Virtual reality equipment

Abstract

The utility model provides a virtual reality device. The virtual reality equipment comprises a display module, a first quarter-wave plate, a semi-reflecting and semi-transmitting Fresnel lens, a second quarter-wave plate, a reflective polarizer and a transparent base material which are sequentially arranged along a light path and are mutually matched and connected, the first quarter-wave plate is attached to the light emitting face of the display module, the threaded face of the semi-reflecting and semi-transmitting Fresnel lens is tightly stacked on the first quarter-wave plate, and air layers are reserved between threads on the threaded face. The second quarter-wave plate is connected with the surface, deviating from the threaded surface, of the semi-reflecting and semi-transmitting Fresnel lens; and the reflective polaroid is attached to the transparent base material. According to the scheme, the virtual reality equipment adopts the semi-reflective semi-transparent Fresnel lens, so that the production yield is improved, the overall production cost is reduced, the assembly process is simple, the production period is shortened, the light reflection loss is reduced, and the light utilization rate is improved through the air layer design.

Description

TECHNICAL FIELD

[0001] The utility model relates to display technical field, especially relate to a virtual reality device. BACKGROUND

[0002] The existing folding light path scheme (such as pancake) is mostly based on the lens design of aspheric surface, and no matter single-piece, double-piece or three-piece scheme, the film material specification requirement is extremely high. This not only increases the material procurement cost, and in the process of bonding process, due to the strict requirement on process precision, leads to low yield. High scrap rate further pushes up the production cost, makes the virtual reality (VR) product price high, leads to the high cost of VR product, seriously hinders the large-scale promotion and popularization of VR technology.

[0003] On the other hand, the manufacturing and bonding process of aspheric lens is complex, and needs high-precision equipment and professional technicians to operate. Complex process not only increases the production cycle, but also improves the management difficulty and error risk in the production process, which is not conducive to large-scale and efficient production. SUMMARY

[0004] The utility model embodiment provides a virtual reality device to solve the problem of the production cost in prior art due to low yield, and solve the problem of low efficiency in prior art due to long production cycle and management difficulty and error risk of virtual reality device.

[0005] In order to solve the above technical problems, the utility model adopts the following technical scheme:

[0006] The utility model embodiment provides a virtual reality device, comprising:

[0007] Display module, first quarter wave plate, half reflection half transmission Fresnel lens, second quarter wave plate, reflective polarizer and transparent substrate are sequentially arranged along the light path and are connected with each other.

[0008] The first quarter wave plate is attached to the light exit surface of the display module, and the threaded surface of the half reflection half transmission Fresnel lens is tightly stacked on the first quarter wave plate, and an air layer is reserved between the threads on the threaded surface.

[0009] The second quarter wave plate is connected with the surface of the half reflection half transmission Fresnel lens away from the threaded surface.

[0010] The reflective polarizer is attached to the transparent substrate.

[0011] Optionally, a half reflection half transmission film layer is plated on the threaded surface of the half reflection half transmission Fresnel lens.

[0012] Optionally, the second quarter-wave plate is attached to a surface of the half-reflection half-transmission Fresnel lens facing away from the threaded surface, or is attached to a surface of the reflective polarizer facing the half-reflection half-transmission Fresnel lens.

[0013] Optionally, a surface of the half-reflection half-transmission Fresnel lens facing away from the threaded surface faces the second quarter-wave plate, and the half-reflection half-transmission Fresnel lens and the second quarter-wave plate are kept in close optical attachment.

[0014] Optionally, the second quarter-wave plate 4 and the half-reflection half-transmission Fresnel lens 3 are attached by optical glue, and the optical glue has an optical refractive index matched with the second quarter-wave plate and the half-reflection half-transmission Fresnel lens.

[0015] Optionally, edges of the first quarter-wave plate, the half-reflection half-transmission Fresnel lens, the second quarter-wave plate, the reflective polarizer, and the transparent substrate are sealed and connected by a sealing strip.

[0016] Optionally, connection interfaces between the display module and the first quarter-wave plate, between the half-reflection half-transmission Fresnel lens and the second quarter-wave plate, and between the reflective polarizer and the transparent substrate are respectively surfaces subjected to anti-reflection treatment.

[0017] The present application has the following beneficial effects:

[0018] In the scheme of the present application, the half-reflection half-transmission Fresnel lens is used to reduce the material and attachment difficulty, and compared with the aspherical lens, the structure of the Fresnel lens is simpler, and the specification requirement of the material in the manufacturing process is relatively not so harsh. The threaded structure can be manufactured by relatively mature processes such as injection molding, and does not need to use high-specification film materials like the aspherical lens, thereby reducing the material procurement cost. When the threaded surface of the half-reflection half-transmission Fresnel lens cooperates with the first quarter-wave plate, only close stacking is needed, and the assembly method has a relatively low requirement on the attachment precision. Compared with the complex attachment process of the aspherical lens, the probability of generating waste products due to precision problems in the attachment process is reduced, the yield of the product is improved, and the production cost is reduced.

[0019] In the scheme of the present application, the connection mode of the components of the entire device is relatively simple, such as that the first quarter-wave plate is attached to the light-emitting surface of the display module, and the reflective polarizer is attached to the transparent substrate. These attachment processes are relatively common and mature in the optical field. Compared with the complex manufacturing and attachment process of the aspherical lens, the possibility of generating waste products due to the complex process is reduced, the production yield is improved, and the cost is reduced.

[0020] This application also leverages the advantages of Fresnel lens manufacturing, and the relatively mature and standardized manufacturing processes for components such as the first quarter-wave plate, second quarter-wave plate, and reflective polarizer. Large-scale production can improve efficiency and further shorten the production cycle. The assembly process for each component of the equipment is relatively simple, requiring relatively low levels of professional skills from operators. Unlike the manufacturing and bonding of aspherical lenses, it does not rely on high-precision equipment and complex operations by specialized technicians, thus reducing the management difficulty in the production process. Attached Figure Description

[0021] Figure 1 This is a schematic diagram showing the structure of the virtual reality device provided in an embodiment of the present invention. Detailed Implementation

[0022] To make the technical problems, technical solutions, and advantages of this utility model clearer, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments. In the following description, specific details such as particular configurations and components are provided merely to aid in a comprehensive understanding of the embodiments of this utility model. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this utility model. Furthermore, for clarity and brevity, descriptions of known functions and structures have been omitted.

[0023] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the present invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0024] This utility model addresses at least one of the following problems in the prior art: the increased production costs due to low yield rates, and the low efficiency caused by long production cycles, management difficulties, and high error risks in the prior art of virtual reality devices. It provides a virtual reality device.

[0025] Reference Figure 1 As shown, this application embodiment provides a virtual reality device, including:

[0026] The display module 1, the first quarter-wave plate 2, the semi-reflective Fresnel lens 3, the second quarter-wave plate 4, the reflective polarizer 5, and the transparent substrate 6 are arranged sequentially and connected to each other along the optical path.

[0027] The first quarter-wave plate 2 is attached to the light exit surface of the display module 1, and the threaded surface of the semi-reflective semi-transmissive Fresnel lens 3 is closely stacked on the first quarter-wave plate 2, and an air layer is reserved between the threads on the threaded surface;

[0028] The second quarter-wave plate 4 is connected to the surface of the semi-reflective semi-transmissive Fresnel lens 3 away from the threaded surface; here, the surface of the semi-reflective semi-transmissive Fresnel lens 3 away from the threaded surface can also be understood as the reflecting surface of the semi-reflective semi-transmissive Fresnel lens 3;

[0029] The reflective polarizer 5 is attached to the transparent substrate 6.

[0030] In the embodiments of the present application, the display module 1 can be a liquid crystal display (LCD), for example, a 2.5K resolution (2560x1440) LCD screen can be selected, with a refresh rate of 90Hz, which can provide clear and smooth image display. The outgoing light is P light in linearly polarized light, and this polarization characteristic is the basis for subsequent optical processing. The model of the display module 1 above is only illustrative. The first quarter-wave plate 2 and the second quarter-wave plate 4 are made of birefringent crystal material (such as quartz) 1 / 4 wave plate. Optionally, the thickness is 0.5mm, which ensures accurate conversion of the polarization state of light. The lens material of the semi-reflective semi-transmissive Fresnel lens 3 is selected from optical plastics (such as PMMA) and is manufactured by injection molding process. The threaded surface is coated with a semi-reflective semi-transmissive film layer to achieve 50% reflectivity and 50% transmittance.

[0031] Optionally, the thread spacing is designed to be 0.2mm, the thread depth is 0.1mm, and the curvature radius is optimized according to the required magnification and field of view to make it equivalent to a concave mirror when viewed from the plane side, which can magnify the folded light path. The reflective polarizer 5 can be selected from a multi-layer polymer reflective polarizer with a polarization degree greater than 99%. It can efficiently reflect linearly polarized S light while allowing linearly polarized P light to pass through. For example, the thickness of the reflective polarizer 5 is 0.2mm, which ensures good polarization selection performance without adding too much thickness. The transparent substrate 6 uses optical glass as the transparent substrate, and the thickness is optionally 2mm, which has high transparency (transmittance greater than 92%) and good mechanical properties. The surface of the transparent substrate is polished to ensure that the light can pass through without loss, and finally a clear image is presented to the user.

[0032] Specifically, the optical imaging principle of the virtual reality device is based on the regulation, reflection and transmission of the polarization state of light by each optical element, as well as the special optical properties of the semi-reflective semi-transmissive Fresnel lens, ultimately realizing imaging. Among them, the display module 1 is the light source of the entire imaging system, which outputs light containing image information. These light rays usually have a specific polarization state, for example, they can be linearly polarized light, whose vibration direction is fixed in a certain plane. The light rays are emitted from the light-emitting surface of the display module 1 and enter the subsequent optical elements.

[0033] The first quarter-wave plate 2 is attached to the light-emitting surface of the display module 1, and the polarization state will change when the light passes through it. The quarter-wave plate has birefringent properties and can produce a quarter-wave phase difference between two mutually perpendicular polarization components. If the incident light is linearly polarized light, it will be converted into circularly polarized light after passing through the first quarter-wave plate 2. The electric field vector endpoint of circularly polarized light makes circular motion in the plane perpendicular to the propagation direction, which is divided into left-handed circularly polarized light and right-handed circularly polarized light, depending on the relative relationship between the vibration direction of linearly polarized light and the fast axis and slow axis of the wave plate.

[0034] The threaded surface of the semi-reflective semi-transmissive Fresnel lens 3 is closely stacked on the first quarter-wave plate 2, and air layers are reserved between the threads. When the circularly polarized light reaches the semi-reflective semi-transmissive Fresnel lens 3, part of the light will be reflected and part of the light will be transmitted. This semi-reflective semi-transmissive property allows light to reflect and propagate multiple times inside the lens, achieving light path folding, thereby increasing the path length of light propagation in a limited space, which helps to reduce the overall size of the device.

[0035] The air layer between the threads plays an important role. Due to the difference in refractive index between air and lens material, the use of this refractive index difference can reduce the reflection loss of light on the lens surface, improve the transmittance of light, ensure that more light can participate in imaging, and enhance the brightness of the image.

[0036] The threaded structure of the Fresnel lens is similar to that of a traditional convex lens, which can focus light. By reasonably designing the parameters of the threads, such as thread spacing and depth, the light can be focused to a specific location, thereby forming a clear image in the subsequent imaging process.

[0037] The light transmitted through the semi-reflective semi-transmissive Fresnel lens 3 continues to propagate and reaches the second quarter-wave plate 4. The second quarter-wave plate 4 is connected to the surface of the semi-reflective semi-transmissive Fresnel lens 3 away from the threaded surface, which will adjust the polarization state of the light again. At this time, the circularly polarized light is converted back to linearly polarized light after passing through the second quarter-wave plate 4, but the vibration direction may be different from the initial linearly polarized light emitted by the display module.

[0038] The reflective polarizer 5 has the characteristics of selectively reflecting and transmitting light of a certain polarization direction. When linearly polarized light converted by the second quarter-wave plate 4 reaches the reflective polarizer 5, only light with a vibration direction consistent with the polarization direction allowed to be transmitted by the reflective polarizer can be transmitted, and light with other polarization directions will be reflected back. Through this screening effect, the reflective polarizer 5 can improve the contrast and clarity of the image and reduce the interference of stray light.

[0039] Finally, the light transmitted through the reflective polarizer 5 passes through the transparent substrate 6 attached thereto. The transparent substrate 6 usually has high transparency and good optical performance, and it plays a role in protecting the reflective polarizer 5 and making the light propagate uniformly. After being processed by a series of optical elements, the light finally exits from the transparent substrate 6, enters the human eye or other imaging receiving devices, and forms a clear image with certain contrast and brightness, thereby realizing the optical imaging function of the virtual reality device.

[0040] The scheme of the present application effectively controls the propagation and intensity of light through multiple polarization state conversions and the action of the semi-reflective semi-transmissive Fresnel lens, and improves the contrast and clarity of the image. The magnification effect of the semi-reflective semi-transmissive Fresnel lens increases the field of view, allowing users to experience the virtual scene more comprehensively. The folding light path design realizes a longer light path in a limited space through multiple reflections and refractions, thereby reducing the thickness and weight of the device and improving the comfort of wearing. The semi-reflective semi-transmissive Fresnel lens uses injection molding process and optical plastic material, which reduces the material cost and manufacturing difficulty compared with traditional aspherical lenses, and improves the production efficiency and yield.

[0041] Optionally, a semi-reflective semi-transmissive film layer is coated on the threaded surface of the semi-reflective semi-transmissive Fresnel lens 3.

[0042] In the present application, the threaded surface of the semi-reflective semi-transmissive Fresnel lens 3 is coated with a film, and the appropriate coating material is selected according to the required semi-reflective semi-transmissive optical performance. Optionally, such as a combination of metal (such as aluminum, silver, etc.) and dielectric material (such as silicon dioxide, titanium dioxide, etc.). The metal material can provide a certain reflectivity, while the dielectric material helps to adjust the transmittance and optimize the optical performance. For example, a semi-reflective semi-transmissive film layer is coated on the threaded surface of the semi-reflective semi-transmissive Fresnel lens by physical vapor deposition or chemical vapor deposition process. During the coating process, the deposition rate, thickness and uniformity of the coating material are precisely controlled to achieve the required reflectivity and transmittance (for example, 50% reflection, 50% transmission). By adjusting the coating parameters, the optical performance can be optimized according to different application requirements.

[0043] Optionally, the second quarter-wave plate 4 is attached to the surface of the half reflective half-transmissive Fresnel lens 3 away from the threaded surface, or to the surface of the reflective polarizer 5 facing the half reflective half-transmissive Fresnel lens 3.

[0044] In the embodiments of the present application, the second quarter-wave plate 4 and the surface of the half reflective half-transmissive Fresnel lens 3 away from the threaded surface are cleaned to remove dust, oil stains and other impurities on the surface, so as to ensure the cleanliness of the attached surface. In a clean environment, the second quarter-wave plate 4 is accurately attached to the corresponding surface of the half reflective half-transmissive Fresnel lens 3 using an attaching device. Optical glue can be used for attachment, and attention should be paid to avoid bubbles and impurities during the attachment process. Vacuum attachment can be used to improve the attachment quality.

[0045] In the embodiments of the present application, the second quarter-wave plate 4 and the surface of the half reflective half-transmissive Fresnel lens 3 away from the threaded surface are cleaned to remove dust, oil stains and other impurities on the surface, so as to ensure the cleanliness of the attached surface. In a clean environment, the second quarter-wave plate 4 is accurately attached to the corresponding surface of the half reflective half-transmissive Fresnel lens 3 using an attaching device. Optical glue can be used for attachment, and attention should be paid to avoid bubbles and impurities during the attachment process. Vacuum attachment can be used to improve the attachment quality.

[0046] Optionally, the surface of the half reflective half-transmissive Fresnel lens away from the threaded surface faces the second quarter-wave plate, and the half reflective half-transmissive Fresnel lens and the second quarter-wave plate are in close optical attachment.

[0047] In the embodiments of the present application, according to the refraction law of light, when light enters from one medium to another medium, refraction occurs, and the refraction angle is related to the refractive index of the two media. In the case of close attachment of the half reflective half-transmissive Fresnel lens 3 and the second quarter-wave plate 4, light can be approximately regarded as propagating in a continuous optical medium. Since the refractive indices of the two are relatively stable and the attachment is close, the refraction behavior of light at the interface can be accurately predicted and controlled, thereby effectively adjusting the propagation direction and polarization state of light. The second quarter-wave plate 4 converts the polarization state of light through its birefringent characteristics. When light enters the second quarter-wave plate 4 at a suitable angle and polarization state, the plate will cause a specific phase difference between the two perpendicular polarization components of light, thereby changing the polarization state of light. Close attachment can ensure that light enters the second quarter-wave plate in the correct state, making the polarization state conversion more accurate and reliable, meeting the requirements of the optical design of the entire virtual reality device.

[0048] On the other hand, the close optical bonding makes the distance between the surface molecules of the semi-reflective semi-transmissive Fresnel lens 3 and the second quarter-wave plate 4 close enough to generate strong intermolecular forces. These intermolecular forces tightly bind the two together, forming a stable connection structure. This connection not only ensures the fixed relative position between the two, but also reduces the slight displacement and shaking caused by external factors, ensuring the stability and reliability of the optical system.

[0049] The close optical bonding connection of the present application can minimize the reflection and scattering of light at the interface between the semi-reflective semi-transmissive Fresnel lens and the second quarter-wave plate. When light enters from one medium to another, if there is an air gap or unevenness at the interface, part of the light will be reflected or scattered in other directions, reducing the transmittance of the light. Close bonding allows the light to pass more smoothly through the interface, ensuring that more light can participate in subsequent optical processes, improving the brightness and imaging quality of the entire virtual reality device. The role of the second quarter-wave plate is to further adjust the polarization state of the light that has passed through the semi-reflective semi-transmissive Fresnel lens. Close bonding ensures that the change in polarization state is more stable and accurate during the propagation of light from the semi-reflective semi-transmissive Fresnel lens to the second quarter-wave plate. This helps to achieve more precise polarization state control, so that the light that finally reaches the human eye has appropriate polarization characteristics, thereby improving the contrast and color saturation of the image, allowing the user to see clearer and more vivid virtual images.

[0050] Optionally, the second quarter-wave plate 4 and the semi-reflective semi-transmissive Fresnel lens 3 are bonded and connected by optical glue, and the optical glue has an optical refractive index that matches the second quarter-wave plate and the semi-reflective semi-transmissive Fresnel lens.

[0051] In the embodiments of the present application, when light propagates from one medium to another, due to the difference in refractive index of the two media, reflection occurs at the interface, following the Fresnel reflection law. If the second quarter-wave plate and the semi-reflective semi-transmissive Fresnel lens are in direct contact, the difference in refractive index between them will cause part of the light to be reflected at the interface, resulting in light loss and reducing the efficiency and imaging quality of the entire optical system. By using optical glue with a matching optical refractive index for bonding, the refractive index between the media is similar when the light passes from the semi-reflective semi-transmissive Fresnel lens into the optical glue and then from the optical glue into the second quarter-wave plate. The reflectivity at the interface is greatly reduced. In this way, more light can smoothly pass through the interface and continue to propagate, improving the transmittance of the light and ensuring the brightness and clarity of the image.

[0052] The main function of the second quarter-wave plate is to precisely adjust the polarization state of the light. If the light is reflected and scattered at the interface between the half-reflective half-transmissive Fresnel lens and the second quarter-wave plate, the propagation direction and polarization state of the light will be disturbed, affecting the accuracy of the polarization state adjustment by the second quarter-wave plate. When using an index-matched optical adhesive, the propagation of the light at the interface is closer to that in a single homogeneous medium, reducing the disturbance to the propagation characteristics of the light, ensuring that the second quarter-wave plate can accurately convert the polarization state of the light as designed, and thus ensuring that the polarization control function of the entire optical system can be normally performed.

[0053] Optionally, the edges of the first quarter-wave plate 2, the half-reflective half-transmissive Fresnel lens 3, the second quarter-wave plate 4, the reflective polarizer 5, and the transparent substrate 6 are sealed and connected by a sealing strip.

[0054] In this application, the sealing strip acts as a barrier to prevent dust and other impurities from entering the gaps of the components and adhering to the surface of the optical elements to interfere with the propagation of light, ensuring clear imaging. It also prevents external moisture from entering, avoiding the expansion, deformation, or destruction of the film layer of the optical material, prolonging the service life of the element and stabilizing the optical performance. This application also uses the sealing strip to fix the relative positions of the optical components, preventing displacement caused by vibration and ensuring that the light propagates along the designed path to maintain stable imaging quality. It blocks external stray light from entering the system, reducing interference with the imaging light and improving image contrast and clarity.

[0055] Optionally, the connecting interfaces between the display module 1 and the first quarter-wave plate 2, the half-reflective half-transmissive Fresnel lens 3 and the second quarter-wave plate 4, and the reflective polarizer 5 and the transparent substrate 6 are respectively anti-reflection treated surfaces.

[0056] In the embodiments of this application, when the light propagates at different medium interfaces, it will be reflected due to the difference in refractive index, resulting in energy loss and degradation of imaging quality. The anti-reflection treated connecting interface reduces the reflectivity of the interface through special film layers or surface structures, allowing more light to pass through and improving the light utilization rate and imaging brightness of the optical system. Stray light produced by interface reflection will scatter within the optical system, forming glare or ghost images, affecting the clarity and contrast of the image. Anti-reflection treatment reduces reflected light and reduces the generation of stray light, making the image clearer and purer and improving the visual experience. In different environments, the reflectivity of untreated interfaces may change with temperature, humidity, etc. Anti-reflection treatment stabilizes the reflectivity of the connecting interface, ensuring consistent performance of the optical system under different conditions and stable and reliable imaging quality.

[0057] In one specific embodiment, the first quarter-wave plate 2 is attached to the display module 1. This connection method ensures that light emitted from the display module 1 can directly and efficiently enter the first quarter-wave plate 2 for polarization conversion. The tight attachment can reduce light scattering and energy loss during propagation, and also ensures the relative position stability between the first quarter-wave plate 2 and the display module 1, avoiding the impact of positional changes on the polarization conversion effect of the light.

[0058] The threaded surfaces of the semi-reflective Fresnel lens 3 are tightly stacked on the first quarter-wave plate 2, with an air layer remaining between the threads. This connection method not only ensures a tight fit between the two to allow light to smoothly enter the semi-reflective Fresnel lens 3 from the first quarter-wave plate 2, but also strictly controls the air layer between the threads. If the air layer is filled with glue or other substances, it will disrupt the special optical structure formed by the air and the lens material, causing the Fresnel lens to lose its effect of reducing reflection loss and adjusting the direction of light propagation.

[0059] The second quarter-wave plate 4 has two attachment options: it can be attached to the opposite side of the semi-reflective Fresnel lens 3 relative to the first quarter-wave plate 2, or it can be attached to the reflective polarizer 5. Regardless of the attachment method, a tight fit between the second quarter-wave plate 4 and adjacent devices must be ensured to guarantee accurate polarization conversion of light during propagation. Furthermore, different attachment methods may affect the propagation path and polarization conversion effect of light, requiring selection and optimization based on the specific optical design.

[0060] The reflective polarizer 5 is attached to the transparent substrate 6, which provides physical support and protection for the reflective polarizer 5. The attachment process must ensure uniform and tight adhesion between the two, avoiding air bubbles or impurities, to ensure that light can pass through the transparent substrate 6 and the reflective polarizer 5 without obstruction, ultimately achieving a clear imaging effect.

[0061] Specifically, refer to Figure 1 The structure shown illustrates that module 1 emits linearly polarized P-beams, which are then converted to left-handed polarization by the first quarter-wave plate 2. This left-handed polarized light then passes through a semi-reflective Fresnel lens 3, where its intensity is reduced to 50%, but it remains left-handed. This left-handed light then passes through a second quarter-wave plate 4, becoming linearly polarized S-beams. It is reflected by a reflective polarizer 5, then converted back to left-handed polarization by the second quarter-wave plate 4, and then reflected again by the semi-reflective Fresnel lens 3, where its intensity decreases by 25% and becomes right-handed. It then passes through the second quarter-wave plate 4 again, becoming linearly polarized P-beams, and passes through the reflective polarizer 5 and the transparent substrate 6 to form a magnified virtual image. Because the threaded surface of the semi-reflective Fresnel lens 3 is coated with a semi-reflective film, it appears as a concave mirror when viewed from the planar side, thus magnifying the image during light reflection. Through this process, the light path is folded, resulting in an equivalent light path structure with a greater object distance.

[0062] The application provides a virtual reality device based on a single-piece folded light path of a Fresnel lens, all surfaces needing optical bonding in the virtual reality device are planar structures, and the virtual reality device is very easy to bond and process.

[0063] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0064] In addition, the terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0065] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or can communicate with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0066] In the present application, unless otherwise specifically defined and limited, the "upper" or "lower" of the first feature in the second feature can include the direct contact of the first and second features, or can include the contact of the first and second features through another feature between them. Moreover, the "upper", "upper" and "upper" of the first feature in the second feature include the vertical direction of the first feature above and obliquely above the second feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature in the second feature include the vertical direction of the first feature below and obliquely below the second feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0067] The above is the preferred embodiment of the present application, it should be pointed out that for the ordinary person in the art without departing from the principles described in the present application under the premise can be made several improvements and refinements, these improvements and refinements are also within the scope of the present application.

Claims

1. A virtual reality device, characterized by, The application relates to a display module, which comprises a display module, a first quarter-wave plate, a half-reflection and half-transmission Fresnel lens, a second quarter-wave plate, a reflective polarizer and a transparent substrate. The first quarter-wave plate is attached to the light-out surface of the display module, and the threaded surface of the half-reflection and half-transmission Fresnel lens is closely stacked on the first quarter-wave plate, and an air layer is reserved between the threads on the threaded surface. The second quarter-wave plate is connected with the surface of the half-reflection and half-transmission Fresnel lens which is away from the threaded surface. The reflective polarizer is attached to the transparent substrate. The threaded surface of the half-reflection and half-transmission Fresnel lens is coated with a half-reflection and half-transmission film layer.

2. The virtual reality device of claim 1, wherein, The second quarter-wave plate is attached to the surface of the half-reflection and half-transmission Fresnel lens which is away from the threaded surface, or to the surface of the reflective polarizer which faces the half-reflection and half-transmission Fresnel lens.

3. The virtual reality device of claim 1, wherein, The surface of the half-reflection and half-transmission Fresnel lens which is away from the threaded surface faces the second quarter-wave plate, and the half-reflection and half-transmission Fresnel lens and the second quarter-wave plate are closely and optically attached.

4. The virtual reality device of claim 1, wherein, The second quarter-wave plate and the half-reflection and half-transmission Fresnel lens are attached by optical glue, and the optical glue has an optical refractive index which matches the second quarter-wave plate and the half-reflection and half-transmission Fresnel lens.

5. The virtual reality device of claim 1, wherein, The edges of the first quarter-wave plate, the half-reflection and half-transmission Fresnel lens, the second quarter-wave plate, the reflective polarizer and the transparent substrate are sealed and connected by sealing rubber strips.

6. The virtual reality device of claim 1, wherein, The connecting interfaces between the display module and the first quarter-wave plate, between the half-reflection and half-transmission Fresnel lens and the second quarter-wave plate, and between the reflective polarizer and the transparent substrate are respectively anti-reflection treated surfaces.

7. The virtual reality device of claim 1, wherein, ​

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