SCREEN BOUNDARY STRUCTURE FOR MULTI-DEFLECTION CATHODE RAY TUBE

摘要

PURPOSE: A screen boundary structure for multi-deflection CRT is provided to achieve improved screen characteristics by preventing mixture of signal light and fluorescent light and damage of metal back. CONSTITUTION: A screen boundary structure comprises a boundary signal illuminance layer(14a) arranged at an inner surface of a shadow mask(14) on a screen boundary so as to allow for an incidence of an electron beam(20) and emit a signal light(14b); and a collector disposed at an outer surface of a funnel, and which collects the signal light emitted from the boundary signal illuminance layer and utilizes the collected signal as a control signal for an electron gun. Since the boundary signal illuminance layer is formed at the inner surface of the shadow mask, the collection of the signal light and fluorescent light has a predetermined difference in time, to thereby prevent mixture of the signal light and fluorescent light.