A motor driver device includes: a driver driving a motor by a driving method, wherein the driving method includes: a first driving method performing driving control of the motor based on zero cross timing of back electromotive force generated in a coil of a predetermined phase; and a second driving method performing driving control of the motor such that a first differential phase between zero cross timing of driving current flowing through the coil of the predetermined phase and zero cross timing of driving voltage applied to the coil of the predetermined phase coincides with predetermined first target phase, and wherein, even when the motor is being driven by the first driving method, the first differential phase is sequentially detected and, when transition from the first driving method to the second driving method occurs, the first differential phase detected immediately before the transition is set to the first target phase.