Radio based proximity token with multiple antennas

• US 6,307,471 B1
• Filed: 11/17/2000
• Issued: 10/23/2001
• Est. Priority Date: 12/01/1999
• Status: Expired due to Fees

• Current Assignee: Ensure Technologies Incorporated
• Original Assignee: Ensure Technologies Incorporated
• Inventors: Xydis, Thomas D.
• Primary Examiner(s): TRIEU, VAN THANH
• Application Number:
  US09/715,686
• Time in Patent Office: 340 Days
• Field of Search: 340/539, 340/568.1, 340/571, 340/572.1, 340/572.7, 340/10.1, 340/10.31, 340/825.34, 340/825.31, 340/573.4
• US Class Current: 340/568.1
• CPC Class Codes: G06F 21/35 communicating wirelessly
• CPC Class Codes: G07C 9/28 the pass enabling tracking or indicating presence

Abstract

A method of detecting a signal (10, 10′) between a token (12) and an electronic device (14) for authorizing a user (16) to access the electronic device (14). The method comprises the steps of emitting a signal (10, 10′) containing data, detecting the signal (10, 10′) with a plurality of antennas (18, 18′), and measuring the strength of the signal (10, 10′) detected at each of the antennas (18, 18′). If the maximum signal strength detected by any of the antennas (18, 18′) is above an operational threshold, the electronic device (14) will be enabled. If the signal (10, 10′) is above the operational threshold, the signal (10, 10′) is compared to a user code database for authorizing the user (16) to access the electronic device (14). The operational threshold may be lowered to account for any signal variances that may occur after the user (16) has been authorized to access or when accessing the electronic device (14).

Claims

1. A method of detecting a signal between a token and an electronic device for authorizing a user to access the electronic device, said method comprising the steps of;

emitting a signal (10, 10′

) containing data from at least one of a token (12) and an electronic device (14),

detecting the same signal (10, 10′

) with each of a first plurality of antennas (18, 18′

) disposed within the other of the token (12) and the electronic device (14),

measuring the strength of the same signal (10, 10′

) detected at each of the first plurality of antennas (18, 18′

) with a measurement device (20, 20′

),

sensing the maximum signal strength detected by any of the first plurality of antennas (18, 18′

), and

enabling the electronic device (14) to allow the user access in response to the maximum signal strength being above an operational threshold to overcome variances in signal strength in response to relative movement between the token (12) and the electronic device (14) to remain enabled so long as at least one antenna (18, 18′

) detects the same signal (10, 10′

) and measures the maximum signal strength above the operational threshold.

2. A method as set forth in claim 1 wherein the measuring is further characterized by scanning the first plurality of antennas (18, 18′

) for sequentially measuring the strength of the signal (10, 10′

) at each antenna and isolating the antenna measuring the maximum signal strength as a default antenna such that the default antenna is the first one of the plurality of antennas (18, 18′

) to detect the signal (10, 10′

) upon subsequent emissions.

3. A method as set forth in claim 2 further characterized by comparing the data of the signal (10, 10′

) detected at the default antenna to a user code database and enabling the electronic device (14) for authorizing a user (16) to access the electronic device (14).

4. A method as set forth in claim 3 further characterized by changing the operational threshold in response to the data of the signal (10, 10′

) matching a user code in the user code database.

5. A method as set forth in claim 4 further characterized by changing the operational threshold in response to operation of the electronic device (14) by the user (16).

6. A method as set forth in claim 4 wherein the changing of the operational threshold is further defined by lowering the operational threshold.

7. A method as set forth in claim 6 wherein the changing of the operational threshold is further defined as lowering the threshold in response to input to the computer from one of a keyboard (26) and a mouse (28).

8. A method as set forth in claim 2 further defined as emitting the signal (10, 10′

) from the electronic device (14) and measuring the strength of the signal and sensing the maximum signal strength by a token (12).

9. A method as set forth in claim 2 further defined as emitting the signal (10, 10′

) from the token (12) and measuring the strength of the signal and sensing the maximum signal strength by the electronic device (14).

10. A method as set forth in claim 2 further characterized by aiming one of the first plurality of antennas (18, 18′

) in a first direction and an other of the first plurality of antennas (18, 18′

) in a second direction, the first direction being transverse to the second direction and such that one of either the first direction and the second direction is more sensitive for detecting the signal (10, 10′

) than the other direction.

11. A method as set forth in claim 2 wherein the emitting of the signal (10, 10′

) is further defined as emitting the signal (10, 10′

) from a second plurality of antennas (19, 19′

).

12. A method as set forth in claim 11 wherein the emitting of the signal (10, 10′

) from the second plurality of antennas (19, 19′

) is further defined as alternating the emission of the signal (10, 10′

) from one of the second plurality of antennas (19, 19′

) and then from the other of the second plurality of antennas (19, 19′

).

13. A method as set forth in claim 12 including sequentially detecting each of the signals (10, 10′

) emitted from the second plurality of antennas (19, 19′

) and measuring the strength of the sequential signals (10, 10′

) with the first plurality of antennas (18, 18′

).

14. A method of detecting a signal between a token and an electronic device for authorizing a user to access the electronic device, said method comprising the steps of;

emitting a signal (10, 10′

),

detecting the signal (10, 10′

) with at least one antenna,

measuring the strength of the signal (10, 10′

) detected by the antenna,

comparing the strength of the signal (10, 10′

) to an operational threshold,

enabling the electronic device (14) to allow the user access in response to the signal strength being above the operational threshold,

changing the operational threshold in response to the user (16) manipulating the electronic device (14) such that variances in the signal strength allow the electronic device (14) to remain enabled so long as the user is using the electronic device (14),

restoring the operational threshold to the prior value before changing when the user ceases using the electronic device (14).

15. A method as set forth in claim 14 wherein the changing of the operational threshold is further defined by lowering the operational threshold.

16. A method as set forth in claim 15 wherein the enabling of the electronic device (14) is further defined as enabling a computer.

17. A method as set forth in claim 16 wherein the changing of the operational threshold is further defined as lowering the threshold in response to input to the computer from one of a keyboard (26) and a mouse (28).

18. A method as set forth in claim 14 wherein the detecting of the signal (10, 10′

) includes detecting the signal (10, 10′

) with a plurality of antennas (18, 18′

).