Abstract: A method of manufacturing a luminescent screen of a shadow mask color tube. The phosphor dots on the screen which are separated by a light-absorbing material are smaller than the apertures in the shadow mask. The light-absorbing layer is first provided on the window and the luminescent materials are then provided successively. The inner surface of the window is such that undulations having a spatial frequency from 5 to 50 cm.sup.-.sup.1 or, in other words, wavelengths between 0.2 cm and 0.02 cm, show a depth of less than 1 micron.

Abstract: In the manufacture of screens for cathode-ray tubes, a substantial part of the screens being covered with a non-reflecting substance, hardened polyvinyl alcohol dots of relatively small diameter should be obtained by exposure via a mask with relatively large holes. Owing to an inadequate gradient of the photosensitive polyvinyl alcohol it is not possible to obtain dots of uniform size. The invention enables well-defined, uniform dots to be obtained by superposing a substance on the photosensitive layer which absorbs the light used during exposure, thereby decomposing into substances which do not or not substantially absorb this light. Thus, the effective gradient of the photosensitive polyvinyl alcohol is increased.

Abstract: A method of manufacturing an electrically conducting layer on an internal wall part of a cathode-ray tube wherein by the addition of an alkali or ammonium sulphate or nitrate to a suspension consisting of a conducting material and a binder, a suspension is obtained which, upon drying on the wall, provides a layer in which substantially no gas bubbles are formed during the firing of the tube.