Backlight module

A backlight module, which comprises:

• a light-guiding plate, a blue light source disposed on one side of the light-guiding plate, and a red light conversion layer and a green light conversion layer stacked and disposed above the light-exiting side of the light-guiding plate;
• the red light conversion layer comprising a red quantum dot (QD) film;
• the green light conversion layer comprising a green QD film, and two metal wire grids disposed respectively on both sides of the green QD film;
• the metal wire grid comprising a dielectric layer and a plurality of metal wire grid units disposed on the dielectric layer and sequentially arranged;
• the metal wire grid unit comprising a metal strip and a strip-shaped space disposed on one side of the metal strip;
• the metal wire grid units of the two metal wire grids disposed on both sides of the green QD film being arranged in the same direction;
• the distance between the two metal wire grids disposed on both sides of the green QD film being a multiple of a specific green light wavelength, the specific green light wavelength being an arbitrary wavelength within a green light band emitted by the green QD film;
• wherein P state is defined as the polarization direction perpendicular to the arrangement direction of the metal wire grid units, and S state is defined as the polarization direction parallel with the arrangement direction of the metal wire grid units;
• for S state, the metal wire grid only reflects the green light band emitted by the green QD film, and while for P state, the metal wire grid only lets the green light band emitted by the green QD film pass;
• wherein the green light band emitted by the green QD film being 500-600 nm, and the specific green light wavelength being an arbitrary wavelength within 500-600 nm;
• wherein the metal wire grid being disposed with the side disposed with dielectric layer or the side disposed with the plurality of metal wire grid units facing towards the green QD film;
• wherein in the metal wire grid unit, the metal strip and the strip-shaped space being both straight and parallel to each other.