Portable security system using communicating cards

• US 5,396,218 A
• Filed: 07/23/1993
• Issued: 03/07/1995
• Est. Priority Date: 07/23/1993
• Status: Expired due to Fees

• Current Assignee: Valert Inc.
• Original Assignee: George Olah
• Inventors: Olah, George
• Primary Examiner(s): Coles, Sr., Edward L.
• Assistant Examiner(s): LEE, CHEUKFAN
• Application Number:
  US08/095,227
• Time in Patent Office: 592 Days
• Field of Search: 340/571, 340/572, 340/573, 340/539, 340/825.54, 340/825.44, 340/825.3, 340/825.36, 340/825.52, 340/825.07, 340/825.08, 355/100, 355/38.2, 342/45
• US Class Current: 340/568.7
• CPC Class Codes: G08B 13/1427 with transmitter-receiver for distance detection
• CPC Class Codes: G08B 21/0227 System arrangements with a plurality of child units
• CPC Class Codes: G08B 21/023 Power management, e.g. system sleep and wake up provisions

Abstract

A portable security system is based on maintaining wireless communication between two or more plastic cards within a defined range. In the simplest form, a first card intermittently transmits an identification code to a second card. The second card compares that code with a code in an internal register, and on matching those codes, transmits a return code to the first card. The first card compares the return code with a code in an internal register, and on matching those codes, resets a timer. If the timer is not reset during a defined number of transmissions by the first card, an alarm circuit is activated. One card is attached to a valuable object such as a wallet on the person, and the other card is placed elsewhere on the person; theft of the object from the person results in activation of the alarm circuit. In an advanced form, a master card communicates with a series of slave cards; each of the slave cards is attached to a different valuable object on the person.

Claims

1. A portable security system comprising a pair of cards adapted for wireless communication with each other, each card being sized sufficiently small as to be capable of being accommodated within a card compartment of a wallet and having a plastic body housing:

(a) a memory holding a digital identification code for identifying the card;

(b) a carrier signal generator;

(c) modulation means for modulating the carrier signal with the identification code in the memory;

(d) an antenna;

(e) a transmitter connected to the antenna for intermittently transmitting the modulated carrier signal to the other card;

(f) a receiver connected to the antenna for intermittently receiving a modulated carrier signal from the other card;

(g) demodulation means for demodulating the carrier signal to obtain a digital code carried in that signal; and

,

(h) a comparator means for determining if a correspondence exists between the identification code in the memory and the digital code carried in the modulated carrier signal received from the other card;

a first one of the cards also housing an alarm means;

whereby, within a defined communication range, a modulated carrier signal intermittently transmitted by the first card is adapted to create a correspondence in the comparator means on the other card, whereby on creation of such correspondence the other card is adapted to transmit a return modulated carrier signal to the first card, whereby the return modulated carrier signal is adapted to create a correspondence in the comparator means on the first card, and whereby the alarm means on the first card is actuated if such correspondence is not created in the comparator means on the first card after a defined number of transmissions of the modulated carrier signal by the first card.

2. A portable security system as in claim 1, wherein at least one of the cards is less than 2 millimeters thick.

3. A portable security system as in claim 1, wherein at least one of the cards is less than 2 millimeters thick, less than 60 millimeters high, and less than 90 millimeters wide.

4. A portable security system as in claim 1, wherein the other card is a credit card or a debit card.

5. A portable security system as in claim 1, wherein the defined communication range is approximately three meters.

6. A portable security system as in claim 1, wherein the modulated carrier signal that is transmitted by the first card is transmitted approximately every half second.

7. A portable security system as in claim 1, wherein the defined number of intermittent transmissions is four.

8. A portable security system as in claim 1, wherein a microprocessor performs the functions of the memory, the modulation means, the demodulation means, and the comparator means.

9. A portable security system as in claim 1, wherein the carrier signal has a frequency of 134 kilohertz.

10. A portable security system as in claim 1, wherein the memory holds 32 bits of identification code.

11. A portable security system comprising a series of cards, a first one of the cards adapted for wireless communication with the other cards, each card being sized sufficiently small as to be capable of being accommodated within a card compartment Of a wallet and having a plastic body housing:

(a) a memory holding one or more digital identification codes for identifying the card;

(b) a carrier signal generator;

(c) modulation means for modulating the carrier signal with the one or more identification codes in the memory;

(d) an antenna;

(e) a transmitter connected to the antenna for intermittently transmitting the modulated carrier signal;

(f) a receiver connected to the antenna for intermittently receiving a modulated carrier signal;

(g) demodulation means for demodulating the carrier signal to obtain a digital code carried in that signal; and

,

(h) a comparator means for determining if a correspondence exists between one of the one or more identification codes in the memory and the digital code carried in the received modulated carrier signal;

the first card also housing an alarm means;

whereby, within a defined communication range, a modulated carrier signal intermittently transmitted by the first card is adapted to create a correspondence in the comparator means on each of the other cards, whereby on creation of such correspondence on each other card that other card is adapted to transmit a return modulated carrier signal to the first card, whereby each of the return modulated carrier signals is adapted to create a correspondence in the comparator means on the first card, and whereby the alarm means on the first card is actuated if such correspondence is not created in the comparator means on the first card by each of the return modulated carrier signals after a defined number of transmissions of the modulated carrier signal by the first card.

12. A portable security system as in claim 11, wherein at least one of the other cards is less than 2 millimeters thick.

13. A portable security system as in claim 11, wherein at least one of the other cards is less than 2 millimeters thick, less than 60 millimeters high, and less than 90 millimeters wide.

14. A portable security system as in claim 11, wherein at least one of the other cards is a credit card or a debit card.

15. A portable security system as in claim 11, wherein the defined communication range is approximately three meters.

16. A portable security system as in claim 11, wherein the modulated carrier signal that is transmitted by the first one of the cards is transmitted approximately every 0.1 seconds.

17. A portable security system as in claim 11, wherein the defined number of intermittent transmissions is four.

18. A portable security system as in claim 11, wherein a microprocessor performs the functions of the memory, the modulation means, the demodulation means, and the comparator means.

19. A portable security system as in claim 11, wherein the carrier signal has a frequency of 134 kilohertz.

20. A portable security system as in claim 11, wherein each digital identification code is 32 bits long.

21. A portable security system comprising a series of cards, a first one of the cards adapted for wireless communication with the other cards, each card being sized sufficiently small as to be capable of being accommodated within a card compartment of a wallet and having a plastic body housing:

(a) a memory holding one or more digital identification codes for identifying the card;

(b) a carrier signal generator;

(c) modulation means for modulating the carrier signal with the one or more identification codes in the memory;

(d) an antenna;

(e) a transmitter connected to the antenna for intermittently transmitting the modulated carrier signal;

(f) a receiver connected to the antenna for intermittently receiving a modulated carrier signal;

(g) demodulation means for demodulating the carrier signal to obtain a digital code carried in that signal; and

,

(h) a comparator means for determining if a correspondence exists between one of the one or more identification codes in the memory and the digital code carried in the received modulated carrier signal;

the first card also housing an alarm means;

each of the other cards also housing an activation switch and not being in communication with the first card until the activation switch on the particular other card is activated, the first card being adapted to be made aware of which of the other cards have been so activated;

whereby, within a defined communication range, a modulated carrier signal intermittently transmitted by the first card is adapted to create a correspondence in the comparator means on each of those other cards which are activated, whereby on creation of such correspondence on each of those activated other cards each such activated other card is adapted to transmit a return modulated carrier signal to the first card, whereby each of the return modulated carrier signals is adapted to create a correspondence in the comparator means on the first card, and whereby the alarm means on the first card is actuated if such correspondence is not created in the comparator means on the first card by each of the return modulated carrier signals after a defined number of transmissions of the modulated carrier signal by the first card.

22. A portable security system as in claim 21, wherein at least one of the other cards is less than 2 millimeters thick.

23. A portable security system as in claim 21, wherein at least one of the other cards is less than 2 millimeters thick, less than 60 millimeters high, and less than 90 millimeters wide.

24. A portable security system as in claim 21, wherein at least one of the other cards is a credit card or a debit card.

25. A portable security system as in claim 21, wherein the defined communication range is approximately three meters.

26. A portable security system as in claim 21, wherein the modulated carrier signal that is transmitted by the first one of the cards is transmitted approximately every 0.1 seconds.

27. A portable security system as in claim 21, wherein the defined number of intermittent transmissions is four.

28. A portable security system as in claim 21, wherein a microprocessor performs the functions of the memory, the modulation means, the demodulation means, and the comparator means.

29. A portable security system as in claim 21, wherein the carrier signal has a frequency of 134 kilohertz.

30. A portable security system as in claim 21, wherein each digital identification code is 32 bits long.