Patent ID: 7608979

Claim:
A driving device, comprising: an electromechanical conversion element which expands and contracts in response to an application of voltage; a predetermined member which reciprocates with the movement of expanding and contracting of the electromechanical conversion element; a moving member which engages with the predetermined member with frictional force and moves relatively to the predetermined member by the movement of expanding and contracting of the electromechanical conversion element; and a voltage applying section which applies a voltage to the electromechanical conversion element repeating a first output cycle, with a fixed time cycle, constituted of an integral number of second output cycles each of which includes a first voltage having a first period and a second voltage, having a second period, lower than the first voltage, and a third voltage lower than the second voltage, wherein the voltage applying section comprises a velocity change section which changes a moving velocity of the moving member by replacing at least one of the second output cycles with a voltage signal of the second voltage having the same period as the second output cycle to be replaced.