Movement detector

Description

[0001] The invention relates to a motion detector. Motion detectors are generally known from the prior art. A motion detector is often used to detect movement in a room or outdoor area and, in response to the detected movement, to switch an electrical circuit, for example, turning on a light or sending a corresponding signal to a monitoring unit to initiate follow-up measures.

[0002] If a motion detector is used to monitor an indoor or outdoor surveillance area, there is a risk that the motion detector will be tampered with to prevent motion from being detected in the surveillance area. In practice, it has been observed that one example of tampering is the removal or removal of a motion detector head unit. This head unit often contains the motion detector sensor. If the sensor is removed or removed, no motion can be detected.

[0003] From EP 0 012 280 A1, a motion detector is also known which has a base unit and a head unit, wherein the head unit has a sensor which is designed for contactless detection of a detection area and for generating a sensor signal based thereon, wherein the head unit is fastened to the base unit in a force-fitting and / or form-fitting manner in a predetermined fastening position, so that the sensor is connected to an evaluation unit in the head unit in order to transmit the sensor signal from the sensor to the evaluation unit.The base unit has a detector arranged and configured to detect whether the head unit is either attached to the base unit in the predetermined attachment position or in a tamper position deviating from the predetermined attachment position, wherein the detector is configured to generate a detector signal representing whether the head unit is either in the attachment position or in the tamper position.

[0004] The invention is based on the object of proposing a design of a motion detector which is robust against sabotage and which allows residual functionality of the motion detector in the event of sabotage.

[0005] The object is achieved according to a first aspect of the invention by a motion detector having the features of claim 1. Thus, a motion detector is provided which has a base unit and a head unit. The head unit has a sensor which is designed for the contactless detection of a detection area and for generating a sensor signal based thereon. The sensor is coupled to a first connection of the head unit. The base unit has an evaluation unit which is coupled to a second connection of the base unit. The head unit is fastened to the base unit in a force-fitting and / or form-fitting manner in a predetermined fastening position, such that the first connection of the head unit is detachably connected to the second connection of the base unit in order to transmit the sensor signal from the sensor to the evaluation unit.The base unit also has a detector arranged and configured to detect whether the head unit is either attached to the base unit in the predetermined fastening position or in a tamper position deviating from the predetermined fastening position. The detector is configured to generate a detector signal representing whether the head unit is either in the fastening position or in the tamper position. The detector is coupled to the evaluation unit to transmit the detector signal to the evaluation unit. The evaluation unit is configured to switch a switch, in particular a semiconductor switch or a relay, of the base unit when the detector signal represents the tamper position.The first terminal and the second terminal are designed as plug-in connection means which engage with each other when the head unit is brought into the predetermined fastening position in order to establish the connection to the base unit.

[0006] As already explained in the introduction, sabotage of a motion detector, which is preferably used to monitor a detection area, often occurs in such a way that at least the sensor of the motion detector is separated from the rest of the motion detector. The sensor of the motion detector according to the first aspect of the invention forms part of the head unit, which is fastened to the base unit in a force-fitting and / or form-fitting manner in the predetermined fastening position. The fastening of the head unit to the base unit can be designed such that the force-fitting and / or form-fitting connection between the head unit and the base unit forms a predetermined breaking point, which tears open if the sensor of the head unit and / or the head unit is forcibly separated and / or torn off from the motion detector.The base unit is preferably designed to be fastened to a wall, ceiling and / or other fixed element in a force-fitting and / or form-fitting manner. If the head unit is pulled in order to tear off the sensor of the motion detector, the head unit is separated from the base unit. However, this forcible pulling causes the head unit to transition from the fastening position to the tamper position. The detector of the base unit is designed and arranged to detect whether the head unit is either in the fastening position or in the tamper position. In the example given, the detector therefore detects the tamper position of the head unit and generates a detector signal that represents the tamper position of the head unit.Because the detector and evaluation unit are located in the base unit of the motion detector, they remain undamaged even if the head unit of the motion detector is forcibly removed. Even if part of the functionality of the motion detector is no longer available due to the forcible removal of the motion detector's sensor, the motion detector retains at least some of the functionality provided by the detector and evaluation unit. The detector is coupled to the evaluation unit to transmit the detector signal to the evaluation unit. This occurs in particular when the detector has detected a tamper position. The detector and evaluation unit can be coupled to one another, for example, via a signal connection, via which the detector signal is transmitted from the detector to the evaluation unit. Other designs are also possible.For example, the detector can be arranged on the same circuit board as the evaluation unit, so that the signal can be transmitted from the detector to the evaluation unit via the circuit board.

[0007] The evaluation unit can have a processor unit that is designed to evaluate the detector signal. In particular, the processor unit of the evaluation unit can be configured to detect the tamper position based on the detector signal and, in response thereto, to cause the switch of the base unit to switch. The switch can be designed, for example, as a relay or as a semiconductor switch, in particular a MOSFET. By switching the switch, an electrical circuit can be closed to signal that the head unit of the motion detector is in a tamper position. This can additionally or alternatively signal that the motion detector has been tampered with. This information can, for example, be passed on to a higher-level monitoring unit via the switching of the switch in order to initiate follow-up measures.If the switch signals that the motion detector has been tampered with, particularly that the head unit is in a tamper position, this can be interpreted as an alarm signal equivalent to detected movement in the detection area and triggers appropriate follow-up actions in an alarm system. However, the switch activated due to the tamper position can also be used to connect a light source to an electrical power source, particularly in such a way that at least the detection area is also illuminated by the light source. This can serve as a deterrent to prevent further violent actions.

[0008] In other words, the detector can detect a tamper position of the head unit and, in response, activate the switch of the base unit. The switch can, for example, be coupled to at least one lamp to switch when the tamper position is detected and supply the at least one lamp with electrical power. This can provide particularly simple yet effective protection against further tampering, or at least increase the overcoming point to prevent further tampering.

[0009] The evaluation unit of the base unit is also coupled to the second connection of the base unit. This can also be done via a signal line. The second connection of the base unit is preferably only detachably connected to the first connection of the head unit when the head unit is fastened to the base unit in a force-fitting and / or form-fitting manner in the predetermined fastening position. The detachable connection between the first connection and the second connection is preferably designed such that a sensor signal generated by the sensor is transmitted to the evaluation unit via the first and second connections. The sensor can be coupled to the first connection via a signal connection. In particular, this is formed by a signal line between the sensor and the first connection. The evaluation unit can also be configured to detect movement in the detection area based on the sensor signal.Furthermore, the evaluation unit can be configured to switch the previously explained switch or another switch of the base unit when the evaluation unit detects movement in the detection area. Reference to a switch below preferably does not refer to the other switch of the base unit, but rather to the previously explained switch of the base unit, which is switched when the detector signal represents the tamper position.

[0010] An advantageous embodiment of the motion detector is characterized in that the sensor is designed as an infrared sensor, an ultrasonic sensor, or a sensor for emitting and detecting electromagnetic waves. The infrared sensor can preferably be designed as a so-called pyroelectric sensor (PIR sensor). The pyroelectric sensor can, for example, be designed to detect thermal radiation in the infrared range. The ultrasonic sensor can, for example, be designed to generate and emit ultrasonic waves and to detect reflected ultrasonic waves. In each of the aforementioned advantageous embodiments, the sensors are designed to generate a sensor signal. For example, the infrared sensor can be designed to generate a sensor signal that represents the thermal radiation or change in thermal radiation detected by the infrared sensor.The ultrasonic sensor can, for example, be configured to represent the detected, reflected ultrasonic waves. Finally, the sensor configured to detect electromagnetic waves can also be configured to generate a sensor signal that represents the detected electromagnetic waves.

[0011] The head unit's sensor can be mounted in or on the head unit in such a way that the sensor can detect the detection area without contact. For example, if the sensor is designed as an infrared sensor, the sensor can be mounted in the head unit so that the sensor can detect the detection area through a protective cap that is permeable to infrared radiation.

[0012] An advantageous embodiment of the motion detector is characterized in that the sensor is designed to detect a change in the temperature of an object in the detection area, so that the sensor signal represents the temperature of the object or a temperature change in the object. The sensor signal can be transmitted to the evaluation unit. The sensor and the evaluation unit can be designed for this purpose. The previously explained signal connections as well as the first and second connections are also used, in particular, to transmit the sensor signal.

[0013] A further advantageous embodiment of the motion detector is characterized in that the sensor is designed to detect the movement of an object in the detection zone, so that the sensor signal represents the detected movement of the object. The movement of the object can be represented directly or indirectly by the sensor signal. For example, the sensor cells of the sensor can be designed such that a signal above a threshold value is only generated when the object moves within the detection zone. Alternatively or additionally, the movement of the object can be represented at least indirectly from the temporal profile of the sensor signal.

[0014] A further advantageous embodiment of the motion detector is characterized in that the evaluation unit is designed to detect movement in the detection area based on the sensor signal. Furthermore, it is preferably provided that the evaluation unit is designed to switch the switch when the evaluation unit detects movement in the detection area. This switch can be the same switch that is switched by the evaluation unit when the detector signal represents the tamper position. However, it is also possible for a different switch to be switched by the evaluation unit when the evaluation unit detects movement in the detection area. The evaluation unit can, for example, be designed to perform pattern recognition based on the sensor signal in order to detect movement in the detection area.However, it is also possible for the evaluation unit to perform other evaluation mechanisms. For example, a movement can be detected if a value represented by the sensor signal exceeds a predetermined threshold. If the movement is positively detected by the evaluation unit, the aforementioned switch is switched by the evaluation unit based on this. The switch is also part of the base unit. Thus, the switch can be arranged together with the evaluation unit on a circuit board. The switch is preferably a semiconductor switch or a relay.

[0015] A further advantageous embodiment of the motion detector is characterized in that the detector is designed as a contact switch or as a proximity switch. The detector can be attached to or in the base unit in such a way that the detector designed as a switch is in a first switching position when the head unit is attached to the base unit in the predetermined fastening position, and that the detector designed as a switch is in a second switching position when the head unit is in the tamper position, which differs from the fastening position. For example, the detector designed as a switch can be arranged in such a way that the head unit acts directly or indirectly on the detector when the head unit is attached to the base unit in the fastening position, and that this effect on the detector is interrupted when the head unit is in the tamper position.If the detector is designed as a contact switch, the action can be a direct mechanical action on the contact switch. For example, the head unit can press directly on the contact switch when the head unit is attached to the base unit in the fastening position and is completely or partially mechanically detached from the contact switch when the head unit is in the tamper position. This makes it particularly easy to change the contact switch between the first and second switch positions. However, direct mechanical contact between the detector and the head unit to detect whether the head unit is in the predetermined fastening position or in the tamper position is not absolutely necessary. In one advantageous embodiment, the detector can also be designed as a proximity switch.The proximity switch can detect whether the head unit is in the fastening position or in the tamper position without touching the head unit. For example, the proximity switch can be arranged opposite the head unit on the base unit, so that the proximity switch is set to a first switching position when the head unit is fastened to the base unit in the fastening position. The proximity switch is set to the second switching position when the distance between the head unit and the base unit is increased due to tampering, so that the head unit is in a tamper position. This tamper position can therefore be detected at least indirectly by the second switching position of the proximity sensor. The detector can be designed to generate a detector signal that represents the first or second switching position of the detector.The evaluation unit can be configured to detect the switching position of the detector based on the detector signal. Furthermore, the evaluation unit can be configured to detect the tamper position based on the detected switching position of the detector.

[0016] A further advantageous embodiment of the motion detector is characterized in that the sensor is arranged in a sensor head of the head unit, wherein the sensor head is fastened to a fastening section of the head unit, and wherein the fastening section is fastened to a front side of the base unit in a force-fitting and / or form-fitting manner by an associated rear side. The head unit can be connected to the fastening section via a joint, such that the head unit can be pivoted within a predetermined angular range relative to the fastening section. Since the sensor is arranged in the sensor head, a detection range of the motion detector can be defined by pivoting the head unit.Because the sensor is located in the head unit, which in turn is connected to the head unit's mounting section, this ensures that if someone attempts to tamper with the motion detector by force, there is a high probability that the head unit will be separated from the base unit. The head unit, and in particular the associated mounting section, can be attached to the base unit using connecting means. For example, the head unit and the base unit can be connected to one another using screws. Alternatively or additionally, locking lugs can be formed on the rear of the mounting section or on the front of the base unit, which can engage and lock into opposing locking grooves to create a force-fitting and form-fitting connection between the head unit and the base unit.Other connection types and / or connecting means for force-fitting and / or form-fitting the head unit to the base unit are also possible. The connecting means as such and / or the respective fastening to the head unit and / or base unit can be designed such that, upon reaching a predetermined tensile force, the connection between the head unit and the base unit breaks, so that the head unit is separated as a whole from the base unit. In other words, the connection between the head unit and the base unit can be designed such that a predetermined breaking point is provided, which breaks open in the event of tampering with the motion detector, allowing the head unit to be separated from the base unit.This offers the advantage that the detector and the evaluation unit remain in the base unit and can detect the corresponding detection of the tamper position and pass it on by switching the switch.

[0017] A further advantageous embodiment of the motion detector is characterized in that a pin of the head unit is formed and arranged on the rear of the fastening section of the head unit, such that the pin only acts on the detector in a predetermined pin position when the head unit is fastened to the base unit in the predetermined fastening position, such that the detector is designed to detect the predetermined fastening position or the tamper position via the action of the pin on the detector. The pin can have a rod shape, wherein the pin can protrude beyond the rear of the fastening section. The front side of the pin can act on the detector directly or indirectly. A direct action of the pin on the detector is advantageous, for example, when the detector is designed as a contact switch.If, on the other hand, the detector is designed as a proximity switch, an indirect effect of the pin on the detector may be sufficient to detect the fastening position or the tamper position. For example, the pin can be designed and arranged in such a way that the pin only moves the proximity switch into the first switching position when it is in the predetermined pin position. If the head unit is sabotaged so that the pin is no longer in the predetermined pin position but is positioned away from the proximity switch due to a relative movement, the proximity switch is moved into the second pin position. The same can apply if the detector is designed as a contact switch. This is because the relative movement of the pin away from the contact switch also moves the latter into the second switching position.In principle, it is possible for the detector to also be designed by a different type of detector which is designed for the direct or indirect detection of the predetermined pin position.

[0018] A further advantageous embodiment of the motion detector is characterized by the fact that the pin is formed integrally with the mounting section of the head unit. This ensures that if the head unit is tampered with, the pin executes a movement that corresponds to the movement of the mounting section of the head unit when the corresponding tampering is carried out on the motion detector. If the mounting section is separated from the base unit due to tampering, this is detected by the detector.

[0019] A further advantageous embodiment of the motion detector is characterized in that the base unit has a recess which is arranged and designed such that the pin dips into the recess when the head unit is fastened to the base unit in the predetermined fastening position, wherein the detector is arranged at a bottom portion of the recess. The recess can be designed as a bushing or groove. The detector is arranged at the bottom of the recess such that it preferably only detects the pin in the predetermined fastening position when the pin dips into the recess all the way to the bottom when the head unit is in the predetermined fastening position. If the head unit is not in the predetermined fastening position, i.e. in the tamper position, the pin does not extend completely into the recess all the way to the bottom, but possibly only partially or not at all.In this case, the pin is not detected by the sensor, so that the sensor signal generated by the sensor at least indirectly represents the tamper position of the head unit. The recess in the base unit is preferably formed on the front of the base unit, which is opposite the back of the head unit, in particular the back of the fastening section of the head unit. The recess in the base unit makes it particularly simple and effective to prevent the detector from being tampered with by any other means, so that the detector cannot be fooled into thinking that the pin is acting on the detector. If, for example, a screwdriver is inserted laterally between the head unit and the base unit in order to tamper with the detector, this tampering is at least essentially impossible if the detector is arranged at the bottom of the recess.The screwdriver doesn't protrude into the recess, ensuring particularly secure tamper protection for the motion detector.

[0020] A further advantageous embodiment of the motion detector is characterized in that the first connection is arranged on the rear side of the mounting section of the head unit, while the second connection is arranged on the front side of the base unit. In particular, the first and second connections are arranged such that a signal connection is established when the head unit is connected to the base unit in the predetermined mounting position.

[0021] According to the invention, the first connector and the second connector are designed as plug-in connectors that engage one another when the head unit is moved into the predetermined mounting position to establish the connection to the base unit. This also makes it particularly easy to ensure a detachable connection between the first and second connectors.

[0022] A further advantageous design of the motion detector is characterized by the fact that the sensor head is pivotably mounted relative to the mounting section of the head unit. This allows the detection range to be adjusted particularly easily.

[0023] According to a second aspect of the invention, the object mentioned above is achieved by a system having the features of claim 12. Thus, a system is provided which has a motion detector, wherein the motion detector is designed according to the first aspect of the invention and / or one of the associated advantageous embodiments. The system also has an electric lamp. The electric lamp is coupled to the switch of the base unit such that an electrical power supply to the lamp is controlled via the switch. The switch is preferably the switch of the motion detector, which is switched by the evaluation unit when the detector signal represents the sabotage position.The power supply to the lamp can therefore be controlled via the switch, so that the lamp is only supplied with electrical power when the switch is switched on, and the transmission of electrical power to the lamp is interrupted when the switch is not switched on. With regard to the motion detector of the system, reference is made analogously to the advantageous explanations, preferred features, effects, and / or advantages as explained in connection with the motion detector according to the first aspect of the invention and / or one of the associated advantageous embodiments. A repetition is therefore omitted. It should be noted, however, that the system can have multiple motion detectors. Each of the motion detectors can be designed according to the first aspect of the invention and / or one of the associated advantageous embodiments. An electric lamp can be provided for each motion detector.However, it is also possible for each or more of the motion detectors to be coupled via the associated switches to control the same electrical power supply to the lamp.

[0024] Further features, advantages, and possible applications of the present invention will become apparent from the following description of the exemplary embodiments and the figures. All described and / or illustrated features, individually and in any combination, constitute the subject matter of the invention, regardless of their composition in the individual claims or their references. In the figures, the same reference numerals continue to represent the same or similar objects. Figure 1 shows an advantageous embodiment of the motion detector in a schematic view with a head unit in a mounting position. Figure 2 shows the motion detector from Figure 1 with the head unit in a tamper position.

[0025] In the Figure 1An advantageous embodiment of the motion detector 2 is shown in a schematic view. The motion detector 2 has a base unit 4 and a head unit 6. The head unit 6 has a sensor 8, which is designed for the contactless detection of a detection area 10. The head unit 6 preferably comprises a fastening section 28 and a sensor head 26, wherein the sensor head 26 is preferably connected to the fastening section 28 via a joint. The joint allows the sensor head 26 to be pivoted. The sensor 8 is fastened to the sensor head 26. The sensor 8 is arranged under a protective dome 46 of the sensor head 26, wherein the protective dome 46 is preferably permeable to infrared radiation. This is particularly advantageous when the sensor 8 is designed as a PIR sensor, i.e. as a pyroelectric sensor. The detection area 10 is the area that can be detected by the sensor 8 without contact.If an object with a certain temperature moves within the detection area 10, this leads to a corresponding detection by the sensor 8, which in turn is designed to generate a sensor signal representing the temperature of the detected object. In particular, the sensor 8 can generate the sensor signal such that the sensor signal represents the temperature or the temperature change in the detection area 10 and thus in particular of the moving object. The sensor head 26 and the fastening section 28 can each have a housing, which is preferably made of plastic. The head unit 6 comprises the sensor head 26 and the fastening section 28. The fastening section 28 can also be referred to as the fastening part of the head unit 6.

[0026] The head unit 6 also has a first connection 12. This can be an electrical connection, in particular an electrical plug connection. The first connection 12 can be designed in the manner of a plug. Furthermore, it is preferably provided that a first signal line 48 is provided, which couples the sensor 8 to the first connection 12, so that the signal generated by the sensor 8 can be transmitted to the first connection 12 via the first sensor line 48.

[0027] The base unit 4 of the motion detector 2 has a second connection 16 and an evaluation unit 14. The second connection 16 can be designed as an electrical connection, in particular as an electrical plug connection. In particular, the second connection 16 can be designed as a socket 16. The second connection 16 is coupled to the evaluation unit 14 via a second signal line 50. A signal can be transmitted from the second connection 16 to the evaluation unit 14 via the second signal line 50.

[0028] In the Figure 1The motion detector 2 is shown in the regular assembly state or delivery state. The head unit 6 is fastened to the base unit 4 in a force-fitting and / or form-fitting manner in a predetermined fastening position, so that the first connection 12 is detachably connected to the second connection 16 in order to be able to transmit the sensor signal from the sensor 8 to the evaluation unit 14. In the predetermined fastening position 18, the head unit 6 and the base unit 4 are arranged relative to one another in such a way that the first connection 12 and the second connection 16 are detachably connected, engage one another, or establish electrical contact with one another through other principles, thereby forming a connection that serves to transmit the sensor signal from the sensor 8 to the evaluation unit 14. The head unit 6 can be fastened to the base unit 4 by fastening means which are provided in Figure 1are not shown. For example, the head unit 6 can be screwed to the base unit 4 by means of screws. Alternatively or additionally, it can be provided that the head unit 6 has an adjusting pin 42 on the rear side 30 of the fastening section 28, which is designed and / or intended to engage in an adjusting groove 44 on the front side 32 of the base unit 4 in order to ensure precise positioning of the head unit 6 relative to the base unit 4 when the head unit 6 is to assume the predetermined fastening position 18 on the base unit 4. By means of the adjusting pin 42 and the adjusting groove 44, a positive connection between the head unit 6 and the base unit 4 can be ensured. In addition, screws can be used to create a force-fitting connection between the head unit 6 and the base unit 4.However, the use of the adjustment pin 42 and the adjustment groove 44 is not mandatory. The use of screws is also not mandatory. For example, locking lugs and locking grooves can be formed on the rear side 30 of the fastening section 28 of the head unit 6 and on the base unit 4, which are designed such that a force-fitting and form-fitting connection can be established between the head unit 6 and the base unit 4, so that when the locking lugs engage in the locking grooves, the predetermined position of the head unit 6 on the base unit 4 is ensured. Particularly preferably, the first and second connectors 12, 16 are arranged opposite one another in the predetermined fastening position 18.Due to the electrical connection created by the connection between the first and second terminals 12, 16, the sensor signal can be transmitted from the sensor 8 to the evaluation unit 14 via the first signal line 48, the two terminals 12, 16 and the second signal line 50.

[0029] The evaluation unit 14 is preferably designed to detect movement in the detection area 10 based on the sensor signal from the sensor 8. Furthermore, the evaluation unit 14 is preferably designed to switch the switch 24 of the base unit 4 when the evaluation unit 14 detects movement in the detection area 10. The switch 24 forms part of the base unit 4. The switch 24 can be connected to a third terminal 52 via a line connection 54 in order to switch an electrical circuit between two connection pins of the third terminal 52. The switch 24 can be designed as a semiconductor switch, in particular a MOSFET, or as a relay.

[0030] The use of the motion detector 2 is often used to detect a movement in the detection area 10 and to signal this movement via this switch 24 to a monitoring unit, which initiates follow-up measures based on this signal.

[0031] In practice, it has been found that in order to conceal movement in the detection area 10, sabotage of the motion detector 2 can occur, whereby the sensor 8 is forcibly separated or torn off from the motion detector 2. If the sensor 8 is separated, no detection of movement in the detection area 10 can take place. Against this background, the Figures 1 and 2The motion detector 2 shown is preferably designed such that the connection between the base unit 4 and the head unit 6 is configured such that it forms a predetermined breaking point when a tensile or transverse force acts on the head unit 6. If, for example, an attempt is made to tear the sensor 8 off from the rest of the motion detector 2 by pulling on the sensor head 26, the predetermined breaking point formed by the connection between the head unit 6 and the base unit 4 breaks open, so that the entire head unit 6 is separated from the base unit 4 when the sensor head 26 is pulled. Although the electrical connection between the first connection 12 and the second connection 16 is also severed, the motion detector 2 has a detector 20 which serves to detect when the head unit 6 is not in the predetermined fastening position 18, as shown in the Figure 1is shown. If the head unit 6 is completely or partially separated from the base unit 4, this position is referred to as a tamper position 22. The detector 20 forms part of the base unit 4 and is preferably arranged in a housing 56 of the base unit 4. The detector 20 can be designed, for example, as a contact switch or as a proximity switch. The detector 20 is arranged and designed to detect whether the head unit 6 is either fastened in the predetermined fastening position 18 to the base unit 4 or in a tamper position 22 deviating from the predetermined fastening position 18. The tamper position 22 is shown by way of example in the Figure 2reproduced. If the detector 20 is designed as a proximity switch, it can detect whether the head unit 6 is fastened in the fastening position 18 to the base unit 4 based on the distance to the rear side 30 of the fastening section 28 of the head unit 6. If the distance between the detector 20 and the rear side 30 exceeds, for example, a predetermined threshold value, this can trigger the detector 20 and thus lead to the detection of the tamper position 22 of the head unit 6. If, on the other hand, the distance between the rear side 30 and the sensor 8 is equal to or less than the predetermined threshold value, this can also be detected by the detector 20 and detected as the predetermined fastening position 18 of the base unit 4. The detector 20 is designed to generate a detector signal that represents whether the head unit 6 is either in the predetermined fastening position 18 or in the tamper position 22.In addition, the detector 20 is coupled to the evaluation unit 14. The detector 20 can be coupled to the evaluation unit 14, for example, via a third signal line 58 in order to transmit the detector signal from the detector 20 to the evaluation unit 14. The evaluation unit 14 is designed to switch the switch 24 of the base unit 4 when the detector signal represents the tamper position 22. The evaluation unit 14 can therefore switch the switch 24, for example, when the detector signal represents the tamper position or when the evaluation unit 14 detects movement in the detection area 10 based on the sensor signal. However, the mere fact that the detector signal represents the predetermined fastening position 18 does not lead to the switching of the switch 24. The evaluation unit 14 can be designed accordingly for this purpose. The evaluation unit 14 can be coupled to the switch 24 via a control line 60 in order to control the switch 24.For example, the evaluation unit 14 can control the switch 24, which is designed as a semiconductor switch or as a relay, via the control line 60.

[0032] It has proven particularly advantageous if the detector 20 is arranged on a bottom section 40 of a recess 38 which is recessed relative to the front side 32 of the base unit 4. This is because sabotage often occurs using hand tools such as a screwdriver. In the event of sabotage, this screwdriver can be inserted laterally between the base unit 4 and the head unit 6 in order to separate the head unit 6 from the base unit 4. Attempts can be made to tamper with the detector 20. However, this tampering is made significantly more difficult if the detector 20 is on the bottom section 40 of the recess 38. This is because it is preferably provided that a pin 34 of the head unit 6 is formed and arranged on the rear side 30 of the fastening section 28, so that the pin 34 can only be in a predetermined pin position 36, as is exemplified in the Figure 1is shown schematically, acts on the detector 20 when the head unit 6 is fastened to the base unit 4 in the predetermined fastening position 18, so that the detector 20 is designed to detect the predetermined fastening position 18 or the tamper position 22 via the action of the pin 34 on the detector 20. In particular, the recess 38 and the pin 34 can be designed such that a screwdriver pushed laterally between the head unit 6 and the base unit 4 cannot engage in the recess 38 in order to trigger the detector 20. This applies in particular if the detector 20 is designed as a contact switch that can be switched via the pin 34. Thus, the length of the pin 34 can be designed such that the pin 34 switches the detector 20, designed as a contact switch, only when the pin 34 is in the predetermined pin position 36 orthe head unit 6 is in the predetermined fastening position 18.

[0033] For the sake of completeness, it should be mentioned that the base unit 4 is designed to be fastened to a wall, a ceiling or another fixed object. For example, the housing 56 of the base unit 4 can have fastening openings through which screws can be passed in order to fasten the base unit 4 to a wall, a ceiling and / or to the aforementioned fixed object. The switch 24 can serve as a switch for controlling electrical energy from an electrical power supply to a lamp via the line connection 54 and the third terminal 52. For example, the switch 24 can be used to close an electrical circuit of the lamp with the electrical power supply so that electrical current flows through the lamp, which in turn emits light.However, it is also possible for the switch 24 to be coupled via the line connection 54 and the third connection 52 to a monitoring unit, which is informed via the switching of the switch 24 as to whether or not sabotage has occurred on the motion detector 2.

[0034] Additionally, it should be noted that "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude a plurality. Furthermore, it should be noted that features described with reference to one of the above embodiments can also be used in combination with other features of other embodiments described above. Reference signs in the claims are not to be considered as limitations. List of reference symbols

[0035] 2 Motion detector 4 Base unit 6 Head unit 8 Sensor 10 Detection area 12 First connection 14 Evaluation unit 16 Second connection 18 Mounting position 20 Detector 22 Tamper position 24 Switch 26 Sensor head 28 Mounting section 30 Rear (of the mounting section) 32 Front (of the base unit) 34 Pin 36 Pin position 38 Recess 40 Base section 42 Adjustment pin 44 Adjustment groove 46 Protective dome 48 First sensor line 50 Second signal line 52 Third connection 54 Cable connection 56 Housing 58 Third signal line 60 Control line

Claims

1. A motion detector (2) comprising a base unit (4) and a head unit (6), wherein the head unit (6) comprises a sensor (8) that is configured to detect a detection area (10) in a contactless manner and to generate a sensor signal based thereon, wherein the sensor (8) is coupled to a first connection (12) of the head unit (6), wherein the base unit (4) comprises an evaluation unit (14) that is coupled to a second connection (16) of the base unit (4), wherein the head unit (6) is fastened to the base unit (4) in a predetermined fastening position (18) in a force-fit and / or form-fit manner, so that the first connection (12) is detachably connected to the second connection (16), in order to transmit the sensor signal from the sensor (8) to the evaluation unit (14), wherein the base unit (4) comprises a detector (20) which is arranged and configured in such a manner to detect whether the head unit (6) is either fastened to the base unit (4) in the predetermined fastening position (18) or is in a sabotage position (22) differing from the predetermined fastening position (18), wherein the detector (20) is configured to generate a detector signal that represents whether the head unit (6) is either in the fastening position (18) or in the sabotage position (22), wherein the detector (20) is coupled to the evaluation unit (14), in order to transmit the detector signal to the evaluation unit (14), wherein the evaluation unit (14) is configured to actuate a switch (24), in particular a semiconductor switch or a relay, of the base unit (4) when the detector signal represents the sabotage position (22) and wherein the first connection (12) and the second connection (16) are formed as plug-in connection means that engage with one another when the head unit (6) is brought into the predetermined fastening position (18), in order to establish the connection to the base unit (4).

2. The motion detector (2) according to the preceding claim, characterized in that the sensor (8) is configured to detect a change in a temperature of an object in the detection area (10) and / or a movement of the object in the detection area (10), so that the sensor signal represents the temperature of the object and / or the detected movement of the object.

3. The motion detector (2) according to any one of the preceding claims, characterized in that the evaluation unit (14) is configured to detect a movement in the detection area (10) based on the sensor signal, and wherein the evaluation unit (14) is configured to actuate the switch (24) when a movement is detected in the detection area (10) by the evaluation unit (14).

4. The motion detector (2) according to any one of the preceding claims, characterized in that the detector (20) is formed as a contact switch or as a proximity switch.

5. The motion detector (2) according to any one of the preceding claims, characterized in that the sensor (8) is arranged in a sensor head (26) of the head unit (6), wherein the sensor head (26) is fastened to a fastening section (28) of the head unit (6), and wherein the fastening section (28) is fastened with an associated rear side (30) in a force-fit and / or form-fit manner to a front side (32) of the base unit (4).

6. The motion detector (2) according to the preceding claim, characterized in that a pin (34) of the head unit (6) is formed and arranged on the rear side (30) of the fastening section (28), so that the pin (34) acts on the detector (20) only when it is in a predetermined pin position (36), which occurs only when the head unit (6) is fastened in the predetermined fastening position (18) to the base unit (4), so that the detector (20) is configured to detect either the predetermined fastening position (18) or the sabotage position (22) based on the action of the pin (34) on the detector (20).

7. The motion detector (2) according to the preceding claim, characterized in that the pin (34) is formed integrally with the fastening section (28) of the head unit (6).

8. The motion detector (2) according to any one of the preceding claims 7 to 8, characterized in that the base unit (4) comprises a recess (38) which is arranged and formed, so that the pin (34) plunges into the recess (38) when the head unit (6) is fastened to the base unit (4) in the predetermined fastening position (18), and wherein the detector (20) is arranged in a bottom section (40) of the recess (38).

9. The motion detector (2) according to any one of the preceding claims 6 to 9, characterized in that the first connection (12) is arranged on the rear side (30) of the fastening section (28) of the head unit (6), and wherein the second connection (16) is arranged on the front side (32) of the base unit (4).

10. The motion detector (2) according to any one of the preceding claims 6 to 10, characterized in that the sensor head (26) is pivotably fastened relative to the fastening section (28) of the head unit (6).

11. A system, comprising a motion detector (2) according to any one of the preceding claims and an electric lamp, wherein the lamp is coupled to the switch (24) of the base unit (4) in such a manner that an electrical power supply to the lamp is controlled via the switch (24).