Optical scanning device and driving method of optical scanning device

A driving method of an optical scanning device including

• a mirror portion that has a reflecting surface which reflects incident light,
• a first actuator that swings the mirror portion around a first axis,
• a second actuator that swings the mirror portion around a second axis intersecting the first axis,
• a first angle sensor that outputs a signal corresponding to an angle of the mirror portion around the first axis, and
• a processor that applies a first driving signal having a first driving frequency to the first actuator and applies a second driving signal having a second driving frequency to the second actuator,
• the driving method comprising:
• causing the processor to derive a first phase difference between the first driving signal and an output signal of the first angle sensor based on the output signal of the first angle sensor, and
• perform processing of changing the first driving frequency and the second driving frequency while maintaining a ratio of the first driving frequency and the second driving frequency along a frequency ratio line set in advance such that the first phase difference is within a first target range, and
• wherein the frequency ratio line is a line representing a frequency ratio corrected based on a change amount of a ratio of a first resonance frequency in a case where the mirror portion swings around the first axis and a second resonance frequency in a case where the mirror portion swings around the second axis.