Disclosed herein is a motor driving apparatus including: an actuator for converting electric energy into rotary motion; a monitoring unit for monitoring a state of the actuator; a control unit for generating a control signal based on an output voltage of the monitoring unit; and a driving signal generation unit for generating a driving signal for the actuator based on the control signal. The elongated tube portion is constructed from a flexible, resilient material that may be repeatedly and forcibly deformed. The optical head extends parallel to the longitudinal axis. The rail members are adapted to engage opposite edges of the substrate.