Optical system and virtual reality device

1 . An optical system, comprising a display unit and a first lens sequentially along a light transmission direction,

wherein the first lens is provided at a light emitting side of the display unit, the first lens comprises a first surface close to the display unit and a second surface away from the display unit, and the second surface has a planar structure,

wherein an optical splitter is provided between the first surface and the display unit,

wherein a first phase retarder and a polarization reflector are provided at a side of the first lens away from the display unit, and the first phase retarder is provided between the first lens and the polarization reflector,

wherein light emitted from the display unit is split into a reflected first beam and a transmitted second beam by the optical splitter,

wherein the second beam sequentially passes through the first lens and the first phase retarder and is reflected by the first polarization reflector,

wherein the second beam reflected by the first polarization reflector sequentially passes through the first phase retarder and the first lens, and is split into a reflected second-first beam and a transmitted second-second beam by the optical splitter, and

wherein the second-first beam sequentially passes through the first lens, the first phase retarder and the first polarization reflector to arrive at eyes of a user.

2 . The optical system according to claim 1 , wherein the optical system further comprises a movable component connected with the display unit to adjust a distance between the display unit and the first lens.

3 . The optical system according to claim 1 , wherein the optical system satisfies following relationships: 50<ABS(R1)<100, ABS(Conic1)<5,

wherein R1 is a curvature radius of the first surface, and ABS(R1) is an absolute value of R1, and

wherein Conic1 is a conic coefficient of the first surface, and ABS(Conic1) is an absolute value of Conic1.

4 . The optical system according to claim 1 , wherein the optical system satisfies a following relationship: 5<T1<10, and

wherein T1 is a central thickness of the first lens along an optical axis.

5 . The optical system according to claim 1 , wherein the optical system satisfies a following relationship: 10<T2≤16, and

wherein T2 is a distance from the first surface to the display unit.

6 . The optical system according to claim 1 , wherein the optical system satisfies a following relationship: 3<L1<5, and

wherein L1 is an edge thickness of the first lens.

7 . The optical system according to claim 1 , wherein the optical system satisfies a following relationship: f=6.3*f1, and

wherein f is a focal length of the optical system, and f1 is a focal length of the first lens.

8 . The optical system according to claim 1 , wherein the optical system further comprises a second lens provided at a light exiting side of the first lens, and

wherein the second lens is any one of a plano-convex lens, a plano-concave lens and a meniscus lens.

9 . The optical system according to claim 1 , wherein the optical system further comprises a polarizer provided at a side of the polarization reflector away from the phase retarder.

10 . A virtual reality device, comprising:

a housing; and

and the optical system according to claim 1 ,

wherein the optical system is accommodated in the housing.