A visual optical lens

Abstract

This invention belongs to the field of optical lens technology, specifically relating to a visual optical lens, comprising: a first lens with positive optical power, the first lens having a first spherical surface and a second spherical surface, the first spherical surface being convex and the second spherical surface being convex; a second lens with positive optical power, the second lens having a third spherical surface and a fourth spherical surface, the third spherical surface and the fourth spherical surface being convex; a third lens with negative optical power, the third lens having a fifth spherical surface and a sixth spherical surface, the fifth spherical surface and the sixth spherical surface being concave; a fourth lens with positive optical power, the fourth lens having a seventh spherical surface and an eighth spherical surface, the seventh spherical surface and the eighth spherical surface being convex; the fourth spherical surface and the fifth spherical surface are combined to form a cemented lens; the visual optical lens of this invention can correct various aberrations, has a compact structure, good imaging effect, small size, large field of view, few lenses, high cost performance, and can achieve a wide range of diopter adjustment.

Description

Technical Field

[0001] This invention belongs to the field of optical lens technology, specifically relating to a visual optical lens, which is particularly suitable for the design of high-performance eyepieces for VR / AR headsets, night vision devices, and rifle microscopes. Background Technology

[0002] An eyepiece is a visual optical device used to observe the image formed by the optical system in front. It is a component of visual optical instruments such as telescopes and microscopes. Its main function is to magnify the real image obtained by the objective lens again. It is usually composed of several lenses.

[0003] Existing eyepieces typically have the following shortcomings:

[0004] ① The field of view is small and the distortion is large:

[0005] Most of the eyepieces used in transmission have a small field of view, which is compatible with a 0.39-inch screen with a diagonal of 10mm, but cannot be used with larger screens of 0.6-inch to 0.8-inch or larger. At the same time, the distortion is obvious and can be observed visually.

[0006] ② The issue of balancing resolution and cost:

[0007] 4K-level eyepieces (angular resolution > 60 PPD) typically require more than 6 lenses, which is too expensive.

[0008] To address this, we propose a visual optical lens to overcome the shortcomings of the existing technologies. Summary of the Invention

[0009] The purpose of this invention is to provide a visual optical lens to solve the problems existing in the prior art.

[0010] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0011] A visual optical lens, comprising, in sequence from the pupil to the screen:

[0012] A first lens with positive optical power has a first spherical surface and a second spherical surface on both sides of the first lens in the direction from the pupil to the screen, the first spherical surface being convex and the second spherical surface being convex.

[0013] A second lens with positive optical power, wherein the second lens has a third spherical surface and a fourth spherical surface on both sides in the direction from the pupil to the screen, and both the third spherical surface and the fourth spherical surface are convex surfaces;

[0014] A third lens with negative optical power, wherein the third lens has a fifth spherical surface and a sixth spherical surface on both sides from the pupil to the screen, and both the fifth spherical surface and the sixth spherical surface are concave.

[0015] A fourth lens with positive optical power, wherein the fourth lens has a seventh spherical surface and an eighth spherical surface on both sides from the pupil to the screen, and both the seventh spherical surface and the eighth spherical surface are convex surfaces;

[0016] The fourth and fifth spherical surfaces are combined to form a cemented lens.

[0017] As a further limitation of the technical solution of the present invention, the distance d between the pupil and the center point of the first lens satisfies the following condition: d > 12 mm.

[0018] As a further limitation of the technical solution of the present invention, the combined focal length EFL of the visual optical lens satisfies the following condition: EFL = 27.5mm.

[0019] As a further limitation of the technical solution of the present invention, the total diopter adjustment range q of the visual optical lens satisfies: ±4 < q < ±6.

[0020] As a further limitation of the technical solution of the present invention, the first lens, the second lens, the third lens and the fourth lens all satisfy the following condition: 1.45 < n < 1.8; where n represents the refractive index of the glass.

[0021] As a further limitation of the technical solution of the present invention, the first lens, the second lens, the third lens and the fourth lens all satisfy the following condition: 25 < λ < 60; where λ represents the Abbe number of the glass.

[0022] Compared with the prior art, the visual optical lens provided by the present invention can correct various aberrations, has a compact structure, good imaging effect, small size, large field of view, fewer lenses, high cost performance, and can achieve a wide range of diopter adjustment. Attached Figure Description

[0023] The present invention can be further illustrated by the non-limiting embodiments given in the accompanying drawings.

[0024] Figure 1 This is a schematic diagram of the structure of the visual optical lens of the present invention;

[0025] Figure 2 A parameter chart for the visual optical lens of the present invention;

[0026] Figure 3 This is an on-axis chromatic aberration diagram of the visual optical lens of the present invention;

[0027] Figure 4 This is a distortion curve diagram of the visual optical lens of the present invention;

[0028] Figure 5 This is a magnification chromatic aberration curve of the visual optical lens of the present invention;

[0029] Figure 6 This is an MTF curve diagram of the visual optical lens of the present invention;

[0030] The symbols for the main components are explained below:

[0031] First lens 1, first spherical surface 11, second spherical surface 12;

[0032] Second lens 2, third spherical surface 21, fourth spherical surface 22;

[0033] Third lens 3, fifth spherical surface 31, sixth spherical surface 32;

[0034] Fourth lens 4, seventh spherical surface 41, eighth spherical surface 42. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0036] Example:

[0037] The structure of this visual optical lens includes the pupil and the screen, as shown below. Figure 1 As shown:

[0038] The visual optical lens, from the pupil to the screen, includes, in sequence:

[0039] A first lens 1 with positive optical power has a first spherical surface 11 and a second spherical surface 12 on both sides from the pupil to the screen. The first spherical surface 11 is convex and the second spherical surface 12 is convex.

[0040] The second lens 2 has positive optical power. The second lens 2 has a third spherical surface 21 and a fourth spherical surface 22 on both sides from the pupil to the screen. Both the third spherical surface 21 and the fourth spherical surface 22 are convex surfaces.

[0041] The third lens 3 has negative optical power. The third lens 3 has a fifth spherical surface 31 and a sixth spherical surface 32 on both sides from the pupil to the screen. Both the fifth spherical surface 31 and the sixth spherical surface 32 are concave.

[0042] The fourth spherical surface 22 and the fifth spherical surface 31 are combined to form a cemented lens.

[0043] The fourth lens 4 has positive optical power. The fourth lens 4 has a seventh spherical surface 41 and an eighth spherical surface 42 on both sides from the pupil to the screen. Both the seventh spherical surface 41 and the eighth spherical surface 42 are convex surfaces.

[0044] When the visual optical lens is close to the screen, it is adjusted towards the near-vision end (negative diopter); when the lens is far from the screen, it is adjusted towards the far-vision end (positive diopter).

[0045] The visual optical lens provided by this invention satisfies the following conditions:

[0046] ① The distance d between the pupil and the center point of the first lens 1 is greater than 12mm, which can be used for situations where glasses are worn without being removed;

[0047] ② The combined focal length of the visual optical lens is EFL = 27.5mm, which can meet the 9.1x magnification of the optical lens;

[0048] ③The total diopter adjustment range q of the visual optical lens is: ±4 < q < ±6.

[0049] Meanwhile, the material requirements for each lens of this visual optical lens—first lens 1, second lens 2, third lens 3, and fourth lens 4—are as follows:

[0050] 1.45 < n < 1.8, where n represents the refractive index of the glass;

[0051] 25 < λ < 60, where λ represents the Abbe number of the glass;

[0052] Specifically, the specific parameters of each lens in this visual optical lens are as follows: Figure 2 The chart shown.

[0053] The following are the performance indicators of this visual optical lens, and the test results are as follows: Figures 3 to 6 As shown:

[0054] 1. The test was conducted using actual lighting conditions;

[0055] 2. The wavelength of the light is from 0.486μm to 0.656μm, where the green curve represents a wavelength of 0.588μm, the blue curve represents 0.656μm, and the red curve represents 0.486μm;

[0056] Please see Figure 3 , Figure 3 This is an axial chromatic aberration diagram of a visual optical lens, reflecting the degree to which different wavelengths deviate from the ideal image plane position in different pupil bands. The horizontal axis represents the offset, and the vertical axis represents the normalized pupil band, mainly based on the minimum offset of all wavelengths near the 0.707 pupil band. As can be seen from the figure, the horizontal distance between the wavelengths 486nm and 656nm, which are farthest apart in the 0.707 pupil band, is approximately 0.03mm.

[0057] Please see Figure 4 , Figure 4 This is a distortion curve graph for visual optical lenses, reflecting the difference between the actual image height and the ideal image height. The horizontal axis represents the percentage of distortion, and the vertical axis represents the half-image height. Figure 3As can be seen, the three wavelengths of light basically overlap, and the distortion of this visual optical lens is within 2.3%. When the human eye looks at the screen image through this lens, there will be no distortion or warping.

[0058] Please see Figure 5 , Figure 5 This is a chromatic aberration curve for visual optical lenses, where the horizontal axis represents the chromatic aberration shift, the vertical axis represents the half-image height, and the Airy curve represents the optical diffraction limit as a reference standard for the chromatic aberration curve. Figure 5 As can be seen, the maximum chromatic aberration of this visual optical lens is around 6.3 micrometers.

[0059] Please see Figure 6 , Figure 6 This is an MTF curve of a visual optical lens, reflecting the sharpness of the lens performance index; the horizontal axis is the number of line pairs, the vertical axis is the line pair MTF value, different colored lines represent different fields of view, the S line represents the sagittal plane, the T line represents the meridional plane, and the set values ​​correspond to different fields of view, the field of view is set to half image height.

[0060] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A visual optical objective, characterized in that: The visual optical lens is composed of four lenses in sequence from the eye pupil to the screen, specifically: a first lens with positive focal power, the first lens has a first spherical surface and a second spherical surface on both sides of the direction from the eye pupil to the screen, the first spherical surface is a convex surface, and the second spherical surface is a convex surface; a second lens with positive focal power, the second lens has a third spherical surface and a fourth spherical surface on both sides of the direction from the eye pupil to the screen, and the third spherical surface and the fourth spherical surface are both convex surfaces; a third lens with negative focal power, the third lens has a fifth spherical surface and a sixth spherical surface on both sides of the direction from the eye pupil to the screen, and the fifth spherical surface and the sixth spherical surface are both concave surfaces; a fourth lens with positive focal power, the fourth lens has a seventh spherical surface and an eighth spherical surface on both sides of the direction from the eye pupil to the screen, and the seventh spherical surface and the eighth spherical surface are both convex surfaces; the fourth spherical surface and the fifth spherical surface are combined into a cemented lens; the distance d between the eye pupil and the center point of the first lens satisfies the following condition: d>12mm; the combined focal length EFL of the visual optical lens satisfies the following condition: EFL=27.5mm; the parameter table of the visual optical lens is as follows: 。 2. A visual optical lens according to claim 1, characterized in that: the total diopter adjustment range q of the visual optical lens satisfies: ±4＜q＜±6。

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