CRT having color filter with a special green filter

Abstract

A color picture tube is disclosed, that comprises an outer sheath having a electron gun, the outer sheath being airtightly sealed, a face plate having light transmissivity and disposed on the front surface of the outer sheath, and a large number of red, blue, and green pixels regularly arranged inside the face plate, wherein the pixels have a fluorescent substance layer and a color filter, the fluorescent substance layer being lit by a radiation of an electron beam, the color filter being disposed between the fluorescent substance layer and the face palate, and wherein green pixels have a chromaticity that is plotted in the fourth quadrant of a coordinate system of a (L*a*b*) color system where a* is the horizontal axis and *b is the vertical axis when light of a standard light source C is reflected on the outside of the face plate.

What is claimed is:  
     
       1. A color picture tube, comprising: 
       a funnel having a neck portion;  
       an electron gun disposed in said neck portion  
       a light transmissive face plate disposed as a front surface of said funnel, said funnel and face plate forming an outer sheath of said tube that is airtightly sealed; and  
       a large number of red, blue, and green pixels regularly arranged inside said face plate,  
       wherein the pixels have a fluorescent substance layer and a color filter, the fluorescent substance layer being lit by a radiation of an electron beam, the color filter being disposed between the fluorescent substance layer and said face plate, and  
       wherein the green pixels have a chromaticity that is plotted in the fourth quadrant of a coordinate system of  second quadrant of a coordinate system of a (L*a*b*) color system where L* represents lightness, a* is the horizontal axis and b* is the vertical axis when light of a standard light source C is reflected on the outside of said face plate.  
     
     
       2. The color picture tube as set forth in  claim 1 , wherein the green pixels has a chromaticity that is plotted on a coordinate system of a (L*a*b*) color system where L* represents light a* is the horizontal axis and b* is the vertical axis so that the following relation is satisfied: 
       
         
           b*≦(−8/3)α*.  
         
       
     
     
       3. The color picture tube as set forth in  claim 1 , wherein the green pixels has a chromaticity that is plotted on a coordinate system of a (L*a*b*) color system where L* represents light a* is the horizontal axis and B* is the vertical axis so that the following relation is satisfied: 
       
         
           b*≦(−6/5)α*.  
         
       
     
     
       4. A color picture tube, comprising: 
       a light transmissive face plate having an effective display surface for displaying a picture;  
       a funnel, the front end of which is connected to the rear end of said face plate, the rear end of said funnel being narrow, said funnel being airtightly sealed with said face plate as a sheath of the color picture tube;  
       a fluorescent substance layer coated on the inner surface of the effective display surface of said face plate, said fluorescent substance layer having color fluorescent substances corresponding to red, blue, and green pixels;  
       a color filter disposed between said face plate and said fluorescent substance layer and having color cells corresponding to the red, blue, and green pixels; and  
       an electron gun disposed at the rear end of said funnel and adapted for radiating an electron beam to said fluorescent substance layer corresponding to a display picture,  
       wherein the color cells corresponding to the green fluorescent substance of said color filter include a pigment that is a mixture of Fe 2 O 3  particles and at least one selected from the group consisting of TiO 2 —NiO—CoO—ZnO particles, CoO—Al 2 O 3 —Cr 2 O 3 —TiO 2  particles, and CoO—Al 2 O 3 —Cr 2 O 3  particles.  
     
     
       5. The color picture tube as set forth in  claim 4 , wherein the color cells corresponding to the red fluorescent substances of said color filter include Fe 2 O 3  particles as a pigment. 
     
     
       6. The color picture tube as set forth in  claim 4 , 
       wherein the color cells corresponding to the blue fluorescent substance of said color filter include Al 2 O 3 —CoO particles as a pigment.