WO2017181359A1 - Eyepiece optical system for near-eye display, and head-mounted display device - Google Patents

Abstract

An eyepiece optical system for a near-eye display, and a head-mounted display device. The eyepiece optical system comprises a first lens (L1), a reflection unit (P), a second lens (L2), and a third lens group (G3); the second lens and the third lens group have the same optical axis which is perpendicular to a micro image display (I); after the optical axis of the second lens and the third lens group is reflected by the reflection unit, said optical axis is identical to the optical axis of the first lens; the third lens group at least comprises a third lens (L3); the second lens and the third lens have aspheric optical profiles, and the first lens is the only lens disposed between the reflection unit and the observing side of human eye; the effective focal length of the first lens, f₁₁, the effective focal length of the second lens, f₂₁, the effective focal length of the third lens group, f₃, and the effective focal length of the eyepiece optical system, f_w, satisfy the relations 0.87 < f₁₁/f_w <3.8, f₂₁/f_w > 0.48, and f₃/f_w < -0.29. The present eyepiece optical system is compact in structure, small in size, and high in optical resolution, and can enable optimal visual experience for a head-mounted display device.

Description

Eyepiece optical system and head-mounted display device for near-eye display Technical field

The present invention relates to the field of optical technology, and more particularly to an eyepiece optical system and a head mounted display device for near-eye display.

Background technique

The head-mounted display device directs the video image light emitted by the micro-image display (for example, transmissive or reflective liquid crystal display, organic electroluminescent device, DMD device) to the user's pupil through optical technology, in the user's near eye The range realizes virtual and enlarged images, providing users with intuitive and visual images, videos and text information, which can be applied to outdoor, simulated driving, training, demonstration, teaching, training, medical, flight and other scenarios.

The eyepiece optical system is the core of the head mounted display device, which realizes the function of displaying a miniature image in front of the human eye to form a virtual enlarged image. The design of the eyepiece optical system directly affects the key factors such as the volume and visual experience of the head-mounted display device. Especially for an optical system applied to an optical non-see-through head-mounted display device, it is required to realize a large field of view in a small size and requires high optical resolution so that it can see enough picture details. At the same time, it is required to facilitate long-term viewing without visual fatigue. However, in the related art of the prior art head mounted display device, an optical system suitable for an optical non-see-through head mounted display device has not been found.

Patent US Pat. No. 7,180,675 B2 discloses an optical system of a viewfinder consisting of two positive and negative optical elements and a folding device. The eyepiece system only achieves a display effect of about 18° field of view, and the color difference is severe, C-line and F The -line color difference is greater than 0.5 mm, which cannot achieve a higher resolution optical display effect, and thus cannot be applied to an optical non-see-through head-mounted display device.

Patent US Pat. No. 8,531,774 B2 discloses an optical system of a viewfinder comprising two positive lenses, a negative lens and a reflecting unit, and two positive and negative lenses are placed between the observer's eye and the reflecting unit, although the optical system can realize 26 The angle of view of °, but its exit position is shorter (<11mm), and the size along the line of sight is larger. For example, when applied to an optical non-see-through head-mounted display device, the comfortable wearing requirements of the product cannot be satisfied, and at the same time, the optical astigmatic aberration remains large, and the edge field of view image quality is difficult to achieve high-resolution optical effects, which is disadvantageous for long-term comfort. Visual experience.

Summary of the invention

The technical problem to be solved by the present invention is to provide an eyepiece optical system and a head mounted display device for near-eye display in view of the above-described drawbacks of the prior art.

The technical solution adopted by the present invention to solve the technical problem thereof is:

Constructing an eyepiece optical system for near-eye display, comprising a first lens, a reflection unit, a second lens, and a third lens group arranged coaxially in the optical axis direction from the human eye observation side to the micro image display device side; The optical axes of the second lens and the third lens group are coaxial and perpendicular to the micro image display; the optical axes of the second lens and the third lens group are reflected by the reflection unit and are coaxial with the optical axis of the first lens; The third lens group includes at least a third lens;

The second lens and the third lens are optical aspherical surfaces; the first lens is a unique lens disposed between the reflective unit and the viewing side of the human eye; an effective focal length f of the first lens _11, the effective focal length of the second lens is f _21, the effective focal length f _w of the effective focal length of the third lens group is f ₃ and the eyepiece optical system satisfies the following relation (1), (4) and (5) :

0.87<f ₁₁ /f _w <3.8 (1);

f ₂₁ /f _w >0.48 (4);

f ₃ /f _w <-0.29 (5).

In the eyepiece optical system of the present invention, the third lens group is composed of two optical lenses, wherein the lens adjacent to the micro image display is a fourth lens.

In the eyepiece optical system of the present invention, the optical surface of the first lens near the viewing side of the human eye is convex toward the viewing direction of the human eye.

In the eyepiece optical system of the present invention, the first lens is an aspherical lens.

The eyepiece optical system of the present invention, wherein the reflecting unit is a sheet having a reflective function, the sheet comprising a base layer and a reflective coating layer, the base layer being glass, plastic or other inorganic material.

In the eyepiece optical system of the present invention, the reflecting unit is an optical prism.

In the eyepiece optical system of the present invention, the optical surface of the first lens adjacent to the reflecting unit side is a flat surface.

In the eyepiece optical system of the present invention, the optical surface of the second lens adjacent to the reflecting unit side is a flat surface.

The eyepiece optical system of the present invention, wherein: the fourth lens is adjacent to the optical surface of the miniature image display concave to the miniature image display.

The eyepiece optical system of the present invention, wherein: an optical plane of the first lens is glued to an adjacent plane of the optical prism, or an optical plane of the second lens is glued to an adjacent plane of the optical prism, Or the first lens, the second lens and the optical prism are glued together.

In the eyepiece optical system of the present invention, the turning angle θ of the reflecting unit to the optical axis of the eyepiece optical system satisfies the following relation (6):

θ = 90° (6).

In the eyepiece optical system of the present invention, the effective focal length f _{11 of} the first lens further satisfies the following relation (7):

1.10<f ₁ /f _w <2.45 (7).

In the eyepiece optical system of the present invention, the effective focal length f _{21 of} the second lens and the effective focal length f _{3 of} the third lens group further satisfy the following relations (10) and (11):

0.50<f ₂₁ /f _w <41.3 (10);

-5.9 <f ₃ /f _w <-0.35 (11).

In the eyepiece optical system of the present invention, the material of the first lens, the second lens and the third lens is a glass material or a plastic material.

In the eyepiece optical system of the present invention, a PBS prism or a sheet type PBS is provided between the third lens group and the micro image display in the optical axis direction.

The present invention also provides another head mounted display device comprising a miniature image display unit and an eyepiece, the eyepiece being located between the human eye and the miniature image display unit, wherein: the eyepiece is any of the foregoing Eyepiece optical system.

The head mounted display device of the present invention, wherein the micro image display device is an organic electroluminescence light emitting device or a transmissive liquid crystal display or a reflective liquid crystal display.

The head mounted display device of the present invention, wherein the head mounted display device adjusts the diopter by adjusting a distance between the microdisplay and the eyepiece optical system in the optical axis direction.

The head mounted display device of the present invention, wherein the head mounted display device is a binocular head mounted display device comprising two identical eyepiece optical systems.

The invention has the advantages that the eyepiece optical system has the advantages of compact structure, small size, high optical resolution, and the like, and the diameter of the exit pupil is larger than that of the general eyepiece; the eyepiece optical system can be used with a spherical lens and an aspheric lens, optical plastic and optical. The use of glass in combination, in order to reduce the manufacturing cost and product weight, the system aberration is greatly eliminated, especially the optical indicators such as low distortion, low chromatic aberration, low field curvature and low astigmatism are realized, so that the observer can Through the eyepiece optical system of the invention, a full-frame high-definition, distortion-free, uniform image quality is obtained to achieve an optimal visual experience.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the prior art, the present invention will be further described in conjunction with the accompanying drawings and embodiments. For ordinary technicians, other drawings can be obtained based on these drawings without any creative work:

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

Figure 2 is a dot-column diagram of an eyepiece optical system according to a first embodiment of the present invention;

3a is a field curvature diagram of an eyepiece optical system according to a first embodiment of the present invention, and FIG. 3b is a distortion diagram of an eyepiece optical system according to a first embodiment of the present invention;

Figure 4 is a light path diagram of an eyepiece optical system according to a second embodiment of the present invention;

Figure 5 is a dot-column diagram of an eyepiece optical system according to a second embodiment of the present invention;

Figure 6a is a field curvature diagram of an eyepiece optical system according to a second embodiment of the present invention, and Figure 6b is a distortion diagram of an eyepiece optical system according to a second embodiment of the present invention;

Figure 7 is a light path diagram of an eyepiece optical system according to a third embodiment of the present invention;

Figure 8 is a dot-column diagram of an eyepiece optical system according to a third embodiment of the present invention;

Figure 9a is a field curvature diagram of an eyepiece optical system according to a third embodiment of the present invention, and Figure 9b is an eyepiece of a third embodiment of the present invention. Optical system distortion curve;

Figure 10 is a light path diagram of an eyepiece optical system according to a fourth embodiment of the present invention;

Figure 11 is a dot-column diagram of an eyepiece optical system according to a fourth embodiment of the present invention;

Figure 12a is a field curvature diagram of an eyepiece optical system according to a fourth embodiment of the present invention, and Figure 12b is a distortion diagram of the eyepiece optical system of the fourth embodiment of the present invention;

Figure 13 is a light path diagram of an eyepiece optical system according to a fifth embodiment of the present invention;

Figure 14 is a dot-column diagram of an eyepiece optical system according to a fifth embodiment of the present invention;

Fig. 15a is a field curvature diagram of an eyepiece optical system according to a fifth embodiment of the present invention, and Fig. 15b is a distortion diagram of an eyepiece optical system according to a fifth embodiment of the present invention.

detailed description

The present invention will be described in detail with reference to the embodiments of the present invention. Not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any inventive effort are within the scope of the present invention.

An eyepiece optical system for near-eye display according to an embodiment of the present invention includes a first lens, a reflection unit, a second lens, and a third lens group which are arranged coaxially in the optical axis direction from the human eye observation side to the micro image display device side The optical axes of the second lens and the third lens group are coaxial and perpendicular to the micro image display; the optical axes of the second lens and the third lens group are reflected by the reflection unit and are coaxial with the optical axis of the first lens; The lens group includes at least a third lens; the second lens and the third lens are optical aspherical surface type; the first lens is a unique lens disposed between the reflective unit and the viewing side of the human eye; the effective focal length f _{11 of the} first lens and The effective focal length fw of the eyepiece optical system satisfies the following relation (1):

0.87<f ₁₁ /f _w <3.8 (1).

Wherein, the value of f ₁₁ /f _w may be 1.05, 2.66, 1.21, 3.80, 1.35, 0.87, 1.39, 1.47, 1.21, 1.54, 1.45, 1.88, 1.29, 1.25, 1.20, 1.14, 1.21, 1.15, 1.17, 1.25, 1.13, 1.67.

Further, the effective focal length f _w of the second lens effective focal length f of the lens group _21, a third effective focal length f of the optical system and the _{eyepiece. 3,} satisfy the following relationships (4) and (5):

f ₂₁ /f _w >0.48 (4);

f ₃ /f _w <-0.29 (5).

Where f ₂₁ /f _w may be 0.48, 41.30, 0.50, 0.56, 1.12, 0.56; f ₃ /f _w may be -7.48, -3.21, -0.29, -5.90, -0.34, - 0.40, -0.69, -0.43.

In the above relational expressions (4) and (5), the range of values of f ₂₁ /f _w and f ₃ /f _w is closely related to the correction of the system aberration, the difficulty of processing the optical element, and the sensitivity of the optical component assembly deviation. The system aberrations are sufficiently corrected to achieve superior optical effects and improve the processability of the optical components in the system.

As shown in FIG. 1, the first lens L1, the prism P, the second lens L2, and the third lens L3 which are arranged coaxially in the optical axis direction from the human eye observation side to the micro image display device side are arranged. The optical surface number near the side of the pupil E is 1, and so on. Push (2, 3, 4, 5, 6, 7, 8 from left to right), the surface of the display I is 13, and the reflective surface of the reflector is R. The light emitted from the micro image display passes through the third lens, the second lens, the reflection unit, and the first lens, and then enters the human eye.

In the above embodiment, since a single lens having a focal length satisfying the above relation (1) is provided between the reflecting unit and the human eye observation side, not only the overall size of the eyepiece optical system can be reduced, but The maximum viewing angle can be achieved under the same size, and when the reflecting unit is an optical prism, the bonding or integral molding with the prism can be realized, which greatly reduces the difficulty of production assembly and the complexity of structural design.

At the same time, the distortion of the system is well corrected by using the second lens and the third lens of the optical aspherical surface type.

Compared with the patented technical solutions of US Pat. No. 7,180,675 B2 and US Pat. No. 8,531,774 B2, the eyepiece optical system of the present invention is designed by a combination of a first positive lens and a reflecting unit, while increasing the effective field of view of the system, to a great extent Controlling the size of the system, through the matching design of the second lens and the third lens group, and the design application of the optical aspherical surface type, the aberration of the system is well corrected, and an effective field of view of 24° to 30° can be realized. At the same time, the full-frame C-line and F-line have a color difference of less than 0.08mm, and at the same time realize optical performance such as compact structure, large field of view, high optical resolution and low distortion, which is conducive to long-term comfortable viewing.

In a further embodiment of the eyepiece optical system, the optical surface of the second lens adjacent to the side of the micro image display is concave toward the micro image display, which can further reduce the size of the eyepiece optical system, improve the image quality, correct distortion, and improve the image of the system. Aberrations such as scatter and field curvature are beneficial to the high-resolution optical effect of the eyepiece system to achieve uniform image quality.

In a further eyepiece optical system embodiment, the third lens group is composed of two optical lenses, further comprising a fourth lens adjacent to the miniature image display, and the fourth lens is used to better correct field curvature and astigmatism, which is advantageous for Achieve greater field of view and higher optical resolution.

Preferably, in the above embodiment of the eyepiece optical system, the fourth lens is adjacent to the optical surface of the micro image display concave to the micro image display, effectively reducing the overall size of the eyepiece optical system, improving the image quality, correcting the distortion, and improving the system. The aberrations such as astigmatism and field curvature are beneficial to the high-resolution optical effect of the eyepiece system to achieve uniform image quality.

In a further embodiment of the eyepiece optical system, the optical surface of the first lens near the viewing side of the human eye is convex toward the viewing direction of the human eye, which is more advantageous for reducing the size of the optical system, so that the maximum viewing angle can be achieved under the same size. The image quality, improving the astigmatism and field curvature of the system, is conducive to the high-resolution optical effect of the eyepiece system to achieve uniform image quality.

In a further eyepiece optical system embodiment, the first lens is an aspherical lens. The expression of the aspheric surface is of the formula (a):

Where z is the vector height of the optical surface, c is the curvature at the aspherical vertex, k is the aspherical coefficient, α2, 4, 6... are the coefficients of each order, and r is the distance coordinate of the point on the curved surface to the optical axis of the lens system.

In the above embodiment of the eyepiece optical system, the reflecting unit is a sheet having a reflecting function, and the sheet comprises a base layer and a reflective coating layer, and the base layer is glass, plastic or other inorganic material, which can reduce the manufacturing cost and reduce the system. Total weight.

In the above embodiment of the eyepiece optical system, the reflecting unit adopts an optical prism, which can better correct the aberration performance of the optical system.

Preferably, in the above embodiment of the eyepiece optical system, the optical surface of the first lens near the reflection unit side is a plane; and the optical surface of the second lens near the reflection unit side is a plane.

Preferably, in the above embodiment of the eyepiece optical system, the optical plane of the first lens is glued to the adjacent plane of the optical prism, or the optical plane of the second lens is glued to the adjacent plane of the optical prism, or the first lens and the second lens And optical prisms are glued together.

In the above embodiment of the eyepiece optical system, the turning angle θ of the reflecting unit to the optical axis of the eyepiece optical system may be any angle of 0-180°. Preferably, the turning angle θ of the reflecting unit to the optical axis of the eyepiece optical system satisfies the following relation (6):

θ = 90° (6).

Preferably, in the above embodiment of the eyepiece optical system, the effective focal length f _{11 of the} first lens further satisfies the following relation (7):

1.10<f ₁₁ /f _w <2.45 (7).

Wherein, the value of f ₁₁ /f _w may be 1.10, 1.22, 1.36, 0.89, 1.49, 1.47, 1.21, 1.54, 1.45, 1.88, 1.29, 1.25, 1.20, 1.14, 1.67, 2.10, 2.21, 2.32, 2.45.

In the above relation (7), the range of f ₁₁ /f _w is closely related to the correction of the system aberration, the difficulty of processing the optical component, and the sensitivity of the optical component assembly deviation, so that the system aberration is sufficiently corrected, thereby realizing High quality optical effects and improved processability of optical components in the system.

In the above relations (10) and (11), the range of values of f ₂₁ /f _w and f ₃ /f _w is closely related to the correction of system aberration, the difficulty of processing the optical element, and the sensitivity of optical component assembly deviation. The system aberrations are sufficiently corrected to achieve superior optical effects and improve the processability of the optical components in the system.

Preferably, in the above embodiment of the eyepiece optical system, the effective focal length f _{21 of the} second lens and the effective focal length f _{3 of the} third lens group further satisfy the following relations (10) and (11):

0.50<f ₂₁ /f _w <41.3 (10);

_{-5.9 <f 3 / f w <} -0.35 (11).

Wherein f ₂₁ /f _w may be 0.50, 0.67, 0.87, 0.94, 1.23, 1.57, 2.39, 3.54, 12.34, 41.3; f ₃ /f _w may be -5.9, -4.35, -3.10 , -2.57, -1.35, -0.35.

In the above relations (10) and (11), the range of values of f ₂₁ /f _w and f ₃ /f _w is closely related to the correction of system aberration, the difficulty of processing the optical element, and the sensitivity of optical component assembly deviation. The system aberrations are sufficiently corrected to achieve superior optical effects and improve the processability of the optical components in the system.

Preferably, in the above embodiment of the eyepiece optical system, the materials of the first lens, the second lens and the third lens are glass materials or plastic materials.

In a further embodiment, when the micro image display uses a liquid crystal on silicon (LCOS) display, the third lens group and the micro image display have a PBS (Polarization Beam) along the optical axis direction. Splitter) A prism or sheet PBS that is used in conjunction with an LED source to provide illumination to the LCOS display.

The invention will now be further described with reference to the drawings and specific embodiments. In the optical path diagrams of the following embodiments, the light emitted from the micro image display passes through the third lens, the second lens, the reflection unit, and the first lens in order, and then enters the human eye. The aperture E can be used to image the eyepiece optical system, which is a virtual light-emitting aperture. When the pupil of the human eye is in the pupil position, the best imaging effect can be observed. The dot-column diagram provided in the following embodiments reflects the geometry of the optical system imaging, ignoring the diffraction effect, and specifying the field of view, the speckle pattern formed by the focused wavelength ray focusing image plane section, and can include multiple fields of view and multiple wavelengths simultaneously. The light. Therefore, the intensity of the optical system imaging quality can be directly measured by the intensity and shape of the speckle pattern, and the chromatic aberration of the optical system can be visually measured by the degree of dislocation of the different wavelength dispersion spots in the dot pattern. The smaller the Root Meam Square radius (root mean square radius), the higher the imaging quality of the optical system.

Embodiment 1: A schematic diagram of an optical path structure of an eyepiece optical system, as shown in FIG. 1, includes a first lens L1, a prism P, and a second lens L2 which are arranged coaxially in the optical axis direction from the human eye observation side to the micro image display device side. The third lens L3. The optical surface number near the side of the pupil E is 1, and so on (2, 3, 4, 5, 6, 7, 8 from left to right), the surface of the display I is 13, and the reflecting surface of the reflecting unit is R. . The first lens L1 is a plano-convex positive lens, the second lens L2 is a biconvex positive lens, and the third lens L3 is a biconcave negative lens. The optical structure can sufficiently correct aberrations such as distortion, chromatic aberration and curvature of field of the system, and provide sufficient forward power with a small angle of field, and the angle of view reaches 28°.

Table 1 Example 1 optical system parameter list

FIG. 2 is a schematic diagram of a point-and-column diagram of the eyepiece optical system of the present embodiment. It can be seen that the diffused spot radius of each field of view light in the image plane (display device I) is small and uniform, and different wavelengths of light are in the same The degree of dislocation of the diffuse spot formed by the field of view focusing is low, the aberration of the optical system is well corrected, and the whole can be observed through the eyepiece optical system. Uniform, high optical performance display image.

3(a) and 3(b) respectively show field curvature and distortion curves of the eyepiece according to the present embodiment, which characterize the large field of view and high image quality of the optical system of the present embodiment.

Embodiment 2: Schematic diagram of the optical path structure of the eyepiece optical system, as shown in FIG. 4, includes a first lens L1, a prism P, and a second lens L2 which are arranged coaxially in the optical axis direction from the human eye observation side to the micro image display device side. The third lens L3. The optical surface number near the side of the pupil E is 1, and so on (2, 3, 4, 5, 6, 7, 8 from left to right), the surface of the display I is 13, and the reflecting surface of the reflecting unit is R. . The first lens L1 is a plano-convex positive lens, the second lens L2 is a plano-convex positive lens, and the third lens L3 is a biconcave-shaped negative lens, wherein the first lens L1 is cemented with the prism P, and the prism P and The second lens L2 is glued. The optical structure can adequately correct aberrations, chromatic aberrations, and curvature of field of the system, and provide sufficient forward power with a small field of view, and the field of view angle reaches 26°.

Table 2 Example 2 optical system parameter list

FIG. 5 is a schematic diagram of a point-and-column diagram of the eyepiece optical system of the present embodiment. It can be seen that the diffuse spot radius of each field of view light in the image plane (display device I) is small and uniform, and different wavelengths of light are in the same The degree of dislocation of the diffuse formed by the field of view is low, the aberration of the optical system is well corrected, and the overall uniform and high optical performance display image can be observed through the eyepiece optical system.

6(a) and 6(b) respectively show field curvature and distortion curves of the eyepiece according to the present embodiment, which characterize the large field of view and high image quality of the optical system of the present embodiment.

Embodiment 3: Schematic diagram of the optical path structure of the eyepiece optical system, as shown in FIG. 7, includes a first lens L1, a prism P, and a second lens L2 which are arranged coaxially in the optical axis direction from the human eye observation side to the micro image display device side. The third lens L3 and the fourth lens L4. The optical surface number near the side of the pupil E is 1, and so on (2, 3, 4, 5, 6, 7, 8, 9, 10 from left to right), the surface of the display I is 13, the reflection unit The reflecting surface is R. The first lens L1 is a flat convex shape The positive lens, the second lens L2 is a biconvex positive lens, the third lens L3 is a biconcave negative lens, and the fourth lens L4 is a meniscus negative lens. The optical structure can sufficiently correct aberrations such as distortion, chromatic aberration and field curvature of the system, and provide sufficient forward power with a small angle of field, and the angle of view reaches 29°.

Table 3 Example 3 optical system parameter list

FIG. 8 is a schematic diagram of a point-and-column diagram of the eyepiece optical system of the present embodiment. It can be seen that the diffuse spot radius of each field of view light in the image plane (display device I) is small and uniform, and different wavelengths of light are in the same The degree of dislocation of the diffuse formed by the field of view is low, the aberration of the optical system is well corrected, and the overall uniform and high optical performance display image can be observed through the eyepiece optical system.

9(a) and 9(b) respectively show field curvature and distortion curves of the eyepiece according to the present embodiment, which characterize the large field of view and high image quality of the optical system of the present embodiment.

Embodiment 4: Schematic diagram of the optical path structure of the eyepiece optical system, as shown in FIG. 10, includes a first lens L1, a prism P, and a second lens L2 which are arranged coaxially in the optical axis direction from the human eye observation side to the micro image display device side. The third lens L3 and the fourth lens L4. The optical surface number near the side of the pupil E is 1, and so on (2, 3, 4, 5, 6, 7, 8, 9, 10 from left to right), the surface of the display I is 13, the reflection unit The reflecting surface is R. The first lens L1 is a plano-convex positive lens, the second lens L2 is a meniscus-shaped positive lens, the third lens L3 is a biconvex positive lens, and the fourth lens L4 is a biconcave negative lens. The optical structure adequately corrects aberrations, chromatic aberrations, and curvature of field of the system, and provides sufficient forward power with a small field of view, with an angle of view of 29°.

Table 4 Example 4 optical system parameter list

FIG. 11 is a schematic diagram of a point-and-column diagram of the eyepiece optical system of the present embodiment. It can be seen that the diffuse spot radius of each field of view light in the image plane (display device I) is small and uniform, and different wavelengths of light are in the same The degree of dislocation of the diffuse formed by the field of view is low, the aberration of the optical system is well corrected, and the overall uniform and high optical performance display image can be observed through the eyepiece optical system.

12(a) and 12(b) respectively show field curvature and distortion curves of the eyepiece according to the present embodiment, which characterize the large field of view and high image quality of the optical system of the present embodiment.

Embodiment 5: Schematic diagram of the optical path structure of the eyepiece optical system, as shown in FIG. 13, includes a first lens L1, a prism P, and a second lens L2 which are arranged coaxially in the optical axis direction from the human eye observation side to the micro image display device side. The third lens L3 and the fourth lens L4. The optical surface number near the side of the pupil E is 1, and so on (2, 3, 4, 5, 6, 7, 8, 9, 10 from left to right), the surface of the display I is 13, the reflection unit The reflecting surface is R. The first lens L1 is a plano-convex positive lens, the second lens L2 is a biconvex positive lens, the third lens L3 is a biconcave negative lens, and the fourth lens L4 is a meniscus positive lens. The optical structure can sufficiently correct aberrations, chromatic aberrations, field curvatures and the like of the system, and provide sufficient forward power with a small field of view, and the field of view angle reaches 29°.

Table 5 Example 5 optical system parameter list

FIG. 14 is a schematic diagram of a point-and-column diagram of the eyepiece optical system of the present embodiment. It can be seen that the diffuse spot radius of each field of view light in the image plane (display device I) is small and uniform, and different wavelengths of light are in the same The degree of dislocation of the diffuse formed by the field of view is low, the aberration of the optical system is well corrected, and the overall uniform and high optical performance display image can be observed through the eyepiece optical system.

15(a) and 15(b) respectively show field curvature and distortion curves of the eyepiece according to the present embodiment, which characterize the large field of view and high image quality of the optical system of the present embodiment.

The data of the above embodiments 1-5 meet the parameter requirements recorded in the invention, and the results are as shown in Table 6 below:

Table 6 Example 1-5 optical system parameter values

	f 11 /f w	f 21 /f w	f 3 /f w	f 31 /f w
Example 1	1.13	0.56	-0.43	-0.43
Example 2	0.87	0.61	-0.36	-0.36
Example 3	1.15	0.50	-0.34	-0.47
Example 4	1.21	41.30	-5.90	0.62
Example 5	1.17	0.56	-0.40	-0.38

In a further embodiment 6-10, an optical system having the parameters shown in Table 7 below is provided:

Table 7 Example 6-10 optical system parameter values

	f 11 /f w	f 21 /f w	f 3 /f w	f 31 /f w
Example 6	3.80	0.48	-0.33	-0.40
Example 7	2.12	0.53	-0.29	0.72
Example 8	1.72	1.05	-0.98	-0.72
Example 9	1.25	3.88	-1.65	-0.58
Example 10	1.32	0.66	-0.47	-0.72

In another embodiment of the present invention, there is also provided another head mounted display device comprising a miniature image display unit and an eyepiece, the eyepiece being located between the human eye and the miniature image display unit, wherein: the eyepiece is implemented in any of the foregoing The eyepiece optical system described in the example.

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

Preferably, the head mounted display device adjusts the diopter by adjusting the distance between the microdisplay and the eyepiece optical system in the optical axis direction.

Preferably, the head mounted display device is a binocular head mounted display device comprising two identical eyepiece optical systems as described above.

In summary, the eyepiece optical system of the above embodiments of the present invention has the advantages of compact structure, small size, high optical resolution, and the like, and the diameter of the exit pupil is larger than that of the general eyepiece; the eyepiece optical system can be used with a spherical lens and an aspherical lens. The combination of optical plastic and optical glass enables the systematic elimination of system aberrations on the basis of reducing manufacturing cost and product weight, especially at the same time achieving optical indicators such as low distortion, low chromatic aberration, low field curvature, and low astigmatism. The observer can use the eyepiece optical system of the present invention to view a full-frame high-definition, distortion-free, uniform image with a uniform image to achieve an optimal visual experience.

It is to be understood that those skilled in the art will be able to make modifications and changes in accordance with the above description, and all such modifications and variations are intended to be included within the scope of the appended claims.

Claims (19)

1. An eyepiece optical system for near-eye display, comprising: a first lens, a reflection unit, a second lens, and a third lens arranged coaxially in the optical axis direction from the human eye observation side to the micro image display device side The optical axes of the second lens and the third lens group are coaxial and perpendicular to the micro image display; the optical axes of the second lens and the third lens group are reflected by the reflective unit and the optical axis of the first lens Coaxial; the third lens group includes at least a third lens;

   The second lens and the third lens are optical aspherical surfaces, and the first lens is a unique lens disposed between the reflective unit and the viewing side of the human eye;

   An effective focal length f ₁₁ of the first lens, an effective focal length f ₂₁ of the second lens, an effective focal length f _{3 of} the third lens group, and an effective focal length f _{w of} the eyepiece optical system satisfy the following relationship (1) ), (4) and (5):

   0.87<f ₁₁ /f _w <3.8 (1);

   f ₂₁ /f _w >0.48 (4);

   _{f 3 / f w <-0.29 (} 5).
2. The eyepiece optical system according to claim 1, wherein said third lens group further comprises a fourth lens adjacent to the micro image display.
3. The eyepiece optical system according to claim 1, wherein the optical surface of the first lens near the viewing side of the human eye is convex toward the human eye.
4. The eyepiece optical system according to claim 1, wherein said first lens is an aspherical lens.
5. The eyepiece optical system according to claim 1, wherein said reflecting unit is a sheet having a reflecting function, said sheet comprising a base layer and a reflective coating layer, said base layer being glass, plastic or other inorganic material.
6. The eyepiece optical system according to claim 1, wherein said reflecting unit is an optical prism.
7. The eyepiece optical system according to claim 1, wherein the optical surface of the first lens adjacent to the reflecting unit side is a flat surface.
8. The eyepiece optical system according to claim 1, wherein the optical surface of the second lens adjacent to the reflecting unit side is a flat surface.
9. The eyepiece optical system according to claim 2, wherein said fourth lens is adjacent to the optical surface of the micro image display concave to the micro image display.
10. The eyepiece optical system according to claim 6, 7 or 8, wherein an optical plane of said first lens is glued to an adjacent plane of said optical prism, or an optical plane of said second lens is said Adjacent optical prism The plane is glued, or the first lens, the second lens and the optical prism are glued together.
11. The eyepiece optical system according to claim 5 or 6, wherein the turning angle θ of the reflecting unit to the optical axis of the eyepiece optical system satisfies the following relation (6):

    θ = 90° (6).
12. The eyepiece optical system according to claim 1, wherein an effective focal length f _{11 of} said first lens further satisfies the following relation (7):

    1.10<f ₁₁ /f _w <2.45 (7).
13. The eyepiece optical system according to claim 1, wherein an effective focal length f _{21 of} said second lens and an effective focal length f _{3 of} said third lens group further satisfy the following relational expressions (10) and (11):

    0.50<f ₂₁ /f _w <41.3 (10);

    -5.9 <f ₃ /f _w <-0.35 (11).
14. The eyepiece optical system according to claim 1, wherein the material of the first lens, the second lens, and the third lens is a glass material or a plastic material.
15. The eyepiece optical system according to claim 1, wherein a PBS prism or a sheet type PBS is provided between the third lens group and the micro image display in the optical axis direction.
16. A head mounted display device comprising a miniature image display unit and an eyepiece, the eyepiece being located between the human eye and the miniature image display unit, wherein the eyepiece is any one of claims 1 to Eyepiece optical system.
17. The head mounted display device according to claim 16, wherein the micro image display device is an organic electroluminescence light emitting device or a transmissive liquid crystal display or a reflective liquid crystal display.
18. The head mounted display device according to claim 17, wherein the head mounted display device adjusts the diopter by adjusting a distance between the microdisplay and the eyepiece optical system in the optical axis direction.
19. A head mounted display device according to claim 18, wherein said head mounted display device is a binocular head mounted display device comprising two identical eyepiece optical systems.

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