Patent ID: 7301267
Filing Date: 2007-11-27
Classification: H01J

Abstract:
1. A shadow mask that comprises a mask body in which a large number of slots are made in a horizontal direction and a vertical direction, and that allows electron beams to form roughly rectangular beam spots on a fluorescent screen of a cathode ray tube, each one of the slots made in the mask body having a roughly rectangular backside opening on a side on which electron beams are incident, a roughly rectangular front-side opening on a side from which electron beams emerge, and a through-hole that connects the backside opening and the front-side opening with each other, the mask body having a center point situated in a center of a mask body plane, a horizontal axis passing through the center of the mask body, horizontally extending along the mask body plane, a vertical axis passing through the center of the mask body, vertically extending along the mask body plane, and two diagonal axes passing through the center of the mask body, diagonally extending along the mask body plane, a horizontal bridge part extending in the horizontal direction being provided between the front-side openings of each two first slots, of the slots made in the mask body, that are arranged adjacently to each other in the vertical direction, and between each second slot, of the slots made in the mask body, that is situated at least on either of the diagonal axes of the mask body but in such a position that an angle at which the electron beams enter the second slot is 20 degrees or more and a third slot that is arranged adjacently to the second slot in the vertical direction, a connecting part connecting a peripheral-side vertical outer edges of the front-side openings of the second and third slots, the connecting part being formed on a front-side of the mask body, while not affecting a back-side of the mask body so that the connecting part runs through the horizontal bridge part formed between the front-side openings of the second and third slots, the connecting part being formed along and inward, to a center side, from a vertical line connecting the peripheral-side vertical outer edges of front-side openings of the second and third slots to be connected by the connecting part so that the relationship 0<D1<T is fulfilled, where T (μm) is a distance between the peripheral-side vertical outer edges of the front side openings and the peripheral-side vertical outer edges of through-holes of the second and third slots to be connected by the connecting part, and D1 (μm) is a horizontal width of the connecting part.