| 摘要 |
<P>PROBLEM TO BE SOLVED: To drive a linear vibration motor at a frequency as close as possible to a natural frequency of the linear vibration motor, irrespective of the state of the linear vibration motor. <P>SOLUTION: A drive-signal generating part 10 generates a drive signal for allowing a positive current and a negative current used to alternately deliver a positive current and a negative current to a coil L1 with a nonconducting period inserted between conducting periods. A driver unit 20 generates a drive current in response to the drive signal generated by the drive signal generating unit 10, and supplies the drive current to a coil L1. An induced voltage detector 30 detects an induced voltage occurring in the coil L1 during the nonconducting period. A zero-cross detecting unit 40 detects the zero cross of the induced voltage detected by the induced voltage detector 30. The drive signal generator 10 estimates the eigen frequency of the linear vibration motor 200 based on a detected position of the zero cross, and the frequency of the drive signal is brought close to the estimated eigen frequency. <P>COPYRIGHT: (C)2011,JPO&INPIT |
