Abstract: A color selection apparatus for a cathode ray tube. A mask is formed having a long axis and a short axis. A frame supports the mask in one of a long axis direction and a short axis direction. The mask has a plurality of strips separated by a predetermined distance. A plurality of first beam apertures are formed as single long slits between the strips in a center portion of the mask. A plurality of second beam apertures are formed on outer portions of the mask to both sides of the center portion of the mask. The second beam apertures are divided into a plurality of individual units within a single column by real bridges and at least one dummy bridge for each individual second beam aperture unit. The at least on dummy bridge extends inwardly from the strips but does not cross completely through the individual second beam aperture unit.

Abstract: A tension mask cathode ray tube has a vacuum tube and an inner shield mounted within the vacuum tube to shield the vacuum tube from geomagnetism. A value Br/Hc of the inner shield where Br indicates a residual magnetic flux density and Hc indicates a coercive force is established to be 1.0-2.0 times more than a value Br/Hc of the mask frame. In this structure, the route of electron beams is established to be more precise. Consequently, the purity characteristic and the convergence characteristic are improved while forming a precise raster. In this way, the display screen quality can be enhanced.

Abstract: A color selection apparatus for a cathode ray tube includes a mask bearing a shape with short and long axes, and a frame combined with the mask. The mask is fitted to the frame while being tensioned either in the long axis direction or in the short axis direction. The mask has a plurality of strips spaced apart from each other by a predetermined distance, a plurality of real bridges disposed between the neighboring strips with a predetermined pitch while defining beam-guide holes, and one or more dummy bridges placed within each beam-guide hole while being extended from the strips in at least one direction. In any one reference column of m=0 and the other neighboring columns of m±n (n is a natural number), the real bridges arranged at the reference column are placed at lines different from the real bridges arranged at the columns of at least m±2 in the long axis direction.

Abstract: The present invention describes the details of a flat mask before tension is applied, an assembling method of that flat mask, and a tension mask assembly manufactured by using that method in order to obtain satisfactory thermal expansion, uniform stress distribution and linearity. The flat mask includes an apertured portion and supporting ends surrounding the apertured portion. The apertured portion comprises a plurality of concave pin-cushion type or convex barrel type strips, a plurality of real bridges connecting strips and dividing slots, and dummy bridges formed in the slots. The short supporting ends have the same width along a longitudinal direction and are formed to have the same curvature as the strips facing the supporting ends. The short supporting ends are preferably half-etched in order to make the volume of material removed from the short supporting ends greater than the volume of material removed from the apertured portion.

Abstract: A tension mask cathode ray tube has a vacuum tube and an inner shield mounted within the vacuum tube to shield the vacuum tube from geomagnetism. A value Br/Hc of the inner shield where Br indicates a residual magnetic flux density and Hc indicates a coercive force is established to be 1.0-2.0 times more than a value Br/Hc of the mask frame. In this structure, the route of electron beams is established to be more precise. Consequently, the purity characteristic and the convergence characteristic are improved while forming a precise raster. In this way, the display screen quality can be enhanced.

Abstract: The present invention describes the details of a flat mask before tension is applied, an assembling method of that flat mask, and a tension mask assembly manufactured by using that method in order to obtain satisfactory thermal expansion, uniform stress distribution and linearity. The flat mask includes an apertured portion and supporting ends surrounding the apertured portion. The apertured portion comprises a plurality of concave pin-cushion type or convex barrel type strips, a plurality of real bridges connecting strips and dividing slots, and dummy bridges formed in the slots. The short supporting ends have the same width along a longitudinal direction and are formed to have the same curvature as the strips facing the supporting ends. The short supporting ends are preferably half-etched in order to make the volume of material removed from the short supporting ends greater than the volume of material removed from the apertured portion.

Abstract: A color selection apparatus for a cathode ray tube. A mask is formed having a long axis and a short axis. A frame supports the mask in one of a long axis direction and a short axis direction. The mask has a plurality of strips separated by a predetermined distance. A plurality of first beam apertures are formed as single long slits between the strips in a center portion of the mask. A plurality of second beam apertures are formed on outer portions of the mask to both sides of the center portion of the mask. The second beam apertures are divided into a plurality of individual units within a single column by real bridges and at least one dummy bridge for each individual second beam aperture unit. The at least on dummy bridge extends inwardly from the strips but does not cross completely through the individual second beam aperture unit.

Abstract: A color selection apparatus for a cathode ray tube includes a mask bearing a shape with short and long axes, and a frame combined with the mask. The mask is fitted to the frame while being tensioned either in the long axis direction or in the short axis direction. The mask has a plurality of strips spaced apart from each other by a predetermined distance, a plurality of real bridges disposed between the neighboring strips with a predetermined pitch while defining beam-guide holes, and one or more dummy bridges placed within each beam-guide hole while being extended from the strips in at least one direction. In any one reference column of m=0 and the other neighboring columns of m±n (n is a natural number), the real bridges arranged at the reference column are placed at lines different from the real bridges arranged at the columns of at least m±2 in the long axis direction.

Abstract: A method for producing a high strength hot-rolled steel sheet with good formability applicable to automobiles, industrial machines and the like is disclosed. The basic composition of TRIP steel is adjusted wherein Cu is added to improve the strength by precipitation hardening of a fine &egr;—Cu. Other conditions are controlled to obtain a tensile strength of over 90 kg/mm2 with good formability. The steel is composed of 0.15-0.3% by weight of C, 1.5-2.5% by weight of Si, 0.6-1.8% by weight of Mn, 0.02-0.10% by weight of Al, 0.6-2.0% by weight of Cu, 0.6-2.0% by weight of Ni, the balance being Fe and inevitable impurities and has a microstructure of multi-phase structure consisting of ferrite, bainite, and retained austenite, or a granular structure (M-A constituents in bainitic ferrite matrix). The steel is finish rolled at a temperature of 750-880° C., water cooled from a water cooling initiation temperature of 680-740° C.