System for protection of goods against theft

• US 5,714,933 A
• Filed: 01/11/1996
• Issued: 02/03/1998
• Est. Priority Date: 01/10/1995
• Status: Expired due to Term

• Current Assignee: SGS Thomson Microelectronics SA (STMicroelectronics NV)
• Original Assignee: SGS Thomson Microelectronics SA (STMicroelectronics NV)
• Inventors: Le Van Suu, Maurice G.
• Primary Examiner(s): SWANN III, GLEN R
• Application Number:
  US08/584,021
• Time in Patent Office: 754 Days
• Field of Search: 340/539, 340/531, 340/568, 340/669, 340/689, 340/538
• US Class Current: 340/568.1
• CPC Class Codes: G08B 13/1436 with motion detection

Abstract

A system for protection of goods against theft includes a control unit and protection modules associated with the goods, the control unit including cordless communication means and the protection modules including movement detection circuitry to find out whether the goods are being handled, and cordless communications circuitry to send an alarm message to the control unit if a movement is detected.

Claims

1. A system for protection of goods against theft comprising a control unit and protection modules associated with the respective goods, the control unit comprising cordless communications means and the protection modules comprising movement detection means to determine when the respective goods are being moved, and cordless communications means to send an alarm message to the control unit when movement of the respective goods is detected wherein the control unit and the protection modules each comprises means for communicating through a fixed communications medium;

and

wherein, following reception of the alarm message from a protection module, the control unit sends a message by RF means requesting confirmation of the alarm message through the fixed communications medium.

2. A system according to claim 1, wherein the cordless communications means of the control unit and of the protection modules are RF communications means.

3. A system according to claim 1, wherein the protection modules send an alarm message to the control unit, simultaneously through the cordless communications means and through the fixed communications medium, when movement of the respective goods with which each protection module is associated is detected.

4. A system according to claim 1, wherein, when there is no confirmation of the alarm message received through the fixed communications means, the control unit sends a request, by RF means, after a certain period of time, for a confirmation of the alarm message by RF means.

5. A system according to claim 1, wherein the fixed communications medium is an electrical power distribution system.

6. A system according to claim 1, wherein the protection modules each comprises an interface to deactivate the respective protection module.

7. A system according to claim 1, wherein each protection module comprises infrared communications means.

8. The system according to claim 1, wherein the protection module sends the confirmation through the fixed communications medium.

9. The system according to claim 1, further comprising an IR receiver coupled to the fixed communications medium;

and

wherein the cordless communications means in the protection modules includes an IR transmitter.

10. A method for protecting an item from unauthorized movement, the method comprising steps of:

(a) detecting movement of the item;

(b) when movement of the item is detected, sending an alarm message via cordless communications;

(c) when the alarm message is received via cordless communications, sending a request for a confirmation of the alarm message and requesting that the confirmation be sent via a fixed communications medium; and

(d) when the confirmation has not been received via the fixed communication medium, determining that the item has been moved without authorization.

11. The method as recited in claim 10, wherein step (d) includes a step of:

waiting a predetermined amount of time after the request for the confirmation has been sent in step (c) before determining that the item has been moved without authorization.

12. The method as recited in claim 10, wherein step (c) includes a step of:

sending the request for the confirmation of the alarm message via cordless communications.

13. The method as recited in claim 10, further comprising steps of:

receiving the request for confirmation; and

sending the confirmation via the fixed communications medium.

14. The method as recited in claim 10, wherein step (d) comprises steps of:

waiting a predetermined amount of time after the request for confirmation has been sent; and

when the predetermined mount of time has passed and no confirmation has been received via the fixed communications medium, sending a new request for the confirmation to be sent via cordless communications.

15. A method for protecting an item from unauthorized movement, the method comprising steps of:

(a) detecting when the item is moved;

(b) when the item has been moved, sending an alarm message via cordless communications; and

(c) when the alarm message has been received, sending a request for a confirmation of the alarm message and requesting that the confirmation be sent via a fixed communications medium.

16. The method as recited in claim 15, further comprising steps of:

(d) sending the confirmation via the fixed communications medium; and

(e) receiving the confirmation via the fixed communications medium.

17. The method as recited in claim 16, further comprising a step of:

repeating steps (d)-(e) a predetermined number of times.

18. The method as recited in claim 15, further comprising a step of:

(d) when the confirmation has not been received via the fixed communications medium, determining that the item has been moved without authorization.

19. The method as recited in claim 18, wherein step (d) includes a step of:

waiting a predetermined amount of time after the request for confirmation has been sent in step (c) before determining that the item has been moved without authorization.

20. A method for determining whether or not an item has been improperly moved in a system including a control unit and a protection module coupled to the item, the control unit coupled to the protection unit via a fixed communications medium, the control unit including a first cordless communications device and the protection module including a second cordless communications device and a motion detector, the method comprising steps of:

detecting movement of the item by the motion detector; and

the protection unit sending an alarm message to the control unit via the second cordless communications device; and

the control unit receiving the alarm message and sending a request to the protection unit to send a confirmation via the fixed communications medium.

21. The method as recited in claim 20, further comprising steps of:

the protection unit sending the confirmation to the control unit via the fixed communications medium; and

upon receipt of the confirmation, the control unit determining that the item has not been improperly moved.

22. The method as recited in claim 20, further comprising a step of:

when the control circuit does not receive the confirmation via the fixed communications medium, the control unit determining that the item has been improperly moved.

23. The method as recited in claim 22, further comprising a step of:

the control unit waiting a predetermined period of time after sending the request for confirmation before determining whether or not the confirmation has been received.