An Assist Control Unit 61 detects a power generation state of an electric motor where the direction for generating torque of motor current im does not match the rotational direction of steering speed \u03c9x, and calculates an Amount E Corresponding to Power Generation Energy during a period when the power generation state is detected continuously. The quartz schist radiates far-infrared rays at an ordinary temperature. A display section displays the subject image based on image data associated with the subject image obtained by the imaging section. The prefetch block address is respectively determined in one dimension or multiple dimensions.