Display module, and display device

A display device, comprising a display module, wherein the display module comprises a first substrate and a second substrate, both of which are cell-assembled with each other, and a first electrode, a liquid crystal layer, and a second electrode arranged between the first substrate and the second substrate in that order, wherein:

• the display module further comprises a plurality of gratings distributed in an array on a surface of the first electrode on a side thereof facing the liquid crystal layer, and drive electrodes arranged respectively on sides of respective gratings facing away from the first electrode;
• the liquid crystal layer comprises only positive liquid crystal molecules;
• both a refractive index of the first electrode and a refractive index of the first substrate are greater than a normal refractive index no of liquid crystal in the liquid crystal layer;
• and
• a refractive index of each of the plurality of gratings lies between the normal refractive index no and an abnormal refractive index ne of the liquid crystal.