| 摘要 |
PURPOSE:To make overall evaluation of the design possible including all the barrier materials which reduce the intensity of electron beams on the way of reaching the fluorescent material and emitting light and to form a dark color coating layer on the metal back in a maximum efficiency by making the dead voltage of the fluorescent screen as the design measure. CONSTITUTION:When the acceleration voltage of an electron beam is 20 to 30KV for such as the case of color cathode-ray tube, the dead voltage before forming a dark color coating layer, that is the threshold voltage (hereafter called D.V) when the voltage is reduced from a specified high voltage to a lower voltage at which the fluorescent screen stops the emission of light, is made 6KV or less and the increase in D.V due to forming a dark color coating layer is within 3.5KV and the final total D.V is 6KV or less. The achievement thus obtained is a great improvement of efficiency of about 86% comparing with conventional examples having a D.V of 6KV at the formation of the metal back and a D.V of 8.5KV for the completed tube. |
