Prism turn-back type near-to-eye display system and wearable device

Abstract

The invention provides a prism turn-back type near-to-eye display system and wearable equipment, and the system comprises an image source which is used for emitting display light; the prism optical assembly forms a turn-back type display light path; the prism optical assembly comprises at least one prism, a first wave plate, a polarization beam splitting surface and a semi-transparent and semi-reflective beam splitting surface; the dimming assembly is arranged on the transmission side of the semi-transmitting and semi-reflecting light splitting surface; the first wave plate is arranged on the reflection side of the polarization beam splitting surface, and the semi-transparent and semi-reflective beam splitting surface is arranged at the downstream of the first wave plate; the dimming assembly comprises a second wave plate, a first polarization layer, a liquid crystal layer and a second polarization layer which are sequentially arranged along the transmission light path, and the first wave plate, the second wave plate, the polarization light splitting surface and the first polarization layer are arranged in a matched mode, so that display light can be prevented from leaking through the dimming assembly by means of the characteristics of the prism, liquid crystal and polarized light, and the display quality is improved. The privacy of a user is protected, the influence on other people is avoided, the field angle is greatly improved, and the total thickness of the system is reduced.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to optical technology, wearable devices, and in particular to a prism fold return near-eye display system and a wearable device. BACKGROUND

[0002] AR (Augmented Reality) glasses can project virtual images into the human eye at the same time as real-world images, so that the user can see virtual images superimposed on real scenes. AR glasses can bring great convenience to people's learning, work, life, entertainment and other aspects. When users obtain visual text, images and video information, they can not only move freely, but also free their hands, greatly facilitating people's daily life. AR glasses technology has developed rapidly in recent years and has been successfully applied to many fields such as military equipment, industrial production, medical diagnosis, and daily life and entertainment.

[0003] Currently available AR glasses generally include AR glasses based on different optical principles such as planar semi-transparent semi-reflective, free-form surface semi-transparent semi-reflective, geometric light waveguide, catadioptric structure, and diffractive light waveguide. In related technologies, AR glasses have the problems of small field of view angle and large thickness. SUMMARY

[0004] To solve the above technical problems, the present disclosure is proposed. Embodiments of the present disclosure provide a prism fold return near-eye display system and a wearable device.

[0005] Embodiments of the present disclosure provide a prism fold return near-eye display system, which includes: an image source configured to emit display light; a prism optical assembly configured to form a fold return display light path; the prism optical assembly includes at least one prism, a first wave plate, a polarization beam splitting surface, and a semi-transparent semi-reflective beam splitting surface; the prism has an incident surface configured to receive the display light, and a total reflection surface arranged inside the prism, the total reflection surface is configured to change a propagation direction of the display light after at least one total reflection in the prism; the polarization beam splitting surface includes a reflection side and a transmission side, and is configured to transmit light having a first polarization state in incident light and reflect light having a second polarization state different from the first polarization state; the first wave plate is arranged on the reflection side of the polarization beam splitting surface, and the semi-transparent semi-reflective beam splitting surface is arranged downstream of the first wave plate and is configured to partially reflect and partially transmit incident light; a light modulation assembly is arranged on the transmission side of the semi-transparent semi-reflective beam splitting surface; the light modulation assembly includes a second wave plate, a first polarization layer, a liquid crystal layer, and a second polarization layer arranged in sequence along a transmission light path, wherein the first wave plate, the second wave plate, the polarization beam splitting surface, and the first polarization layer are arranged in cooperation with each other.

[0006] In some embodiments, the at least one prism comprises: a first prism, a second prism and a third prism, the first prism has a second surface that totally reflects the display light, a third surface of the first prism and a sixth surface of the third prism are mutually attached, and the polarization splitting surface is located between the attached surfaces; and the second prism is located on a side of the first prism close to the second surface.

[0007] In some embodiments, a partial reflection film is arranged on a side of the second prism away from the first prism, forming a semi-transmissive and semi-reflective splitting surface.

[0008] In some embodiments, the at least one prism further comprises: a fourth prism arranged between the second prism and the light adjusting assembly, and the fourth prism has a refractive power that cancels out the refractive power of the prism group composed of the first prism, the second prism and the third prism.

[0009] In some embodiments, the fourth prism is glued to a fifth surface of the second prism, or there is an air gap with a first preset width between the fourth prism and the fifth surface.

[0010] In some embodiments, the system further comprises: a first polarizer arranged on the light exit side of the image source.

[0011] In some embodiments, the first polarizer is a linear polarizer.

[0012] In some embodiments, the first wave plate is arranged between the reflection side of the polarization splitting surface and the semi-transmissive and semi-reflective splitting surface.

[0013] In some embodiments, along the direction of the display light, the fast axis of the first wave plate is deflected by a preset angle relative to the pass axis of the polarization splitting surface in a clockwise direction; along the direction of the display light, the fast axis of the second wave plate is deflected by a preset angle relative to the extinction axis of the first polarizer in a clockwise direction; the preset angle is in the interval of 40° to 50°; or along the direction of the display light, the fast axis of the first wave plate is deflected by a preset angle relative to the pass axis of the polarization splitting surface in a counterclockwise direction; along the direction of the display light, the fast axis of the second wave plate is deflected by a preset angle relative to the extinction axis of the first polarizer in a counterclockwise direction; the preset angle is in the interval of 40° to 50°.

[0014] In some embodiments, the first wave plate is a quarter wave plate; and the second wave plate is a quarter wave plate.

[0015] In some embodiments, the first wave plate is attached to the optical surface of the second prism close to the first prism.

[0016] In some embodiments, the first wave plate and the second surface of the first prism have an air gap with a second preset width.

[0017] In some embodiments, the second preset width is greater than or equal to 0.01 mm.

[0018] In some embodiments, the first waveplate is attached to the side of the polarization beam splitter near the reflection side, and the system further includes a third waveplate disposed between the first polarizer and the prism optical assembly.

[0019] In some embodiments, along the direction of the displayed light, the fast axis of the first waveplate is deflected counterclockwise by a predetermined angle relative to the optical axis of the polarizing beam splitter; along the direction of the displayed light, the fast axis of the third waveplate is deflected counterclockwise by a predetermined angle relative to the optical axis of the first polarizer; the predetermined angle is in the range of 40° to 50°; or along the direction of the displayed light, the fast axis of the first waveplate is deflected clockwise by a predetermined angle relative to the optical axis of the polarizing beam splitter; along the direction of the displayed light, the fast axis of the third waveplate is deflected clockwise by a predetermined angle relative to the optical axis of the first polarizer; the predetermined angle is in the range of 40° to 50°.

[0020] In some embodiments, the first waveplate is a quarter-wave plate and the third waveplate is a quarter-wave plate.

[0021] In some embodiments, the system further includes a second polarizer disposed on the transmission side of the polarization beam splitter, wherein the polarization direction of the second polarizer is set to be consistent with the transmission polarization direction of the polarization beam splitter.

[0022] In some embodiments, the polarization direction of the first polarization layer is perpendicular to the polarization direction of the second polarization layer.

[0023] In some embodiments, the type of liquid crystal layer includes any of the following: twisted nematic liquid crystal, liquid crystal with guest-host effect characteristics, liquid crystal with electrically controlled birefringence characteristics, and Pi-cells liquid crystal.

[0024] In some embodiments, an antireflective film is provided on the inner and / or outer surfaces of the dimming component, wherein the inner surface is the surface close to the human eye and the outer surface is the surface away from the human eye.

[0025] In some embodiments, the first surface of the first prism and the fifth surface of the second prism are curved surfaces, and the second surface, the third surface of the first prism, the fourth surface of the second prism, and the seventh surface of the third prism are all planar surfaces, and the second surface, the seventh surface, and the fourth surface are parallel to each other.

[0026] In some embodiments, the angle between the optical axis of the first surface of the first prism and the normal of the second surface ranges from 35° to 75°; the angle between the third surface and the second surface of the first prism ranges from 20° to 35°.

[0027] In some embodiments, the first surface and the fifth surface are spherical or aspherical.

[0028] In some embodiments, the eighth surface of the third prism is configured as a light-absorbing surface.

[0029] In some embodiments, the reflectivity r of the semi-transparent and semi-reflective beam splitter ranges from 5% to r ≤ 90%. According to another aspect of this disclosure, a wearable device is provided, comprising: a display screen and the aforementioned prism-folding near-eye display system, wherein the display screen is configured as an image source for the prism-folding near-eye display system.

[0030] Based on the embodiments of this disclosure, a prism-folding near-eye display system and a wearable device including the prism-folding near-eye display system are provided. The system includes an image source, a prism optical component constituting the folding display optical path, and a dimming component. The prism optical component includes at least one prism, a first waveplate, a polarizing beam splitter, and a semi-transparent, semi-reflective beam splitter. The dimming component is provided with a second waveplate, a first polarizing layer, a liquid crystal layer, and a second polarizing layer. It can modulate the polarization state of the light emitted from the display screen. Utilizing the polarization state conversion relationship between polarized light and the waveplate, polarizing beam splitter, semi-transparent, semi-reflective beam splitter, and dimming component, a portion of the light emitted from the image source can be directed into the user's eye. Furthermore, it can modulate the polarization state of external real-world light, modulating the intensity of the external real-world light to the user's desired intensity and directing it into the user's eye. This embodiment employs a prism structure to guide the path of display light. The dimming component can flexibly adjust the intensity of ambient light entering the user's eyes while absorbing the display light incident on the dimming component after passing through a semi-transparent, semi-reflective beam-splitting surface. This prevents leakage of display light emitted from the image source through the dimming component, allowing the user to simultaneously view both the image source and the actual external scene, thus protecting user privacy and minimizing impact on others. Furthermore, the system is compact, with smaller surface spacing between optical elements, eliminating the need for individual tilt angles for each element, resulting in greater space utilization and less light propagation loss, significantly improving the field of view while reducing the overall system thickness.

[0031] The technical solutions of this disclosure will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0032] The above and other objects, features, and advantages of this disclosure will become more apparent from the more detailed description of the embodiments thereof in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the disclosure and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps; Figure 1 This is a structural diagram of a prism-type near-eye display system provided in an exemplary embodiment of this disclosure; Figure 2A This is a schematic diagram of the liquid crystal molecule structure when no electric field is applied to the liquid crystal layer, provided by an exemplary embodiment of this disclosure; Figure 2B This is a schematic diagram of the liquid crystal molecule structure when an electric field is applied to the liquid crystal layer, provided by an exemplary embodiment of the present disclosure; Figure 3 This is a structural diagram of a prism-type near-eye display system provided in another exemplary embodiment of this disclosure; Figure 4 This is a structural diagram of a prism-type near-eye display system provided in another exemplary embodiment of this disclosure; Figure 5 This is a schematic diagram of two combinations of a first waveplate, a polarizing beam-splitting surface, a second waveplate, and a first polarizing layer provided in an exemplary embodiment of this disclosure; Figure 6 This is a structural diagram of a prism-type near-eye display system provided in yet another exemplary embodiment of this disclosure; Figure 7 This is a schematic diagram of two combinations of a first waveplate, a polarizing beam-splitting surface, a third waveplate, and a first polarizer provided in an exemplary embodiment of this disclosure; Figure 8 This is a structural diagram of a wearable device provided in an exemplary embodiment of this disclosure.

[0033] Figure label: 100 - Prism-type near-eye display system; 101 - Image source; 102 - First prism; 1021 - First surface; 1022 - Second surface; 1023 - Third surface; 103 - Second prism; 1031 - Fourth surface; 1032 - Fifth surface; 104 - Third prism; 1041 - Sixth surface; 1042 - Seventh surface; 1043 - Eighth surface; 105 - First waveplate; 106 - Polarizing beam splitter ; 107-Dimming component; 1071-Second waveplate; 1072-First polarizing layer; 1073-Liquid crystal layer; 1074-Second polarizing layer; 1075-First electrode layer; 1076-Second electrode layer; 1077-Antireflective coating; 1078-Structural support layer; 108-Fourth prism; 109-First polarizer; 110-Third waveplate; 111-Second polarizer; 800-Wearable device; 801-Display screen. Detailed Implementation

[0034] Hereinafter, exemplary embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present disclosure, and not all embodiments of the present disclosure, and it should be understood that the present disclosure is not limited to the exemplary embodiments described herein.

[0035] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this disclosure.

[0036] Those skilled in the art will understand that the terms "first," "second," etc., in the embodiments of this disclosure are only used to distinguish different steps, devices, or modules, and do not represent any specific technical meaning, nor do they indicate a necessary logical order between them.

[0037] It should also be understood that in the embodiments disclosed herein, "a plurality of" may refer to two or more, and "at least one" may refer to one, two or more.

[0038] It should also be understood that any component, data or structure mentioned in the embodiments of this disclosure can generally be understood as one or more unless expressly defined or given to the contrary in the context.

[0039] Furthermore, the term "and / or" in this disclosure is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this disclosure generally indicates that the preceding and following related objects have an "or" relationship.

[0040] It should also be understood that the description of the various embodiments in this disclosure emphasizes the differences between the various embodiments, and the similarities or similarities can be referred to each other. For the sake of brevity, they will not be described in detail.

[0041] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0042] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0043] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0044] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0045] SUMMARY Currently, among various types of AR glasses, those with a catadioptric structure (often called Birdbath) are widely used due to their excellent optical clarity and low optical distortion. Although catadioptric structures have significant advantages over other optical structures such as planar semi-transparent and semi-reflective structures, they still fall short of the needs of AR glasses product development. Specifically, AR glasses require a larger field of view (FOV) and a smaller size; however, current conventional catadioptric structures have a relatively small FOV, typically failing to reach 50°, and a relatively large thickness, usually greater than 15mm.

[0046] Current AR glasses typically lack transmittance adjustment capabilities, making it impossible to switch between non-transparent virtual immersive experiences and transparent mixed reality experiences, resulting in low user convenience. Furthermore, conventional AR glasses often suffer from light leakage, meaning that some imaging light leaks forward from the user's optical system, allowing others to see all or part of the virtual image being viewed from outside the glasses. This not only inconveniences others but also compromises the user's privacy. Therefore, how to enable AR glasses to both adjust transmittance and reduce or eliminate light leakage is a pressing issue that needs to be addressed.

[0047] Exemplary System Figure 1 An exemplary structural diagram of a prism-folding near-eye display system 100 according to an embodiment of the present disclosure is shown.

[0048] The prism-type near-eye display system 100 includes: an image source 101, a prism optical component constituting the folded-back display optical path, and a dimming component 107.

[0049] The image source 101 is used to emit display light. For example, the image source 101 can be a miniature display screen on which an image can be displayed.

[0050] The aforementioned prism optical assembly includes at least one prism, a first waveplate 105, a polarizing beam-splitting surface 106, and a semi-transparent, semi-reflective beam-splitting surface. The prism has an incident surface for receiving display light and a total internal reflection surface disposed inside the prism, configured to change the propagation direction of the display light after at least one total internal reflection within the prism. As an example, such as... Figure 1As shown, the at least one prism includes a first prism 102, a second prism 103, and a third prism 104. The first prism 102 includes a first surface 1021, a second surface 1022, and a third surface 1023. The second prism 103 includes a fourth surface 1031 and a fifth surface 1032. The third prism 104 includes a sixth surface 1041. Light rays passing through the first surface 1021 are incident on the second surface 1022, where total internal reflection occurs. A semi-transparent, semi-reflective coating may be provided on the fifth surface 1032, making it a semi-transparent, semi-reflective beam-splitting surface. Optionally, the reflectivity r of the semi-transparent, semi-reflective beam-splitting surface is in the range of 5% ≤ r ≤ 90%.

[0051] The aforementioned polarization beam splitter 106 includes a reflecting side and a transmitting side, configured to transmit incident light with a first polarization state and reflect light with a second polarization state different from the first polarization state. Specifically, the display light emitted by the image source 101 can be light with a second polarization state (s-polarized light), which is reflected by the polarization beam splitter 106 and propagates away from the human eye. Part of the reflected light from the downstream semi-transparent and semi-reflective beam splitter is modulated into light with a first polarization state (p-polarized light). This light, after entering the polarization beam splitter 106, can pass through the polarization beam splitter 106 and enter the human eye, forming a display light path, thus allowing the user to view the image from the image source 101.

[0052] In this embodiment, the first waveplate 105 is disposed on the reflecting side of the polarizing beam-splitting surface 106. The semi-transparent, semi-reflective beam-splitting surface is disposed downstream of the first waveplate 105 and is configured to partially reflect and partially transmit the incident light. For example... Figure 1 As shown, the display light, after total internal reflection on the second surface 1022, is incident on the polarization beam-splitting surface 106 via the third surface 1023 and is reflected by the polarization beam-splitting surface 106, propagating away from the human eye. The first waveplate 105 modulates the incident display light of the second polarization state. It should be understood that the first waveplate 105 in this embodiment can modulate the polarization state of polarized light received on either side. After partial reflection on the semi-transparent and semi-reflective beam-splitting surface (fifth surface 1032), the display light is again modulated by the polarization state of the first polarization state and is incident on the polarization beam-splitting surface 106. This light is transmitted by the polarization beam-splitting surface 106 and enters the human eye.

[0053] The type of the first wave plate 105 can be set according to actual needs, such as a quarter-wave plate or a half-wave plate. The position of the first wave plate 105 can also be set according to needs, for example, Figure 1 The first wave plate 105 shown is positioned between the first prism 102 and the second prism 103.

[0054] In this embodiment, the dimming component 107 is disposed on the transmission side of the semi-transparent and semi-reflective beam splitter; the dimming component 107 includes a second waveplate 1071, a first polarizing layer 1072, a liquid crystal layer 1073, and a second polarizing layer 1074 arranged sequentially along the transmission light path. The first waveplate 105, the second waveplate 1071, the polarizing beam splitter 106, and the first polarizing layer are arranged in a cooperative manner.

[0055] The dimming component 107 can isolate the prism optical component from the outside world and receive the ambient light entering from the outside. The portion of the transmitted light emitted from the semi-transparent and semi-reflective beam splitter continues to enter the dimming component 107, and the dimming component 107 can extinct part of the transmitted light so that some of the transmitted light will not pass through the dimming component 107 and be emitted out.

[0056] Specifically, such as Figure 1 The diagram shows a cross-sectional view of the dimming assembly 107. Along the transmission light path, the dimming assembly 107 is sequentially configured with a second waveplate 1071, a first polarizing layer 1072, a liquid crystal layer 1073, and a second polarizing layer 1074. The second waveplate 1071 modulates the polarization state of a portion of the transmitted light from the semi-transparent, semi-reflective beam splitter. The first polarizing layer 1072 blocks the transmission of the polarized light modulated by the second waveplate 1071. The second polarizing layer 1074 modulates the polarization state of external ambient light incident on the dimming assembly 107, allowing the liquid crystal layer 1073 to adjust the transmittance of the ambient ambient light.

[0057] like Figure 1 As shown, in order to flexibly control the transmittance of external ambient light, a first electrode layer 1075 and a second electrode layer 1076 can be disposed on both sides of the liquid crystal layer 1073. The liquid crystal layer 1073 is used to adjust the intensity of light transmitted from the outside through the dimming component 107 to the prism optical component under the action of the electric field generated between the first electrode layer 1075 and the second electrode layer 1076.

[0058] The method of adjusting the incident light intensity based on the liquid crystal layer 1073 can be achieved using various related technologies. Optionally, the type of liquid crystal layer 1073 includes, but is not limited to, any of the following: twisted nematic liquid crystal, liquid crystal with guest-host effect, liquid crystal with liquid crystal electro-controlled birefringence (ECB) characteristics, and Pi-cells liquid crystal.

[0059] The electric field strength generated between the first electrode layer 1075 and the second electrode layer 1076 can be manually adjusted by the user or automatically adjusted by the controller included in the system. For example, the system may also include a light intensity sensing device, which adjusts the electric field strength generated between the first electrode layer 1075 and the second electrode layer 1076 according to the magnitude of the external light intensity, so as to realize adaptive adjustment of the external light intensity entering the human eye.

[0060] The prism-type near-eye display system provided in this embodiment includes an image source, a prism optical component constituting the folding display optical path, and a dimming component. The prism optical component includes at least one prism, a first waveplate, a polarizing beam splitter, and a semi-transparent, semi-reflective beam splitter. The dimming component is provided with a second waveplate, a first polarizing layer, a liquid crystal layer, and a second polarizing layer. It can modulate the polarization state of the light emitted from the display screen. By utilizing the polarization state conversion relationship between polarized light and the waveplate, the polarizing beam splitter, the semi-transparent, semi-reflective beam splitter, and the dimming component, a portion of the light emitted from the image source can be directed into the user's eye. Furthermore, it can modulate the polarization state of external real-world light, modulating the intensity of the external real-world light to the user's desired intensity and directing it into the user's eye. This embodiment employs a prism structure to guide the path of display light. The dimming component can flexibly adjust the intensity of ambient light entering the user's eyes while absorbing the display light incident on the dimming component after passing through a semi-transparent, semi-reflective beam-splitting surface. This prevents leakage of display light emitted from the image source through the dimming component, allowing the user to simultaneously view both the image source and the actual external scene, thus protecting user privacy and minimizing impact on others. Furthermore, the system is compact, with smaller surface spacing between optical elements, eliminating the need for individual tilt angles for each element, resulting in greater space utilization and less light propagation loss, significantly improving the field of view while reducing the overall system thickness.

[0061] In some alternative implementations, the polarization direction of the first polarization layer 1072 is perpendicular to the polarization direction of the second polarization layer 1074.

[0062] The dimming component 107 structure provided in this embodiment includes a first polarization layer 1072 and a second polarization layer 1074, which can be combined with the polarization state of the liquid crystal layer 1073 under different electric field intensities to achieve adjustment of the intensity of external real-world light.

[0063] For example, this embodiment uses a twisted nematic liquid crystal (TN-LCD). The main function of a twisted nematic liquid crystal is to rotate the polarization direction of polarized light, and the rotation angle can be adjusted by the voltage applied to the electrodes on both sides. Figure 2A As shown, when no electric field is applied, the liquid crystal molecules twist and form a helical structure, which causes the polarization direction of polarized light passing through it to rotate by 90 degrees. Figure 2B As shown, when an electric field of a certain intensity is applied, the liquid crystal molecules are arranged parallel to the electric field, which has no effect on the polarization direction of the polarized light passing through them, and the polarized light maintains its original polarization state.

[0064] The polarization directions of the first polarizing layer 1072 and the second polarizing layer 1074 need to match those of the liquid crystal molecules, and the angle between the polarization directions of the two polarizing layers is the same as the rotation angle of the liquid crystal molecules when no voltage is applied.Figure 2A For example, when polarized light is rotated 90° after passing through the liquid crystal layer 1073, the polarization directions of the first polarization layer 1072 and the second polarization layer 1074 form a 90° angle. Unpolarized light becomes linearly polarized when passing through the second polarization layer 1074. This linearly polarized light is then modulated by the liquid crystal layer 1073, rotating its polarization direction by 90°, which aligns perfectly with the polarization direction of the first polarization layer 1072. The linearly polarized light then completely passes through the first polarization layer 1072. Under different electric field strengths, the linearly polarized light passes through the first polarization layer 1072 with different polarization directions, thus achieving different transmittances. Figure 2B For example, after applying a sufficient electric field, the liquid crystal molecules are arranged parallel to the electric field, which has no effect on the polarization direction of the polarized light passing through them. The polarized light passing through the second polarization layer 1074 maintains its original polarization state, and the polarization direction is at a 90° angle to the polarization direction of the first polarization layer 1072. The polarized light cannot pass through the first polarization layer 1072.

[0065] This embodiment sets the polarization direction of the first polarization layer 1072 and the polarization direction of the second polarization layer 1074 to be perpendicular to each other, and combines this with the polarization characteristics of the liquid crystal layer 1073 to achieve accurate control of the light intensity entering the human eye from the outside, thereby improving the system's adaptability to application scenarios.

[0066] In some alternative implementations, such as Figure 1 As shown, an antireflective film 1077 is provided on the inner and / or outer surfaces of the dimming assembly 107. The inner surface is the surface closest to the human eye, and the outer surface is the surface furthest from the human eye.

[0067] Optionally, to improve the mechanical strength of the outer lens, Figure 1 The dimming assembly 107 shown also includes a structural support layer 1078.

[0068] In this embodiment, by providing anti-reflection films on both surfaces of the dimming component 107, the proportion of light intensity transmitted through the dimming component 107 can be increased, and the degree of scattering on the surface of the dimming component 107 can be reduced. This helps to improve the clarity of the user's view of the external scene, and allows more light emitted from the image source 101 to enter the dimming component 107, reducing light leakage caused by scattering on the inner surface of the dimming component 107.

[0069] In some alternative implementations, at least one prism includes: a first prism 102, a second prism 103, and a third prism 104. The first prism 102 has a second surface 1022 that performs total internal reflection of the displayed light. The third surface 1023 of the first prism 102 and the sixth surface 1041 of the third prism 104 are bonded together, and a polarizing beam-splitting surface 106 is located between the bonded surfaces. The second prism 103 is located on the side of the first prism 102 closer to the second surface 1022.

[0070] like Figure 1 As shown, the first prism 102 includes a first surface 1021, a second surface 1022, and a third surface 1023; the second prism 103 includes a fourth surface 1031 and a fifth surface 1032; and the third prism 104 includes a sixth surface 1041. The incident angle of the light rays with the second surface 1022 is greater than the total internal reflection angle, resulting in total internal reflection at the second surface 1022. Optionally, a certain gap (e.g., greater than 0.01 mm) can be maintained between the second surface 1022 and the fourth surface 1031 to facilitate total internal reflection.

[0071] The polarization beam splitter 106 can be bonded between the third surface 1023 and the sixth surface 1041. The polarization beam splitter 106 can transmit specific types of polarized light (e.g., polarized light whose polarization state is parallel to the optical axis of the polarization beam splitter 106) and reflect another specific type of polarized light (e.g., polarized light whose polarization state is perpendicular to the optical axis). For example, the polarization beam splitter 106 can reflect s-polarized light and transmit p-polarized light. S-polarized and p-polarized light are common knowledge in the field of optics and will not be elaborated here. In this embodiment, the displayed light can be s-polarized light, which undergoes total internal reflection via the second surface 1022, then passes through the third surface 1023 and is incident on the polarization beam splitter 106, where it is reflected.

[0072] This embodiment achieves the transmission of light by multiple prisms and the implementation of polarization state modulation and beam splitting in the optical path between the prisms by setting a first prism 102, a second prism 103 and a third prism 104 in the prism optical assembly, and setting a polarization beam splitting surface 106 between the first prism 102 and the third prism 104. This improves the compactness of the system structure, helps to save the space occupied by the system, reduces the system thickness, and improves the field of view.

[0073] In some alternative implementations, a partially reflective film is provided on the side of the second prism 103 away from the first prism 102, forming a semi-transparent, semi-reflective beam-splitting surface. For example... Figure 1 As shown, the fifth surface 1032 of the second prism 103 is provided with a partial reflective film.

[0074] In this embodiment, by setting a partial reflective film on the side of the prism away from the first prism 102, a portion of the displayed light can be reflected to the human eye, while a portion of the external real-world light can be transmitted to the human eye. Combined with other optical components, the image displayed by the image source 101 and the external real-world light can be seen by the user at the same time, improving the stability of the system for AR display.

[0075] In some alternative implementations, such as Figure 3As shown, the system includes at least one prism and also includes a fourth prism 108 disposed between the second prism 103 and the dimming assembly 107. The refractive power of the fourth prism 108 cancels out the refractive power of the prism group composed of the first prism 102, the second prism 103 and the third prism 104.

[0076] Optionally, the fourth prism 108 is glued to the fifth surface 1032 of the second prism 103, or there is an air gap of a first preset width between the fourth prism 108 and the fifth surface 1032. The first preset width can be set according to actual needs. The glued method of the system structure can improve the stability of the system structure, while the air gap method can achieve more flexible configuration of the system structure.

[0077] Because the overall refractive power of the optical system composed of the first prism 102, the second prism 103, and the third prism 104 is usually not zero, the human eye will experience distortion when observing the external scene through the optical system composed of three prisms, making normal observation impossible. The fourth prism 108 is located on the side of the optical system composed of three prisms away from the human eye, and its refractive power is set so that it exactly cancels out the horizontal light transmission refractive power of the optical system composed of three prisms. This allows the human eye to observe the external scene normally after passing through all four prisms, improving the clarity of the user's view of the external scene.

[0078] In some alternative implementations, such as Figure 4 As shown, the system also includes a first polarizer 109 disposed on the light-emitting side of the image source 101. The first polarizer 109 is used to modulate the display light emitted from the image source 101 into first-type polarized light and incident it into the first prism 102. By disposing of the first polarizer 109, the polarization state of the display light can be modulated, and the desired polarized light can be incident into the prism optical components. Thus, based on the polarized light, the optical path of the display light can be effectively controlled, thereby improving the imaging quality and reducing light leakage.

[0079] Optionally, the first polarizer 109 is a linear polarizer. Correspondingly, the aforementioned first type of polarized light can be linearly polarized light, and can further be s-polarized light or p-polarized light. For example... Figure 4 As shown, the light incident on the first prism 102 is s-linearly polarized light. By setting the first polarizer 109 as a linear polarizer, the downstream optical elements can be configured based on the linearly polarized light, and the linearly polarized light can be controlled, which can improve the convenience of optical path control.

[0080] Optionally, a lens can be provided between the first polarizer 109 and the first prism 102. This lens is used to adjust the magnification, distortion parameters and other characteristics of the image displayed by the image source 101 in order to improve the imaging quality.

[0081] In some alternative implementations, the first waveplate 105 is positioned between the reflecting side of the polarizing beam-splitting surface 106 and the semi-transparent, semi-reflective beam-splitting surface. The specific position of the first waveplate 105 can be set according to the actual optical path. For example, as... Figure 4 As shown, the first waveplate 105 can be disposed between the second surface 1022 of the first prism 102 and the fourth surface 1031 of the second prism 103; as Figure 6 As shown, the first waveplate 105 is attached to the side of the polarization beam splitter 106 near the reflection side.

[0082] By placing the first waveplate 105 between the reflective side of the polarization beam splitter 106 and the semi-transparent and semi-reflective beam splitter, the polarization state of the light reflected by the polarization beam splitter 106 and the light reflected by the semi-transparent and semi-reflective beam splitter can be modulated, thereby controlling the propagation of light more effectively.

[0083] In some alternative implementations, the characteristics of the first waveplate 105, the polarizing beam-splitting surface 106, the second waveplate 1071, and the first polarizing layer 1072 can include any of the following combinations: Combination 1, along the direction of the displayed light (e.g., from...) Figure 4 (As shown in direction A), the fast axis of the first waveplate 105 is deflected clockwise by a preset angle relative to the optical transmission axis of the polarizing beam splitter 106; along the direction of the displayed light, the fast axis of the second waveplate 1071 is deflected clockwise by a preset angle relative to the extinction axis of the first polarizing layer 1072; the preset angle is in the range of 40° to 50°.

[0084] Combination 2: Along the direction of the displayed light, the fast axis of the first waveplate 105 is deflected counterclockwise by a preset angle relative to the optical transmission axis of the polarizing beam splitter 106; along the direction of the displayed light, the fast axis of the second waveplate 1071 is deflected counterclockwise by a preset angle relative to the extinction axis of the first polarizing layer 1072; the preset angle is in the range of 40° to 50°.

[0085] The preset angles mentioned above can be set according to the polarization state and the type of optical device required in the actual application scenario.

[0086] like Figure 5 As shown, a schematic diagram of the two combinations described above is presented. In this diagram, the optical axis indicated by QWP1 is the fast axis of the first waveplate 105, the optical axis indicated by PBS is the transmission axis of the polarization beam-splitting surface 106, the optical axis indicated by QWP2 is the fast axis of the second waveplate 1071, and the optical axis indicated by POL2 is the extinction axis of the first polarization layer 1072.

[0087] The following is combined Figure 4 Explain the working principle of combination one: In the combined mode, the s-polarized light reflected by the polarization beam splitter 106 is modulated by the first waveplate 105 to become left-handed polarized light c1. c1 is partially reflected by the fifth surface 1032 to become right-handed polarized light c2. c2 is modulated a second time by the first waveplate 105 to become p-polarized light. Since the polarization beam splitter 106 can transmit p-polarized light, this part of the light can pass through the polarization beam splitter 106 and the third prism 104 and enter the human eye smoothly to be perceived, allowing the human eye to see the image of the image source 101. The portion of c1 transmitted by the fifth surface 1032 is still left-handed light c1'. c1' is incident on the second waveplate 1071 on the dimming assembly 107. After being modulated by the second waveplate 1071, the left-handed light becomes linearly polarized light. Its polarization direction is 45° counterclockwise rotation of the fast axis of the second waveplate 1071 (viewed from direction A), which is exactly consistent with the extinction axis of the first polarization layer 1072. Therefore, it is absorbed by the first polarization layer 1072 and cannot propagate to the outside through the dimming assembly 107.

[0088] In the combined mode, ambient light enters the dimming component 107 from right to left. Since the extinction axis of the first polarizing layer 1072 is 45° counterclockwise from the fast axis of the second waveplate 1071 when viewed from direction A (that is, the light transmission axis of the first polarizing layer 1072 is 45° clockwise from the fast axis of the second waveplate 1071), the vibration direction of the linearly polarized light passing through the first polarizing layer 1072 is 45° clockwise from the fast axis of the first polarizing layer 1072 (when viewed from direction A). In this case, after being modulated by the first polarization layer 1072, the linearly polarized light becomes right-handed light. This right-handed light passes through the second prism 103 and is incident on the first waveplate 105. After being modulated by the first waveplate 105, it becomes linearly polarized light. Its vibration direction is 45° counterclockwise rotation of the fast axis of the first waveplate 105, which is the direction of the light transmission axis of the polarization beam splitter 106. Therefore, it can pass smoothly through the polarization beam splitter 106 and enter the human eye to be perceived, so that the human eye can see the external real-world light with the light transmittance adjusted.

[0089] The working principle of Combination 2 is explained below: In the second combination mode, the s-polarized light reflected by the polarization beam splitter 106 is modulated by the first waveplate 105 to become right-handed light c1. After being reflected by the fifth surface 1032, c1 becomes left-handed light c2. After being modulated a second time by the first waveplate 105, c2 becomes p-polarized light. Since the polarization beam splitter 106 can transmit p-polarized light, this part of the light can pass through the polarization beam splitter 106 and the third prism 104 and enter the human eye smoothly to be perceived, allowing the human eye to see the image of the image source 101. The portion of c1 transmitted by the fifth surface 1032 is still right-handed light c1'. c1' is incident on the second waveplate 1071 on the dimming assembly 107. After being modulated by the second waveplate 1071, the right-handed light becomes linearly polarized light. Its polarization direction is 45° clockwise rotation of the fast axis of the second waveplate 1071 (viewed from direction A), which is exactly consistent with the extinction axis of the first polarization layer 1072. Therefore, it is absorbed by the first polarization layer 1072 and cannot propagate to the outside through the dimming assembly 107.

[0090] In the second combination mode, ambient light enters the first polarizing layer 1072 on the dimming component 107 from right to left. Since the extinction axis of the first polarizing layer 1072 is 45° clockwise from the fast axis of the second waveplate 1071 when viewed from direction A (that is, the light transmission axis of the first polarizing layer 1072 is 45° counterclockwise from the fast axis of the second waveplate 1071), the vibration direction of the linearly polarized light passing through the first polarizing layer 1072 is 45° counterclockwise from the fast axis of the first polarizing layer 1072 (when viewed from direction A). In this case, after being modulated by the first polarization layer 1072, the linearly polarized light becomes left-handed light. This left-handed light passes through the second prism 103 and is incident on the first waveplate 105. After being modulated by the first waveplate 105, it becomes linearly polarized light. Its vibration direction is 45° clockwise rotation of the fast axis of the first waveplate 105, which is the direction of the light transmission axis of the polarization beam splitter 106. Therefore, it can pass smoothly through the polarization beam splitter 106 and enter the human eye to be perceived, so that the human eye can see the external real scene light modulated by the light transmittance.

[0091] The combination of the two optical elements provided in this embodiment enables more flexible control over the polarization state of light, and allows for richer implementation methods to eliminate image light emitted from the display screen on the dimming component 107 while transmitting real-scene light to the human eye. This facilitates more flexible selection of optical devices and improves the adaptability to application scenarios.

[0092] In some optional implementations, the first waveplate 105 is a quarter-wave plate; the second waveplate 1071 is a quarter-wave plate. A quarter-wave plate can convert linearly polarized light incident upon it into circularly polarized or elliptically polarized light, or convert circularly polarized or elliptically polarized light into linearly polarized light. When used in conjunction with a linear polarizer, it allows for flexible control of the transmission of polarized light.

[0093] In some alternative implementations, the first waveplate 105 is attached to the optical surface of the second prism 103 near the first prism 102.

[0094] like Figure 4 As shown, the first waveplate 105 can be disposed between the second surface 1022 of the first prism 102 and the fourth surface 1031 of the second prism 103, and can be attached to the fourth surface 1031. The first waveplate 105 is used to modulate the first type of polarized light reflected by the polarization beam-splitting surface 106 into second type of polarized light. The second type of polarized light can be circularly polarized light or elliptically polarized light. Figure 4 As shown, the s-polarized light entering through the first surface 1021 undergoes total internal reflection at the second surface 1022, and then passes through the polarization beam splitter 106. The s-polarized light is reflected to the first waveplate 105, which modulates the s-polarized light into circularly polarized light c1, which is the second type of polarized light.

[0095] After the second type of polarized light is partially reflected by the fifth surface 1032, the partially reflected light passes through the first wave plate 105 and is modulated into third type polarized light. The third type of polarized light passes through the second surface 1022 and the polarization beam splitter 106, is transmitted into the third prism 104, and is further incident into the human eye.

[0096] After passing through the first waveplate 105, the reflected light is modulated again into third-type polarized light, which corresponds to the type of transmitted light of the polarization beam splitter 106. For example, if the polarization beam splitter 106 can transmit p-polarized light, then part of the reflected light is modulated into p-polarized light by the first waveplate 105. Figure 5 The first waveplate 105 shown can be a quarter-wave plate, which modulates the s-light into left-handed light c1. After being reflected by the fifth surface 1032, the left-handed light c1 becomes right-handed light c2. After being modulated by the first waveplate 105, the right-handed light c2 becomes p-polarized light, and then the p-polarized light can pass through the polarization beam splitter 106.

[0097] In this embodiment, by attaching the first waveplate 105 to the optical surface of the second prism 103 near the first prism 102, the first waveplate 105 and the polarization beam-splitting surface 106 can be combined. This allows the polarization beam-splitting surface 106 to reflect the image light emitted from the image source 101 and transmit the light reflected back from the semi-transparent and semi-reflective beam-splitting surface. At the same time, the polarization state of the light incident on the dimming component 107 can be set to a specific type, which facilitates the first polarization layer 1072 on the dimming component 107 to extinct the polarized light incident therein, thereby promoting more stable image display and preventing light leakage.

[0098] In some alternative implementations, such as Figure 1As shown, there is an air gap of a second preset width between the first wave plate 105 and the second surface 1022 of the first prism 102.

[0099] Optionally, the second preset width is greater than or equal to 0.01 mm.

[0100] By setting an air gap of a certain width between the first wave plate 105 and the second surface 1022 of the first prism 102, it can be ensured that the display light undergoes total internal reflection on the second surface 1022, thus preventing the display light from leaking from the second surface 1022.

[0101] In some alternative implementations, the first waveplate 105 is attached to the side of the polarizing beam-splitting surface 106 closest to the reflecting side. For example... Figure 6 As shown, the first waveplate 105 is disposed between the polarizing beam splitter 106 and the third surface 1023 of the first prism 102, and is in contact with the polarizing beam splitter 106 and the third surface 1023.

[0102] The system also includes a third waveplate 110 disposed between the first polarizer 109 and the prism optical assembly. For example... Figure 6 As shown, a third waveplate 110 is disposed between the first polarizer 109 and the first prism 102. Optionally, the first waveplate 105 is a quarter-wave plate, and the third waveplate 110 is a quarter-wave plate. A quarter-wave plate can convert linearly polarized light incident upon it into circularly polarized light or elliptically polarized light, or convert circularly polarized light or elliptically polarized light into linearly polarized light. When used in conjunction with a linear polarizer, the transmission of polarized light can be flexibly controlled.

[0103] The first polarizer 109 described above can modulate the display light emitted from the image source 101 into first-type polarized light. For example, the first polarizer 109 is a linear polarizer, which can modulate the display light into s-polarized light or p-polarized light.

[0104] The third waveplate 110 is used to modulate the first type of polarized light into second type polarized light, which is then incident on the first prism 102. If the third waveplate 110 is a quarter-wave plate, the second type of polarized light can be circularly polarized or elliptically polarized. Figure 6 As shown, the first type of polarized light is s-linearly polarized light. After being modulated by the third waveplate 110, it forms circularly polarized light c1. c1 passes through the first surface 1021 and enters the first prism 102.

[0105] In this embodiment, after the second type of polarized light undergoes total internal reflection on the second surface 1022, it passes through the first waveplate 105 and is modulated into first type of polarized light. The first type of polarized light is reflected back to the first waveplate 105 by the polarization beam splitter 106, modulated into second type of polarized light, and incident into the second prism 103.

[0106] like Figure 6 As shown, circularly polarized light c1 (second type polarized light) undergoes total internal reflection on the second surface 1022. The reflected light c1' is still circularly polarized light, but the trajectory of the light vector vibration changes (e.g., from left-handed to right-handed). After passing through the first waveplate 105, c1' is modulated into s-polarized light. The s-polarized light is reflected back to the first waveplate 105 by the polarization beam splitter 106. The first waveplate 105 modulates the s-polarized light into circularly polarized light c2, which is also second type polarized light.

[0107] After partial reflection by the fifth surface 1032, the second type of polarized light passes through the second surface 1022 and the first wave plate 105 and is modulated into third type polarized light. The third type of polarized light passes through the polarization beam splitter 106, is transmitted into the third prism 104 and enters the human eye.

[0108] like Figure 6 As shown, circularly polarized light c2 is partially reflected at the fifth surface 1032, and the reflected light is c3, which is still circularly polarized light. c3 passes through the first waveplate 105 and becomes p-linearly polarized light (third type polarized light), and then the p-linearly polarized light can pass through the polarization beam splitter 106.

[0109] This embodiment provides more combinations of optical elements such as polarizers, waveplates between prisms, and polarization beam-splitting surface 106. By setting a third waveplate 110 and placing the first waveplate 105 on the side of the polarization beam-splitting surface 106 closer to the reflection side, the optical structure is made more compact, which facilitates improved stability. At the same time, it further enriches the implementation methods of the prism-flipped near-eye display system, allowing for flexible selection of optical components and improving the system's adaptability to different scenarios.

[0110] In some alternative implementations, the characteristics of the first waveplate 105, the polarizing beam-splitting surface 106, the third waveplate 110, and the first polarizer 109 can include any of the following combinations: Combination 3, along the direction of the displayed light (such as...) Figure 6 (As shown in direction A), the fast axis of the first waveplate 105 is deflected counterclockwise by a preset angle relative to the optical axis of the polarizing beam splitter 106; along the direction of the displayed light (such as... Figure 6 (As shown in direction B), the fast axis of the third waveplate 110 is deflected counterclockwise by a preset angle relative to the optical axis of the first polarizer 109; the preset angle is in the range of 40° to 50°.

[0111] Combination 4, along the direction of the displayed light (such as...) Figure 6 (As shown in direction A), the fast axis of the first waveplate 105 is deflected clockwise by a preset angle relative to the optical axis of the polarizing beam splitter 106; along the direction of the displayed light (such as...) Figure 6(As shown in direction B), the fast axis of the third waveplate 110 is deflected clockwise by a preset angle relative to the optical axis of the first polarizer 109; the preset angle is in the range of 40° to 50°.

[0112] like Figure 7 The diagram illustrates the two combinations described above. In this diagram, QWP1 indicates the fast axis of the first waveplate 105, PBS indicates the transmission axis of the polarizing beam splitter 106, QWP3 indicates the fast axis of the third waveplate 110, and POL1 indicates the transmission axis of the first polarizer 109. The optical axis positional relationship between the second waveplate 1071 and the first polarizing layer 1072 corresponding to combination three is shown below. Figure 6 In Assembly 1, QWP2 and POL2 have the same positional relationship. In Assembly 4, the optical axis positional relationship between the second waveplate 1071 and the first polarizing layer 1072 is the same as... Figure 6 In the second combination shown, QWP2 and POL2 have the same positional relationship.

[0113] The following is combined Figure 6 Explain the working principle of combination three: In the combined three-mode configuration, viewed from direction B, the display light emitted from image source 101 becomes linearly polarized light after passing through the first polarizer 109. After being modulated by the third waveplate 110, it becomes left-handed polarized light c1. Left-handed polarized light c1 is reflected by the second surface 1022 and becomes right-handed polarized light c1'. Right-handed polarized light c1' is incident on the first waveplate 105 and modulated by the first waveplate 105 into s-polarized light, which is then reflected to the right by the polarization beam splitter 106. The s-polarized light is modulated again by the first waveplate 105 and becomes left-handed polarized light c2. c2 is partially reflected by the fifth surface 1032 and becomes right-handed polarized light c3. After being modulated a second time by the first waveplate 105, c3 becomes p-polarized light. Since the polarization beam splitter 106 can transmit p-polarized light, this part of the light can pass through the polarization beam splitter 106 and the third prism 104 and enter the human eye smoothly for perception, allowing the human eye to see the image from image source 101. The portion of c2 transmitted by the fifth surface 1032 is still left-handed light c2'. c2' is incident on the second waveplate 1071 on the dimming assembly 107. After being modulated by the second waveplate 1071, the left-handed light becomes linearly polarized light. Its polarization direction is 45° counterclockwise rotation of the fast axis of the second waveplate 1071 (viewed from direction A), which is exactly in line with the extinction axis of the first polarization layer 1072. Therefore, it is absorbed by the first polarization layer 1072 and cannot propagate to the outside through the dimming assembly 107.

[0114] In the combination of the three modes, the propagation process of external real-world light entering the dimming component 107 is the same as that described in the combination of the one modes, and will not be repeated here.

[0115] The working principle of Combination Four is explained below: In the combined four-mode configuration, viewed from direction B, the display light emitted from image source 101 becomes linearly polarized light after passing through the first polarizer 109. After being modulated by the third waveplate 110, it becomes right-handed polarized light c1. After being reflected by the second surface 1022, right-handed polarized light c1 becomes left-handed polarized light c1'. Left-handed polarized light c1' is incident on the first waveplate 105 and modulated by it into s-polarized light, which is then reflected to the right by the polarization beam splitter 106. The s-polarized light is modulated again by the first waveplate 105 and becomes right-handed polarized light c2. After being partially reflected by the fifth surface 1032, c2 becomes left-handed polarized light c3. After being modulated a second time by the first waveplate 105, c3 becomes p-polarized light. Since the polarization beam splitter 106 can transmit p-polarized light, this part of the light can pass through the polarization beam splitter 106 and the third prism 104 and enter the human eye smoothly to be perceived, allowing the human eye to see the image on the display screen. The portion of c2 transmitted by the fifth surface 1032 is still right-handed light c2'. c2' is incident on the second waveplate 1071 on the dimming assembly 107. After being modulated by the second waveplate 1071, the right-handed light becomes linearly polarized light. Its polarization direction is 45° clockwise rotation of the fast axis of the second waveplate 1071 (viewed from direction A), which is exactly consistent with the extinction axis of the first polarization layer 1072. Therefore, it is absorbed by the first polarization layer 1072 and cannot propagate to the outside through the dimming assembly 107.

[0116] In the fourth combination mode, the propagation process of external real-world light entering the dimming component 107 is the same as the propagation process described in the second combination mode above, and will not be repeated here.

[0117] The combination of the two optical elements provided in this embodiment enables more flexible control over the polarization state of light, and allows for richer implementation methods to eliminate the display light emitted by the image source 101 on the dimming component 107, while transmitting real-scene light to the human eye. This helps to further select optical devices more flexibly and further improve the adaptability of application scenarios.

[0118] In some alternative implementations, the system further includes a second polarizer 111 disposed on the transmission side of the polarization beam splitter 106, wherein the polarization direction of the second polarizer 111 is set to be consistent with the transmission polarization direction of the polarization beam splitter 106.

[0119] like Figure 4 and Figure 6 As shown, a second polarizer 111 is disposed between the polarizing beam splitter 106 and the sixth surface 1041 of the third prism 104. The polarization direction of the second polarizer 111 is set to be consistent with the transmission polarization direction of the polarizing beam splitter 106, so that the light transmitted through the polarizing beam splitter 106 passes through the second polarizer 111.

[0120] Optionally, the second polarizer 111 is a linear polarizer, that is, the second polarizer 111 allows linearly polarized light with a polarization direction parallel to its optical axis to pass through, and blocks linearly polarized light with a polarization direction perpendicular to the optical axis from passing through.

[0121] In this embodiment, the partially reflected light, after being reflected by the fifth surface 1032, re-enters the first prism 102 and then enters the polarization beam-splitting surface 106. Since the polarization state of the partially reflected light is modulated by the first waveplate 105, the polarization beam-splitting surface 106 will allow some of the reflected light to be transmitted (for example, transmitting p-polarized light and reflecting s-polarized light). The polarization direction of the second polarizer 111 is consistent with the polarization direction of the light transmitted through the polarization beam-splitting surface 106. Therefore, the light can be transmitted through the second polarizer 111 and enter the human eye.

[0122] In addition, the second polarizer 111 can significantly reduce ambient stray light that is incident from the sides of each prism and reflected by the polarizing beam splitter 106 into the human eye, thereby allowing the display light to enter the human eye while reducing the impact of ambient light on the viewing of the image source 101.

[0123] In some alternative implementations, such as Figure 1 As shown, the first surface 1021 of the first prism 102 and the fifth surface 1032 of the second prism 103 are curved surfaces. Optionally, the first surface 1021 and the fifth surface 1032 are spherical or aspherical. When designing the curvature of the curved surface, the curvature can be set in conjunction with the system's magnification, distortion parameters, refractive power, and other indicators of the display screen image to ensure that the system meets the imaging requirements.

[0124] like Figure 1 As shown, the second surface 1022 and the third surface 1023 of the first prism 102, the fourth surface 1031 of the second prism 103, and the seventh surface 1042 of the third prism 104 are all planes, and the second surface 1022, the seventh surface 1042 and the fourth surface 1031 are parallel to each other.

[0125] Setting each of the above surfaces as planes, and making certain planes parallel to each other, facilitates the combined installation of prisms, and makes it easier to set up optical films such as polarizing beam splitters and polarizers between prisms, thereby reducing the distortion of light propagating between prisms and improving the efficiency of system installation and the stability of use.

[0126] In some alternative implementations, the angle between the optical axis of the first surface 1021 of the first prism 102 and the normal of the second surface 1022 is in the range of 35°-75°; the angle between the third surface 1023 and the second surface 1022 of the first prism 102 is in the range of 20°-35°.

[0127] The aforementioned angle range ensures the performance of the optical system composed of each prism and allows for flexible adjustment of the overall system thickness, improving the flexibility of system design and manufacturing.

[0128] In some alternative implementations, the eighth surface 1043 of the third prism 104 is set as a light-absorbing surface.

[0129] like Figure 1 As shown, the eighth surface 1043 is the lower side of the third prism 104. The light-absorbing surface can be achieved in various ways, such as by frosting and / or blackening, to reduce stray light entering the prism assembly and light leakage in the optical system, further protecting user privacy and improving the imaging quality of the optical system.

[0130] The following is for reference. Figure 8 This diagram illustrates the structure of a wearable device 800 according to an embodiment of the present disclosure. The wearable device can be any of various devices used for near-eye display, such as augmented reality glasses, virtual reality glasses, etc. The wearable device includes a display screen 801 and the aforementioned prism-folding near-eye display system 100. The light-emitting surface of the display screen 801 is perpendicular to the incident optical axis of the prism assembly in the prism-folding near-eye display system 100, and the display light emitted by the display screen 801 enters the prism assembly. The display screen is configured as an image source for the prism-folding near-eye display system 100.

[0131] Optionally, the wearable device may also include components such as a power supply, a controller, and a manual control panel to support the wearable device in achieving more functions.

[0132] The wearable device provided in the above embodiments of this disclosure, by using the aforementioned prism-refracting near-eye display system, allows users to simultaneously view the display screen image and the actual external scene while preventing screen image leakage, thus helping to protect user privacy and avoid impacting others. Furthermore, by using the aforementioned prism-refracting near-eye display system, the wearable device significantly improves the field of view while reducing the overall thickness of the glasses, enhancing user convenience.

[0133] The basic principles of this disclosure have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details for implementation.

[0134] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For system embodiments, since they largely correspond to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0135] The block diagrams of devices, apparatuses, devices, and systems disclosed herein are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0136] The methods and apparatus of this disclosure may be implemented in many ways. For example, they may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order of steps for the methods is for illustrative purposes only, and the steps of the methods of this disclosure are not limited to the order specifically described above unless otherwise specifically stated. Furthermore, in some embodiments, this disclosure may also be implemented as a program recorded on a recording medium, the program including machine-readable instructions for implementing the methods according to this disclosure. Thus, this disclosure also covers recording media storing programs for performing the methods according to this disclosure.

[0137] It should also be noted that in the apparatus, devices, and methods of this disclosure, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions to this disclosure.

[0138] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0139] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this disclosure to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A prism-based near-eye display system, characterized in that, include: Image source, used to emit display light; A prism optical assembly constituting the optical path of a folded-back display; the prism optical assembly includes at least one prism, a first waveplate, a polarizing beam-splitting surface, and a semi-transparent, semi-reflective beam-splitting surface. The prism has an incident surface for receiving the display light and a total reflection surface disposed inside the prism, the total reflection surface being configured to cause the display light to change its propagation direction after undergoing at least one total reflection inside the prism. The polarization beam-splitting surface includes a reflecting side and a transmitting side, and is configured to transmit light rays with a first polarization state in the incident light and reflect light rays with a second polarization state different from the first polarization state. The first waveplate is disposed on the reflecting side of the polarization beam splitter, and the semi-transparent and semi-reflective beam splitter is disposed downstream of the first waveplate and is configured to partially reflect and partially transmit the incident light. A dimming component is disposed on the transmission side of the semi-transparent and semi-reflective beam splitter; the dimming component includes a second waveplate, a first polarizing layer, a liquid crystal layer and a second polarizing layer arranged sequentially along the transmission light path, wherein the first waveplate, the second waveplate, the polarizing beam splitter and the first polarizing layer are arranged in cooperation with each other.

2. The system according to claim 1, wherein, The at least one prism includes: a first prism, a second prism, and a third prism. The first prism has a second surface that allows total internal reflection of the displayed light. The third surface of the first prism and the sixth surface of the third prism are bonded to each other, and the polarizing beam-splitting surface is located between the bonded surfaces. The second prism is located on the side of the first prism closer to the second surface.

3. The system according to claim 2, wherein, A partial reflective film is provided on the side of the second prism away from the first prism, forming the semi-transparent and semi-reflective beam-splitting surface.

4. The system according to claim 2, wherein, The at least one prism further includes a fourth prism disposed between the second prism and the dimming component, wherein the refractive power of the fourth prism cancels out the refractive power of the prism group consisting of the first prism, the second prism, and the third prism.

5. The system according to claim 4, wherein, The fourth prism is bonded to the fifth surface of the second prism, or there is an air gap of a first preset width between the fourth prism and the fifth surface.

6. The system according to claim 1, wherein, The system further includes a first polarizer disposed on the light-emitting side of the image source.

7. The system according to claim 6, wherein, The first polarizer is a linear polarizer.

8. The system according to claim 2, wherein, The first waveplate is disposed between the reflective side of the polarization beam splitter and the semi-transparent and semi-reflective beam splitter.

9. The system according to claim 8, wherein, Along the direction of the displayed light, the fast axis of the first waveplate is deflected clockwise by a predetermined angle relative to the transmission axis of the polarizing beam splitter; along the direction of the displayed light, the fast axis of the second waveplate is deflected clockwise by a predetermined angle relative to the extinction axis of the first polarizing layer; the predetermined angle is in the range of 40° to 50°; or Along the direction of the displayed light, the fast axis of the first waveplate is deflected counterclockwise by a preset angle relative to the transmission axis of the polarizing beam splitter; along the direction of the displayed light, the fast axis of the second waveplate is deflected counterclockwise by a preset angle relative to the extinction axis of the first polarizing layer; the preset angle is in the range of 40° to 50°.

10. The system according to claim 8, wherein, The first waveplate is a quarter-wave plate; the second waveplate is a quarter-wave plate.

11. The system according to claim 8, wherein, The first waveplate is attached to the optical surface of the second prism near the first prism.

12. The system according to claim 8, wherein, There is an air gap of a second preset width between the first waveplate and the second surface of the first prism.

13. The system according to claim 12, wherein, The second preset width is greater than or equal to 0.01 mm.

14. The system according to claim 6, wherein, The first waveplate is attached to the side of the polarizing beam splitter near the reflection side, and the system further includes a third waveplate disposed between the first polarizer and the prism optical assembly.

15. The system according to claim 14, wherein, Along the direction of the displayed light, the fast axis of the first waveplate is deflected counterclockwise by a predetermined angle relative to the optical axis of the polarizing beam splitter; along the direction of the displayed light, the fast axis of the third waveplate is deflected counterclockwise by a predetermined angle relative to the optical axis of the first polarizer; the predetermined angle is in the range of 40° to 50°; or Along the direction of the displayed light, the fast axis of the first waveplate is deflected clockwise by a preset angle relative to the optical axis of the polarizing beam splitter; along the direction of the displayed light, the fast axis of the third waveplate is deflected clockwise by a preset angle relative to the optical axis of the first polarizer; the preset angle is in the range of 40° to 50°.

16. The system according to claim 14, wherein, The first waveplate is a quarter-wave plate, and the third waveplate is a quarter-wave plate.

17. The system according to claim 1, wherein, The system further includes a second polarizer disposed on the transmission side of the polarization beam splitter, wherein the polarization direction of the second polarizer is set to be consistent with the transmission polarization direction of the polarization beam splitter.

18. The system according to any one of claims 1 to 17, wherein, The polarization direction of the first polarization layer is perpendicular to the polarization direction of the second polarization layer.

19. The system according to claim 18, wherein, The liquid crystal layer is of any one of the following types: twisted nematic liquid crystal, liquid crystal with guest-host effect characteristics, liquid crystal with electrically controlled birefringence characteristics, and Pi-cells liquid crystal.

20. The system according to claim 18, wherein, An antireflective film is provided on the inner and / or outer surfaces of the dimming component, wherein the inner surface is the surface close to the human eye and the outer surface is the surface away from the human eye.

21. The system according to claim 2, wherein, The first surface of the first prism and the fifth surface of the second prism are curved surfaces, and the second surface, the third surface of the first prism, the fourth surface of the second prism, and the seventh surface of the third prism are all planar surfaces, and the second surface, the seventh surface, and the fourth surface are parallel to each other.

22. The system according to claim 21, wherein, The angle between the optical axis of the first surface of the first prism and the normal of the second surface ranges from 35° to 75°. The included angle between the third surface and the second surface of the first prism is in the range of 20°-35°.

23. The system according to claim 21, wherein, The first surface and the fifth surface are either spherical or aspherical.

24. The system according to claim 21, wherein, The eighth surface of the third prism is set as a light-absorbing surface.

25. The system according to any one of claims 1 to 17, wherein, The reflectivity r of the semi-transparent and semi-reflective beam splitter is in the range of 5% ≤ r ≤ 90%.

26. A wearable device, comprising: The display screen and the prism-reflective near-eye display system according to any one of claims 1-25, wherein the display screen is configured as an image source for the prism-reflective near-eye display system.

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