AR light machine with backlight side surface

Abstract

The utility model provides a side face backlight AR light machine, and relates to the technical field of augmented reality, the side face backlight AR light machine comprises an illumination module, a light splitting element, a lens group, a display screen and a front group lens, illumination light emitted by the illumination module emits first light through the light splitting element, and the first light is emitted to the lens group and the display screen to form emergent light; the emergent light is reflected by the display screen and then is emitted through the lens group, the light splitting element and the front group of lenses. The lighting system and the imaging system share one set of lens group, so that the size and the weight of an optical machine are effectively reduced, the optical path is optimized, and the definition and the brightness of an image are ensured. The integrated design not only simplifies the structure of the optical machine and reduces the production cost, but also provides more comfortable and portable use experience for final users. Therefore, the application scene of the utility model provides a new optical system solution for the wearable AR equipment, and aims to meet the requirements of modern consumers for the characteristics of high performance, high integration and portability so as to improve the user experience.

Description

Technical Field

[0001] The present application relates to the field of augmented reality technology, and in particular to an AR optical machine with side backlight. Background Art

[0002] The optical system in the field of augmented reality (AR) relies on optical components such as lens groups, reflectors and light sources to capture, process and project images. In the projection scheme of optical projectors (optical machines), light is generally provided by illumination light sources, so a built-in illumination system is required; the illumination system includes the light source itself and a lens group composed of multiple lenses, which guides and adjusts the light to achieve the desired imaging effect.

[0003] However, there are some problems with this type of design requirement. The integration of additional lens groups and lighting systems will significantly increase the size of the optical machine and increase the weight of the entire system, which in turn increases the complexity of design and manufacturing, affecting the portability and user experience of the product. Utility Model Content

[0004] The purpose of the embodiments of the present application is to provide an AR optical machine with a side backlight, which can reduce the volume and weight of the optical machine without sacrificing optical performance.

[0005] According to one aspect of an embodiment of the present application, a side-backlit AR optical machine is provided, comprising a lighting module, a spectroscopic element, a lens group, a display screen and a front lens group, wherein the lighting light emitted by the lighting module emits a first light ray through the spectroscopic element, the first light ray is emitted to the lens group and the display screen to form an emergent light ray, the emergent light ray is reflected by the display screen and then emitted through the lens group, the spectroscopic element and the front lens group.

[0006] Optionally, the front group of lenses, the beam splitter element, the lens group, and the display screen are arranged in sequence along a first direction, and the lighting module is arranged on one side of the beam splitter element along a second direction; the second direction is perpendicular to the first direction.

[0007] Optionally, the lighting module, the beam splitter element, the lens group, and the display screen are arranged in sequence along a first direction, and the front lens group is arranged on one side of the beam splitter element along a second direction; the second direction is perpendicular to the first direction.

[0008] Optionally, a light absorbing element is further included, for absorbing a second light emitted by the illumination light through the light splitting element.

[0009] Optionally, the beam splitter element is a polarization beam splitter, the first light forms a first polarized light, the second light forms a second polarized light, and the outgoing light forms a third polarized light.

[0010] Optionally, the lighting module includes multiple light sources with different wavelengths, and a turning element is arranged between the lighting module and the spectroscopic element. The turning element has different turning angles for the illumination lights of different wavelengths so as to direct the illumination lights of different wavelengths to be emitted in parallel to the spectroscopic element.

[0011] Optionally, the lighting module includes a light source and a converging lens, wherein the converging lens includes at least a convex lens and / or a metasurface lens;

[0012] And / or, further comprising an optical fiber, wherein a curved lens is disposed at a light output end of the optical fiber;

[0013] And / or, it also includes a light homogenizing element, and the light homogenizing element is used to evenly irradiate the illumination light toward the light splitting element.

[0014] Optionally, the light homogenizing element includes a fly-eye lens, and the fly-eye lens includes a plurality of micro lenses.

[0015] Optionally, the light homogenizing element is an optical waveguide, and an entrance pupil grating and an exit pupil grating are arranged on the optical waveguide. The entrance pupil grating is used to couple the illumination light into the optical waveguide for total reflection propagation, and the illumination light is coupled out by the exit pupil grating after multiple total reflections in the optical waveguide.

[0016] Optionally, the light homogenizing element is a light rod, which is also provided with an inclined surface inclined to the incident surface and a curved surface connected to the exit surface. After the illumination light is incident from the incident surface, it is reflected once by the inclined surface and twice by the curved surface, and then emitted from the exit surface to the spectroscopic element.

[0017] In the side-backlit AR optical machine provided in the embodiment of the present application, the illumination light emitted by the illumination module is divided into a first light and a second light by a spectroscopic element, the second light is absorbed, and the first light is emitted to the lens group and the display screen to form an outgoing light, which is then reflected and emitted through the lens group, the spectroscopic element and the front lens group. The illumination system and the imaging system of the present application share a set of lens groups, which effectively reduces the size and weight of the optical machine, while optimizing the optical path and ensuring the clarity and brightness of the image. This integrated design not only simplifies the structure of the optical machine and reduces production costs, but also provides a more comfortable and portable use experience for end users. Therefore, the application scenario of the present application provides a new optical system solution for wearable AR devices, which aims to meet the requirements of modern consumers for high performance, high integration and lightweight characteristics to enhance user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 This is one of the schematic diagrams of the AR optical machine structure with side backlight provided in this embodiment;

[0020] Figure 2 This is the second schematic diagram of the AR optical machine structure with side backlight provided in this embodiment;

[0021] Figure 3 This is the third schematic diagram of the AR optical machine structure with side backlight provided in this embodiment;

[0022] Figure 4 This is the fourth schematic diagram of the AR optical machine structure with side backlight provided in this embodiment;

[0023] Figure 5 This is the fifth schematic diagram of the AR optical machine structure with side backlight provided in this embodiment;

[0024] Figure 6 Schematic diagram of the compound eye lens structure of the side-backlit AR optical machine provided in this embodiment;

[0025] Figure 7 This is the sixth schematic diagram of the AR optical machine structure with side backlight provided in this embodiment;

[0026] Figure 8 This is the seventh schematic diagram of the AR optical machine structure with side backlight provided in this embodiment;

[0027] Fig. 9 This is the eighth schematic diagram of the AR optical machine structure with side backlight provided in this embodiment;

[0028] Fig.10 is a cross-sectional view of the AR optical cable with side backlight provided in this embodiment;

[0029] Fig.11 This is a diagram of the curved lens of the side-backlit AR optical machine provided in this embodiment.

[0030] Icons: 10-illumination module; 10a-light source; 11-spectrometer; 12-lens group; 13-display screen; 14-front lens group; 15-light absorbing element; 16-convex lens; 17-turning element; 18-compound eye lens; 19-metasurface lens; 20-optical waveguide; 20a-entrance pupil grating; 20b-exit pupil grating; 21-light rod; 21a-inclined surface; 21b-curved surface; 22-optical fiber; 22a-curved lens; F1-first direction; F2-second direction. DETAILED DESCRIPTION

[0031] The technical solutions 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.

[0032] In the description of this application, it should be noted that the terms "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0033] It should also be noted that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0034] With the development of technology and the increasing requirements of users for portability and experience, traditional optical machine design has been unable to meet market demand. Therefore, finding a design solution that can reduce the size and weight of the optical machine without sacrificing optical performance has become an important research direction in the AR field.

[0035] Therefore, please refer to Figure 1 , Figure 2 The embodiment of the present application provides an AR optical machine with a side backlight, including: an illumination module 10, a spectroscopic element 11, a lens group 12, a display screen 13 and a front lens group 14. The illumination light emitted by the illumination module 10 is divided into a first light and a second light by the spectroscopic element 11, the second light is absorbed, and the first light is emitted to the lens group 12 and the display screen 13 to form an outgoing light. The outgoing light is reflected and emitted through the lens group 12, the spectroscopic element 11 and the front lens group 14.

[0036] The lighting module 10 includes a light source 10a therein. The light source 10a may be a monochromatic light source or a multicolor light source of RGB three primary colors. The light source 10a is commonly an LED light source or an LD light source.

[0037] The spectroscopic element 11 has two main functions in the present application. One is to direct the illumination light emitted by the illumination module 10 to the display screen 13; the other is to direct the outgoing light with image information on the display screen 13 after illumination to the front lens group 14, thereby completing the optical machine imaging light emitting process.

[0038] Due to the structural design of the present application, the above two processes have different requirements for the spectroscopic element 11. One process utilizes the light reflected by the spectroscopic element 11, and the other process utilizes the light transmitted by the spectroscopic element 11; therefore, the spectroscopic element 11 must have both reflection and transmission modes.

[0039] To meet the above requirements, the beam splitter 11 may include a half-reflective half-mirror, a polarization beam splitter, etc. If the display screen 13 is an LCOS (liquid crystal on silicon) screen, then the beam splitter 11 is usually a polarization beam splitter. The LCOS screen can rotate the polarization direction of the incident light by nearly 90°, for example, S-polarized light is incident and P-polarized light is emitted, so the polarization beam splitter is a common combination of LCOS.

[0040] The lens group 12 includes a plurality of different lenses, and the optical parameters will not change after being set in the early stage. It cooperates with the display screen 13 to output the outgoing light with image information to the outside world. The parameters of some optical elements in the aforementioned lighting module 10 are set according to the lens group 12 and cooperate with it.

[0041] The display screen 13 is any display screen 13 that cannot emit light by itself and needs a backlight source, such as LCOS, DLP, etc.

[0042] The front lens group 14 is used to enable the display screen 13 to output the outgoing light with image information to the outside, thereby realizing imaging light.

[0043] It can be seen that the lighting module 10, the spectroscopic element 11, the lens group 12 to the display screen 13 can be used as a lighting system to provide lighting for the display screen 13; the lens group 12, the spectroscopic element 11, and the front lens group 14 are used as an imaging system for imaging; the lighting system and the imaging system share a lens group 12, which can reduce the size and weight of the AR optical machine.

[0044] In the prior art, since some projection solutions (such as LCOS, DLP, etc.) rely on the illumination light source to provide light, a built-in illumination light path system is required. This illumination light path system includes not only the light source itself, but also a lens group composed of multiple lenses. This means that in the prior art, this type of optical machine is equipped with at least two sets of lens groups, one for projection imaging and the other for illumination.

[0045] The present application is different from the above-mentioned prior art in that the projection system and the illumination system share a set of lens groups 12, maximizing the use of the lens groups 12, thereby reducing the volume and weight of the optical machine.

[0046] In the side-backlit AR optical machine provided in the embodiment of the present application, the illumination light emitted by the illumination module 10 is divided into a first light and a second light by the spectroscopic element 11, the second light is absorbed, and the first light is emitted to the lens group 12 and the display screen 13 to form an outgoing light, which is then reflected and emitted through the lens group 12, the spectroscopic element 11 and the front lens group 14. The illumination system and the imaging system of the present application share a set of lens groups 12, which effectively reduces the size and weight of the optical machine, while optimizing the optical path and ensuring the clarity and brightness of the image. This integrated design not only simplifies the structure of the optical machine and reduces production costs, but also provides a more comfortable and portable use experience for end users. Therefore, the application scenario of the present application provides a new optical system solution for wearable AR devices, which aims to meet the requirements of modern consumers for high performance, high integration and lightweight characteristics to enhance user experience.

[0047] In one embodiment of the present application, Figure 1 As shown, the front lens group 14, the beam splitter element 11, the lens group 12, and the display screen 13 are arranged in sequence along the first direction F1, and the lighting module 10 is arranged on one side of the beam splitter element 11 along the second direction F2; the second direction F2 is perpendicular to the first direction F1.

[0048] In this embodiment, the lens group 12 is located on the reflection side of the spectroscopic element 11. The first light is reflected toward the lens group 12 and the display screen 13 to form an outgoing light. The outgoing light is then reflected back and emitted through the lens group 12, the spectroscopic element 11 and the front lens group 14.

[0049] After the second light is transmitted through the light splitting element 11, it is absorbed on the transmission side of the light splitting element 11. For example, Figure 3 As shown, along the second direction F2 , a light absorbing element 15 is further disposed on the side of the light splitting element 11 away from the lighting module 10 for absorbing the second light. In other words, the light absorbing element 15 is located on the transmission side of the light splitting element 11 .

[0050] When the illumination light emitted by the illumination module 10 reaches the light splitting element 11, it is split into a first light and a second light by the light splitting element 11. Only the first light will be directed to the display screen 13, and the second light will be lost. If the light absorbing element 15 is not provided, the second light will generate heat inside the optical machine, causing the optical machine to heat up, which may affect the performance of some components inside the optical machine, and may also form stray light, reducing the imaging quality and contrast. Therefore, a light absorbing element 15 is provided on the subsequent optical path of the second light to absorb the second light, so as to improve the above structural design.

[0051] The light absorbing element 15 may be some thin films, such as graphene materials. When the light absorbing element 15 is made of light absorbing materials, it may be disposed on the optical machine housing.

[0052] In another embodiment, Figure 2 As shown, the lighting module 10 and the projection module are located in the same direction, and the display screen 13 receives the light directly transmitted by the illumination light after passing through the beam splitter 11. The lighting module 10, the beam splitter 11, the lens group 12, and the display screen 13 are sequentially arranged along the first direction F1, and the front lens group 14 is arranged on one side of the beam splitter 11 along the second direction F2; the second direction F2 is perpendicular to the first direction F1.

[0053] At this time, the lens group 12 is located on the transmission side of the spectrometer 11. The first light is transmitted to the lens group 12 and the display screen 13 to form an outgoing light. The outgoing light is reflected by the lens group 12 and the spectrometer 11 and then emitted to the front lens group 14.

[0054] In this embodiment, a light absorbing element 15 may be disposed on the reflective side of the light splitting element 11 to absorb the second light.

[0055] The only difference between this embodiment and the previous embodiment is that the light received / emitted by the display screen 13 is transmitted light or reflected light, and there is no essential difference, which will not be described here.

[0056] As mentioned above, the spectroscopic element 11 is an optical element with semi-reflective and semi-transmissive or polarized spectroscopic function, which can ensure that the display screen 13 receives the illumination light from the illumination module 10 and transmit the outgoing light emitted by the display screen 13 to form an optical image.

[0057] Taking the example that the light splitting element 11 reflects the first light toward the lens group 12 and the display screen 13 , when the display screen 13 is an LCOS display screen, the light splitting element 11 is a polarization beam splitter PBS; the lighting module 10 includes an LED lamp or an LD lamp.

[0058] Reflection and transmission occur on the surface of PBS, the first light forms the first polarized light, the second light forms the second polarized light, and the outgoing light forms the third polarized light.

[0059] Among them, the reflected light is the first polarized light, and the transmitted light is the second polarized light, and the polarization directions of the two are perpendicular. The second polarized light continues to propagate along the original optical path and is lost. The first polarized light passes through the lens group 12 and enters the LCOS display screen. The LCOS display screen rotates its polarization state by 90° and reflects it to form a third polarized light. The polarization state of the third polarized light is the same as that of the second polarized light, and the third polarized light already carries the image information to be displayed. Since the third polarized light has the same polarization state as the second polarized light, the third polarized light directly transmits the PBS and then exits from the front lens group 14 to display the image.

[0060] The lighting module 10 may include a single light source or multiple light sources 10a with different wavelengths. A turning element 17 is provided between the lighting module 10 and the spectroscopic element 11. The turning element 17 has different turning angles for lighting lights of different wavelengths so as to direct the lighting lights of different wavelengths to be emitted in parallel to the spectroscopic element 11.

[0061] For example Figure 4 As shown, the lighting module 10 includes a plurality of LED lights of three colors, RGB, and a converging lens, such as a convex lens 16, is arranged on the optical path of the lighting light. There is also a turning element 17 behind the optical path of the convex lens 16. Because the lighting lights of the three colors are not parallel after passing through the convex lens 16, the lighting lights of the three colors cannot be combined to form uniform white light. Therefore, the turning element 17 is arranged. The turning angles of the turning element 17 for lights of different wavelengths (colors) are different. After the angle setting of the turning element 17, the lighting lights of the three colors can finally be emitted in parallel.

[0062] In addition, the lighting module 10 includes a light source 10 a and a converging lens, which includes at least a convex lens 16 and / or a metasurface lens 19 .

[0063] And / or, the lighting module 10 further includes an optical fiber 22 , and a curved lens 22 a is disposed at the light-emitting end of the optical fiber 22 .

[0064] And / or, the lighting module 10 further includes a light homogenizing element, and the light homogenizing element is used to evenly irradiate the lighting light toward the light splitting element 11 .

[0065] like Figure 5 As shown, the convex lens 16 is arranged on the surface of the LED lamp, and its function is to converge the light beam, thereby reducing the divergence of the light beam; the convex lens 16 convexes toward the light splitting element 11; it can also be other lenses, spherical or aspherical, to achieve the function of converging light.

[0066] The metasurface lens 19 has a similar function to an ordinary lens and can also shrink divergent light, but the metasurface lens 19 is smaller and thinner.

[0067] In the example of the present application, a convex lens 16 and a metasurface lens 19 are sequentially arranged on the light-emitting side of the light source 10a, and a light-homogenizing element is also arranged on the light-emitting side of the metasurface lens 19. In one implementation, the light-homogenizing element is a fly-eye lens 18, and its enlarged side view is as follows: Figure 6 As shown, there are many micro lenses on the surface of the compound eye lens 18, which can homogenize the incident light. Homogenization refers to the uniform distribution of light intensity in each angle range, which is the premise for the optical machine to output high-quality images. The specific homogenization principle belongs to the common technology in this field and will not be repeated in this embodiment.

[0068] On the light output path of the lighting module 10, a converging lens is provided to adjust the divergence angle of the light beam, such as a common lens or a metasurface lens 19; a uniform light element is also provided to make the light field uniform, such as a light rod 21, a compound eye lens 18, an optical waveguide 20, etc. The specific parameters of the above optical devices are set according to the lens group 12.

[0069] In yet another implementation, referring to Figure 7 The light homogenizing element is an optical waveguide 20, on which an entrance pupil grating 20a and an exit pupil grating 20b are arranged. The entrance pupil grating 20a is used to couple the illumination light into the optical waveguide 20 for total reflection propagation, and the illumination light is coupled out by the exit pupil grating 20b after multiple total reflections in the optical waveguide 20.

[0070] The light homogenizing element uses an optical waveguide 20 to replace the fly-eye lens 18. The advantage of the light homogenizing of the optical waveguide 20 is that the optical waveguide 20 is thinner and smaller than the fly-eye lens 18. The optical waveguide 20 is mainly provided with an entrance pupil grating 20a and an exit pupil grating 20b. The former is used to couple the light emitted by the light source 10a into the optical waveguide 20 for total reflection propagation. After multiple total reflections, the light field distribution can become uniform, and then it is coupled out of the optical waveguide 20 through the exit pupil grating 20b. The existence of the exit pupil grating 20b can also expand the pupil.

[0071] A convex lens 16 may also be provided between the light source 10a and the entrance pupil grating 20a. The convex lens 16 shrinks the illumination light, which is beneficial for all the emitted illumination light to be coupled into the optical waveguide 20 through the entrance pupil grating 20a. Because the area of ​​the entrance pupil grating 20a is usually small, if the spot area is too large, some edge illumination light will be lost.

[0072] In another implementation, Figure 8 As shown, the light homogenizing element is a light rod 21, which is also provided with an inclined surface 21a inclined to the incident surface and a curved surface 21b connected to the exit surface. After the illumination light is incident from the incident surface, it is reflected once by the inclined surface 21a and twice by the curved surface 21b, and then emitted from the exit surface to the spectroscopic element 11.

[0073] The light rod 21 is provided with an inclined surface 21a and a curved surface 21b, wherein the inclined surface 21a is close to the incident surface, and the curved surface 21b is close to the exit surface. The optical parameters such as the curvature of the curved surface 21b are set according to the optical design of the projection system. For example, the inclined surface 21a and the curved surface 21b are arranged opposite to each other, and respectively reflect the incident illumination light once and twice. The illumination light enters the light rod 21 from the incident surface, and is emitted from the exit surface after being reflected by the inclined surface 21a for the first time and the curved surface 21b for the second time.

[0074] The light uniformity principle of the light rod 21 is based on reflection and scattering. The uneven light is evenly mixed after multiple reflections and scattering and then emitted. Figure 8 It can be clearly seen that the multiple light sources 10a of this embodiment are arranged inward along the paper surface. The reason for this arrangement is that when the light emitted by the subsequent light sources 10a hits the inclined surface 21a of the light rod 21, the emitted light of the multiple light sources 10a begins to reflect at the same height inside the light rod 21, so as to avoid excessive directional differences in the propagation of light emitted by different light sources 10a.

[0075] In another implementation, the light homogenizing element is Fig. 9 The optical fiber 22 shown has a curved lens 22a disposed at the light output end of the optical fiber 22 .

[0076] The lighting system is implemented in the form of optical fiber 22 + light source 10a. For example, each light source 10a in the RGB three-color light source is connected to at least one optical fiber 22, and multiple optical fibers 22 are gathered to form an optical cable, such as Fig.10 The cross-sectional view of the optical cable is shown in FIG. 2 , and the end of the optical cable is a curved lens 22a. The partial enlarged view is shown in FIG. Fig.11 As shown, the curved lens 22a is used to shrink the illumination light passing through the optical fiber 22, and the parameters of the curved lens 22a are related to the optical design of the projection light path.

[0077] The lighting system uses a multi-channel optical fiber 22 to integrate an optical cable and is combined with multiple light sources 10a. The lighting system can be placed in other areas outside the optical machine, and only the projection system is placed inside the optical machine. For example, in AR glasses, the optical machine is at the front end of the head close to the glasses, and the above-mentioned lighting system can be pulled to the back end of the head. In this way, the size and weight of the optical machine will be smaller, and the lighting system is placed at the back end, the overall weight distribution is more even, and the user is more comfortable to wear.

[0078] In summary, in the side-backlit AR optical machine provided in the embodiment of the present application, the lighting system and the imaging system share a set of lens groups 12 of the imaging system, and some optical parameters of the lighting system are set according to the lens group 12; compared with the multiple lens groups 12 in the prior art, the present application reduces the use of at least one lens group 12, and provides a variety of lighting schemes, which is conducive to reducing the size and weight of the optical machine, thereby facilitating the subsequent assembly of the whole machine, reducing the weight of the equipment, and improving the user experience.

[0079] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A side-backlit AR optical machine, characterized in that: include: An illumination module, a beam splitter, a lens group, a display screen and a front lens group, wherein the illumination light emitted by the illumination module emits a first light beam through the beam splitter, the first light beam is emitted to the lens group and the display screen to form an outgoing light beam, and the outgoing light beam is reflected by the display screen and then emitted through the lens group, the beam splitter and the front lens group.

2. The side-backlit AR optical machine according to claim 1, characterized in that: The front lens group, the beam splitter element, the lens group, and the display screen are arranged in sequence along a first direction, and the lighting module is arranged on one side of the beam splitter element along a second direction; the second direction is perpendicular to the first direction.

3. The side-backlit AR optical machine according to claim 1, characterized in that: The lighting module, the beam splitter, the lens group, and the display screen are arranged in sequence along a first direction, and the front lens group is arranged on one side of the beam splitter along a second direction; the second direction is perpendicular to the first direction.

4. The side-backlit AR optical machine according to claim 1, characterized in that: It also includes a light absorbing element for absorbing the second light emitted by the illumination light through the light splitting element.

5. The side-backlit AR optical machine according to claim 4, characterized in that: The beam splitter is a polarization beam splitter, the first light forms a first polarized light, the second light forms a second polarized light, and the outgoing light forms a third polarized light.

6. The side-backlit AR optical machine according to claim 1, characterized in that: The lighting module includes multiple light sources with different wavelengths. A turning element is arranged between the lighting module and the spectroscopic element. The turning element has different turning angles for the lighting lights of different wavelengths so as to emit the lighting lights of different wavelengths in parallel to the spectroscopic element.

7. The side-backlit AR optical machine according to any one of claims 1 to 6, characterized in that: The lighting module includes a light source and a converging lens, wherein the converging lens includes at least a convex lens and / or a metasurface lens; And / or, further comprising an optical fiber, wherein a curved lens is disposed at a light output end of the optical fiber; And / or, it also includes a light homogenizing element, and the light homogenizing element is used to evenly irradiate the illumination light toward the light splitting element.

8. The side-backlit AR optical machine according to claim 7, characterized in that: The light homogenizing element includes a fly-eye lens, and the fly-eye lens includes a plurality of micro lenses.

9. The side-backlit AR optical machine according to claim 7, characterized in that: The light homogenizing element is an optical waveguide, on which an entrance pupil grating and an exit pupil grating are arranged. The entrance pupil grating is used to couple the illumination light into the optical waveguide for total reflection propagation, and the illumination light is coupled out by the exit pupil grating after multiple total reflections in the optical waveguide.

10. The side-backlit AR optical machine according to claim 7, characterized in that: The light homogenizing element is a light rod, which is also provided with an inclined surface inclined with respect to the incident surface and a curved surface connected with the exit surface. After the illumination light is incident from the incident surface, it is reflected once by the inclined surface and twice by the curved surface, and then emitted from the exit surface to the light splitting element.

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