Abstract: In order, to manufacture a high-performance infrared-emitting element having high-speed thermal response characteristics and a high infrared emissivity, a bridge (heat-generating) portion having a separation space is formed on a silicon element substrate. The bridge portion is formed to have a thickness of 5 &mgr;m or less by doping boron as an impurity by ion implantation with a concentration distribution peak value of 1.5×1019 atoms/cm3 or more, and performing annealing under predetermined conditions for activating the impurity layer. In the infrared-emitting element manufactured in this manner, even if the bridge portion is made thin to improve the thermal response characteristics, the infrared emissivity does not decrease because of a high impurity concentration, and a large temperature modulation width can be obtained. In doping boron as the impurity by ion implantation, the dose is preferably set to 3.0×1014 ions/cm2 or more.

Abstract: A roll rearranging apparatus is so constructed that an upper roll unit of a tension leveler can be taken in and out together with a lower roll group from a housing. In order to greatly reduce the rearranging time and improve the production efficiency by reduction of labor and the safety of work, the apparatus comprises an arm which is provided at a work side end of a roll support supporting a roll unit, the arm including a hole at a lower side thereof, and an engagement capable of being engaged with the hole of the arm and including a moving up and down mechanism.

Abstract: A welding apparatus for butt weld joint of steel plates such as steel strips is assembled together with a grinding device, which is combined in one system. The grinding device is so arranged that grinding wheels of this system can be moved along the welded joint following just after the welding torch. The clamping dies for clamping the welding portion of the steel plates are divided sectionally provided with mechanisms for shifting the respective divided clamping dies between a first clamping position during welding and a second clamping position during grinding. The upper unit of the grinding device can be moved along a rail assembly for guiding the welding torch. The lower unit of the grinding device can be moved along a rail assembly for guiding the shearing machine.