Patent ID: 7965439

Claim:
A scanning device comprising: an optical element in which a refractive index distribution changes according to the intensity of an electric field generated therein such that an incident laser beam is scanned to one side; first and second electrodes provided on two opposite surfaces of the optical element; and a control unit that controls a voltage applied to at least one of the first and second electrodes such that the electric field is generated in one direction while the laser beam is scanned to one side and then, after the laser beam is scanned to the one side, the electric field is generated in the optical element in the other direction opposite to the one direction with time by supplying a refresh voltage to at least one of the first and second electrodes, the voltage being applied such that the voltage gradually increases for a first period of time, the refresh voltage being applied for a second period of time, and the second period of time being shorter than the first period of time.