Color cathode-ray tube

A color cathode-ray tube, comprising:

• a mask frame with at least a pair of opposed supporters, which is formed in a substantially rectangular frame shape;
• and
• a shadow mask functioning as a color selection electrode stretched and held by the supporters while being provided with a tensile force,
• wherein each of the pair of opposed supporters is a member with a substantially L-shaped cross-section and is obtained by:
• forming of a strip plate material by rolling of a metal material, the strip plate material having a middle part, thinner thickness-deviation portions on both sides of the middle part, and a thick stripe portion at a predetermined position in the middle part corresponding to an outer corner of a bent and deformed portion to be formed;
• and
• then bending and deforming of the strip plate material in its width direction at a position of the thick stripe portion by roll forming to form the bent and deformed portion.

A color cathode-ray tube, comprising:

• a mask frame with at least a pair of opposed supporters, which is formed in a substantially rectangular frame shape;
• and
• a shadow mask functioning as a color selection electrode stretched and held by the supporters while being provided with a tensile force,
• wherein each of the pair of opposed supporters is a member with a substantially L-shaped cross-section and is obtained by a process in which while thinner thickness-deviation portions are formed on both sides of a middle part of a metal material by rolling of the metal material, the metal material is bent and deformed in its width direction by roll forming to form a bent and deformed portion in the middle part.

A color cathode-ray tube, comprising:

• a mask frame with at least a pair of opposed supporters, which is formed in a substantially rectangular frame shape;
• and
• a shadow mask functioning as a color selection electrode stretched and held by the supporters while being provided with a tensile force,
• wherein each of the pair of opposed supporters is a member with a substantially L-shaped cross-section and is obtained by a process in which while rolling a metal material to form thinner thickness-deviation portions on both sides of a middle part of the metal material and a thick stripe portion at a predetermined position in the middle part corresponding to an outer corner of a bent and deformed portion to be formed, the metal material is bent and deformed in its width direction at a position of the thick stripe portion by roll forming to form the bent and deformed portion.