VIBRATOR, OPTICAL SCANNER, VIDEO PROJECTION DEVICE, AND IMAGE FORMING DEVICE

PROBLEM TO BE SOLVED: To provide a vibrator configured to significantly improve design flexibility, while ensuring desired vibration characteristics, and to provide an optical scanner, a video projection device, and an image forming device.SOLUTION: A vibrator comprises: a vibration part (beam part 31) with an optical mirror part 322; and a drive part (magnetic field applying means 70 or the like) for vibrating the vibration part. The vibration part has vibration characteristics where the shape of a peak in a resonance characteristic curve showing a relation between the amount of change in resonance frequency and strain amplitude is line symmetry. The vibrator 30 significantly improves design flexibility while ensuring desired vibration characteristics. Components for driving are reduced as well as the vibrator 30, to improve performance of an actuator device 1, an optical scanner, a video projection device, and an image forming device.