The curvature radius of outer surface of effective part of panel is 10000mm or more; if setting the length of porous area of shade frame along the X-axle (main axle) is 2L, s is the variable that less than1 and higher than 0, the sagging difference of porous area at the point X=sL relative to the X=0 is deltaZ01(s), and the sagging difference of porous area at the point X=L relative to the X=sL is deltaZ02(s); the sagging difference of porous area at the point X=sL at long length relative to the point X=0 and the sagging difference of X=L at long length relative to the point X=sL are deltaZ11(s) and deltaZ12(s); when definingalpha(s) =( deltaZ01(s)/ deltaZ11(s))/( delta Z02(s)/ deltaZ12(s)), at least part of 0.2<=s<=0.8 meets dalpha(s)/ds>=0.4; therefore, the invention can provide a colorful kinescope, with better forming property and high strength. |