Disclosure of Invention
The invention provides a VR lens, which consists of a first lens L1, a second lens L2 and a third lens L3; s1 is a display screen, S2 and S3 are respectively the front and back surfaces of the first lens L1, S4 and S5 are respectively the front and back surfaces of the second lens L2, and S5 and S6 are respectively the front and back surfaces of the third lens L3. Wherein S1 is a plane, S5 is a sphere, and S2, S3, S4 and S6 are aspheric. The focal length of the lens is 45mm, the maximum object plane height on the display screen S1 is 25mm, the corresponding angle of vision of human eyes is 70 degrees, and the design wavelength of the lens is 400 nm-700 nm.
The technical scheme of the invention is as follows: a VR lens.
The lens parameters of the invention include:
the curvature radius of the front surface S2 of the first lens L1 is-100 mm to-50 mm, the conical coefficient k is 1 < k < 5, the second-order coefficient alpha 2 is less than 0, the fourth-order coefficient alpha 4 is more than 0, and the sixth-order coefficient alpha 6 is more than 0; the curvature radius of the back surface S3 of the first lens L1 is-50 mm to-10 mm, the conical coefficient k satisfies-10 < k < -1, the second-order coefficient alpha 2 < 0, the fourth-order coefficient alpha 4 > 0 and the sixth-order coefficient alpha 6 > 0; the curvature radius of the front surface S4 of the second lens L2 is-50 mm to-10 mm, the conical coefficient k satisfies-10 < k < -1, the second-order coefficient alpha 2 is more than 0, the fourth-order coefficient alpha 4 is less than 0, and the sixth-order coefficient alpha 6 is less than 0; the curvature radius of the rear surface S5 of the second lens L2 is 10 mm-50 mm; the curvature radius of the rear surface S6 of the third lens L3 is-100 mm to-50 mm, the conical coefficient k satisfies 5 < k < 15, the second-order coefficient alpha 2 < 0, the fourth-order coefficient alpha 4 < 0 and the sixth-order coefficient alpha 6 > 0.
The distance between the display screen S1 and the front surface S2 of the first lens L1 is 10 mm-30 mm; the thickness of the first lens L1 is 10 mm-20 mm; the rear surface S3 of the first lens L1 is 2 mm-10 mm away from the front surface S4 of the second lens L2; the thickness of the second lens L2 is 2 mm-5 mm; the rear surface of the second lens coincides with the front surface of the third lens L3 and is S5; the rear surface S6 of the third lens L3 is spaced from the front surface S7 of the cornea of the human eye by 10mm to 30mm.
The maximum diameter of the display screen S1 is 50mm; the diameter of the first lens L1 is 40 mm-60 mm; the diameter of the second lens L2 is 30 mm-50 mm; the diameter of the third lens L3 is 30 mm-50 mm.
The invention has the beneficial effects that:
1. the VR lens has a focal length of 45mm, a design wavelength of 400-700 nm, a corresponding human eye field angle of 70 degrees and a maximum object plane height of 25mm.
2. The optical lens is composed of three lenses only, and has a simple structure.
Detailed Description
The invention will be further described with reference to the accompanying drawings and examples of implementation.
An embodiment of the present invention is shown in fig. 1: S7-S13 are human eye models, and the corresponding optical parameters are shown in Table 1. Wherein: l4 is cornea, L5 and L6 are anterior chamber, L7 is crystalline lens, L8 is vitreous; s7 and S8 are anterior and posterior surfaces of the cornea, respectively, S10 is the pupil, S11 and S12 are anterior and posterior surfaces of the lens, respectively, and S13 is the retina. In the model, the human eye is approximately a sphere with an inner diameter of 22mm, the diameter of the pupil of the human eye is 2-4 mm, and the diameter of the pupil S10 is 4mm and is selected as a diaphragm of the whole optical system.
As shown in fig. 1: the VR lens consists of a first lens L1, a second lens L2 and a third lens L3; s1 is a display screen, S2 and S3 are respectively the front and back surfaces of the first lens L1, S4 and S5 are respectively the front and back surfaces of the second lens L2, and S5 and S6 are respectively the front and back surfaces of the third lens L3. Wherein S1 is a plane, S5 is a sphere, and S2, S3, S4 and S6 are aspheric. The aspherical surface satisfies the formula (1):
in the formula (1), z (R) is displacement of the aspheric surface in the z-axis direction, where the distance z-axis is R, relative to the vertex of the aspheric surface in the z-axis direction, R is the radius of curvature of the aspheric surface (R > 0 is convex, R < 0 is concave), k is the conic coefficient of the curved surface (k < -1 is hyperbola; k= -1 is parabolic; k > -1 is elliptical; k=0 is a circle), α2 is a second-order coefficient, α4 is a fourth-order coefficient, and α6 is a sixth-order coefficient.
The curvature radius of the front surface S2 of the first lens L1 is-100 mm to-50 mm, the conical coefficient k is 1 < k < 5, the second-order coefficient alpha 2 is less than 0, the fourth-order coefficient alpha 4 is more than 0, and the sixth-order coefficient alpha 6 is more than 0; the curvature radius of the back surface S3 of the first lens L1 is-50 mm to-10 mm, the conical coefficient k satisfies-10 < k < -1, the second-order coefficient alpha 2 < 0, the fourth-order coefficient alpha 4 > 0 and the sixth-order coefficient alpha 6 > 0; the curvature radius of the front surface S4 of the second lens L2 is-50 mm to-10 mm, the conical coefficient k satisfies-10 < k < -1, the second-order coefficient alpha 2 is more than 0, the fourth-order coefficient alpha 4 is less than 0, and the sixth-order coefficient alpha 6 is less than 0; the curvature radius of the rear surface S5 of the second lens L2 is 10 mm-50 mm; the curvature radius of the rear surface S6 of the third lens L3 is-100 mm to-50 mm, the conical coefficient k satisfies 5 < k < 15, the second-order coefficient alpha 2 < 0, the fourth-order coefficient alpha 4 < 0 and the sixth-order coefficient alpha 6 > 0.
The distance between the display screen S1 and the front surface S2 of the first lens L1 is 10 mm-30 mm; the thickness of the first lens L1 is 10 mm-20 mm; the rear surface S3 of the first lens L1 is 2 mm-10 mm away from the front surface S4 of the second lens L2; the thickness of the second lens L2 is 2 mm-5 mm; the rear surface of the second lens coincides with the front surface of the third lens L3 and is S5; the rear surface S6 of the third lens L3 is spaced from the front surface S7 of the cornea of the human eye by 10mm to 30mm.
The maximum diameter of the display screen S1 is 50mm; the diameter of the first lens L1 is 40 mm-60 mm; the diameter of the second lens L2 is 30 mm-50 mm; the diameter of the third lens L3 is 30 mm-50 mm.
The focal length of the lens is 45mm, the maximum object plane height on the display screen is 25mm, the corresponding angle of vision of human eyes is 70 degrees, and the design wavelength of the lens is 400 nm-700 nm.
In one embodiment, the optical path is shown in fig. 2, and the lens specific parameters are shown in table 1. The image quality point column diagram of the optical system of the human eye imaging corresponding to 0 mm-25 mm on the display screen S1 is shown in FIG. 3, wherein five wavelengths of 0.47 μm, 0.51 μm, 0.555 μm, 0.61 μm and 0.65 μm are selected, and the corresponding weights are respectively 0.091, 0.503, 1, 0.503 and 0.107. The simulation of the human eye imaging effect is shown in fig. 4.
In the present embodiment, the main optical indexes are as follows:
1. lens focal length f=45 mm;
2. angle of field of human eye: 70 ° (-35 °);
3. the maximum object plane height of the display screen is 25mm;
4. designing a wave band: 400 nm-700 nm.
TABLE 1
The present invention is not limited to the above-mentioned embodiments, but is not limited to the above-mentioned embodiments, and any simple modification, equivalent changes and modification made to the above-mentioned embodiments according to the technical matters of the present invention can be made by those skilled in the art without departing from the scope of the present invention.