Katsumi Terada

A High-Intensity Flat Vacuum Fluorescent Lamp.

A high-intensity flat vacuum fluorescent lamp utilizing cathode-luminescence has been developed for LCD backlighting. The apparatus used was a glass vessel consisting of two concave-shaped pieces of glass with two mesh-shaped grid electrodes and the line cathodes fixed at the solder glass fritting seal section between the front and rear pieces of glass. The lamp consists of tetrode. The glass vessel is made of Barium-Strontium glass, so that a high voltage can be applied to the anode and so that a high luminous efficiency can be obtained. As we adopt an interference filter and a liquid-cooling system to add high power to the phosphor layer, this lamp can produce an intensity of 70, 000 cd/m2 (Green). Moreover, excellent results concerning brightness uniformity, brightness control and temrperature stability are also obtained.This lamp is expected to be used for LCD backlighting of LC projectors and for head-up displays of cars and planes.