METHOD AND APPARATUS FOR MAKING COLOUR CATHODE-RAY TUBE

• Main Author: KAKUICHIRO HOSOKOSHI
• Format: Patent
• Language: English
• Published: 10.05.1972
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRICITY

1,273,459. Luminescent screens. MATSUSHITA ELECTRONICS CORP. 23 Oct., 1970 [30 Oct., 1969], No. 50516/70. Heading HID. In the manufacture of a multi-dot colour screen by a photo-resist process, the light source is a point source which is rotated to form an effective annular source. In Fig. 4 the light source is a glass rod 11 illuminated at its lower end by an ultra-violet lamp (not shown) and mounted eccentrically on a rotating shaft 16 so that the tip 12 describes a circular path. As illustrated, the light passing through an aperture 7 in a shadow mask on to the emulsion 9 has a maximum intensity in a central area 14 which is separated from a penumbra 141 by a sharp boundary 1411; consequently the penumbral regions 141 can be dissolved away to leave well-defined circular dot portions of smaller diameter than the apertures 7. The dot diameter is smaller the larger the diameter of the circle described by the tip 12 which may be larger than the diameter of the aperture 7.