Production of shadow mask pattern - in which sensitive surface on inner face of TV tube screen in illuminated through shadow mask and developed

摘要

A method for the production of a basic pattern for the phosphor screen of a colour television tube with a black matrix. A shadow mask (3) is fitted to the front screen of the tube (1), the inner surface of the screen having been coated with a light sensitive coating. The whole is placed on an illuminating support (A) so that an image of the pattern of the shadow mask is formed on the sensitive surface by means of the light source (4). A correction lens (5) is used to compensate for the curvature of the tube face. After exposure, the shadow mask is removed and the image on the light sensitive surface developed by suitable means.