CLEANING DEVICE, IMAGING UNIT INCLUDING CLEANING DEVICE, AND CLEANING METHOD

A cleaning device includes a housing holding an imaging device, a protective cover located in a field of view of the imaging device, a vibrator to vibrate the protective cover, a piezoelectric driver to drive the vibrator, a cleaning liquid discharger to discharge, onto a surface of the protective cover, a cleaning liquid including an abrasive, and a signal processing circuit to control the piezoelectric driver and the cleaning liquid discharger. When causing the cleaning liquid discharger to discharge the cleaning liquid, the signal processing circuit can control the piezoelectric driver such that the protective cover is vibrated at a vibration acceleration of larger than about 8.0×10m/sand equal to or less than about 21.0×10m/s.