Patent ID: 8125174

Claim:
A motor driven electronic apparatus comprising: a stepping motor including a two pole flat stator, a rotor including a two pole permanent magnet coupling magnetically with the two pole flat stator through a gap, stopping with detent torque and secured to the rotor shaft, and a drive coil; an amplifier constituting a rotor position detector and amplifying a counter electromotive voltage generated on the drive coil by motion of the rotor on the basis of a reference voltage for amplifier; a comparator constituting the rotor position detector, detecting a rotor position from an output of the amplifier and having hysteresis including an upper threshold voltage and a lower threshold voltage on the basis of a reference voltage for comparator outputted by a reference voltage circuit for comparator; a drive pulse generation circuit generating a drive pulse at timing of the rotor position; and a driver supplying a bipolar drive current corresponding to the drive pulse onto the drive coil and driving the stepping motor, wherein at least any one of the reference voltages used for the amplifier or the reference voltages used for the comparator are more than one.