. Various DC AC Inverter Unit for Liquid Crystal Display (LCD) Panel free download

File name DC AC Inverter Unit for Liquid Crystal Display (LCD) Panel.pdf

DC-AC INVERTER UNIT DC/ AC Inverter Unit for Liquid Crystal Display (LCD) Panel 1. Introduction Liquid crystal display (LCD) panels are used in various applications ranging from smaller portable electronic equipment to larger fixed location units. Applications such as the display device for laptop PCs, word processors, arcade game machines, pinball machines, video cameras, automobile navigation systems, and industrial machines. The LCD panel itself cannot emit light. Therefore, a backlight system that supplies the light from behind is normally required. The backlight system consists of a light emitting device that produces light, a conductor panel that distributes the light to the entire LCD surface uniformly, and a power supply that drives the light emitting device. Currently, the most commonly used light emitting device is a fluorescent tube called a cold cathode tube or CCFL. The CCFL is called a cold cathode tube because even though the principle of illumination is the same as that of the hot cathode tubes used by indoor lamps, this lamp does not require preheating of the filament. Also, the electrodes at the end of the bulb stay at a low temperature while emitting light. A special power supply, inverter, which generates approximately 1000 to 1500V AC is required to drive a CCFL. This inverter is a small power supply used to make this CCFL illuminate, and is one of the important functional parts of a complete LCD display. As LCD panels are used in various markets and applications, requirements for the backlight system have become diversified as shown in table 1. In particular, the European computer display market is evolving from CRT displays to the LCD displays, this is partly due to strict EMI emission regulations. DC/AC Inverter characteristic applied to various DC/AC Inverter characteristic Market Downsizing Efficiency Life Wide Dimming View Finder ooo ooo o Video Monitor oo ooo oo Audio & Visual LCD TV oo ooo oo LCD Monitor oo oo ooo oo Automotive Navigation oo oo ooo oo Note PC oo ooo ooo oo Computer PCS ooo ooo oo oo Communication Pager ooo oo