GB2613343A

GB2613343A - Motion sensor

Info

Publication number: GB2613343A
Application number: GB2117207.7A
Authority: GB
Inventors: Derham Michael
Original assignee: Mighton Products Ltd
Current assignee: Mighton Products Ltd
Priority date: 2021-11-29
Filing date: 2021-11-29
Publication date: 2023-06-07
Also published as: GB202117207D0

Abstract

A security sensor device 100 comprising a housing 102 having front 112 and rear 120 walls, defining a hollow interior, the front wall having an aperture 132 therethrough, a passive infrared sensor (166, Fig 3) aligned with the aperture and a photovoltaic module 106 releasably secured to the housing. The security sensor may be magnetically securable to a surface via a mounting device 104. The photovoltaic module may be secured to a lower side of the housing and may extend downwards. The photovoltaic module may be secured by a plug and socket arrangement, which may also comprise a clip. The security device may comprise an alarm system including a light source and speaker. The device may comprise a control system which may communicate remotely with another device. The photovoltaic module may be arranged to supply power to a rechargeable power supply.

Description

MOTION SENSOR

FIELD OF THE INVENTION

The present invention relates to security sensor devices. In particular, the present invention relates to a motion sensor device and an assembly comprising a motion sensor device.

BACKGROUND TO THE INVENTION

Security sensor devices are widely used as part of security systems, for example to detect the present of unauthorised persons. Such devices may comprise motion sensors, such as passive infrared (PIR) sensors configured to detect changes in infrared radiation indicative of human or animal movement.

Security sensor devices may be mounted on a wall inside or outside a building, to monitor an area of interest. It is desirable for such devices to be reliable and to require minimal maintenance. To reduce the complexity of installation, some security sensor devices comprise a power supply such as one or more batteries, so that the device does not need to be connected to a power supply of the building. Accordingly, the power supply of the device must be replaced and/or recharged at intervals to maintain power to the device.

Generally, a security sensor device is secured to a wall using fixings such as screws.

With this arrangement, removal of the device from the wall (for instance to replace batteries, or to reposition the device) may require tools, and may be time-consuming.

It is an object of the present invention to overcome at least one problem associated with the prior art, whether referred to herein or otherwise. -2 -

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a security sensor device comprising: a housing having a front wall and a rear wall, the housing defining a hollow interior and the front wall having an aperture therethrough; a passive infrared sensor aligned with the aperture; and a photovoltaic module; wherein the photovoltaic module is releasably securable to the housing.

Preferably the photovoltaic module is releasably securable to a lower side of the housing Preferably the photovoltaic module extends downwardly from a lower side of the 15 housing.

Preferably, the security sensor device comprises a plug and socket arrangement for releasably securing the photovoltaic module to the housing.

The security sensor device may comprise a clip arrangement for releasably securing the photovoltaic module to the housing.

The plug and socket arrangement may comprise the clip arrangement.

Preferably the housing comprises a socket and the photovoltaic module comprises a plug arranged to engage with the socket.

Preferably the socket is disposed on a lower side of the housing. Preferably the socket opens downwardly in use.

The photovoltaic module may be releasably securable to the housing by a friction-fit arrangement. -3 -

Preferably, the photovoltaic module is securable to the housing (solely) by pushing the photovoltaic module towards the housing.

Preferably, the photovoltaic module is releasable from the housing (solely) by pulling the photovoltaic module away from the housing.

The housing may comprise a first electrical connector and the photovoltaic module may comprise a second electrical connector and the first and second electrical connectors may be electrically connected when the photovoltaic module is secured to the housing.

Preferably the securement of the photovoltaic module to the housing simultaneously secures and/or suspends the photovoltaic module from the housing and electrically connects the photovoltaic module to the housing.

The security sensor device may comprise a lens disposed in the aperture.

Preferably the security sensor device comprises an alarm system comprising a light 20 source and a speaker.

Preferably, the security sensor device comprises a control system for controlling the alarm system, the control system being configured to receive a signal from the sensor and being configured to activate the alarm system on receipt of a signal from 25 the sensor.

Preferably the security sensor device comprises a rechargeable power supply, wherein the photovoltaic module is arranged to supply power to the rechargeable power supply.

Preferably the sensor faces in a forward direction generally perpendicular to a plane of the front wall and the photovoltaic module is angled to extend in the forward -4 -direction (away from the front wall).

The photovoltaic module may be releasably securable to the housing by a snap-fit arrangement, a clip arrangement, and/or an interference fit (friction fit).

The security sensor device may comprise communication means configured to communicate with a remote device. The communication means may comprise a Bluetooth module. The control system may be configured to exchange information with the communication means. The control system may be configured to disable the alarm system on receipt of a signal from a remote device.

The aperture may be a first aperture and a second aperture may be provided in the front wall spaced apart from the first aperture, wherein the light source is arranged to emit light through the second aperture.

The light source may be configured to emit a pulse of light when activated by the control system. The light source may flash or strobe when activated by the control system.

The photovoltaic module may comprise a photovoltaic panel having a planar surface which extends in a plane at an angle to a plane of the front wall of the housing.

The photovoltaic module may comprise a photovoltaic panel having a planar surface which extends in a plane at an angle to a centreline of a field of view of the sensor.

According to a second aspect of the invention there is provided an assembly comprising the security sensor device and a mounting device for mounting the security sensor device to a surface, wherein the security sensor device is magnetically secured to the mounting device.

Preferably the security sensor device is solely/exclusively magnetically secured to the mounting device. Accordingly, no mechanical clips/securement devices are -5 -required in such an arrangement.

The security sensor device may comprise one or more magnets and the mounting device may comprise a ferromagnetic material.

The security sensor device may be arranged to be pivotally mounted to the mounting device.

The rear wall of the security sensor device may comprise a concave portion arranged to engage with a generally hemispherical portion of the mounting device.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described, by way of example only, with reference 15 to the accompanying drawings, in which: Figure 1 is an upper perspective view of a security sensor device according to the invention; Figure 2 is a side view of the security sensor device of Figure 1; Figure 3 is a cross-sectional side view of the security sensor device of Figure 1; Figure 4 is a cross-sectional top view of the security sensor device of Figure 1; Figure 5 is a cross-sectional front view of part of the security sensor device of Figure 1; Figure 6 is a cross-sectional front view of part of the security sensor device of Figure 1; Figure 7 is a lower perspective view of the security sensor device of Figure 1; and -6 -Figure 8 is a lower perspective view of part of the security sensor device of Figure 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a security sensor device for detecting movement. The security sensor device is configured to produce a visual and/or audible alert upon detection of movement.

In this description, the security sensor device is described with reference to mounting the device to a supporting surface such as a wall. Accordingly, the terms "upwardly", "upper" and related terms refer to a direction generally away from gravity in use (e.g. towards the top in Figures 1 and 2). The terms "downwardly", "lower" and related terms refer to an opposite direction (e.g. towards the bottom in Figures 1 and 2). It will be appreciated however that the device could be used in other orientations.

Referring to Figures 1 to 5, a security sensor device 100 according to a first embodiment of the invention comprises a main housing 102, a mounting device 104 and a photovoltaic module 106. The main housing 102 comprises circuitry and components for detecting motion and for producing an alarm signal. The mounting device 104 is arranged to mount the main housing 102 to a supporting surface (not shown). The photovoltaic module 106 is arranged to provide a supplementary power source and is detachable from the main housing 102, as described further below.

The main housing 102 comprises a front portion 108 and a rear portion 110. The front portion 108 comprises a generally rectangular front wall 112 which forms a front side 114 of the main housing 102. The front wall 112 is arranged to extend generally vertically in use, between a lower side 116 of the housing 102 and an upper side 118 of the housing 102. The rear portion 110 comprises a generally rectangular rear wall 120 spaced apart from the front wall 112. The rear wall 120 forms a rear side 122 of the main housing 102. Side walls 124 extend between the -7 -front and rear walls 112, 120. The side walls 124 are formed by front side wall portions 126 which extend rearwardly from edges of the front 112 wall towards the rear portion 110 and rear side wall portions 128 which extend forwardly from edges of the rear wall 120, towards the front portion 108. The front and rear portions 108, 110 of the main housing 102 together define a hollow interior 130 of the main housing 102, as can be seen most clearly in Figure 3. The front and rear portions 108, 110 are secured together by fasteners, as described further below.

A first aperture (window), which in this embodiment is a sensor aperture 132, passes through the front wall 112, between the front side 114 of the housing 102 and the hollow interior 130. A second aperture (window), which in this embodiment is a light source aperture 134, also passes through the front wall 112 between the front side 114 of the housing 102 and the hollow interior 130. The sensor aperture 132 is disposed in a recessed portion 136 of the front wall 112. The light source aperture 134 is spaced above the sensor aperture 132, between the sensor aperture 132 and the upper side 118 of the main housing 102.

With reference to Figures 3 and 4, the hollow interior 130 is divided by a partition member 152 disposed between the front wall 112 and the rear wall 120. The partition member 152 extends in a plane generally parallel to a plane of the front wall 112.

The partition member 152 extends between opposing side walls of the main housing 102. In this way, the partition member 152 divides the hollow interior 130 into a front chamber 154, between the partition member 152 and the front wall 112, and a rear chamber 156, between the partition member 152 and the rear wall 120. In this embodiment, the sensor device 100 comprises a printed circuit board (PCB) 158 mounted in the hollow interior 130. The PCB 158 is disposed in the front chamber 154, spaced apart from the front wall 112. The PCB 158 extends generally parallel to the plane of the front wall 112.

The rear portion 110 is secured to the partition member 152 by fasteners in the form of screws 160, as can be seen in Figure 4. The partition member 152 is secured to the front portion 108 by screws 165 (visible in Figure 5). In this way, the front and -8 -rear portions 108, 110 are secured together. The rear portion 110 comprises a peripheral rim 162 arranged to engage with a corresponding peripheral groove 164 of the front portion 108.

With reference to Figure 5, the main housing 102 comprises a socket 138 for attaching the photovoltaic module 106 (not shown in Figure 5) to the main housing 102. The socket 138 comprises an opening 140 which passes through a lower side wall 142 on the lower side 116 of the main housing 102. The opening 140 passes from the lower 116 side of the main housing 102 into the hollow interior 130. A skirt 144 extends part way around the opening 140 and downwardly from the lower side wall 142.

Retaining members 146 are disposed on opposite sides of the opening 140. Each retaining member 146 projects upwardly into the hollow interior 130 from the lower side wall 142 adjacent the opening 140. In this embodiment, two retaining members 146 are provided. An upper end of each retaining member comprises a ramped surface 148 which faces upwardly and towards the opposing retaining member 146. The retaining members 146 are arranged to engage with part of the photovoltaic module 106, as described further below. A first electrical connector 150 is disposed in the socket 138. The first electrical connector 150 is arranged to provide an electrical connection between the photovoltaic module 106 and the circuitry and components (described further below) disposed in the main housing 102.

The sensor device 100 further comprises a sensor arrangement, an alarm system 25 and a control system.

In the present embodiment, the sensor arrangement comprises a passive infrared (FIR) sensor 166 for detecting changes in infrared radiation associated with movement, such as movement of a person. As can be seen in Figures 3 and 4, the FIR sensor 166 is mounted on the PCB 158, in alignment with the sensor aperture 132. In this way, the FIR sensor 166 is arranged to detect infrared radiation passing through the sensor aperture 132 A sensor lens 168 is mounted in the sensor -9 -aperture 132. The sensor lens 168 comprises a generally hemispherical lens portion 170 and a generally annular mounting portion 172. The mounting portion 172 is mounted to the PCB 158 and the lens portion 170 protrudes through the sensor aperture 132. The FIR sensor 166 is disposed in a cavity defined by the PCB 158 and a hollow interior of the sensor lens 168. With this arrangement, the FIR sensor 166 is disposed behind the lens portion 170 when viewed from a front side of the sensor device 100 (corresponding to the front side 114 of the housing 102). The sensor lens 168 is arranged to focus light (e.g. infrared light/radiation) on to the FIR sensor 166. In this way, light incident on a front side of the lens 168 is focussed on to the FIR sensor 166. A field of view of the sensor lens 168 faces generally forwards, away from the front side of the device 100. In this embodiment, the sensor lens 168 is a Fresnel lens. In some embodiments the sensor lens may comprise a wide-angle lens. For example, the sensor lens may have a field of view of about 120°. In other embodiments, there is not a sensor lens, and the aperture may provide an uninterrupted passage between the FIR sensor and the front side of the device, or the aperture may be provided with a window (e.g. substantially transparent material) which allows light/radiation to reach the FIR sensor.

The alarm system comprises a light source and a speaker 174. In this embodiment, the light source comprises a LED 176 and a LED lens 178 mounted on the PCB and aligned with the light source aperture 134. The LED lens 178 is arranged to transmit light from the LED 176 forwardly through the light source aperture 134. The alarm system is configured to cause the LED 176 to emit light when motion is detected by the FIR sensor 166.

The alarm system is configured to cause the speaker 174 to emit a sound when movement is detected by the FIR sensor 166. The speaker 174 is mounted in the front chamber of the hollow interior. The speaker 174 is aligned with a reduced thickness portion of the front wall, to allow sound to pass through the front wall in use. In this embodiment, the speaker 174 comprises a waterproof speaker.

The control system (not shown) is configured to control the alarm system. The -10 -control system comprises circuitry connected to the sensor arrangement and the alarm system. The control system comprises a processor system (e.g. one or more microprocessors). The control system is configured to receive signals from the sensor arrangement and to activate the alarm system on receipt of a signal from the sensor arrangement. In this embodiment, when the FIR sensor 166 detects motion, the control system activates the alarm system, causing the LED 176 to illuminate and the speaker 174 to emit a warning sound. In some embodiments, the control system may cause the LED 176 to flash or strobe when movement is detected.

With these arrangements, the sensor device 100 is configured to detect movement such as movement of unauthorised persons in a room or other space. The control system is configured to disable the alarm system under particular circumstances. For example, in this way, the sensor device 100 may be deactivated by a user.

The sensor device 100 further comprises communication means, which in this embodiment comprises a Bluetooth chip 180. The communication means is configured to communicate with a remote device. For example, the communication means may communicate with a smartphone device, and/or a communications hub. In this way, the sensor device 100 may transmit data (e.g. relating to the detection of movement by the sensor) to a user or central hub. The communication means is connected to the control system so that the sensor device 100 may be controlled remotely. For example, the alarm system may be deactivated remotely by a user. The sensor device 100 may form part of a (smart) home security system.

The sensor device 100 comprises a power supply. In this embodiment, the power supply comprises a rechargeable power supply in the form of rechargeable batteries 182. The batteries 182 are disposed in the rear chamber 156 of the main housing. A rear side of the partition member 152 is shaped to provide a tray in which the batteries 182 are mounted. With this arrangement, the power supply is separated from the PCB 158 and components mounted in the front chamber 154 by the partition member, so that the batteries 182 can be accessed (e.g. for replacement) by a user without requiring access to the front chamber 154. This may reduce the risk of damage to the PCB 158 and the components in the front chamber 154.

Referring additionally to Figures 6 to 8, the photovoltaic module 106 is arranged to be releasably attached to, and detached from, the main housing 102 in use. As can be seen most clearly in Figures 1 and 7, the photovoltaic module 106 comprises a body 184, a photovoltaic panel 186 and a connecting portion comprising a plug assembly 188. Figures 1 to 4 show the photovoltaic module 106 attached to the main housing 102. Figure 5 shows the main housing 102 with the photovoltaic module omitted. Figure 6 shows part of the photovoltaic module 102 secured to the main housing 102, as described further below. Figure 7 shows the photovoltaic module 106 detached from the main housing 102.

The body 184 comprises a generally rectangular frame 190 having a first, upper edge 192 and a second lower edge 194. The frame 190 defines a generally rectangular opening 196. The photovoltaic panel 186 is mounted in the frame 190.

The photovoltaic panel 186 is generally rectangular and is mounted in the rectangular opening 196 of the frame 190. The photovoltaic panel 186 extends in a plane generally parallel with a plane of the frame 190. The photovoltaic panel 186 and the frame 190 define a generally planar front side 198 of the photovoltaic module 106.

The plug assembly 188 is arranged to connect the photovoltaic module 106 to the main housing 102 of the sensor device 100. In this way, the photovoltaic module 106 may be releasably secured to the main housing 102. The plug assembly 188 extends from the upper edge 192 of the frame 190, so that when the photovoltaic module 106 is attached to the main housing 102, the upper edge 192 is disposed proximate the main housing 102. In particular, the upper edge 192 is disposed adjacent the lower side 116 of the main housing 102. In this embodiment, part of the plug assembly 188 is shaped to engage with the socket 138 in the main housing 102.

Figure 6 shows the plug assembly 188 engaged with the socket 138, with the frame and photovoltaic panel 186 omitted. The plug assembly 188 comprises a pair of spaced apart clip arms 202. The clip arms 202 are elongate and extend away from the upper edge 192 of the frame 190. Each clip arm 202 comprises an enlarged head 204 which is arranged to engage with a respective one of the retaining members 146 when the plug assembly 188 is engaged with the socket 138. In particular, a ramped surface 206 of each enlarged head 204 is arranged to engage with the ramped surface 148 of the respective retaining member 146. With this arrangement, the plug assembly 188 can be releasably retained in the socket 138.

The photovoltaic module 106 further comprises circuitry and an electrical connector 208. In this embodiment, the electrical connector 208 comprises a second electrical connector of the sensor device 100. The circuitry comprises an auxiliary PCB 210 mounted in the plug assembly 188. The second electrical connector 208 is mounted to the auxiliary PCB 210. The circuitry is configured to transmit power from the photovoltaic panel 186 to the second electrical connector 208. The second electrical connector 208 is arranged to connect to the first electrical connector 150 disposed in the main housing 102.

To connect the photovoltaic module 106 to the main housing 102, the plug assembly 188 is inserted into the socket 138. The clip arms 202 are deflected towards one another to allow the enlarged heads 204 to be inserted into the opening 140. Once the plug assembly 188 is fully inserted into the socket 138, the enlarged heads 204 return outwardly away from one another, into engagement with the retaining members 146. In this way, the plug assembly 188 and socket 138 provide a 'snap fit' arrangement. The first electrical connector 150 engages, and connects electrically, with the second electrical connector 208. In this embodiment, the second electrical connector 208 comprises male contacts (pins) which insert into corresponding female contacts provided in the first electrical connector 150.

To detach the photovoltaic module 106 from the main housing 102, the photovoltaic module 106 can be pulled away from the main housing 102 so that the plug assembly 188 is withdrawn from the socket 138. As the plug assembly 188 is pulled -13 -out from the socket 138, the clip arms 202 are deflected inwardly as the enlarged heads 204 pass over the ramped surfaces 148 of the retaining members 146. As the photovoltaic module 106 is pulled away from the main housing 102, the first and second electrical connectors 150, 208 are disconnected from one another.

In this way, the photovoltaic module 106 is attachable to the main housing 102 simply by pushing the photovoltaic module 106 towards the main housing 102. The photovoltaic module 106 is removable simply by pulling the photovoltaic module 106 away from the main housing 102. Accordingly, the photovoltaic module 106 is attachable or detachable from the main housing 102 by a push/pull operation. No additional mechanical operations are required. For example, a user is not required to operate a button, clip, lever or similar in order to attach or release the photovoltaic module 106. It will be appreciated that, with the arrangement described above, the photovoltaic module 106 is both mechanically supported and electrically connected to the main housing 102 by a single operation (e.g. pushing the plug assembly into the socket). In this way, the device 100 comprises a single point of connection for both mechanical attachment and electrical connection of the photovoltaic module 106. Therefore a user is not required to perform multiple operations in order to connect the photovoltaic module 106 mechanically and electrically to the main housing 102. In other embodiments, the clip arms may be absent, and the photovoltaic module may be secured to the housing by an interference fit, or friction-fit arrangement. For example, part of the plug assembly may be an interference fit in the socket.

As described above, the photovoltaic module 106 can be conveniently attached to, or detached from, the main housing 102. When connected to the main housing 102, the photovoltaic module 106 is arranged to supply power to the PCB 158 in the main housing 102. The photovoltaic module 106 may supply power to recharge the batteries 182 and/or to provide supplementary power to the circuitry and components in the main housing 102 (e.g. the alarm system, control system and sensor arrangement). In this way, the photovoltaic module 106 may be used to extend an operating lifetime (e.g. battery life) of the sensor device 100. When the -14 -photovoltaic module 106 is not attached to the main housing 102, a sealing plug 212 (comprising clip arms for engagement with the socket and a sealing gasket (not shown)) may be inserted into the socket 138 (as shown in Figure 8) to seal the housing 102. In this way, contamination (e.g. dust, moisture) may be prevented from entering the hollow interior 130.

As shown most clearly in Figures 1 and 2, in use, the photovoltaic module 106 is disposed below the main housing 102 and extends downwardly from the lower side 116 of the main housing 102. The photovoltaic module 106 extends forwards away from the front side 114 of the main housing 102. A plane of the front side 198 of the photovoltaic module 106 extends at an angle to a plane of the front side 116 of the main housing 102. In this way, when the main housing 102 is oriented so that the front wall 112 extends generally vertically, the photovoltaic panel 186 faces in a direction forwards and upwards. With this arrangement, the photovoltaic panel 186 may be oriented to improve light capture (e.g. from a light source on a ceiling, or from sunlight). Since the photovoltaic panel 186 is positioned at least partly in front of the front side 114 of the main housing 102, the effect of shading of the panel 186 by the main housing 102 is reduced.

With the photovoltaic module 106 mounted underneath the main housing 102, the photovoltaic module 106 is protected from dust, debris, and water (e.g. from precipitation if the device 100 is mounted outdoors). In particular, the electrical connectors 150, 208 are protected from water, since they are shielded by the main housing 102. Also, when the photovoltaic module is attached, the connectors 150, 208 are sealed in the hollow interior 130 by the plug assembly 188. The skirt 144 helps to seal the connection between the photovoltaic module 106 and the main housing 102.

The sensor device 100 is arranged to be mounted to a supporting surface such as 30 a wall (not shown). The mounting device 104 is arranged to secure the main housing 102 to the supporting surface. In use, the mounting device 104 is secured to the supporting surface, and the main housing 102 is mounted to the mounting device 104. The main housing 102 is pivotally mounted to the mounting device 104 so that an angle of the main housing 102 can be adjusted with respect to the supporting surface. In this way, the field of view of the sensor lens 168 can be adjusted so that a chosen area can be monitored for movement.

Referring again to Figures 2 to 4, the mounting device 104 comprises a generally disc shaped mounting portion 214 for securing to the supporting surface, and a generally hemispherical engagement portion 216 for engaging with the main housing 102 of the sensor device 100. The rear wall 120 of the main housing 102 comprises a concave recess 218 on the rear (outer) side 122 of the rear wall 120.

The recess 218 has a shape complementary to an outer surface of the engagement portion 216. With this arrangement, the engagement portion 216 is shaped to engage with the recess 218 so that the orientation of the main housing 102 can be adjusted with respect to the mounting device 104. The engagement portion 216 comprises a ferromagnetic material and the main housing 102 comprises magnets 220 disposed in the hollow interior 130 proximate the recess 218. In this way, the main housing 102 is releasably mounted to the mounting device 104. In this embodiment, two magnets 220 are provided in a spaced apart arrangement. Each magnet 220 is mounted in a corresponding frame 222 provided on an inner surface of the rear wall 120. Accordingly, the magnets 220 are disposed between the partition member 152 and the rear wall 120. Each magnet 220 may be an interference fit in its respective frame 222. In some embodiments the magnets 220 may be held in place by the partition member 152.

With the arrangement described above, the main housing 102 is readily detachable from the mounting device 104. Detaching the main housing 102 from the mounting device 104 may allow a user to attach or remove the photovoltaic module 106 more conveniently. For example, where the sensor device 100 is mounted on a wall adjacent a ceiling (which may be at a height requiring a user to reach upwards), the user can unmount the main housing 102 from the mounting device 104 before attaching or removing the photovoltaic module 106 from the main housing 102 and/or replacing the batteries 182. Once the photovoltaic module 106 has been -16 -attached or detached from the housing 102 as desired, the housing 102 can be readily remounted to the mounting device 104.

Alternatively, the photovoltaic module 106 may be attached or detached from the main housing 102 whilst the main housing 102 remains attached to the mounting device 104. It will be appreciated that the photovoltaic module 106 is disposed on the lower side 116 of the main housing 102 in use, so that it can be reached more easily by a user when the sensor device 100 is mounted on a wall. In this way, the photovoltaic module 106 may be readily removed or installed by a user without detaching the main housing 102 from the supporting surface.

In use, a plurality of mounting devices 104 may be fitted in different locations (e.g. in different rooms of a house and/or in different buildings). In this case, one or more main housings 102 (with or without a photovoltaic module 106 attached) may be conveniently moved between different locations by attaching the main housing 102 to a selected one of the mounting devices 104. With this arrangement, one or more housings 102 may be portable between different locations (e.g. between different buildings or properties). A main housing 102 may be used temporarily (e.g. a main housing 102 may be mounted on a mounting device 104 to provide security while a building is unoccupied). Alternatively, a user may transport a main housing 102 to a particular building for use whilst the user is using that building. The magnetic mounting allows the main housing 102 to be conveniently installed (by mounting to a preinstalled mounting device 104) without the use of tools.

The user may choose to attach or remove the photovoltaic module 106 (to/from the main housing 102) depending on where the sensor device 100 is to be located. For example, in a room having relatively lower light levels, the photovoltaic module 106 may be removed, so that the sensor device 100 is less bulky and has a more discrete appearance. On an external wall, where the sensor device 100 may be exposed to higher light levels, the user may choose to attach the photovoltaic module 106 to increase battery life.

-17 -Advantageously, the use of magnets 220 means that a mechanical mounting mechanism is not required to mount the main housing 102 to the mounting device 104. Accordingly, the connection between the main housing 102 and the mounting device 104 is not susceptible to dirt and/or debris and does not mechanically deteriorate with repeated use.

It will be appreciated that the photovoltaic module 106 may be removed from, or attached to, the main housing 102 without using tools. In other embodiments, the photovoltaic module may be attached to the main housing by a bayonet arrangement, snap ring arrangement, or other suitable releasable connecting arrangement. In the embodiment described above, the angle of the photovoltaic panel 186 is fixed with respect to the main housing 102. In this way, the orientation of the field of view of the sensor lens 168 and the angle of the photovoltaic panel 186 may be adjusted simultaneously. The relatively large field of view provided by the sensor lens 168 (Fresnel lens) means that the sensor device 100 can be used to monitor an area of interest whilst allowing the photovoltaic panel 186 to be angled to improve light capture. In other embodiments, the photovoltaic panel 186 and/or the photovoltaic module 106 may be pivotally mounted with respect to the main housing 102 to allow the angle of the photovoltaic panel 186 to be adjusted independently of the field of view of the sensor lens 168.

The sensor device 100 may be mounted on an internal or external wall of a building. In the present embodiment, the sensor device 100 comprises waterproofing components such that the hollow interior 130 of the main housing 102 is substantially sealed. An 0-ring seal 224 is provided between the front and rear portions 108, 110 of the main housing 102. Additionally, an 0-ring seal 226 is provided between the LED lens 178 and the light source aperture 134 and a sealing gasket 228 is provided between the sensor lens 168 and the sensor aperture 132. A sealing gasket 230 is provided between the plug assembly 188 of the photovoltaic module 106 and the socket 138. Accordingly, the sensor device 100 is substantially sealed against water ingress and may be used outdoors.

-18 -Overall, the present invention provides a security sensor for detecting movement. The security sensor may be used indoors or outdoors, and may form pad of a home security system.

Claims

-19 -CLAIMS1. A security sensor device comprising: a housing having a front wall and a rear wall, the housing defining a hollow interior and the front wall having an aperture therethrough; a passive infrared sensor aligned with the aperture; and a photovoltaic module; wherein the photovoltaic module is releasably securable to the housing.
2. A security sensor device according to Claim 1, wherein the photovoltaic module is releasably securable to a lower side of the housing.
3. A security sensor device according to Claim 1 or Claim 2, wherein the photovoltaic module extends downwardly from a lower side of the housing.
4. A security sensor device according to any preceding claim, comprising a plug and socket arrangement, the plug being arranged to engage with the socket for releasably securing the photovoltaic module to the housing.
5. A security sensor device according to Claim 4, wherein the housing comprises the socket and the photovoltaic module comprises the plug.
6. A security sensor device according to Claim 4 or Claim 5, wherein the plug and socket arrangement comprises a clip arrangement for releasably securing the photovoltaic module to the housing.
7. A security sensor device according to any of Claim 4 to Claim 6, wherein the socket opens downwardly in use.
8. A security sensor device according to any preceding claim, wherein the photovoltaic module is securable to the housing solely by pushing the photovoltaic module towards the housing.
9. A security sensor device according to any preceding claim, wherein the photovoltaic module is releasable from the housing solely by pulling the photovoltaic module away from the housing.
10. A security sensor device according to any preceding claim, wherein the housing comprises a first electrical connector and the photovoltaic module comprises a second electrical connector and the first and second electrical connectors are electrically connected when the photovoltaic module is secured to the housing.
11. A security sensor device according to any preceding claim, comprising an alarm system comprising a light source and a speaker.
12. A security sensor device according to any preceding claim, comprising a control system for controlling the alarm system, the control system being configured to receive a signal from the sensor and being configured to activate the alarm system on receipt of a signal from the sensor.
13. A security sensor device according to Claim 12, comprising communication means configured to communicate with a remote device, wherein the control system is configured to exchange information with the communication means and wherein the control system is configured to disable the alarm system on receipt of a signal from the remote device.
14. A security sensor device according to any preceding claim, comprising a rechargeable power supply, wherein the photovoltaic module is arranged to supply power to the rechargeable power supply.
15. A security sensor device according to any preceding claim, wherein the sensor faces in a forward direction generally perpendicular to a plane of the front wall and the photovoltaic module is angled to extend in the forward direction.
16. A security sensor device according to any preceding claim, wherein the photovoltaic module comprises a photovoltaic panel having a planar surface which extends in a plane at an angle to a plane of the front wall of the housing and wherein the planar surface extends in a plane at an angle to a centreline of a field of view of the sensor.
17. An assembly comprising the security sensor device of any preceding claim, and a mounting device for mounting the security sensor device to a surface, wherein the security sensor device is magnetically securable to the mounting device.
18. An assembly according to Claim 17 in which the security sensor device is solely magnetically secured to the mounting device.
C\I 15 19. An assembly according to Claim 17 or Claim 18, wherein the security sensor device comprises one or more magnets and the mounting device comprises a ferromagnetic material.
20. An assembly according to any one of Claim 17 to Claim 19, wherein the security sensor device is arranged to be pivotally mounted to the mounting device.
21. An assembly according to any of Claim 17 to Claim 20, wherein the rear wall of the security sensor device comprises a concave portion arranged to engage with a generally hemispherical portion of the mounting device.