Funnel for cathode ray tube
AssigneeNippon Electric Galss Co., Ltd.
InventorToshio Kunitake
Life of this patent
Estimating the term…
Abstract
In the funnel for use in cathode ray tubes, the thickness of the region ranging from the major axis L to the diagonal axis D is made substantially uniform by keeping the difference in thickness between the regions on the major axis L and the diagonal axis D within 0.3 mm. Another substantially uniform thickness region is formed in the region ranging from 90°−(d+α)° to the minor axis S by keeping the difference in thickness from the minor axis S within 0.3 mm. The thickness of the region on the major axis L is the same as the conventional one. Then the weight of the funnel can be reduced without sacrificing its mechanical strength.
Claims14
A funnel for a cathode ray tube comprising:
- a yoke portion at a smaller open-end side and a body portion at a larger open-end side, an arbitrary transverse cross-section (Ph) perpendicular to a center line X of said body portion being substantially rectangular having a major axis L, a minor axis S and a diagonal axis D,
- wherein, with said transverse cross-section (Ph) being virtually divided into four 90°-quadrants around said center line X, a thickness distribution at least in one of said quadrants is provided by |T(Dh)−T(Lh)|≦0.3 mm and T(Dh)>T(Sh), |T(θh)−T(Lh)|0.3 mm and |T(θh)−T(Dh) |≦0.3 mm in a 0°≦θ≦d° region, and |T(θh)−T(Sh)|≦0.3 mm in a (d+α)°≦θ≦90° region where 0°<α<(90−d)°;
- where θ(0°≦θ≦90°) is an angle measured from said major axis L in each quadrant, T(Lh) is a thickness of a region on said major axis L (θ=0°), T(Sh) is a thickness of a region on said minor axis S (θ=90°), T(Dh) is a thickness of a region on said diagonal axis D(θ=d°), and T(θh) is a thickness of a region at an arbitrary angle (θ).
Dependencies are inferred from the claim text.