LCD LED Backlight Board Can Be Divided Into Several Categories?
Feb 22, 2023
The backlight panel is an optical component that provides the backlight source in LCD products. Since the LCD glass itself does not have light-emitting characteristics, a light-emitting source will be added behind the LCD glass as needed, i.e., a backlight panel. Applications cover medical, beauty, instrumentation, automotive equipment, industrial equipment, banking terminals, office automation, communications, electronic toys, consumer products.
1, LCD LED backlight board working principle LED backlight board working principle is the point light source (LED) into a surface light source (backlight board, backlight)
2, LCD LED backlight panel classification. Backlight panel is currently divided into EL, CCFL, LED according to the type of light source, according to the location of the light source distribution is divided into side light type and straight down type (bottom backlight type).
The following is a brief introduction to them - Side Light Type: Backlight panels made by setting a line or point light source on the side of a specially designed light guide. According to the actual use of the needs, can be made into bilateral or even trilateral type. General edge backlight can be made very thin but the light source light utilization rate is very small, the thinner the utilization rate is smaller, about 50%. The core of the technology is the design and manufacture of the light guide plate. Edge light type commonly used in LED backlight and CCFL backlight
LED light backlight: LED lights are also called light-emitting diodes. Compared with other light sources, the power consumption of a single LED lamp is very small. From blue to red LED lights are available in many colors, a special color is white, commonly used chromaticity range is shown in Table 3. in a variety of colors, can be broadly divided into two kinds of high brightness and low brightness: basically Table 1 is low brightness (although amber, orange and red are also slightly brighter).
Since white is a mixed color with no apparent wavelength value, it is represented by its coordinate value on the chromaticity chart. We customize them as "cool white" and "warm white". Various colors have the problem of chromatic aberration, in which blue and white are more obvious, especially white, now the led suppliers can not effectively control.
CCFL backlight: the advantage of this backlight is high brightness, so basically used for large area black and white negative phase, blue mode negative phase and color LCD devices. Theoretically, it can make various colors according to the color matching principle of the three primary colors. The disadvantage is high power consumption, inverter circuit driven, narrow operating temperature between 0-60 degrees, while other backlight panels such as LED can reach -20-70 degrees.
Bottom backlight type: is a flat surface light source with a certain structure, can be a continuous uniform surface light source, such as e1 or flat fluorescent lamps, it can also be composed of more point light sources, such as dot matrix LED or incandescent backlight panel. Commonly used are LED dot matrix and EL backlight.
EL backlight:Electroluminescence, a cold light source that emits light through the intrinsic luminescence of phosphors excited by an alternating electric field. Its advantage is thin, can be 0.2 ~ 0.6 mm thick. The disadvantages are low brightness, short service life (generally 3000~5000 hours), inverter drive, circuit interference, flicker and noise generation. Electroluminescence is driven by inverter and driver IC. Currently, the frequency and load output voltage of the driver IC cannot meet the typical conditions of electroluminescence (400 Hz, 100 V AC), so the brightness is lower than that driven by the inverter. White light (full color) EL and LCD backlight panels have appeared one after another. However, due to their dark brightness, they are basically used for small size LCDs below 4 inches. For example, cell phones, handheld computers, game consoles, etc. Full-color (white), large size brightness backlight panel, now the mainstream or use CCFL as the light source LED bottom backlight: its advantage is good brightness, good uniformity. The disadvantage is that the thickness is larger (more than 4.0mm), the use of a larger number of led, the heat phenomenon is obvious. Generally use low bright color for design, high bright color due to high cost is basically ignored.
