Head-mounted optical system

Abstract

The utility model belongs to the display imaging field, and specifically relates to a head-mounted optical system comprising a light source assembly comprising a first light source and a second light source; the first spectroscope is arranged between the first light source and the second light source, and two surfaces of the first spectroscope are respectively opposite to the first light source and the second light source; the reflecting assembly comprises a first reflecting mirror which is arranged opposite to the first spectroscope; the second reflecting mirror is arranged opposite to the first reflecting mirror; the third reflecting mirror is arranged opposite to the second reflecting mirror; light emitted by the first light source is transmitted by the first spectroscope to enter the first reflecting mirror, and is reflected by the first reflecting mirror, the second reflecting mirror and the third reflecting mirror in sequence to be emitted to the exit pupil, so that a first focal plane with a first focal plane depth is formed; light emitted by the second light source is reflected by the first spectroscope, then enters the first reflector, and is emitted to the exit pupil after being reflected by the first reflector, the second reflector and the third reflector in sequence, so that a second focal plane with a second focal plane depth is formed. Through the setting, the use experience is improved.

Description

Technical Field

[0001] The utility model belongs to the field of display imaging, and in particular relates to a head-mounted optical system. Background Art

[0002] In the prior art, near-eye display technologies include desktop devices and wearable devices. Wearable devices are usually worn on the head and opposite to the eyes, in the shape of glasses, so the size of the wearable device is limited, the internal optical path structure is compact, and the overall weight is relatively light.

[0003] The optical path forming the wearable device has different forms, including a BB (Birdbath) optical path, or an optical path formed by a free-form surface prism, or an optical path formed by a lens group.

[0004] However, the optical system formed by the above is relatively heavy, which will shorten the viewing time to a certain extent and provide a poor user experience. In addition, there is dispersion in the process of light propagation, which makes the final image quality poor. Utility Model Content

[0005] The present invention is proposed based on the above-mentioned requirements of the prior art, and the technical problem to be solved by the present invention is to provide a head-mounted optical system to enhance the user experience.

[0006] In order to solve the above problems, the technical solution provided by the utility model includes:

[0007] A head-mounted optical system is provided, comprising: a light source assembly, comprising a first light source and a second light source; a first beam splitter, arranged between the first light source and the second light source, and two sides of the first beam splitter are arranged opposite to the first light source and the second light source respectively; a reflection assembly, comprising a first reflector, arranged opposite to the first beam splitter; a second reflector, arranged opposite to the first reflector; and a third reflector, arranged opposite to the second reflector; light emitted by the first light source is incident on the first reflector after being transmitted through the first beam splitter, and is reflected by the first reflector, the second reflector and the third reflector in sequence and emitted toward an exit pupil, forming a first focal plane with a first focal plane depth; light emitted by the second light source is incident on the first reflector after being reflected by the first beam splitter, and is reflected by the first reflector, the second reflector and the third reflector in sequence and emitted toward the exit pupil, forming a second focal plane with a second focal plane depth.

[0008] The above-mentioned arrangement is used to form multi-focal plane imaging in a limited space. Since it is a head-mounted imaging structure, the space requirement is relatively high. Multiple reflectors are arranged to fold the light path to form a smaller volume. In addition, the mass of the reflectors is generally light to facilitate wearing, so that the entire head-mounted optical system is small in size and light in weight, bringing a good user experience to the viewer. In addition, the use of reflectors can also prevent dispersion, so that the color difference between the first focal plane and the second focal plane is smaller than that of the first light source and the second light source, and the picture quality is high.

[0009] Preferably, the splitting ratio of the first beam splitter is 1:1.

[0010] Through the above arrangement, the energy of the first light source and the second light source coupled into the optical system is basically consistent.

[0011] Preferably, the distance between the exit pupil center and the third reflector ranges from 50 mm to 60 mm.

[0012] Preferably, a local coordinate system is established with the exit pupil center as the origin as a reference, the extension direction of the optical axis of the exit pupil toward the third reflector is the Z axis, the direction perpendicular to the Z axis toward the upward direction is the Y axis, and the direction perpendicular to the ZOY plane toward the front is the X axis. The Z eccentricity range of the center of the first reflector is 53.5mm~62mm, the Y eccentricity range is 15mm-21mm, and the acute angle between the tangent plane at the origin of the first reflector and the YOZ plane is in the range of 12°-18°.

[0013] Preferably, a local coordinate system is established with the exit pupil center as the origin as a reference, the extension direction of the optical axis of the exit pupil toward the third reflector is the Z axis, the direction perpendicular to the Z axis toward the upward direction is the Y axis, and the direction perpendicular to the ZOY plane toward the front is the X axis. The Z eccentricity range of the center of the second reflector is 25mm~31mm, the Y eccentricity range is 16mm-22mm, and the acute angle between the tangent plane at the origin of the second reflector and the YOZ plane is in the range of 13°-19°.

[0014] Preferably, a local coordinate system is established with the exit pupil center as the origin as a reference, the direction of extension of the optical axis of the exit pupil toward the third reflector is the Z axis, the direction perpendicular to the Z axis toward the upward direction is the Y axis, and the direction perpendicular to the ZOY plane toward the front is the X axis. The Z eccentricity range of the third reflector center is 50mm~60mm, the Y eccentricity range is ±3mm, and the acute angle between the tangent plane at the origin of the third reflector and the YOZ plane is in the range of 14°-20°.

[0015] Preferably, the Z eccentricity range of the center of the first beam splitter is 34.5 mm to 42 mm, the Y eccentricity range is 25 mm to 31 mm, and the inclination angle range around the X axis is 8° to 16°.

[0016] Preferably, the distance between the first beam splitter and the first light source is in the range of 7mm-10mm, the distance between the first beam splitter and the second light source is in the range of 7mm-10mm, and the angles between the first light source and the second light source and the first beam splitter are both 45°.

[0017] Preferably, the focal length of the first reflector ranges from 18 mm to 22 mm.

[0018] Preferably, the focal length of the second reflector is in the range of 45 mm to 55 mm.

[0019] Preferably, the focal length of the third reflector ranges from 50 mm to 70 mm.

[0020] A head-mounted optical system is also provided, comprising a second beam splitter, wherein the second beam splitter replaces the third reflector in any of the above-mentioned head-mounted optical systems.

[0021] Through the above arrangement, light in the external environment can also enter the head-mounted optical system through the second beam splitter, thereby realizing the combination of virtual and real worlds. Further, the linkage between virtual and real worlds can be realized, the user experience can be improved, and other functions and designs can be developed on this basis, thereby increasing the development and design space.

[0022] Preferably, the reflectivity of the second beam splitter is greater than 50%.

[0023] The above arrangement reduces the light loss inside the optical system, thereby ensuring the brightness of the image formed by the light source in the viewer's eyes.

[0024] Compared with the prior art, the utility model is an optical system arranged in a head-mounted display device, so the size of the optical system is required to be high. By setting a plurality of reflectors to fold the optical path to form a smaller volume, the reflector is light in weight, which is also in line with the head-mounted use environment and is easy to wear. Furthermore, the reflector can effectively prevent dispersion and ensure that the color difference between the final image and the original image is shortened. In addition, two light sources are arranged in the optical system, and defocus stimulation can be achieved by adjustment, so that the depth of the two focal planes can be adjusted according to the situation of the viewer's eyes, and a more realistic three-dimensional display can be achieved. The optical system formed by the utility model can form a focal plane with a certain focal plane depth, that is, the formed image has a certain distance from the viewer's eyes, and the distance will not change because the human eye is close to or away from the exit pupil position, so as to prevent myopia caused by long-term viewing. In addition, the optical system can also allow light in the external environment to enter the optical system, so that the viewer can see the image corresponding to the light source while also seeing the external environment, thereby realizing the combination of virtual and reality. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this specification. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0026] Figure 1 Schematic diagram of the optical path structure of the head-mounted optical system in an embodiment of the utility model;

[0027] Figure 2 A schematic diagram of the optical path structure formed by the first focal plane in an embodiment of the utility model;

[0028] Figure 3 A schematic diagram of the optical path structure formed by the second focal plane in an embodiment of the utility model;

[0029] Figure 4 It is a structural schematic diagram of the external environment entering the head-mounted optical system for imaging in an embodiment of the utility model;

[0030] Figure 5 A schematic diagram of the eccentricity of each optical device of the optical system relative to the reference coordinates at the exit pupil in the embodiment of the utility model;

[0031] Figure 6 A schematic diagram of the optical path structure of a feasible implementation scheme in an embodiment of the utility model;

[0032] Figure 7 A schematic diagram of a sampling field MTF curve of a feasible implementation scheme in an embodiment of the utility model;

[0033] Figure 8 A schematic diagram of sampling field image points of a feasible implementation scheme in an embodiment of the utility model;

[0034] Fig. 9 A schematic diagram of a sampling field MTF curve of another feasible implementation scheme in an embodiment of the utility model;

[0035] Fig.10 A schematic diagram of sampling field image points of another feasible implementation scheme in an embodiment of the utility model;

[0036] Fig.11 A schematic diagram of the optical path structure of another feasible implementation scheme in the embodiment of the utility model;

[0037] Fig.12 A schematic diagram of a sampling field MTF curve corresponding to another feasible implementation scheme in an embodiment of the utility model;

[0038] Fig.13 The figure is a schematic diagram of sampling field image points corresponding to another feasible implementation scheme in the embodiment of the utility model.

[0039] Reference numerals:

[0040] 1. Exit pupil; 2. Third reflector; 3. Second reflector; 4. First reflector; 5. First beam splitter; 6. First light source; 7. Second light source; 8. First focal plane; 9. Second focal plane; 10. Second beam splitter 10. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0042] In the description of the embodiments of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the term "connected" should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection, or an integral connection can be a mechanical connection, or an electrical connection can be a direct connection, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0043] The terms "top", "bottom", "above", "lower", and "on" used throughout the description are relative to the relative positions of components of a device, such as the relative positions of the top and bottom substrates within a device. It is understood that devices are multifunctional regardless of their orientation in space.

[0044] To facilitate understanding of the embodiments of the present application, further explanation will be given below with reference to specific embodiments in conjunction with the accompanying drawings. The embodiments do not constitute a limitation on the embodiments of the present application.

[0045] This embodiment provides a head-mounted optical system, such as Figure 1-Figure 13 shown.

[0046] like Figure 1 As shown, the head-mounted optical system includes a light source component, a first beam splitter 5 and a reflection component.

[0047] The light source assembly includes a first light source 6 and a second light source 7, and the first light source 6 and the second light source 7 are used to provide light required by the head-mounted optical system.

[0048] The first beam splitter 5 is a plane beam splitter, including a first surface and a second surface, the first surface and the second surface are arranged opposite to each other, the first beam splitter 5 is arranged between the first light source 6 and the second light source 7, the first surface is opposite to the first light source 6, and the second surface is opposite to the second light source 7, so that the first surface receives light from the first light source 6, and the second surface receives light from the second light source 7.

[0049] The first beam splitter 5 can split the incident light into two optical paths emitted in different directions. Specifically, the first beam splitter 5 can allow a part of the light incident thereon to be transmitted to the outside of the first beam splitter 5 along the original propagation direction, and at the same time, can allow another part of the light incident thereon to be output from the incident surface in the form of reflection. The splitting ratio of the first beam splitter 5 determines the ratio of reflection and transmission of the light incident on the first beam splitter 5. Further, the splitting ratio of the plane beam splitter is 1:1, that is, of the light incident on the plane beam splitter, 50% of the light will be emitted in the form of transmission, and the remaining 50% of the light will be emitted in the form of reflection, so that the energy coupled into the optical system by the two light sources remains basically consistent.

[0050] That is, after the first light source 6 is incident on the first surface of the first beam splitter 5, a light path passing through the first beam splitter 5 in a transmission form and a light path passing through the first beam splitter 5 in a reflection form are formed. Similarly, after the second light source 7 is incident on the second surface of the first beam splitter 5, light paths output in a transmission form and a reflection form are formed.

[0051] In the head-mounted optical system formed in this embodiment, the optical path of the light emitted by the first light source 6 transmitted through the first beam splitter 5 is the first effective optical path, and the optical path of the light emitted by the second light source 7 reflected and emitted by the first beam splitter 5 is the second effective optical path. The light emitted by the first light source 6 as reflected and emitted by the first beam splitter 5 and the light emitted by the second light source 7 as transmitted light will be physically blocked by the external structure accommodating the head-mounted optical system, that is, the invalid optical path will not interfere with the formation and propagation of the effective optical path.

[0052] Furthermore, the distance range between the center of the first beam splitter 5 and the center of the first light source 6 is 7mm-10mm, and the acute angle between the first beam splitter 5 and the first light source 6 is 45°; similarly, the distance range between the center of the first beam splitter 5 and the center of the second light source 7 is 7mm-10mm, and the acute angle between the first beam splitter 5 and the second light source 7 is 45°.

[0053] The reflective assembly includes a first reflector 4, a second reflector 3 and a third reflector 2. Since the reflector has no dispersion compared to the lens, the final imaging is free of chromatic aberration, and multiple reflectors are used for reflection to fold the light path, thereby forming a more compact optical system structure. In order to improve the utilization rate of light energy, the first reflector 4, the second reflector 3 and the third reflector 2 are coated with a total reflection film. In an ideal case, all light reaching the surface of the reflective assembly can be reflected. In actual cases, the reflectivity is not less than 95%. The reflectors in the reflective assembly are all concave reflectors with positive optical power.

[0054] The first reflector 4 is arranged opposite to the first beam splitter 5. The light emitted by the first light source 6 passes through the first beam splitter 5 in a transmission manner and is incident on the first reflector 4. The light emitted by the second light source 7 is reflected on the first beam splitter 5 and is also incident on the first reflector 4. The focal length range of the first reflector 4 is 18 mm-22 mm.

[0055] The second reflector 3 is arranged opposite to the first reflector 4, so that the light reflected by the first reflector 4 is incident on the second reflector 3 and reflected again. The focal length range of the second reflector 3 is 45mm-55mm.

[0056] The third reflector 2 is arranged opposite to the second reflector 3. The light reflected by the second reflector 3 is incident on the third reflector 2 and reflected by the third reflector 2 toward the exit pupil 1. The focal length of the third reflector 2 is in the range of 50 mm to 70 mm. The distance between the center of the exit pupil 1 of the optical system and the third reflector 2 is in the range of 50 mm to 60 mm.

[0057] Based on the above optical system, such as Figure 2 As shown, the light emitted by the first light source 6 is incident on the first surface of the first beam splitter 5, passes through the first beam splitter 5 in the form of transmission and is incident on the first reflector 4, is reflected by the first reflector 4 and is incident on the second reflector 3, and is reflected again and is incident toward the third reflector 2, and finally the third reflector 2 emits the incident light toward the position of the exit pupil 1, forming a first focal plane with a first focal plane depth. Figure 3 As shown, the light emitted by the second light source 7 is incident on the second surface of the first beam splitter 5, and is reflected by the plane beam splitter to be incident on the reflective assembly, that is, it is reflected by the first reflector 4, the second reflector 3 and the third reflector 2 in sequence, and reaches the exit pupil 1 to form a second focal plane with a second focal plane depth.

[0058] Furthermore, the third reflector 2 can be replaced by the second beam splitter 10, or by a combination of a beam splitter film and a carrier plate. Figure 4As shown, the light from the external environment is allowed to enter the head-mounted optical system, so that the viewer can receive information about the external environment while viewing the first focal plane and the second focal plane, thereby realizing the combination of virtual and reality, and improving the fun of the combination of virtual and reality by setting the display content of the first light source 6 and the second light source 7. Furthermore, the reflectivity of the second beam splitter 10 or the beam splitter film is greater than 50%, so that the light loss inside the optical system is less, so as to ensure the brightness of the image formed by the light source in the viewer's eyes.

[0059] In the optical system formed by the above optical components, the diagonal field of view of the first focal plane and the second focal plane display light path is greater than 35°; the horizontal field of view should be greater than 29°. The diameter of the exit pupil 1 is greater than 10 mm. Figure 5 As shown, a local coordinate system is established with the center of the exit pupil 1 as the origin as a reference, the direction of the optical axis between the origin and the third reflector 2 is the Z axis direction, the direction perpendicular to the Z axis is the Y axis direction, and the direction perpendicular to the Y axis is the X axis direction. The Z eccentricity range of the center of the plane beam splitter is 34.5mm~42mm, the Y eccentricity range is 25mm-31mm, and the acute angle range between the plane beam splitter and the plane XOY is 8°-16°. The Z eccentricity range of the center of the first reflector 4 is 53.5mm~62mm, the Y eccentricity range is 15mm-21mm, and the acute angle range between the tangent plane at the origin of the first reflector 4 and the plane XOY is 12°-18°. The Z eccentricity range of the center of the second reflector 3 is 25mm~31mm, the Y eccentricity range is 16mm-22mm, and the acute angle range between the tangent plane at the origin of the second reflector 3 and the plane XOY is 13°-19°. The Z eccentricity range of the center of the third reflector 2 is 50mm-60mm, the Y eccentricity range is ±3mm, and the acute angle (Alpha angle) between the tangent plane at the origin of the third reflector 2 and the plane XOY ranges from 14° to 20°. The focal depth range of the head-mounted optical system is -10000mm to +1000mm.

[0060] In a feasible implementation of this embodiment, as Figure 6 Based on the optical parameters listed in Tables 1 to 3, the field of view of the head-mounted optical system is 35°, the diameter of the exit pupil 1 is 10 mm, the first focal plane depth and the second focal plane depth are both -5000 mm, and the focal length is 34.0 mm.

[0061] Table 1 Optical system parameters of the first focal plane display light path

[0062]

[0063] Among the above surfaces, the surface constituting the free-form surface satisfies the equation: c is the inverse of the radius of curvature, r is the radial distance of a point on the surface, k is the quadratic constant, C i are the coefficients of the higher-order terms.

[0064] Table 2 Free-form surface coefficients of the first focal plane display optical path

[0065]

[0066] Table 3 Optical system parameters of the second focal plane display light path

[0067]

[0068]

[0069] like Figure 7 As shown in the figure, the MTF of each sampling field is higher than 0.3 at 40lp / mm, indicating that the imaging quality of the system is excellent, where the horizontal axis represents the sampling frequency of the image space, the vertical axis represents the contrast, and F1~F9 are the sampling fields used to evaluate the display quality of the system. Figure 8 As shown, the size of the image point diagram of each sampling field of view is close to the diameter of the Airy disk, indicating that the imaging quality of the system is excellent, wherein the sampling field of view is marked on the left, the actual spot shape is in the middle, and the root mean square diameter of the spot of the corresponding field of view on the left is marked on the right.

[0070] In another feasible implementation of this embodiment, the optical path is roughly similar to the optical path of the previous feasible real-time method. Based on the optical parameters recorded in Tables 4 to 6, the field of view of the head-mounted optical system is 35°, the diameter of the exit pupil 1 is 10 mm, the first focal plane depth and the second focal plane depth are both -5000 mm; the focal length is 34.0 mm.

[0071] Table 4 Optical system parameters of the first focal plane display light path

[0072]

[0073]

[0074] Among the above surfaces, the surface constituting the free-form surface satisfies the equation: c is the inverse of the radius of curvature, r is the radial distance of a point on the surface, k is the quadratic constant, C i are the coefficients of the higher-order terms.

[0075] Table 2 Free-form surface coefficients of the first focal plane display optical path

[0076]

[0077]

[0078] Table 6 Optical system parameters of the second focal plane display light path

[0079]

[0080] like Fig. 9 As shown in the figure, the MTF of each sampling field is higher than 0.3 at 40lp / mm, indicating that the imaging quality of the system is excellent. Fig.10 As shown, the image point size of each sampling field of view is close to the diameter of the Airy disk, indicating that the imaging quality of the system is excellent.

[0081] In another feasible implementation of this embodiment, as Fig.11 Based on the optical parameters recorded in Tables 7 to 9, the field of view of the head-mounted optical system is 33°, the diameter of the exit pupil 1 is 10 mm, the first focal plane depth is -10000 mm, the second focal plane depth is +2000 mm, and the focal length is 33.8 mm.

[0082] Table 7 Optical system parameters of the first focal plane display light path

[0083]

[0084] Among the above surfaces, the surface constituting the free-form surface satisfies the equation: c is the inverse of the radius of curvature, r is the radial distance of a point on the surface, k is the quadratic constant, C i are the coefficients of the higher-order terms.

[0085] Table 8 The first focal plane shows the free surface coefficients of the optical path

[0086]

[0087]

[0088] Table 9 Second focal plane display optical path optical system parameters

[0089]

[0090]

[0091] like Fig.12 As shown in the figure, the MTF of each sampling field is higher than 0.3 at 40lp / mm, indicating that the imaging quality of the system is excellent. Fig.13 As shown, the image point size of each sampling field of view is close to the diameter of the Airy disk, indicating that the imaging quality of the system is excellent.

[0092] By setting up multiple reflectors as described above, long-distance imaging can be achieved in a limited space. In addition, the reflectors can effectively avoid dispersion, thereby ensuring the final chromatic aberration. The reflectors are light in weight, which can effectively improve the user experience for head-mounted near-eye optical systems. The two light sources set up at the same time can form images separately, and a more realistic three-dimensional display can be formed by arranging and setting the light source display images. At the same time, the focal plane depth of the image can be adjusted in a targeted manner so that the final image can form a defocus stimulus in the eye to inhibit the elongation of the eye axis.

[0093] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only the specific implementation method of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A head-mounted optical system, characterized in that: include: A light source assembly, comprising a first light source and a second light source; A first beam splitter is disposed between the first light source and the second light source, and two sides of the first beam splitter are disposed opposite to the first light source and the second light source respectively; A reflection assembly, comprising a first reflector, arranged opposite to the first beam splitter; a second reflector, arranged opposite to the first reflector; a third reflector, arranged opposite to the second reflector; The light emitted by the first light source is incident on the first reflector after being transmitted through the first beam splitter, and is reflected by the first reflector, the second reflector and the third reflector in sequence, and is emitted toward the exit pupil to form a first focal plane with a first focal plane depth; the light emitted by the second light source is incident on the first reflector after being reflected by the first beam splitter, and is reflected by the first reflector, the second reflector and the third reflector in sequence, and is emitted toward the exit pupil to form a second focal plane with a second focal plane depth.

2. The head-mounted optical system according to claim 1, characterized in that: The splitting ratio of the first beam splitter is 1:

1.

3. The head-mounted optical system according to claim 1, wherein: The distance between the exit pupil center and the third reflector is in the range of 50 mm to 60 mm.

4. The head-mounted optical system according to claim 1, wherein: A local coordinate system is established with the exit pupil center as the origin as a reference, the optical axis extension direction of the exit pupil toward the third reflector is the Z axis, the direction perpendicular to the Z axis toward the upward direction is the Y axis, and the direction perpendicular to the ZOY plane toward the front is the X axis. The Z eccentricity range of the first reflector center is 53.5mm~62mm, the Y eccentricity range is 15mm-21mm, and the acute angle between the tangent plane at the origin of the first reflector and the YOZ plane is in the range of 12°-18°.

5. The head-mounted optical system according to claim 1, wherein: A local coordinate system is established with the exit pupil center as the origin as a reference, the extension direction of the optical axis of the exit pupil toward the third reflector is the Z axis, the direction perpendicular to the Z axis toward the upward direction is the Y axis, and the direction perpendicular to the ZOY plane toward the front is the X axis. The Z eccentricity range of the second reflector center is 25mm~31mm, the Y eccentricity range is 16mm-22mm, and the acute angle between the tangent plane at the origin of the second reflector and the YOZ plane is in the range of 13°-19°.

6. The head-mounted optical system according to claim 5, characterized in that: A local coordinate system is established with the exit pupil center as the origin as a reference, the extension direction of the optical axis of the exit pupil toward the third reflector is the Z axis, the direction perpendicular to the Z axis toward the upward direction is the Y axis, and the direction perpendicular to the ZOY plane toward the front is the X axis. The Z eccentricity range of the third reflector center is 50mm~60mm, the Y eccentricity range is ±3mm, and the acute angle between the tangent plane at the origin of the third reflector and the YOZ plane is in the range of 14°-20°.

7. The head-mounted optical system according to claim 6, wherein: The center of the first beam splitter has a Z eccentricity range of 34.5 mm to 42 mm, a Y eccentricity range of 25 mm to 31 mm, and a tilt angle range around the X axis of 8° to 16°.

8. The head-mounted optical system according to claim 1, wherein: The distance between the first beam splitter and the first light source is in the range of 7mm-10mm, the distance between the first beam splitter and the second light source is in the range of 7mm-10mm, and the angles between the first light source and the second light source and the first beam splitter are both 45°.

9. The head-mounted optical system according to claim 4, wherein: The focal length of the first reflector ranges from 18 mm to 22 mm.

10. The head-mounted optical system according to claim 5, characterized in that: The focal length of the second reflector is in the range of 45 mm to 55 mm.

11. The head-mounted optical system according to claim 6, wherein: The focal length of the third reflector ranges from 50 mm to 70 mm.

12. A head-mounted optical system, characterized in that: It comprises a second beam splitter, which replaces the third reflector in any one of the head-mounted optical systems of claims 1-11.

13. The head-mounted optical system according to claim 12, wherein: The reflectivity of the second beam splitter is greater than 50%.

Images