Patent ID: 8736201
Filing Date: 2014-05-27
Classification: H02P

Abstract:
1. A drive control circuit of a linear vibration motor, having a stator and a vibrator at least one of which is constituted by an electromagnet, which vibrates the vibrator relative to the stator by supplying a drive current to a coil of the electromagnet, the drive control circuit comprising: a drive signal generating unit configured to generate a drive signal used to alternately deliver a positive current and a negative current to the coil; a driver unit configured to generate the drive current in response to the drive signal generated by said drive signal generating unit so as to supply the drive current to the coil; and an induced voltage detector configured to detect an induced voltage occurring in the coil, wherein after a running of the linear vibration motor has terminated, said drive signal generating unit generates a drive signal whose phase is opposite to that of the drive signal generated during the vibration motor running, said drive signal of the opposite phase including a high impedance period during which said driver unit is controlled to a high impedance state, wherein said induced voltage detector detects the induced voltage occurring in the coil during the high impedance period, and wherein said drive signal generating unit estimates, from the induced voltage, a vibration force after the running of the linear vibration motor has terminated, and controls said drive signal of the opposite phase based on the estimated vibration force.