Abstract: A weld portion detector (20) and a laser beam projector (10) disposed a predetermined distance behind the weld portion detector (20) are moved together. The weld portion detector (20) detects a weld line and the laser beam projector (10) projects on the weld line detected by the weld portion detector (20) for laser welding. Pieces of data on weld positions sequentially detected by the weld portion detector (20) are stored sequentially in combination with times when the pieces of data on the weld positions are obtained and moving speeds of the weld portion detector (20) in a memory. A time when the weld portion detector (20) passed a point at which the laser beam projector (10) has just arrived is calculated on the basis of the times and the moving speeds stored in the memory. The laser beam projector (10) projects a laser beam on a weld position detected at the thus calculated time.

Abstract: A laser-welding head is capable of applying a fixed pressure to parts to be welded of workpieces regardless of the undulation of the surfaces of the parts to be welded. The laser-welding head includes a pressing device (12) having a roller (16) which rolls along parts of workpieces near a weld line (40) to press together the same parts of the workpieces, a pressing unit (6) for applying a predetermined pressure to the pressing device (12) to press the pressing device (12) toward the parts of the workpieces near the weld line (40), and a laser beam projecting unit (17) mounted on the pressing unit (6) for movement together with the pressing device (12). The pressing unit (6) is provided with a pneumatic cylinder actuator for applying the predetermined pressure to the pressing device (12).

Abstract: A weld portion detector (20) and a laser beam projector (10) disposed a predetermined distance behind the weld portion detector (20) are moved together. The weld portion detector (20) detects a weld line and the laser beam projector (10) projects on the weld line detected by the weld portion detector (20) for laser welding. Pieces of data on weld positions sequentially detected by the weld portion detector (20) are stored sequentially in combination with times when the pieces of data on the weld positions are obtained and moving speeds of the weld portion detector (20) in a memory. A time when the weld portion detector (20) passed a point at which the laser beam projector (10) has just arrived is calculated on the basis of the times and the moving speeds stored in the memory. The laser beam projector (10) projects a laser beam on a weld position detected at the thus calculated time.

Abstract: A laser beam projector to be employed in an automatic welding machine, such as a robot, includes an optical head of projecting a laser beam and a holding and turning mechanism of holding and turning the optical head. The spot of the laser beam can be accurately located on the portion to be welded by turning the optical head by the holding and turning mechanism.

Abstract: A laser-welding head is capable of applying a fixed pressure to parts to be welded of workpieces regardless of the undulation of the surfaces of the parts to be welded. The laser-welding head includes a pressing device (12) having a roller (16) which rolls along parts of workpieces near a weld line (40) to press together the same parts of the workpieces, a pressing unit (6) for applying a predetermined pressure to the pressing device (12) to press the pressing device (12) toward the parts of the workpieces near the weld line (40), and a laser beam projecting unit (17) mounted on the pressing unit (6) for movement together with the pressing device (12). The pressing unit (6) is provided with a pneumatic cylinder actuator for applying the predetermined pressure to the pressing device (12).

Abstract: A method of fabricating a semiconductor integrated circuit comprises the steps of: forming buried layers in predetermined regions of a semiconductor substrate; forming an epitaxial layer covering the substrate and the buried layers; forming isolation regions dividing the epitaxial layer into a plurality of islands; selectively implanting ions to form a base region of a vertical bipolar transistor in a surface layer of one island and simultaneously to form a resistor region in a surface layer of another island; and selectively diffusing impurities into a surface layer of the base region, to form an emitter region of the vertical bipolar transistor.