Advanced inductive charging pad for portable devices

• US 8,248,024 B2
• Filed: 08/15/2008
• Issued: 08/21/2012
• Est. Priority Date: 08/15/2008
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Yuan, Tong, Yang, Xiao, Wang, Min, Zhang, Chunhui, Wang, Jian
• Primary Examiner(s): Koval, Melissa
• Assistant Examiner(s): MILLER, DANIEL R
• Application Number:
  US12/192,220
• Publication Number:
  US 20100039066A1
• Time in Patent Office: 1,467 Days
• Field of Search: 320/108
• US Class Current: 320/108
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/00302 Overcharge protection

Abstract

Systems and methodologies for efficient inductive charging of electronic devices are provided herein. A charging device as described herein can utilize a sensor-integrated resonating circuit with automatic frequency control to provide low-cost inductive charging functionality for electronic devices. As further described herein, a device to be charged can be equipped with a power receiver operable to receive power from the charging device via electromagnetic induction. The power receiver can additionally be utilized for initiation of charging such that charging for a device commences upon its associated power receiver being brought within range of an inductive charging surface at the charging device. Further, a charging device as described herein can have an inductive charging surface as well as a non-charging surface for providing other services such as information display. A charging device can integrate with an external information source to obtain items to be displayed at a non-charging surface thereon.

Claims

1. A charging unit to be used by an electronic device to charge an electronic device, the charging unit comprising:

a first outer surface comprising a charging surface;

a second outer surface and comprising a display surface, wherein the second outer surface is opposite the first outer surface such that when the charging surface is oriented upwards to receive an electronic device thereon for charging, the display surface is oriented downwards and is non-viewable;

an initialization component configured to enable a load detection component based upon detecting that the charging surface is oriented upwards, the initialization component including an orientation tracking component configured to determine whether the charging device is oriented upwards such that the at least one charging surface thereon is engageable by the electronic device, wherein the load detection component is not enabled when the orientation tracking component determines that the charging device is not oriented upwards such that the at least one charging surface thereon is engageable by the electronic device, wherein the charging unit is not capable of detecting the electronic device when the load detection component is not enabled;

the load detection component configured to detect engagement of the electronic device at the charging surface when enabled by the initialization component; and

a charging component that is configured to wirelessly provide power to an engaged device at the charging surface via electromagnetic induction when the load detection component detects the engaged device;

wherein the display surface is configured to display graphical information based on a determination by the orientation tracking component that the charging device is oriented to allow viewing of the display surface.

2. The charging unit of claim 1, wherein the initialization component further comprises a timer module configured to disable charging at the charging unit based upon determining that no device engagement has occurred at the charging device within a predetermined time period following enablement of charging.

3. The charging unit of claim 1, wherein the load detection component is configured to detect device engagement at least in part by determining whether a power receiver associated with the electronic device has been brought within inductive range of the charging surface.

4. The charging unit of claim 3, further comprising a resonating state monitor configured to determine a resonating frequency of the power receiver, wherein the charging component is configured to provide power to the associated electronic device via electromagnetic induction using the resonating frequency determined by the resonating state monitor.

5. The charging unit of claim 4, wherein the charging component comprises a switching circuit configured to facilitate periodic variance in an inductive current utilized for providing power to the associated electronic device via electromagnetic induction at the resonating frequency determined by the resonating state monitor.

6. The charging unit of claim 1, wherein the charging surface is configured to facilitate simultaneous charging of a plurality of disparate electronic devices.

7. The charging unit of claim 1, wherein the charging surface comprises a visible indicator configured to indicate that charging is occurring for one or more electronic devices.

8. The charging unit of claim 1, wherein the orientation tracking component is further configured to determine an orientation of a face of the at least one charging surface.

9. The charging unit of claim 8, wherein the orientation tracking component comprises at least one accelerometer.

10. The charging unit of claim 1, wherein the charging unit is configured to obtain information to display at the display surface.

11. A method, comprising:

activating a load detecting mode by monitoring orientation of an electronic charging pad and determining from the orientation that a charging area of the electronic charging pad is oriented upward to allow engagement of an electronic device with the charging area, the electronic charging pad comprising a display surface, wherein the display surface is opposite the charging area such that when the charging area is oriented upwards to engage the electronic device for charging, the display surface is oriented downwards and is non-viewable, the load detecting mode comprising a mode wherein the electronic charging pad is sensing for presence of an electronic device to be charged, wherein when the monitoring the orientation determines that the charging area is not oriented upward to allow engagement of the electronic device with the charging area the load detecting mode is not activated and the charging pad is not sensing for presence of the electronic device to be charged;

when the load detecting mode has been activated, detecting engagement between the charging area and at least one power receiver associated with at least one electronic device to be charged;

providing power to the at least one engaged power receiver via electromagnetic induction; and

displaying graphical information at the display surface when the monitoring the orientation determines that the electronic charging pad is oriented to allow viewing of the display surface.

12. The method of claim 11, wherein the detecting further comprises:

determining whether the power receiver is detected within a predetermined time following initialization of the load detecting mode; and

disabling the load detecting mode pending detection of a power receiver upon determining that a power receiver has not been detected within the predetermined time.

13. The method of claim 11, wherein the providing comprises:

determining a resonating frequency of an engaged power receiver; and

inductively providing power to the engaged power receiver at the determined resonating frequency.

14. The method of claim 11, further comprising disabling the load detection mode based upon detecting removal of an engaged power receiver from the charging area.

15. The method of claim 11, further comprising providing at least one visual or auditory indication that power is being provided to the at least one engaged power receiver.

16. The method of claim 11, wherein:

the detecting comprises detecting engagement between a plurality of power receivers associated with respective electronic devices and the charging area; and

the providing comprises providing power to the engaged power receivers simultaneously.

17. The method of claim 11, wherein the displaying comprises:

obtaining display information from an external information store; and

displaying the obtained display information at the display surface.

18. A charging pad for charging electronic devices, the charging pad comprising:

an inductive charging unit to charge devices placed on the charging pad, the charging pad having a first outer surface on which devices rest when being charged, the charging pad having a second outer surface comprising a display, wherein the second outer surface is opposite the first outer surface such that when the first outer surface is oriented upwards to receive an electronic device thereon for charging, the second outer surface is oriented downwards such that the display is non-viewable; and

an orientation sensor that senses the orientation of the charging pad, where the charging pad has an idle mode, a load detecting mode, and a charging mode, and where the charging pad is switched to and from the idle mode and the load detecting mode according to the orientation sensor determining that the charging pad is oriented such that the first outer surface is facing upward, and when an electronic device is placed on the charging pad while the charging pad is in the load detecting mode the charging pad enters the charging mode to charge the electronic device;

wherein the display is configured to display graphical information based on a determination by the orientation sensor that the charging pad is oriented to allow viewing of the display.