Conditions Of Operation And Structure Of The Led Backlight
Jun 07, 2022
A. LED light source
In recent years, LEDs have been successfully developed as cyan light sources, which are used to form white light sources after the reflection of light guide plates.
B. Light guide plate
C. Diffusers and prismatic lenses
Diffusers: they correct the angle of light and cover the optical structure of a total reflective surface, the optical tragedy of the diffuser includes the transmittance and the degree of haze, depending on the appearance of the light guide plate.
Prismatic lenses: Prismatic lenses are an important element to increase the frontal luminosity, the most effective and commonly used are the BEF series. 12 BEFII 90/50 can increase the luminosity of a light guide by approximately 1.41.8 times, and one DBEF can increase the luminosity of a light guide by up to 1.5 times.
D. Lamp Reflector
Function: To enclose the light emitted by the lamp and feed it as far as possible into the light guide.
The shape of the reflector has a considerable influence on the light guide's light input efficiency.
Small and medium size reflectors are often made of a soft material consisting of a silver plating and PET, which has an approximate efficiency of 80%.
Larger sizes are often made of a special and fixed copper material to increase the efficiency of the reflector, which can reach over 90%.
When designing the mechanism, attention must be paid to the phenomenon of current leakage.
E. External frame assembly
External frame assembly: fixing the whole backlight module to prevent damage and influence on the function by improper collision and sweat.
F.Reflector
Reflector plate: reflect the light source that has not been scattered into the light conduction area again, its own light source also has a slight scattering effect.
G. Polarisation
The light emitted from the light guide consists of two polarisation directions: P-polarised and S-polarised.
P-polarised light passes through the LCD, but S-polarised light does not, resulting in nearly half of the light source not being used.
The polarisation technology uses a multilayer structure to split the light into P-polarised and S-polarised light, which is reflected and converted into P-polarised light to pass through the LCD.
The polarisation technology increases the brightness of the LCD and reduces the number of prism lenses used and the power consumption.
H. Inverter
The Inverter is the provider of the high voltage pulses that drive the lighting of the lamp.
It converts the DC voltage signal from the Power Supply into a high-frequency high-voltage pulse, which enables the lamp to be lit continuously.
