A blind-rivet gun includes a gun header, a cylinder, a piston, and an air saving device. Models are used to guide the placement and routing of polygons on the IC layout based upon predictions of manufacturing variations. These languages can be extended to support a marker-semantic to more easily solve several problems that are otherwise not easily solved. The focus actuator is fixed to the second lens unit and electrically drives the focus lens unit relative to the second lens unit in the optical axis direction. The charge pump is responsible for turning on a pair of transistors which bring the power bus voltage down to a zero level. The plurality of first buffers are supplied with the first ground voltage, the plurality of second buffers are supplied with the first power voltage, and a signal output from a previous portion of the semiconductor device is input into the first and second buffers at predetermined time intervals.