The present invention relates to an apparatus and method for controlling access to restricted areas using a low cost security device.

BACKGROUND OF THE INVENTION

Security is an ever present concern in today's international climate. The protection of information, equipment and personnel are an issue that faces private companies and government agencies alike. The theft of equipment alone costs millions of dollars each year. Issues of legal responsible and indemnity also have to be taken into consideration. Therefore, companies and government agencies have to protect themselves from larceny and litigation brought against them by employees and non-employees.

Security systems are often employed by organisations to restrict access to particular areas. These can be areas which contain sensitive information such as company mainframes or areas that pose a risk to life such as high voltage switchboards. One of the simplest forms these security systems comprise a motion detector connected to an alarm. When the motion detector is tripped by movement the alarm is activated. The alarm can be fitted with an audible siren and in many cases is also monitored by a security company. These types of security devices have limited usefulness and cannot be used to identify between an intruder and authorised personnel.

Some security systems employ key pads or swipe cards to allow authorised personnel into a restricted area. Other more advanced security systems utilise radio frequency (RF) technology. RF technology is used in a variety of applications including television, radar, and automatic identification systems. The term RFID (radio frequency identification) has been coined to describe the use of radio frequency signals to provide automatic identification of items. RFID technology is used in applications such as the electronic collection of road tolls and access control.

Radio frequencies range from very low frequency (VLF), which has a range of 10 to 30 kHz, to extremely high frequency (EHF), which has a range of 30 to 300 GHz. The use of radio frequencies in security system has proved to be convenient, easy to use, and well suited for automatic operation. RFID does not require contact

or line-of-sight to operate, can function under a variety of environmental conditions, and provides a high level of data integrity. The technology is also difficult to counterfeit and therefore RFlD provides a high level of security.

Radio frequency security systems typically includes a RF tag, a RF transceiver that generates the RF signals, and a reader that receives RF transmissions from a RF tag and passes the data to a host systems for processing. The RF tag can be in the form of passive tags that does not actively transmit or a transponder which actively transmit to a reader.

Radio frequency identification acts in a similar manner to bar coding. The RF tag is programmed with data that identifies the person to which the tag is attached. If a RF tag is not present and the receiver does not receive a response then the alarm will be activated. In this way RFID security system can identify between an intruder and authorised personnel. One of the limitations with this system is that radio waves must be transmitted from the transceiver constantly or at regular interval. This can increase the overall running costs of the security system and may also cause interference with other equipment.

It is an object of the present invention to provide for a security device that overcomes at least some of the aforementioned problems or provides the public with a useful alternative.

It is yet a further object of the present invention to provide for a security device that is simple to use and has low operational costs.

SUMMARY OF THE INVENTION

Therefore in one form of the invention there is proposed an apparatus for controlling access to restricted areas including: at least one detector adapted to sense motion; at least one generator that is configured to emit a signal when the motion detector sensors movement; a mobile device adapted to reflect the signal; at least one reader which receives the reflected signal from the mobile device; and at least one processor adapted to control the motion detector, generator and reader.

Preferably, the signal is a radio frequency signal.

Preferably, the apparatus includes an alarm which is activated in the event that the reader does not receive a reflected signal.

Preferably, the mobile device is a radio frequency tag.

Preferably, the radio frequency tag is passive and does not require a power source such as a battery.

Preferably, the radio frequency tag reflects or backscatters the signal emitted from the generator.

Preferably, when the generator is activated it is adapted to emit a focused beam of radio waves.

Preferably, the detector, generator, reader and alarm are hard wired to the processor.

Preferably, the detector, generator, reader and alarm are wirelessly connected to the processor

In a further form of the invention there is proposed a method for controlling access to restricted areas including the steps of: activating a motion detector; when the motion detector senses a moving object within a specified physical space a signal generator is activated; the signal generator is configured to emit a signal; if a mobile device, adapted to reflect the signal, is present on the moving object the signal is reflected back to a reader and a processor recognises the object as authorised; if the mobile device, adapted to reflect the signal, is absent on the moving object the signal is not reflected back to the reader and the processor recognises the object as unauthorised and undertakes a predetermined task.

Preferably, the signal is a radio frequency signal.

Preferably, the predetermined task of the processor is the activation of an alarm.

Preferably, the alarm emits an audible sound.

Preferably, the alarm is a monitored alarm.

Preferably, in the event that the motion detector senses a moving object and the generator is activated, the motion detector is deactivated.

Preferably, at a predetermined time after the processor recognises the object as authorised the motion detector is reactivated and the generator is deactivated.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several implementations of the invention and, together with the description, serve to explain the advantages and principles of the invention. In the drawings,

Figure 1 is a stylised flow chart of a security device embodying the present invention;

Figures 2a-2c is a stylised side view of the security device of Figure 1 during operation when an authorised person is present; and

Figures 3a-3c is a stylised side view of the security device of Figure 1 during operation when an intruder is present.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description of the invention refers to the accompanying drawings. Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts.

Illustrated in the figures is a security unit 10 for controlling access to restricted areas including a motion detector 12, a radio frequency generator 14, a radio frequency reader 16, and a processor 18. The security unit 10 contains an alarm 20 as illustrated in Figure 1. The operation of the motion detector 12, radio frequency generator 14, radio frequency reader 16 and the alarm 20 are controlled by the processor 18. It should be understood that although the components of the security

unit 10 may all be contained within a single self contained apparatus the invention is not limited to this configuration. It may be desirable to have each of the components positioned in separate locations or in fact to have multiples of each component. This may be desirable where the area to be monitored in quite large or where it is desirable to protect parts of the security unit 10 from vandalism or tampering by unauthorised persons. In such system the different components 12, 14, 16 and 20, may be hardwired or wirelessly connected to the processor 18. The alarm 20 is activated if the processor 18 determines that an intruder is present in the area of surveillance 22. It may also be desirable to configure the alarm 20 to be activated if tampering or vandalism of the security unit 10 occurs. The alarm 20 can be a monitored alarm or an alarm that emits an audible sound such as a siren. However, the skilled addressee should understand that the invention is not limited to these types of alarms. The security unit 10 may also be connected to a pre-exiting alarm system thereby minimising the cost of installation.

In a preferred embodiment, as illustrated in Figure 1 , the motion detector 12 is a passive infrared detector. During normal operation the motion detector 12 of the security unit 10 emits an infrared signal 24. If a moving object 26, such as a person, is present within the area of surveillance 22 a return signal 28 will be received by the motion detector 12. As a result the radio frequency generator 14 is activated. This activation can occur directly 30 between the detector 12 and the generator 14 or indirectly 32 via the processor 18. The security unit 10 may contain a single processor 18 as illustrated in Figure 1. Alternatively, the motion detector 12, the radio frequency generator 14 and the radio frequency reader 16 can each have a separate processor (not shown), in communication with each other, which controls their respective operation.

The activated radio frequency generator 14 emits a focused radio frequency signal 34. If the individual 26 is authorised to be within the area of surveillance 22 monitored by the security unit 10 they will have been issued with a radio frequency or RF tag 36. The RF tag 36 is configured to reflect or backscatter the signal 34 emitted from the radio frequency generator 14 to the radio frequency reader 16. The RF tag 36 can be in the form of a passive tag that does not require a power source however it should be understood that the invention is not limited to use of a passive tag. If the radio frequency reader 16 receivers a signal 38 back from the RF tag 36 then the individual 26 is recognised as being authorised to be in that particular area 22. It is

envisaged that the security unit 10 is configured so that the motion detector 12 remains inactive whilst the radio frequency generator 14 is operating. The motion detector 12 is then reactivated 40 when the individual 26 is recognised as being authorised.

If a signal is not received 42 by the RF reader 16 then an alarm 20 is activated. The alarm 20 is activated by the processor 18 when it is determined 44 that the reader 16 has not received a signal 42. The skilled addressee should however understand that the radio frequency reader 16 could be configured to directly contact the alarm 20. It is envisaged that the alarm 20 emits an audible sound such as a siren when activated. It may also be desirable to have a monitored alarm which is in communication with a host security system (not shown). This may be important where it is imperative to detained or at least confirm the identity of the intruder or where an unauthorised person may require assistance, for example an Alzheimer patients in a hospital.

To further illustrate the present invention Figures 2a-2c illustrate the situation when an authorised person 46 enters an area of surveillance 22 monitored by the security unit 10. The motion detector 12 contained within the security unit 10 emits an infrared signal 24. When the authorised person 46 enters the area of surveillance 22 monitored by the security unit 10 the motion detector 12 sensors the movement. The radio frequency generator 14 contained within the security unit 10 is then activated and the motion detector 12 is deactivated. The radio frequency generator 14 is configured to emit a focused radio frequency signal 34 as illustrated in Figure 2b. The authorised person 46 possesses a RF tag 36 which is configured to reflect or backscatter 38 the radio frequency signal 34 as illustrated in Figure 2c. The security unit 10 then recognises the individual 46 as authorised to be within the area of surveillance 22 monitored by the security unit 10. At a predetermined time thereafter the motion detector 12 is reactivated.

Figures 3a-3c illustrate the situation when an intruder 48 enters an area of surveillance 22 monitored by the security unit 10. The motion detector 12 contained within the security unit 10 emits an infrared signal 24. When the intruder 48 enters the area of surveillance 22 monitored by the security unit 10 the motion detector 12 sensors the movement. The radio frequency generator 14 contained within the security unit 10 is then activated and the motion detector 12 is deactivated. The radio frequency generator 14 is configured to emit a focused radio frequency signal

34 as illustrated in Figure 3b. The intruder 48 does not posses a RF tag 36 and therefore the signal 34 is not reflect. When the reader 16 does not receive a return signal 42 within a set time the processor 18 determines that the moving object is an intruder 48 and is not authorised to be within the restricted area 22. The processor 18 then activates an alarm 20. The alarm 20 is contained within the security unit 10 and when activated emits an audible sound 50 such as a siren. It should however be appreciated that the alarm 20 may be separate from the security unit 10. Furthermore, in particular circumstances it may be desirable to have an alarm that does not emit an audible sound but rather is configured to emit a signal to a monitoring system to covertly identify the presence of an intruder 48.

The skilled addressee will now appreciate the many advantages of the present invention for controlling access to restricted areas. The use of both a motion detector 12 and radio frequency technology provides a cost effect and simple method of controlling access to restricted areas. Motion detectors have lower operation costs than RF apparatus and therefore because the motion detector is used most of the time the overall operational cost of the security unit 10 is reduced. Furthermore, expensive key pads and swipe card technology with associated infrastructure are not required. Radio frequency security technology is automatic and does not require an interface such as a key pad for an authorised person to use. It is therefore a simple system to use and does not require constant input from authorised personnel. It should however be appreciated that the invention is not limited to the use of RF technology, any type of signal could be used without deviating from the scope of the invention. As the skilled addressee will now appreciate the invention would be very useful in situations where authorised personnel are passing through restricted areas on regular occasions or where they are unable to enter details into a key pad either because of physical impairment or because they are carrying a load. The security unit 10 can be configured to utilise a pre-existing alarm system and may be integrated into a monitored alarm system where it is imperative to detained or at least confirm the identity of the unauthorised entry. The system, for example, would be useful in hospitals where patients such as those suffering from Alzheimer's disease may require assistance.

Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred

embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.

In any claims that follow and in the summary of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprising" is used in the sense of "including", i.e. the features specified may be associated with further features in various embodiments of the invention.