Stimulus-dependent electronic device

• US 20030114143A1
• Filed: 12/19/2001
• Published: 06/19/2003
• Est. Priority Date: 12/19/2001
• Status: Active Grant

• Current Assignee: Advanced Wireless Communications
• Original Assignee: Advanced Wireless Communications
• Inventors: Blakeley, Peter Alan, Kulseth, Paul Michael
• Granted Patent: US 7,139,560 B2
• Time in Patent Office: Days
• US Class Current: 455/410
• CPC Class Codes: H04M 1/66 with means for preventing unauthorised or fraudulent calling verifying user identity or authority in secret or secure digital communications H04L9/32
• CPC Class Codes: H04M 1/724 User interfaces specially adapted for cordless or mobile telephones

Abstract

Herein is disclosed a method, system, and apparatus for dettering theft of portable electronice devices. A portable electronic device is rendered incapable of properly operating after being powered down, without at least some exposure for some time to a given stimulus during a subsequent power-up sequence. A source of the stimulus is provided within a locality from which the devices are not to be removed. Transmission of the stimulus is limited to a region of space within the locality.

Claims

1. A two-way radio requiring a stimulus from an external source for completion of a power-up sequence, the radio comprising:

operational circuitry of the radio for reception and transmission of a radio signal;

a power source that provides power to the operational circuitry; and

a stimulus-sensitive switch interposed between the power source and the operational circuitry;

wherein, the stimulus-sensitive switch is configured to remain closed upon initial exposure to a given stimulus, until such time as the radio is powered down.

2. The radio of claim 1, further comprising:

an on/off switch interposed between the power source and the operational circuitry.

3. The radio of claim 1, wherein the stimulus-sensitive switch comprises:

a first switch that closes in response to exposure to a given stimulus; and

a second switch that closes in response to closure of the first switch.

4. The radio of claim 3, wherein closure of the second switch completes a feedback circuit causing the second switch to remain closed.

5. The radio of claim 1, wherein the stimulus-sensitive switch is configured to respond to exposure to a magnetic field.

6. The radio of claim 1, wherein the stimulus-sensitive switch is configured to respond to exposure to an infrared signal.

7. The radio of claim 1, wherein the stimulus-sensitive switch is configured to respond to exposure to a radio frequency signal.

8. A method of governing a power-up sequence of a battery-powered two-way radio, the method comprising:

(a) interrupting flow of electrical current from the battery with a non-mechanically actuatable switch; and

(b) upon initial exposure to a given stimulus, closing the switch, thereby permitting electrical current to flow from the battery and allowing the power-up sequence to take place.

9. The method of claim 8, further comprising:

(c) interrupting the flow of electrical current from the battery with a mechanically actuatable switch.

10. The method of claim 8, wherein step (b) comprises closing the switch in response to a magnetic field.

11. The method of claim 8, wherein step (b) comprises closing the switch in response to an infrared signal.

12. The method of claim 8, wherein step (b) comprises closing the switch in response to a radio frequency signal.

13. The method of claim 8, wherein step (b) comprises closing the switch in response to a sequence of magnetic pulses.

14. The method of claim 8, wherein step (b) comprises closing the switch in response to reception of an identification code modulated against a radio frequency carrier signal.

15. A method of governing use of a battery-powered two-way radio controlled by an embedded microprocessor programmed to execute a sequence of instructions for operating the radio, the method comprising:

instructing the microprocessor to enter an inactive state, upon power-up of the radio;

instructing the microprocessor to remain in the inactive state, until a particular stimulus is received, thereby rendering the radio non-operational; and

instructing the microprocessor to exit the inactive state and to execute the sequence of instructions for operating the radio, upon reception of the stimulus, thereby restoring the operation of the radio.

16. A method of deterring removal of a portable electronic device from a locality, the method comprising:

(a) rendering operation of the portable electronic device dependent upon a given stimulus, so that the device is inoperable without at least some exposure for some time to the given stimulus;

(b) providing a source of the stimulus within the locality; and

(c) limiting transmission of the stimulus to a region of space within the locality.

17. The method of claim 16, wherein step (a) comprises:

preempting a power-up sequence, until exposure to the stimulus.

18. The method of claim 16, wherein the portable electronic device is a two-way radio, and wherein step (a) comprises:

disabling reception of a radio signal, until exposure to the stimulus.

19. The method of claim 16, wherein the portable electronic device is a two-way radio, and wherein step (a) comprises:

disabling transmission of a radio signal, until exposure to the stimulus.

20. The method of claim 16, wherein the stimulus is a magnetic field.

21. The method of claim 16, wherein the stimulus is an infrared signal.

22. The method of claim 16, wherein the stimulus is an identification code modulated against a radio frequency carrier signal.

23. The method of claim 16, wherein step (a) comprises interrupting an output of a voltage regulator that powers circuitry within the portable electronic device, until exposure to the stimulus.

24. A method of deterring removal of a portable electronic device from a locality, the method comprising:

(a) rendering the portable electronic device incapable of properly operating after being powered down, without at least some exposure for some time to a given stimulus during a subsequent power-up sequence;

(b) providing a source of the stimulus within the locality; and

(c) limiting transmission of the stimulus to a region of space within the locality.

25. The method of claim 24, wherein step (a) comprises:

preempting a power-up sequence, until exposure to the stimulus.

26. The method of claim 24, wherein the portable electronic device is a two-way radio, and wherein step (a) comprises:

disabling reception of a radio signal, until exposure to the stimulus.

27. The method of claim 24, wherein the portable electronic device is a two-way radio, and wherein step (a) comprises:

disabling transmission of a radio signal, until exposure to the stimulus.

28. The method of claim 24, wherein the stimulus is a magnetic field.

29. The method of claim 24, wherein the stimulus is an infrared signal.

30. The method of claim 24, wherein the stimulus is an identification code modulated against a radio frequency carrier signal.