Patent ID: 6889408

Claim:
A buckle apparatus comprising: an apparatus main body into which a tongue plate is insertable, the tongue plate being assembled to a webbing belt that restrains a body of a vehicle occupant by being draw from a predetermined region in the vehicle and fitted over the body of the vehicle occupant; a latch which is moveable toward and away from the tongue plate inserted into the apparatus main body, the latch engaging with the tongue plate by moving toward the tongue plate, for limiting movement of the tongue plate in a disengaging direction, which is opposite to an insertion direction of the tongue plate; a giant magnetoresistive element provided at the apparatus main body, the giant magnetoresistive element being structured to include an element main body formed by alternately laminating ferromagnetic substance layers, which are formed by a ferromagnetic substance in this film form, and non-magnetic substance layers, which are formed by a non-magnetic substance in this film form; a permanent magnet which forms a predetermined magnetic field therearound and is provided at the apparatus main body, the permanent magnet forming the predetermined magnetic field therearound and being disposed in the apparatus main body so as to face the giant magnetoresistive element, the magnet having two opposing magnetic poles that are aligned along an axis that is substantially parallel with a direction that said tongue plate is inserted into said main body, and substantially orthogonal to said layers of said magnetoresistive element, each of said poles of said magnet simultaneously and continuously facing said giant magnetoresistive element, and a shielding member, which interlocks with the tongue plate inserted at the apparatus main body, the shielding member being provided so as to be movable in conjunction with movement of the tongue plate, such that when the tongue plate moves to a position at which the latch and the tongue plate engage, the shielding member is interposed between the giant magnetoresistive element and the permanent magnet, and shields lines of magnetic force from the permanent magnet toward the giant magnetoresistive element.