Method for solving brightness balance of light source of display module based on grating lens

The invention relates to a method for solving brightness balance of a light source of a display module based on a grating lens. The display module comprises R, G and B monochromatic LED lamps, a grating lens and a light valve array; each light valve comprises three sub-light valves which are arranged in parallel and can be independently controlled, and the three sub-light valves correspond to three colors of R, G and B; two LED single lamps with the same color form a group, and interference diffraction fringes corresponding to the two LED single lamps are superposed to form fringes with uniform brightness after passing through the grating lens. According to the invention, light emitted by an LED forms bright fringes through interference by using a specific grating, and the bright fringes are projected to sub light valves of the same color in a light valve array; one monochromatic LED in each group forms interference through the grating lens, the wave crest/wave trough position of the diffraction fringes and t