EP0050750B1 - Infrared intrusion detector - Google Patents

Infrared intrusion detector Download PDF

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Publication number
EP0050750B1
EP0050750B1 EP81107843A EP81107843A EP0050750B1 EP 0050750 B1 EP0050750 B1 EP 0050750B1 EP 81107843 A EP81107843 A EP 81107843A EP 81107843 A EP81107843 A EP 81107843A EP 0050750 B1 EP0050750 B1 EP 0050750B1
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EP
European Patent Office
Prior art keywords
radiation
intrusion detector
collecting element
infrared
infrared intrusion
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EP81107843A
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German (de)
French (fr)
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EP0050750A1 (en
Inventor
Peter Wägli
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Cerberus AG
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Cerberus AG
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Priority to AT81107843T priority Critical patent/ATE9412T1/en
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    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00—Burglar, theft or intruder alarms
    • G08B13/18—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength
    • G08B13/189—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems
    • G08B13/19—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems using infrared-radiation detection systems
    • G08B13/193—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems using infrared-radiation detection systems using focusing means
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S250/00—Radiant energy
    • Y10S250/01—Passive intrusion detectors

Definitions

  • the invention relates to an infrared intrusion detector with optical bundling means and a sensor arrangement in which the infrared radiation incident from a plurality of separate reception areas is recorded and evaluated for alarm signaling in the event of a predetermined change in the recorded radiation.
  • the infrared radiation emanating from a person in the monitored area is evaluated. If the monitored area is divided into several separate reception areas with dark fields in between, each movement of a person causes a modulation of the infrared radiation received by the sensor element, which can be evaluated by means of a known evaluation circuit to indicate an intruder and to give an alarm signal.
  • an infrared radiation intrusion detector in which reflector surfaces are formed as part of a spherical surface, the selected surface part determines the detectable solid angle.
  • the IR radiation is conducted to a radiation receiver via a radiation conductor bundle composed of a large number of individual radiation-conducting elements (e.g. internally braced waveguide).
  • the combination of the radiation beam onto a sensibly small detector is, however, technically difficult to implement.
  • DE-OS 2 836 462 describes a room surveillance reception device in which the IR radiation falls from a focusing lens through a tube onto a radiation converter arranged in the focal plane. Through a reflective layer arranged on the inside of the tube, radiation from further, sector-shaped areas is thrown onto the transducer by multiple reflection. However, the sensitivity of the monitoring device is greatly reduced for the outside areas because of the curved focus surface of the focusing means.
  • the object of the invention is to avoid the disadvantages of the prior art mentioned and in particular to provide an infrared intrusion detector which, with high sensitivity with a single sensor element and a simple optical arrangement with small dimensions, ensures infrared radiation from a multiplicity of selectable reception areas and capable of recording without interference.
  • the sensor arrangement has an elongated radiation collecting element which is arranged at least approximately in the focus surface of the focusing means, the surface of which is designed to be reflective inwards and which has a plurality of radiation entry openings on its longitudinal side and an infrared sensor element on one of the narrow end faces.
  • a reflector 1 is provided as the focusing means, which can be designed, for example, as a spherical mirror with a center point C.
  • the focus surface F of such a spherical mirror is known to be a concentric sphere with a half radius.
  • An elongated element 2 is arranged in this focus area F, which element serves to collect the infrared radiation focused on the focus area F.
  • This radiation collecting element 2 can be designed, for example, as an air-accessible tube with a mirrored inner surface 3, or as an IR-transparent transparent body, on the surface of which a reflective layer 3 is applied.
  • the cross section of this element can be circular, for example, for reasons of simpler manufacture or adjustability.
  • the axis of this elongated element 2 is curved in accordance with the focus surface F.
  • it can expediently be designed to be flexible. If a correspondingly corrected optic is used as the bundling means, a tube or transparent body with a straight axis can also be used.
  • a sensor element 5 is attached to one of the narrow end faces of the tube brings, the other is mirrored or carries another sensor element.
  • radiation inlet openings 4 are provided on its surface.
  • the collecting element 2 is designed as an air-filled tube, these can be formed as holes in its jacket, when it is designed as a transparent body as interruptions in the reflective coating 3.
  • the radiation that has entered through these radiation inlet openings 4 is reflected many times inside the radiation collecting element 2 on its inner surface 3 and finally arrives at the sensor element 5 attached to one end face, which is connected to an evaluation circuit by means of connecting lines 6. Since the area of the radiation entry openings 4 only makes up a very small part of the entire inner surface of the radiation collecting element 2, practically all of the radiation that has entered the inside of the collecting element 2 reaches the sensor element 5 without any significant losses.
  • the radiation entry openings 4 mentioned are now located precisely at the points where the radiation arriving from certain desired reception areas is focused by the reflector 1.
  • Each radiation entry opening 4 is assigned a specific radiation reception area, the opening angle of which depends on the dimensions of the radiation entry opening 4 and the quality of the image.
  • the radiation inlet openings 4 can be provided on the surface of the radiation collecting element 2.
  • the arrangement can thus be easily adapted to the desired conditions of use.
  • a particularly simple optic is completely sufficient, and only a single sensor element is required, which can be connected to a correspondingly simple and fault-prone evaluation circuit.
  • no segment optics are required, but only a single reflector, optimal sensitivity can be achieved.
  • the bundling means designed as a spherical mirror used in the example described can also be designed in a different way.
  • a parabolic mirror can be used that provides a better image, at least in the vicinity of the axis, or refractive optics can be used that can be easily corrected so that the focus surface is not very curved, i.e. is almost flat, so that the radiation collecting element 2 can have a cylindrical shape with a straight axis.
  • Fig. 2 shows an embodiment with a collecting lens 10 as a focusing means.
  • the radiation collecting element 2 is configured analogously to the previous example and is arranged in the focus area F of the collecting lens 10.
  • Each of the radiation entry openings 4 corresponds to a separate reception direction or reception area A " A2 ... As.
  • FIG. 3 shows an infrared intrusion detector with a housing 9, the front side of which is taken up by a bundling means 11, which is designed as a central section of a Fresnel step lens.
  • a bundling means 11 which is designed as a central section of a Fresnel step lens.
  • a tubular radiation collecting element 2 with different openings 4 facing the Fresnel lens 11 is again provided.
  • an end face of the tube is provided Arranged infrared sensor element 5, which is connected to an integrated circuit 7, which can be designed, for example, according to US 4 179 691 or US 4 166 955.
  • Each opening 4 in turn corresponds to a radiation reception area, and this evaluation circuit 7 emits a signal via signal lines 8 as soon as the infrared radiation picked up by the sensor element 5 changes in a manner characteristic of the movement of an intruder through the radiation receiving areas.
  • one or more prisms can be provided in front of or behind parts of the converging lens, through which the individual reception beams can each be split into a plurality of beams.
  • the number of radiation receiving areas can be multiplied if a certain intensity weakening of the individual areas can be accepted.
  • a prism 12 can be arranged in front of the lower half of the Fresnel lens 11. This has the effect that the radiation impinging on the lower half is deflected by a certain angle, while the radiation impinging on the upper half remains unaffected.
  • Each reception area is therefore split into two separate areas.
  • the upper half of the lens focuses radiation from direction A 31 onto the central opening 4, the lower half from the direction A 32 inclined toward it.
  • an infrared intrusion detector can be created in a single way, the reception areas of which are in the form of two radiation curtains to be passed in succession.
  • the prism element can also be combined with and integrated into the collecting lens by being designed as a multi-zone lens with zones of different optical axes.
  • one half of the Fresnel lens 11 can have the shape of a wedge 13 on its front or rear side, which replaces the prism 12 and exhibits the same optical effect.
  • Such an optical element is particularly easy to manufacture and requires no special adjustment.
  • the infrared intrusion detector shown has optimum sensitivity and, moreover, has a particularly simple and interference-free construction. It is particularly suitable for applications where an infrared protective curtain with closely spaced reception areas is desired.
  • the intrusion detector according to FIG. 3 can be further developed in that the radiation-collecting tube 2 is arranged to rotate uniformly about its axis which has just been formed. The openings are then not fixed on an axially parallel straight line, but are provided at different angles of rotation on the pipe surface, for example on a helix. During the rotation of the tube 2, the individual openings 14 then come successively into the focus area, i.e. they receive radiation from the assigned reception area at different times. This enables the different reception areas to be scanned over time.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Burglar Alarm Systems (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Geophysics And Detection Of Objects (AREA)

Abstract

An infrared intrusion detector wherein a plurality of separate radiation receiving regions or fields of view are focused by a single focusing optic, for instance a reflector or a Fresnel lens upon a single sensor element through an elongate or lengthwise extending radiation collecting element. The radiation collecting element can be constituted by an internally metal coated tube or a transparent body having a reflecting surface layer or coating, wherein the reflection coating is interrupted by radiation inlet openings. The infrared radiation which is focused by the focusing optic enters through such openings into the interior of the radiation collecting element and arrives, after having been reflected a number of times, at the sensor element which is mounted at an end side thereof.

Description

Die Erfindung betrifft einen Infrarot-Einbruchdetektor mit optischen Bündelungsmitteln und einer Sensoranordnung, bei dem die aus mehreren getrennten Empfangsbereichen einfallende Infrarot- Strahlung aufgenommen und zur Alarmsignalgabe bei einer vorbestimmten Änderung der aufgenommenen Strahlung ausgewertet wird.The invention relates to an infrared intrusion detector with optical bundling means and a sensor arrangement in which the infrared radiation incident from a plurality of separate reception areas is recorded and evaluated for alarm signaling in the event of a predetermined change in the recorded radiation.

Bei solchen Einbruchdetektoren wird die von einer Person im überwachten Bereich ausgehende Infrarot-Strahlung ausgewertet. Wenn der überwachte Bereich in mehrere getrennte Empfangsbereiche mit dazwischenliegenden Dunkelfeldern aufgeteilt ist, so bewirkt jede Bewegung einer Person eine Modulation der vom Sensorelement empfangenen Infrarot- Strahlung, welche mittels einer bekannten Auswerteschaltung zur Anzeige eines Eindringlings und zur Alarmsignalgabe ausgewertet werden kann.In the case of such intrusion detectors, the infrared radiation emanating from a person in the monitored area is evaluated. If the monitored area is divided into several separate reception areas with dark fields in between, each movement of a person causes a modulation of the infrared radiation received by the sensor element, which can be evaluated by means of a known evaluation circuit to indicate an intruder and to give an alarm signal.

Zur Schaffung der erforderlichen getrennten Empfangsbereiche sind verschiedene optische Anordnungen bekannt. Eine besonders gute Empfindlichkeit lässt sich erreichen, wenn aus allen Empfangsbereichen eine möglichst grosse Strahlungsmenge aufgenommen und ausgewertet wird. Aus US 3 760 399, US 3 829 693 oder US 3 958 118 vorbekannte Einbruchdetektoren verwenden dazu einen für alle Empfangsbereiche gemeinsamen Reflektor, der die aus diesen Empfangsbereichen einfallende Strahlung auf mehrere nebeneinander angeordnete Sensorelemente bündelt. Da eine Vielzahl solcher Sensorelemente verwendet wird, ist jedoch eine komplizierte und störanfällige Auswerteschaltung erforderlich, an welche diese Vielzahl von Sensorelementen angeschlossen ist. Zudem ist die Zahl der möglichen Sensorelemente und damit die Anzahl und Auswahl der Empfangsbereiche stark eingeschränkt.Various optical arrangements are known for creating the necessary separate reception areas. A particularly good sensitivity can be achieved if the largest possible amount of radiation is recorded and evaluated from all reception areas. For this purpose, intrusion detectors previously known from US Pat. No. 3,760,399, US Pat. No. 3,829,693 or US Pat. No. 3,958,118 use a reflector which is common to all reception areas and which bundles the radiation incident from these reception areas onto a plurality of sensor elements arranged next to one another. Since a large number of such sensor elements is used, however, a complicated and fault-prone evaluation circuit is required, to which this large number of sensor elements is connected. In addition, the number of possible sensor elements and thus the number and selection of the reception areas is severely restricted.

Aus anderen Vorpublikationen, beispielsweise US 3 703 718; US 4 058 726 und US 4 081 680 ist es zwar bekannt, diesen Nachteil dadurch zu vermeiden, dass eine Vielzahl von Reflektoren vorgesehen wird, welche jeweils Strahlung aus einem Empfangsbereich auf ein gemeinsames Sensorelement fokussieren. Hierbei muss jedoch der Nachteil in Kauf genommen werden, dass aus jedem Empfangsbereich nur eine geringe Strahlungsmenge aufgenommen wird und die Empfindlichkeit daher vermindert ist oder die Zahl der Empfangsbereiche beschränkt werden muss.From other previous publications, for example US 3,703,718; US 4,058,726 and US 4,081,680 disclose to avoid this disadvantage by providing a plurality of reflectors, each of which focuses radiation from a reception area onto a common sensor element. Here, however, the disadvantage must be accepted that only a small amount of radiation is absorbed from each reception area and the sensitivity is therefore reduced or the number of reception areas has to be limited.

Aus der DE-OS 2 719 191 ist ein Infrarotstrahlungseinbruchdetektor bekannt, bei dem Reflektorflächen als Teil einer Kugeloberfläche ausgebildet sind, der gewählte Oberflächenteil bestimmt den erfassbaren Raumwinkel. Die IR-Strahlung wird über ein aus einer Vielzahl einzelner strahlungsleitender Elemente (z.B. innenversp. Hohlleiter) zusammengesetztes Strahlungsleiterbündel auf einen Strahlungsempfänger geleitet. Die Zusammenfassung des Strahlungsbündels auf einen sinnvollerweise kleinen Detektor ist jedoch technisch schwierig zu realisieren.From DE-OS 2 719 191 an infrared radiation intrusion detector is known, in which reflector surfaces are formed as part of a spherical surface, the selected surface part determines the detectable solid angle. The IR radiation is conducted to a radiation receiver via a radiation conductor bundle composed of a large number of individual radiation-conducting elements (e.g. internally braced waveguide). The combination of the radiation beam onto a sensibly small detector is, however, technically difficult to implement.

In der DE-OS 2 836 462 ist eine Raumüberwachungs-Empfangseinrichtung beschrieben, bei der die IR-Strahlung von einer Fokussierlinse durch ein Rohr auf einen in der Brennebene angeordneten Strahlungswandler fällt. Durch eine an der Innenseite des Rohres angeordnete Reflexschicht wird durch Mehrfachreflexion Strahlung aus weiteren, sektorförmigen Bereichen auf den Wandler geworfen. Die Empfindlichkeit der Überwachungseinrichtung ist für die Aussenbereiche wegen der gekrümmten Fokusfläche des Fokussiermittels jedoch stark reduziert.DE-OS 2 836 462 describes a room surveillance reception device in which the IR radiation falls from a focusing lens through a tube onto a radiation converter arranged in the focal plane. Through a reflective layer arranged on the inside of the tube, radiation from further, sector-shaped areas is thrown onto the transducer by multiple reflection. However, the sensitivity of the monitoring device is greatly reduced for the outside areas because of the curved focus surface of the focusing means.

Aufgabe der Erfindung ist es, die erwähnten Nachteile des Standes der Technik zu vermeiden und insbesondere einen Infrarot-Einbruchdetektor zu schaffen, der bei hoher Empfindlichkeit mit einem einzigen Sensorelement und einer einfachen optischen Anordnung bei kleinen Abmessungen Infrarot- Strahlung aus einer Vielzahl beliebig wählbarer Empfangsbereiche sicher und störungsunanfällig aufzunehmen vermag.The object of the invention is to avoid the disadvantages of the prior art mentioned and in particular to provide an infrared intrusion detector which, with high sensitivity with a single sensor element and a simple optical arrangement with small dimensions, ensures infrared radiation from a multiplicity of selectable reception areas and capable of recording without interference.

Erfindungsgemäss wird diese Aufgabe dadurch gelöst, dass die Sensoranordnung ein wenigstens angenähert in der Fokus-Fläche der Bündelungsmittel angeordnetes langgestrecktes Strahlungssammelelement aufweist, dessen Oberfläche nach innen reflektierend ausgebildet ist und welches an seiner Längsseite mehrere Strahlungseintrittsöffnungen und an einer der schmalen Stirnseiten ein InfrarotSensorelement aufweist.According to the invention, this object is achieved in that the sensor arrangement has an elongated radiation collecting element which is arranged at least approximately in the focus surface of the focusing means, the surface of which is designed to be reflective inwards and which has a plurality of radiation entry openings on its longitudinal side and an infrared sensor element on one of the narrow end faces.

Die Erfindung wird anhand der in den Figuren dargestellten Ausführungsbeispiele beschrieben.

  • Fig. 1 a zeigt die optische Anordnung für einen Einbruchdetektor mit Reflektor in Aufsicht.
  • Fig. 1 b zeigt diese Anordnung im Schnitt.
  • Fig. 2 zeigt eine zweite optische Anordnung mit Sammel-Linse.
  • Fig.3 zeigt einen Infrarot-Einbruchdetektor mit Fresnel-Linse.
The invention is described on the basis of the exemplary embodiments shown in the figures.
  • Fig. 1 a shows the optical arrangement for a burglar detector with reflector in supervision.
  • Fig. 1 b shows this arrangement in section.
  • 2 shows a second optical arrangement with a collecting lens.
  • 3 shows an infrared intrusion detector with a Fresnel lens.

Die Fig. 1 a und 1 b zeigen eine optische Anordnung für einen Infrarot-Einbruchdetektor in Aufsicht und im Querschnitt. Als Bündelungsmittel ist dabei ein Reflektor 1 vorgesehen, der beispielsweise als Kugelspiegel mit einem Mittelpunkt C ausgebildet sein kann. Die Fokus-Fläche F eines solchen Kugelspiegels ist bekanntlich eine dazu konzentrische Kugel mit halbem Radius. In dieser Fokus-Fläche F ist ein langgestrecktes Element 2 anngeordnet, welches zur Sammlung der auf die Fokus-Fläche F gebündelten Infrarot-Strahlung dient. Dieses Strahlungssammelelement 2 kann beispielsweise als luftzugängliches Rohr mit verspiegelter Innenfläche 3 ausgebildet sein, oder als IR-strahlungsdurchlässiger Transparentkörper, auf dessen Oberfläche eine reflektierende Schicht 3 aufgebracht ist. Der Querschnitt dieses Elements kann beispielsweise aus Gründen der einfacheren Herstellung oder Justierbarkeit kreisförmig ausgebildet sein. Die Achse dieses langgestreckten Elements 2 ist entsprechend der Fokus-Fläche F gekrümmt. Um das Strahlungssammelelement 2 auf einfache Weise im Einbruchdetektor montieren zu können, kann es zweckmässigerweise biegsam ausgebildet sein. Bei Verwendung einer entsprechend korrigierten Optik als Bündelungsmittel kann jedoch auch ein Rohr oder Transparentkörper mit gerader Achse Verwendung finden. An einer der schmalen Stirnseiten des Rohres ist ein Sensorelement 5 angebracht, die andere istverspiegelt oderträgt ein weiteres Sensorelement.1 a and 1 b show an optical arrangement for an infrared intrusion detector in top view and in cross section. A reflector 1 is provided as the focusing means, which can be designed, for example, as a spherical mirror with a center point C. The focus surface F of such a spherical mirror is known to be a concentric sphere with a half radius. An elongated element 2 is arranged in this focus area F, which element serves to collect the infrared radiation focused on the focus area F. This radiation collecting element 2 can be designed, for example, as an air-accessible tube with a mirrored inner surface 3, or as an IR-transparent transparent body, on the surface of which a reflective layer 3 is applied. The cross section of this element can be circular, for example, for reasons of simpler manufacture or adjustability. The axis of this elongated element 2 is curved in accordance with the focus surface F. In order to be able to easily mount the radiation collecting element 2 in the intrusion detector, it can expediently be designed to be flexible. If a correspondingly corrected optic is used as the bundling means, a tube or transparent body with a straight axis can also be used. A sensor element 5 is attached to one of the narrow end faces of the tube brings, the other is mirrored or carries another sensor element.

Um die vom Reflektor 1 auf die Oberfläche des Strahlungssammelelements 2 fokussierte Strahlung in das Element eintreten zu lassen, sind auf dessen Oberfläche Strahlungseintrittsöffnungen 4 vorgesehen. Diese können bei der Ausführung des Sammelelements 2 als luftgefülltes Rohr als Löcher in dessen Mantel ausgebildet sein, bei der Ausführung als Transparentkörper als Unterbrechungen im reflektierenden Belag 3. Die durch diese Strahlungseintrittsöffnungen 4 eingetretene Strahlung wird im Inneren des Strahlungssammelelements 2 an dessen Innenfläche 3 vielfach reflektiert und gelangt schliesslich auf das an einer Stirnseite angebrachte Sensorelement 5, das mit Anschlussleitungen 6 an eine Auswerteschaltung angeschlossen ist. Da die Fläche der Strahlungseintrittsöffnungen 4 nur einen sehr geringen Teil der gesamten Innenoberfläche des Strahlungssammelelements 2 ausmacht, so erreicht dabei praktisch die gesamte in das Innere des Sammelelements 2 eingetretene Strahlung das Sensorelement 5, ohne nennenswerte Verluste. Die genannten Strahlungseintrittsöffnungen 4 sind nun gerade an den Stellen angebracht, wo die aus bestimmten gewünschten Empfangsbereichen eintreffende Strahlung durch den Reflektor 1 fokussiert wird. Jeder Strahlungseintrittsöffnung 4 ist dabei ein bestimmter Strahlungsempfangsbereich zugeordnet, dessen Öffnungswinkel von den Abmessungen der Strahlungseintrittsöffnung 4, und der Güte der Abbildung abhängt. Die Strahlungseintrittsöffnungen 4 können je nach gewünschtem Muster von Empfangsbereichen entsprechend auf der Oberfläche des Strahlungssammelelements 2 vorgesehen sein.In order to allow the radiation focused by the reflector 1 onto the surface of the radiation collecting element 2 to enter the element, radiation inlet openings 4 are provided on its surface. When the collecting element 2 is designed as an air-filled tube, these can be formed as holes in its jacket, when it is designed as a transparent body as interruptions in the reflective coating 3. The radiation that has entered through these radiation inlet openings 4 is reflected many times inside the radiation collecting element 2 on its inner surface 3 and finally arrives at the sensor element 5 attached to one end face, which is connected to an evaluation circuit by means of connecting lines 6. Since the area of the radiation entry openings 4 only makes up a very small part of the entire inner surface of the radiation collecting element 2, practically all of the radiation that has entered the inside of the collecting element 2 reaches the sensor element 5 without any significant losses. The radiation entry openings 4 mentioned are now located precisely at the points where the radiation arriving from certain desired reception areas is focused by the reflector 1. Each radiation entry opening 4 is assigned a specific radiation reception area, the opening angle of which depends on the dimensions of the radiation entry opening 4 and the quality of the image. Depending on the desired pattern of reception areas, the radiation inlet openings 4 can be provided on the surface of the radiation collecting element 2.

Die Anordnung kann also auf einfache Weise an die gewünschten Verwendungsbedingungen angepasst werden. Dabei ist eine besonders einfache Optik völlig ausreichend, und es ist nur ein einziges Sensorelement erforderlich, welches an eine entsprechend einfache und störunanfällige Auswerteschaltung angeschlossen werden kann. Da zudem keine Segmentoptik erforderlich ist, sondern nur ein einziger Reflektor, so kann eine optimale Empfindlichkeit erreicht werden.The arrangement can thus be easily adapted to the desired conditions of use. A particularly simple optic is completely sufficient, and only a single sensor element is required, which can be connected to a correspondingly simple and fault-prone evaluation circuit. In addition, since no segment optics are required, but only a single reflector, optimal sensitivity can be achieved.

Die in dem beschriebenen Beispiel verwendeten, als Kugelspiegel ausgebildeten Bündelungsmittel können auch in anderer Weise ausgeführt sein. Beispielsweise kann ein Parabolspiegel verwendet werden, der zumindest in der Nähe der Achse eine bessere Abbildung liefert, oder es kann eine Refraktions-Optik Verwendung finden, die leicht so korrigiert werden kann, dass die Fokus-Fläche wenig gekrümmt, d.h. fast eben ist, so dass das Strahlungssammelelement 2 Zylinderform mit gerader Achse besitzen kann.The bundling means designed as a spherical mirror used in the example described can also be designed in a different way. For example, a parabolic mirror can be used that provides a better image, at least in the vicinity of the axis, or refractive optics can be used that can be easily corrected so that the focus surface is not very curved, i.e. is almost flat, so that the radiation collecting element 2 can have a cylindrical shape with a straight axis.

Fig. 2 zeigt ein Ausführungsbeispiel mit einer Sammel-Linse 10 als Bündelungsmittel. Das Strahlungssammelelement 2 ist analog wie beim vorhergehenden Beispiel ausgebildet und in der Fokus-Fläche F der Sammel-Linse 10 angeordnet. Jeder der Strahlungseintrittsöffnungen 4 entspricht eine getrennte Empfangsrichtung oder Empfangsbereich A" A2 ... As.Fig. 2 shows an embodiment with a collecting lens 10 as a focusing means. The radiation collecting element 2 is configured analogously to the previous example and is arranged in the focus area F of the collecting lens 10. Each of the radiation entry openings 4 corresponds to a separate reception direction or reception area A " A2 ... As.

Fig. 3 zeigt einen Infrarot-Einbruchdetektor mit einem Gehäuse 9, dessen Frontseite von einem Bündelungsmittel 11 eingenommen wird, das als zentraler Abschnitt einer Fresnel-Stufenlinse ausgebildet ist. An der Rückseite 9", deren Abstand von der Frontseite 9' der Brennweite f der Fresnel-Linse 11 entspricht, ist wiederum ein rohrförmiges Strahlungssammelelement 2 mit verschiedenen, der Fresnel-Linse 11 zugekehrten Öffnungen 4 vorgesehen. An einer Stirnseite des Rohres ist wiederum ein Infrarotsensorelement 5 angeordnet, das mit einer integrierten Schaltung 7 verbunden ist, welche beispielsweise gemäss US 4 179 691 oder US 4 166 955 ausgebildet sein kann. Jeder Öffnung 4 entspricht wiederum ein Strahlungsempfangsbereich, und diese Auswerteschaltung 7 gibt über Signalleitungen 8 ein Signal ab, sobald sich die vom Sensorelement 5 aufgenommene Infrarot-Strahlung in einer für die Bewegung eines Eindringlings durchdie Strahlungsempfangsbereiche charakteristischen Weise ändert.FIG. 3 shows an infrared intrusion detector with a housing 9, the front side of which is taken up by a bundling means 11, which is designed as a central section of a Fresnel step lens. On the rear side 9 ″, the distance from the front side 9 ′ of which corresponds to the focal length f of the Fresnel lens 11, a tubular radiation collecting element 2 with different openings 4 facing the Fresnel lens 11 is again provided. In turn, an end face of the tube is provided Arranged infrared sensor element 5, which is connected to an integrated circuit 7, which can be designed, for example, according to US 4 179 691 or US 4 166 955. Each opening 4 in turn corresponds to a radiation reception area, and this evaluation circuit 7 emits a signal via signal lines 8 as soon as the infrared radiation picked up by the sensor element 5 changes in a manner characteristic of the movement of an intruder through the radiation receiving areas.

In einer vorteilhaften Weiterbildung der Erfindung können vor oder hinter Teilen der Sammellinse ein oder mehrere Prismen vorgesehen sein, durch die die einzelnen Empfangsstrahlen jeweils in mehrere Strahlen aufgespalten werden können. Dadurch kann die Anzahl der Strahlungsempfangsbereiche vervielfacht werden, falls eine gewisse Intensitätsschwächung der einzelnen Bereiche in Kauf genommen werden kann.In an advantageous development of the invention, one or more prisms can be provided in front of or behind parts of the converging lens, through which the individual reception beams can each be split into a plurality of beams. As a result, the number of radiation receiving areas can be multiplied if a certain intensity weakening of the individual areas can be accepted.

Bei dem in Fig. 3 dargestellten Infrarot-Einbruchdetektor kann beispielsweise vor der unteren Hälfte der Fresnel-Linse 11 ein Prisma 12 angeordnet sein. Dieses bewirkt, dass die auf die untere Hälfte auftreffende Strahlung um einen bestimmten Winkel abgelenkt wird, während die auf die obere Hälfte auftreffende Strahlung unbeeinflusst bleibt. Jeder Empfangsbereich wird daher in zwei getrennte Bereiche aufgespalten. Beispielsweise fokussiert die obere Linsen-Hälfte Strahlung aus Richtung A31 auf die mittlere Öffnung 4, die untere Hälfte aus der dazu geneigten Richtung A32. Bei einer Vielzahl von Öffnungen lässt sich so auf einzelne Weise ein Infrarot-Einbruchdetektor schaffen, dessen Empfangsbereiche die Form zweier nacheinander zu passierender Strahlungsvorhänge haben.In the infrared intrusion detector shown in FIG. 3, for example, a prism 12 can be arranged in front of the lower half of the Fresnel lens 11. This has the effect that the radiation impinging on the lower half is deflected by a certain angle, while the radiation impinging on the upper half remains unaffected. Each reception area is therefore split into two separate areas. For example, the upper half of the lens focuses radiation from direction A 31 onto the central opening 4, the lower half from the direction A 32 inclined toward it. With a large number of openings, an infrared intrusion detector can be created in a single way, the reception areas of which are in the form of two radiation curtains to be passed in succession.

Das Prismen-Element kann auch mit der Sammel- linse vereint und in diese integriert sein, indem sie als Mehr-Zonen-Linse mit Zonen unterschiedlicher optischer Achse ausgeführt ist. In Fig. 3 kann beispielsweise eine Hälfte der Fresnel-Linse 11 auf ihrer Vorder- oder Rückseite die Form eines Keiles 13 aufweisen, der das Prisma 12 ersetzt und die gleiche optische Wirkung zeigt. Ein solches optisches Element ist besonders einfach herstellbar und erfordert keine spezielle Justierung.The prism element can also be combined with and integrated into the collecting lens by being designed as a multi-zone lens with zones of different optical axes. In FIG. 3, for example, one half of the Fresnel lens 11 can have the shape of a wedge 13 on its front or rear side, which replaces the prism 12 and exhibits the same optical effect. Such an optical element is particularly easy to manufacture and requires no special adjustment.

Der dargestellte Infrarot-Einbruchdetektor besitzt trotz seiner flachen unauffälligen Form und seiner kleinen Abmessungen eine optimale Empfindlichkeit und weist zudem eine besonders einfache und störunanfällige Konstruktion auf. Er eignet sich besonders für Verwendungen wo ein Infrarot-Schutzvorhang mit eng nebeneinander in einer Ebene liegenden Empfangsbereichen erwünscht ist. Um den Detektor optimal zum Nachweis von Personen auszubilden, ist es dabei zweckmässig, die Fresnel-Linse aus einem Material auszubilden, das vorzugsweise im Spektralbereich der Körperstrahlung im fernen Infrarot durchlässig ist und als Sensorelement ebenfalls ein vorzugsweise im Infrarot empfindliches Element zu verwenden, beispielsweise ein pyroelektrisches Element, vom Lithium-, Tantalat-, Polyvinyldifluorid-oder Blei-Zirkonat-Titanat-Typ.Despite its flat, inconspicuous shape and its small dimensions, the infrared intrusion detector shown has optimum sensitivity and, moreover, has a particularly simple and interference-free construction. It is particularly suitable for applications where an infrared protective curtain with closely spaced reception areas is desired. In order to optimally design the detector to detect people, it is expedient to remove the Fresnel lens from one Form material that is preferably transparent in the spectral range of body radiation in the far infrared and also use a preferably infrared-sensitive element as the sensor element, for example a pyroelectric element, of the lithium, tantalate, polyvinyl difluoride or lead-zirconate-titanate type.

Der Einbruchdetektor nach Fig. 3 lässt sich noch dadurch weiterbilden, dass das strahlungssammelnde Rohr 2 gleichmässig um seine gerade ausgebildete Achse rotierend angeordnet ist. Die Öffnungen liegen dann nicht fest auf einer achsparallelen Geraden, sondern sind bei verschiedenen Drehwinkeln auf der Rohroberfläche vorgesehen, beispielsweise auf einer Schraubenlinie. Bei der Rotation des Rohres 2 geraten die einzelnen Öffnungenn 14 dann nacheinander in die Fokus-Fläche, d.h. sie erhalten zu verschiedenen Zeiten Strahlung aus dem zugeordneten Empfangsbereich. Dieser ermöglicht es, die verschiedenen Empfangsbereiche zeitlich gestaffelt abzutasten.The intrusion detector according to FIG. 3 can be further developed in that the radiation-collecting tube 2 is arranged to rotate uniformly about its axis which has just been formed. The openings are then not fixed on an axially parallel straight line, but are provided at different angles of rotation on the pipe surface, for example on a helix. During the rotation of the tube 2, the individual openings 14 then come successively into the focus area, i.e. they receive radiation from the assigned reception area at different times. This enables the different reception areas to be scanned over time.

Claims (12)

1. An infrared intrusion detector comprising optical focusing means; a sensor arrangement for taking- up the infrared radiation received from a number of separate receiving regions in order to enable evaluation of the received radiation upon there occuring a predetermined change thereof for purposes of giving an alarm signal, characterized in that said sensor arrangement comprising a substantially lengthwise extending radiation collecting element (2) arranged at least approximately at the focusing surface (F) of the focusing means (1,10,11), said lengthwise extending radiation collecting element (2) having surface means (3) structured so as to be inwardly reflective; said lengthwise extending radiation collecting element (2) having a lengthwise extending side and a small face end; said lengthwise extending side containing a plurality of radiation inlet openings (4) and an infrared sensor element (5) provided for said small face end of said radiation collecting element (2).
2. The infrared intrusion detector as defined in claim 1, characterized in that said radiation collecting element (2) possesses a substantially circular- shaped cross-sectional configuration.
3. The infrared intrusion detector as defined in claim 1 or 2, characterized in that said radiation collecting element (2) is constructed as an air-filled tube which is internally coated; and said tube having an outer surface containing said radiation inlet openings (4).
4. The infrared intrusion detector as defined in claim 1 or 2, characterized in that said radiation collecting element (2) is structured as a transparent body (2) having a surface (3); a reflective coating provided for said surface (3); and said reflective coating being interrupted at a number of locations (4) so as to define said radiation inlet openings (4).
5. The infrared intrusion detector as defined in any of claims 1 to 4, characterized in that said focusing means is structured as a reflector (1).
6. The infrared intrusion detector as defined in claim 5, characterized in that said reflector (1) is structured as a spherical mirror; and that said radiation collecting element (2) being arranged at the site of a sphere arranged substantially concentrically with respect to said spherical mirror (1) and having a radius which is approximately one-half the size of the radius of said spherical mirror (1).
7. The infrared intrusion detector as defined in any of claims 1 to 4, characterized in that said focusing means is structured as a collecting lens (10).
8. The infrared intrusion detector as defined in claim 7, characterized in that said collecting lens is a Fresnel lens (11). ).
9. The infrared intrusion detector as defined in claim 8, characterized in that said Fresnel lens (11) is formed of a material which is previous to infrared radiation in the far range.
10. The infrared intrusion detector as defined in any of claims 7 to 9, characterized in that a prism element (12,13) is arranged adjacent the collecting lens (10, 11) in order to split and multiply the receiving regions (Ai, 2, ... A5).
11. The infrared intrusion detector as defined in- claim 10, characterized in that said prism element (13) is arranged forwardly of said collecting lens.
12. The infrared intrusion detector as defined in claim 2, characterized in that said radiation collecting element (2) has a linear axis; said radiation collecting element (2) is arranged to be rotatable essentially uniformly about said linear axis; and said radiation inlet openings (4) are provided at the surface of said radiation collecting element (2) in a manner such that at different angles of rotation of said rotatable radiation collecting element said openings, during rotation of said radiation collecting element, are brought into the focusing surface (F) at different points in time.
EP81107843A 1980-10-24 1981-10-02 Infrared intrusion detector Expired EP0050750B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT81107843T ATE9412T1 (en) 1980-10-24 1981-10-02 INFRARED INTRUSION DETECTOR.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH7926/80 1980-10-24
CH7926/80A CH650605A5 (en) 1980-10-24 1980-10-24 INFRARED BURGLAR DETECTOR.

Publications (2)

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EP0050750A1 EP0050750A1 (en) 1982-05-05
EP0050750B1 true EP0050750B1 (en) 1984-09-12

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EP81107843A Expired EP0050750B1 (en) 1980-10-24 1981-10-02 Infrared intrusion detector

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US (1) US4429223A (en)
EP (1) EP0050750B1 (en)
JP (1) JPS5797482A (en)
AT (1) ATE9412T1 (en)
AU (1) AU542979B2 (en)
CH (1) CH650605A5 (en)
DE (1) DE3166056D1 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2198842B (en) * 1986-12-19 1991-01-02 Philips Electronic Associated Movement sensing infra-red system
GB2213927A (en) * 1987-12-18 1989-08-23 Philips Electronic Associated Pyroelectric infrared sensors
US5929445A (en) * 1996-09-13 1999-07-27 Electro-Optic Technologies, Llc Passive infrared detector
JP3249419B2 (en) * 1997-03-12 2002-01-21 セイコーインスツルメンツ株式会社 Scanning near-field optical microscope
US6690018B1 (en) * 1998-10-30 2004-02-10 Electro-Optic Technologies, Llc Motion detectors and occupancy sensors with improved sensitivity, angular resolution and range
US6756595B2 (en) * 2000-09-11 2004-06-29 Electro-Optic Technologies, Llc Effective quad-detector occupancy sensors and motion detectors

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Publication number Priority date Publication date Assignee Title
US3703718A (en) * 1971-01-07 1972-11-21 Optical Coating Laboratory Inc Infrared intrusion detector system
CH596621A5 (en) * 1976-06-30 1978-03-15 Cerberus Ag
DE2836462C2 (en) * 1978-08-21 1985-04-18 Richard Hirschmann Radiotechnisches Werk, 7300 Esslingen Room surveillance receiving device

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Publication number Publication date
AU7669381A (en) 1982-04-29
DE3166056D1 (en) 1984-10-18
JPS5797482A (en) 1982-06-17
AU542979B2 (en) 1985-03-28
US4429223A (en) 1984-01-31
ATE9412T1 (en) 1984-09-15
EP0050750A1 (en) 1982-05-05
CH650605A5 (en) 1985-07-31

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