Color cathode ray tube including mask frame with protruding portions

A color cathode ray tube comprising:

• an envelope including a panel having an effective substantially rectangular portion in which a phosphor screen is formed on an inner surface thereof and a skirt portion provided on a periphery of the panel, and a funnel attached to the skirt portion;
• a shadow mask arranged in the envelope to oppose the phosphor screen;
• and
• an elastic support elastically supporting the shadow mask relative to the skirt portion;
• the shadow mask including a substantially rectangular mask body having a number of electron beam passage apertures, and a substantially rectangular mask frame having four side walls supporting the periphery of the mask body,
• each of at least two side walls opposing each other of the mask frame having a protruding portion protruding in a direction away from the mask body and defining a gap between said side wall and the mask body, and a bead protruding toward the inside of the mask frame from the protruding portion without contacting with the mask body.

A color cathode ray tube comprising:

• an envelope including a panel having an effective substantially rectangular portion in which a phosphor screen is formed on an inner surface thereof and a skirt portion provided on a periphery of the panel, and a funnel attached to the skirt portion;
• a shadow mask arranged in the envelope to oppose the phosphor screen;
• and
• an elastic support elastically supporting the shadow mask relative to the skirt portion;
• the shadow mask including a substantially rectangular mask body having a number of electron beam passage apertures, and a substantially rectangular mask frame having four side walls supporting the periphery of the mask body,
• each of at least two side walls opposing each other of the mask frame having a central connecting portion which is provided at a central portion of the side wall in a lengthwise direction thereof and fixed to the mask body;
• a pair of end connecting portions which are located on both ends of the side wall in the lengthwise direction thereof and fixed to the mask body;
• a middle connecting portion which is located between the central connecting portion and each end connecting portion and fixed to the mask body;
• a pair of first protruding portions each of which is formed between the central connecting portion and the middle connecting portion and protrudes in a direction away from the mask body;
• and a pair of second protruding portions each of which is formed between the middle connecting portion and the end connecting portion and protrudes in a direction away from the mask body;
• each of the first protruding portions defining a gap between the side wall and the mask body, whose width continuously increases from the central connecting portion up to the middle connecting portion, and each of the second protruding portions defining a gap between the side wall and the mask body, whose width continuously increases from the middle connecting portion up to the end connecting portion.