Patent ID: 7791869

Claim:
An electronic device comprising: a device main body unit; a rotation unit freely rotatably supported to the device main body unit; a display unit provided to the rotation unit, the rotation unit rotating between a closure posture in which the display unit faces the device main body unit and a display posture in which the display unit is away from the device main body; a magnet provided to one of the device main body unit and the rotation unit; and a detector provided to the other of the device main body unit and the rotation unit, wherein: diverse magnetic poles of the magnet are arranged in mutually opposite directions in a surface orthogonal to a rotation central line of the rotation unit; the detector has a fixed magnetic layer in which a direction of magnetization is fixed and a free magnetic layer in which the magnetization is changed due to external magnetic field and is composed of a magnetoresistance effect element capable of detecting the direction and intensity of the external magnetic field on the basis of the direction of the magnetization of the fixed magnetic layer and the direction of the magnetization of the free magnetic layer; and the detector detects an intensity change of the magnetization in one direction output from the magnet and obtains a first open detection output when the rotation unit is rotated at a predetermined angle from the closure posture to the display posture, and the detector detects an intensity change of the magnetization in the other direction output from the magnet and obtains a second open detection output when the rotation unit is further rotated toward the display posture after the first open detection output is obtained.