A metal baseball or softball bat may be improved both for durability and performance by selectively placing a layer of polymer material around portions of the bat. The movable connecting member can be formed by combining a plurality of rod bodies. The left gate driver is connected to supply selection signals to TFTs of pixels of a left half of a pixel portion. In this method, a light beam from the light source is divided into multiple light beams and the multiple light beams are combined on the document. The buck converter circuit may be configured to be selectively enabled and disabled in response to a control signal, and the switched capacitor voltage converter circuit may be configured to operate when the buck converter circuit is disabled.