Patent ID: 7187154

Claim:
A motor drive apparatus comprising: a first angular velocity calculating means for calculating an angular velocity ω 1 of a brushless motor using a back-EMF of said brushless motor; a second angular velocity calculating means for calculating an angular velocity ω 2 of said brushless motor using signals of plural Hall sensors disposed in said brushless motor; and a selecting means which when a rotation speed of said brushless motor is lower than a predetermined rotation speed, selects an angular velocity ω 1 calculated by said first angular velocity calculating means and when the rotation speed of said brushless motor is higher than said predetermined rotation speed, selects an angular velocity ω 2 calculated by said second angular velocity calculating means, wherein said second angular velocity calculating means calculates said angular velocity ω 2 using a signal of said Hall sensor at a time of calculation and a signal of plural Hall sensors before the calculation time.