A VR device

Abstract

The application discloses a VR device, which comprises an optical system, the optical system comprising a lens module and an aperture; the lens module comprising a fixed-focus lens assembly and an electrically variable liquid lens arranged on the same optical axis; the side of the fixed-focus lens assembly away from the liquid lens being an object side, the side of the liquid lens away from the fixed-focus lens assembly being an image side; the aperture being located on the side of the fixed-focus lens assembly away from the liquid lens and arranged on the same optical axis with the lens module; wherein the liquid lens has a liquid lens curvature film with variable curvature, the liquid lens curvature film being capable of changing its curvature based on electric field control; the curvature of the liquid lens curvature film being related to the object distance of the optical system; the object distance being the distance between the aperture and a virtual image formed. The device adopts the electrically variable liquid lens to realize focal length adjustment, and the zooming speed is fast and the zooming process is free of motor noise.

Description

Technical Field

[0001] This application relates to the field of optical equipment technology, and more specifically, to a VR device. Background Technology

[0002] Currently, zooming in VR devices typically utilizes mechanical zoom display technology. The zoom principle involves using image processing to locate the pupil center coordinates, calculating the user's gaze point using a built-in algorithm, and then using a motor and gear module to drive a beam splitter to achieve zooming, enabling real-time changes in multiple degrees of freedom between the lens and the gaze point. However, the drawbacks of motor-driven gear zooming are also apparent: the noise from the motor driving the gears is significant, and the zooming speed is slow, severely impacting the user experience. Summary of the Invention

[0003] In view of this, this application provides a VR device, the solution of which is as follows: The device includes:

[0004] An optical system, comprising a lens module and an aperture;

[0005] The lens module includes a fixed-focus lens assembly and an electrically zoomable liquid lens arranged on the same optical axis; the side of the fixed-focus lens assembly facing away from the liquid lens is the object side, and the side of the liquid lens facing away from the fixed-focus lens assembly is the image side.

[0006] The aperture is located on the side of the fixed-focus lens assembly away from the liquid lens and is coaxial with the lens module;

[0007] The liquid lens contains a liquid lens curvature film with variable curvature, which can change its curvature based on an electric field control. The curvature of the liquid lens curvature film is related to the object distance of the optical system. The object distance is the distance between the aperture and the formed virtual image.

[0008] Preferably, in the above-described device, when the liquid lens curvature film is convex in the direction from the object side to the image side, the curvature of the liquid lens curvature film is greater than +88; when the liquid lens curvature film is concave, the curvature of the liquid lens curvature film is less than -88.

[0009] Preferably, in the above-described device, the fixed-focus lens assembly includes: a first lens and a second lens;

[0010] The first lens and the second lens have the same refractive index range.

[0011] Preferably, in the above-described device, the refractive index range of the first lens and the second lens is 1.49 to 1.8.

[0012] Preferably, in the above-described device, both the first lens and the second lens are plastic lenses.

[0013] Preferably, in the above-described device, the object-side surface of the first lens is convex, and the image-side surface is planar;

[0014] The object-side surface of the second lens is convex, and the image-side surface is concave.

[0015] Preferably, in the above-described device, the image-side surface of the first lens has a linear polarizing film, a polarizing beam splitter film, and a quarter-wave plate film.

[0016] The image-side surface of the second lens has a semi-transparent and semi-reflective coating.

[0017] Preferably, in the above-described device, the first lens and the second lens have the same range of dispersion coefficients;

[0018] The dispersion coefficients of the first lens and the second lens range from 18 to 60.

[0019] Preferably, in the above-described device, the length of the optical system ranges from 32mm to 40mm.

[0020] Preferably, in the above-mentioned device, the effective focal length of the optical system is in the range of 23mm to 27mm.

[0021] Preferably, in the above-described device, the device further includes:

[0022] The display panel fixed to the image side of the transparent module;

[0023] Alternatively, the image side of the lens module may have a mounting structure for detachably placing the display panel.

[0024] As described above, this application proposes a VR device, comprising: an optical system including a lens module and an aperture; the lens module including a fixed-focus lens assembly and an electrically zoomable liquid lens arranged coaxially; the side of the fixed-focus lens assembly facing away from the liquid lens is the object side, and the side of the liquid lens facing away from the fixed-focus lens assembly is the image side; the aperture is located on the side of the fixed-focus lens assembly facing away from the liquid lens and is coaxial with the lens module; wherein, the liquid lens has a curvature-variable liquid lens curvature film, the curvature of which can be changed based on an electric field control; the curvature of the liquid lens curvature film is related to the object distance of the optical system; the object distance is the distance between the aperture and the formed virtual image. The liquid lens curvature film changes its curvature based on an electric field control, so that the curvature of the liquid lens curvature film changes based on the object distance of the optical system, thereby achieving a zoom effect. The device uses an electrically zoom liquid lens to adjust the focal length, eliminating the need for a motor, thus reducing the device's size along the optical axis. Furthermore, it offers fast zooming speeds and eliminates motor noise during the zooming process. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0026] The structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0027] Figure 1 This is a schematic diagram of the structure of a VR device according to this application;

[0028] Figure 2 This is a schematic diagram of the structure of the VR device when the object distance of the liquid lens in this application is -500mm;

[0029] Figure 3 This is a schematic diagram of the structure of the VR device when the object distance of the liquid lens in this application is -4000mm;

[0030] Figure 4 This is a schematic diagram of the structure of another VR device in this application;

[0031] Figure 5 This is a diagram showing the structural parameters of the optical system in this application;

[0032] Figure 6 This is a diagram showing the aspherical coefficient distribution of the lens assembly in this application;

[0033] Figure 7 The MTF plot of the optical system is shown when the object distance of the liquid lens in this application is -4000mm.

[0034] Figure 8 The MTF diagram of the optical system is shown when the object distance of the liquid lens in this application is -500mm.

[0035] Figure 9 The MTF plot of the optical system is shown when the object distance of the liquid lens in this application is -250mm.

[0036] Figure 10 This is a relative illumination diagram of the optical system in this application;

[0037] Figure 11 This is a schematic diagram of the field curvature of the optical system in this application;

[0038] Figure 12 This is a schematic diagram of the distortion of the optical system in this application. Detailed Implementation

[0039] The embodiments of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0040] Currently, zoom functionality in existing VR technology is based on mechanical variable focal length display (MVS) technology. MVS is the mainstream zoom solution in VR devices at present, offering advantages over other technologies such as electronic zoom liquid crystal lenses, including lower cost, higher maturity, and a wider field of view. MVS technology controls the distance between the lenses and the screen by using a gear module to drive the reciprocating linear motion of a focusing motor. It employs a precision gear transmission module to adjust the distance between the two lens components of the VR / AR eye until it matches the user's interpupillary distance. Combined with eye tracking, foveated rendering, and other hardware and software technologies, it simulates the refractive and binocular convergence processes that occur when the human eye observes objects at different distances, thereby achieving clear visual imaging.

[0041] Mechanical zoom display technology uses a gear module to drive focusing. During the focusing process, the rotation of the gears and the operation of the motor will generate noise. In addition, the zoom speed based on the gear module to drive focusing also needs to be improved. These problems will affect the user experience.

[0042] To address the aforementioned issues, this application proposes a VR device comprising an electrically zoomable liquid lens. The liquid lens alters its curvature based on an electric field, causing the curvature to change according to its object distance, thereby achieving a zoom effect. The object distance is the distance between the aperture and the formed virtual image. This device utilizes an electrically zoomable liquid lens for focal length adjustment, eliminating the need for a motor, thus reducing the device's size along the optical axis. Furthermore, it offers fast zooming speeds and eliminates motor noise during the zooming process.

[0043] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a VR device according to this application. The VR device includes:

[0045] Optical system 1, which includes lens module 2 and aperture 3;

[0046] The lens module 2 includes a fixed-focus lens assembly 21 and an electrically zoomable liquid lens 22 arranged on the same optical axis; the side of the fixed-focus lens assembly 21 facing away from the liquid lens 22 is the object side, and the side of the liquid lens 22 facing away from the fixed-focus lens assembly 21 is the image side.

[0047] The aperture 3 is located on the side of the fixed-focus lens assembly 21 away from the liquid lens 22, and is coaxial with the lens module 2;

[0048] The liquid lens 22 contains a liquid lens curvature film 221 with variable curvature, which can change its curvature based on electric field control. The curvature of the liquid lens curvature film 221 is related to the object distance of the optical system 1. The object distance is the distance between the aperture 3 and the formed virtual image.

[0049] refer to Figure 1The VR device described in this application includes an optical system 1, which includes a lens module 2 and an aperture 3. The lens module 2 includes a fixed-focus lens assembly 21 and a liquid lens 22. The aperture number (F#) of the aperture 3 in the optical system 1 ranges from 6.07 to 6.66. The maximum image height in the optical system 1 is 19.2 mm. The wavelength in the optical system 1 is set to 0.540 μm, where the resolution of the optical system 1 is relatively good at this wavelength. In the optical system 1, the liquid lens 22 includes a liquid lens curvature film 221. Under the action of an external electric field, the curvature of the liquid lens curvature film 221 changes. The curvature of the liquid lens curvature film 221 can change based on the change in the object distance of the optical system 1. That is, in the VR device, when the object distance of the optical system 1 changes, the curvature of the liquid lens curvature film 221 also changes accordingly, thereby achieving a zoom effect. The device zooms through an external electric field, resulting in no motor vibration or noise during zooming, and the zoom speed is also relatively fast. Furthermore, the liquid lens 22 used for zooming occupies a small area, has a fast response time, is less susceptible to external damage, and helps extend its service life.

[0050] In the device, when the liquid lens curvature film 221 is convex in the direction from the object side to the image side, the curvature of the liquid lens curvature film 221 is greater than +88; when the liquid lens curvature film 221 is concave, the curvature of the liquid lens curvature film 221 is less than -88.

[0051] Based on the above, in the VR device, the liquid lens 22 includes a liquid lens curvature film 221. The curvature of the liquid lens curvature film 221 can vary based on the object distance of the optical system 1; that is, the curvature and convexity of the liquid lens curvature film 221 are determined by the object distance of the optical system 1. Based on the above, in the direction from the object side to the image side, when the liquid lens curvature film 221 is convex, its curvature is greater than +88; when the liquid lens curvature film 221 is concave, its curvature is less than -88.

[0052] refer to Figure 1 In the device, the fixed-focus lens assembly 21 includes: a first lens 211 and a second lens 212;

[0053] The first lens 211 and the second lens 212 have the same refractive index range.

[0054] refer to Figure 1The device includes the optical system 1, which includes the lens module 2. The lens module 2 includes a fixed-focus lens assembly 21, wherein the fixed-focus lens assembly 21 includes a first lens 211 and a second lens 212. The first lens 211 is located on the object side of the second lens 212, and the second lens 212 is located on the object side of the liquid lens 22. The first lens 211 and the second lens 212 have the same refractive index range. The refractive index refers to the ratio of the sine of the incident angle to the sine of the refraction angle after light is refracted through the lens, and the refractive index of the lens is affected by factors such as the lens material.

[0055] In the device, the refractive index of the first lens 211 and the second lens 212 is in the range of 1.49 to 1.8.

[0056] As described above, the refractive indices of the first lens 211 and the second lens 212 have the same range, while their values ​​range from 1.49 to 1.8. Although the refractive indices of the first lens 211 and the second lens 212 have the same range, their individual values ​​can differ. Furthermore, the material and focal length range of the first lens 211 and the second lens 212 can be determined based on their refractive index ranges.

[0057] In the device, both the first lens 211 and the second lens 212 are plastic lenses.

[0058] In the device described in this embodiment, both the first lens 211 and the second lens 212 are plastic lenses, and the first lens 211 is made of EP8000 material; the second lens 212 is made of OPtimas7500 material. The main reasons for using plastic lenses in this application are their light weight, suitability for mass production, and the fact that they are formed by injection molding, making them easy to manufacture. Furthermore, while facilitating imaging, they can also effectively reduce production costs.

[0059] refer to Figure 1 In the device, the object-side surface R11 of the first lens 211 is convex, and the image-side surface R12 is flat.

[0060] The object-side surface R21 of the second lens 212 is convex, and the image-side surface R22 is concave.

[0061] refer to Figure 1In the device described in this embodiment, the first lens 211 is a crescent-shaped lens, meaning its object-side surface R11 is convex and its image-side surface R12 is flat, with a radius of curvature of +101.926 mm for the object-side surface R11; the equivalent focal length f1 of the first lens 211 is 152.15 mm. The distance CT1 between the geometric center of the optical axis of the object-side surface R11 and the geometric center of the optical axis of the image-side surface R12 of the first lens 211 is 2.8 mm, meaning the thickness CT1 of the first lens 211 is 2.8 mm. The second lens 212 has a convex object-side surface R21 with a radius of curvature of +754.302 mm and a concave image-side surface R22 with a radius of curvature of -93.787 mm; the equivalent focal length f2 of the second lens 212 is 216.4 mm. The distance CT2 between the geometric center of the optical axis of the object side R21 of the second lens 212 and the geometric center of the optical axis of its image side R22 is 3.214 mm, meaning the thickness CT2 of the second lens 212 is 3.214 mm. The distance DT1 between the geometric center of the optical axis of the image side R12 of the first lens 211 and the geometric center of the optical axis of the object side R21 of the second lens 212 is 2.908 mm, meaning the distance DT1 between the first lens 211 and the second lens 212 is 2.908 mm.

[0062] refer to Figure 1 In the device, the image side R12 of the first lens 211 is covered with a linear polarizing film, a polarizing beam splitting film, and a quarter-wave plate film.

[0063] The image-side surface R22 of the second lens 212 has a semi-transparent and semi-reflective coating 6.

[0064] refer to Figure 1In the device, a three-in-one film 5, consisting of the linear polarizing film, the polarizing beam splitter (PBS film), and the quarter-wave plate film, is attached to the image-side surface R12 of the first lens 211. The leftmost linear polarizing film blocks S-rays and allows P-rays to pass through. The polarizing beam splitter, located to the right of the linear polarizing film, allows P-rays to pass through while reflecting S-rays. The rightmost quarter-wave plate film of the three-in-one film 5 is a birefringent single-crystal wave plate of a certain thickness, which converts incident circularly polarized light into linearly polarized light. The linear polarizing film, the polarizing beam splitter, and the quarter-wave plate film are sequentially attached to the image-side surface R12 of the first lens 211, and in this embodiment, the thickness of the three-in-one film 5 is 0.255 mm. A semi-transparent, semi-reflective film 6 is deposited on the image-side surface R22 of the second lens 212. The semi-transparent and semi-reflective film 6 is used to allow 50% of the circularly polarized light emitted from the screen to pass through the rightmost quarter-wave plate film of the three-in-one film 5 in this embodiment, becoming S-polarized light. Then, it is reflected by the polarizing beam splitter film in the middle layer of the three-in-one film in this embodiment, passes through the rightmost quarter-wave plate film of the three-in-one film 5 in this embodiment, and is then reflected by the semi-transparent and semi-reflective film 6 on the image side R22 of the second lens 212, passing through the rightmost quarter-wave plate film of the three-in-one film 5 in this embodiment again, becoming P-polarized light. Then, it passes through the polarizing beam splitter film in the middle layer of the three-in-one film 5 in this embodiment, and then passes through the leftmost linear polarizing film of the three-in-one film 5 in this embodiment.

[0065] refer to Figure 1 , Figure 2 and Figure 3 , Figure 1 The structural diagram shown is a schematic diagram of the VR device when the object distance of the liquid lens in this application is -250mm. Figure 2 This is a schematic diagram of the VR device when the object distance of the liquid lens in this application is -500mm. Figure 3 This is a schematic diagram of the VR device when the object distance of the liquid lens in this application is -4000mm. Based on the above, it can be seen that the VR device in this application includes the liquid lens 22, and the curvature of the liquid lens 22 can change according to the change in the object distance of the optical system 1, such as... Figure 1 , Figure 2 and Figure 3 This is a schematic diagram of the structure of the device with the liquid lens 22 described in this embodiment when the object distances are -250mm, -500mm and -4000mm respectively.

[0066] In the device, the first lens 211 and the second lens 212 have the same range of dispersion coefficients;

[0067] The dispersion coefficients of the first lens 211 and the second lens 212 range from 18 to 60.

[0068] In the device, the first lens 211 and the second lens 212 have the same range of dispersion coefficients, specifically 18 to 60. The dispersion coefficient is an important indicator of lens image sharpness, usually expressed by the Abbe number (the reciprocal of the dispersion coefficient). A higher Abbe number indicates less dispersion, and vice versa. It characterizes the separation effect of a material on the light source (spectral lines); the higher the refractive index of the lens material, the greater the dispersion, and thus the lower the Abbe number.

[0069] In the device, the length TTL of the optical system 1 ranges from 32 mm to 40 mm.

[0070] In the device described above, the total length (TTL) of the optical system 1 is the sum of the distance L from the aperture 3 to the first lens 211, the thickness CT1 of the first lens 211, the distance DT1 from the first lens 211 to the second lens 212, the thickness CT2 of the second lens 212, the distance DT2 between the second lens 212 and the liquid lens 22, and the thickness of the liquid lens 22. In the device described in this application, the TTL of the optical system 1 ranges from 32mm to 40mm. In the embodiment of this application, the distance L from the aperture 3 to the first lens 211 is 12mm, the thickness CT1 of the first lens 211 is 2.8mm, the distance DT1 between the first lens 211 and the second lens 212 is 2.908mm, the thickness CT2 of the second lens 212 is 3.214mm, the distance DT2 between the second lens 212 and the liquid lens 22 is 0.1mm, and the TTL of the optical system 1 is 37mm.

[0071] In the device, the effective focal length (EFL) of the optical system 1 ranges from 23 mm to 27 mm.

[0072] In the device, the optical system 1 is a 3P structure, which is a combined lens structure composed of three lenses. The effective focal length (EFL) range is determined by the focal lengths of the first lens 211, the second lens 212, and the liquid lens 22. The effective focal length (EFL) can be calculated based on the focal lengths of the first lens 211, the second lens 212, and the liquid lens 22. In this application, the effective focal length (EFL) range of the optical system 1 is 23mm to 27mm.

[0073] refer to Figure 4 , Figure 4This is a schematic diagram of another VR device according to this application, the device further comprising:

[0074] The display panel 6 is fixed to the image side of the transparent module 2;

[0075] Alternatively, the image side of the lens module 2 may have a mounting structure for detachably placing the display panel 6.

[0076] The device described in this application further includes a transmission surface 4 on the image side of the transmission module 2, and a display panel 6 located on the side of the transmission surface 4 facing away from the lens module 2, or a mounting structure on the image side of the lens module 2 for detachably placing the display panel 6. In the device, the display panel 6 is used for imaging the outgoing light rays from the lens assembly 2.

[0077] Based on Zemax software, the performance of the optical system 1 described in this embodiment is analyzed. The relevant performance diagram and parameter diagram of the optical system 1 are as follows:

[0078] refer to Figure 5 , Figure 5 This is a diagram showing the structural parameters of the optical system in this application;

[0079] refer to Figure 6 , Figure 6 This is a diagram showing the aspherical coefficient distribution of the lens assembly in this application;

[0080] refer to Figure 7 , Figure 7 The MTF plot of the optical system is shown when the object distance of the liquid lens in this application is -4000mm.

[0081] refer to Figure 8 , Figure 8 The MTF diagram of the optical system is shown when the object distance of the liquid lens in this application is -500mm.

[0082] refer to Figure 9 , Figure 9 The MTF diagram of the optical system is shown when the object distance of the liquid lens in this application is -250mm.

[0083] in, Figure 7 , Figure 8 and Figure 9 The MTF analysis charts for the liquid lens 22 at object distances of -4000mm, -500mm, and -250mm are shown. In the MTF analysis charts, the horizontal axis represents space or frequency, and the vertical axis represents the MTF data. The range of the MTF data is 0 to 1. The closer the MTF data is to 1, the better the MTF data is.

[0084] refer to Figure 10 , Figure 10 This is a relative illumination diagram of the optical system in this application. The horizontal axis of the relative illumination diagram of the optical system is the image height, and the vertical axis is the relative illumination data.

[0085] refer to Figure 11 , Figure 11 This is a schematic diagram of the field curvature of the optical system in this application. The horizontal axis of the schematic diagram of the field curvature of the optical system is the field curvature, and its vertical axis is the field of view angle.

[0086] refer to Figure 12 , Figure 12 This is a distortion diagram of the optical system in this application. The horizontal axis of the distortion diagram represents the distortion data, and the vertical axis represents the field of view.

[0087] Based on the above, this application proposes a VR device, which includes a liquid lens 22, and the liquid lens 22 can change its curvature based on electric field control; the curvature of the liquid lens 22 is related to the object distance of the optical system 1; the object distance is the distance between the aperture 3 and the formed virtual image. The liquid lens 22 changes its curvature based on electric field control, so that the curvature of the liquid lens 22 changes according to the object distance of the optical system 1, thereby achieving a zoom effect. The device uses an electrically zoomable liquid lens to achieve focal length adjustment, eliminating the need for a motor, reducing the device's volume in the optical axis direction, and providing fast zoom speed with no motor noise during the zoom process.

[0088] The various embodiments in this specification are described in a progressive, parallel, or combined manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0089] It should be noted that, in the description of this application, the drawings and embodiments are illustrative rather than restrictive. The same reference numerals throughout the embodiments identify the same structures. Additionally, for ease of understanding and description, the thicknesses of some layers, films, panels, regions, etc., may be exaggerated in the drawings. It is also understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, the element may be directly on the other element or there may be intermediate elements. Furthermore, "on" means positioning an element on or below another element, but does not inherently mean positioning it above another element according to the direction of gravity.

[0090] The terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component positioned centrally in the middle.

[0091] It should also be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes the aforementioned element.

[0092] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A VR device, characterized in that, The device includes: An optical system, comprising a lens module and an aperture; the length of the optical system ranges from 32mm to 40mm, and the effective focal length ranges from 23mm to 27mm; The lens module includes a fixed-focus lens assembly and an electrically zoomable liquid lens arranged coaxially. The side of the fixed-focus lens assembly facing away from the liquid lens is the object side, and the side of the liquid lens facing away from the fixed-focus lens assembly is the image side. The fixed-focus lens assembly consists of a first lens and a second lens. The object side of the second lens is convex, and the image side is concave. The radius of curvature of the object side of the first lens is +101.926 mm, and the equivalent focal length of the first lens is 152.15 mm. The radius of curvature of the object side of the second lens is +754.302 mm, and the radius of curvature of the image side is -93.787 mm. The equivalent focal length of the second lens is 216.4 mm. The aperture is located on the side of the fixed-focus lens assembly away from the liquid lens and is coaxial with the lens module; The liquid lens contains a curvature-variable liquid lens curvature film, which can change its curvature based on an electric field. The curvature of the liquid lens curvature film is related to the object distance of the optical system. The object distance is the distance between the aperture and the formed virtual image. In the direction from the object side to the image side, when the liquid lens curvature film is convex, its radius of curvature is greater than +88; when the liquid lens curvature film is concave, its radius of curvature is less than -88.

2. The device according to claim 1, characterized in that, The first lens and the second lens have the same refractive index range.

3. The device according to claim 2, characterized in that, The refractive index range of the first lens and the second lens is 1.49 to 1.

8.

4. The device according to claim 2, characterized in that, Both the first lens and the second lens are plastic lenses.

5. The device according to claim 2, characterized in that, The object-side surface of the first lens is convex, and the image-side surface is planar.

6. The device according to claim 5, characterized in that, The image side of the first lens is covered with a linear polarizing film, a polarizing beam splitter film, and a quarter-wave plate film; The image-side surface of the second lens has a semi-transparent and semi-reflective coating.

7. The device according to claim 2, characterized in that, The first lens and the second lens have the same range of dispersion coefficients; The dispersion coefficients of the first lens and the second lens range from 18 to 60.

8. The device according to claim 1, characterized in that, The device also includes: A display panel fixed to the image side of the lens module; Alternatively, the image side of the lens module may have a mounting structure for detachably placing the display panel.

Images