Light source module

A light source module comprising:

• a light guide plate having a first surface, a second surface opposite to the first surface, a light incident surface connecting the first surface and the second surface, and a plurality of optical microstructures;
• at least one light emitting element located adjacent to the light incident surface;
• a reflector adhered to the second surface of the light guide plate through an adhesive gel;
• and
• a plurality of spacer units arranged between the light guide plate and the reflector, such that a distance is between the light guide plate and the reflector, sizes of the spacer units being greater than or equal to 1 micrometer, wherein the adhesive gel comprises a first adhesive gel and a second adhesive gel, the first adhesive gel is located between the spacer units and the light guide plate, and the second adhesive gel is located between the spacer units and the reflector, wherein viscosity of the first adhesive gel is greater than viscosity of the second adhesive gel.