BACKLIGHT DRIVING CONTROL DEVICE AND ITS DRIVING CONTROL METHOD OF LIQUID CRYSTAL DISPLAY ELEMENTS

摘要

A backlight luminescence control device for use in a portable computer to control a backlight of a liquid crystal display. When an AC adaptor is not connected to the portable computer, the device senses the voltage level of a DC battery and generates an electrical signal that indicates the status of the battery. From the voltage level of the DC battery, the device ascertains the appropriate luminescence level of a cold-cathode fluorescent backlight lamp (CCFL), automatically controls the brightness of the CCFL through several levels of luminosity, and optimizes the luminescence of the CCFL according to the voltage level available in the DC battery.