Reflective eyepiece optical system and head-mounted near-to-eye display device

A reflective eyepiece optical system, composed of a first lens group, and a first optical element and a second lens group for transmitting and reflecting a light from a miniature image displayer;

• wherein the second lens group comprises an optical reflection surface, and the optical reflection surface is an optical surface farthest from a human eye viewing side in the second lens group;
• the optical reflection surface is concave to the human eye;
• the first optical element reflects the light refracted by the first lens group to the second lens group, and then transmits the light refracted, reflected, and refracted by the second lens group to the human eye;
• an effective focal length of the eyepiece optical system is fw, an effective focal length of the first lens group is f1, an effective focal length of the second lens group is f2, and fw, f1, f2 satisfy the following relations (1) and (2):
• f1/fw<−0.47 (1);
• −2.53<f2/fww<−0.64 (2);
• the first lens group comprises a first sub-lens group, a second sub-lens group, a third sub-lens group, and a fourth sub-lens group arranged coaxially and successively along an optical axis from the human eye viewing side to the miniature image displayer side;
• an effective focal length of the first sub-lens group is f11, and f11 is a positive value;
• an effective focal length of the second sub-lens group is f12, and f12 is a negative value;
• an effective focal length of the third sub-lens group is f13, and f13 is a positive value, and f11, f12, f13, and f1 satisfy the following relations (3), (4), and (5):
• 0.19<f11/f1 (3);
• f12/f1<−0.019 (4);
• 0.019<f13/f1 (5).