Shadow mask for color cathode-ray tube
AssigneeLG Electronics Inc.
InventorsSung Dae Kim, Sang Hu Park
Life of this patent
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Abstract
The present invention relates to a shadow mask comprising an effective surface including electron beam passage holes all over, an ineffective surface having a certain width surrounding the circumference of the effective surface, a skirt portion curved formed on the circumference of the ineffective surface, and concave-compressed beads formed on the ineffective surface along the skirt portion in order to improve the stiffness of the effective surface. The present invention can prevent distortions of a screen by forming the beads on the ineffective surface which is capable of improving stiffness of the shadow mask by increasing a lot value of the section modulus performing a function resisting the relative vibration occurred between the effective surface and skirt portion.
Claims27
A shadow mask for a color CRT, comprising:
- an effective surface formed with electron beam passage holes;
- an ineffective surface having a certain width surrounding a circumference of the effective surface;
- a skirt portion formed on the circumference of the ineffective surface with a predetermined height, wherein the skirt portion is a separate plane from the ineffective surface;
- and
- a plurality of concave-compressed beads formed from the ineffective surface to the skirt portion with two steps approximately parallel to the ineffective surface within each concave-compressed bead.
A shadow mask for a cathode ray tube, comprising:
- a first portion with holes for electron beam passage;
- a second portion surrounding outer edges of the first portion;
- a skirt portion formed along outer edges of the second portion;
- and
- a plurality of concave-compressed beads beads formed on both the second portion and the skirt portion so as to have two steps, wherein the beads are configured to provide strength and stiffness to the shadow mask, and wherein the second portion and the skirt portion are on separate planes.
A cathode ray tube that includes a shadow mask, wherein the improvement comprises a shadow mask having:
- an effective region having a plurality apertures therethrough;
- an ineffective portion separate from the effective portion in the same general plane as the effective region;
- and
- a skirt surrounding a circumference of the effective region, the skirt having a portion that extends approximately perpendicular to the plane of the effective region, wherein a plurality of indentations are formed in the skirt, each indentation extending into both the ineffective portion and the portion of the skirt so as to have at least two plane surfaces approximately parallel to each of the ineffective portion and the portion of the skirt, respectively, within each indention.
A shadow mask for a color CRT, comprising:
- an effective surface formed with electron beam passage holes;
- an ineffective surface having a certain width and surrounding a circumference of the effective surface;
- a skirt portion formed on a circumference of the ineffective surface with a predetermined height;
- and
- a plurality of concave-compressed beads respectively formed with at least two steps inside the concave-compressed beads, the steps being stepped from the ineffective surface to the skirt portion.
Dependencies are inferred from the claim text.