Cathode ray tube

Abstract

A cathode ray tube includes a panel having a substantially flat outer surface and an inner curved surface with a phosphor screen. The panel has a substantially rectangular effective screen portion with two long sides parallel to each other, two short sides parallel to each other and four rounded edges interconnecting each long side and the neighboring short side. The effective screen portion is structure such that a first line V1 interconnecting centers of the long sides, a second line H1 interconnecting centers of the short sides and a third line D1 interconnecting centers of the rounded edges opposite to each other meet at a point. The effective screen portion has a first thickness Tv at the centers of the long sides, a second thickness Th at the centers of the short sides, a third thickness Td at the centers of the edges and a fourth thickness Tc at the meeting point of the all three lines V1, H1 and D1. A shadow mask is disposed within the panel so that the shadow mask faces the inner curved surface of the panel. The shadow mask has a curvature corresponding to the inner curved surface of the panel. The ratio of the second thickness Th to the third thickness Td while subtracting the fourth thickness Tc from each thickness satisfies the following condition: 0.75(Th−Tc)/Td−Tc)≦0.85, and the ratio of the first thickness Tv to the thickness Td while subtracting the fourth thickness Tc from each thickness satisfies the following condition: 0.75≦(Tv−Tc)/(Td−Tc)≦0.85.

1. A cathode ray tube comprising:
 a panel having a substantially flat outer surface and an inner curved surface with a phosphor screen, the panel having a substantially rectangular effective screen portion with two long sides parallel to each other, two short sides parallel to each other and four rounded edges each interconnecting each  a long side and the  a neighboring short side respectively, the effective screen portion being structured such that a first line V 1  interconnecting centers of the long sides, a second line H 1  interconnecting centers of the short sides and a third line D 1  interconnecting centers of the rounded edges opposite to each other meet at a point, the effective screen portion having a first thickness Tv at the centers of the long sides, a second thickness Th at the centers of the short sides, a third thickness Td at the centers of the edges and a fourth thickness Tc at the meeting point of the first to third lines V 1 , H 1  and D 1 ;  
 wherein the ratio of the second thickness Th to the third thickness Td while subtracting the fourth thickness Tc from each thickness satisfies the following condition: 0.75≦(Th−Tc)/(Td−Tc)≦0.85, and the ratio of the first thickness Tv to the third thickness Td while subtracting the fourth thickness Tc from each thickness satisfies the following condition: 0.75≦(Tv−Tc)/(Td−Tc)≦0.85.  
 
     
     
       2. The cathode ray tube of  claim 1  wherein the ratio of the third thickness Td to the fourth thickness Td satisfies the following condition: Td/Tc≦2. 
     
     
       3. The cathode ray tube of  claim 1  wherein the effective screen portion of the panel has a first curvature radius Rv at the first line V 1 , curvature radius Rh at the second line H 1  and a third curvature radius Rd at the third line D 1 , and the curvature radii Rv, Rh and Rd have an inter-relation of Rv≦Rd≦Rh. 
     
     
       4. A cathode ray tube comprising:
 a panel having a substantially flat outer surface and an inner curved surface with a phosphor screen, the panel having a substantially rectangular effective screen portion with two long sides parallel to each other, two short sides parallel to each other and four rounded edges each interconnecting each  a long side and the  a neighboring short side respectively, the effective screen portion being structured such that a first line V 1  interconnecting centers of the long sides, a second line H 1  interconnecting centers of the short sides and a third line D 1  interconnecting centers of the rounded edges opposite to each other meet at a point, the effective screen portion having a first thickness Tv at the centers of the long sides, a second thickness Th at the centers of the short sides, a third thickness Td at the centers of the edges and a fourth thickness Tc at the meeting point of the first to third lines V 1 , H 1  and D 1 ;  
 wherein the ratio of the second thickness Th to the fourth thickness Tc satisfies the following condition: 1.4≦Th/Tc≦1.6, and the ratio of the third thickness Td to the fourth thickness Tc satisfies the following condition: 1.7≦Td/Tc≦2.0.  
 
     
     
       5. The cathode ray tube of  claim 4  wherein the effective screen portion of the panel has a first curvature radius Rv on the first line V 1 , a second curvature radius Rh on the second line H 1  and a third curvature radius Rd on the third line D 1 , and the curvature radii Rv, Rh and Rd have an inter-relation of Rv≦Rd≦Rh. 
     
     
       6. The cathode ray tube of  claim 5  wherein the inner curved surface of the panel has a unique curvature radius or varying curvature radii at different positions. 
     
     
       7. The cathode ray tube of  claim 6  wherein the curvature radii Rv, Rh, and Rd are all either constant throughout the inner surface of the panel or varying at different positions. 
     
     
       8. A cathode ray tube comprising:
 a panel having a substantially flat outer surface and an inner curved surface with a phosphor screen, the panel having a substantially rectangular effective screen portion with two first sides parallel to each other, two second sides parallel to each other, the second two sides being shorter than the first two sides, and four rounded edges each interconnecting one of the first sides with one of the second sides, the effective screen portion having a first thickness Tv at a center of one of the first sides, a second thickness Th at a center of one of the second sides, a third thickness Td at a center of one or the rounded edges and a fourth thickness Tc at a center of the effective screen portion; and  
 wherein a thickness ratio of the effective screen portion satisfies the following conditions: 0.75≦(Th−Tc)/(Td−Tc)≦0.85, and 0.75≦(Tv−Tc)/(Td−Tc)≦0.85.  
 
     
     
       9. The cathode ray tube of  claim 8  wherein the thickness ratio of the effective screen portion further satisfies the following condition: Td/Tc≦2. 
     
     
       10. The cathode ray tube of  claim 8  wherein the effective screen portion of the panel has a curvature radius along a first line between the centers of the first sides, a curvature radius along a second line between the centers of the second sides, and a curvature radius along a diagonal line between the centers of two of the rounded corners edges, wherein the maximum curvature of radius along the first line and the minimum curvature of radius along the second line are equal to the curvature of radius along the diagonal line. 
     
     
       11. A cathode ray tube comprising:
 a panel having a substantially flat outer surface and an inner curved surface with a phosphor screen, the panel having a substantially rectangular effective screen portion with two first sides parallel to each other, two second sides parallel to each other, the second two sides being shorter than the first two sides, and four rounded edges each interconnecting one of the first sides with one of the second sides, the effective screen portion having a first thickness Tv at a center of one of the first sides, a second thickness Th at a center of one of the second sides, a third thickness Td at a center of one of the edges and a fourth thickness Tc at a center of the effective screen portion; and  
 wherein a thickness ratio of the effective screen portion satisfies the following conditions: 1.4≦Th/Tc≦1.6, and 1.7≦Td/Tc≦2.0.  
 
     
     
       12. The cathode ray tube of  claim 11  wherein the effective screen portion of the panel has a curvature radius along a first line between the centers of the first sides, a curvature radius along a second line between the centers of the second sides, and a curvature radius along a diagonal line between the centers of two of the rounded corners edges, wherein the maximum curvature of radius along the first line and the minimum curvature of radius along the second line are equal to the curvature of radius along the diagonal line. 
     
     
       13. A cathode ray tube comprising:
   a panel having a substantially flat outer surface and an inner curved surface with a phosphor screen, the panel having an effective screen portion with two first sides substantially parallel to each other, two second sides substantially parallel to each other and edges, the edges located where each said first side and each neighboring said second side meet, the effective screen portion being structured such that a first line V 1  interconnecting centers of the first sides, a second line H 1  interconnecting centers of the second sides and a third line D 1  interconnecting the edges which are opposite to each other, meet at a point, the effective screen portion having a first thickness Tv at the centers of the first sides, a second thickness Th at the centers of the second sides, a third thickness Td at the centers of the edges and a fourth thickness Tc at the meeting point of the first, second and third lines V 1 , H 1  and D 1 ;        wherein the ratio of the second thickness Th to the third thickness Td while subtracting the fourth thickness Tc from each thickness satisfies the following condition:  0 . 75 ≦ ( Th−Tc )/( Td−Tc ) ≦ 0 . 85 , and the ratio of the first thickness Tv to the third thickness Td while subtracting the fourth thickness Tc from each thickness satisfies the following condition:  0 . 75 ≦ ( Tv−Tc )/( Td−Tc ) ≦ 0 . 85 .     
     
     
       14. The cathode ray tube of  claim 13  wherein the ratio of the third thickness Td to the fourth thickness Td satisfies the following condition: Td/Tc≦ 2 . 
     
     
       15. The cathode ray tube of  claim 13  wherein the effective screen portion of the panel has a first curvature radius Rv at the first line V 1 , curvature radius Rh at the second line H 1  and a third curvature radius Rd at the third line D 1 , and the curvature radii Rv, Rh and Rd have an inter- relation of Rv≦Rd≦Rh.   
     
     
       16. A cathode ray tube comprising:
   a panel having a substantially flat outer surface and an inner curved surface with a phosphor screen, the panel having an effective screen portion with two first sides substantially parallel to each other, two second sides substantially parallel to each other and edges, the edges located where each said first side and each neighboring said second side meet, the effective screen portion being structured such that a first line V 1  interconnecting centers of the first sides, a second line H 1  interconnecting centers of the second sides and a third line D 1  interconnecting the edges which are opposite to each other, meet at a point, the effective screen portion having a first thickness Tv at the centers of the long sides, a second thickness Th at the centers of the short sides, a third thickness Td at the centers of the edges and a fourth thickness Tc at the meeting point of the first, second and third lines V 1 , H 1  and D 1 ;        wherein the ratio of the second thickness Th to the fourth thickness Tc satisfies the following condition:  1 . 4 ≦Th/Tc≦ 1 . 6 , and the ratio of the third thickness Td to the fourth thickness Tc satisfies the following condition:  1 . 7 ≦Td/Tc≦ 2 . 0 .     
     
     
       17. The cathode ray tube of  claim 16  wherein the effective screen portion of the panel has a first curvature radius Rv on the first line V 1 , a second curvature radius Rh on the second line H 1  and a third curvature radius Rd on the third line D 1 , and the curvature radii Rv, Rh and Rd have an inter- relation of Rv≦Rd≦Rh.   
     
     
       18. The cathode ray tube of  claim 17  wherein the inner curved surface of the panel has a unique curvature radius or varying curvature radii at different positions. 
     
     
       19. The cathode ray tube of  claim 18  wherein the curvature radii Rv, Rh, and Rd are all either constant throughout the inner surface of the panel or varying at different positions. 
     
     
       20. A cathode ray tube comprising:
   a panel having a substantially flat outer surface and an inner curved surface with a phosphor screen, the panel having an effective screen portion with two first sides substantially parallel to each other, two second sides substantially parallel to each other, and edges, the edges located where each said first side and each neighboring said second side meet, the effective screen portion having a first thickness Tv at a center of one of the first sides, a second thickness Th at a center of one of the second sides, a third thickness Td at one of the edges and a fourth thickness Tc at a center of the effective screen portion; and        wherein a thickness ratio of the effective screen portion satisfies the following conditions:  0 . 75 ≦ ( Th−Tc )/( Td−Tc ) ≦ 0 . 85 , and  0 . 75 ≦ ( Tv−Tc )/( Td−Tc ) ≦ 0 . 85 .     
     
     
       21. The cathode ray tube of  claim 20  wherein the thickness ratio of the effective screen portion further satisfies the following condition: Td/Tc≦ 2 . 
     
     
       22. The cathode ray tube of  claim 20  wherein the effective screen portion of the panel has a curvature radius along a first line between the centers of the first sides, a curvature radius along a second line between the centers of the second sides, and a curvature radius along a diagonal line between two of the edges, wherein the maximum curvature of radius along the first line and the minimum curvature of radius along the second line are equal to the curvature of radius along the diagonal line. 
     
     
       23. A cathode ray tube comprising:
   a panel having a substantially flat outer surface and an inner curved surface with a phosphor screen, the panel having an effective screen portion with two first sides substantially parallel to each other, two second sides substantially parallel to each other, and edges, the edges located where each said first side and each neighboring said second side meet, the effective screen portion having a first thickness Tv at a center of one of the first sides, a second thickness Th at a center of one of the second sides, a third thickness Td at a center of one of the edges and a fourth thickness Tc at a center of the effective screen portion; and        wherein a thickness ratio of the effective screen portion satisfies the following conditions:  1 . 4 ≦Th/Tc≦ 1 . 6 , and  1 . 7 ≦Td/Tc≦ 2 . 0 .     
     
     
       24. The cathode ray tube of  claim 23  wherein the effective screen portion of the panel has a curvature radius along a first line between the centers of the first sides, a curvature radius along a second line between the centers of the second sides, and a curvature radius along a diagonal line between two of the edges, wherein the maximum curvature of radius along the first line and the minimum curvature of radius along the second line are equal to the curvature of radius along the diagonal line.