Dynamically stabilized magnetic array

• US 9,696,752 B2
• Filed: 03/27/2015
• Issued: 07/04/2017
• Est. Priority Date: 03/27/2015
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Stryker, James A.
• Primary Examiner(s): Nguyen, Danny
• Application Number:
  US14/671,931
• Publication Number:
  US 20160284497A1
• Time in Patent Office: 830 Days
• Field of Search: 361139, 361144, 361160
• CPC Class Codes: B23Q 3/1543 using electromagnets
• CPC Class Codes: G06F 1/16 Constructional details or arrangements
• CPC Class Codes: G06F 1/1615 with several enclosures having relative motions, each enclosure supporting at least one I/O or computing function constructional details of portable telephones comprising a plurality of mechanically joined movable body parts H04M1/0206
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/1632 External expansion units, e.g. docking stations
• CPC Class Codes: G06F 1/1643 the display being associated to a digitizer, e.g. laptops that can be used as penpads details related to the relative motion of the display enclosure with respect to the body enclosure, e.g. to move between laptop and tablet PC configuration G06F1/1615
• CPC Class Codes: G06F 1/1652 the display being flexible, e.g. mimicking a sheet of paper, or rollable
• CPC Class Codes: G06F 1/1654 the display being detachable, e.g. for remote use
• CPC Class Codes: G06F 1/1673 Arrangements for projecting a virtual keyboard
• CPC Class Codes: G06F 1/1675 Miscellaneous details related to the relative movement between the different enclosures or enclosure parts
• CPC Class Codes: G06F 1/1679 for locking or maintaining the movable parts of the enclosure in a fixed position, e.g. latching mechanism at the edge of the display in a laptop or for the screen protective cover of a PDA G06F1/1681 takes precedence
• CPC Class Codes: G06F 1/1681 Details related solely to hinges hinge details related to the transmission of signals or power are classified in G06F1/1683
• CPC Class Codes: G06F 1/1694 the I/O peripheral being a single or a set of motion sensors for pointer control or gesture input obtained by sensing movements of the portable computer
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user
• CPC Class Codes: G06F 3/017 Gesture based interaction, e.g. based on a set of recognized hand gestures interaction based on gestures traced on a digitiser G06F3/04883
• CPC Class Codes: G06F 3/046 by electromagnetic means
• CPC Class Codes: G06F 3/04886 by partitioning the display area of the touch-screen or the surface of the digitising tablet into independently controllable areas, e.g. virtual keyboards or menus
• CPC Class Codes: H01F 7/0231 Magnetic circuits with PM for power or force generation
• CPC Class Codes: H01F 7/0247 Orientating, locating, transporting arrangements
• CPC Class Codes: H01F 7/0252 PM holding devices H01F7/021, H01F7/0215, H01F7/0226 take precedence
• CPC Class Codes: H01F 7/04 : Means for releasing the attractive force
• CPC Class Codes: H01F 7/06 : Electromagnets; Actuators including electromagnets electric coils H01F5/00; devices for holding workpieces using electric force B23Q3/15; load-engaging elements for lifting articles electromagnetically B66C1/06; electromagnetic couplings F16D27/00; magnetic brakes F16D63/002; electromagnetically operated valves F16K11/24, F16K31/00; analysing materials by magnetic means G01N27/72, G01N27/80; electromagnets for winding mechanical clocks G04C1/02; electromagnetic relays H01H51/00; windings for salient poles of dynamo-electric machines H02K3/18; electromagnets for telegraphic communication H04L; for arc lamps H05B31/28
• CPC Class Codes: H01F 7/20 : without armatures cores H01F3/00; coils H01F5/00 ; shaping metal by applying magnetic forces B21D26/14; electromagnets specially adapted for NMR applications G01R33/381
• CPC Class Codes: H02N 15/00 : Holding or levitation devices using magnetic attraction or repulsion, not otherwise provided for electric or magnetic devices for holding work on machine tools B23Q3/15 ; monorail vehicle propulsion or suspension B60L13/00; sliding or levitation devices for railway systems B61B13/08; material handling devices associated with conveyors incorporating devices with electrostatic or magnetic grippers B65G47/92; separating thin or filamentary articles from piles using magnetic force B65H3/16; delivering thin or filamentary articles from magnetic holders by air blast or suction B65H29/24; bearings using magnetic or electric supporting means F16C32/04; relieving bearing loads using magnetic means F16C39/06; magnets H01F7/00; dynamo-electric clutches or brakes H02K49/00 ; electric furnaces with simultaneous levitation and heating H05B6/32
• CPC Class Codes: H03K 17/95 : using a magnetic detector
• CPC Class Codes: H03K 17/96 : Touch switches specially adapted for electronic time-pieces with no moving parts G04G21/08
• CPC Class Codes: H03K 17/97 : using a magnetic movable element
• CPC Class Codes: H03K 2217/96038 : Inductive touch switches
• CPC Class Codes: H03K 2217/96062 : with tactile or haptic feedback

Abstract

This application relates to devices and accessories that include or are configured to react with a mixture of electromagnets and permanent magnets. In particular the permanent magnets are configured to maintain persistent connections between components while the electromagnets are configured to pulse or activate periodically to maintain the connections or fix alignment of the various connections in certain circumstances.

Claims

1. An electronic device attachment system for attaching a releasable accessory device to an electronic device, comprising:

a power source;

a permanent magnet that produces a magnetic field that retains the accessory device to the electronic device;

an electromagnet switchably coupled to the power source, the electromagnet having a magnetic force strength based on an amount of energy supplied by the power source; and

a magnetic field sensor capable of detecting changes in the magnetic field, wherein when the magnetic field sensor detects a change in the magnetic field corresponding to a separation event, energy is provided from the power source to the electromagnet such that the electromagnet is activated to prevent separation of the electronic device and the accessory device.

2. The electronic device attachment system as recited in claim 1, further comprising:

a housing enclosing the power source, the electromagnet and the magnetic field sensor.

3. The electronic device attachment system as recited in claim 1, wherein the magnetic field sensor is a first magnetic field sensor, the electromagnet is a first electromagnet and wherein the electronic device further comprises:

a second electromagnet switchably coupled to the power source;

a second magnetic field sensor that electrically couples the second electromagnet with the power source; and

a comparator that determines a difference between the magnetic field changes detected by the first and second magnetic field sensors,

wherein the comparator provides a signal that directs the first and second magnetic field sensors to independently activate the first and second electromagnets.

4. The electronic device attachment system as recited in claim 1, wherein the electromagnet includes switching circuitry configured to reverse a direction current flows through coils of the electromagnet.

5. The electronic device attachment system as recited in claim 1, further comprising a user interface,

wherein a processor in communication with the user interface sends a signal directing release of the accessory device when a user input is received by the user interface requesting disconnection of the accessory device from the electronic device.

6. The electronic device attachment system as recited in claim 5, wherein the user interface comprises a touch sensitive display assembly and the power source comprises a battery.

7. The electronic device attachment system as recited in claim 1, wherein the accessory device is a protective cover that is magnetically coupled with the electronic device by way of the permanent magnet.

8. A portable electronic device, comprising:

a power source;

a number of electromagnet assemblies, each of the electromagnet assemblies comprising an electromagnet, a magnetic field sensor and a switch, the switch allowing electrical energy from the power source to energize the electromagnet when the magnetic field sensor detects a magnetic field falling within a predefined range of magnetic field characteristics; and

a permanent magnet configured to secure a magnetically attractable device to an exterior surface of the portable electronic device.

9. The portable electronic device as recited in claim 8, further comprising:

a comparator that compares magnetic field readings detected by each of the magnetic field sensors and adjusts the predefined range of magnetic field characteristics in accordance with the magnetic field readings.

10. The portable electronic device as recited in claim 9, further comprising a number of permanent magnets arranged in an alternating polarity pattern complementary to a polarity pattern formed by permanent magnets of the magnetically attractable device.

11. The portable electronic device as recited in claim 9, wherein the comparator adjusts the predefined range of magnetic field characteristics so that a first one of the electromagnets is energized before a second one of the electromagnets.

12. The portable electronic device as recited in claim 11, wherein a sequential energizing of the electromagnets is performed at an interval that causes mating surfaces of the portable electronic device and the magnetically attractable device to be aligned when the mating surface of the portable electronic device and the magnetically attractable device first come into contact.

13. The portable electronic device as recited in claim 12, wherein the magnetically attractable device is the same as the portable electronic device.

14. The portable electronic device as recited in claim 8, wherein the electromagnet comprises two sets of coils arranged about opposing ends of a substantially u-shaped magnetically attractable material, the electromagnet emitting adjacent opposite polarity fields.

15. The portable electronic device as recited in claim 8, further comprising a processor configured to direct a flow of energy through at least one of the electromagnets to be reversed.

16. A portable computing device, comprising:

a housing formed of a magnetically neutral material;

a display assembly disposed within the housing;

a battery; and

a number of electromagnet assemblies disposed within the housing, each of the electromagnet assemblies comprising an analog switching mechanism that supplies power to an electromagnet from the battery when a sensing coil detects a changing magnetic field meeting a predefined magnetic field characteristic.

17. The portable computing device as recited in claim 16, wherein the analog switching mechanism comprises a field effect transistor switch.

18. The portable computing device as recited in claim 17, wherein the field effect transistor switch comprises a band pass filter that determines whether the predefined magnetic field characteristic is met and limits a duty cycle of the electromagnet.