Color cathode ray tube

1. A color cathode ray tube comprising:

a panel, said panel including an outer surface which is substantially flat and an inner surface on which a screen composed of a black layer and red, green and blue phosphors is formed;

wherein a screen transmittance of the panel equals to (a width of the red phosphor+a width of the green phosphor+a width of the blue phosphor)/(the widths of the red, green and blue phosphors+widths of the black layers between the red, green and blue phosphors)×100, and wherein said screen transmittance of the panel increases and then decreases along a line from a center portion to a peripheral portion of the panel.

2. The cathode ray tube of claim 1 , wherein the screen transmittance of the panel satisfies the following condition;

STM HALF ≧STM C STM HALF ≧STM E

wherein STM C is a screen transmittance at the center portion of the panel, STM E is a screen transmittance at the peripheral portion, and STM HALF is a screen transmittance at a point positioned about ½ the distance between the center portion and the peripheral portion.

3. The cathode ray tube of claim 1 , wherein the screen transmittance of the panel is maximized at a doming portion, and wherein the doming portion is a region extending along a major axis from ⅖ to ⅘ and extending along a minor axis from ⅛ to ⅞ on a basis of ½ of the surface of an effective surface portion of the panel in which the screen is formed.

4. The cathode ray tube of claim 1 , wherein the screen transmittance in the center portion of the panel is 60% or lower.

5. The cathode ray tube of claim 1 , wherein the screen transmittance of the panel is increases from the center portion of the panel to a long side portion of the panel along a major axis of the panel.

6. The cathode ray tube of claim 1 , wherein,

0.94 <STMv/STMc ≦1.16, and

0.94 ≦STM V /STM C ≦1.16, and

0.94 ≧STM H /STM C ≦1.16,

wherein STM C is a screen transmittance of the center of the panel, STM V is a screen transmittance of a long side portion, and STM H is a screen transmittance of a short side portion.

7. The cathode ray tube of claim 1 , wherein:

1.00 ≦STM DO /STM C ≦1.13,

wherein a doming portion is a region extending along a major axis from ⅖ to ⅘ and extending along a minor axis from ⅛ to ⅞ On a basis of ½ of the surface of an effective surface portion of the panel in which the screen is formed, STM C is a screen transmittance of the center of the panel, and STM DO is a screen transmittance of the doming portion.

8. The cathode ray tube of claim 1 , wherein,

1.05 W PDO /W PC ≦1.25,

wherein the doming portion is a region extending along a major axis from ⅖ to ⅘ and extending along a minor axis from ⅛ to ⅞ On a basis of ½ of the surface of an effective surface portion of the panel in which the screen is formed, W PC is a width of the phosphor at the center portion of the panel, and W PD is a width of the phosphor at the doming portion of the panel.

9. The cathode ray tube of claim 1 , wherein,

0.90 ≦W PV /W PC ≦1.1.0,

wherein W PC is a width of the phosphor at the center portion of the panel, and W PV is a width of the phosphor at a long side portion of the panel.

10. A color cathode ray tube comprising:

a panel, said panel including an outer surface which is substantially flat and an inner surface on which a screen composed of red, green and blue phosphors and black layer;

wherein a screen transmittance of the panel satisfies the following conditions:

STM HALF ≧STM C , and

STM HALF ≧STM H ;

wherein said screen transmittance of the panel equals to (a width of the red phosphor+a width of the green phosphor+a width of the blue phosphor)/(the widths of the red, green and blue phosphors+widths of the black layers between the red, green and blue phosphors)×100,

wherein STM C is a screen transmittance at a center portion of the panel, STM H is a screen transmittance at a short side portion of the panel, and STM HALF is a screen transmittance at a point positioned about ½ of the distance between the center portion and the short side portion of the panel.

11. The cathode ray tube of claim 10 , wherein a glass transmittance of the panel is 41–79%.

12. The cathode ray tube of claim 10 , wherein a screen pitch of the screen is increased from the center portion of the panel to a peripheral portion of the panel.

13. The cathode ray tube of claim 10 , wherein a width of the phosphor of the screen increases from the center portion of the panel to a peripheral portion of the panel along a major axis of the panel.

14. The cathode ray tube of claim 10 , wherein:

1.4 ≦PH E /PH C ≦1.7,

wherein PH C is a screen pitch of the phosphor at the center portion of the panel and PH E is a screen pitch of the phosphor at a peripheral portion of the panel.

15. The cathode ray tube of claim 10 , wherein:

1.27 ≦W PD /W PC 1.67,

wherein W PC is a width of the phosphor at the center portion of the panel, and W PD is a width of the phosphor at a corner portion of the panel.

16. The cathode ray tube of claim 10 , wherein:

1.27 ≦W PH /W PC 1.53,

wherein W PC is a width of the phosphor at the center portion of the panel, and W PH is a width of the phosphor at the short side portion of the panel.

17. The cathode ray tube of claim 10 , wherein a radius of curvature of the outer surface of the panel is 30,000 mm or longer.

18. The cathode ray tube of claim 10 , wherein the inner surface of the panel has a radius of curvature in a range of about 1.2R to 8R where R is obtained by multiplying a diagonal length of an effective surface of the panel in which the phosphor screen is formed by 1.767.

19. The cathode ray tube of claim 10 , wherein a wedge ratio which is a ratio between a thickness of glass at the center of the panel and a thickness of glass at a peripheral portion of the panel is about 140% or higher.