The maximum brightness of the LCD monitor, usually from cold cathode ray tube (backlight) to determine the brightness values are generally located in 200~250 CD/m2. Technology can achieve high brightness, but this does not mean that the brightness value, the higher the better, because of too high brightness display has the potential to make the viewers eye injuries. Between the LCD is a kind of solid and liquid substances, is not of itself luminous, needed extra light to just go. Therefore, the lamp number related to the brightness of the LCD monitor. First LCD display only upper and lower lamp, developed up to now, popularized the minimum four-light, high-end six lights. Placed four-tube design is divided into three forms: the four sides of a lamp, but the disadvantage is that shadow will appear in the Middle, solutions from top to bottom arrangement of four lamps, the last one is "u" type of place is actually two lights disguised two-lamp. Six tube design of practical use are three-lamp manufacturers three-lamp is bent into a "u" shape, and placed parallel in order to achieve the effect of six tubes.