At present, CCFL, WLED and RGB LED LCD display is still three main backlight mode, we can buy LCD monitor before you know about these backlight knowledge, because the backlight devices are inside the display, ordinary consumers can not directly see, like WLED And RGB LED backlit display, businesses say that the LED screen, in fact, is the concept of stealing, the real LED screen should be like a large square on the billboard (as shown below) as the design, it can now miniaturization of the manufacturers around the world One, so in the liquid crystal display market, can only find it another law, OLED may be a good choice.
First, CCFL backlit screen advantages and disadvantages
CCFL full name Cold Cathode Fluorescent Lamp (cold cathode fluorescent tube), filled with inert gas (including some of the mercury vapor), the wall has a phosphor layer, looks like a fluorescent tube, the head a bit like a city of neon lights , Installed in the LCD display structure as shown below (Note: the actual location and orientation may be different, including the following LED placement location there are several design methods): before the CCFL, mostly using EEFL backlight technology backlight, CCFL backlight technology and the following WLED are now very mature technology, and RGB LED is still not too mature, precisely, the design requirements of a higher point, so many third-rate manufacturers is difficult to design a good quality RGB LED Backlight display.
CCFL Backlight Advantages:
Low cost, simple manufacturing process, mature technology.
CCFL Backlight Disadvantages:
Short life (aging fast), low luminous efficiency (power consumption), low brightness uniformity, low color purity, poor color performance, not environmentally friendly, bulky, high drive voltage, impatient impact (see the picture so big bulb Know certainly not impatient).
Second, WLED backlight advantages and disadvantages
WLED full name White Light Emitting Diode (white light diode), WLED CCFL backlight as an alternative way, the technology is not much improvement, the display backlight to use LED, will have a power (compared to CCFL reduced by about 20% Power), long life and impact resistance characteristics, backlight module structure as follows:
1, side WLED backlight: the side of the backlight need to use the light guide plate (glue) to the LED light evenly distributed to the display area, so the concept of light leakage from the resulting, when the light guide film (board) is not good or structural layer When the bond between the problems, the light will be very obvious.
2, the bottom WLED backlight:
The bottom of the uniform distribution of LED module is also a design, this approach looks like the first process than the first complex, the entire backlight board need to consider the welding and wiring problems, the edge of the view, when the device is too scattered, the stability Sex must have a negative impact. If the RGB LED will certainly be delayed response to the RGB LED.
WLED Backlight Advantages:
Drive voltage is low, long life, small size, light weight, good color performance, more uniform brightness, more environmentally friendly, impact resistance.
WLED Backlight Disadvantages:
Brightness and contrast relative (RGB LED) low.
Third, RGB LED backlit screen advantages and disadvantages
Although RGB LED looks very similar to WLED, but its design requirements are higher, RGB LED is still some high-end LCD display preferred backlight type, so expensive point is also a matter of course, RGB LED using three primary colors and produce white backlight, In the project, we have to take into account the voltage and current changes caused by the resulting color shift, but also need to take into account the RBG LED failure or partial failure after the impact of the problem, compared to WLED, the production cost is high and complex ( Cottage is not).
RGB LED Backlight Advantages:
Small size, light weight, higher efficiency, better lumen maintenance, better brightness and contrast.
RGB LED Backlight Disadvantages:
High cost of manufacturing, color dispersion, color offset and other phenomena, is the use of RGB LED can not avoid the problem, no matter how the development of technology, RGB blending out of white with WLED white will always be different. Another RGB LED backlight will encounter a response time.