Light Emitting Module and Optical Lens Thereof

A light emitting module, comprising:

• a substrate;
• a light source disposed on the substrate;
• and
• an optical lens, comprising:
• a body comprising a light-incident surface and a light-emitting surface, the light-emitting surface being located at an outer surface of the body, the light-incident surface being located at a bottom surface of the body, the body comprising a concave portion located at the center of the bottom surface, the concave portion being dented from the bottom surface to the light-emitting surface for accommodating a light source, and the surface of the concave portion being the light-incident surface;
• wherein the light-emitting surface comprises:
• a dented center light-emitting zone located at a center zone of the outer surface of the body, the dented center light-emitting zone being aligned with the center of the bottom surface of the body and being indented in a direction toward the light-incident surface, wherein a thickness (d1) of the body between the dented center light-emitting zone and the light-incident surface gradually increases outward from the center of the dented center light-emitting zone;
• and
• an arc-shaped peripheral light-emitting zone extended between the dented center light-emitting zone and the bottom portion of the body, wherein the shape of the outer-rim of the arc-shaped peripheral light-emitting zone is a square with four arc angles, so that after a light emitted from a light-emitting diode passes through the body, the light is formed into a square projection light
• wherein the optical lens is fixed to the substrate by the bottom portion of the body, and the light source is accommodated within the concave portion of the bottom surface of the body.