Abstract: A tension mask assembly for a flat cathode ray tube includes a tension mask having a plurality of strips separated from one another by a predetermined gap, real bridges connecting adjacent strips to thus define slots through which electron beams pass, and first and second dummy bridges extending from adjacent strips toward each slot therebetween, the tension mask being installed such that its top surface faces a panel forming a screen and it is separated from the panel by a predetermined gap, a plurality of supporting members disposed at opposite sides of the tension mask to support the tension mask, and a plurality of rigid members secured to opposite ends of the supporting members to apply tension to the tension mask. A first etching boundary formed at an end of the first dummy bridge near to the center of the tension mask is lower with respect to the screen than a second etching boundary formed at an end of the second dummy bridge near to the periphery of the tension mask.

Abstract: A cathode ray tube with a panel that has a thickness of the central portion of an effective area of a screen surface that is TC, a thickness of a vertical edge that is TV, a thickness of a horizontal edge portion that is TH, and a thickness of an edge in a diagonal direction that is TD. The respective values of TC, TV, TH and TD satisfy the expression (TH−TC)+(TV−TC)+(TD−TC)<TC/3, and the radius of curvature in the diagonal direction of the outer surface of the effective area is 1450 mm or more. Thus, by limiting the difference in thickness of the central portion and the peripheral portion of the effective screen area of the panel and the curvature radius of the inner and outer surfaces of the effective screen, the weight of the panel is reduced and an increase of an incident angle caused by flatness of the screen panel is prevented so that a convergence feature of an electron beam is improved.

Abstract: A shadow mask frame assembly of a flat cathode ray tube (CRT) includes a shadow mask including a plurality of strips formed at a main body in a vertical direction by being separated a predetermined distance by slits and a plurality of bridges forming slots by connecting neighboring strips and sectioning the slits, in which the slots include a first slot group including slots having a wide interval between the bridges and a second slot group including slots having a narrow interval between the bridges, first and second support members secured at a long side portion of the shadow mask, and a frame including first and second elastic members, either end portion of each of which is secured to each of the first and second support members, for applying a tension force to the shadow mask.