Optical system and display device

An optical system, comprising:

• an optic group, comprising a first optic and a second optic which are arranged one on top of the other;
• a polarizing transflective film, arranged at a side of the first optic away from the second optic;
• a phase retardation film, arranged between the polarizing transflective film and the first optic;
• a transflective film, arranged at a side of the second optic away from the first optic,
• wherein the first optic comprises a plane surface and a first aspheric surface, and the second optic comprises a second aspheric surface and a third aspheric surface, the second aspheric surface is located at a side of the first aspheric surface away from the plane surface, and the third aspheric surface is located at a side of the second aspheric surface away from the first optic;
• both of the first aspheric surface and the third aspheric surface are convex surfaces, the second aspheric surface is a concave surface, and a side of the plane surface away from the first aspheric surface is a light exiting side of the optic group;
• and
• a focal length of the optical system is 26 mm to 30 mm, an effective aperture of the optic group is 55 μm to 58 μm, a curvature radius of the first aspheric surface is −120 mm to −140 mm, a curvature radius of the second aspheric surface is −175 mm to −185 mm, and a curvature radius of the third aspheric surface is −100 mm to −110 mm.