Optical system and display apparatus

An optical system, comprising:

• a lens component, comprising at least two lenses;
• the at least two lenses comprising a first surface, a second surface, a third surface and a fourth surface arranged sequentially along a direction of an optical axis of the lens component;
• and the second surface and the third surface having a same surface type parameter;
• a transflective film, located on a side of the first surface of the lens component away from the second surface of the lens component;
• a reflective polarization layer, located between the second surface and the third surface of the lens component;
• a phase retardation film, located on a side of the transflective film that faces the second surface;
• wherein light transmitted through the transflective film and then incident on the lens component is configured to be folded back between the transflective film and the reflective polarization layer, and exit from the reflective polarization layer;
• the third surface and the fourth surface are two surfaces of a same lens;
• the first surface is a convex surface, the second surface is a concave surface, the third surface is a convex surface, the fourth surface is a concave surface;
• an absolute value of a curvature radius of the first surface and an absolute value of a curvature radius of the second surface are both less than an absolute value of a curvature radius of the fourth surface;
• a ratio of the curvature radius of the first surface to the curvature radius of the second surface is 0.5 to 1.25;
• and an absolute value ratio of a conic constant of the first surface to a conic constant of the second surface is no greater than 0.4.