WO2022213381A1 - Optical system and video glasses - Google Patents

Abstract

An optical system (10) and video glasses (100), the optical system (10) comprising a first lens (101) having a positive focal power, a second lens (102) having a negative focal power, a third lens (103) having a positive focal power, a fourth lens (104) having a positive focal power, and a fifth lens (105) having a negative focal power, which are all sequentially disposed from the image side to the object side. The optical system (10) satisfies the expression: 1.7≤N1≤1.9, V1≥37, V4≥37 and 15≤V5≤24, wherein N1 is the refractive index of the first lens (101), V1 is the dispersion coefficient of the first lens (101), V4 is the dispersion coefficient of the fourth lens (104), and V5 is the dispersion coefficient of the fifth lens (105).

Description

Optical system and video glasses technical field

The present application relates to the field of optical technology, and in particular, to an optical system and video glasses.

Background technique

Video glasses are portable devices that can be directly worn on the user's body to facilitate people's life, learning and perception, such as Augmented Reality (AR) glasses, Virtual Reality (VR) glasses, flight control glasses , smart helmets, smart headbands, etc. At present, these video glasses mainly use a 0.7-inch display screen. The 0.7-inch display screen enables the video glasses to have a larger field of view, but the 0.7-inch display screen will lead to a larger product volume, causing users The wear remains unchanged, which reduces the user's experience.

SUMMARY OF THE INVENTION

Based on this, the embodiments of the present application provide an optical system and video glasses. The optical system is applied to the video glasses, which can realize miniaturization of the product and improve the field of view of the video glasses.

In a first aspect, an embodiment of the present application provides an optical system, the optical system includes: sequentially arranged from the image side to the object side:

a first lens having positive refractive power;

a second lens having negative refractive power;

The third lens has positive refractive power;

a fourth lens with positive refractive power;

a fifth lens with negative refractive power;

The optical system satisfies the following expression:

1.7≤N ₁ ≤1.9, V ₁ ≥37, V ₄ ≥37, 15≤V ₅ ≤24

Wherein, N ₁ is the refractive index of the first lens, V ₁ is the dispersion coefficient of the first lens, V ₄ is the dispersion coefficient of the fourth lens, and V ₅ is the dispersion coefficient of the fifth lens.

In an optional embodiment, the optical system satisfies the following expression:

_30≤V1≤85 ; and/or,

_{1.5≤N2≤1.8} and _19≤V2≤50 ; and/or,

_{1.5≤N3≤1.7} and _50≤V3≤70 ; and/or,

1.7≤N ₄ ≤1.9 and 30≤V ₄ ≤85

Wherein, _N2 is the refractive index of the second lens, N3 is the refractive index of the _third lens, _N4 is the refractive index of the fourth lens, V1 is the dispersion coefficient of the _first lens, V ₂ is the dispersion coefficient of the second lens, V ₃ is the dispersion coefficient of the third lens, and V ₄ is the dispersion coefficient of the fourth lens.

In an optional embodiment, the optical system satisfies the following expression: 20≦V ₄ +V ₅ ≦80.

In an optional embodiment, the optical system satisfies the following expression:

Wherein, c ₁₁ is the curvature radius of the image-side lens surface of the first lens, and c ₁₂ is the curvature radius of the object-side lens surface of the first lens.

In an optional embodiment, the object-side lens surface of the second lens is formed with an inflection point and satisfies the following expression:

c ₂₁ <0, c ₂₂ >0

Wherein, c ₂₁ is the curvature radius of the image-side lens surface of the second lens, and c ₂₂ is the curvature radius of the object-side lens surface of the second lens.

In an optional embodiment, the image-side lens surface of the third lens is formed with an inflection point and satisfies the following expression:

_c31 <0, c32 > ₀

Wherein, c ₃₁ is the curvature radius of the image-side lens surface of the third lens, and c ₃₂ is the curvature radius of the object-side lens surface of the third lens.

In an optional embodiment, the third lens further satisfies the following expression:

In an optional embodiment, the optical system satisfies the following expression:

0.2≤E _FFL /T _TL ≤0.6

Wherein, E _FFL is the effective focal length of the optical system, T _TL is the distance on the optical axis from the image-side lens surface of the first lens to the object surface of the optical system, and the object surface of the optical system is used for Placed as a display.

In an optional embodiment, the optical system satisfies the following expression:

7≤f ₁ ≤13; and/or, -9≤f ₂ <0; and/or, 0<f ₃ ≤200; and/or, 1.0≤f ₄ ≤10; and/or, -20.0≤f ₅ ≤−1.0; wherein, f ₁ to f ₅ are the focal lengths of the first to fifth lenses, respectively, and the unit of the focal length is millimeters.

In an optional embodiment, the optical system has the function of a far-sighted mirror and/or a near-sighted mirror.

In an optional embodiment, the optical system is used to image the picture displayed on the display screen to the human eye.

In an optional embodiment, the size of the display screen is less than or equal to 0.5 inches.

In an optional embodiment, the human eye has a predetermined distance on the optical axis from the image-side lens surface of the first lens, and the predetermined distance includes 11.5 mm.

In an optional embodiment, the air interval from the fifth lens to the object surface is different for different degrees of human eyes.

In an optional embodiment, some or all of the lenses of the optical system are glass lenses.

In an optional embodiment, the first lens and/or the fourth lens are glass lenses.

In an optional embodiment, some or all of the lenses of the optical system are aspherical lenses.

In an optional embodiment, the two lens surfaces of the aspheric lens include: one aspheric surface or two aspheric surfaces.

In a second aspect, an embodiment of the present application further provides video glasses, the video glasses include the optical system according to any one of the embodiments of the present application, and the optical system is configured between a human eye and the video glasses. Between the display screens, it is used to image the picture displayed on the display screen to the human eye.

The optical system and video glasses provided by the embodiments of the present application use the optical system provided by the embodiments of the present application. Since the optical system has a larger field of view and better imaging quality, the video glasses can be used in A smaller display screen (such as a 0.5-inch display screen) also has a larger viewing angle, thereby realizing the miniaturization of the product and improving the user's viewing experience.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not limiting of the present application.

Description of drawings

In order to explain the technical solutions of the embodiments of the present application more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. For those of ordinary skill, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic diagram of an application scenario of video glasses provided by an embodiment of the present application;

2a and 2b are schematic structural diagrams of video glasses provided by an embodiment of the present application;

3 is a schematic structural diagram of an optical system provided by an embodiment of the present application;

4 is a schematic structural diagram of a second lens provided by an embodiment of the present application;

5 is a schematic structural diagram of a third lens provided by an embodiment of the present application;

FIG. 6 is a schematic configuration diagram of an optical system provided by an embodiment of the present application.

Description of main components and symbols:

100, video glasses; 10, optical system; 101, first lens; 102, second lens; 103, third lens, 104, fourth lens; 105, fifth lens;

20. Housing; 30. Display screen; 301. Lens.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. The embodiments described below and features in the embodiments may be combined with each other without conflict.

It should also be understood that the terminology used in the specification of the application herein is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural unless the context clearly dictates otherwise.

It should also be further understood that, as used in this specification and the appended claims, the term "and/or" refers to and including any and all possible combinations of one or more of the associated listed items .

An embodiment of the present application proposes video glasses, which may include, but are not limited to, virtual reality (Virtual Reality, VR) glasses, augmented reality (Augmented Reality, AR) glasses, or flight control glasses. In some embodiments, the video glasses can be connected to a movable platform (such as an unmanned aerial vehicle, an unmanned ground robot, a handheld PTZ camera, etc.), and the video glasses can obtain image information collected by the movable platform , and display the acquired image information.

Specifically, as shown in FIG. 1 , the user can wear the video glasses 100, and the video glasses 100 display image information captured by the movable platform in real time, so that the user can control the movement of the movable platform according to the image information, thereby improving the user experience.

At present, the video glasses on the market mainly use a 0.7-inch display screen. The 0.7-inch display screen makes the video glasses have a larger field of view. However, the 0.7-inch display screen will cause the product to be larger, causing the user to wear the same, thereby reducing the cost of user experience.

In order to realize the miniaturization of the product, the video glasses will choose a smaller size display screen, such as a 0.5-inch display screen. Although choosing a small size display screen can realize the miniaturization of the product, it will also cause a larger field of view for displaying image information. Small, the field of view (FOV) of the 0.5-inch display is about 45°, which is relatively small and cannot provide a better sense of immersion, reducing the user experience.

In order to solve the above problems, the embodiment of the present application provides an optical system and video glasses, that is, the video glasses 100 use the optical system provided by the embodiment of the present application, which can realize the miniaturization of the product, and at the same time can improve the field of view angle, and further Improve user experience.

Figures 2a and 2b respectively show the structure of the video glasses 100 provided by the embodiments of the present application. As shown in Figures 2a and 2b, the video glasses 100 include an optical system 10, a casing 20 and a display screen 30, wherein the optical system 10 and the display screen 30 are both disposed on the casing 20, and the optical system 10 is arranged between the human eye and the display screen 30, and is used to image the picture displayed by the display screen 30 to the human eye.

In the embodiment of the present application, the size of the display screen 30 may be 0.7 inches, 0.5 inches or less than 0.5 inches.

It should be noted that if the size of the display screen is selected to be 0.7 inches, it will lead to a larger volume of the product, which is not conducive to the user's wearing. If the size of the display screen is selected to 0.5 inches, although the miniaturization of the product can be achieved, it will reduce the field of view of the product, thereby reducing the size of the product. user experience.

In some embodiments, in order to realize the miniaturization of the video glasses 100, the video glasses can choose a 0.5-inch display screen. Since the video glasses 100 use the optical system provided by the embodiment of the present application, even if a 0.5-inch display screen is used, it can still have a larger field of view, thereby allowing the user to have a better sense of immersion, thereby improving the user's experience. experience.

It should be noted that the field of view of video glasses using a 0.5-inch display screen currently on the market is about 45°, but after using the optical system provided by the embodiment of the present application, the field of view can reach more than 50°.

The housing 20 also includes a headband, so that the user can wear the video glasses on the head through the headband, thereby freeing his hands, and controlling the movement of the movable platform according to the viewed image information.

Please refer to FIG. 3. FIG. 3 shows the structure of an optical system 10 provided by an embodiment of the present application. The optical system 10 is arranged between the human eye and the display screen 30, and is used to image the picture displayed by the display screen 30 on the The human eye can improve the viewing angle of the user, thereby enhancing the user's sense of immersion.

As shown in FIG. 3 , the optical system 10 includes: a first lens 101 , a second lens 102 , a third lens 103 , a fourth lens 104 and a fifth lens 105 arranged in order from the image side Ima to the object side Obj.

The first lens 101 has positive refractive power, the second lens 102 has negative refractive power, the third lens 103 has positive refractive power, the fourth lens 104 has positive refractive power, and the fifth lens 105 has negative refractive power.

The optical system 10 satisfies the following expression:

1.7≤N ₁ ≤1.9, V ₁ ≥37, V ₄ ≥37, 15≤V ₅ ≤24 (1)

In Expression (1), N ₁ is the refractive index of the first lens 101 , V ₁ is the dispersion coefficient of the first lens 101 , V ₄ is the dispersion coefficient of the fourth lens 104 , and V ₅ is the dispersion coefficient of the fifth lens 105 coefficient.

The optical system provided by the above embodiment utilizes the combination of five lenses and the setting of specific parameters, which can improve the field of view. In practical applications, the optical system can be adapted to a 0.5-inch display screen, thereby realizing the miniaturization of video glasses. At the same time, it improves the field of view of video glasses. Specifically, the field of view of video glasses using a 0.5-inch display can be increased from 45° to 50°. Compared with a 0.7-inch display, it can not only reduce the volume of the product, but also The field of view is also comparable to or larger than the 0.7-inch display, which enhances the user's sense of immersion and thus improves the user's experience.

It should be noted that the limitation of the refractive index of the first lens 101 in the optical system 10 can be beneficial to the rapid light collection at a large angle of view, but it will also bring some chromatic aberration effects to the entire optical system accordingly. The dispersion coefficients of the first lens 101, the fourth lens 104 and the fifth lens 105 are further defined to eliminate the chromatic aberration caused by the refractive index of the first lens, thereby ensuring that the optical system has a larger field of view, and improving the optical system image quality.

It should be noted that the optical system provided by the embodiments of the present application is not limited to be applied to video glasses, but can also be applied to electronic devices similar to video glasses to increase the field of view displayed by the electronic device.

In some embodiments, in order to improve the imaging quality of the optical system, the optical system can also be defined to satisfy the following expression:

_30≤V1≤85 ; and/or, _{1.5≤N2≤1.8} and _19≤V2≤50 ; and/or,

_{1.5≤N3≤1.7} and _50≤V3≤70 ; and/or, _{1.7≤N4≤1.9} and 30≤V4≤85 ( ₂ )

In Expression (2), N ₂ is the refractive index of the second lens 102 , N ₃ is the refractive index of the third lens 103 , N ₄ is the refractive index of the fourth lens 104 , and V ₁ is the dispersion of the first lens 101 coefficients, V ₂ is the dispersion coefficient of the second lens 102 , V ₃ is the dispersion coefficient of the third lens 103 , and V ₄ is the dispersion coefficient of the fourth lens 104 . The optical system satisfying the expression (2) can reduce the chromatic aberration of the optical system, thereby improving the imaging quality of the optical system.

In some embodiments, the optical system 10 may also be defined to satisfy the expression: 20≦V ₄ +V ₅ ≦80. Through the coordination of the dispersion coefficients of the fourth lens 104 and the fifth lens 105, the dispersion of the optical system can be more effectively reduced, thereby improving the imaging quality.

In some embodiments, in order to improve the imaging quality of the optical system, the optical system can also be defined to satisfy the following expression:

In Expression (3), c ₁₁ is the radius of curvature of the image-side lens surface of the first lens 101 , and c ₁₂ is the radius of curvature of the object-side lens surface of the first lens 101 . An optical system that satisfies expression (3) is more conducive to the entry of a large angle of incident light rays while introducing smaller aberrations, thereby improving the field of view and imaging quality of the optical system.

In some embodiments, as shown in FIG. 4 , in order to increase the field of view of the optical system and improve the imaging quality of the optical system, the object-side lens surface _S22 of the second lens 102 may also be set to form an inflection point, specifically the inflection point tp ₂₂₁ and an inflection point tp ₂₂₂ , the inflection point tp ₂₂₁ and the inflection point tp ₂₂₂ are symmetrical with respect to the optical axis, and the second lens 102 also satisfies the following expression:

c ₂₁ <0, c ₂₂ >0 (4)

In Expression (4), c ₂₁ is the radius of curvature of the image-side lens surface S ₂₁ of the second lens 102 , and c ₂₂ is the radius of curvature of the object-side lens surface S ₂₂ of the second lens 102 .

It should be noted that the object-side lens surface _S22 of the second lens 102 is formed with an inflection point, which can also be described as: the object-side lens surface _S22 of the second lens 102 is formed with a convex surface near the paraxial (optical axis).

In some embodiments, as shown in FIG. 5 , in order to increase the field of view of the optical system and improve the imaging quality of the optical system, an inflection point may be formed on the image-side lens surface S ₃₁ of the third lens 103 , specifically the inflection point tp ₃₁₁ and the inflection point tp ₃₁₂ , the inflection point tp ₃₁₁ and the inflection point tp ₃₁₂ are symmetrical with respect to the optical axis, and the third lens 103 also satisfies the following expression:

c ₃₁ <0, c ₃₂ >0 (5)

In Expression (5), c ₃₁ is the radius of curvature of the image-side lens surface S ₃₁ of the third lens 103 , and c ₃₂ is the radius of curvature of the object-side lens surface S ₃₂ of the third lens 103 .

It should be noted that the image-side lens surface _S31 of the third lens 103 is formed with an inflection point, which can also be described as: the object-side lens surface _S31 of the third lens 103 is formed with a concave surface near the paraxial (optical axis).

In some embodiments, the second lens 102 and the third lens 103 of the optical system 10 may simultaneously satisfy Expression (4) and Expression (5), respectively, and the object-side lens surface S ₂₂ of the second lens 102 is formed with an inflection point An inflection point is formed with the image-side lens surface S ₃₁ of the third lens 103 , thereby further improving the viewing angle and imaging quality of the optical system.

In some embodiments, the object-side lens surface S ₂₂ of the second lens 102 is formed with a convex surface near the paraxial (optical axis), and the object-side lens surface S ₃₁ of the third lens 103 is formed near the paraxial (optical axis) The concave surface is adapted to ensure that the optical system has a large field of view and high imaging quality. Wherein the adaptation is that the shapes of the convex and concave surfaces are the same or approximately the same.

In some embodiments, in addition to having an inflection point and satisfying Expression (5), the third lens 103 also satisfies the following expression:

This is more conducive to the introduction of smaller aberrations while entering a large angle of incident light.

In some embodiments, in order to achieve miniaturization of products, the optical system 10 can also be defined to satisfy the following expressions:

0.2≤E _FFL /T _TL ≤0.6 (6)

In Expression (6), E _FFL is the effective focal length of the optical system 10 , _TTL is the distance on the optical axis from the image-side lens surface of the first lens 101 to the object surface of the optical system 10 , and the object surface of the optical system 10 For placing as a display. The optical system satisfying the expression (6) can keep the compression ratio of the lens periphery of the optical system small, and at the same time keep the miniaturization of the optical system, which is beneficial to the lightening of the optical system.

In the optical system shown in FIG. 3 , the lens 301 may be a lens corresponding to the display surface of the display screen, or a lens used to protect the display surface of the display screen. T _TL is the distance from the image-side lens surface of the first lens 101 to the object surface of the optical system 10 on the optical axis, specifically the distance from the vertex of the image-side lens surface of the first lens 101 to the lens 301 on the optical axis.

It should be noted that the size of the display screen placed on the object surface may be less than or equal to 0.5 inches. The small size of the display screen can realize the miniaturization of the product, due to the use of the optical system, and at the same time, it has a large field of view.

In some embodiments, the optical system may also be set to satisfy the following expressions: 7≦f ₁ ≦13; and/or, −9≦f ₂ <0; and/or, 0<f ₃ ≦200; and/or or, _{1.0≤f4≤10} ; and/or, _{-20.0≤f5≤} -1.0. Wherein, f ₁ to f ₅ are the focal lengths of the first lens 101 , the second lens 102 , the third lens 103 , the fourth lens 104 and the fifth lens 105 respectively, and the unit of the focal length is millimeters.

It should be noted that the optical system provided by the embodiments of the present application has the function of hyperopia and/or myopia, so the user can see clear images without additional glasses, thereby improving the user experience. Specifically, it can achieve hyperopia from 200° to myopia of 700°.

The optical system provided by the embodiment of the present application is different from the optical system for general imaging to the sensor in that the optical system provided by the embodiment of the present application is used to image the picture displayed on the display screen to the human eye.

In order to improve the imaging quality and the user's viewing experience, a preset distance on the optical axis from the image-side lens surface of the first lens 101 to the human eye may also be defined, for example, the preset distance may be 11.5 mm.

Specifically, if the optical system is applied to video glasses, the housing of the video glasses can be set so that the image-side lens surface of the first lens 101 of the optical system has the predetermined distance on the optical axis from the human eye.

In some embodiments, in order to improve the user's viewing experience, the air interval between the fifth lens 105 and the object surface may also be defined to be different for different degrees of human eyes. Different users may be hyperopia or myopia, or have different degrees of hyperopia and myopia. Therefore, the air interval between the fifth lens 105 and the object surface is set to adapt to different users, thereby improving the user experience.

In some embodiments, in order to improve the imaging quality of the optical system and realize the miniaturization of the optical system, some or all lenses of the optical system 10 may also be set as aspherical lenses, for example, the first lens 101 and the second lens 102 may be set. , the third lens 103 and the fourth lens 104 are all aspherical lenses, while the fifth lens 105 is a spherical lens.

It should be noted that the two lens surfaces of the aspheric lens include: one aspheric surface or two aspheric surfaces.

Exemplarily, for example, the image-side lens surface of the first lens 101 is a spherical surface, the object-side lens surface of the first lens 101 is aspherical, the image-side lens surface of the fifth lens 105 is aspherical, and the object-side lens surface of the fifth lens 105 The lens surface is spherical. By arranging spherical lens surfaces on both sides of the optical system and an aspherical surface in the middle part, the chromatic aberration of the optical system can be further reduced, thereby improving the imaging quality of the optical system.

In some embodiments, in order to further correct the optical system, one mirror surface of the aspherical lens or all aspherical lens surfaces may be high-order aspherical surfaces, and the high-order aspherical surfaces satisfy the following expression:

In expression (7), z is the rotational symmetry axis of the aspheric surface, c is the curvature of the center point; y is the radial coordinate, whose unit is the same as the unit length of the lens; k is the quadratic curve constant, a ₁ to a ₈ respectively represent The coefficients corresponding to each radial coordinate.

In some embodiments, in order to reduce the weight of the optical system, part of the lenses of the optical system 10 may be limited to use glass lenses. For example, the first lens 101 and/or the fourth lens 104 are glass lenses. Of course, in other embodiments, all lenses may be made of glass.

The specific numerical configuration of the optical system is given below in conjunction with the accompanying drawings and the table. The surface numbers 1, 2, 3, 4, 6, 7, 8, 9... in the table represent the surface numbers in the optical system, respectively. Mirror surfaces and corresponding surfaces of the first lens 101 , the second lens 102 , the third lens 103 , the fourth lens 104 and the fifth lens 105 .

Specifically, as shown in FIG. 5 , the two lens surfaces of the first lens 101 are the surface F2 and the surface F3 respectively, the two lens surfaces of the second lens 102 are the surface F4 and the surface F5 respectively, and the two lens surfaces of the third lens 103 The lens surfaces are respectively the surface F6 and the surface F7, the two lens surfaces of the fourth lens 104 are the surface F8 and the surface F9 respectively, the two lens surfaces of the fifth lens 105 are the surface F10 and the surface F11 respectively, and the two mirror surfaces of the lens 301 They are the surface F12 and the surface F13 respectively, and the surface F1 is where the human eye is located. The serial number of the surface corresponds to the serial number of the surface under Surf in Table 1.

In Table 1, the number of surfaces (Surf) represents the surface of the lens, the type represents the shape of the surface, "STANDRAD" represents a plane, "EVENASPH" represents an aspheric surface; the radius of curvature (Radius) represents the degree of curvature of the lens surface, which can be represented by R , the smaller the R value, the more curved the lens surface; the interval or thickness (Thickness), the interval is expressed as the separation distance between the lenses of the optical system on the optical axis, and the thickness is the central thickness of the lens; ND is the refractive index of the lens; VD Indicates the dispersion coefficient of the lens, also known as the Abbe coefficient; "Infinity" refers to the plane. CT0 represents different object distances, representing users with different degrees of nearsightedness or farsightedness, and CT1 represents the air interval between the fifth lens 105 and the object surface, specifically the distance on the optical axis from the surface F11 to the surface F12.

In Table 2, Surf represents the number of faces, K is a quadratic curve constant, "4th-order term" to "10th-order term" indicate that a ₂ to a ₅ represent the coefficients corresponding to each radial coordinate, respectively. appears, the coefficients are all zero.

In Tables 1 and 3, CT0 represents different object distances, representing users with different degrees of myopia or hyperopia, and CT1 represents the air interval from the fifth lens 105 to the object surface, specifically the distance between surfaces F11 and F12 on the optical axis. Distance in millimeters.

It should be noted that Table 1 shows the specific parameters of the optical system, which is referred to as Example 1.

Table 1 is the surface parameter data of the lens of the optical system of Example 1

Surf	Type	Radius	Thickness	ND	VD
0	STANDARD	Infinity	CTO
1	STANDARD	Infinity	11.5
2	EVENASPH	23.08	4.80	1.88	37.2
3	EVENASPH	-15.47	1.83
4	EVENASPH	-5.21	2.55	1.64	22.4
5	EVENASPH	249.25	0.27
6	EVENASPH	-34.20	4.03	1.54	56
7	EVENASPH	-24.11	0.19
8	EVENASPH	8.23	7.08	1.88	37.2
9	EVENASPH	-37.11	0.12
10	STANDARD	-86.57	2.59	1.945	17.9
11	STANDARD	16.81	CT1
12	STANDARD	Infinity	0.700
13	STANDARD	Infinity	0.000
IMA		Infinity

Table 2 is the aspheric coefficient data of the optical system lens-surface of Example 1

surf	K	4th term	6th term	8th term	10 times
2	-0.598	7.21649E-05	-1.55226E-06	2.28885E-09	0.00000E+00
3	-9.827	2.58973E-04	-6.12435E-06	6.21583E-08	-2.45057E-10
4	-3.717	7.81935E-05	4.05557E-07	4.91050E-09	-6.40525E-11
5	98.999	-3.71370E-04	1.13710E-05	-1.09976E-07	3.60008E-10
6	0.000	3.20061E-04	-1.39274E-06	-6.84231E-09	7.73849E-11
7	-1.517	4.45317E-04	-7.11984E-06	3.79664E-08	-4.70434E-11
8	-0.879	-2.67254E-04	3.05216E-06	-1.68973E-08	1.87899E-11
9	2.075	1.57848E-04	-2.01660E-07	-1.16173E-08	7.09605E-11

Table 3 shows the air spacing of the optical system of Example 1 at different object distances

CT0	-1000	500	-143
CT1	3.811	4.357	2.702

It should be noted that, according to Example 1 given above, one of the parameters can be changed and then optical design can be performed to obtain more different optical systems. It should also be noted that the length units involved in the embodiments of the present application are millimeters, such as focal length, thickness, and distance.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalents within the technical scope disclosed in the present application. Modifications or substitutions shall be covered by the protection scope of this application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (19)

1. An optical system, characterized in that, the optical system comprises: sequentially arranged from the image side to the object side:

   a first lens having positive refractive power;

   a second lens having negative refractive power;

   The third lens has positive refractive power;

   a fourth lens with positive refractive power;

   the fifth lens, with negative refractive power;

   The optical system satisfies the following expression:

   1.7≤N ₁ ≤1.9, V ₁ ≥37, V ₄ ≥37, 15≤V ₅ ≤24

   Wherein, N ₁ is the refractive index of the first lens, V ₁ is the dispersion coefficient of the first lens, V ₄ is the dispersion coefficient of the fourth lens, and V ₅ is the dispersion coefficient of the fifth lens.
2. The optical system according to claim 1, wherein the optical system satisfies the following expression:

   _30≤V1≤85 ; and/or,

   _{1.5≤N2≤1.8} and _19≤V2≤50 ; and/or,

   _{1.5≤N3≤1.7} and _50≤V3≤70 ; and/or,

   1.7≤N ₄ ≤1.9 and 30≤V ₄ ≤85

   Wherein, _N2 is the refractive index of the second lens, N3 is the refractive index of the _third lens, _N4 is the refractive index of the fourth lens, V1 is the dispersion coefficient of the _first lens, V ₂ is the dispersion coefficient of the second lens, V ₃ is the dispersion coefficient of the third lens, and V ₄ is the dispersion coefficient of the fourth lens.
3. The optical system according to claim 1, wherein the optical system satisfies the following expression: 20≤V ₄ +V ₅ ≤80.
4. The optical system according to claim 1, wherein the optical system satisfies the following expression:

   

   Wherein, c ₁₁ is the curvature radius of the image-side lens surface of the first lens, and c ₁₂ is the curvature radius of the object-side lens surface of the first lens.
5. The optical system according to claim 1, wherein the object-side lens surface of the second lens is formed with an inflection point and satisfies the following expression:

   c ₂₁ <0, c ₂₂ >0

   Wherein, c ₂₁ is the curvature radius of the image-side lens surface of the second lens, and c ₂₂ is the curvature radius of the object-side lens surface of the second lens.
6. The optical system according to claim 1, wherein the image-side lens surface of the third lens is formed with an inflection point and satisfies the following expression:

   _c31 <0, c32 > ₀

   Wherein, c ₃₁ is the curvature radius of the image-side lens surface of the third lens, and c ₃₂ is the curvature radius of the object-side lens surface of the third lens.
7. The optical system according to claim 6, wherein the third lens further satisfies the following expression:

   
8. The optical system according to claim 1, wherein the optical system satisfies the following expression:

   0.2≤E _FFL /T _TL ≤0.6

   Wherein, E _FFL is the effective focal length of the optical system, T _TL is the distance on the optical axis from the image-side lens surface of the first lens to the object surface of the optical system, and the object surface of the optical system is used for Placed as a display.
9. The optical system according to claim 1, wherein the optical system satisfies the following expression:

   7≤f ₁ ≤13; and/or, -9≤f ₂ <0; and/or, 0<f ₃ ≤200; and/or, 1.0≤f ₄ ≤10; and/or, -20.0≤f ₅ ≤-1.0;

   Wherein, f ₁ to f ₅ are the focal lengths of the first to fifth lenses, respectively, and the unit of the focal length is millimeters.
10. The optical system according to claim 1, characterized in that, the optical system has a function of a far-sighted mirror and/or a near-sighted mirror.
11. The optical system according to any one of claims 1-10, characterized in that, the optical system is used to image the picture displayed on the display screen to the human eye.
12. The optical system according to claim 11, wherein the size of the display screen is less than or equal to 0.5 inches.
13. The optical system according to claim 11, wherein the human eye has a preset distance on the optical axis from the image-side lens surface of the first lens, and the preset distance includes 11.5 mm.
14. The optical system according to claim 11, wherein the air space between the fifth lens and the object surface is different for different degrees of human eyes.
15. The optical system according to any one of claims 1-10, wherein some or all of the lenses of the optical system are glass lenses.
16. The optical system according to claim 15, wherein the first lens and/or the fourth lens is a glass material lens.
17. The optical system according to any one of claims 1-10, wherein some or all of the lenses of the optical system are aspherical lenses.
18. The optical system according to claim 17, wherein the two lens surfaces of the aspherical lens comprise: one aspherical surface or two aspherical surfaces.
19. A kind of video glasses, characterized in that, the video glasses include the optical system according to any one of claims 1-18, the optical system is configured between a human eye and a display screen of the video glasses, and is used for The picture displayed on the display screen is imaged on the human eye.

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