WO2024068033A1

WO2024068033A1 - Detector for detecting presence or motion in a security installation

Info

Publication number: WO2024068033A1
Application number: PCT/EP2022/087990
Authority: WO
Original assignee: Verisure Sàrl
Priority date: 2022-09-29
Filing date: 2022-12-29
Publication date: 2024-04-04

Abstract

Provided is a detector (114) for detecting presence or motion in a security installation, the detector (114) having at least one sensor (706) for detecting thermal radiation, the detector (114) having a detection range adjustment device

Description

Detector for detecting presence or motion in a security installation

Technical field

The present invention relates to a detector for detecting presence or motion in a security installation to secure at least part of a perimeter of premises and to monitor premises.

Background

Security installations that are or include security monitoring systems for monitoring premises, often referred to as alarm systems, typically provide a means for detecting the presence and/or actions of people at the premises, and reacting to detected events. Commonly such systems include sensors to detect the opening and closing of doors and windows to provide a secure perimeter to the premises, creating one or more protected interior spaces, movement detectors to monitor spaces (both within and outside buildings) for signs of movement, microphones to detect sounds such as breaking glass, and image sensors to capture still or moving images of monitored zones.

Such systems may be self-contained, with alarm indicators such as sirens and flashing lights that may be activated in the event of an alarm condition being detected. Such installations typically include a control unit (which may also be termed a central unit), generally mains powered, that is coupled to the sensors, detectors, cameras, etc. (“nodes”), and which processes received notifications and determines a response.

The central unit may be linked to the various nodes by wires, but increasingly is instead linked wirelessly, rather than by wires, since this facilitates installation and may also provide some safeguards against sensors/detectors effectively being disabled by disconnecting them from the central unit. Similarly, for ease of installation and to improve security, the nodes of such systems typically include an autonomous power source, such as a battery power supply, rather than being mains powered. As an alternative to self-contained systems, a security monitoring system may include an installation at a premises, domestic or commercial, that is linked to a remote Central Monitoring Station (CMS) where, typically, human operators manage the responses required by different alarm and notification types.

In such centrally monitored systems, the central unit at the premises installation typically processes notifications received from the nodes in the installation, and notifies the Central Monitoring Station of only some of these, depending upon the settings of the system and the nature of the detected events. In such a configuration, the central unit at the installation is effectively acting as a gateway between the nodes and the Central Monitoring Station. Again, in such installations the central unit may be linked by wires, or wirelessly, to the various nodes of the installation, and these nodes will typically be battery rather than mains powered.

Such security monitoring systems contribute to the safety and wellbeing of occupants of the protected premises, as well as safeguarding articles within the protected perimeter - which may of course not simply be limited to a house or dwelling, but may also extend to the grounds of the house, protected by a boundary fence and gate, for example.

A detector, usually a PIR, is used to detect motion near the camera, and activate the camera to capture image frames and/or a video clip and/or a live stream. PIR’s are very energy efficient, and inexpensive, so very convenient to use. The remainder of the device can be in a dormant mode until woken up by a signal from the PIR. This is particularly relevant for each and every component of the security installation which is powered by batteries.

However, such detectors often result in false positive detections. One reason is that the range is very difficult to control. It is possible to adjust the sensitivity of the PIR threshold. This is range dependent, but also affects other parameters, and can comprise performance. False positives can consume power unnecessarily (limiting battery life for battery operated devices), and generate a large number of false-positive potential security events.

The object of the invention is to reduce false positive detections.

Summary of the invention The invention is applicable to any such camera, but especially to access devices and/or video doorbells, which may have a wide variety of intended detection ranges, which could be from relatively close to relatively far. The same device should be installable in multiple ways. For example, when installed with a field of view on one’s own property, it may be desired to detect motion even far away. However, external facing devices, which may face out of the user’s own property into public space, may be problematic for many conventional detectors, and may be triggered by motion in the public space.

The invention relates to security devices that include a thermal detector. Devices can include cameras, any security device including a camera, and video doorbells.

Generally speaking, a first approach to reduce false triggering by movement outside of the desired range, is to provide a device for limiting the range of the detector. This ensures that no triggering occurs by movement outside the area of interest. As a simple example, a detector associated with a camera at an entrance door close to a public street should have a range of detection which does not cover the street in order to avoid that any person passing the detection range potentially triggers the detector.

An adjustment of the range of the detector can be made mechanically, by the use of suitable optics, or by choosing a suitable sensor out of a plurality of sensors provided within the detector. The multiple sensors can have different ranges and/or different fields of view angles (could be horizontal and/or vertical), with one sensor being for a close range and the other for longer ranges. Depending on the signal evaluation to be made, the control processing the detection signal can choose one sensor, the other sensor, or both sensors.

A second approach to reduce false triggering by movement outside of the desired range is to selectively mask the undesired areas for thermal radiation so that any movement there cannot be seen by the detector. For masking certain areas of the viewing field of the detector, a screen could be placed between the optics and sensor, or in front of the sensor, or even in front of the optics, or integrated into the optics. Electronic control can avoid the need for a technician to make manual mechanical adjustments. The advantage of this approach is that the same sensor can be used throughout a product line, and the customization takes place in a very effective manner as regards both costs and effort of installation.

In the prior art a conventional PIR (passive infrared sensor) optic includes multiple cells or zones acting as a Fresnel lens, mapping different spatial zones on to the same PIR area. By selectively masking one or more zones, or a region of zones, the range can be reduced without changing the optic itself. Zones could be masked to provide horizontal range limiting and/or vertical range limiting, or to tailor the range different from the optic.

The invention provides a detector for detecting presence or motion in a security installation, the detector having at least one sensor for detecting radiation, the detector having a detection range adjustment device (DRAD). The DRAD allows customizing the detector to the particular operating conditions with little effort. “Operating conditions” are mostly the geometrical conditions at the site where the detector is installed, namely the area within which detection shall take place, and conversely the area where no detection shall take place in order to avoid false positives.

The DRAD can be mechanical which has the advantage of low manufacturing costs and high reliability.

It is possible to use special optics in front of the sensor to limit the range, and/or horizontal and/or vertical field of view. As an alternative to an optics, a cover can be used, in particular for a video doorbell that is quite accessible during the installation process.

A first example of a mechanical DRAD is a specific optics chosen from a set of predefined optics, or a specific cover chosen from a set of predefined covers. The detector is delivered to the user or the installation personnel with a set of predefined optics or covers which allow customizing the range and/or the field of view of the detector to the particular situation very conveniently.

A second example of a mechanical DRAD is an adjustable mounting structure for mounting the sensor within a detector housing so as to be tiltable. The detector as such is mounted in a predefined position, and only the sensor within the detector housing can be adjusted as regards his position so as to customize his range and field of view. This is advantageous as there is no risk that the orientation of the sensor becomes changed once the installation has been completed as the sensor is protected with the housing of the detector.

The sensor of the detector can be mounted on a mechanically tiltable mounting structure, e.g. an internal mount structure inside housing. The installation technician can adjust the mount, optionally between one or more predetermined positions, or just continuously variably, to suit the installation. Tilting could be in the vertical direction to limit range absolutely, and/or horizontal to skew the field- of-view off axis, also limiting the range horizontally.

The above mount could also be electrically adjustable, horizontally and/or vertically, similar to electrically adjustable car-door mirrors or electrically adjustable car-headlight mounts.

The mounting structure can be adapted for orienting the sensor in one of several predefined positions, making the installation process very simple in that the position that fits the best has to be chosen. The mounting structure can have a ratchet mechanism or a spring-loaded detent mechanism for conveniently locking the sensor in one of the predefined positions.

Alternatively, the mounting structure can be adapted for orienting the sensor in one of an infinite number of continuously variable positions. This allows orienting the sensor in a very precise manner so that the range and/or field of view can be adapted to the particular installation conditions in an optimum manner.

The mounting structure can comprise a mechanical locking means for locking the sensor in an adjusted position, such as a screw, a clamp of similar device. A mechanical locking means results in low manufacturing costs and a simple installation process.

The mounting structure can comprise an electrically operated adjustment mechanism so that the range and/or field of view can very conveniently be adjusted after the detector has been mounted at the desired location. Direct access to the sensor is not necessary for making the desired adjustments so that a once chosen position can very conveniently be corrected later if it turns out that the detection behavior is not as expected. The DRAD can also comprise a screen for masking from the field of view of the sensor those areas which could potentially lead to false positive detection and/or which are irrelevant regarding the desired detection.

The screen can be placed between the optics and sensor, or in front of the sensor, or even in front of the optics, or integrated into the optics. Electronic control can avoid the need for a technician to make manual mechanical adjustments.

The screen can be opaque (at least for infrared radiation) and be mounted with the detector housing in one of a plurality of positions so as to limit the field of view of the sensor in the desired manner.

In an alternative, the transmittance of the screen can be configurable. In this embodiment, the screen is mounted within the detector housing in one predetermined position, and the range and/or field of view is customized by selectively changing the transmittance in certain portions of the screen as compared to other portions of the screen.

In other words, the screen is made opaque in certain areas so as to prevent detection of radiation in areas of the detection range “behind” the opaque areas, and left with a high transmittance in those areas which are between the sensor and the range in which detection shall be made.

The screen can comprise electronic paper (e-paper) which is readily available and has a very low power consumption. Further, the areas to be masked can be very conveniently be set in the desired manner. The electronic paper does not necessarily be conventional black-white, but can have controlled transparency.

A simulation program can be used by installation personnel for appropriately configuring the screen. The simulation program can use an image of the surrounding of the detector taken by a camera from the position of the detector, and the installation personnel can mark on the image which areas shall not be considered by the detector. The screen is then configured appropriately. Once configured, the energy consumption of the screen is very low as the masked areas to not have to change, and the screen can have a low refresh rate.

As an alternative to changing the transmittance of the screen, a material can be used which has a reflectivity that can be configured so as to customize the detection area of the detector. The screen has a controlled pixel reflectivity (e.g. black-white or a controlled reflection direction to reflect on to, or away from, the PIR element.

As an alternative to a screen, a collimator can be used.

The DRAD can comprise a MEMS (microelectromechanical system) for customizing the detection area in accordance with particular requirements of the respective installation situation.

The MEMS can be a micro-mirror or a micro-lens array for customizing the viewing area of the detector to the particular needs in a specific installation space.

The DRAD can optionally include DLP (digital light processing) technology for electro-mechanically controlling the transmittance and/or reflectivity selectively in one or more zones (e.g. pixels) in response to an electronic control signal.

The MEMS can also be used to transmit the radiation to one of a plurality of sensors within the detector, or to more than one sensor of a group of sensors arranged within the detector. The different sensors can have different viewing angles and/or ranges, different sensitivities, and/or be assigned to different radiations.

It is also possible to use an LCD display as the DRAD. The LCD display can be transparent so as to act in the manner of a screen by changing the transmittance of certain areas which are changed to black. With a view to the power consumption, the refresh rate of the LCD display is chosen to be as low as possible.

The DRAD can be used for both adjusting the vertical detection range and the horizontal detection range so that the detector is “blind” in areas which are not relevant in view of the security requirements of the security installation.

The DRAD can operate electronically which simplifies the installation process. In a manner similar to the configuration of a screen, the installation process can be assisted by a simulation program so that the configuration process can be reduced to marking on an image of the surroundings of the detector those areas where detection shall take place, or those areas which shall be disregarded by the detector. An electronic DRAD also allows to change the viewing angle and/or range in accordance with predefined patterns or with patterns that involve a self-learning algorithm. As a simple example, a detector mounted such that his maximum range covers a public street might use the DRAD to limit the detecting range so as to exclude the public street during daytime when there is much traffic on the street, taking into account that critical incidents are very unlikely as long as there is much traffic on the street. During nighttime when the street is deserted, the viewing range can be made larger to be able to detect critical approaches to the monitored premises earlier, allowing for more response time. The change from one pattern to the other can be made dependent on time or available daylight, or can be made by an algorithm which learns (with Al) when many uncritical events are captured by the detector and what change to the viewing angle and/or detection range should be made to achieve a good compromise between long battery lifetime and reliable detection of critical incidents.

The detector can comprise multiple sensors which are different from each other with respect to at least one of field of view angle and viewing range. The DRAD allows choosing from the plurality of sensors the one which provides the best detection quality.

The sensor(s) used in the detector can in particular be a passive IR sensor (PIR) which is advantageous in that it is based on well-established technology and is available at low costs.

The PIR can be a multi-channel PIR which generates multi-channel signals from PIR elements that are intermixed or interdigitated in the same array. A multichannel PIR can generate a more feature-rich output which ultimately can result in a more reliable evaluation of the processed signal.

As an alternative to a PIR sensor, it is possible to use a TMOS sensor to detect the radiation. It is also possible to use multiple sensors with one or more sensors being PIRs and one or more sensors being TMOS sensors.

The DRAD can comprise at least one electro-mechanically tiltable disc and/or dot and/or other pixel element, (optionally an array of plural elements) for achieving the desired customization of the viewing angle and/or the range. The sensor generates at least one output signal responsive to radiation incident on the sensor, the number of output signals defining an image resolution of the sensor, and wherein the number of output signals is less than five, optionally less than four, optionally less than three, optionally less than two. In other words, the output of the sensor(s) is quite low in in terms of information content or bandwidth. The sensor thus has a very low power consumption as compared to a high- resolution sensor.

The detector of the invention can comprise optics configured to map radiation from a plurality of different source zones into overlapping areas sensed by the sensor, thereby increasing the signal quality and allowing a better evaluation of the provided signal. “Better evaluation” here means that the recognition rate of a critical situation is better and the rate of false positives is lower.

A further closely related aspect of the invention provides a method comprising: a) providing a device for a security installation, the device optionally including any of the features described above, the device comprising at least one thermal radiation sensor; and b) adjusting a setting of the device to set a field of view of the sensor to correspond to a desired monitoring area and/or monitoring range, with respect to the device.

The step of adjusting may optionally include (i) mechanically adjusting the device to set the field of view and/or (ii) electronically adjusting the device to set the field of view.

Description of figures

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic drawing showing a front elevation of stylised building with an external space which is monitored by a security monitoring system according to an embodiment of the invention;

Figure 2 is a schematic part plan view of premises protected by a security monitoring system, together with other elements of the system; Figure 3 shows schematically an architecture including a security monitoring system, a video entry arrangement, and an electrically controlled lock;

Figure 4 is a schematic block diagram of a video entry arrangement;

Figure 5 is a schematic top view of part of the building shown in Figure 1 with the detector used for capturing radiation in an area in front of the entrance door of the building;

Figure 6 is a schematic view of a detector according to a first embodiment;

Figure 7 is a schematic view of a detector according to a second embodiment;

Figure 8 is a schematic view of a detector according to a third embodiment;

Figure 9 is a schematic view of a detector according to a fourth embodiment;

Figure 10 is a schematic view of a detector according to a fifth embodiment;

Figure 11 is a schematic view of a screen used in the detector of Figure 10;

Figure 12 is a schematic view of a detector according to a sixth embodiment; and

Figure 13 is a schematic view of a detector according to a seventh embodiment.

Specific description

Figure 1 shows a view of the front of a premises 100 protected by a security monitoring system according to an aspect of the present invention. The premises, here in the form of a house, have an exterior door, here front door, 102. The door gives access to a protected interior space. The security monitoring system secures at least part of a perimeter to the premises 100, and the door constitutes an exterior closure 102 in the secure perimeter giving access to a protected interior space 200 of the premises. A lock 104 on the exterior door is optionally electrically controlled so that it can be locked and unlocked remotely.

To the side of the door, on the fagade of the house, is a first video camera in the form of a video doorbell 106 which looks out from the fagade of the premises so that anyone approaching the door along the path 108 can be seen, and in particular when a visitor stands at the door their face should clearly be visible. The video doorbell includes an actuator, e.g. a push button, for a visitor to indicate their presence at the closure. The video doorbell also includes an audio interface to enable bidirectional audio communication with a visitor at the closure 102.

As is conventional, the video doorbell preferably includes an infrared light source to illuminate whatever is in front of the video doorbell. Optionally, as shown, the fagade of the house also carries an external keypad 110 by means of which a user can disarm the security monitoring system, and unlock the lock 104. Also shown is an optional second video camera 112 which is coupled to a presence and/or movement detector 114. The detector may optionally be a thermal detector, for example a PIR sensor. The second video camera 112 may be arranged when the security monitoring system is armed, to capture video of the front of the house and the private area, e.g. the garden, in front of the house and signal an alarm event to a controller of the security monitoring system. As with the doorbell camera, the second video camera is preferably provided with an audio interface 116 to enable bidirectional audio communication with anyone observed by the second video camera. Although the first video camera is illustrated in the form of a video doorbell, the first video camera may additionally or alternatively have the features described above for the second video camera, whether or not plural video cameras are used.

Figure 2 is a schematic part plan view of a premises 100 protected by security monitoring system according to an aspect of the invention, together with other elements of the system, corresponding generally to the premises of Figure 1. The front door 102, with electrically controlled lock 104, leads into the protected interior space 200 of the premises. Each of the windows 202 and the rear door 204 is fitted with a sensor 206 to detect when they are opened. Each of the sensors 206 includes a radio transceiver to report events to a controller, or central unit, 208 of the security monitoring system. If one of the sensors 206 is triggered when the system is armed, a signal is sent to the central unit 208 which in turn may signal an alarm event to a remote central monitoring station 210. The central unit 208 is connected to the remote central monitoring station 210 via the Internet 212, either via a wired or a wireless connection. Also wirelessly coupled to the central unit 208 are the video doorbell 106, the electrically controlled lock 104, and if present the second video camera 112, its associated presence and/or movement detector 114 (although the latter may be integral with the second video camera 112) and the audio interface 116. These items, and the sensors 206, are preferably coupled to the central unit 208 using transceivers operating in the industrial scientific and medical (ISM) bandwidths, for example a sub-gigahertz bandwidth such as 868 MHz, and the communications are encrypted preferably using shared secret keys. The security monitoring system may also include other sensors within the protected interior space, such as an interior video camera 214 and associated movement detector 216 (which again may be integral with the camera 214), and each of the interior doors 218 may also be provided with a sensor 206 to detect the opening/closing of the door. Also shown in Figure 2 are a user device 220, preferably loaded with an appropriate app - as will be described later, and a public land mobile network (PLMN) by means of which the central monitoring station 210, and the central unit 208, may communicate with the user device 220.

Operation of the security monitoring system may be controlled by one or more of: the controller 208, the remote monitoring station 210, and a security monitoring app installed on the user device 220. For example, the remote monitoring station 210, if provided, may receive one or more signals from any of the first camera and/or video doorbell 106, the second camera 112, the keypad 110, the sensors 206 and/or 520 (described in more detail later). The remote monitoring station 210 may transmit commands for controlling any one or more of: the arm state of the alarm system (e.g. armed or unarmed); commanding a tripped alarm state to be signalled by the alarm system (e.g. by triggering one or more sirens to generate alarm noise); commanding a lock state of the door lock 104 (e.g. locked or unlocked), commanding operation of one or more functions of the video doorbell 106, commanding operation of one or more cameras to transmit images to the remote monitoring unit. Communication with the remote monitoring station 210 may pass through the controller 208, as described above. In other embodiments without the remote monitoring station 210, or should communication with the remote monitoring station 210 be interrupted, operation of the alarm system may be controlled by the controller 208. In yet other embodiments, the controller 208 may be omitted, and the individual peripheral devices may communicate directly with the remote monitoring station 210.

The security monitoring system app is installed on a user device 220, here shown as a smartphone, although of course it could be almost any kind of electronic device, such as a laptop or desktop computer, a tablet such as an iPad, a smart watch, or even a television.

The security monitoring system may further comprising an audio interface to enable audio communication with a visitor at the closure, the controller 208 being configured to enable the remote monitoring centre 210 to use the audio interface to speak to the visitor.

The security monitoring system preferably further comprises a first video camera arranged to observe a space in front of the exterior of the closure, the controller 208 being configured to enable the remote monitoring centre 210 to use the first video camera to observe the visitor.

Conveniently, the first video camera may be a video doorbell, which is convenient both in terms of the location of the camera, and the co-location of the video and audio interfaces, along with the actuator, and in terms of the visual performance of the camera - as video doorbells are typically very well placed to capture images of people at the door. Conveniently, the video doorbell includes the audio interface, as this is likely to be well located from the point of view of performance, and it may also reduce installation complexity and time.

Preferably, the security monitoring system further comprising a second video camera arranged to observe the protected interior space behind the closure, the controller being configured to enable the remote monitoring centre to use the second video camera to observe any visitor within the protected interior space.

Although use of a doorbell video camera for the purpose of observing the visitor, and the doorbell audio interface as a means to speak with a visitor at the door are preferred, it will be appreciated that the actuator, the external video source, and the external audio interface may all be provided in free-standing components to implement embodiments of the invention. Thus, although it is preferred for the first video camera, if used, to be the video camera of a video doorbell, because of the generally ideal location of such a camera in terms of surveying the space in front of the front door 102, it is also possible to use a different video camera installation, such as that shown as 112, which also observes the space in front of the front door. Unlike most video doorbells, which typically do not show a view of the exterior face of the front door itself, a video camera installation such as that shown schematically in Figures 1 and 2 as 112 may provide a view not only of the space in front of the front door, but also of the door. As previously described, the video camera installation 112 includes, or has an associated, presence and/or motion detector 114, such as a PIR, a TMOS or other thermal sensor, with the camera 112 typically only being turned on when the sensor detects movement and/or a presence within its field of view. It is also possible to make use of a different form of video camera installation, such as a surveillance camera installation. Typically, a surveillance camera installation does not require a movement/presence sensor, rather when the surveillance camera is activated it may continuously monitor the area under surveillance, typically streaming images continuously or every few seconds to a monitoring location. Such a surveillance camera may also operate under the control of a security monitoring system according to an aspect of the invention, the controller 208 of the security monitoring system transmitting a signal to cause the surveillance camera to capture images and transmit the captured images to the controller 208, and to forward the captured images for checking remotely, e.g. at the central monitoring station 210 or at a user device 220.

Alternative embodiments will now be described with reference to Figures 3 and 4. Figure 3 shows schematically an architecture in which a security monitoring system, shown generally as 500, is coupled to a video entry arrangement 510, an electrically controlled lock, such as the lock 104 of Figures 1 and 2, and a remote monitoring station 210. The security monitoring system 500 includes a security monitoring system controller 208, together with a collection of various sensors 520, including an external video camera 112, an internal video camera 214, a closure status sensor 206 for the closure (e.g. door 102) which is locked by electrically controlled lock 104, and an admittance zone sensor 216 - an example of which is the motion sensor 216 shown in Figure 2, but more generally this is a sensor of any form to detect presence within a zone to which a visitor such as a delivery person, or the like, may be admitted.

Figure 4 is a schematic block diagram of a video entry arrangement 510, such as that shown in Figure 3. Conveniently, the video entry arrangement 510 may take the form of a video doorbell. The video entry arrangement 510 includes a video entry arrangement controller, 600, including a processor 602, and a memory 604, which controls operation of the video entry arrangement - in necessary in association with the central unit 208 (if present) and/or the central monitoring station 210 if present and contactable. An RF transceiver606 is provided for communication with the central unit 208 (if present), and/or the central monitoring station 210, and optionally with other nodes of the security monitoring system (for example an electronic door lock if fitted). The video entry arrangement 510 also preferably includes a power supply unit which may be mains powered, or D.C. powered from an external source (which itself may be mains powered), and which preferably includes at least battery backup but may be only battery powered. Also provided are an audio interface 610, preferably comprising both an input device 612, and an output device 614, a video camera, 620, and an actuator, or bell push, 630, all of which are operatively coupled to the controller 600.

Figure 5 is a top view of part of the premise/building 100 with front door 102 and presence and/or movement detector 114. The path 108 runs towards a public street 109 extending along the premise.

Detector 114 has a constructional viewing angle/detection range which is shown here with dashed lines 700. The detection range extends onto public street 109.

The constructional viewing angle/detection range is the area which the detector is able to cover because of the properties of the sensor used within the detector, and possible limitations because of a housing of the detector within which the sensor is mounted. The constructional viewing angle/detection range is an invariant property of the corresponding type of detector.

With dash-dotted lines 702, a customized, installation-specific detection area is depicted which is different from the constructional viewing angle/detection range of detector 114. The installation-specific detection area can as a maximum be as large/wide as the constructional viewing angle/detection range, but usually is smaller and/or shorter in order to adapt the detection area to the particular requirements. This customization of the detection area is in particular done to prevent false positives and/or unnecessary frequent activation of other elements of the security installation, in particular of a camera which is used to capture an image or video. Detector 114 comprises a detection range adjustment device (DRAD) 704 schematically depicted in Figure 5. Generally speaking the DRAD 704 is adapted for limiting the detection area from the constructional viewing angle/detection range to the customized, installation-specific detection area.

In the example of Figure 5, detector 114 will not detect radiation from sources which are outside the detection area marked by boundary lines 702, despite the fact that detector 114 is able to detect, in his delivery condition, radiation from sources which are within boundary lines 700 (assuming that the maximum distance from detector 114 does not exceed the maximum detection distance for the respective radiation intensity).

In Figure 6, a first example of a DRAD 704 is shown.

Detector 114 here has a sensor 706 mounted within a detector housing 708. DRAD 704 here consists of a mechanical tilting mechanism which allows adjusting the sensor 706 in one of a plurality of predefined positions. Tilting can be made in a vertical direction so as to adjust the detection range, or in a horizontal direction so as to adjust the field of view, or both vertically and horizontally.

A locking mechanism is provided for ensuring that sensor 706 remains in the desired position once the adjustment has been made.

It is important to note that DRAD 704 is inside detector housing 708. Unlike known detectors which can be mounted in different positions so as to achieve some kind of adaptation of their field of view to the particular requirements, detector 114 is adapted for customizing the field of view and the range by changing the position of sensor 706 within detector 114.

In Figure 7, a second example of DRAD 704 is shown. For the elements known from the previous embodiment, the same reference numerals are used, and reference is made to the above comments.

DRAD 704 here comprises an electromechanical drive 710 which allows changing the orientation of the sensor 706 within detector housing 708 so as to customize the field of view and/or the range of detector 114.

Customization of the field of view and/or the detection range of detector 114 can thus be made without having access to the interior of detector housing 708. It is also possible to change the field of view and/or the detection range in accordance with a specific pattern, e.g. for excluding from the field of view and/or from the detection range a path or street which is busy during daytime, but to expand the field of view and/or the detection range onto the path or street during nighttime.

In Figure 8, a third example of DRAD 704 is shown. For the elements known from the previous embodiments, the same reference numerals are used, and reference is made to the above comments.

Here, a cover or shield 712 is arranged within detector housing 708 for blocking or masking part of the field of view and/or the detection range. Thus, sensor 706 is “blind” for part of the maximum the field of view and/or the detection range so that radiation can only be detected within the area designated with lines 702.

Cover/shield 712 can be mounted within detector housing 708 in many different positions so as to customize the field of view and/or the detection range in small steps. Customization can be done in a vertical direction, in a horizontal direction and both horizontally and vertically.

In Figure 9, a fourth example of DRAD 704 is shown. For the elements known from the previous embodiments, the same reference numerals are used, and reference is made to the above comments.

In the fourth example, DRAD 704 consists in a plurality of optics 714 from which an appropriate one (here designated with reference numeral 716) is chosen for being mounted within detector housing 708. Optics 716 customizes the field of view and/or the detection range to the particular mounting situation and detection requirements.

In the shown example, optics 716 limits the field of view and/or the detection range from a wide range designated with lines 700 to a smaller area 702. Optics 716 could also be used for “masking” a central area or only one of the lateral areas of the constructional field of view and/or the detection range.

Set 714 of preconfigured optics can consist of a plurality of Fresnel lenses. Generally, any optics is suitable which allows the desired customization. Optics 716 can be mounted within detector housing 708 either in a stationary mount which simplifies the installation process, or in a mount which is adjustable within detector housing 708 so as to allow for more options in the customization of the field of view and/or the detection range.

In Figure 10, a fifth example of DRAD 704 is shown. For the elements known from the previous embodiments, the same reference numerals are used, and reference is made to the above comments.

In the shown example, DRAD 704 comprises a screen 720 for customizing the field of view and/or the detection range of detector 114.

Screen 720 is mounted within detector housing 708 in front of sensor 706 so that any radiation from a source which is within the constructional detection area (marked here with lines 700) has to pass through screen 720. By changing the transmittance of certain portions of screen 720 as compared to the transmittance of other portions, the field of view and/or the detection range can be customized to the particular mounting condition and/or the detection requirements.

An example of screen 720 is shown in Figure 11. It has areas 722 where the transmittance is high, and areas 724 where the transmittance is low or non-existent (meaning that all radiation is being blocked).

In Figure 11, screen 720 is shown as having large pixels. This is only to illustrate the principle. In practice, screen 720 can have very small pixels so that the field of view and/or the detection range can be customized in a very precise manner.

For screen 720, electronic paper (“e-paper”) can be used. Areas where the transmittance shall be high are set to a state in which radiation (in particular infrared radiation) can pass basically unhindered, and areas which shall be excluded from the field of view and/or the detection range (in Figure 10 the areas outside the area delimited by lines 702) are set to a state in which radiation either cannot pass or is damped in a desired manner.

The control required for the configuration of screen 720 is not shown in the schematic figures here as it is well-known. It should be noted there that screen 720 does not necessarily have to have only two states (in terms of “black” or “white”), but can use intermediate states (“grey”) to allow for a specific customization.

As an alternative to a screen having a transmittance which can be adapted, it is also possible to use a screen having a configurable reflectivity.

In Figure 12, a sixth example of DRAD 704 is shown. For the elements known from the previous embodiments, the same reference numerals are used, and reference is made to the above comments.

DRAD 704 here consists in using two sensors 706A, 706B which are mounted within detector housing 708 in a stationary manner. The constructional field of view and/or the detection range of sensors 706A, 608B is different from each other, and the customization is achieved by electronically selecting from the entirety of signals provided by sensors 706A, 706B those signals which are the result of radiation emitted from a source which is within the customized field of view and/or the detection range.

In Figure 13, a seventh example of DRAD 704 is shown. For the elements known from the previous embodiments, the same reference numerals are used, and reference is made to the above comments.

DRAD 704 here is a MEMS 730 (microelectromechanical system) which allows for a customization of the field of view and/or the detection range.

MEMS 730 can comprise a plurality of micro-mirrors 732 which can be electronically switched between at least two positions. In one position, the incident radiation is reflected towards sensor 706 (please see micro-mirrors 730A), and in the other position, the incident radiation is reflected to areas which are outside of the field of view of sensor 706 (please see micro-mirrors 730B).

MEMS 730 can have other moveable elements instead of micro-mirrors. In general, any element is suitable which allows a customization of customization of the field of view and/or the detection range. An example of such element is a microlens.

In a manner similar to the second embodiment, the fifth to sevenths embodiments allow for customization which changes in accordance with specific patterns. The patterns can change according to the time (e.g. one pattern during daytime and one pattern during nighttime, or one pattern for weekdays and one pattern for the weekend). The customization can also involve a learning process which can be based on Al and data stored in the cloud so that the data of a high number of detectors 114 is available. The learning process can aim at reducing the number of false positives and/or at a reduction of the power consumption of the security installation by reducing the number of unnecessary activations of a camera associated with detector 114.

Claims

1. Detector (114) for detecting presence or motion in a security installation, the detector (114) having at least one sensor (706) for detecting thermal radiation, the detector (114) having a detection range adjustment device (DRAD).

2. The detector (114) of claims 1 wherein the DRAD (704) is mechanical.

3. The detector (114) of claims 2 wherein the DRAD (704) comprises a specific optics (716) chosen from a set (714) of predefined optics.

4. The detector (114) of claims 2 wherein the DRAD (704) comprises a specific cover (712) chosen from a set of predefined covers.

5. The detector of any of claims 2 to 4 wherein the DRAD (704) comprises an adjustable mounting structure for mounting the sensor (706) within a detector housing (708) so as to be tiltable.

6. The detector (114) of claims 5 wherein the mounting structure is adapted for orienting the sensor (706) in one of several predefined positions.

7. The detector (114) of claims 5 wherein the mounting structure is adapted for orienting the sensor (706) in one of an infinite number of continuously variable positions.

8. The detector of any of claims 5 to 7 wherein the mounting structure comprises a mechanical locking means for locking the sensor (706) in an adjusted position.

9. The detector of any of claims 5 to 7 wherein the mounting structure comprises an electrically operated adjustment mechanism (710).

10. The detector according to any of the preceding claims wherein the DRAD (704) comprises a screen (720).

11. The detector (114) of claims 10 wherein the transmittance of the screen (720) is configurable.

12. The detector (114) of claims 11 wherein the screen (720) comprises electronic paper.

13. The detector (114) of claims 10 or claim 11 wherein the reflectivity of the screen (720) is configurable.

14. The detector of any of the preceding claims wherein the DRAD (704) comprises a MEMS (730).

15. The detector (114) of claims 14 wherein the MEMS (730) is a micro-mirror array.

16. The detector (114) of claims 14 wherein the MEMS (730) is a mico-lens array.

17. The detector of any of the preceding claims wherein the DRAD (704) comprises an LCD display.

18. The detector of any of the preceding claims wherein the DRAD (704) is adapted for adjusting the vertical detection range.

19. The detector of any of the preceding claims wherein the DRAD (704) is adapted for adjusting the horizontal detection range.

20. The detector of any of the preceding claims wherein the DRAD (704) operates electronically.

21. The detector (114) of claim 20 wherein multiple sensors (706A, 706B) are present which are different from each other with respect to at least one of field of view angle and viewing range.

22. The detector of any of the preceding claims wherein the sensor (706) is a passive IR sensor (PIR).

23. The detector (114) of claim 22 wherein the PIR (706) is a multi-channel PIR.

24. The detector of any of the preceding claims wherein the sensor (706) is a TMOS sensor.

25. The detector of any of the preceding claims wherein the DRAD (704) comprises at least one electro-mechanically tiltable disc and/or dot and/ or pixel element, rotating disc.

26. The detector of any of the preceding claims wherein a collimator is used.

27. The detector of any of the preceding claims wherein the sensor (706) generates at least one output signal responsive to radiation incident on the sensor (706), the number of output signals defining an image resolution of the sensor (706), and wherein the number of output signals is less than five, optionally less than four, optionally less than three, optionally less than two.

28. The detector of any of the preceding claims, comprising optics configured to map radiation from a plurality of different source zones into overlapping areas sensed by the sensor.

29. A video doorbell comprising a detector as defined in any preceding claim.

30. A security camera comprising a detector as defined in any of claims 1 to 28.

31. A method comprising: a) providing a device for a security installation, the device optionally as defined in any of claims 1 to 30, the device comprising at least one sensor for detecting thermal radiation; and b) adjusting a setting of the device to set a field of view of the sensor to correspond to a desired monitoring area and/or monitoring range, with respect to the device.

32. A method according to claim 31, wherein the step of adjusting comprises (i) mechanically adjusting the device to set the field of view and/or (ii) electronically adjusting the device to set the field of view.