A 20mm-in-diameter-CRT-lighting-element was developed for the application of outdoor sighnboards, which displayed characters and symbols in some fixed areas of giant display boards. The device performed high average luminance of 20,000〜30,000cd/m^2 in 17mm in diam. with low power consumption of 0.92W. The construction, material, and manufacturing process were studied, so that both high reliability and cost reduction were performed by appliing technologies of pre-formed lenticular panel and printing phosphor layer, high resistive and low-cost materials, and special seal process with frit. The device can be operated even in the outdoor environment of -40〜+60℃, 100%RH.
