Light modulation unit and display device thereof

A display device, comprising:

• a light modulation unit, comprising:
• an optical film, having a light exit surface and a light entrance surface opposite to the light exit surface, wherein the light exit surface forms a plurality of microstructures, each of the microstructures has a boundary connected to a boundary of a microstructure adjacent thereto, an orthographic projection of the boundary of the microstructure on the light exit surface is polygonal, the microstructures each have a height h in a normal direction of the light exit surface, the microstructures each also have a virtual aperture φ in an x-coordinate axis direction parallel to the light exit surface, and a ratio (h/φ) of the height h to the virtual aperture φ is 0.2 to 1;
• and
• a collimating optical layer, arranged opposite to the light entrance surface of the optical film;
• a display panel, opposite to the light exit surface of the optical film;
• and
• a first light emitting unit, arranged opposite to the collimating optical layer of the light modulation unit, and the light modulation unit being located between the display panel and the first light emitting unit;
• wherein
• the first light emitting unit emits an initial light beam to the collimating optical layer, the initial light beam passes through the collimating optical layer to form a collimated beam, the collimated beam passes through the light entrance surface to enter the optical film and then exits from the microstructures of the light exit surface to form a divergent light beam, and the divergent light beam has a divergence angle relative to a normal of the light entrance surface.