WO2022141380A1 - Optical eyepiece system with large angle of view and head-mounted display device - Google Patents

Abstract

An optical eyepiece system with a large angle of view and a head-mounted display device. The optical eyepiece system comprises a first lens set (D1), a second lens set (D2) and a third lens set (D3) which are coaxially and sequentially arranged in a direction of an optical axis from a human eye observation side to a micro display (IMG) side, wherein the first lens set (D1) has a positive optical focal length, the second lens set (D2) has a negative optical focal length and the third lens set (D3) has a positive optical focal length; the first lens set (D1) consists of two optical lenses, that is, a first lens (L1) close to the human eye side and a second lens (L2) away from the human eye side; the first lens set (D1) comprises at least two Fresnel optical surfaces (2, 3); the first lens (L1) comprises at least one Fresnel optical surface; the second lens set (D2) comprises a third lens (L3) and a fourth lens (L4) which are adjacent to the first lens set (D1) and are sequentially arranged along an optical axis; the third lens (L3) and the fourth lens (L4) each are negative lenses; the third lens set (D3) consists of one optical lens; the third lens set (D3) comprises a fifth lens (L5); the fifth lens (L5) is a positive lens; and the optical eyepiece system has the advantages of large angle of view, high image quality, low distortion, small field curvature and small size.

Description

An eyepiece optical system with a large field of view and a head-mounted display device technical field

The present invention relates to the field of optical technology, and more particularly, to an eyepiece optical system with a large viewing angle and a head-mounted display device.

Background technique

With the continuous development of electronic devices towards ultra-miniaturization, as well as the development of new computer, microelectronics, optoelectronic devices and communication theories and technologies, wearable computing, a new model based on "people-oriented" and "human-machine integration" has become possible. . Applications continue to emerge in military, industrial, medical, education, consumer and other fields. In a typical wearable computing system architecture, the head-mounted display device is a key component. The head-mounted display device guides the video image light emitted by the miniature image display (such as transmissive or reflective liquid crystal display, organic electroluminescent device, DMD device) to the user's pupil through optical technology, and the user's near vision The scope realizes virtual and enlarged images, and provides users with intuitive and visible images, videos, and text information. The eyepiece optical system is the core of the head-mounted display device, which realizes the function of displaying a miniature image in front of the human eyes to form a virtual magnified image.

The head-mounted display device is developing towards the direction of compact size, light weight, easy to wear on the head and lightening of the load. At the same time, large field of view and visual comfort have gradually become the key factors to measure the quality of head-mounted display devices. Large field of view determines the effect of high-presence visual experience, and high image quality and low distortion determine the comfort of visual experience. Spend. To meet these requirements, it is necessary for the eyepiece optical system to achieve a large field of view, high image resolution, low distortion, small field curvature, and small volume as much as possible. At the same time, satisfying the above optical performance is very important for system design and aberration optimization. challenge.

Fresnel structures adopted in Patent Document 1 (Chinese Patent Publication No. CN109416469A), Patent Document 2 (Chinese Patent Publication No. CN105759424B), Patent Document 3 (Chinese Patent Publication No. CN107015361B), and Patent Document 4 (Chinese Patent Publication No. CN111381371A) Although good focusing effects can be achieved in the optical system, Patent Document 1 and Patent Document 3 completely rely on Fresnel lenses, while Patent Documents 2 and 4 are Fresnel lenses and single and double positive lenses. Combined, it is inevitable that it is difficult to make achievements in the aberration of the optical system, and there is a large distortion and spherical aberration.

Patent Document 5 (Chinese Patent Publication No. CN105278109A) provides an optical system using a combination of positive, negative, and positive lens groups, and provides an optical system that uses a combination of positive, negative, and positive lens groups. It is a traditional spherical and even-order aspheric optical system. Although it has great advantages in aberration correction, it is extremely cumbersome under the same optical system parameters.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide an eyepiece optical system and a head-mounted display device with a large field of view in view of the above-mentioned defects of the prior art, which can achieve a large field of view, high image resolution, low distortion, and a small field of view. Curve, small volume and other indicators.

The technical solution adopted by the present invention to solve the technical problem is: constructing an eyepiece optical system with a large field of view, comprising a first lens group, a first lens group, a second lens group, a Two lens groups and a third lens group, and the optical focal lengths of the first lens group, the second lens group and the third lens group are a combination of positive, negative and positive; the first lens group consists of two lenses Optical lenses are composed of a first lens close to the human eye side and a second lens away from the human eye side; the first lens group includes at least two Fresnel optical surfaces; the first lens includes at least one of the Fresnel optical surface;

The optical focal length of the optical system is set to F, and the optical focal length of the first lens group is set to f ₁ , then F and f ₁ satisfy the following relational formula (1):

0.50≤f ₁ /F≤1.33 (1);

The second lens group is composed of two optical lenses; wherein the second lens group includes a third lens and a fourth lens adjacent to the first lens group and arranged in sequence along the optical axis; the third lens and the fourth lens are both negative lenses;

The third lens group is composed of an optical lens; wherein the third lens group includes a fifth lens adjacent to the second lens group; the fifth lens is a positive lens;

The material properties of the first lens and the second lens satisfy the following relational expressions (2) and (3):

1.49<Nd ₁₁ <1.70 (2);

1.49<Nd ₁₂ <1.70 (3);

Wherein, Nd ₁₁ and Nd ₁₂ are the refractive indices of the first lens and the second lens at the d-line, respectively.

Further, the optical focal length f ₁₁ of the first lens and the optical focal length f ₁ of the first lens group satisfy the following relational formula (4):

1.50≤f ₁₁ /f ₁ ≤4.48 (4).

Further, each of the first lens and the second lens includes one of the Fresnel optical surfaces.

Further, the two Fresnel optical surfaces are arranged adjacent to each other.

Further, the base surfaces of the two Fresnel optical surfaces are plane or aspherical.

Further, the optical focal length of the optical system is F; the optical power of the second lens group is set to f ₂ , and F and f ₂ satisfy the following relational formula (5):

-0.98≤f ₂ /F≤-0.35 (5).

Further, if the optical focal length of the first lens group is f ₁ , and the optical power of the third lens group is f ₃ , then f ₁ and f ₃ satisfy the following relational formula (6):

0.02≦f ₁ /f ₃ ≦2.15 (6).

Further, the two Fresnel optical surfaces are both plane base Fresnel optical surfaces.

Further, the expression of aspheric surface is:

Further, both the first lens and the second lens include at least one even-order aspheric optical surface; the optical surfaces of the third lens and the fourth lens are both even-order aspheric surfaces.

Further, the third lens is a biconcave lens.

Further, the materials of the third lens, the fourth lens and the fifth lens are all optical glass or optical resin.

Further, the fifth lens is a biconvex lens.

Further, the optical film on the side away from the human eye of the fourth lens is convex toward the human eye.

The present invention also provides a head-mounted display device, comprising a microdisplay and an eyepiece; the eyepiece is located between the human eye and the microdisplay; the eyepiece is the eyepiece optical system described in any one of the foregoing.

Further, the microdisplay is an organic electroluminescence light-emitting device, a transmissive liquid crystal display or a reflective liquid crystal display.

Further, the head-mounted display device includes two identical and symmetrically arranged eyepiece optical systems.

The beneficial effects of the invention are: a combination of a double Fresnel optical surface type and a traditional optical spherical surface and aspherical surface type is adopted, and the combination of positive, negative and positive lens groups and the focal length of each lens can meet specific matching conditions. While achieving the advantages of large field of view, high image quality, low distortion, small field curvature, small volume and other indicators under the condition of It reduces the sensitivity of each optical component, facilitates the processing and assembly of the components, further improves the field of view, field curvature, distortion and other indicators in the optical system, and greatly improves the user's visual comfort experience. Through the eyepiece optical system of the present invention, an observer can watch a large-scale picture with full-frame high-definition, no distortion, and uniform image quality, so as to achieve a high-presence visual experience.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the present invention will be further described below with reference to the accompanying drawings and embodiments. Ordinary technicians can also obtain other drawings based on these drawings without creative labor:

1 is a schematic structural diagram of an eyepiece optical system according to a first embodiment of the present invention;

FIG. 2 is a schematic diagram of a diffused spot array of the eyepiece optical system according to the first embodiment of the present invention;

Fig. 3 is the distortion schematic diagram of the eyepiece optical system of the first embodiment of the present invention;

4 is a schematic diagram of the optical transfer function MTF of the eyepiece optical system according to the first embodiment of the present invention;

5 is a schematic structural diagram of an eyepiece optical system according to a second embodiment of the present invention;

6 is a schematic diagram of a speckle array of an eyepiece optical system according to a second embodiment of the present invention;

Fig. 7 is the distortion schematic diagram of the eyepiece optical system of the second embodiment of the present invention;

8 is a schematic diagram of the optical transfer function MTF of the eyepiece optical system of the second embodiment of the present invention;

9 is a schematic structural diagram of an eyepiece optical system according to a third embodiment of the present invention;

10 is a schematic diagram of a diffused spot array of an eyepiece optical system according to a third embodiment of the present invention;

11 is a schematic diagram of the distortion of the eyepiece optical system according to the third embodiment of the present invention;

12 is a schematic diagram of the optical transfer function MTF of the eyepiece optical system according to the third embodiment of the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the following will be described clearly and completely in combination with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, and Not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

The present invention constructs an eyepiece optical system with a large field of view, comprising a first lens group, a second lens group and a third lens group that are coaxially arranged in sequence along the optical axis from the observation side of the human eye to the microdisplay side, and the third lens group is The optical focal lengths of the first lens group, the second lens group and the third lens group are a combination of positive, negative and positive; the first lens group is composed of two optical lenses, the first lens on the side close to the human eye and the side away from the human eye. the second lens; the first lens group includes at least two Fresnel optical surfaces; the first lens includes at least one Fresnel optical surface;

The optical focal length of the optical system is set to F, and the optical focal length of the first lens group is set to f ₁ , then F and f ₁ satisfy the following relational formula (1):

0.50≤f ₁ /F≤1.33 (1);

Wherein, f ₁ /F can be 0.50, 0.53, 0.67, 0.87, 0.99, 1.21, 1.29, 0.33 and so on.

The second lens group is composed of two optical lenses; the second lens group includes a third lens and a fourth lens that are adjacent to the first lens group and arranged in sequence along the optical axis; the third lens and the fourth lens are both negative lenses ;

The third lens group is composed of an optical lens; wherein the third lens group includes a fifth lens adjacent to the second lens group; the fifth lens is a positive lens;

The material properties of the first lens and the second lens satisfy the following relational expressions (2), (3):

1.49<Nd ₁₁ <1.70 (2);

1.49<Nd ₁₂ <1.70 (3);

Wherein, Nd ₁₁ and Nd ₁₂ are the refractive indices of the first lens and the second lens at the d-line, respectively. The wavelength of the d-line is 589.3nm, and the materials of the first lens and the second lens are optional: E48R, K26R, EP3000, OKP1, etc.

Among them, the first lens group, the second lens group and the third lens group adopt a combination of positive, negative and positive, and each lens in the second lens group and the third lens group adopts a combination of negative, negative and positive to fully correct The aberration of the system is reduced, and the optical resolution of the system is improved. More importantly, the structure of double Fresnel surfaces is adopted in the first lens group, which shares most of the optical power in the optical system, effectively reduces the difference in the outer diameter of each lens, and reduces the size of the eyepiece. The overall size of the optical system improves the reliability of subsequent mass production. And the second lens group can provide enough negative refractive power to ensure that the eyepiece optical system can achieve a large enough angle of view. At the same time, optical indicators such as large field of view, low distortion, low chromatic aberration, low field curvature, and low astigmatism are realized. Through the eyepiece optical system, the observer can watch a large picture with full-frame high-definition, no distortion and uniform image quality. Achieving a highly immersive visual experience. This product is intended for use with head mounted displays and similar devices.

As shown in FIG. 1, it includes a first lens group, a second lens group, and a third lens group arranged in sequence along the optical axis direction from the observation side of the human eye to the micro-image display; The surface number is 1, and so on (from left to right: 2, 3, 4, 5, 6...), the light emitted from the micro-image display goes through the third lens group, the second lens group , After the first lens group is refracted, it enters the human eye.

In a further embodiment, the optical focal length f ₁₁ of the first lens and the optical focal length f ₁ of the first lens group satisfy the following relational formula (4):

1.50≤f ₁₁ /f ₁ ≤4.48 (4).

Wherein, f ₁₁ /f ₁ can be 1.50, 1.62, 1.83, 1.95, 2.21, 2.75, 2.98, 3.5, 3.89, 4.31, 4.48 and so on.

In a further embodiment, the first lens and the second lens respectively include a Fresnel optical surface.

In a further embodiment, the two Fresnel optical surfaces are arranged adjacently.

In the above embodiment, the double Fresnel optical surfaces in the eyepiece optical system are respectively arranged on the first lens and the second lens, and are arranged in an adjacent manner, that is, the optical surface of the first lens away from the human eye is Fresnel. The ear surface, the optical surface of the second lens close to the human eye side is the Fresnel surface. The structure of double Fresnel surfaces is adopted, which shares most of the optical power in the optical system, effectively reduces the difference in the outer diameter of each lens, reduces the overall size of the eyepiece optical system, and improves the follow-up volume. production reliability.

In a further embodiment, the optical focal length of the optical system is F; the optical power of the second lens group is set to f ₂ , and F and f ₂ satisfy the following relational formula (5):

-0.98≤f ₂ /F≤-0.35 (5).

Wherein, f ₂ /F can be -0.98, -0.95, -0.82, -0.77, -0.57, -0.49, -0.41, -0.38, -0.35 and so on.

In a further embodiment, the optical focal length of the first lens group is f ₁ , and the optical power of the third lens group is f ₃ , then f ₁ and f ₃ satisfy the following relational formula (6):

0.02≦f ₁ /f ₃ ≦2.15 (6).

Wherein, f ₁ /f ₃ can be 0.02, 0.32, 0.47, 0.67, 0.89, 1.32, 1.55, 1.89, 2.01, 2.11, 2.15 and so on.

The value ranges of f ₁ /F, f ₁₁ /f ₁ , f ₂ /F and f ₁ /f ₃ are closely related to the correction of system aberrations, the processing difficulty of optical components, and the sensitivity of optical component assembly deviations. The value of f ₁ /F in formula (1) is greater than 0.5, so that the aberration of the system can be fully corrected, so as to achieve high-quality optical effects, and the value of f 1 /F is less than 1.33, which improves the machinability of the optical elements in the system; relation; In formula (4), the value of f ₁₁ /f ₁ is greater than 1.5, so that the aberration of the system can be fully corrected, thereby achieving high-quality optical effects, and the value of f 11 /f 1 is less than 4.48, which improves the processability of the optical elements in the system; The value of f ₁ /f ₃ in the relation (6) is greater than 0.02, so that the aberration of the system can be fully corrected, thereby achieving high-quality optical effects, and the value of f 1 /f 3 is less than 2.15, which improves the machinability of the optical elements in the system . The value of f ₂ /F in the relationship (5) is greater than -0.95, so that the corresponding lens can provide sufficient negative power, so as to better balance and correct system aberrations and achieve good optical effects. Less than -0.35 reduces the difficulty of spherical aberration correction and facilitates the realization of large optical apertures.

In a further embodiment, the base surfaces of the two Fresnel optical surfaces are plane or aspherical.

In a further embodiment, both the first lens and the second lens include at least one even-order aspheric optical surface; the optical surfaces of the third lens and the fourth lens are both even-order aspheric surfaces.

The aberrations at all levels of the optical system are further optimized and corrected. The optical performance of the eyepiece optical system is further improved.

In a further embodiment, the expression for the aspheric surface is:

Among them, z is the sag of the optical surface, c is the curvature at the vertex of the aspheric surface, k is the aspheric coefficient, α2, 4, 6... are the coefficients of each order, and r is the distance coordinate from the point on the surface to the optical axis of the lens system.

The aberrations of the optical system (including spherical aberration, coma, distortion, field curvature, astigmatism, chromatic aberration and other higher-order aberrations) are fully corrected, which is beneficial for the eyepiece optical system to achieve a large field of view , At the same time of large aperture, the image quality of the central field of view and the edge of the field of view is further improved, the difference between the image quality of the center and the edge of the field of view is reduced, and the image quality and low distortion in the full frame are more uniform.

In a further embodiment, the third lens is a biconcave lens.

In a further embodiment, the fifth lens is a biconvex lens.

In a further embodiment, the optical film on the side of the fourth lens away from the human eye is convex toward the human eye.

The above-mentioned embodiments further improve aberrations such as astigmatism and field curvature of the system, which is beneficial for the eyepiece system to achieve a high-resolution optical effect of uniform image quality across the entire frame.

In a further embodiment, the materials of the third lens, the fourth lens and the fifth lens are all optical glass or optical resin. The aberrations of all levels of the eyepiece optical system are fully corrected, and the manufacturing cost of the optical element and the weight of the optical system are also controlled.

The principles, solutions and display results of the above-mentioned eyepiece optical system will be further described below through more specific embodiments.

In the following embodiments, the diaphragm E may be the exit pupil of the eyepiece optical system for imaging, which is a virtual light exit aperture. When the pupil of the human eye is at the diaphragm position, the best imaging effect can be observed.

first embodiment

The eyepiece design data of the first embodiment are shown in Table 1 below:

Table I

1 is a 2D structural diagram of the eyepiece optical system of the first embodiment, including a first lens group D1, a second lens group D2 and a first lens group D1, a second lens group D2 and The third lens group D3, wherein the first lens group D1 is composed of the first lens L1 and the second lens L2, the optical surface 2 and the optical surface 3 of the first lens group D1 are composed of two Fresnel surfaces, and the second lens group D1 is composed of two Fresnel surfaces. Group D2 is a negative refractive power lens group composed of two negative refractive power optical lenses, namely the third lens L3 and fourth lens L4; the third lens group D3 is a positive refractive power composed of a positive refractive power optical lens The lens group, namely the fifth lens L5. The focal length F of the optical system is 20.71, the optical focal length f1 of the _first lens group D1 is 10.36, the optical power f2 of the _second lens group D2 is -20.30, and the optical power f3 of the third lens group _D3 is 518.12 , the optical focal length f ₁₁ of the Fresnel lens close to the human eye is 46.41, that is, f ₁ /F is 0.50, f ₁₁ /f ₁ is 4.48, f ₂ /F is -0.98, and f ₁ /f ₃ is 0.02 .

Accompanying drawing 2, accompanying drawing 3, accompanying drawing 4 are the scattered spot array diagram, the distortion diagram and the optical transfer function MTF diagram of the optical system, respectively, reflecting the light of each field of view in the present embodiment on the image plane (display device (IMG) ) has high resolution and small optical distortion in the unit pixel of ), the resolution per 10mm per unit period reaches more than 0.8, the aberration of the optical system is well corrected, and uniform and high optical performance can be observed through the eyepiece optical system. display image.

Second Embodiment

The eyepiece design data of the second embodiment are shown in Table 2 below:

Table II

5 is a 2D structural diagram of the eyepiece optical system of the second embodiment, including a first lens group D1, a second lens group D2 and a first lens group D1, a second lens group D2 and The third lens group D3, wherein the optical surface 2 and the optical surface 3 of the first lens group are composed of two Fresnel surfaces, and the second lens group D2 is composed of two negative refractive power optical lenses with negative refractive power. The lens group, the third lens group D3 is a positive refractive power lens group composed of a positive refractive power optical lens. The focal length F of the optical system is 22.22, the optical focal length f1 of the _first lens group D1 is 14.88, the optical power f2 of the _second lens group D2 is -12.96, and the optical power f3 of the third lens group _D3 is 25.29 , the optical focal length f ₁₁ of the Fresnel lens close to the human eye is 27.37, that is, f ₁ /F is 0.67, f ₁₁ /f ₁ is 1.84, f ₂ /F is -0.583, and f ₁ /f ₃ is 0.588 .

Fig. 6, Fig. 7, Fig. 8 are the scattered spot array diagram, the distortion diagram and the optical transfer function MTF diagram of the optical system, respectively, reflecting the light of each field of view in the present embodiment on the image plane (display device (IMG) ) has high resolution and small optical distortion in the unit pixel of ), the resolution per 10mm per unit period reaches more than 0.8, the aberration of the optical system is well corrected, and uniform and high optical performance can be observed through the eyepiece optical system. display image.

Third Embodiment

The eyepiece design data of the third embodiment are shown in Table 3 below:

Table 3

9 is a 2D structural diagram of the eyepiece optical system of the third embodiment, including a first lens group D1, a second lens group D2 and a first lens group D1, a second lens group D2 and The third lens group D3, wherein the optical surface 2 and the optical surface 3 of the first lens group D1 are composed of two Fresnel surfaces, and the second lens group D2 is composed of two negative optical lenses with negative optical power. The third lens group D3 is a positive refractive power lens group composed of a positive refractive power optical lens. The focal length F of the optical system is 17.88, the optical focal length f1 of the _first lens group D1 is 23.78, the optical power f2 of the _second lens group D2 is -6.26, and the optical power f3 of the third lens group _D3 is 11.06 , the optical focal length f ₁₁ of the Fresnel lens close to the human eye is 35.67, that is, f ₁ /F is 1.33, f ₁₁ /f ₁ is 1.50, f ₂ /F is -0.35, and f ₁ /f ₃ is 2.15 .

Fig. 10, Fig. 11, Fig. 12 are the diffused spot array diagram, distortion diagram and optical transfer function MTF diagram of the optical system, respectively, which reflect the light of each field of view in this embodiment on the image plane (display device (IMG) ) has high resolution and small optical distortion in the unit pixel of ), the resolution per 10mm per unit period reaches more than 0.7, the aberration of the optical system is well corrected, and uniform and high optical performance can be observed through the eyepiece optical system. display image.

The data of the above-mentioned embodiments one to three all meet the parameter requirements recorded in the summary of the invention, and the results are shown in the following table four:

Table 4

	f 1 /F	f 11 /f 1	f 2 /F	f 1 /f 3
Example 1	0.50	4.48	-0.98	0.02
Embodiment 2	1.33	1.50	-0.35	2.15
Embodiment 3	0.67	1.89	-0.74	0.55

The present invention also provides a head-mounted display device, comprising a microdisplay and an eyepiece; the eyepiece is located between the human eye and the microdisplay; and the eyepiece is the eyepiece optical system of any one of the foregoing.

Preferably, the microdisplay is an organic electroluminescent light-emitting device, a transmissive liquid crystal display or a reflective liquid crystal display.

Preferably, the head mounted display device comprises two identical and symmetrically arranged eyepiece optical systems.

To sum up, the eyepiece optical system of the above-mentioned embodiments of the present invention adopts a combination of a double Fresnel optical surface type and a traditional optical spherical and aspherical surface type, combined with a combination of positive, negative and positive lens groups and each lens The focal length of the optical system achieves the advantages of large field of view, high image quality, low distortion, small field curvature, small volume and other indicators under the condition of meeting specific matching conditions, and also greatly reduces the weight of the optical system. The system aberration is greatly eliminated, the sensitivity of each optical component is reduced, the processing and assembly of the components are easy, and the field of view, field curvature, distortion and other indicators in the optical system are further improved, and the user's visual comfort experience is greatly improved. Through the eyepiece optical system of the present invention, an observer can watch a large-scale picture with full-frame high-definition, no distortion, and uniform image quality, so as to achieve a high-presence visual experience.

It should be understood that, for those skilled in the art, improvements or changes can be made according to the above description, and all these improvements and changes should fall within the protection scope of the appended claims of the present invention.

Claims (15)

1. An eyepiece optical system with a large field of view, characterized in that it comprises a first lens group, a second lens group and a third lens group that are coaxially arranged in order along the optical axis from the observation side of the human eye to the side of the microdisplay, and The optical focal lengths of the first lens group, the second lens group and the third lens group are a combination of positive, negative and positive; the first lens group is composed of two optical lenses, which are respectively on the side close to the human eye. The first lens and the second lens away from the human eye side; the first lens group includes at least two Fresnel optical surfaces; the first lens includes at least one of the Fresnel optical surfaces;

   The optical focal length of the optical system is set to F, and the optical focal length of the first lens group is set to f ₁ , then F and f ₁ satisfy the following relational formula (1):

   0.50≤f ₁ /F≤1.33 (1);

   The second lens group is composed of two optical lenses; wherein the second lens group includes a third lens and a fourth lens adjacent to the first lens group and arranged in sequence along the optical axis; the third lens and the fourth lens are both negative lenses;

   The third lens group is composed of an optical lens; wherein the third lens group includes a fifth lens adjacent to the second lens group; the fifth lens is a positive lens;

   The material properties of the first lens and the second lens satisfy the following relational expressions (2) and (3):

   1.49<Nd ₁₁ <1.70 (2);

   1.49<Nd ₁₂ <1.70 (3);

   Wherein, Nd ₁₁ and Nd ₁₂ are the refractive indices of the first lens and the second lens at the d-line, respectively.
2. The eyepiece optical system with a large angle of view according to claim 1, wherein the optical focal length f ₁₁ of the first lens and the optical focal length f ₁ of the first lens group satisfy the following relational formula (4):

   1.50≤f ₁₁ /f ₁ ≤4.48 (4).
3. The eyepiece optical system with a large field of view according to claim 1, wherein the first lens and the second lens respectively include one of the Fresnel optical surfaces.
4. The eyepiece optical system with a large field of view according to claim 3, wherein the two Fresnel optical surfaces are arranged adjacent to each other.
5. The eyepiece optical system with a large field of view according to claim 1, wherein the optical focal length of the optical system is F; the optical power of the second lens group is set to f ₂ , and F and f ₂ satisfy The following relational formula (5):

   -0.98≤f ₂ /F≤-0.35 (5).
6. The eyepiece optical system with a large field of view according to claim 1, wherein the optical focal length of the first lens group is f ₁ , and the optical power of the third lens group is f ₃ , then f _1. f ₃ satisfies the following relational formula (6):

   0.02≦f ₁ /f ₃ ≦2.15 (6).
7. The eyepiece optical system with a large field of view according to claim 3, wherein the base surfaces of the two Fresnel optical surfaces are plane or aspherical.
8. The eyepiece optical system with a large field of view according to claim 1, wherein the first lens and the second lens both include at least one even-order aspheric optical surface; the third lens and all The optical surfaces of the fourth lens are all even-order aspheric surfaces.
9. The eyepiece optical system with a large field of view according to claim 1, wherein the third lens is a biconcave lens.
10. The eyepiece optical system with a large field of view according to claim 1, wherein the materials of the third lens, the fourth lens and the fifth lens are all optical glass or optical resin.
11. The eyepiece optical system with a large field of view according to claim 1, wherein the fifth lens is a biconvex lens.
12. The eyepiece optical system with a large field of view according to claim 1, wherein the optical film on the side of the fourth lens away from the human eye is convex toward the human eye.
13. A head-mounted display device, comprising a microdisplay and an eyepiece; the eyepiece is located between a human eye and the microdisplay; wherein the eyepiece is the eyepiece optical system according to any one of claims 1-12 .
14. The head-mounted display device according to claim 13, wherein the microdisplay is an organic electroluminescence light-emitting device, a transmissive liquid crystal display or a reflective liquid crystal display.
15. The head-mounted display device according to claim 13 or 14, wherein the head-mounted display device comprises two identical and symmetrically arranged eyepiece optical systems.

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