Abstract: A display apparatus capable of performing authentication in a short time is provided. The display apparatus includes a first display portion where first pixels are arranged in a matrix, a second display portion where second pixels are arranged in a matrix, first and second row driver circuits, and a control circuit. Each of the first and the second pixels includes a light-receiving element. The first and the second pixels each have a function of acquiring imaging data by using the light-receiving element. The first and the second row driver circuits each have a function of selecting the first and the second pixels which read out the imaging data. The control circuit has a function of sequentially driving the first and the second row driver circuits in a first mode, and has a function of driving one of the first and the second row driver circuits on the basis of the imaging data in the second mode.

Abstract: A silicon semiconductor material is charged in a double-structured crucible of an outer crucible and an inner crucible. The crucible is heated from the upper side thereof by the heat radiated from a heating member energized by an induction heating coil, so that the silicon raw semiconductor material is melted. The bottom of the crucible is mounted on a supporting bed cooled by cooling water supplied from a cooling medium tank. The silicon semiconductor material is melted in the inner crucible and starts solidifying from the bottom portion thereof. The silicon semiconductor material expands in volume at the time of solidification. Since a gap is formed between the inner crucible and the outer crucible, however, the outward extension of the inner crucible with the silicon semiconductor material alleviates a strain generated at the time of solidification, thereby producing an excellent polycrystalline semiconductor ingot.

Abstract: A method for manufacturing a seamless pipe, comprises:preparing a billet made of an alloy steel or an alloy;joining a steel plate to an end surface at which piercing of the billet is commenced;preparing a piercing plug made of Mo, a Mo alloy or a heat-resisting steel;hot-piercing the billet by using the piercing plug to produce a hollow shell; androlling the hollow shell to produce a seamless pipe.