Abstract: A dust collector for a laser drilling machine is provided between a lens table and a workpiece to be processed and includes an upper inlet port and a lower inlet port arranged on one side of a space defined by four side walls, and an exhaust port arranged opposite the inlet ports. The total amount of air supplied from the two inlet ports is 30 to 70% of the exhaust rate. The lower inlet port has an air supply capacity 1.5 to 4.5 times that of the upper inlet port.

Abstract: A dust collector for a laser drilling machine is provided between a lens table and a workpiece to be processed and includes an upper inlet port and a lower inlet port arranged on one side of a space defined by four side walls, and an exhaust port arranged opposite the inlet ports. The total amount of air supplied from the two inlet ports is 30 to 70% of the exhaust rate. The lower inlet port has an air supply capacity 1.5 to 4.5 times that of the upper inlet port.

Abstract: A color selecting electrode for a color-picture tube, includes a rectangular frame-shaped frame having a pair of mutually-opposite long sides and a pair of mutually-opposite short sides, and a mask plate which is stretchedly supported on top surfaces of the frame while receiving a resilient spring force exerted from the frame, the long sides having a greater section modulus and a greater rigidity than the short sides. A method of manufacturing the color selecting electrode includes the step of welding, to the frame pressed inward by an equally-distributed force applied to the pair of long sides and the pair of short sides, the mask plate of which four sides are stretched outward by a distributed force which approximately counterbalances the equally distributed force.