Kabushiki Kaisha Toshiba

Yasushi Magaki

Yasuhisa Ohtake

Hiroshi Tanaka

Seiji Sagou

Seiji Sago

Mitsuaki Yamazaki

A shadow mask includes a mask substrate having vertical and horizontal axes passing through a center of the substrate, and a number of substantially rectangular apertures. The apertures are arranged so that a plurality of vertical trains of apertures extending parallel to the vertical axis are arranged at predetermined intervals in the direction of the horizontal axis. Each of the apertures other than the apertures located on the vertical axis has a pair of outer corners distant from the vertical axis, a pair of inner corners less distant from the vertical-axis side, and a pair of bulging portions extending from the outer corners, respectively, outward in the horizontal direction. The farther each of the apertures is located from the vertical axis, the longer the bulging portions extend outward.

Shadow mask for color cathode ray tube, shadow mask printing negative

Shadow mask for color cathode ray tube

An aperture pattern printing plate for manufacturing a shadow mask having an opaque layer form in parts on a surface of a transparent plate. The parts of the opaque layer corresponding to apertures in an effective area of the shadow mask. The opaque layer projecting from the transparent plate, and having a thickness of 30 to 50 .mu.m.

Aperture pattern printing plate

An aperture pattern-printing plate used for manufacturing a shadow mask, which comprises a transparent substrate, and an emulsion layer which is formed on the transparent substrate and which is opaque at portions corresponding to apertures of the shadow mask and transparent at other portions, wherein the emulsion layer is overlaid with at least one of the following a substantially-amorphous, transparent scratch-preventing film obtained by hydrolysis and condensation of metal alcoholate and having a thickness of not more than 1.5 .mu.m, and a foreign matter-preventing film formed substantially of silicone and having a thickness of not more than 0.5 .mu.m. The foreign matter-preventing film is formed on the scratch-preventing film if the foreign matter-preventing film and scratch-preventing film are both formed.

Aperture pattern-printing plate for shadow mask and method for

A method of manufacturing an aperture pattern printing plate in a limited number of steps using only one original printing plate. The method produces transparent portions on a portion of the printing plate corresponding to a non-effective area of a shadow mask, and opaque portions on a portion of the printing plate corresponding to an effective area of a shadow mask. The method has the steps of bringing a transparent plate having an unexposed transparent photosensitive layer formed on at least one of its principal surfaces into contact with an original plate having opaque areas corresponding to apertures in a to be constructed shadow mask. A first exposure is performed on the photosensitive layer through the original plate. The photosensitive layer is then developed to render exposed portions of the photosensitive layer opaque. These opaque portions are then etched away. A portion of the photosensitive layer corresponding to the non-effective area of a shadow mask is then covered to prevent exposure. A second exposure of the photosensitive layer is then performed; thereby achieving exposure of only the portion of the photosensitive layer corresponding to an effective area of a shadow mask. The photosensitive layer is then developed to render the exposed portions of the photosensitive layer opaque. By etching away the opaque portions produced after development of the first exposure, air passages are produced on the whole surface of the transparent plate.

Growing community of inventors

Fukaya, Japan

Yasushi Magaki