Patent ID: 8143983
Filing Date: 2012-03-27
Classification: G06F,G06T,H01F,Y10T

Abstract:
1. An electronic device having a housing, comprising: a dual state magnetic element comprising a first plurality of magnetic components and a second plurality of magnetic components, the dual state magnetic element disposed within the housing at a first side wall and arranged to provide a first magnetic surface at an exterior surface of the first side wall in an inactive state, the first magnetic surface not substantially affecting a magnetically sensitive device at the exterior surface, wherein in an active state, the dual state magnetic element provides a second magnetic surface at the exterior surface of the first side wall, the second magnetic surface suitable for generating a peak magnetic attachment force for forming a magnetic attachment between the electronic device and a magnetic assembly in a first part of an accessory unit, wherein the magnetic assembly is arranged to magnetically attach the accessory unit to a first part of the electronic device with the peak magnetic force, the magnetic assembly comprising: a housing having a front opening, a first end lug pivotally connected to an end of the housing, a second end lug pivotally connected to an opposite end of the housing, wherein the first and second end lugs and the housing pivot about a first pivot line, a rigid connecting rod connecting the first and second end lugs, a collar sized to accommodate the rigid connecting rod, the collar and rigid connecting rod inserted into an opening in the accessory body, the rigid connecting rod forming a second pivot line different than the first pivot line about which the first and second end lugs pivot; and a state maintaining means coupled to the housing and arranged to maintain the dual state magnetic element in the inactive state by providing a retaining force, wherein an off peak magnetic attachment force has a force value that is equal to or greater than one half of a force value of the peak magnetic attachment force, wherein the dual state magnetic element changes from the inactive state to the active state only when the magnetic assembly in the first part of the accessory device aligns with corresponding ones of the first plurality of magnetic components and the second plurality of magnetic components, and wherein when the dual state magnetic element changes from the inactive to the active state, the dual state magnetic element moves from a first position to a second position against the retaining force a distance Δx towards the first sidewall wherein the state maintaining means comprises a spring having a spring constant k, and wherein the retaining force is directly related to the distance Δx and the spring constant k.