Patent ID: 8576291

Claim:
A drive unit, comprising: a shape memory alloy configured to move, by being supplied with electric current, a driven member in a first direction and in a second direction opposite to the first direction; a drive section configured to supply electric current to the shape memory alloy; a shape memory alloy resistance calculation section configured to calculate a resistance of the shape memory alloy when the shape memory alloy is supplied with electric current by the drive section, the resistance being used to measure a position of the driven member; a control section configured to control the supply of the electric current to the shape memory alloy; a comparison section configured to compare the resistance from the shape memory alloy resistance calculation section with a target resistance corresponding to a target position from the control section; a drive amount calculation section configured to calculate a drive amount of the shape memory alloy on the basis of a comparison result of the comparison section and to output the drive amount to the drive section; and a storing section configured to previously store hysteresis correction values based on resistance to be used to correct hysteresis between a case of moving the driven member in the first direction and a case of moving the driven member in the second direction, wherein the hysteresis correction value is a difference between a resistance of the shape memory alloy corresponding to a target position in a case of moving the driven member in the second direction and a resistance of the shape memory alloy corresponding to the target position in a case of moving the driven member in the first direction, wherein when the driven member, which has been moved in the first direction or the second direction and has reached a position beyond the target position, is to be moved in a reverse direction to the target position, the drive amount calculation section outputs the drive amount on the basis of a comparison result from the comparison section in which a comparison has been made by using the hysteresis values.