Optical device and light source module including the same

An optical device comprising:

• a first surface facing a light source, the first surface defining a concave recess portion in a central portion of the first surface;
• a second surface disposed opposite the first surface, the second surface being configured to reflect light which is incident on the concave recess portion;
• and
• a side surface connecting the first surface and the second surface to each other,
• wherein the second surface includes a first reflective portion having a concave surface curving toward the first surface, and a second reflective portion having a substantially flat region, the second reflective portion being interposed between a first reflective portion edge of the first reflective portion and an outer second surface edge of the second surface, and
• wherein the first reflective portion is configured to totally reflect light which is incident at a predetermined angle or more once to the side surface, the predetermined angle being within a range of 20 degrees to 40 degrees with respect to a top surface of the light source.

A light source module comprising:

• a substrate;
• at least one light source mounted on the substrate;
• and
• at least one optical device disposed on the at least one light source, the at least one optical device including a first surface defining a light incident surface, on which light of the at least one light source is incident, a second surface disposed opposite the first surface, the second surface being configured to reflect the light which is incident on the light incident surface to change an optical path, and a light exit surface defined by a side surface between the first surface and the second surface,
• wherein the second surface includes a first reflective portion having a concave surface curving toward the first surface, and a second reflective portion having a substantially flat region, the second reflective portion being interposed between a first reflective portion edge of the first reflective portion and an outer second surface edge of the second surface, and
• wherein the first reflective portion is configured to totally reflect light incident at a predetermined angle or more once to the light exit surface, the predetermined angle being within a range of 20 degrees to 40 degrees with respect to a top surface of the at least one light source.