CREDENTIAL READER HAVING A MICRO POWER PROXIMITY DETECTOR AND METHOD OF OPERATING THE CREDENTIAL READER

• US 20090152352A1
• Filed: 12/18/2007
• Published: 06/18/2009
• Est. Priority Date: 12/18/2007
• Status: Active Grant

• Current Assignee: UTC Fire & Security Americas Corporation, Inc. (Carrier Global Corporation)
• Original Assignee: UTC Fire & Security Americas Corporation, Inc. (Carrier Global Corporation)
• Inventors: Eurich, Charles Russell, Hemmer, Steven George
• Granted Patent: US 8,167,203 B2
• Time in Patent Office: Days
• US Class Current: 235/439
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10207 parameter settings related to power consumption of the interrogator

Abstract

An improved battery-powered credential reader, which may be used in security and other applications, includes include a micro-power proximity detector. The micro-power proximity detector is configured to lengthen battery life by reducing power consumption requirements of the credential reader during periods when no credential is present. An antenna formed about a perimeter of a printed circuit board is configured to propagate an electrostatic sense field adjacent to and through the credential reader using only microamps of electrical current. A control circuit of the micro-power proximity detector is configured to activate the credential reader from a “sleep” state when a disturbance in the electrostatic sense field caused by a credential is detected and/or registered.

Claims

1. A credential reader, comprising:

a power source; and

a micro-power proximity detector coupled with the power source.

2. The credential reader of claim 1, wherein the power source comprises one or more batteries.

3. The credential reader of claim 2, wherein the micro-power proximity detector further comprises:

an antenna configured to couple with a sense field adjacent the credential reader; and

a control circuit coupled with the antenna and with the power source.

4. The credential reader of claim 3, wherein the control circuit is configured to generate the sense field with microamps of current from the power source.

5. The credential reader of claim 3, wherein the control circuit is configured to detect a disturbance in the sense field caused when an object having a virtual capacitance enters the sense field.

6. The credential reader of claim 5, wherein the disturbance is a change in an electrical charge of the sense field.

7. The credential reader of claim 6, wherein the electrical charge is a net electrical charge of the sense field.

8. The credential reader of claim 5, wherein the control circuit is configured to generate a command signal when the disturbance in the sense field is detected.

9. The credential reader of claim 8, wherein the command signal is configured to activate the credential reader from a “

sleep”

state.

10. The credential reader of claim 3, wherein the sense field is an electrostatic field.

11. A method, comprising:

generating a sense field adjacent to a credential reader;

detecting a disturbance in the sense field caused by a credential; and

generating a command signal configured to activate the credential reader from a “

sleep”

state.

12. The method of claim 11, wherein the sense field is an electrostatic sense field.

13. The method of claim 11, wherein the sense field is generated using microamps of electrical current from a power source.

14. The method of claim 13, wherein the power source is one or more batteries.

15. The method of claim 12, wherein the disturbance is a change in an electrical charge of the sense field.

16. The method of claim 15, wherein the electrical charge is a net electrical charge of the sense field.

17. A credential reader, comprising:

a printed circuit board;

an antenna formed about a perimeter of the printed circuit board and configured to couple with an electrostatic sense field

a control circuit formed on the printed circuit board, wherein the control circuit is coupled with a power source and configured to draw microamps of power from the power source to generate the electrostatic sense field, wherein the control circuit is further configured to detect and register a disturbance in the electrostatic sense field and to activate higher-power circuitry within the credential reader to read the credential when the disturbance is detected.

18. The credential reader of claim 17, wherein the antenna is configured to propagate the sense field to extend adjacent to a surface of the credential reader, and to extend into and through a local dielectric.

19. The credential reader of claim 18, wherein the local dielectric is a material that comprises a housing of the credential reader.

20. The credential reader of claim 17, wherein the disturbance in the electrostatic sense field is any change in a proximity environment that causes a change in a current flow through the electrostatic sense field.

21. A method, comprising:

detecting a disturbance in a sense field, which is generated by a micro-power proximity detector of a credential reader;

determining that no credential is present within the disturbed sense field;

one of turning off the credential reader or placing the credential reader into a “

sleep”

state; and

self-calibrating the micro-power proximity detector to account for the disturbance detected in the sense field.