Abstract: A cathode ray tube includes a tube having a panel having an inner phosphor screen, a funnel connected to the panel, a neck connected to the funnel, a deflection unit disposed around the funnel, an electron gun installed in the neck, and a scatter-proof unit installed on the panel and the funnel such that the panel shares the scatter-proof unit with the funnel for preventing the tube from breaking and scattering into many pieces.

Abstract: A color selection apparatus for a cathode ray tube. A mask frame having a pair of supporting members is disposed in parallel and spaced away from each other. A pair of elastic members is disposed between and coupled to the supporting members. A tensioned mask is coupled to the supporting members and is provided with a plurality of beam-passing apertures. A spring assembly includes a hook having a frame fixing part fixed on the mask frame and a spring fixing part and a spring fixed to the spring fixing part. The hook has a cut-away portion defined by cutting a portion of the frame fixing part. The cut-away portion forms a welding portion for welding the hook to the mask frame.

Abstract: A tension mask frame assembly for a color cathode ray tube, includes: a tension mask having a plurality of strips on which slots are formed, the slots being separated by a predetermined distance from each other on a thin plate; real bridges for partitioning slots at a predetermined pitch interval by connecting adjacent ones of a plurality of strips to each other; and a frame which supports the corresponding edges of the tension mask; whereby the vertical pitch of the real bridges becomes smaller, such as in a stepwise relation, in a direction from the center portion of the tension mask to the peripheral portion of the tension mask.

Abstract: A color selection apparatus includes a frame comprising a pair of supporting members disposed in parallel with each other and a pair of elastic members disposed between and coupled to the supporting members. Each of the elastic members is formed of a hollow tube. A mask is coupled to the supporting members while being applied with a predetermined tension, and exhaust openings are formed for exhausting remaining alien substances from within the elastic members during an assembling process of the color selection apparatus. The exhaust openings are formed on each of the elastic members at a portion adjacent to where the elastic members are coupled to the supporting members.

Abstract: A flat tension mask frame assembly is provided, including a frame and a tension mask. The frame has first and second support members which are separated from each other by a predetermined distance, and have fixing portions and flange portions which are bent inwardly from the fixing portions and become narrower from the center portion to both ends of the flange portions, and at least two elastic members fixed at both ends to the first and second support members for supporting the support members. The tension mask has facing edges which are fixed to the fixing portions of each of the first and second support members in a state where a tensile stress has been applied to the facing edges.

Abstract: A tension mask frame assembly for a color cathode ray tube, including: a tension mask having a plurality of strips on which slots are formed being separated a predetermined distance from each other on a thin plate, real bridges for partitioning slots at a predetermined pitch interval by connecting adjacent ones of a plurality of strips to each other; and a frame which supports the corresponding edges of the tension mask, whereby a tensile force is applied to the tension mask, and the vertical pitch of the real bridges becomes smaller in a direction from the center portion of the tension mask to the peripheral portion of the tension mask.

Abstract: A tension mask frame assembly for a color cathode-ray tube, including a tension mask, a frame and a vibration prevention unit, is provided. In this tension mask frame assembly, the tension mask has a slotted portion in which a plurality of electron beam passing holes are formed and a non-slotted portion located on the edge of the slotted portion. The frame supports two facing sides of the tension mask to apply a tensile force to the tension mask. The vibration prevention unit includes a damper having first and second attenuation portions that are maintained at a predetermined angle to form an insertion portion into which the edges of the tension mask not supported by the frame are inserted, and a support member for suspending the damper from the edges of the tension mask by passing through the first and second attenuation portions and the edges of the tension mask inserted into the insertion portion formed by the first and second attenuation portions.

Abstract: A color selection apparatus for a cathode ray tube. A mask frame having a pair of supporting members is disposed in parallel and spaced away from each other. A pair of elastic members is disposed between and coupled to the supporting members. A tensioned mask is coupled to the supporting members and is provided with a plurality of beam-passing apertures. A spring assembly includes a hook having a frame fixing part fixed on the mask frame and a spring fixing part and a spring fixed to the spring fixing part. The hook has a cut-away portion defined by cutting a portion of the frame fixing part. The cut-away portion forms a welding portion for welding the hook to the mask frame.

Abstract: A tension mask frame assembly for a color cathode-ray tube, including a tension mask, a frame and a vibration prevention unit, is provided. In this tension mask frame assembly, the tension mask has a slotted portion in which a plurality of electron beam passing holes are formed and a non-slotted portion located on the edge of the slotted portion. The frame supports two facing sides of the tension mask to apply a tensile force to the tension mask. The vibration prevention unit includes a damper having first and second attenuation portions that are maintained at a predetermined angle to form an insertion portion into which the edges of the tension mask not supported by the frame are inserted, and a support member for suspending the damper from the edges of the tension mask by passing through the first and second attenuation portions and the edges of the tension mask inserted into the insertion portion formed by the first and second attenuation portions.

Abstract: A color selection apparatus includes a frame comprising a pair of supporting members disposed in parallel with each other and a pair of elastic members disposed between and coupled to the supporting members. Each of the elastic members is formed of a hollow tube. A mask is coupled to the supporting members while being applied with a predetermined tension, and exhaust openings are formed for exhausting remaining alien substances from within the elastic members during an assembling process of the color selection apparatus. The exhaust openings are formed on each of the elastic members at a portion adjacent to where the elastic members are coupled to the supporting members.

Abstract: A tension mask frame assembly for a color cathode ray tube, including: a tension mask having a plurality of strips on which slots are formed being separated a predetermined distance from each other on a thin plate, real bridges for partitioning slots at a predetermined pitch interval by connecting adjacent ones of a plurality of strips to each other; and a frame which supports the corresponding edges of the tension mask, whereby the vertical pitch of the real bridges becomes smaller, such as in a stepwise relation, in a direction from the center portion of the tension mask to the peripheral portion of the tension mask.

Abstract: A frequency detecting circuit is provided that includes a level shift detecting unit for generating pulse signals of a certain pulse width at each level shifting of input clock signals and a level detecting unit. The level detecting unit includes a charging unit and a discharging unit. The discharging unit is activated by the pulse signals of the level shift detecting unit to discharge the charges of the charging unit. An inverter having a logic threshold voltage receives electrical signals in accordance with the charged level of the charging unit to output a signal indicative of the frequency of the input clock signals.