Detection device

Abstract

A device for the detection of an open and unattended closure of an enclosure to prevent theft comprises a detector adapted to detect if the closure is open and a detector adapted to detect if the closure is unattended, the detectors being operably connected to an effector adapted to alert a user to the open and unattended condition of the closure.

Claims

1. A device for the detection of an open and unattended closure of a medical storage enclosure to prevent theft, comprising: a detector adapted to detect if the closure is open and a detector adapted to detect if the closure is unattended, the detectors being operably connected to an effector adapted to alert a user to the open and unattended condition of the closure after a predetermined period of time, and wherein the detector is adapted to monitor light and movement at the opening of the medical storage enclosure.

2. The device of claim 1, wherein the detector adapted to detect if the closure is open is also adapted to turn the device on upon opening of the closure and off when the closure is returned to a shut position.

3. The device of claim 2, wherein the detector adapted to detect if the closure is unattended is also adapted to turn the device off for a pre-determined period of time when actuated by the proximity of a user, or to actuate the effector if the proximity of a user is not detected.

4. The device of claim 3, wherein the effector adapted to alert a user to the open and unattended condition of the closure is also adapted to deactivate if the detector adapted to detect if the closure is open detects that the closure has been returned to a shut position, or if the detector adapted to detect if the closure is unattended detects the proximity of a user.

5. The device of claim 3, wherein the length of the pre-determined period of time is variable by a user.

6. The device according to claim 1, wherein the detector adapted to detect if the closure is open is a light detector adapted to activate the device by the presence of light and deactivate the device in darkness.

7. The device according to claim 1, wherein the detector adapted to detect if the closure is open is a magnetic switch adapted to activate by the opening of the closure and deactivate when the closure is returned to a shut position.

8. The device according to claim 1, wherein the detector adapted to detect if the closure is open comprises both a magnetic switch and a light detector which are adapted to activate in series or parallel upon opening of the closure and deactivate when the closure is returned to a shut position.

9. The device according to claim 1, wherein the detector adapted to detect if the closure is open is adapted to activate and deactivate by accessing a manual or electronic lock.

10. The device of claim 1, wherein, the detector adapted to detect if the closure is unattended is a passive infrared proximity sensor.

11. The device of claim 10, wherein the range of the proximity sensor can be varied.

12. The device of claim 1, wherein the effector adapted to alert a user to the open and unattended condition of the closure is an audio alarm.

13. The device of claim 1, wherein the effector adapted to alert a user to the open and unattended condition of the closure is a visual alarm.

14. The device of claim 1, wherein the effector adapted to alert a user to the open and unattended condition of the closure is both an audio and visual alarm.

15. The device of claim 1, wherein the effector adapted to alert a user to the open and unattended condition of the closure remotely activates an alarm.

16. The device of claim 1, wherein once the effector adapted to alert a user to the open and unattended condition of the closure is activated it produces an intermittent crescendo alarm between a minimum and maximum setting.

17. The device of claim 16, wherein the minimum and maximum settings of the device are variable.

18. The device of claim 16, wherein the effector adapted to alert a user to the open and unattended condition of the closure produces a continuous alarm after the maximum setting of the crescendo alarm is reached.

19. The device of claim 1, wherein the effector adapted to alert a user to the open and unattended condition of the closure automatically closes the closure when activated.

20. The device of claim 19, wherein the device further comprises a manual or electronic lock for automatically locking the closure upon closure.

21. The device of claim 1, wherein the effector adapted to alert a user to the open and unattended closure provides an alarm having a frequency of between 15 and 20 kHz.

22. The device of claim 1, further comprising a video and/or audio recording system.

23. The device of claim 22, wherein deactivation of the detector adapted to detect if the closure is unattended activates the video and/or audio recording system.

24. The device of claim 23, wherein the video and/or audio recording system is external to the device.

25. The device of claim 1, further comprising a keyless operating system.

26. The device of claim 25, wherein the device functions under normal conditions in the presence of a keyless authorization pass and emits a continuous alarm at the maximum setting if the closure is opened by a user without a keyless authorization pass.

27. The device of claim 26, wherein the device functions under normal conditions in the presence of at least two keyless authorization passes.

28. The device of claim 1, wherein the device further comprises a tamper alarm system.

29. The device of claim 28, wherein the tamper alarm system comprises light sensitive, physical or magnetic switches.

30. The device of claim 1, further comprising a securing cradle into which the detection device has been slidably fitted in a removable manner, wherein the securing cradle is attached to a surface inside the medical storage enclosure.

31. A detection device according to 30, wherein the detection device is a medical storage enclosure detection device.

32. A detection device according to 31, wherein the medical storage enclosure is a drug cabinet or drug trolley.

33. A detection device according to claim 30, wherein the detection device is reversibly releasable from the securing cradle.

34. The device of claim 1, wherein the detector adapted to detect if the closure is open is a relative light sensor for detecting opening of the closure in low light environments.

35. The device of claim 1, wherein the closure is a closure to a drug cabinet or drug trolley.

36. A medical storage enclosure detection device comprising at least one detector and an alarm, wherein the detector is adapted to detect if the medical storage enclosure is open and unattended, wherein the detection device is reversibly securable to the medical storage enclosure, further comprising a securing cradle into which the detection device has been slidably fitted in a removable manner, wherein the securing cradle is attached to a surface inside the medical storage enclosure.

37. A detection device according to claim 36, wherein the at least one detector is a light detector.

38. A detection device according to claim 37, wherein the detection device further comprises a passive infrared detector.

39. A detection device according to claim 38, wherein the passive infrared detector is adapted to detect if the medical storage enclosure is unattended.

40. A detection device according to claim 37, wherein the light detector is adapted to detect if a medical storage enclosure is open.

41. A detection device according to claim 40, wherein the light detector is also adapted to turn the device on upon opening of the closure and off when the closure is returned to a shut position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

(2) FIG. 1 is a flow chart of the alarm system according to an embodiment of the invention; and

(3) FIGS. 2A, 2B, and 2C show a schematic representation of a circuit board for the alarm system of FIG. 1.

DETAILED DESCRIPTION

(4) Referring to the drawings, there is illustrated a device for the detection of an open and unattended closure of an enclosure to prevent theft, comprising: a detector adapted to detect if the closure is open (1) and a detector adapted to detect if the closure is unattended (4), the detectors being operably connected to an effector adapted to alert a user to the open and unattended condition of the closure (5).

(5) The alarm is on standby when the door to an enclosed space is closed. Upon opening of the door, the device detects light and movement. The detection of such light and movement causes a timer to be activated for a pre-determined period of time. After the pre-determined period of time has elapsed, an intermittent crescendo alarm is initiated, which increases in volume between a minimum and a maximum setting. Once the crescendo sequence is complete, the device emits a continuous loud alarm. The alarm may be switched off, either by closing the door such that the device is in darkness, or by detecting movement, for example, near the proximity of the door. In the situation where the device detects movement, the device is turned off for a pre-determined period of time and the timer is reset. Advantageously, the device of the present invention continually monitors and detects light and movement. In one embodiment, when the device is switched off and in the stand-by configuration, the detection of movement causes the timer to be reset. In one embodiment, the pre-determined period of time in which the timer is activated is two minutes. In another embodiment, the activated timer may be reset, for example, after detecting movement.

(6) The skilled person would understand that the present invention may be embodied in a number of different ways. The following example illustrates one way in which the present invention can be successfully embodied.

(7) FIGS. 2A, 2B and 2C show a schematic for the circuit board of one embodiment of the invention. In FIG. 2A, the analogue response of the light sensitive diode (designated LED 1 and 2 on the schematic) (1) is converted into a digital signal by means of a voltage divider involving resistors R1, R15 and 16. As this is under power continuously, it is an extremely high resistance circuit to minimise standby current consumption and, as such, two light sensitive diodes in series have been incorporated to increase the sensitivity to light.

(8) R1 is a variable resistor which will allow the light sensitivity to be adjusted. This circuit is an absolute light intensity switch, however, in another embodiment the light intensity switch could be converted to a relative light intensity switch by placing a further light sensitive diode between R1 and R15 and placing this on the outside of the enclosure. Neither this nor the second light sensitive diode designated LED 2 have been included, and have been shorted across with a wire link.

(9) The output of this potential divider has been fed to the input of a 40106 NOT gate (U1a). As such, as the light intensity on LED 1 rises, its resistance falls, the potential difference on the input of this gate rises and when it reaches its threshold value, the NOT gate flips state (from ON to OFF). A second NOT gate (U1b) reverses this state such that it is off when the LED1 is in darkness.

(10) These NOT gates are Schmitt Trigger circuits and, as such, exhibit hysteresis behaviour, which in practice means that the light intensity required to turn on the alarm is higher than that needed to turn it off. In other words, as cupboards at night are often opened in lighter areas and can be moved to darker areas, the alarm may still be active.

(11) The output of U1b is fed into a BC547 NPN transistor Q2. The output of this is fed into a 5 v voltage regulator U3 such that a constant 5 v output is delivered. This is suitable for the supply of the TTL PIR (Position Infrared) module (4), and also remains constant as the battery voltage begins to fall. The output of this is used to power the integrated circuits for the next part of the circuit (termed +5 v on the schematic).

(12) FIG. 2B shows a timer circuit (2) based on 2 Schmitt Trigger NAND gates (U4a and U4b) in conjunction with a capacitor (C7) and resistors R6 and R12 the latter components determining the time delay. The variable resistor R6 allows the time interval to be varied from a minimum which is determined by R12.

(13) The timer (2) is activated when input B of U4a is momentarily connected to earth using transistor Q6 as a switch. This occurs when the circuit is powered up, by means of capacitor C18. One problem with this circuit is that retriggering (i.e. restarting the timer (2) before it has completed) is unreliable. Retriggering is enabled by means of transistor Q3 which discharges capacitor C7 through resistor R14. The output is inverted by U4c and is one of two inputs to the U4d. The PIR module (4) is also powered by the voltage regulator and the output of this is the second input to U4d. The output of the (4) module is also connected to the base of transistors Q3 and Q6 thus resetting the timer (2) as described above. As the PIR module (4) used here is a TTL device the output is tied to the 5 v supply by means of a resistor (R7) such that it becomes compatible with the CMOS circuitry.

(14) The output of U4d is used (via transistor Q5 as a switch) to power the next part of the circuit, which is the audio generating circuitry (5), as shown in FIG. 2C. This output is termed 5 v output on the schematic.

(15) The audio generating circuitry (5) is based around 3 Schmitt Trigger NOT gate oscillators (U6a, U6b and U6f) which provide the rate of crescendo, the interval of beeps and the frequency of sound, respectively.

(16) The first oscillator based around the U6a oscillator provides a square wave with a frequency adjustable via R2 from a minimum frequency determined by R. This provides a clock input to the decade counter 4017 (U5). This arrangement provides the volume crescendo mechanism as each of the ten outputs connects to the next resistor in a series of nine resistors. This means that, with each input pulse from U6a the output passes through a sequentially smaller resistance i.e., output 0 through 9 resistors output 1 through 8 and so on until it reaches the final output (labelled out 9 on the schematic) where there is no resistor and hence the sound will be loudest. Ordinarily the sequential output would simply begin again, but to keep the output on this level this output is connected to the clock enable input which holds the output on that level.

(17) To ensure the sequence always starts on the first output (labelled out 0 on the schematic) a capacitor (C15) provides a momentary pulse to the reset connector when this part of the circuit receives power. The circuit then creates a stepwise increasing voltage which is held at the maximum value.

(18) To create a series of short beeps, a second oscillator (based around U6b) creates a further higher frequency (again adjustable) square wave which switches the sound on and off at the transistor Q1. In this embodiment, the sound may then be on for an equal time to that which it is off, i.e., a rather long beep which would be shortened by means of capacitor C14. The resulting exponentially decaying voltage is converted to a clean square wave by means of 2 NOT gates (U6c and U6d) in series. The final output (labelled out 9, as described above) switches on the sound by means of transistor Q4.

(19) To create the high frequency square wave required to drive the piezoelectric transducer, the third oscillator (based on U6f as described above) delivers this via transistor Q150. This sound is amplified via an inductor coil (L1) placed across the piezoelectric element.

(20) A low battery indicator (3), as shown in FIG. 2B, is present based on a potential divider of R40 and R41 placed across the output of transistor Q2. This means that this part of the circuit is only drawing current when the enclosure is open. In one embodiment, the circuit is designed to flash a light (LED 40). An alternative embodiment comprises a circuit which is designed to have an intermittent beep sounding.

(21) This circuit is designed with maximum user simplicity in mind such that the device can simply be attached to a drug trolley without requiring further accessories, expense or training.

(22) In a further embodiment, the device may be configured to trigger a closed circuit camera, either in the immediate vicinity of the device, or as part of a system. In this setting, the output of the timer (i.e. the output of U4c), which is connected to connector PLS, could be used via an optical isolator to trigger the camera.

(23) In this embodiment, the camera would be activated for two minutes when the drug trolley is opened, and for a further two minutes every time the PIR detector (4), as shown in FIG. 2B, detects movement. In other words, when someone approaching the trolley inactivates the audible alarm, their presence will activate the closed circuit camera. In one embodiment, such a closed circuit camera may be used with closed circuit television (CCTV).

(24) Similarly, in another embodiment, the system could be modified such that a keyless operating system could be incorporated such that proximity to a pass holder would cause the alarm to operate in a manner as described above. If an unauthorised person approached the device, an immediate loud and constant alarm will result. For certain situations, for example controlled drug cupboards where two practitioners are required, the system may be configurable to require two proximity passes to achieve the normal functioning of the device.

(25) In yet another embodiment, a tamper alarm system may be integrated into the device. The tamper alarm system may consist of light sensitive, physical or magnetic switches designed to elicit a constant maximal volume alarm if the unit is removed or tampered with. A cradle may be firmly attached to the wall of the drug cabinet or trolley into which the alarm unit has been fitted in a removable manner, which inactivates the tamper alarm when the device is in situ.

(26) Additionally, in any of the stated embodiments, the device may have a hardwired battery, such that when this is exhausted a replacement device may easily be slid into place on the cradle. Since the cradle would be firmly adhered to the trolley, if the device has been removed, it will be very clear from the empty cradle.