阅读说明：本技术 目镜光学系统 (Eyepiece optical system ) 是由 黄峻洋 陈婉君 于 2018-07-16 设计创作，主要内容包括：本发明公开了一种目镜光学系统,用于使成像光线从显示画面经目镜光学系统进入观察者的眼睛而成像,朝向眼睛的方向为目侧,朝向显示画面的方向为显示侧,目镜光学系统从目侧至显示侧沿一光轴依序包括一第一透镜、一第二透镜及一第三透镜,第一透镜至第三透镜各自具有一目侧面及一显示侧面,第一透镜的目侧面的一光轴区域为凸面,第二透镜的目侧面的一圆周区域为凸面,且第三透镜的目侧面的一圆周区域为凹面。本发明可有效增加半眼视视角,并加强成像质量。(The invention discloses an eyepiece optical system, which is used for enabling imaging light to enter eyes of an observer from a display picture through the eyepiece optical system for imaging, wherein the direction facing the eyes is a eye side, the direction facing the display picture is a display side, the eyepiece optical system sequentially comprises a first lens, a second lens and a third lens from the eye side to the display side along an optical axis, the first lens to the third lens are respectively provided with an eye side surface and a display side surface, an optical axis area of the eye side surface of the first lens is a convex surface, a circumferential area of the eye side surface of the second lens is a convex surface, and a circumferential area of the eye side surface of the third lens is a concave surface. The invention can effectively increase the half-eye visual angle and enhance the imaging quality.)

1. An eyepiece optical system for causing an imaging light to enter an eye of an observer from a display screen through the eyepiece optical system to form an image, a direction toward the eye being a target side, a direction toward the display screen being a display side, characterized in that: the eyepiece optical system comprises a first lens, a second lens and a third lens in sequence from the eye side to the display side along an optical axis, wherein the first lens to the third lens are respectively provided with an eye side surface facing the eye side and enabling the imaging light to pass through and a display side surface facing the display side and enabling the imaging light to pass through;

an optical axis region of the eye side surface of the first lens is a convex surface;

a circumferential area of the eye-side surface of the second lens is convex;

a circumferential region of the eye side surface of the third lens is a concave surface; and

the eyepiece optical system conforms to: TL/G3D ≦ 4.600; and 0.800 ≦ G3D/(T1+ AAG),

wherein TL is a distance between the eye side surface of the first lens element and the display side surface of the third lens element on the optical axis, G3D is a distance between the third lens element and the display screen on the optical axis, T1 is a thickness of the first lens element on the optical axis, and AAG is a sum of two air gaps between the first lens element and the third lens element on the optical axis, and only the first lens element, the second lens element and the third lens element have refractive indices in the eyepiece optical system.

2. The eyepiece optical system of claim 1, wherein: the eyepiece optical system further satisfies G23/(G12+ T3) ≦ 2.000, where G23 is an air gap between the second lens and the third lens on the optical axis, G12 is an air gap between the first lens and the second lens on the optical axis, and T3 is a thickness of the third lens on the optical axis.

3. The eyepiece optical system of claim 1, wherein: the eyepiece optical system is further compliant with ALT/(T1+ G12+ T3) ≦ 1.700, where ALT is a sum of lens thicknesses of the first lens to the third lens on the optical axis, G12 is an air gap of the first lens to the second lens on the optical axis, and T3 is a thickness of the third lens on the optical axis.

4. The eyepiece optical system of claim 1, wherein: the eyepiece optical system further satisfies T2/T3 ≦ 2.300, where T2 is a thickness of the second lens on the optical axis, and T3 is a thickness of the third lens on the optical axis.

5. The eyepiece optical system of claim 1, wherein: the eyepiece optical system further satisfies TTL/(T3+ G3D) ≦ 2.500, where TTL is a distance between the object-side surface of the first lens and the optical axis of the display screen, and T3 is a thickness of the third lens on the optical axis.

6. The eyepiece optical system of claim 1, wherein: the eyepiece optical system further satisfies T1/T2 ≦ 1.400, where T2 is the thickness of the second lens on the optical axis.

7. The eyepiece optical system of claim 1, wherein: the eyepiece optics system further conforms to EFL/G3D ≦ 2.000, where EFL is the system focal length of the eyepiece optics system.

8. The eyepiece optical system of claim 1, wherein: the eyepiece optical system further satisfies T1/G23 ≦ 2.500, where G23 is an air gap on the optical axis from the second lens to the third lens.

9. The eyepiece optical system of claim 1, wherein: the eyepiece optical system further satisfies (AAG + T1)/T2 ≦ 2.300, where T2 is the thickness of the second lens on the optical axis.

10. The eyepiece optical system of claim 1, wherein: the eyepiece optical system is further compliant with ALT/T2 ≦ 3.300, where ALT is a sum of lens thicknesses of the first lens to the third lens on the optical axis, and T2 is a thickness of the second lens on the optical axis.

11. The eyepiece optical system of claim 1, wherein: the eyepiece optical system further satisfies AAG/G23 ≦ 1.200, where G23 is the air gap between the second lens and the third lens on the optical axis.

12. The eyepiece optical system of claim 1, wherein: the eyepiece optical system is further compatible with TL/G23 ≦ 6.800, where G23 is the air gap on the optical axis from the second lens to the third lens.

13. The eyepiece optical system of claim 1, wherein: the eyepiece optical system further satisfies (T1+ G12)/T2 ≦ 1.700, where G12 is an air gap between the first lens and the second lens on the optical axis, and T2 is a thickness of the second lens on the optical axis.

14. The eyepiece optical system of claim 1, wherein: the eyepiece optical system further satisfies (T1+ G12+ T2+ G23)/T3 ≦ 6.400, where G12 is an air gap between the first lens and the second lens on the optical axis, T2 is a thickness of the second lens on the optical axis, G23 is an air gap between the second lens and the third lens on the optical axis, and T3 is a thickness of the third lens on the optical axis.

15. The eyepiece optical system of claim 1, wherein: the eyepiece optical system further satisfies 3.100 ≦ ALT/AAG, where ALT is a sum of lens thicknesses of the first lens to the third lens on the optical axis.

16. The eyepiece optical system of claim 1, wherein: the eyepiece optics system is more compliant with 0.900 ≦ EFL/TL, where EFL is the system focal length of the eyepiece optics system.

17. The eyepiece optical system of claim 1, wherein: the eyepiece optical system further satisfies 1.800 ≦ TTL/ALT, where TTL is a distance on the optical axis from the eye side surface of the first lens to the display, and ALT is a sum of lens thicknesses on the optical axis of the first lens to the third lens.

18. The eyepiece optical system of claim 1, wherein: the eyepiece optical system further satisfies a value of TTL/TL which is more than or equal to 1.400, wherein TTL is a distance between the eye side surface of the first lens and the optical axis of the display picture.

19. The eyepiece optical system of claim 1, wherein: the eyepiece optical system further satisfies 1.300 ≦ (G12+ T2)/G23, where G12 is an air gap on the optical axis from the first lens to the second lens, T2 is a thickness of the second lens on the optical axis, and G23 is an air gap on the optical axis from the second lens to the third lens.

20. The eyepiece optical system of claim 1, wherein: the eyepiece optics system further satisfies 2.500 ≦ 250mm/EFL ≦ 25.000, where EFL is the system focal length of the eyepiece optics system.

Technical Field

The present invention relates to an optical system, and more particularly, to an eyepiece optical system.

Background

Virtual Reality (VR) is a virtual world that is simulated by computer technology to generate a three-dimensional space, and provides the user with sense simulation about vision, hearing, etc. to make the user feel that he/she is experiencing his/her own situation. The existing VR device is mainly used for visual experience. The parallax of human eyes is simulated by the divided pictures which are slightly different from the two visual angles of the left and right eyes, so as to achieve the stereoscopic vision. In order to reduce the size of the virtual reality device and make the user obtain the magnified visual sensation through a smaller display screen, an eyepiece optical system with a magnifying function has been one of the subjects of VR research and development.

The half-eye viewing angle of the existing eyepiece optical system is small, so that an observer feels that the vision is narrow, the resolution is low, the aberration compensation needs to be performed before the display picture is seriously affected, and in addition, the aberration is obvious and the requirement of a user is difficult to meet. Therefore, how to increase the half-eye viewing angle and enhance the imaging quality is a problem to be improved in the eyepiece optical system.

Disclosure of Invention

An objective of the present invention is to provide an eyepiece optical system, which can effectively increase the half-eye viewing angle and enhance the imaging quality.

An embodiment of the present invention provides an eyepiece optical system, configured to enable an imaging light to enter an eye of an observer from a display screen through the eyepiece optical system to form an image, where a direction toward the eye is a target side and a direction toward the display screen is a display side, the eyepiece optical system sequentially includes a first lens, a second lens, and a third lens from the target side to the display side along an optical axis, each of the first lens to the third lens has a target side surface facing the target side and allowing the imaging light to pass through and a display side surface facing the display side and allowing the imaging light to pass through, an optical axis region of the target side surface of the first lens is a convex surface, a circumferential region of the target side surface of the second lens is a convex surface, and a circumferential region of the target side surface of the third lens is a concave surface, and the eyepiece optical system meets the following requirements: TL/G3D ≦ 4.600; and 0.800 ≦ G3D/(T1+ AAG), where TL is an axial distance between an object side surface of the first lens element and a display side surface of the third lens element, G3D is an axial distance between the third lens element and the display screen, T1 is an axial thickness of the first lens element, and AAG is a sum of three air gaps between the first lens element and the third lens element, and only the first lens element, the second lens element, and the third lens element are included in the eyepiece optical system.

In view of the above, since an optical axis region of the eye-side surface of the first lens element of the eyepiece optical system of the embodiment of the invention is a convex surface, a circumferential region of the eye-side surface of the second lens element is a convex surface, and a circumferential region of the eye-side surface of the third lens element is a concave surface, the half-eye viewing angle of the eyepiece optical system can be effectively increased, and the imaging quality of the eyepiece optical system can be enhanced.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

FIG. 1 is a schematic view of an eyepiece optical system of the present invention;

FIG. 2 is a schematic view of a face structure of a lens of the present invention;

FIG. 3 is a schematic diagram showing the relationship between the surface-type convexo-concave structure and the light focus of a lens according to the present invention;

FIG. 4 is a schematic view of a face structure of a lens according to an example I;

FIG. 5 is a schematic view of a face structure of a lens according to example two;

FIG. 6 is a schematic view of the surface structure of a lens according to example III;

fig. 7 is a schematic view of an eyepiece optical system of a first embodiment of the present invention;

fig. 8a to D are longitudinal spherical aberration diagrams and aberration diagrams of the eyepiece optical system of the first embodiment;

fig. 9 is detailed optical data of the eyepiece optical system of the first embodiment of the present invention;

FIG. 10 shows aspheric parameters of the eyepiece optics of the first embodiment of the present invention;

fig. 11 is a schematic view of an eyepiece optical system of a second embodiment of the present invention;

fig. 12a to D are longitudinal spherical aberration diagrams and aberration diagrams of the eyepiece optical system of the second embodiment;

fig. 13 is detailed optical data of an eyepiece optical system of a second embodiment of the present invention;

fig. 14 is an aspherical parameter of an eyepiece optical system of a second embodiment of the present invention;

fig. 15 is a schematic view of an eyepiece optical system of a third embodiment of the present invention;

fig. 16a to D are longitudinal spherical aberration diagrams and aberration diagrams of the eyepiece optical system of the third embodiment;

fig. 17 is detailed optical data of an eyepiece optical system of a third embodiment of the present invention;

fig. 18 is an aspherical parameter of an eyepiece optical system of a third embodiment of the present invention;

fig. 19 is a schematic view of an eyepiece optical system of a fourth embodiment of the present invention;

fig. 20a to D are longitudinal spherical aberration diagrams and aberration diagrams of the eyepiece optical system of the fourth embodiment;

fig. 21 is detailed optical data of an eyepiece optical system of a fourth embodiment of the present invention;

fig. 22 is an aspherical parameter of an eyepiece optical system of a fourth embodiment of the present invention;

fig. 23 is a schematic view of an eyepiece optical system of a fifth embodiment of the present invention;

fig. 24a to D are longitudinal spherical aberration and various aberration diagrams of the eyepiece optical system of the fifth embodiment;

fig. 25 is detailed optical data of an eyepiece optical system of a fifth embodiment of the present invention;

fig. 26 is an aspherical parameter of an eyepiece optical system of a fifth embodiment of the present invention;

fig. 27 is a schematic view of an eyepiece optical system of a sixth embodiment of the present invention;

fig. 28a to D are longitudinal spherical aberration diagrams and aberration diagrams of the eyepiece optical system of the sixth embodiment;

fig. 29 is detailed optical data of an eyepiece optical system of a sixth embodiment of the present invention;

fig. 30 is an aspherical parameter of an eyepiece optical system of a sixth embodiment of the present invention;

fig. 31 is numerical values of important parameters and their relational expressions of the eyepiece optical systems of the first to sixth embodiments of the present invention.

Description of the symbols

0 pupil

1 first lens

10. V100 eyepiece optical system

100. 200, 300, 400, 500 lens

130 assembly part

15. 25, 35, 110, 410, 510 mesh side

16. 26, 36, 120, 320 show the sides

2 second lens

211. 212 parallel light ray

3 third lens

99. V50 display Screen

Side of mesh A1

A2 display side

CP center point

CP1 first center point

CP2 second center point

D1 exit pupil diameter

D2 shows the diameter of the image circle

EL extension line

I optical axis

Lm marginal ray

Lc chief ray

OB optical boundary

M, R intersection point

TP1 first transition Point

TP2 second transition Point

V60 eye

VD virtual image distance

VI imaging ray

VV amplified virtual image

Optical axis region of Z1, 151, 161, 251, 261, 352, 361, 362

Circumferential zones Z2, 153, 154, 163, 253, 263, 354, 363, 364

Omega half visual angle

Z3 Relay zone

Detailed Description

To further illustrate the various embodiments, the invention provides the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the embodiments. With these references in mind, one skilled in the art will understand that other embodiments are possible and that the advantages of the invention are readily apparent. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.

The invention will now be further described with reference to the accompanying drawings and detailed description.

Generally, the light of the eyepiece optical system V100 is an imaging light VI emitted from the display screen V50, enters the eye V60 through the eyepiece optical system V100, is focused on the retina of the eye V60 and generates an enlarged virtual image VV at the virtual image distance VD, as shown in fig. 1. The criterion for explaining the optical specification of the present invention is to assume that the light direction reverse tracking (inverting tracking) is a parallel imaging light, and the parallel imaging light passes through the eyepiece optical system from the eye side to the display screen for focusing and imaging.

The optical system of the present specification includes at least one lens that receives an imaging light ray incident on the optical system within a half-eye view angle (ω) from parallel to an optical axis to relative to the optical axis. The imaging light is imaged on the display picture through the optical system. The term "a lens element having positive refractive index (or negative refractive index)" means that the paraxial refractive index of the lens element calculated by Gaussian optics theory is positive (or negative). The term "eye-side (or display-side) of a lens" is defined as the specific area of the lens surface through which the imaging light passes. The imaging light includes at least two types of light: a chief ray (chiefray) Lc and a marginal ray (marginal ray) Lm (see fig. 2). The lens' eye side (or display side) may be divided into different regions at different locations, including an optical axis region, a circumferential region, or in some embodiments one or more relay regions, the description of which will be described in detail below.

Fig. 2 is a radial cross-sectional view of the lens 100. Two reference points on the surface of the lens 100 are defined: a center point and a transition point. The center point of the lens surface is an intersection point of the surface and the optical axis I. As illustrated in FIG. 2, the first center point CP1 is located on the destination side 110 of the lens 100 and the second center point CP2 is located on the display side 120 of the lens 100. The transition point is a point on the lens surface, and a tangent to the point is perpendicular to the optical axis I. The optical boundary OB of a lens surface is defined as a point where a radially outermost marginal ray Lm passing through the lens surface intersects the lens surface. All transition points are located between the optical axis I and the optical boundary OB of the lens surface. In addition, if there are a plurality of transition points on a single lens surface, the transition points are sequentially named from the first transition point in the radially outward direction. For example, a first transition point TP1 (closest to the optical axis I), a second transition point TP2 (shown in fig. 5), and an nth transition point (farthest from the optical axis I).

A range from the center point to the first transition point TP1 is defined as an optical axis region, wherein the optical axis region includes the center point. The area radially outward of the nth switching point farthest from the optical axis I to the optical boundary OB is defined as a circumferential area. In some embodiments, a relay area between the optical axis area and the circumferential area may be further included, and the number of relay areas depends on the number of transition points.

When a light ray parallel to the optical axis I passes through a region, the region is convex if the light ray is deflected toward the optical axis I and the intersection point with the optical axis I is located at the lens display side a 2. When a light ray parallel to the optical axis I passes through a region, the region is concave if the intersection of the extension line of the light ray and the optical axis I is located on the lens eye side a 1.

In addition, referring to FIG. 2, the lens 100 may further include an assembling portion 130 extending radially outward from the optical boundary OB. The assembling portion 130 is generally used for assembling the lens 100 to a corresponding element (not shown) of an optical system. The imaging light does not reach the assembling portion 130. The structure and shape of the assembling portion 130 are merely examples for illustrating the present invention, and the scope of the present invention is not limited thereto. The lens assembling portion 130 discussed below may be partially or entirely omitted in the drawings.

Referring to fig. 3, an optical axis region Z1 is defined between the center point CP and the first transition point TP 1. A circumferential zone Z2 is defined between the first transition point TP1 and the optical boundary OB of the lens surface. As shown in fig. 3, the parallel light ray 211 after passing through the optical axis region Z1 intersects the optical axis I at the display side a2 of the lens 200, i.e., the focal point of the parallel light ray 211 passing through the optical axis region Z1 is located at the R point of the display side a2 of the lens 200. Since the light ray intersects the optical axis I at the display side A2 of the lens 200, the optical axis region Z1 is convex. In contrast, the parallel rays 212 diverge after passing through the circumferential zone Z2. As shown in fig. 3, an extension line EL of the parallel ray 212 passing through the circumferential region Z2 intersects the optical axis I at the eye side a1 of the lens 200, i.e., the focal point of the parallel ray 212 passing through the circumferential region Z2 is located at point M of the eye side a1 of the lens 200. Since the extension line EL of the light ray intersects the optical axis I at the eye side A1 of the lens 200, the circumferential region Z2 is concave. In the lens 200 shown in fig. 3, the first transition point TP1 is a boundary between the optical axis region and the circumferential region, i.e., the first transition point TP1 is a boundary point between convex and concave surfaces.

On the other hand, the determination of the surface shape irregularity in the optical axis region may be performed by a method of determination by a person of ordinary skill in the art, that is, by determining the sign of the paraxial radius of curvature (abbreviated as R value) of the optical axis region surface shape irregularity of the lens. The R value may be commonly used in optical design software, such as Zemax or CodeV. The R value is also commonly found in lens data sheets (lens data sheets) of optical design software. When the value of R is positive, the optical axis area of the eye side surface is judged to be a convex surface; when the R value is negative, the optical axis area of the eye side surface is judged to be a concave surface. On the contrary, regarding the display side surface, when the R value is positive, the optical axis area of the display side surface is judged to be a concave surface; when the R value is negative, the optical axis area of the display side surface is judged to be convex. The result of the determination by the method is consistent with the result of the determination manner by the intersection point of the light/light extension line and the optical axis, namely, the determination manner of the intersection point of the light/light extension line and the optical axis is to determine the surface-shaped concave-convex by positioning the focus of the light parallel to the optical axis at the target side or the display side of the lens. As described herein, "a region is convex (or concave), or" a region is convex (or concave) "may be used interchangeably.

Fig. 4 to 6 provide examples of determining the surface shape and the zone boundary of the lens zone in each case, including the optical axis zone, the circumferential zone, and the relay zone described above.

Fig. 4 is a radial cross-sectional view of the lens 300. Referring to fig. 4, the display side 320 of the lens 300 presents only one transition point TP1 within the optical boundary OB. Fig. 4 shows an optical axis region Z1 and a circumferential region Z2 of the display side surface 320 of the lens 300. This shows that the R value of the side surface 320 is positive (i.e., R >0), and thus, the optical axis region Z1 is concave.

Generally, the shape of each region bounded by the transition point is opposite to the shape of the adjacent region, and thus the transition point can be used to define the transition of the shapes from concave to convex or from convex to concave. In fig. 4, since the optical axis region Z1 is concave and the surface transitions at the transition point TP1, the circumferential region Z2 is convex.

Fig. 5 is a radial cross-sectional view of lens 400. Referring to fig. 5, the eye side surface 410 of the lens 400 has a first transition point TP1 and a second transition point TP 2. An optical axis region Z1 between the optical axis I and the first transition point TP1 is defined as the eye side surface 410. The optical axis Z1 is convex because the R value of the eye side surface 410 is positive (i.e., R > 0).

A circumferential region Z2 is defined between the second transition point TP2 and the optical boundary OB of the eye side surface 410 of the lens 400, which circumferential region Z2 of the eye side surface 410 is also convex. In addition, a relay zone Z3 is defined between the first transition point TP1 and the second transition point TP2, and the relay zone Z3 of the destination side 410 is concave. Referring again to fig. 5, the eye side surface 410 includes, radially outward from the optical axis I, an optical axis region Z1 between the optical axis I and the first transition point TP1, a relay region Z3 between the first transition point TP1 and the second transition point TP2, and a circumferential region Z2 between the second transition point TP2 and the optical boundary OB of the eye side surface 410 of the lens 400. Since the optical axis region Z1 is convex, the surface shape changes from the first transition point TP1 to concave, the relay region Z3 is concave, and the surface shape changes from the second transition point TP2 to convex, so the circumferential region Z2 is convex.

Fig. 6 is a radial cross-sectional view of lens 500. The eye side 510 of the lens 500 has no transition point. For a lens surface without a transition point, such as the eye side surface 510 of the lens 500, an optical axis area is defined as 0-50% of the distance from the optical axis I to the optical boundary OB of the lens surface, and a circumferential area is defined as 50-100% of the distance from the optical axis I to the optical boundary OB of the lens surface. Referring to the lens 500 shown in fig. 6, 50% of the distance from the optical axis I to the optical boundary OB on the surface of the lens 500 from the optical axis I is defined as an optical axis region Z1 of the eye side surface 510. The optical axis Z1 is convex because the R value of the eye side surface 510 is positive (i.e., R > 0). Since the eye side 510 of the lens 500 has no transition point, the circumferential region Z2 of the eye side 510 is also convex. The lens 500 may further have an assembling portion (not shown) extending radially outward from the circumferential region Z2.

Fig. 7 is a schematic view of an eyepiece optical system according to a first embodiment of the present invention, and fig. 8a to D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system according to the first embodiment. Referring to fig. 7, the eyepiece optical system 10 of the first embodiment of the present invention is used to make the imaging light of the display image 99 enter the eye of the observer through the eyepiece optical system 10 and the pupil 0 of the eye of the observer to form an image, and the display image may be perpendicular to the optical axis or may form an angle different from 90 degrees with the optical axis. The eye side a1 is a side facing the direction of the eyes of the observer, and the display side a2 is a side facing the direction of the display screen 99. In the present embodiment, the eyepiece optical system 10 includes a first lens 1, a second lens 2, and a third lens 3 along an optical axis I in sequence from the eye side a1 to the display side a 2. When the image light of the display image 99 is emitted, the image light sequentially passes through the third lens element 3, the second lens element 2 and the first lens element 1, and then enters the eyes of the observer through the pupil 0 of the observer. The imaging light then forms an image on the retina of the observer's eye. Specifically, each of the first lens 1 to the third lens 3 of the eyepiece optical system 10 has an eye- side surface 15, 25, 35 that faces the eye side a1 and passes imaging light and a display- side surface 16, 26, 36 that faces the display side a2 and passes imaging light.

In addition, in order to satisfy the requirement of light weight of the product, the first lens element 1, the second lens element 2 and the third lens element 3 all have refractive indexes and are made of plastic materials, but the materials of the first lens element 1, the second lens element 2 and the third lens element 3 are not limited thereto. In the present embodiment, the lenses having refractive indexes in the eyepiece optical system 10 only include the first lens element 1, the second lens element 2 and the third lens element 3.

The first lens element 1 has a positive refractive index. The optical axis region 151 of the eye-side surface 15 of the first lens element 1 is convex, and the circumferential region 153 thereof is convex. The optical axis region 161 of the display side surface 16 of the first lens element 1 is convex, and the circumferential region 163 thereof is convex. The second lens element 2 has a positive refractive index. The optical axis region 251 of the eye side surface 25 of the second lens element 2 is convex, and the circumferential region 253 thereof is convex. In the present embodiment, the display side surface 26 of the second lens 2 is a Fresnel surface 265, i.e., a surface of a Fresnel lens. The surface of the Fresnel lens is provided with a plurality of concentric annular teeth which surround a central convex surface, and each annular tooth is provided with an effective sub-surface capable of refracting incident light to a preset direction and an ineffective sub-surface connecting two adjacent effective sub-surfaces. In addition, the central convex surface can refract incident light to a predetermined direction. The optical axis region 261 of the display side surface 26 of the second lens element 2 is convex, and the circumferential region 263 thereof is convex. The third lens element 3 has negative refractive index, and an optical axis region 352 of the eye-side surface 35 of the third lens element 3 is concave, and a peripheral region 354 thereof is concave. The optical axis region 362 of the display side 36 of the third lens element 3 is concave, and the circumferential region 363 thereof is convex.

Other detailed optical data for the first embodiment is shown in fig. 9. The eyepiece optical system 10 of the first embodiment has an overall system focal length (EFL) of 34.853 millimeters (mm) and a half-angle of view (ω)

And the aperture value (f-number, Fno) is 6.971. Specifically, the "aperture value" in the present specification is an aperture value calculated by regarding the pupil 0 of the observer as the entrance pupil based on the principle of reversibility of light. Further, the diameter (ICD) of a display image circle of the display screen 99 corresponding to the maximum viewing angle of the single eye of the observer of the eyepiece optical system 10 of the first embodiment is 49.5mm, where the display image circle is the maximum display screen range visible by the single eye of the observer through the eyepiece optical system 10, and the total lens length (TTL) of the eyepiece optical system 10 of the first embodiment is 41.200mm, where TTL is the distance from the eye side surface 15 of the first lens 1 to the display screen 99 on the optical axis I. In addition, the effective radius in fig. 9 means a half of the optically effective diameter (cleardiameter).

In the present embodiment, the eye side surfaces 15, 25 and 35 are aspheric surfaces, the display side surfaces 16 and 36 are aspheric surfaces, and the display side surface 26 is a fresnel surface 265, wherein the effective sub-surface and the central convex surface of each annular tooth of the fresnel surface 265 are aspheric surfaces, and the following aspheric coefficients of the display side surface 26 are used to represent the effective sub-surfaces and the central convex surfaces of the annular teeth of the fresnel surface 265, and the aspheric surfaces are defined by the following formulas:

wherein:

y: the vertical distance between a point on the aspheric curve and the optical axis I;

z: the depth of the aspheric surface (the vertical distance between a point on the aspheric surface which is Y away from the optical axis I and a tangent plane tangent to the vertex on the optical axis I of the aspheric surface);

r: the radius of curvature of the lens surface near the optical axis I;

k: cone constant (conc constant);

a_i: the ith order aspheric coefficients.

The aspheric coefficients of the object side surfaces 15, 25, 35 and the display side surfaces 16, 26, 36 in formula (1) are shown in fig. 10. In fig. 10, the column number 15 indicates the aspheric coefficient of the eye side surface 15 of the first lens 1, and so on.

Fig. 31 shows the relationship between the important parameters in the eyepiece optical system 10 of the first embodiment.

Wherein the content of the first and second substances,

the EFL is a system focal length of the eyepiece optical system 10, that is, an Effective Focal Length (EFL) of the eyepiece optical system 10;

ω is a half-angle of view (half-angle of view) of the eyepiece optical system 10, i.e., half the angle of the viewer's field of view, as shown in FIG. 1;

t1 is the thickness of the first lens 1 on the optical axis I;

t2 is the thickness of the second lens 2 on the optical axis I;

t3 is the thickness of the third lens 3 on the optical axis I;

g12 is the distance on the optical axis I from the display side surface 16 of the first lens 1 to the eye side surface 25 of the second lens 2, i.e. the air gap on the optical axis I from the first lens 1 to the second lens 2;

g23 is the distance on the optical axis I from the display side surface 26 of the second lens 2 to the eye side surface 35 of the third lens 3, i.e. the air gap on the optical axis I from the second lens 2 to the third lens 3;

G3D is the distance between the display side 36 of the third lens 3 and the display screen 99 on the optical axis I;

TTL is the distance from the eye side surface 15 of the first lens 1 to the display 99 on the optical axis I;

TL is the distance on the optical axis I from the eye side surface 15 of the first lens 1 to the display side surface 36 of the third lens 3;

ER is the exit pupil distance (Eye relief), which is the distance on the optical axis I from the viewer's pupil 0 to the Eye side 15 of the first lens 1;

SL is the system length, which is the distance from the pupil 0 of the observer to the display screen 99 on the optical axis I;

EPD is the exit pupil diameter D1(Eye pupil diameter, as shown in fig. 1) of the eyepiece optical system 10, which corresponds to the diameter of the pupil 0 of the observer, for example 3mm during the day and for example 7mm at night, as shown in fig. 1;

a diameter D2(image diameter, as shown in fig. 1) of a display image circle of the display screen 99 corresponding to the maximum viewing angle of the single eye of the viewer;

VD is a virtual image distance, that is, the distance between the magnified virtual image VV and the pupil 0 (i.e., exit pupil) of the observer, such as the virtual image distance VD shown in fig. 1, where the closest distance at which the eyes can clearly focus is called a photopic distance, and the photopic distance of young people is usually 250 mm;

ALT is the sum of lens thicknesses of the first lens 1 to the third lens 3 on the optical axis I, i.e., the sum of T1, T2, and T3;

AAG is the sum of two air gaps on the optical axis I of the first lens 1 to the third lens 3, i.e., the sum of G12 and G23;

r1 is the optically effective radius (half of clear aperture) of the eye side surface 15 of the first lens 1;

r2 is the optically effective radius of the eye side 25 of the second lens 2;

r3 is the optically effective radius of the eye side surface 35 of the third lens 3;

in addition, redefining:

f1 is the focal length of the first lens 1;

f2 is the focal length of the second lens 2;

f3 is the focal length of the third lens 3;

n1 is the refractive index of the first lens 1;

n2 is the refractive index of the second lens 2;

n3 is the refractive index of the third lens 3;

v1 is the Abbe number (Abbe number) of the first lens 1;

v2 is the abbe number of the second lens 2;

v3 is the abbe number of the third lens 3.

Referring to fig. 8a to D, fig. 8a to D are aberration diagrams of the eyepiece optical system of the first embodiment, and are aberration diagrams obtained by assuming that the light ray direction is reversely traced, i.e., a parallel imaging light ray passes through the pupil 0 and the eyepiece optical system 10 in sequence from the eye side a1 to the display screen 99 for focusing and imaging. In the present embodiment, the aberration expressions shown in the aberration diagrams determine the aberration expressions of the imaging light from the display screen 99 to the retina of the eye of the observer. That is, when the aberrations presented in the aberration diagrams are small, the aberrations of the image of the retina of the eye of the observer are also small, so that the observer can view an image with better imaging quality.

Specifically, fig. 8A illustrates longitudinal spherical aberration (longitudinal spherical aberration) of the first embodiment, fig. 8B and 8C illustrate field curvature (field curvature) aberration in the sagittal direction and field curvature aberration in the tangential direction of the first embodiment, respectively, and fig. 8D illustrates distortion aberration (distortion aberration) of the first embodiment. The longitudinal spherical aberration diagram of the first embodiment fig. 8A is simulated when the pupil radius (pupliradius) is 2.5000mm (i.e., when the exit pupil diameter EPD of the eyepiece optical system 10 is 5.000 mm). In addition, in the longitudinal spherical aberration diagram of the first embodiment shown in fig. 8A, the curves formed by each wavelength are very close and close to the middle, which means that the off-axis light beams with different heights of each wavelength are all concentrated near the imaging point, and the deviation of the curves of each wavelength is observed, and the deviation of the imaging points of the off-axis light beams with different heights is controlled within the range of ± 0.28mm, so that the present embodiment indeed improves the spherical aberration with the same wavelength, and in addition, the distances between the three representative wavelengths of 486 nm, 588 nm and 656 nm are very close, and the imaging positions representing the light beams with different wavelengths are very concentrated, so that the chromatic aberration is also improved.

In the two graphs of the field curvature aberrations of fig. 8B and 8C, the field curvature aberrations of the three representative wavelengths over the entire field of view fall within a range of ± 3.5mm, which shows that the eyepiece optical system 10 of the present first embodiment can effectively eliminate the aberrations. The distortion aberration diagram of fig. 8D shows that the distortion aberration of the first embodiment is maintained within a range of ± 30%, which indicates that the distortion aberration of the first embodiment meets the imaging quality requirement of the optical system, and thus the first embodiment can still provide better imaging quality under the condition that TTL is shortened to about 41.200mm compared with the conventional eyepiece optical system, so that the eyepiece optical system can be shortened under the condition that good optical performance is maintained, thereby realizing a thin product design. In addition, the eyepiece optical system 10 of the first embodiment has a large angle of view and can correct aberrations while maintaining good imaging quality.

Fig. 11 is a schematic view of an eyepiece optical system according to a second embodiment of the present invention, and fig. 12a to D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system according to the second embodiment. Referring to fig. 11, a second embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the difference between the two embodiments is as follows. The second embodiment is slightly different from the first embodiment in each optical data, aspherical coefficients, and parameters of the first lens 1 to the third lens 3. Furthermore, in the second embodiment, the circumferential region 154 of the eye side surface 15 of the first lens 1 is concave, and the circumferential region 364 of the display side surface 36 of the third lens 3 is concave. Note that, in fig. 11, the reference numerals of the optical axis region and the circumferential region similar to those of the first embodiment are omitted for clarity of illustration.

Detailed optical data of the eyepiece optical system 10 of the second embodiment is shown in fig. 13, and of the second embodimentThe eyepiece optical system 10 has an overall system focal length of 36.586mm and a half-eye viewing angle (ω)

The aperture value (Fno) is 7.317, the ICD is 50mm, and the TTL is 43.760 mm.

As shown in fig. 14, the aspheric coefficients of the target side surfaces 15, 25 and 35 and the display side surfaces 16, 26 and 36 of the first lens element 1 to the third lens element 3 of the second embodiment in formula (1) are shown.

Fig. 31 shows the relationship between the important parameters in the eyepiece optical system 10 of the second embodiment.

The longitudinal spherical aberration diagram of the present second embodiment fig. 12A is simulated when the pupil radius is 2.000mm (i.e., when the exit pupil diameter EPD of the eyepiece optical system 10 is 4.000 mm). In the longitudinal spherical aberration diagram of the second embodiment shown in fig. 12A, the deviation of the imaging points of the off-axis rays with different heights is controlled within ± 0.28 mm. In the two graphs of the field curvature aberration of fig. 12B and 12C, the field curvature aberration of the three representative wavelengths over the entire field of view falls within a range of ± 1.1 mm. The distortion aberration diagram of FIG. 12D shows that the distortion aberration of the second embodiment is maintained within a range of + -19%. Therefore, compared with the conventional eyepiece optical system, the second embodiment can still provide better imaging quality under the condition that the TTL is shortened to about 43.760 mm.

As can be seen from the above description, the advantages of the second embodiment over the first embodiment are: the curvature of field of the second embodiment is smaller than that of the first embodiment, and the distortion aberration of the second embodiment is smaller than that of the first embodiment. In addition, the thickness difference between the optical axis and the circumferential area of the lens of the second embodiment is smaller than that of the first embodiment, so that the second embodiment is easier to manufacture than the first embodiment, and thus the yield is higher.

Fig. 15 is a schematic view of an eyepiece optical system according to a third embodiment of the present invention, and fig. 16a to D are longitudinal spherical aberration and aberration diagrams of the eyepiece optical system according to the third embodiment. Referring to fig. 15, a third embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the main differences are as follows. The third embodiment is slightly different from the first embodiment in each optical data, aspherical coefficients, and parameters of the first lens 1 to the third lens 3. Further, in the third embodiment, the circumferential region 364 of the display side surface 36 of the third lens 3 is concave. Note here that, in fig. 15, the reference numerals of the optical axis region and the circumferential region similar to those of the first embodiment are omitted for clarity of illustration.

The detailed optical data of the eyepiece optical system 10 of the third embodiment is shown in fig. 17, and the overall system focal length of the eyepiece optical system 10 of the third embodiment is 37.170mm, and the half-eye view angle (ω) is

The aperture value (Fno) is 7.434, the ICD is 64mm, and the TTL is 46.580 mm.

As shown in fig. 18, the aspheric coefficients of the target side surfaces 15, 25 and 35 and the display side surfaces 16, 26 and 36 of the first lens element 1 to the third lens element 3 and the formula (1) are shown in the third embodiment.

Fig. 31 shows the relationship between the important parameters in the eyepiece optical system 10 of the third embodiment.

The longitudinal spherical aberration diagram 16A of the present third embodiment is simulated when the pupil radius is 2.5000mm (i.e., when the exit pupil diameter EPD of the eyepiece optical system 10 is 5.000 mm). In the longitudinal spherical aberration diagram of the third embodiment shown in fig. 16A, the deviation of the imaging points of the off-axis rays with different heights is controlled within ± 0.36 mm. In the two graphs of field curvature aberration of fig. 16B and 16C, the field curvature aberration of the three representative wavelengths over the entire field of view falls within a range of ± 1.6 mm. The distortion aberration diagram of FIG. 16D shows that the distortion aberration of the third embodiment is maintained within a range of + -15%. Therefore, the third embodiment can still provide better imaging quality under the condition that TTL is shortened to about 46.580mm compared with the conventional eyepiece optical system.

As can be seen from the above description, the third embodiment has the following advantages compared to the first embodiment: the half-angle of view of the third embodiment is larger than that of the first embodiment, the curvature of field of the third embodiment is smaller than that of the first embodiment, and the distortion aberration of the third embodiment is smaller than that of the first embodiment. In addition, the thickness difference between the optical axis and the circumferential area of the lens of the third embodiment is smaller than that of the first embodiment, so that the third embodiment is easier to manufacture than the first embodiment, and thus the yield is higher.

Fig. 19 is a schematic view of an eyepiece optical system of a fourth embodiment of the present invention, and a to D of fig. 20 are longitudinal spherical aberration and various aberration diagrams of the eyepiece optical system of the fourth embodiment. Referring to fig. 19, a fourth embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the main differences are as follows. The optical data, aspherical coefficients, and parameters of the first lens 1 to the third lens 3 of the fourth embodiment are more or less different from those of the first embodiment. Further, in the fourth embodiment, the circumferential region 364 of the display side surface 36 of the third lens 3 is concave. Note here that, in fig. 19, the reference numerals of the optical axis region and the circumferential region similar to those of the first embodiment are omitted for clarity of illustration.

Detailed optical data of the eyepiece optical system 10 is shown in fig. 21, and the eyepiece optical system 10 of the fourth embodiment has an overall system focal length of 40.517mm and a half-eye viewing angle (ω) ofThe aperture value (Fno) was 8.103, ICD 71mm, and TTL 50.290 mm.

As shown in fig. 22, the aspheric coefficients of the target side surfaces 15, 25 and 35 and the display side surfaces 16, 26 and 36 of the first lens element 1 to the third lens element 3 of the fourth embodiment in formula (1) are shown.

Fig. 31 shows the relationship between the important parameters in the eyepiece optical system 10 of the fourth embodiment.

The longitudinal spherical aberration diagram 20A of the present fourth embodiment is simulated when the pupil radius is 2.5000mm (i.e., when the exit pupil diameter EPD of the eyepiece optical system 10 is 5.000 mm). In the longitudinal spherical aberration diagram of the fourth embodiment, the deviation of the imaging points of the off-axis rays of different heights is controlled within ± 0.48mm in fig. 20A. In the two graphs of field curvature aberration of fig. 20B and 20C, the field curvature aberration of the three representative wavelengths over the entire field of view falls within a range of ± 2.4 mm. The distortion aberration diagram of FIG. 20D shows that the distortion aberration of the fourth embodiment is maintained within a range of + -13%. Therefore, compared with the conventional eyepiece optical system, the fourth embodiment can still provide better imaging quality under the condition that the TTL is shortened to about 50.290 mm.

As can be seen from the above description, the fourth embodiment has the following advantages compared to the first embodiment: the field curvature aberration of the fourth embodiment is smaller than that of the first embodiment, and the distortion aberration of the fourth embodiment is smaller than that of the first embodiment. In addition, the thickness difference between the optical axis and the circumferential area of the lens of the fourth embodiment is smaller than that of the first embodiment, so that the fourth embodiment is easier to manufacture than the first embodiment, and therefore, the yield is higher.

Fig. 23 is a schematic view of an eyepiece optical system of a fifth embodiment of the present invention, and a to D of fig. 24 are longitudinal spherical aberration and various aberration diagrams of the eyepiece optical system of the fifth embodiment. Referring to fig. 23, a fifth embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the main differences thereof are as follows. The optical data, aspherical coefficients, and parameters of the first lens 1 to the third lens 3 of the fifth embodiment are more or less different from those of the first embodiment. Further, in the fifth embodiment, the circumferential region 364 of the display side surface 36 of the third lens 3 is concave. Note here that, in order to clearly show the drawing, reference numerals of the optical axis region and the circumferential region similar to those of the first embodiment are omitted in fig. 23.

Detailed optical data of the eyepiece optical system 10 of the fifth embodiment is shown in fig. 25, and the eyepiece optical system 10 of the fifth embodiment has an overall system focal length of 38.314mm and a half-eye view angle (ω) of

The aperture value (Fno) is 7.663, the ICD is 56mm, and the TTL is 47.310 mm.

As shown in fig. 26, the aspheric coefficients of the target side surfaces 15, 25 and 35 and the display side surfaces 16, 26 and 36 of the first lens element 1 to the third lens element 3 of the fifth embodiment in formula (1) are shown.

Fig. 31 shows the relationship between important parameters in the eyepiece optical system 10 of the fifth embodiment.

The longitudinal spherical aberration diagram 24A of the present fifth embodiment is simulated at a pupil radius of 2.5000mm (i.e., at an exit pupil diameter EPD of the eyepiece optical system 10 of 5.000 mm). In the longitudinal spherical aberration diagram of the fifth embodiment shown in fig. 24A, the deviation of the imaging points of the off-axis rays with different heights is controlled within ± 0.42 mm. In the two graphs of the field curvature aberration of fig. 24B and 24C, the field curvature aberrations of the three representative wavelengths over the entire field of view fall within a range of ± 1.2 mm. The distortion aberration diagram of fig. 24D shows that the distortion aberration of the fifth embodiment is maintained within a range of ± 14%. Therefore, the fifth embodiment can still provide better imaging quality under the condition that TTL is shortened to about 47.310mm compared with the conventional eyepiece optical system.

As can be seen from the above description, the advantages of the fifth embodiment compared to the first embodiment are: the curvature of field of the fifth embodiment is smaller than that of the first embodiment, and the distortion aberration of the fifth embodiment is smaller than that of the first embodiment. In addition, the thickness difference between the optical axis and the circumferential area of the lens of the fifth embodiment is smaller than that of the first embodiment, so that the fifth embodiment is easier to manufacture than the first embodiment, and thus the yield is higher.

Fig. 27 is a schematic view of an eyepiece optical system of a sixth embodiment of the present invention, and a to D of fig. 28 are longitudinal spherical aberration and various aberration diagrams of the eyepiece optical system of the sixth embodiment. Referring to fig. 27, a sixth embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the main differences are as follows. The sixth embodiment is slightly different from the first embodiment in each optical data, aspherical coefficients, and parameters of the first lens 1 to the third lens 3. In addition, in the sixth embodiment, the optical axis region 361 of the display side surface 36 of the third lens 3 is convex, and the circumferential region 364 of the display side surface 36 of the third lens 3 is concave. Note here that, in fig. 27, the reference numerals of the optical axis region and the circumferential region similar to those of the first embodiment are omitted for clarity of illustration.

The detailed optical data of the eyepiece optical system 10 of the sixth embodiment is shown in fig. 29, and the overall system focal length of the eyepiece optical system 10 of the sixth embodiment is 25.781mm, and the half-eye view angle (ω) is

The aperture value (Fno) is 5.156, the ICD is 50mm, and the TTL is 41.320 mm.

As shown in fig. 30, the aspheric coefficients of the target side surfaces 15, 25 and 35 and the display side surfaces 16, 26 and 36 of the first lens element 1 to the third lens element 3 and the formula (1) are shown in the sixth embodiment.

Fig. 31 shows relationships among important parameters in the eyepiece optical system 10 according to the sixth embodiment.

The longitudinal spherical aberration diagram 28A of the present sixth embodiment is simulated when the pupil radius is 2.5000mm (i.e., when the exit pupil diameter EPD of the eyepiece optical system 10 is 5.000 mm). In the longitudinal spherical aberration diagram of the sixth embodiment shown in fig. 28A, the deviation of the imaging points of the off-axis rays with different heights is controlled within ± 0.6 mm. In the two graphs of field curvature aberration of fig. 28B and 28C, the field curvature aberration of the three representative wavelengths over the entire field of view falls within a range of ± 2.3 mm. The distortion aberration diagram of FIG. 28D shows that the distortion aberration of the sixth embodiment is maintained within a range of + -4.5%. Therefore, the sixth embodiment can still provide better imaging quality under the condition that TTL is shortened to about 41.320mm compared with the conventional eyepiece optical system.

As can be seen from the above description, the sixth embodiment has the following advantages compared to the first embodiment: the half-angle of view of the sixth embodiment is larger than that of the first embodiment, the curvature of field of the sixth embodiment is smaller than that of the first embodiment, and the distortion aberration of the sixth embodiment is smaller than that of the first embodiment.

With reference again to fig. 31. Fig. 31 is a table of optical parameters of the first to sixth embodiments, in which the units of the parameters in the rows "T1" to "EFL" are millimeters (mm).

When the relationship between the optical parameters in the eyepiece optical system 10 according to the embodiment of the present invention satisfies the following conditional expressions or at least one of the following designs, the designer can be assisted in designing an eyepiece optical system that has good optical performance, effectively reduced overall length, and is technically feasible:

the half-eye visual angle can be effectively increased and the imaging quality can be enhanced through mutual matching of the following designs: the design that the optical axis region 151 of the eye side surface 15 of the first lens element 1 is convex and the circumferential region 253 of the eye side surface 25 of the second lens element 2 is convex is beneficial to image magnification, and the design that the circumferential region 354 of the eye side surface 35 of the third lens element 3 is concave can effectively improve chromatic aberration and improve imaging quality.

Two, 250 millimeters (mm) is the photopic distance, which is the closest distance that the young eye can focus clearly, and the magnification of the system can be approximated to the ratio of 250mm to EFL, so eyepiece optical system 10 can satisfy 2.500 ≦ 250mm/EFL ≦ 25.000, which makes the magnification of the system not too large and increases the lens thickness and manufacturing difficulty, and the EFL not too long and affects the system length.

Thirdly, the eyepiece optical system 10 can satisfy at least one of the following conditional expressions, in order to maintain the thickness and the interval of each lens at an appropriate value, and avoid over-large parameters from being detrimental to the overall thinning of the eyepiece optical system 10, or avoid over-small parameters from affecting the assembly or increasing the difficulty in manufacturing:

G23/(G12+ T3) ≦ 2.000, preferably 0.600 ≦ G23/(G12+ T3) ≦ 2.000;

ALT/(T1+ G12+ T3) ≦ 1.700, preferably in the range of 1.100 ALT/(T1+ G12+ T3) ≦ 1.700;

T2/T3 ≦ 2.300, preferably 1.500 ≦ T2/T3 ≦ 2.300;

T1/T2 ≦ 1.400, preferably 0.700 ≦ T1/T2 ≦ 1.400;

T1/G23 ≦ 2.500, preferably 1.000 ≦ T1/G23 ≦ 2.500;

(AAG + T1)/T2 ≦ 2.300, preferably in the range of 1.500 ≦ (AAG + T1)/T2 ≦ 2.300;

ALT/T2 ≦ 3.300, preferably in the range of 2.200 ≦ ALT/T2 ≦ 3.300;

AAG/G23 ≦ 1.200, preferably in the range of 1.000 ≦ AAG/G23 ≦ 1.200;

(T1+ G12)/T2 ≦ 1.700, preferably in the range of 0.800 ≦ (T1+ G12)/T2 ≦ 1.700;

(T1+ G12+ T2+ G23)/T3 ≦ 6.400, preferably in the range of 3.900 ≦ T1+ G12+ T2+ G23)/T3 ≦ 6.400;

0.800 ≦ G3D/(T1+ AAG), preferably 0.800 ≦ G3D/(T1+ AAG) ≦ 2.200;

3.100 ≦ ALT/AAG, preferably in the range of 3.100 ≦ ALT/AAG ≦ 5.000;

1.300 ≦ (G12+ T2)/G23, preferably 1.300 ≦ (G12+ T2)/G23 ≦ 2.000.

Fourthly, the eyepiece optical system 10 can satisfy the following conditional expressions, in order to maintain a proper value for each of the system focal length and optical parameters, so as to avoid that any parameter is too large to be beneficial to the correction of the aberration of the entire eyepiece optical system 10, or avoid that any parameter is too small to affect the assembly or improve the difficulty in manufacturing:

EFL/G3D ≦ 2.000, preferably 1.400 ≦ EFL/G3D ≦ 2.000.

Fifthly, the eyepiece optical system 10 can satisfy at least one of the following conditional expressions, so that the ratio of the optical element parameter to the length of the eyepiece optical system 10 is maintained at a proper value, and the condition that the parameter is too small to be beneficial to production and manufacturing is avoided, or the condition that the parameter is too large to cause the length of the eyepiece optical system 10 to be too long is avoided:

TL/G3D ≦ 4.600, preferably 0.800 ≦ TL/G3D ≦ 4.600, more preferably 0.800 ≦ TL/G3D ≦ 2.500;

TTL/(T3+ G3D) ≦ 2.500, preferably 1.300 ≦ TTL/(T3+ G3D) ≦ 2.500;

TL/G23 ≦ 6.800, preferably in the range of 3.600 ≦ TL/G23 ≦ 6.800;

EFL/TL is 0.900 ≦ EFL/TL, preferably 0.900 ≦ EFL/TL ≦ 2.000;

1.800 ≦ TTL/ALT, preferably in the range 1.800 ≦ TTL/ALT ≦ 2.500;

1.400 ≦ TTL/TL, with a preferred range of 1.400 ≦ TTL/TL ≦ 2.500.

In view of the unpredictability of the optical system design, the above-mentioned conditions are preferably satisfied under the architecture of the present invention, so that the eyepiece optical system 10 of the present invention has a shorter system length, a larger half-eye viewing angle, a better imaging quality, or a better assembly yield, thereby improving the drawbacks of the prior art.

In addition, with respect to the exemplary limiting relations listed above, unequal numbers may also be optionally combined and applied to the implementation aspects of the present invention, and are not limited thereto. In addition to the above relation, the present invention can also design additional lens details such as concave-convex curved surface arrangement to enhance the control of system performance and/or resolution. It should be noted that these details need not be selectively incorporated into other embodiments of the present invention without conflict.

The ranges of values within the maximum and minimum values obtained from the combination ratios of the optical parameters disclosed in the embodiments of the present invention can be implemented.

In summary, the longitudinal spherical aberration, the field curvature aberration, and the distortion of the embodiments of the present invention all conform to the usage specifications. In addition, three representative wavelengths of 656 nm (red light), 588 nm (green light) and 486 nm (blue light) are all concentrated near the imaging point, and the deviation of each curve can show that the deviation of the imaging point of the off-axis light with different heights can be controlled, so that the spherical aberration, the aberration and the distortion suppression capability are good. Further referring to the imaging quality data, the distances between the three representative wavelengths 656 nm, 588 nm and 486 nm are also very close, which shows that the embodiments of the present invention have good concentration to different wavelengths of light and excellent dispersion suppression capability in various states, and thus it can be seen that the embodiments of the present invention have good optical performance. Therefore, the eyepiece optical system of the embodiment of the invention has the characteristics of lightness, thinness and large visual angle of eyes, and has good optical imaging quality.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.