Applying Lead-Free Fluorescent Lamp XEFL® to Backlights

― For Large-Screen Liquid Crystal Display Monitors ―

Ushio Inc. is pleased to announce that the Company has decided to enhance the luminance efficiency and service life of XEFL®, a lead-free fluorescent lamp developed for shops and signboards, and to launch the large-screen liquid crystal display monitor equipped with XEFL® used as the backlight. Details are as follows.

Since the start of test sales in December 2007, XEFL® has been used at shops and outdoor signboards, for its advantages such as non-emission of ultraviolet rays, long service life and durability to withstand influences of ambient temperatures.

Demands on large monitors have risen in recent years, for application to commercial advertisement media or so-called digital signage. Liquid crystal panel manufacturers have shown interest as it could generate a new application for large-sized panels. However, CCFL that contains lead has been used as a backlight for existing liquid crystal panels. As such, colors would become uneven when the monitor was positioned vertically, because the lead inside the lamps tended to aggregate at the lower portion. For this reason, numerous short lamps had to be placed horizontally when manufacturing liquid crystal monitors that are positioned vertically.

Since XEFL® uses xenon gas, it can be lit even when the lamp is positioned vertically. As such, the orientation of monitors can be changed freely, either vertically or horizontally.

Moreover, it is not susceptible to ambient temperatures because no lead has been used. For this reason, sufficient light intensity can be obtained with the backlight even with the liquid crystal advertisement monitors placed in semi-outdoor locations in cold regions.

The external electrode structure, another of the features of XEFL®, enables lighting at double the electric current of cold cathode fluorescent lamps (CCFL). This halves the number of lamps inside the liquid crystal monitor, enabling a reduction of up to about 30% in the manufacturing costs including those for peripheral members.

XEFL® for backlight has 10% better luminance efficiency and 50% longer service life compared to the existing XEFL® for lighting. Products up to approximately 1.5m in length can be manufactured. When used along the shorter sides of liquid crystal panels, the product can be applied with liquid crystal panels of up to about 120 inches.