Internal patterning of the glass backlight module for LCD panel by laser

Backlight module is an essential part of Liquid Crystal Display panel. Its function is to deflect and scatter the light from LED source so that the whole display can be illuminated homogeneously through the light guide plate. The commonly design is applying different patterns of V-cut grooves on the surfaces of thin polymer material plates. The process may be by etching or injection molding. The parts are then bonded together with the light source. In this study we designed a one-step alternative method on thin non-alkaline glasses. The light deflection-diffusion pattern was engraved inside the glass between both sides by a picosecond infrared laser. The spot size of the laser is small enough to create dot and line microstructures less than 20µm size. The laser cuts are in round or oval shape and the light deflection is in the manner of Lambertian scattering, which is different from the deflection-reflection V-cut designs. This method can simplify the manufacturing in one step and suitable for different materials. The luminance existence pattern was then examined with led light source by a spectroradiometer.