WO2007011207A1

WO2007011207A1 - Detection camera

Info

Publication number: WO2007011207A1
Application number: PCT/NL2006/000359
Authority: WO
Inventors: Johannes Petrus Marinus Cornelis Van Schijndel
Original assignee: Internova Holding Bvba
Priority date: 2005-07-18
Filing date: 2006-07-12
Publication date: 2007-01-25
Also published as: NL1029960C1; EP1908033A1

Abstract

A camera module (100) is described, comprising: a housing (20); an image sensor (22) mounted in the housing (20) for providing image signals (Sb) of a guarded zone (3) outside the housing; a controller (30) mounted in the housing (20) with an image input (32) for receiving the image signals (Sb) from the image sensor (22); an image output (26) for providing image output signals (Sw); a detection output (25) for providing a detection output signal (Sd); wherein the controller (30) is adapted to process the image signals (Sb) received at its image input (32) in order to detect a movement, and to generate the detection output signal (Sd) depending on the result of this movement detection. The controller (30) is further adapted to only output the image output signals (Sw) after a detected movement.

Description

Title: Detection camera

The present invention relates in general to a camera for guarding purposes.

For the purpose of guarding objects such as houses and business properties, it is known per se to make use of one or more cameras. In that context, a camera may ^"be arranged outside the house concerned, in order to make image recordings of the outside of the house and/or surroundings, or a camera may be arranged inside the house concerned, in order to make image recordings of a zone to be guarded inside the house (in particular in shops) . The purpose of such cameras is then primarily providing image information.

It is known to register the image recordings on a registration medium, for instance a video tape or a hard disk, so that, when an event such as a burglary or a raid has occurred, it is possible to view the recordings afterwards in order to find out what has happened when and hopefully to recognize the perpetrator (s) . In this context, it is a problem that storing camera images requires relatively much memory space. Normal video tapes for example have a playing time of at most 4 hours at normal recording speed. This means that one has to change video tapes quite often. Since it is desired to limit the changing of video tapes as much as possible, preferably not more often than once a day, strategies have been developed to be able to record the recordings of a longer period of time on a single tape, but those strategies are associated with loss of image quality.

It is also known to send the image recordings to a central guarding post, where the recordings are shown live on a monitor or the like, and where a guard views the monitor images and takes action if he establishes trouble. In this context, it is a problem that "nothing happens" under normal circumstances, so that -there is a risk that the attention of the guard wanes. At the central guarding post, it is further customary that the incoming camera images are registered on a registration medium, in order to be able to serve as possible evidence, in which case the afore-mentioned problems occur. For the purpose of guarding objects such as houses and business properties, it is also known per se to make use of one or more event detectors, which are designed for detecting a particular event and then to generate a detection signal. Based on this detection signal, an alarm signal can then be generated, like for instance a siren, or an alarming signal can be sent to a central guarding post. Known detectors are for example window-pane breaking detectors, infrared movement detectors, etc.

An important object of the present invention is providing an improved camera, which is usable as stand-alone apparatus but also as module in a guarding system.

According to an important aspect of the present invention, the camera is also suitable as detector.

These and other aspects, features and advantages of the present invention will be explained in more detail by the following description with reference to the drawings, in which same reference numerals indicate same or similar parts, and in which: figure 1 is a schematic top view of a house and a guarding camera; figure 2 is a block diagram schematically illustrating details of a detection camera according to the present invention; figure 3 is a schematic perspective view of a preferred embodiment of a housing of the detection camera.

Figure 1 is a schematic top view of an arrangement of a house 1 and a detection camera system 100 according to the present invention. Although the detection camera system 100 may be adjustable, it is preferably fixedly mounted. The detection camera system 100 comprises a camera 10, of which entrance optics 11 define a field of sight 12 directed towards the house 1. The part of the house 1 which is situated in the field of sight 12 of the camera 10 is indicated as guarded house part 2. Together with the space 3 between camera 10 and house 1, situated within the field of view 12, the guarded house part 2 forms a guarded zone 3.

The detection camera system 100 has an input connection 13 for receiving supply voltage, for instance 12V, and an output connection 14 for giving output signals, as will be explained in more detail.

In functional respect, the detection camera system 100 according to the present invention is a combination of a camera and a detector, which will therefore also be indicated hereinafter as detector/camera or briefly "sense cam".

Figure 2 is a block diagram schematically illustrating inventive details of the sense cam 100 according to the present invention. By the reference numeral 20, the housing of the sense cam 100 is schematically indicated; this housing may be made as a high-quality, anodized housing which is suitable for use outside, and which is strong enough to be highly resistant to vandalism.

The camera 10 has a lens system 21 which projects the received light onto an image sensor 22 arranged inside the housing 20. The lens system 21 preferably has a fixed focus setting, and may have a viewing angle of approximately 70°. Although the image sensor may be a black-and-white detector, it is preferably a colour sensor. In the preferred embodiment, the image sensor is a CCD sensor of high quality, suitable for providing an image of 480 lines or more, with 640 pixels or more per line. Since CCD sensors are known per se, and since the present invention can be implemented using a CCD sensor known per se, it is not necessary to explain the construction and functioning of a CCD sensor here. In addition to visible light, the image sensor 22 is also sensitive to infrared light with a wavelength in the order of 800 ran.

The sense cam 100 further comprises a light intensity sensor 23 and an infrared light source 24, both mounted in a front of the housing 20. The light intensity sensor 23 is adapted for measuring the amount of surrounding light, and gives a measuring signal Si to a first detector input 33 of a controller 30, for instance a suitably programmed microprocessor. When the measuring signal Si indicates that the light level has dropped below a predetermined first value, the controller 30 gives a control signal Cir for the infrared light source 24 at a control output 34, in order to switch on this light source 24. When the measuring signal Si indicates that the light level has risen above a predetermined second value, the controller 30 gives the control signal Cir at a control output 34, in order to switch off the infrared light source 24. In order to prevent undesired flickering of the light source 24, the value of the second light level is preferably higher than the value of the first light level. The infrared light source 24 is mounted in such a way that it illuminates at least an important part of the guarded zone 3. Due to automatically switching on the infrared light source 24, the camera 10 is suitable to make good and clear image recordings also in dark circumstances (twilight, evening, night) . The infrared light source 24 is advantageously built up as an array of infrared LEDs, and the wavelength range of the emitted infrared light is advantageously tuned to the sensitivity range of the CCD sensor 22, and has thus typically an intensity maximum in the vicinity of 800 nm.

In a variation, it is possible that the infrared light source 24 is directly controlled by the light intensity sensor 23, without interference of the controller 30. In that case, the infrared light source 24 may be provided with a functionality for comparing the measuring signal Si of the light intensity sensor 23 with predetermined values.

It is also possible that the light intensity sensor 23 is adapted for giving a measuring signal Si having a first value if the light level has dropped below a predetermined first level, or a second value if the light level has risen above a predetermined second value.

At an image input 32, the controller 30 receives the image signal Sb generated by the CCD sensor 22. In a variation, it is possible that the controller 30 is adapted to process the image signal Sb in order to calculate the level of the surrounding light, and in order to generate the control signal Cir for the infrared light source 24 based on the result of this calculation; in that case, the separate light sensor 23 can then be omitted.

The controller 30 is provided with image processing software, with which the controller 30 is capable of detecting whether a movement is occurring in the guarded zone Z. The image processing software is preferably intelligent enough to ignore the movement of leaves in the wind or the movement of small animals. Because of this image processing software, the sense cam 100 also behaves as a movement detector.

The controller 30 has a detection output 35 coupled with a detection output 25 of the sense cam 100, for providing a detection output signal Sd which is indicative for a movement established by the controller 30. Further, the sense cam 100 has an image output 26 for providing image signals Sw, coupled to an image output 36 of the controller 30. The controller 30 is adapted to convert the image signal Sb generated by the CCD sensor 22 to a signal shape suitable for displaying on a monitor or TV or similar display apparatus. In figure 2 is shown that the detection output signal Sd provided at the detection output 25 is received by a receiver 40, as well as the image signals Sw provided at the image output 26. The connection may for example be formed by UTP, twisted pair, or minicoax cabling. This receiver 40 may simply be a recording apparatus for recording the image signals Sw on a storage medium such as for instance a hard disk. However, this receiver 40 may also be a central guarding post, where the image signals Sw are displayed on a monitor or the like. In a possible embodiment, the controller 30 continuously provides the images signals Sw to the image output 26. The receiver 40 thus continuously receives image signals, also during normal circumstances when no events occur. Because the receiver 40 also receives the detection output signal Sd, the receiver 40 knows that nothing is going on, and that the image signals do not have to be processed, thus do not have to be recorded and/or displayed. Thus, no unnecessary use is made of the storage capacity of the storage medium and/or of the guarding capacity of the central post, and the guarding personnel is better able to concentrate on images where actually something is going on. Only when the detection output signal Sd indicates the occurrence of an event (detected movement) , the receiver 40 is triggered for taking action such as recording and/or displaying image signals. It is noted that, in this case, the image output 26 may be directly coupled to the image sensor 22, if the sensor output signal Sb itself is suitable for recording and display.

In another embodiment, the controller 30 only provides the image signals Sw to the image output 26 after a detected event. After all, since the receiver 40 does not do anything with the image signals under normal circumstances, these signals do not need to be sent. Because of this, the data connection between the sense cam 100 and the receiver 40 is loaded less, and is only loaded when it is necessary.

In such an embodiment, it is possible that, in addition to the image signals Sw, no separate detection output signal Sd is sent to the receiver 40. Since the controller 30 only sends the image signals Sw after a detected event, the image signals Sw themselves can fulfil the function of detection output signal Sd, and the receiver 40 can consider the reception of the image signals Sw as a trigger signal for taking action such as recording and/or displaying image signals . On the other hand, the presence of a separate detection output 25 for providing a separate detection output signal Sd offers the possibility to provide a detection output signal Sd which is constantly active under normal circumstances, e.g. an active voltage level, wherein the detection of an event is indicated by the detection output signal Sd becoming inactive, for example the voltage level falling away. This then automatically offers a signalling of vandalism or worse if the output cables of the sense cam are cut through.

In a preferred embodiment, the sense cam 100 further comprises a passive infrared detector 27 mounted in such a way that it "sees" at least an important part of the guarded zone 3; preferably, the sensitivity area of the passive infrared detector 27 is even larger than the guarded zone 3. Since passive infrared detectors are known per se, and since the present invention can be implemented using a passive infrared detector known per se, it is not necessary here to explain the construction and functioning of a passive infrared detector. The passive infrared detector 27 provides an output signal Spir that is received by the controller 30 at a second detector input 37. Under normal circumstance, the sense cam 100 then being in a standby state, the passive infrared detector 27 has the function of a primary detector. The camera 10 does not need to function then, or may function with a low image frequency of for instance 1 image per second. When the passive infrared detector 27 detects a potential movement, for instance of a person, the passive infrared detector 27 gives a corresponding signal Spir to the controller 30. The sense cam 100 then enters an active state, in which the controller 30 gives an activation signal Cact to the camera 10 at an activation output 31. Now, the camera 10 starts to function at normal speed, and provides for instance 25 images per second, that are processed by the controller 30 in the manner described in the preceding. Also the light source 24 can now be switched on by the controller 30.

The system now functions in the way as described in the preceding. When from the image signals received from the camera 10 it proves that nothing is going on, the system switches back again to the standby state after some time. To that end, the controller 10 may cancel the activation signal Cact, or send a de-activation signal to the camera 10.

Figure 3 is a schematic perspective front view of a robust preferred embodiment of the housing 20, milled from a solid block of aluminium of approximately 13 cm high, 6 cm wide and 6 cm deep. At the front side, the housing 20 has a first opening 51 for the lens system 21 and the image sensor 22, a second opening 52 for the light detector 23, a third opening 53 for the array of LEDs 24, and a fourth opening 54 for the passive infrared detector 27. The housing 20 further has two recesses in the front side for attaching transparent cover plates, which, however, are not shown for the sake of simplicity. The housing 20 has an inner space in which, inter alia, the image sensor 22 is arranged, aligned with the lens system 21; this image sensor 22 and other electronic components are accessible through an opening in the rear surface of the housing 20, which is closed with a lid, but this is not shown for the sake of simplicity.

In the bottom surface of the housing 20, an passage opening is arranged for passing a supply input cable and one or more signal output cables. The housing 20 is provided with an attachment support that protects the cables and enables an adjustment of the housing about two mutually independent axes. An inversely U- shaped shielding hood is arranged over the housing 20; screw holes 55 serve for this attachment.

It will be clear to a person skilled in the art that the invention is not limited to the exemplary embodiments discussed in the preceding, but that several variations and modifications are possible within the protective scope of the invention as defined in the attached claims.

For example, it is possible that the controller 30 continuously provides the movement detection signal Sd after an established movement, and that it has to be reset manually by the owner or a warden, or that the controller 30 provides the movement detection signal Sd after an established movement only during a predetermined period of time, for instance an hour.

Further, it is possible that the light source 24 provides visible light. In the preceding, the present invention has been explained with reference to block diagrams illustrating functional blocks of the device according to the present invention. It should be clear that one or more of these functional blocks may be implemented in hardware, wherein the function of such functional blocks is preformed by individual hardware components, but it is also possible that one or more of these functional blocks are implemented in software, so that the function of such a functional block is performed by one or more lines of code of a computer program or by a programmable device such as a microprocessor, microcontroller, digital signal processor, etc.

Claims

1. Detection camera module (100), comprising: a housing (20) ; a camera (10) with an image sensor (22) mounted in the housing (20) for providing image signals (Sb) of a guarded zone (3) outside the housing; a controller (30) mounted in the housing (20) with an image input (32) for receiving the image signals (Sb) from the image sensor (22) ; an image output (26) for outputting image output signals (Sw) ; a detection output (25) for outputting a detection output signal (Sd) ; wherein the controller (30) is adapted to process the image signals (Sb) received at its image input (32) in order to detect a movement, and in order to generate the detection output signal (Sd) depending on the result of this movement detection.

2. Detection camera module according to claim 1, wherein the image output signals (Sw) are continuously outputted at the image output (26) , independent of the result of the said movement detection.

3. Detection camera module according to claim 1, wherein the controller (30) is adapted to only output the image output signals (Sw) after a detected movement.

4. Detection camera module (100), comprising: a housing (20) ; a camera (10) with an image sensor (22) mounted in the housing (20) for providing image signals (Sb) of a guarded zone (3) outside the housing; a controller (30) mounted in the housing (20) with an image input (32) for receiving the image signals (Sb) from the image sensor (22) ; an image output (26) for outputting image output signals (Sw) ; wherein the controller (30) is adapted to process the image signals (Sb) received at its image input (32) in order to detect a movement, and to only output the image output signals (Sw) after a detected movement.

5. Detection camera module according to any of the preceding claims, wherein the image sensor (22) is a CCD sensor, preferably suitable for providing image signals of at least 480 lines per frame and at least 640 pixels per line.

6. Detection camera module according to any of the preceding claims, wherein the image sensor (22) is a colour sensor.

7. Detection camera module according to any of the preceding claims, wherein the image sensor (22) is sensitive to infrared light, preferably with a wavelength in the range of approximately 800 nm.

8. Detection camera module according to any of the preceding claims, further provided with a light source (24) mounted in the housing (20), which light source is suitable for illuminating at least a part of the guarded zone (3) .

9. Detection camera module according to claim 8, wherein the wavelength range of the light source (24) is tuned to the sensitivity range of the image sensor (22) .

10. Detection camera module according to any of the preceding claims 1-6, wherein the image sensor (22) is sensitive to infrared light, preferably with a wavelength in the range of approximately 800 nm; wherein the device is further provided with an infrared light source (24) mounted in the housing (20), which light source is suitable for illuminating at least a part of the guarded zone (3), wherein the wavelength range of the light source (24) is tuned to the sensitivity range of the image sensor (22) .

11. Detection camera module according to claim 10, wherein the infrared light source (24) comprises an array of infrared LEDs.

12. Detection camera module according to any of the claims 8-11, wherein the light source (24) is a switchable light source, and wherein the camera device is further provided with a light intensity sensor (23) mounted in the housing (20) for measuring the level of the surrounding light, to switch on the light source (24) in relatively dark circumstances and to switch off the light source (24) in case of sufficient surrounding light.

13. Detection camera module according to claim 12, wherein the controller (30) has a detector input (33) which receives a measuring signal (Si) from the light intensity sensor (23) , and a control output (34) coupled with a control input of the light source (24), and wherein the controller (30) is adapted to provide at its control output (34) a control signal (Cir) for the light source (24) depending on the measuring signal (Si) received from the light intensity sensor (23).

14. Detection camera module according to claim 12, wherein the controller (30) has a control output (34) coupled with a control input of the light source (24), wherein the controller (30) is adapted to calculate a value for the level of the surrounding light based on the image signal (Sb) received at its image input (32), and wherein the controller (30) is adapted to provide at its control output (34) a control signal (Cir) for the light source (24) depending on the thus calculated value.

15. Detection camera module according to any of the preceding claims, further comprising a passive infrared sensor (27) mounted in the housing (20) .

16. Detection camera module according to claim 15, wherein the controller (30) has an input (37) connected to the passive infrared sensor (27) in order to receive an output signal (Spir) thereof, and wherein the controller (30) has an output (31) connected to the camera (10) in order to send an activation command (Cact) thereto.

17. Detection camera module according to claim 16, wherein the module has an active state in which the camera (10) provides camera images with a normal image frequency of for instance 25 images per second, and wherein the module has a standby state in which the camera is switched off or functions with an image frequency which is lower than the normal image frequency; wherein the module is normally in the standby state; and wherein the controller (30) is adapted, in response to receiving a detection signal (Spir) from the passive infrared sensor (27), to send the activation command (Cact) to the camera (10) in order to bring the module into the active state.

18. Detection camera module according to claim 17, wherein the controller (30) is adapted, if the image signals received from the camera (10) do not give rise to generating the detection output signal (Sd) during a predetermined period of time, to bring the module into the standby state.

19. Detection camera module according to any of the preceding claims, wherein the camera device (10) has a high-quality housing (20) which is suitable for use outdoors, and which is strong enough to be highly resistant to vandalism.