Cathode-ray tube
AssigneeKabushiki Kaisha Toshiba
InventorsNorio Shimizu, Munechika Tani, Fumiaki Nihei
Life of this patent
Estimating the term…
Abstract
A shadow mask has a major axis H and a minor axis V that intersect at right angles with each other, and a curvature along the major axis is set to satisfy the following relationships, Cxm0<Cxmv, and Cxmd<Cxmh where Cxm0 is a curvature at an origin O where the major axis and the minor axis intersect at right angles, Cxmv is a curvature at a point (0, Ymvi) that is located towards a long side from a point of at least ¾ of a distance from the origin on the minor axis to an end of an effective dimension, Cxmh is a curvature at a point (Xmhi, 0) that is located in a region of 2/4 to ¾ of a distance from the origin on the major axis to an end of an effective dimension, and Cxmd is a curvature at a coordinate point (Xmhi, Ymvi).
Claims6
A cathode-ray tube comprising:
- an envelope including a substantially rectangular panel with a substantially flat outer surface, and a funnel that is coupled to the panel;
- a phosphor screen that is disposed on an inner surface of the panel;
- an electron gun assembly that is disposed within the envelope and emits an electron beam towards the phosphor screen;
- and
- a substantially rectangular shadow mask including a mask body, which is disposed to face the phosphor screen and has a plurality of electron beam passage holes, and a mask frame that supports a peripheral part of the mask body,
- wherein the shadow mask is formed of a material that essentially comprises iron,
- the shadow mask has a major axis and a minor axis that intersect at right angles with each other, and a curvature along the major axis is set to satisfy the following relationships,
- Cxm0<Cxmv, and Cxmd<Cxmh
- where Cxm0 is a curvature at an origin (0, 0) where the major axis and the minor axis intersect at right angles;
- Cxmv is a curvature at a point (0, Ymvi) that is located towards a long side from a point of at least ¾ of a distance from the origin on the minor axis to an end of an effective dimension;
- Cxmh is a curvature at a point (Xmhi, 0) that is located in a region of 2/4 to ¾ of a distance from the origin on the major axis to an end of an effective dimension;
- and Cxmd is a curvature at a coordinate point (Xmhi, Ymvi), and
- the shadow mask is configured to satisfy the following relationship,
- Zmhi<Xmhi2×Zmho/Xmho2
- where Xmho is a distance between the origin on the major axis and the end of the effective dimension;
- Zmho is a difference in height along a tube axis between the origin on the major axis and the end (Xmho, 0) of the effective dimension;
- and Zmhi is a difference in height along the tube axis between the origin on the major axis and a point (Xmhi, 0).
A cathode-ray tube comprising:
- an envelope including a substantially rectangular panel with a substantially flat outer surface, and a funnel that is coupled to the panel;
- a phosphor screen that is disposed on an inner surface of the panel;
- an electron gun assembly that is disposed within the envelope and emits an electron beam towards the phosphor screen;
- and
- a substantially rectangular shadow mask including a mask body, which is disposed to face the phosphor screen and has a plurality of electron beam passage holes, and a mask frame that supports a peripheral part of the mask body,
- wherein the inner surface of the panel has a major axis and a minor axis that intersect at right angles with each other, and a curvature along the major axis is set to satisfy the following relationships,
- Cxp0<Cxpv, and Cxpd<Cxph
- where Cxp0 is a curvature at an origin (0, 0) where the major axis and the minor axis intersect at right angles;
- Cxpv is a curvature at a point (0, Ypvi) that is located towards a long side from a point of at least ¾ of a distance from the origin on the minor axis to an end of an effective dimension;
- Cxph is a curvature at a point (Xphi, 0) that is located in a region of 2/4 to ¾ of a distance from the origin on the major axis to an end of an effective dimension;
- and Cxpd is a curvature at a coordinate point (Xphi, Ypvi), and
- the inner surface of the panel is configured to satisfy the following relationship,
- Zphi<Xphi2×Zpho/Xpho2
- where Xpho is a distance between the origin on the major axis and the end of the effective dimension;
- Zpho is a difference in height along a tube axis between the origin on the major axis and the end (Xpho, 0) of the effective dimension;
- and Zphi is a difference in height along the tube axis between the origin on the major axis and a point (Xphi, 0).
Dependencies are inferred from the claim text.