Magnetic shield for use in a location sensing system

• US 7,916,501 B2
• Filed: 04/05/2010
• Issued: 03/29/2011
• Est. Priority Date: 12/28/2006
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Hauck, Karl P., Free, M. Benton, Geaghan, Bernard O., Libbey, Albert H., Weaver, Billy Lee
• Primary Examiner(s): Levi; Dameon E
• Application Number:
  US12/754,113
• Publication Number:
  US 20100188832A1
• Time in Patent Office: 358 Days
• Field of Search: 361/753, 361/799, 361/800, 361/816, 361/818, 178/18.07, 345/173, 174/350, 174/377
• US Class Current: 361/816
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/046 by electromagnetic means
• CPC Class Codes: H05K 9/0075 Magnetic shielding materials

Abstract

An energy transfer apparatus with a magnetic shield is configured to magnetically couple energy from a fixed location to a mobile or moveable device within a field-activated space of the energy transfer apparatus. Apparatuses include a location sensing surface and a drive coil arranged in relation to a periphery of the location sensing surface. A magnetic shield plate is disposed below the location sensing surface and the drive coil. The shield plate includes a number of radially oriented slots originating at, and distributed about, a periphery of the shield plate.

Claims

1. An apparatus, comprising:

a location sensing surface;

a drive coil disposed about a periphery of the location sensing surface; and

a magnetic shield plate disposed below the location sensing surface and the drive coil, the shield plate comprising a plurality of radially oriented slots originating at, and distributed about, a periphery of the shield plate,

wherein at least some of the slots are curved.

2. The apparatus of claim 1, wherein the shield plate is fabricated from a ferrous metal.

3. The apparatus of claim 1, wherein the shield plate is fabricated from steel.

4. The apparatus of claim 1, wherein the drive coil is arranged in a substantially circular or rectangular shape.

5. The apparatus of claim 1, wherein the shield plate comprises a bent portion extending along the periphery of the shield plate.

6. The apparatus of claim 1, wherein the shield plate comprises at least one pattern of slots arranged near the drive coil and oriented parallel to the drive coil.