Abstract: A projector is provided which includes: a Peltier device having a first surface in contact with an optical component (heat generating component) and a second surface in contact with a heat sink (heat dissipating component); and a Peltier device driving unit as a controller that generates a temperature difference between the two surfaces of the Peltier device by applying a cyclically changing voltage to the Peltier device. The Peltier device driving unit applies to the Peltier device a first voltage in a first of two time periods of a cycle and applies a lower second voltage in the second time period, the first voltage being for transferring heat from the optical component to the heat sink to reduce the temperature of the first surface below that of the second surface, and the second voltage being for preventing the transfer of heat from the second surface to the first surface.

Abstract: An object of the present invention is to provide a self-propelled apparatus that can conduct efficient performance by avoiding an obstacle in a more suitable manner. Concerning the self-propelled apparatus, rotation direction determination section determines rotation direction randomly, when obstacle that exists in a direction that is substantially the same with traveling direction of the self-propelled apparatus is detected, determines rotation direction to a clockwise direction, when obstacle that exists in left side with respect to traveling direction line that runs through center point of the self-propelled apparatus is detected, and determines rotation direction to an anti-clockwise direction, when obstacle that exists in right side with respect to traveling direction line that runs through center point of the self-propelled apparatus is detected. Rotation angle of the self-propelled apparatus is determined by the rotation angle determination section.