Patent ID: 6320305
Filing Date: 2001-11-20
Classification: H01J

Abstract:
A color cathode ray tube comprising:an envelope comprising a funnel and a panel including a substantially rectangular effective portion and a skirt portion provided at a peripheral portion of the effective portion, the effective portion having an inner surface on which a phosphor screen is formed, the funnel being joined to the skirt portion;a shadow mask arranged to oppose the phosphor screen; andan electron gun arranged in a neck of the funnel, for emitting electron beams onto the phosphor screen through the shadow mask;the shadow mask comprising:a substantially rectangular effective surface having a large number of electron beam passage apertures, for allowing the electron beams to pass therethrough, the effective surface having a center located on a tube axis, and a major axis and a minor axis extending perpendicular to each other through the center,a substantially rectangular mask frame attached to a peripheral portion of the mask body, and having a pair of long side walls extending substantially in parallel to the major axis of the effective surface and a pair of short side walls extending substantially in parallel to the minor axis of the effective surface, andelastic supporting members respectively provided on outer surfaces of the long side walls and short side walls of the mask frame, the elastic supporting members being respectively engaged with supporting pins provided on the skirt portion to support the shadow mask; andthe mask frame being formed to satisfy the following relationship:F1/(S1.times.t1).apprxeq.F2/(S2.times.t2)where S1 is an area of the outer surface of the long side wall of the mask frame, t1 is a thickness of the long side wall, S2 is an area of the outer surface of the short side wall, t2 is a thickness of the short side wall, F1 is a pushing pressure acting from the elastic member onto the long side wall when the elastic member is engaged with the supporting pin to support the shadow mask, and F2 is a pushing pressure acting from the elastic member onto the short side wall when the elastic member is engaged with the supporting pin to support the shadow mask.