The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 04, 2007
Filed:
May. 31, 2005
Fumiaki Nihei, Ibaraki, JP;
Norio Shimizu, Ibaraki, JP;
Toshio Uchikawa, Ibaraki, JP;
Matsushita Toshiba Picture Display Co., Ltd., Osaka, JP;
Abstract
The radius of curvature of an outer surface of a panel useful portion is 10,000 mm or more. Assuming that a length of a perforated region of a shadow mask in an X-axis (major axis) direction is 2L, s is a variable satisfying 0<s<1, a sagging amount difference of the perforated region at a point of X=sL with respect to a point of X=0 on the X axis and a sagging amount difference of the perforated region at a point of X=L with respect to the point of X=sL on the X axis are ΔZ(s) and ΔZ(s), respectively, a sagging amount difference of the perforated region at the point of X=sL with respect to the point of X=0 on the long side and a sagging amount difference of the perforated region at the point of X=L with respect to the point of X=sL on the long side are ΔZ(s) and ΔZ(s), respectively, when α(s) represented by α(s)=(ΔZ(s)/ΔZ(s))/(ΔZ(s)/ΔZ(s)) is defined, dα(s)/ds≧0.4 is satisfied in at least a portion in a range of 0.2≦s≦0.8. Because of this, a color picture tube can be provided, which has satisfactory visibility, and less degradation in color purity caused by doming while having a shadow mask with excellent formability and strength.