EP0623905A2 - Motion detector - Google Patents

Abstract

The invention relates to an infrared motion detector having an arcuate lens screen (13) which is assembled in front of an infrared sensor (10) and whose lenses (14) in each case cover a monitoring area and focus the radiation of an infrared radiation source, located within the monitoring area, on the infrared sensor (10), the lenses (14) which are located in the central area "X" of the lens screen (13) casting the incident radiation in the direct beam path to the infrared sensor (10), while at least one reflector is provided for detecting laterally incident marginal beams. To avoid gaps in the detection range which are caused by beams which impinge on the rear of the reflector, and furthermore in order to increase the number of monitoring areas so as, for example, also to detect radiation sources which are already located behind the sensor (10), there is arranged in the beam path in front of the sensor (10) a beam splitter which has at least one obliquely placed plane-parallel beam-splitter element (16) whose degree of transmission (transmittance) "T" is greater than or equal to the degree of reflection (reflectance) "R" and to the transmission radiation from the central area "X" of the lens screen impinges in the direct beam path on the sensor (10) and the reflection radiation from the area "Y" of the laterally incident marginal radiation is deflected onto the sensor (10). <IMAGE>

Description

The invention relates to an infrared motion detector with an arc-shaped lens screen mounted in front of an infrared sensor, the lenses of which each capture a monitoring area and focus the radiation from an infrared source located in the monitoring area onto the infrared sensor, the area in the middle of the Lenses located on the lens shield throw the incident radiation directly onto the infrared sensor, while laterally incident marginal rays are directed onto the sensor by reflection.

A passive infrared motion detector is known from EP-PS 0 113 468, which has a symmetrical mirror arrangement of two opposing mirrors, with which a folded beam path is generated and with which the laterally incident edge radiation is deflected onto the infrared sensor. Through this training the azimuth angle of the motion detector can be reached, which is approx. 180 °. This angle can be increased by an appropriate design of the lenses in the lateral area of the lens screen. All in all, infrared sources can be detected that are present in a range of more than 180 ° around the infrared sensor, that is, also infrared sources that are already slightly behind the level of the infrared sensor.

A disadvantage of the mirror arrangement is that it "stands in the way" of the sensor in that the rear of the mirror switches off part of the monitoring areas and thus shadow areas occur in front of the sensor in which the motion detector is ineffective. The shadow areas become larger the more monitoring areas behind the sensor are to be detected. There is a relationship between the size of the mirrors and the dead area. In the known motion detector, the mirrors are therefore moved to achieve a relatively large azimuth angle in the elevation area of the motion detector, which results in a very small elevation angle. Therefore, the area perpendicular to that under the motion detector cannot be detected in the known motion detector.

The object of the invention is to provide a motion detector of the type described in the introduction, in which dead areas or blanking in the monitoring areas are avoided and in which an expansion of the monitoring area to radiation sources located behind the sensor is achieved in a simple manner.

The object is achieved with the features of claim 1 and claim 2. Developments of the invention are described in the subclaims.

Beam splitters make it possible to split a luminous flux or another radiation, for example infrared radiation, into two identical or unequal partial beam currents. This means that, in contrast to the mirror with a degree of transmission 0 and a degree of reflection of approx. 95%, transmission radiation and reflection radiation always occur with a beam splitter. The transmission radiation can be directed onto the sensor, even if the beam splitter lies directly in the incident beam path of the sensor. The attenuation of the radiation by loss of transmission or reflection can be compensated for by a corresponding enlargement of the lenses of the lens screen located in this area. The use of beam splitters in general, and of geometric or physical beam splitters in particular, avoids complicated optical measures for the purpose of deflecting the radiation onto the sensor. Even in the case of multiple transmission or multiple reflection of the incident radiation through or at beam splitters, the residual radiation can still be directed to the sensor in an evaluable size.

With the designs according to the invention, both a detection angle in the azimuth range of more than 180 °, for example 220 °, and an increase in the detection angle in the elevation range compared to the known motion detector can be achieved. By the invention detection angles of more than 180 °, for example of 220 °, can also be achieved in the elevation range, so that all-round reception is made possible.

In the simplest case, an inclined plane-parallel beam splitter element is arranged in front of the infrared sensor, which is located directly in the beam path between the central region of the lens shield and the infrared sensor (claim 1). With this arrangement, the lenses located in the central area of the lens screen throw the incident infrared radiation through the beam splitter directly onto the infrared sensor, while the edge radiation from an edge area of the lens screen adjacent to the central area is directed through the beam splitter according to its degree of reflection onto the infrared Detector is deflected, specifically from the edge region of the lens screen, to which the beam splitter element is arranged inclined. If the central area of the lens screen is limited by the detection angle specified by the infrared sensor, then the overall monitoring area is extended to the edge area of the lens screen by this arrangement. Such a motion detector can, for example, detect areas facing forwards and areas pointing vertically downwards, as a result of which creep protection is achieved.

As already explained, the density of the monitoring areas is determined by the number of lenses of the lens screen. The greater the density of the monitoring areas, the more lenses the lens screen has. It follows from this that in the beam path of each lens of the area, side incident incident radiation, that is to say that Radiation from the edge region of the lens screen, which does not fall directly on the sensor, a beam splitter element is provided for deflecting the edge radiation onto the sensor.

An increase in the number of monitoring areas can be achieved if, instead of only one beam splitter element, two or more beam splitter elements are used, which are combined to form a beam splitter, according to claims 11, 12, 13, 14 and 15. With an arrangement of the beam splitter according to claim 11 an azimuth angle of the motion detector of 220 ° can be achieved. The elevation angle of the motion detector can be expanded to 220 ° by appropriately supplementing this arrangement with two further beam splitter elements to form a pyramid-shaped beam splitter. By further dissolving this arrangement, by facet-like configurations of the beam splitter elements according to claim 17, monitoring areas extending around the motion detector can finally be formed in the fastening plane of the motion detector.

Claims 12 and 13 in conjunction with claim 11 show two examples of the interaction of the beam splitter with the sensor. The deflection of the laterally incident marginal rays takes place differently according to claim 12 than according to claim 13. A beam from the lateral area of the lens shield striking the beam splitter (according to claim 12) is divided by the leg of the beam splitter lying in the direction of incidence into one by the divider ratio T: R fixed transmission component and a reflection component. The transmission component of the radiation is likewise divided into a transmission component and a reflection component on the second leg opposite the first leg of the beam splitter. The reflection portion of the transmission portion from the first leg is redirected to the sensor by the second leg.

In the arrangement according to claim 13, the beam is also divided into transmission and reflection components in accordance with the division ratio. In contrast to the arrangement according to claim 12, however, the reflection component is already deflected from the incident beam through the first leg of the beam splitter to the sensor, as a result of which the radiation component deflected onto the sensor can be increased.

Finally, an arrangement of the beam splitter according to claim 11 is also conceivable, in which the tip or the apex of the beam splitter is directed toward the lateral region of the lens screen, for example from the position facing with its tip towards the sensor (according to claim 13) after a 90 ° rotated position.

The solution according to claim 2 differs from the solution according to claim 1 in that no beam splitter needs to be arranged in the direct beam path between the lenses in the central region of the lens screen and the infrared sensor, that is, the incident infrared radiation directly onto the sensor falls. The beam splitter is arranged in such a way that it deflects the edge radiation incident laterally through the lens screen onto the sensor. To do this are the individual Beam splitter elements, for example two beam splitter elements arranged symmetrically to the sensor, are provided, which are inclined towards the sensor, so that the edge radiation incident from the lateral regions of the lens current either falls directly onto the surface of a beam splitter element facing the sensor and is deflected onto the sensor or onto one Beam splitter element falls, the transmission radiation of which falls on the other beam splitter element, the reflection radiation of which is deflected onto the sensor. This design prevents shadowing in the monitoring areas, since the beam splitter element, in contrast to a mirror, is transparent to the infrared radiation from both sides. Despite the relatively large transmission or reflection losses, in particular in the case of multiple transmission and / or multiple reflection, which occur when two or more beam splitter elements interact, the range or response sensitivity can be kept constant in all monitoring areas by enlarging the corresponding lenses of the lens screen. In order to achieve all-round sensitivity, in a further embodiment of claim 2, the beam splitter can consist of individual elements composed of a truncated cone or a truncated pyramid. A greater density of the reception areas results if more than four individual elements are arranged in a facetted manner around the sensor.

According to the different use and arrangement of the beam splitter according to claims 1 and 2, different beam splitter ratios are advantageous. As advantageous for the invention according to claim 1 there is a beam splitter ratio transmission to reflection T: R in the range from 4: 1 to 7: 3. In the embodiment according to claim 2, a division ratio T: R = 1: 1 is advantageous because it allows a maximum of residual radiation to be directed to the sensor.

A beam splitter made of silicon or germanium is suitable for a selective design of the beam splitter for a spectral range of 7 to 14 micrometers wavelength. These are flakes made of silicon or germanium of 0.1 to 0.5 mm thickness, which are provided on one side, preferably on the reflection side, that is to say on the side facing the sensor, with a reflective layer. The beam splitter elements can be produced from a wafer in different sizes and dimensions. Furthermore, holographic imaging components can be used which have a higher efficiency than beam splitters made of silicon.

To reduce the absorption of the beam splitter, the beam splitter is provided on the side facing the incident beam path with a multi-layer system (alternating layers), on which multiple reflection occurs, so that the absorption is reduced and the reflection is increased. By integrating the beam splitter into the sensor or into the sensor element, a separate sensor filter can be dispensed with.

A development of the invention according to claim 1 provides two infrared sensors arranged side by side according to claim 14, which with a beam splitter and Lens screen form an electro-optical system. In this case, an approximately hemispherical lens screen with a number of individual lenses distributed over the surface covers the infrared sensors arranged in the center, so that one sensor lies in the focal point of the individual lenses of the lens screen located in a half field. The individual lenses can be Fresnel lenses or convex lenses.

If the two sensors are tilted away from each other, the two receiving lobes can already cover a range of 180 °. An increase in the number of reception areas is then only necessary for monitoring areas that are behind the sensor. In this case, it may be sufficient to provide an additional rearward monitoring area for each sensor. Correspondingly, a beam splitter element is then to be provided in the beam path in front of each sensor, the reflection radiation of which is deflected from the laterally incident edge radiation onto the respective sensor.

The lengthening of the beam path requires an increase in the focal length of the lenses in the edge region of the lens screen compared to the lenses in the central area of the lens screen in order to focus this edge radiation on the sensor. Despite the beam splitter elements arranged in the direct beam path of the central area of the lens screen, no blind spots are generated in the monitoring areas, since depending on the splitting ratio of the steel splitter, for example, 50%, 60%, 70% or 80% of the transmission radiation is directed directly to the sensors.

In order to enable the beam splitter elements to be fixed and adjusted, a holder is provided to which the beam splitter elements are attached. The holder should have the smallest possible dimensions and have no influence on the monitoring areas. The holder itself is advantageously made of an infrared radiation-transmissive material.

Finally, reference is made to the possibility of either capturing the reflection or transmission component of the incident radiation by means of a further sensor, according to claim 25. The beam splitter elements are preferably flat plates, but concave or convex curved plates can also be used.

Fig. 1

eine schematische Darstellung einer ersten Ausführung des Bewegungsmelders mit einem in den direkten Strahlengang des Sensors eingefügten Strahlenteiler,

Fig. 2

eine Zweite Ausführung mit zwei sich gegenüberliegenden Strahlenteilerelementen,

Fig. 3

eine weitere Ausführung mit einem winkligen Strahlenteiler,

Fig. 4

eine andere Ausführung, bei der die seitlich einfallende Randstrahlung durch ein erstes Strahlenteilerelement hindurchgeht und dessen Transmissionsstrahlung an einem zweiten Strahlenteilerelement durch Reflexion auf den Sensor gelenkt wird,

Fig. 5

eine weitere Ausführung mit einem facettenartig ausgebildeten Strahlenteiler,

Fig. 6

die Draufsicht auf die Ausführung nach Fig. 5,

Fig. 7

eine Ausführung des Bewegungsmelders mit zwei Sensoren,

Fig. 8

ein Detail der Ausführung nach Fig. 7 mit einem Halter für die Strahlenteilerelemente,

Fig. 9

die Seitenansicht der Fig. 8.

Several embodiments of the invention are described in more detail below with reference to the drawings. Show it:

Fig. 1

1 shows a schematic representation of a first embodiment of the motion detector with a beam splitter inserted into the direct beam path of the sensor,

Fig. 2

a second embodiment with two opposing beam splitter elements,

Fig. 3

another version with an angled beam splitter,

Fig. 4

another embodiment in which the side incident incident radiation passes through a first beam splitter element and its transmission radiation at a second beam splitter element is directed to the sensor by reflection,

Fig. 5

another version with a faceted beam splitter,

Fig. 6

the top view of the embodiment of FIG. 5,

Fig. 7

a version of the motion detector with two sensors,

Fig. 8

7 shows a detail of the embodiment according to FIG. 7 with a holder for the beam splitter elements,

Fig. 9

the side view of Fig. 8th

It should first be noted that only those parts of a motion detector are shown and subsequently described in the figures of the drawings which are important for understanding the invention. All modules of the motion detector, not shown, can have a structure known per se. The figures, for example, lack the evaluation circuit which processes the signals from the infrared sensor. The housing of the motion detector is also missing. In the figures of the drawings, the same parts are identified with the same reference numbers.

Figures 1 to 6 show schematically the optoelectronic arrangement of a motion detector with a conventional infrared sensor 10 with two adjacent sensor elements 11. The sensor is provided on a holder, for example one with conductor tracks Board 12, assembled. Such an infrared sensor 10 is sensitive to infrared sources within a lobe-like sensitivity range, which includes a detection angle of approximately 110 °, while it is not sensitive to infrared sources lying outside the receiving lobe.

In front of the sensor 10 there is a lens screen 13 with many individual lenses 14 arranged on its surface, each of which detects a monitoring area and focuses the radiation from an infrared radiation source located in the monitoring area onto the infrared sensor 10. The lenses can be designed as Fresnel lenses or as convex lenses. In the exemplary embodiments, the lens shade 13 has a hemispherical shape. Of course, the lens shade can also have a differently curved surface.

In the central region "X" of the lens screen, which lies within the receiving lobe of the sensor 10, the infrared radiation incident through the lenses 14 can be focused directly on the sensor.

In order to make the sensor 10 sensitive to infrared radiation sources located outside its reception lobe, the lateral edge rays incident in the region "Y" of the lens screen 13 are deflected so that they then run inside the reception lobe of the sensor 10 and are deflected onto the sensor can.

In Fig. 1 of the drawing are in the direct beam path, ie in the beam path in the area "X" of the lens hood 13 incident beams 15, 15 ', 10 slanted beam splitter elements 16, 16' arranged in front of the sensor, consisting of plane-parallel silicon chips. These beam splitter elements 16, 16 'have a splitter ratio of 7: 3, ie their transmittance is 70% and their reflectance is 30%. The beam splitter element 16 is inclined relative to the sensor to such an extent that a beam 17 of a radiation source located behind the sensor 10 falls on the beam splitter element 16 and its reflection radiation is directed onto the sensor 10. Another beam splitter element 16 'assumes a different position with respect to the sensor 10, so that a further beam bundle 17' of a radiation source approximately at right angles to the normal of the sensor falls on the beam splitter element 16 'and its reflection radiation is deflected onto the sensor. In Fig. 1, only two beam splitter elements 16, 16 'for two beams 17, 17' are shown. Additional beam splitter elements are to be provided for further beams that are incident laterally. The same also applies to the embodiments described with reference to the following FIGS. 2 to 7. Corresponding to the divider ratio, 70% transmission radiation from a central bundle "X" of the lens screen 13 and striking the beam splitter element 16, 16 'is directed directly to the sensor 10. 30% of reflection radiation is deflected onto the sensor 10 by a beam 17, 17 'coming from the lateral region "Y" of the lens screen 13 and striking the beam splitter element 16, 16'. The relatively high transmission and reflection losses that occur affect the sensitivity or range within the corresponding reception area, but there are no dead areas in which the sensor would be completely hidden. It should also be noted that a shorter range of the motion detector in the area of the incident side radiation compared to the radiation incident in the main direction is quite desirable. Range adjustment, in particular in the main direction, that is to say in the central region “X”, can also be brought about by a “sharper” lens 14 compared to those lenses whose beams do not fall on the beam splitter element 16.

A motion detector designed according to FIG. 1 can, in addition to the forward-facing reception lobe, be equipped with a further reception lobe running perpendicularly to it, which serves, for example, as a creep protection.

The relationships listed here based on the division ratio T: R = 7: 3 naturally also apply to other division ratios, for example for a division ratio of T: R = 4: 1. In order not to influence the sensitivity in the main direction too much, the transmittance should not be less than 50%. This also applies to the other versions, with the exception of the version according to FIG. 4, in which it should be approximately 50%, as will be explained in more detail below.

In FIG. 2, two opposing plane-parallel beam splitter elements 18, 18 'are arranged in front of the sensor 10 by way of example. Your inclination to each other takes place in such a way that the intersection "A" resulting in the extension of the beam splitter element planes lies on the side of the beam splitter elements 18 facing away from the sensor 10, the effective reflection surfaces are inclined towards the sensor 10. With this arrangement, lateral radiation sources or radiation sources already lying behind the plane of the sensor 10 can be detected by two opposite edge regions “Y” of the lens screen 13. The beam 19 incident on the right of the sensor 10 strikes the beam splitter element 18 'located on the left of the sensor 10 and throws the reflection radiation onto the sensor or the beam 20 incident on the left of the sensor 10 falls on the beam splitter element 18 located on the right of the sensor 10, which reflects its reflection radiation throws the sensor.

From Fig. 2 it can also be seen that infrared radiation incident from the central region "X" of the lens screen falls directly on the sensor 10 or strikes a beam splitter element 18, 18 'and the transmission radiation of this beam splitter element falls on the sensor. According to FIG. 2, the beam 21 falls directly onto the sensor without hitting a beam splitter element, while the beam 22 initially hits the beam splitter element 18 and its transmission component falls on the sensor 10. With this arrangement, the number of monitoring areas of the motion detector can be increased and the detection angle in the azimuth range can be expanded to approximately 220 ° to 230 °.

A similar embodiment is shown in FIG. 3. An angular beam splitter 23 is made up of two beam splitter elements 24, 24 ', the tip of which is directed towards the sensor 10. In contrast to the embodiment according to FIG. 2, the beam 25 incident on the right of the sensor 10 strikes the beam splitter element 24 on the right of the sensor, the reflection radiation of which is deflected onto the sensor. Likewise, the beam splitter element 26 located to the left of the sensor 10 strikes the beam splitter element 24 ′ located to the left of the sensor 10, the reflection radiation of which strikes the sensor 10. The center of the central region of the lens screen 13 is covered by the beam splitter 23 in this arrangement. All beams 27 incident in this area first strike the beam splitter 23, penetrate it and then hit the sensor 10. In this case too, the loss due to reflection can be compensated for with “sharper” lenses 14.

4, a different principle is used for the beam deflection than in the other exemplary embodiments, although the arrangement is identical to the embodiment according to FIG. 2. In this embodiment, there is no need for a beam splitter arranged in the direct beam path in front of the sensor 10. The infrared radiation incident from the central region “X” of the lens screen 13, shown here as an example as a beam 28, strikes the sensor 10 directly.

A beam splitter 31 with a symmetrical arrangement of two beam splitter elements is used to detect edge radiation incident laterally from the regions “Y”, shown here as a beam 29,30 32,32 'used. The beam splitter elements 32, 32 'are arranged in a plane in front of the sensor and coaxial with it. The beam splitter elements 32, 32 'are arranged with such an inclined position that their effective reflector surfaces are inclined towards the sensor 10. The inclination is determined from the sine law of the optics.

In contrast to FIG. 2, the beam element 29 incident on the right of the sensor 10 first strikes the beam splitter element 32 located on the right of the sensor 10, the transmission radiation of which is reflected on the beam splitter element 32 ′ located on the left of the sensor. The reflection radiation of the beam 29 is directed onto the sensor 10. Likewise, the beam bundle 30 incident to the left of the sensor 10 first strikes the beam splitter element 32 ', the transmission radiation of which strikes the beam splitter element 32 to the right of the sensor 10. The reflection radiation of the beam 30 is directed onto the sensor 10. If the splitter ratio of the beam splitter elements 32, 32 'T: R = 1: 1, then 25% of the radiation from the beams 29, 30 reaches the sensor. With a division ratio of T: R = 3: 2 or T: R = 7: 3 or T: R = 4: 1, it is 24% or 21% or 16%. This effective evaluable radiation component is sufficiently large for a range that is reduced in the central region “X” of the lens screen compared to the main reception direction.

FIGS. 5 and 6 show an example of an embodiment in which the monitoring areas of laterally incident beams of rays are for all other designs 35 extend around the sensor 10. This all-round sensitivity is achieved by a beam splitter 33, whose beam splitter elements 34 are composed in a facet-like manner. In the exemplary embodiment, the beam splitter 33 consists of eight beam splitter elements 34. Each beam splitter element 34 interacts with a lens 14 in the edge region "Y" of the lens screen 13. The more interacting beam splitter elements 34 and lenses 14 are present, the closer the individual monitoring areas are.

Otherwise, the embodiment according to FIGS. 5 and 6 represents a further development of the embodiment according to FIG. 3. Repetition of the further details can therefore be dispensed with. It should only be mentioned that for the purpose of detecting many monitoring areas from the lateral area "Y", the beam splitter 33 can be formed by several circumferential facet planes, so that not only radiation incident from the edge area of the lens screen 13 can be detected, but also that from the Areas "Y" of the lens screen that are adjacent to the central area "X" but are not in the direct detection area of the sensor 10.

FIG. 7 shows an embodiment with two sensors 10, which are arranged at an angle to one another, each sensor 10 detecting a half field of the lens screen 13. Due to the angular position, the focal lengths of the lenses 14 of the ideal lens screen 36 shown in broken lines are approximated and by a hemispherical or semi-cylindrical lens screen 13. With the two sensors 10, an azimuth monitoring area can be obtained of more than 180 °. With the beam splitter elements 37, 37 ', the lateral areas are expanded by areas which are already behind the sensors 10, so that the radiation 38 from an infrared radiation source lying to the right behind the right sensor 10 onto the right sensor 10 or the radiation 39 from the left radiation source located behind the left sensor 10 can be deflected to the left sensor 10. Radiation coming from the central area of the lens screen 13 strikes one of the two sensors 10 as transmission radiation. The reflection losses of this radiation are compensated for by enlarging the lenses 14 in this area of the lens screen 13. With this solution, the number of monitoring areas is increased by two, which extends the reception range of the motion detector to approx. 240 °. The beam splitter elements 37, 37 'of the beam splitter 47 are fastened to a holder 40 arranged between the sensors 10.

Figures 9 and 10 show the design of the holder 40 and the attachment of the beam splitter elements 37,37 'in detail. The shape of the holder 40 is bow-like. It has a crossbar 41 with locking arms 42 hanging down at the ends. With the locking arms, the holder 40 is inserted into guides of a base 43, which are not described in any more detail, wherein in the end position, notches 44 engage in a form-fitting manner in locking receptacles of the base 43, not shown. For the mounting and adjustment of the beam splitter elements 37, 37 ', receptacles 45 are provided in the crosspiece 41, in each of which one end of the beam splitter element 37, 37' is inserted and clamped by a fitting 46. The connection can be secured with an adhesive. In practice, the holder 40 and the beam splitter element 37, 37 'are manufactured as a pre-assembled structural unit and attached to the base 43.

Claims (25)

Infrared motion detector, with an arcuate lens screen (13) mounted in front of an infrared sensor (10), the lenses (14) each of which detect a monitoring area and concentrate the radiation from an infrared source located in the monitoring area on the infrared sensor, the Lenses located in the central region (X) of the lens screen (13) direct the incident radiation directly to the infrared sensor (10), while incident lateral rays are directed by reflection onto the sensor (10),
characterized,
that a beam splitter with at least one beam splitter element (16, 16 '; 18, 18'; 24, 24 ';34; 37, 37') is arranged in the beam path in front of the infrared sensor (10), which consists of the central region (X ) of the lens screen (13) passes incident radiation as transmission radiation in the direct beam path onto the sensor (10) and deflects the incident radiation from the lateral edge region (Y) as reflection radiation onto the sensor (10). Infrared motion detector, with an arcuate lens screen (13) mounted in front of an infrared sensor (10), the lenses (14) each of which detect a monitoring area and concentrate the radiation from an infrared source located in the monitoring area on the infrared sensor, the lenses located in the central region (X) of the lens screen (13) direct the incident radiation directly to the infrared sensor (10), while laterally incident marginal rays are directed onto the sensor (10) by reflection,
characterized,
that in the beam path of the edge radiation incident from the edge region (Y) of the lens screen (13) there is arranged a beam splitter with at least two opposing, diagonally positioned beam splitter elements (32, 32 ') which detects the beams from the central area (X) of the lens screen (13) incident radiation between the beam splitter elements (32, 32 ') and the edge radiation incident from the lateral edge region (Y) passes through the one beam splitter element as transmission radiation to the opposite beam splitter element, from which the radiation is directed as reflection radiation onto the sensor (10). Infrared motion detector according to claim 1 or 2, characterized in that in the beam path of each lens (14) of the edge region (Y) of the lens screen (13) a beam splitter element (16,16 '; 18,18'; 24, 24 '; 34; 37, 37 ') is provided for deflecting the edge radiation onto the sensor (10). Infrared motion detector according to claim 1, characterized in that the division ratio T: R of the beam splitter element (16, 16 '; 18, 18'; 24, 24 ';34; 37.37 ') is greater than 2: 1, where T is the transmittance and R is the reflectance. Infrared motion detector according to claim 4, characterized in that the division ratio T: R of the beam splitter element is approximately 7: 3. Infrared motion detector according to claim 2, characterized in that the divider ratio T: R of the beam splitter element (32, 32 ') is approximately 1: 1, T being the transmittance and R being the reflectance. Infrared motion detector according to one of claims 1-6, characterized in that the base material of the beam splitter consists of silicon or germanium. Infrared motion detector according to one of claims 1-6, characterized in that the beam splitter is a holographically imaging component. Infrared motion detector according to one of claims 1-8, characterized in that the beam splitter has a plurality of reflection layers. Infrared motion detector according to one of claims 1-9, characterized in that the beam splitter is contained in the housing of the sensor (10). Infrared motion detector according to one of claims 1-10, characterized in that the beam splitter (23) is angled with a tip or apex. Infrared motion detector according to claim 11, characterized in that the beam splitter is arranged like a roof, opposite the sensor (10). Infrared motion detector according to claim 12, characterized in that the beam splitter (23) is arranged with the tip or the apex directed towards the sensor (10). Infrared motion detector according to one of claims 1-13, characterized in that two sensors (10) are arranged side by side, each of which one sensor receives the radiation from a sector of the lens screen (13) and each sensor (10) has at least one beam splitter element ( 16.16 '; 18.18'; 24.24 '; 34; 37.37'). Infrared motion detector according to one of claims 1-14, characterized in that the beam splitter (23, 33, 47) consists of two individual elements (16, 16 '; 18, 18'; 24, 24 '; 32, 32'; 37, 37 '). Infrared motion detector according to one of Claims 1, 14 and 15, characterized in that a single element (37, 37 ') of the beam splitter (47) is arranged in the beam path in front of each sensor (10). Infrared motion detector according to one of claims 1-16, characterized in that the beam splitter (23,33) is composed of several individual elements (16,16 ';18,18'; 24,24 ';32,32';34; 37,37 '). Infrared motion detector according to one of claims 1-17, characterized in that the beam splitter elements (16, 16 '; 18, 18'; 24, 24 '; 32, 32'; 34; 37, 37 ') of the beam splitter (23, 33, 47) are attached to a holder (40). Infrared motion detector according to claim 18, characterized in that the cooler (40) is designed like a bow and has latching arms (42). Infrared motion detector according to claim 18 or 19, characterized in that the cooler (40) with the latching arms (42) is inserted in receptacles of a base (43). Infrared motion detector according to one of Claims 18-20, characterized in that the beam splitter elements (37, 37 ') are fastened to a transverse web (41) of the holder (40). Infrared motion detector according to claim 21, characterized in that the transverse web (41) has receptacles (45) for the beam splitter elements (37, 37 '). Infrared motion detector according to Claim 22, characterized in that the beam splitter elements (37, 37 ') are secured by a fitting piece (46) which overlaps the receptacles (45). Infrared motion detector according to claim 22 or 23, characterized in that the beam splitter elements (37, 37 ') are inserted laterally into the receptacles (45). Infrared motion detector according to one of Claims 1-24, characterized in that a plurality of sensors (10) are arranged at an angle to one another such that at least one sensor (10) is located in the beam path of the transmission radiation from the beam splitter (23, 33, 47) and in the beam path the reflection radiation of the beam splitter at least one further sensor (10) is arranged.

Images