| 摘要 |
The present invention discloses a backlight including external electrode fluorescent lamps and a method for driving the backlight. The backlight includes fluorescent lamps having external electrodes made of an electrically conductive material for wrapping outer peripheral surfaces including edge cross-sections on both ends of a glass tube with a layer of fluorescent substance applied thereon. The backlight is constructed in a manner that a plurality of such fluorescent lamps are installed at outer portions of a plastic light guide; that an alternating current type power source is applied from the outside to the fluorescent lamps by installing a plurality of the fluorescent lamps between a reflecting plate and a diffusing plate and electrically connecting them with one another; or that the fluorescent lamps are installed at a predetermined interval between upper and lower substrates with a layer of fluorescent substance applied thereon and spaced from each other, and electrodes to which an alternating current type power source is applied from outside are formed on opposite outer or inner faces of the assembled upper and lower substrates. According to the present invention, since the electrodes of the fluorescent lamps are formed at external portions and are repeatedly disposed, the fluorescent lamps can be interconnected in parallel to and driven by a single power source. Further, since the fluorescent lamps serve as a partition and simultaneously emit light by themselves, their uniform luminance can be maintained and thinner backlight can be obtained. The backlight of the present invention is driven by a square wave from a switching inverter, and is characterized by the use of an overshooting waveform and a self-discharge effect favorable to an initial discharge, thereby driving it by a low frequency of several dozen kHz and thus realizing high luminance and high efficiency. |
