Balanced magnetic array

Patent metadata

Field	Value
Publication number	US-9384881-B2
Application number	US-201414491583-A
Country	US
Kind code	B2
Filing date	Sep 19, 2014
Priority date	Sep 19, 2014
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

A balanced magnetic string and methods for forming same are described. The balanced magnetic string includes at least a plurality of magnetic elements linearly arranged in an alternating magnetic polarity pattern and each comprising a first magnetic volume and a compensating magnetic element having a second magnetic volume that is different than the first magnetic volume. The plurality of magnetic elements and the compensating magnetic element magnetically interact to provide a resultant magnetic field having a desired magnetic field strength at a point of interest.

First claim

What is claimed is:

1. A balanced magnetic array having m magnetic elements, comprising:
a linear array of magnetic elements corresponding to a magnetic string comprising:
m−1 magnetic elements, arranged in an alternating magnetic pattern wherein each of the m−1 magnetic elements comprises a magnetic volume Vm and each located a distance x i from a point of interest; and
an m th magnetic element comprising a magnetic property such that a magnetic interaction between the m th magnetic element and the m−1 other magnetic elements in the magnetic string provides a resultant magnetic field having a desired magnetic field strength H at the point of interest, wherein the m th magnetic element corresponds to a compensating magnetic element cm located at a position in the magnetic string corresponding to a shortest distance x cm to the point of interest and having a volume Vcm such that the desired magnetic field strength H=V cm /x cm 3 +Σ 1 m− ±V i /X i 3 .

2. The balanced magnetic array as recited in claim 1 , wherein when the desired magnetic field strength H is null, then the volume Vm of the compensating magnetic element is in accordance with V cm =Σ 1 m−1 ±V i x cm 3 /x i 3 ; where X cm <X i .

3. The balanced magnetic array as recited in claim 2 , wherein the balanced magnetic array is disposed in a flap pivotally attachable to an electronic device comprising a magnetically sensitive component.

4. The balanced magnetic array as recited in claim 3 , wherein the point of interest corresponds to a location on the flap that corresponds to the magnetically sensitive component carried by the electronic device when the flap is fully contacting the electronic device.

5. A balanced magnetic system, comprising:
an arrangement of magnetic elements that interact with each other to generate a magnetic field at a point of interest that is maintained in accordance with a magnetic interaction between the magnetic elements, the arrangement of magnetic elements comprising:
m magnetic elements, comprising:
m−1 magnetic elements, arranged in an alternating magnetic pattern wherein each of the m−1 magnetic elements comprises a magnetic volume Vm and each located a distance x i from the point of interest, and
an m th magnetic element comprising a magnetic property such that a magnetic interaction between the m th magnetic element and the m−1 other magnetic elements provides a resultant magnetic field having a desired magnetic field strength Hat the point of interest, wherein the m th magnetic element corresponds to a compensating magnetic element cm located at a position corresponding to a shortest distance x cm to the point of interest and having a volume Vcm such that the desired magnetic field strength H=V cm /x cm 3 +Σ 1 m−1 ±V i /x i 3 .

6. The balanced magnetic system as recited in claim 5 , wherein when the desired magnetic field strength is null when the magnetic interaction between the magnetic elements cancel each other out.

7. The balanced magnetic system as recited in claim 6 , wherein the desired magnetic field strength is null when the volume of the compensating magnetic element is in accordance with V cm =Σ 1 m−1 ±V i x cm 3 /x i 3 ; where x cm <x i .

8. The balanced magnetic system as recited in claim 5 , wherein the balanced magnetic system is disposed within a flap attachable to an electronic device arranged to carry a magnetically sensitive circuit.

9. The balanced magnetic system as recited in claim 8 , wherein the point of interest corresponds to a location on the flap corresponding to the magnetically sensitive circuit when the location is fully contacting the electronic device.

10. The balanced magnetic system as recited in claim 5 , wherein the m magnetic elements form a linear array of magnetic elements corresponding to a magnetic string.

11. The balanced magnetic system as recited in claim 10 , wherein magnetic elements are arranged in an alternating magnetic pattern.

Assignees

• Apple Inc

Inventors

• Corbin Sean S
• Smith Samuel Gilkison
• Kosoglow Richard D
• Stryker James A
• Zhu Hao

Classifications

• G06F1/1656

  Details related to functional adaptations of the enclosure, e.g. to provide protection against EMI, shock, water, or to host detachable peripherals like a mouse or removable expansions units like PCMCIA cards, or to provide access to internal components for maintenance or to removable storage supports like CDs or DVDs, or to mechanically mount accessories (mounting of accessories to a computer display G06F1/1607; display hoods G06F1/1603; cooling arrangements for portable computers G06F1/203) · CPC title

• G01R33/0052

  Manufacturing aspects; Manufacturing of single devices, i.e. of semiconductor magnetic sensor chips (devices based on galvano-magnetic effect or the like H10N50/85) · CPC title

• H01F7/0278 Primary

  for generating uniform fields, focusing, deflecting electrically charged particles (for magnetic separation by Lorentz force B03C1/023; specially adapted for NMR applications G01R33/383) · CPC title

• H01F7/0231 Primary

  Magnetic circuits with PM for power or force generation · CPC title

• G06F2200/1634

  Integrated protective display lid, e.g. for touch-sensitive display in handheld computer · CPC title