of the pedestal 3 is provided.
A clamp circuit 21 is provided for clamping the input by a clamp signal 20 generated when the blade of the infrared detector blocks the field of view of the infrared detector array 2.
The blades of the rotary plate 18 are small enough to completely block the field of view of the infrared detector array 2, and the material forming the blades is made of heat conductive material so that the temperature is uniform within the blade. It is desirable that the surface of the blade be treated to increase the emissivity of infrared rays. Also, the period Tc during which the blades of the rotary plate 18 block the field of view of the infrared detector row 2
It is desirable that there is a relationship between Tc<1/2πf L (1) and the low cutoff frequency f L of the preamplifier 6.
回転板１８が回転して回転板１８の羽根が赤外
線検出器列２の視野を遮つているときに各検出器
にはこの羽根からの赤外線のみが入射する。羽根
の表面の放射率が高い場合には羽根の表面での反
射が少なく、羽根からの赤外線は羽根の絶対温度
だけで決まる放射成分が支配的となる。一方、羽
根が一様な温度に保たれているならば、羽根の表
面からの放射電力密度は羽根の全面において等し
く、各赤外線検出器の受ける赤外線電力は等しく
なり、したがつて前置増幅器６入力は羽根が赤外
線検出器列の視野を遮る毎に全ての素子について
同一レベルとなる。一方、交流増幅器出力にクラ
ンプ回路を組合わせた回路において、クランプを
行なう周期Tcと、交流増幅器の低域遮断周波数
ｆLとの間に
Tc＜１／２πｆＬ ……(2)
の関係があり、またクランプを行なうタイミング
毎に交流増幅器入力が一定のレベルとなり、か
つ、クランプが常に同一の基準レベルになされる
ならば交流増幅器の低域遮断周波数の高低にかか
わらず交流増幅器入力の直流成分が近似的にクラ
ンプ回路出力へ伝達されることは直流再生の技術
として電子技術者にとつては周知の事実である。
したがつて、クランプ回路２１出力は、前置増幅
器６として交流増幅器を用いているにもかかわら
ず直流成分が保存されたものとなる。 When the rotating plate 18 rotates and the blades of the rotating plate 18 block the field of view of the infrared detector array 2, only infrared rays from the blades enter each detector. When the emissivity of the blade surface is high, there is little reflection on the blade surface, and the infrared radiation from the blade is dominated by a radiation component determined only by the blade's absolute temperature. On the other hand, if the blade is kept at a uniform temperature, the radiation power density from the blade surface is equal across the blade, and the infrared power received by each infrared detector is equal, so the preamplifier 6 The input is at the same level for all elements each time the vane blocks the field of view of the infrared detector array. On the other hand, in a circuit that combines a clamp circuit with an AC amplifier output, there is a relationship between the clamping period Tc and the low cutoff frequency f L of the AC amplifier: Tc < 1/2πf L ...(2) , and if the AC amplifier input is at a constant level every time the clamp is performed, and the clamp is always at the same reference level, the DC component of the AC amplifier input will be constant regardless of the low cutoff frequency of the AC amplifier. It is a well-known fact to electronic engineers as a technique of DC regeneration that the current is approximately transferred to the output of the clamp circuit.
Therefore, in the output of the clamp circuit 21, the DC component is preserved even though an AC amplifier is used as the preamplifier 6.
第４図は、この発明に係る赤外線監視装置にお
ける視野中の目標物を表わす表示画像およびクラ
ンプ回路出力の例を表わす図である。第２図の場
合と同様に、走査線ａ１１は表示画像２２中の高
温で小さな目標Ａ９と見かけの温度が均一で大き
な目標Ｂ１０の両方を、走査線ｂ１２は目標Ｂ１
０のみを走査している。走査線ａ１１に対応する
クランプ回路出力ａ２３と走査線ｂ１２に対応す
るクランプ回路出力ｂ２４はいずれも回転板の羽
根が赤外線検出器列の視野を遮つたときに発生す
るクランプ信号２０によつて基準レベル１７にク
ランプされるために、クランプ回路出力ａ２３に
のみ目標Ａに対する出力１５が含まれているにも
かかわらず、目標Ｂに対応する出力１６と基準レ
ベル１７の差はクランプ回路出力ａ２３とクラン
プ回路出力ｂ２４で等しくなり、温度が均一の目
標はどの走査線においても同一のレベルで表示さ
れ、従来のような横縞状のムラは発生しない。 FIG. 4 is a diagram showing an example of a display image showing a target in the field of view and an output of the clamp circuit in the infrared monitoring device according to the present invention. As in the case of FIG. 2, the scanning line a11 detects both the small, high-temperature target A9 and the large, uniform apparent temperature target B10 in the display image 22, and the scanning line b12 detects the target B1.
Only 0 is scanned. The clamp circuit output a23 corresponding to the scanning line a11 and the clamp circuit output b24 corresponding to the scanning line b12 are both set to the reference level by the clamp signal 20 generated when the blade of the rotating plate blocks the field of view of the infrared detector array. 17, even though only the clamp circuit output a23 includes the output 15 for the target A, the difference between the output 16 corresponding to the target B and the reference level 17 is the difference between the clamp circuit output a23 and the clamp circuit A target whose output b24 is equal and whose temperature is uniform is displayed at the same level in every scanning line, and horizontal stripe-like unevenness as in the conventional case does not occur.
また、表示画像２２中には回転板の羽根が赤外
線検出器列の視野を遮るためにブランキング部分
２６が生じるが、回転板の回転と架台の回転は同
期していないため、架台の回転により、受光光学
系が再び同じ方向を向いたときには視野は遮られ
ず次フイールドのブランキング部分２７は別の場
所に発生する。 In addition, a blanking portion 26 occurs in the displayed image 22 because the blades of the rotary plate block the field of view of the infrared detector array, but since the rotation of the rotary plate and the rotation of the pedestal are not synchronized, the rotation of the pedestal When the light-receiving optical system faces the same direction again, the field of view is not obstructed and the blanking portion 27 of the next field occurs at a different location.
以上のように、この発明に係る赤外線監視装置
では、赤外線検出器列の前面に設けられた複数の
羽根を有する回転板とこの回転板に同期してクラ
ンプを行なうクランプ回路ならびに上記回転板の
回転と非同期に回転する架台によつて、均一性の
高い赤外像が得られる。 As described above, the infrared monitoring device according to the present invention includes a rotary plate having a plurality of blades provided in front of the infrared detector array, a clamp circuit that performs clamping in synchronization with the rotary plate, and a rotating plate that rotates the rotary plate. A highly uniform infrared image can be obtained by using a pedestal that rotates asynchronously.
なお、以上は光検出器として赤外線検出器を用
いた赤外線監視装置について説明したが、この発
明はこれに限らず、可視光の光検出器を用いた光
学監視装置においても応用できる。 Although the above description has been made of an infrared monitoring device that uses an infrared detector as a photodetector, the present invention is not limited to this, and can also be applied to an optical monitoring device that uses a visible light photodetector.
第１図は従来の赤外線監視装置の基本的な構成
を表わす図、第２図は前置増幅器を交流増幅器と
した従来の赤外線監視装置における視野および視
野中の目標物と、前置増幅器出力の例を表わす
図、第３図はこの発明の実施例を表わす図、第４
図はこの発明に係る赤外線監視装置における視野
中の目標を表わす表示画像およびクランプ回路出
力の例を表わす図である。
図中、１は受光光学系、２は赤外線検出器列、
６は前置増幅器、１８は回転板、２０はクランプ
信号、２１はクランパである。なお図中同一ある
いは相当部分には同一符号を付して示してある。
Figure 1 is a diagram showing the basic configuration of a conventional infrared monitoring device, and Figure 2 shows the field of view, a target in the field of view, and the output of the preamplifier in a conventional infrared monitoring device in which the preamplifier is an AC amplifier. FIG. 3 is a diagram showing an embodiment of the present invention; FIG. 4 is a diagram showing an example.
The figure is a diagram showing an example of a display image representing a target in the visual field and an output of a clamp circuit in the infrared monitoring device according to the present invention. In the figure, 1 is a light receiving optical system, 2 is an infrared detector array,
6 is a preamplifier, 18 is a rotating plate, 20 is a clamp signal, and 21 is a clamper. In the drawings, the same or corresponding parts are denoted by the same reference numerals.
Claims (1)
た赤外線検出器及び受光光学系と、赤外線検出器
出力を増幅する交流前置増幅器と、上記赤外線検
出器列と受光光学系の組合せを赤外線検出器列の
方向を軸として回転させることによつて周囲の情
景を走査する架台とを有し、周囲の情景の熱像を
得る赤外線監視装置において、複数の羽根を有す
る回転板を赤外線検出器列の前面に設け、上記回
転板の回転と架台の回転とを非同期にすると共に
上記回転板の羽根が赤外線検出器の視野を遮つた
ときに上記交流前置増幅器の全ての出力を同一の
レベルにクランプするクランプ回路を設けたこと
を特徴とする赤外線監視装置。 ２ 上記回転板の羽根が赤外線検出器の視野を遮
る周期Tcと交流前置増幅器の低域遮断周波数ｆL
との間に Tc＜１／２πｆＬ の関係が成り立つ特許請求の範囲第１項記載の赤
外線監視装置。[Scope of Claims] 1. Infrared detectors and a light receiving optical system arranged linearly in a direction perpendicular to the scanning direction, an AC preamplifier that amplifies the output of the infrared detectors, and the infrared detector row and light receiving system. An infrared monitoring device that scans a surrounding scene by rotating a combination of optical systems about the direction of an infrared detector row as an axis, and obtains a thermal image of the surrounding scene, the infrared monitoring device having a plurality of blades. A rotary plate is provided in front of the infrared detector array, and the rotation of the rotary plate and the rotation of the pedestal are asynchronous, and when the blades of the rotary plate block the field of view of the infrared detector, all of the AC preamplifiers An infrared monitoring device characterized by being provided with a clamp circuit that clamps the outputs of the two to the same level. 2 The period Tc at which the blade of the rotating plate blocks the field of view of the infrared detector and the low cutoff frequency f L of the AC preamplifier
The infrared monitoring device according to claim 1, wherein the relationship Tc<1/2πf L holds true.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56010378A JPS57124981A (en) | 1981-01-27 | 1981-01-27 | Monitor for infrared ray |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56010378A JPS57124981A (en) | 1981-01-27 | 1981-01-27 | Monitor for infrared ray |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57124981A JPS57124981A (en) | 1982-08-04 |
| JPS6216074B2 true JPS6216074B2 (en) | 1987-04-10 |
Family
ID=11748465
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56010378A Granted JPS57124981A (en) | 1981-01-27 | 1981-01-27 | Monitor for infrared ray |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57124981A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1993000576A1 (en) * | 1991-06-24 | 1993-01-07 | Matsushita Electric Industrial Co., Ltd. | Device for sensing thermal image |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2760146B2 (en) * | 1990-11-08 | 1998-05-28 | 松下電器産業株式会社 | Thermal image detector |
| US5528038A (en) * | 1991-05-07 | 1996-06-18 | Matsushita Electric Industrial Co., Ltd. | Temperature distribution measurement apparatus and its application to a human body detecting system |
| JPH0510825A (en) * | 1991-07-05 | 1993-01-19 | Matsushita Electric Ind Co Ltd | Disaster prevention detection device having thermal image detection means |
| JP3010459B2 (en) * | 1992-08-03 | 2000-02-21 | 松下電器産業株式会社 | Temperature distribution measuring device and human body detection system |
| JPH0694539A (en) * | 1992-09-17 | 1994-04-05 | Matsushita Electric Ind Co Ltd | Thermal image detector |
| JPH0694536A (en) * | 1992-09-17 | 1994-04-05 | Matsushita Electric Ind Co Ltd | Thermal image detector |
| JPH0694533A (en) * | 1992-09-17 | 1994-04-05 | Matsushita Electric Ind Co Ltd | Thermal image detector |
| JPH0694531A (en) * | 1992-09-17 | 1994-04-05 | Matsushita Electric Ind Co Ltd | Thermal image detector |
| US5660471A (en) * | 1993-02-26 | 1997-08-26 | Matsushita Electric Industrial Co., Ltd. | Temperature distribution measuring device and measuring method |
| JPH06258137A (en) * | 1993-03-04 | 1994-09-16 | Matsushita Electric Ind Co Ltd | Pyroelectric infrared ray sensor |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS522340U (en) * | 1975-06-24 | 1977-01-08 | ||
| JPS5454689A (en) * | 1977-10-11 | 1979-05-01 | Nec Corp | Pyrovidicon image pickup apparatus |
-
1981
- 1981-01-27 JP JP56010378A patent/JPS57124981A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1993000576A1 (en) * | 1991-06-24 | 1993-01-07 | Matsushita Electric Industrial Co., Ltd. | Device for sensing thermal image |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57124981A (en) | 1982-08-04 |
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