Zoom optical device and near-eye display system

Abstract

The invention provides a zoom optical device and a near-eye display system. In one aspect, a zoom optical device includes: a flexible optical element having a deformable optical surface; a driving source configured to provide a single-dimensional control variable; and a physical coding modulation unit coupled between the driving source and the flexible optical element and having a preset non-uniform physical property distribution corresponding to geometric information of a target optical surface type of the optical surface, the physical coding modulation unit being configured to receive a control variable and to modulate the target optical surface type of the optical surface according to the non-uniform physical property distribution. The control variable is converted into a non-uniformly distributed acting load applied to the flexible optical element to deform the optical surface into a target optical surface type. Therefore, the control complexity, the size and the power consumption of the system are reduced, and the reliability of the system is improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of display, in particular, to a zoom optical device and a near-eye display system. BACKGROUND

[0002] With the rapid development of micro-imaging systems, portable optical instruments, and head-mounted display devices, modern optical systems are evolving towards thinness, integration, and low power consumption. In these application scenarios, dynamic optical elements that can achieve fast, continuous, and high-precision zooming are key components to improve system performance.

[0003] In particular, in augmented reality (AR), virtual reality (VR), mixed reality (MR), and other near-eye display systems, dynamic zooming function is crucial to improve user experience.

[0004] On the one hand, in order to alleviate the visual vergence-accommodation conflict (VAC) caused by the inconsistency between the vergence distance of the two eyes and the accommodation distance of the lens, the near-eye display system needs to adjust the virtual image distance in real time according to the depth information of the virtual image; on the other hand, in order to adapt to the vision conditions of different user groups, the near-eye display system also needs to provide diopter adjustment function.

[0005] However, the near-eye display system has extremely stringent limitations on control complexity, volume, power consumption, and reliability. SUMMARY

[0006] This section provides a general summary of the present disclosure, rather than a comprehensive disclosure of the full scope or all features of the present disclosure.

[0007] According to an aspect of the present disclosure, a zoom optical device is provided, including a flexible optical element, a driving source, and a physical coding modulation unit. The flexible optical element has a deformable optical surface. The driving source provides a single-dimensional control variable. The physical coding modulation unit is coupled between the driving source and the flexible optical element, and has a preset non-uniform physical property distribution corresponding to the geometric information of a target optical surface profile of the optical surface. The physical coding modulation unit receives the control variable and converts the control variable into a non-uniformly distributed action load applied to the flexible optical element according to the non-uniform physical property distribution, so as to deform the optical surface into the target optical surface profile.

[0008] According to another aspect of the present disclosure, there is provided a zoom optical device, comprising a flexible mirror, a rigid encoder plate, a hydrostatic coupling layer, and a linear actuator. The flexible mirror has a deformable reflecting surface. The surface of the rigid encoder plate has a geometric profile height distribution defined based on an Alvarez surface equation. The hydrostatic coupling layer is located between the rigid encoder plate and the flexible mirror, and has a flexible bottom surface that conforms to the surface of the rigid encoder plate. The linear actuator is connected to the rigid encoder plate, and drives the rigid encoder plate to move relative to the hydrostatic coupling layer, so that the flexible bottom surface deforms according to the geometric profile height distribution, which is converted by an incompressible fluid or gel in the hydrostatic coupling layer into a differential pressure field applied to the flexible mirror, to change the optical power of the flexible mirror.

[0009] According to still another aspect of the present disclosure, there is provided a near-eye display system, comprising an image source and the above-mentioned zoom optical device. The image source generates image light rays. The zoom optical device is disposed in the optical path of the image light rays, for adjusting the virtual image distance of the image light rays. BRIEF DESCRIPTION OF DRAWINGS

[0010] The features and advantages of embodiments of the present disclosure will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings. The drawings are not drawn to scale, and some features can be exaggerated to illustrate particular features. In the drawings:

[0011] Figure 1 A schematic diagram of an optical path architecture of a near-eye display system according to an embodiment of the present disclosure.

[0012] Figure 2 A schematic diagram of a zoom optical device according to an embodiment of the present disclosure.

[0013] Figure 3 A schematic diagram of a zoom optical device according to another embodiment of the present disclosure. Figure 2 A schematic diagram of another view of the zoom optical device shown.

[0014] Figure 4 A schematic diagram of a zoom optical device according to another embodiment of the present disclosure. Figure 2 A schematic diagram of a zoom optical device in a first working state.

[0015] Figure 5 A schematic diagram of a zoom optical device in a second working state. Figure 2 A schematic diagram of a zoom optical device in a second working state.

[0016] Figure 6 A schematic diagram of a zoom optical device according to another embodiment of the present disclosure. Figure 2 A graph showing the relationship between the deformation profile of the flexible optical element and the driving displacement of the zoom optical device shown.

[0017] Figure 7 A schematic diagram of a zoom optical device according to another embodiment of the present disclosure.

[0018] Figure 8 Schematic diagram of a zoom optical device according to yet another embodiment of the present disclosure.

[0019] Figure 9 Schematic diagram of a zoom optical device according to still another embodiment of the present disclosure.

[0020] Figure 10 Schematic diagram of a zoom optical device according to yet another embodiment of the present disclosure.

[0021] In the drawings, the same or corresponding technical features or components are denoted by the same or corresponding reference signs. DETAILED DESCRIPTION

[0022] The present disclosure will be described in detail below with reference to the drawings, by means of exemplary embodiments. It should be noted that the following detailed description of the present disclosure is merely for illustrative purposes, and is by no means a limitation on the present disclosure.

[0023] It should be noted that, for the sake of clarity, not all features of a specific embodiment are described and shown in the specification and drawings, and in order to avoid obscuring the technical solutions of the present disclosure that are the focus of the present disclosure, only the device structures closely related to the technical solutions of the present disclosure are described and shown in the specification and drawings, and other details that are not closely related to the technical content of the present disclosure and are known to those skilled in the art are omitted.

[0024] With the rapid development of AR, VR, MR and other technologies, near-eye display systems are gradually moving from professional fields to the mass consumer market. In these systems, users observe virtual images generated by miniature image sources through optical combiners or eyepieces. However, in related near-eye display technologies, VAC is a long-standing and urgent problem. In natural vision, the binocular convergence point (verge) of the human eye and the focusing plane of the lens naturally coincide in physical space. However, in the current stereoscopic display system, although the two eyes converge on virtual objects at different depths, the lens is forced to always focus on a fixed screen or waveguide plane. This decoupling of physiological mechanisms can cause visual fatigue, depth perception errors, and even severe dizziness and nausea in users, which hinders the long-term use experience of near-eye display devices.

[0025] To address this, various variable-focus optical solutions have been proposed in the industry, aiming to dynamically adjust the virtual image distance of the virtual image to match the convergence depth of the human eye. Among related technologies, a variable-focus solution based on flexible deformable mirror technology using micro-actuator arrays has been proposed. This technology typically involves arranging an array of dozens or even hundreds of independent micro-actuators (such as piezoelectric ceramics) on the back of a flexible mirror. By applying different voltages to each actuator to produce different amounts of stretching, the flexible mirror surface can be pushed at multiple points on a micrometer scale, thereby fitting the desired optical profile.

[0026] However, this multi-point active control scheme relying on electronic intelligence faces several insurmountable obstacles when applied to consumer-grade near-eye display devices. Firstly, the control system is complex and bulky. To obtain a smooth and precise optical surface, a high-performance processor is needed for real-time, complex calculations, along with expensive and large multi-channel high-voltage drive circuits to control each actuator—a feat difficult to achieve in thin and light AR or VR glasses. Secondly, the processor and multi-channel drive system generate significant power consumption and heat, affecting the device's battery life and wearing comfort. Furthermore, each actuator exhibits individual differences such as hysteresis, nonlinearity, and drift, requiring complex feedback loops for continuous calibration. The large number of electronic and mechanical components also means more potential points of failure, resulting in lower long-term system reliability. Finally, the cost of the micro-actuator array and corresponding control system is high, exceeding the affordability of consumer-grade products.

[0027] To address the aforementioned problems, according to embodiments of this disclosure, a zoom optical device and a near-eye display system are provided.

[0028] Before delving into the specific structure and working mechanism of the zoom optical device disclosed herein, it is necessary to first describe the application environment and system architecture of the zoom optical device in order to understand its key role in the optical system.

[0029] The near-eye display system 10 provided in this disclosure can be configured as an AR head-mounted display, a VR head-mounted display, or a MR head-mounted display. In a wider range of applications, the optical architecture used in this near-eye display system can also be applied to fields with stringent limitations on control complexity, size, power consumption, and reliability, such as miniature imaging systems, portable medical optical instruments, and adaptive optics imaging systems.

[0030] Reference Figure 1 The schematic diagram of the optical path architecture shown indicates that the near-eye display system 10 includes a zoom optical device 100 and an image source 200.

[0031] Image source 200 is configured to generate image rays S1 carrying virtual information. For example, image source 200 may employ display technologies such as Liquid Crystal on Silicon (LCoS), Digital Light Processing (DLP), Micro Light-Emitting Diode (Micro-LED), or Micro Organic Light-Emitting Diode (Micro-OLED).

[0032] The zoom optical device 100 is placed in the optical path of the image ray S1 and is used to adjust the virtual image distance of the image ray S1. For example... Figure 1 Taking the optical path architecture of AR glasses as an example, the image light S1, after zoom adjustment, then enters the beam combiner 300. The beam combiner 300 is used to guide the image light S1 to the human eye 20, while allowing the real scene light S2 from the external environment to pass through, thereby achieving a visual effect of virtual-real fusion. It is conceivable that the beam combiner 300 can be a semi-transparent mirror, a freeform prism, etc.

[0033] The VAC problem can be solved by dynamically adjusting the virtual image distance. Specifically, when the near-eye display system needs to render a virtual object located nearby, in addition to adjusting the binocular parallax, the zoom optics 100 will correspondingly increase the optical power, making the light present a larger divergence angle. This induces the human eye's lens to adjust naturally, keeping the convergence depth consistent with the accommodation depth, thus eliminating dizziness from a physiological mechanism perspective. Furthermore, the zoom optics 100 can also be used to compensate for the user's own refractive errors, such as myopia or hyperopia, allowing the user to obtain a clear visual experience without wearing additional corrective glasses.

[0034] Below, refer to Figures 2 to 6 The zoom optical device 100 according to embodiments of the present disclosure will be described in detail.

[0035] like Figure 2 and Figure 3 As shown, the zoom optical device 100 includes a flexible optical element 120 and a drive source 140 (see...). Figure 3 ) and physical coding modulation unit 160.

[0036] The flexible optical element 120 has a deformable optical surface 122. For example, the flexible optical element 120 can be a flexible mirror with a high-reflectivity coating on its surface, or a flexible lens with transmission capability. The substrate of the flexible optical element 120 is usually selected from polymer materials or ultra-thin glass with high elastic modulus and fatigue resistance, so as to maintain excellent optical surface quality under repeated deformation.

[0037] Unlike traditional rigid optical elements, the optical power of the flexible optical element 120 is not fixed, but dynamically adjusted with the physical changes of its surface profile.

[0038] The driving source 140 is introduced to drive the flexible optical element 120 to deform. The driving source 140 is configured to provide a single-dimensional control variable. Here, the "single dimension" means that the control signal only needs to change in one degree of freedom, for example, the linear displacement amount, the rotation angle, the fluid volume change amount, or the temperature change amount. Exemplarily, for the linear displacement amount, the driving source 140 can be a micro linear motor, such as a voice coil motor, a piezoelectric motor, etc.

[0039] The physical coding modulation unit 160 is coupled between the driving source 140 and the flexible optical element 120, and has a preset non-uniform physical property distribution. This "non-uniform physical property distribution" is not randomly generated, but has a strict corresponding relationship with the geometric information of the target optical surface profile of the optical surface 122 of the flexible optical element 120.

[0040] In other words, the mathematical equation of the curved surface (such as the parabolic equation) required to achieve ideal optical imaging is "coded" and fixed in the physical properties such as the geometric shape, material properties, etc. of the physical coding modulation unit 160 in advance. In the working process, the physical coding modulation unit 160 receives the single-dimensional control variable (such as displacement d) from the driving source 140, and according to its own preset non-uniform physical property distribution, converts this simple input into a non-uniformly distributed action load applied to the back surface 124 of the flexible optical element 120.

[0041] This non-uniformly distributed action load is used to change the optical surface profile. Because the thrust or pressure received by each point of the flexible optical element 120 is different, the optical surface 122 will produce non-uniform deformation, and finally present the expected target optical surface profile.

[0042] In the above technical solution, the target optical surface profile is realized by the input of a single-dimensional control variable, which fundamentally simplifies the control system. In the related art solution based on a micro-actuator array, in order to fit a complex optical curved surface, dozens or even hundreds of actuators need to be controlled at the same time, and each actuator needs an independent voltage driving channel, which results in a considerable hardware volume and power consumption. In the present embodiment, only one control variable output by one driving source is needed to complete the complex zooming task, thereby reducing the control dimension from complex N dimensions to simple one dimension, greatly reducing the control complexity and reducing the volume.

[0043] In addition, the physical coding modulation unit 160 accomplishes the operation process from "simple input" to "complex output" by using physical structure, thereby greatly reducing the dependence of the system on electronic computing power, without the need for high-performance processors for real-time fitting calculation, and without the need for complex closed-loop feedback circuits, thereby greatly reducing power consumption.

[0044] In addition, the physical property distribution is once manufactured, for example, solidified on the rigid component by precision machining, and its characteristics are uniquely determined by physical laws, without the problems of actuator hysteresis, electronic component drift, aging, or software crash, greatly improving the reliability of the system.

[0045] In some embodiments, as shown in Figure 2 and Figure 3 The physical coding modulation unit 160 includes a rigid base body 162 and a hydrostatic coupling layer 164.

[0046] The surface 1620 of the rigid base body 162 is not a plane, but has a specific geometric profile height distribution, which constitutes the aforementioned non-uniform physical property distribution. The rigid base body 162 may, for example, be in the form of a rigid coding plate. The rigid base body 162 is usually made of a high-rigidity material, so that its surface profile remains stable in long-term use.

[0047] The hydrostatic coupling layer 164 is located between the rigid base body 162 and the flexible optical element 120, and the inside of the hydrostatic coupling layer 164 is filled with a medium.

[0048] As shown in Figure 4 and Figure 5 Under this structure, the driving source 140 is configured to drive the rigid base body 162 to produce a tangential displacement relative to the hydrostatic coupling layer 164, which is the aforementioned control variable. As the rigid base body 162 slides in the X-axis direction in the tangential direction (for example Figure 4 and Figure 5 Due to the undulating geometric profile of its surface 1620, the height variation at different positions changes the boundary conditions of the bottom 1644 of the hydrostatic coupling layer 164. The hydrostatic coupling layer 164 uses the volume transfer characteristics of the internal medium to convert the geometric profile height distribution of the surface 1620 of the rigid base body 162 in combination with the tangential displacement into a normal pressure distribution applied to the back surface 124 of the flexible optical element 120.

[0049] In order to achieve high-quality imaging effects, this normal pressure distribution is not arbitrarily set, but needs to follow strict optical physical laws.

[0050] In some embodiments, as shown in Figure 2As shown, the surface 1620 of the rigid substrate 162 is configured as a free-form surface. The geometric profile height distribution of the free-form surface is not arbitrarily set, but is inversely solved and designed based on the principle of differential geometry, aiming to establish a certain displacement-to-surface conversion relationship.

[0051] Specifically, the surface 1620 of the rigid substrate 162 is configured such that the rate of change of the geometric profile height distribution along the tangential displacement direction is in proportional relationship with the sag of the target optical surface at the corresponding position.

[0052] It can be understood that the rate of change of the geometric profile height distribution along the tangential displacement direction corresponds to the derivative of the surface function of the rigid substrate 162 in this direction in the mathematical and physical sense. The target optical surface refers to the ideal optical curved surface shape that the flexible optical element 120 needs to present during zooming. That is, the operation logic of the physical coding modulation unit 160 physically realizes the derivation operation of the surface profile of the rigid substrate 162 by using the differential transmission effect of the hydrostatic pressure coupling layer 164.

[0053] Under actual working conditions, when the driving source 140 drives the rigid substrate 162 to produce a small displacement d along the tangential direction (for example, the X-axis direction), the boundary conditions of the bottom 1644 of the hydrostatic pressure coupling layer 164 change accordingly. The small height change of the bottom boundary of the hydrostatic pressure coupling layer 164 will be transmitted to the top 1642 by the medium, thereby forcing the flexible optical element 120 to produce a normal displacement, that is, Figure 4 and Figure 5 the Z-axis direction displacement.

[0054] According to the Taylor series expansion principle, under the condition of small displacement approximation, the normal displacement amount (i.e., the deformation amount of the flexible optical element 120) Δz is approximately equal to the product of the displacement amount d and the slope (or partial derivative) of the surface 1620 of the rigid substrate 162 in the tangential direction.

[0055] Referring to Figure 6 , which respectively shows the deformation amount Δz of the flexible optical element 120 in the Z-axis direction under three conditions of movement distances d1, d2 and d3 (d1

[0056] Therefore, by simply changing the size of the tangential displacement, the power of the target optical surface can be linearly adjusted, thereby ensuring the stability of the optical performance during continuous zooming.

[0057] In the field of optical imaging, in order to eliminate spherical aberration and obtain a clear image, the ideal optical surface profile generally needs to satisfy the characteristics of a quadratic parabolic function.

[0058] In this regard, in some embodiments, the geometric profile height distribution is configured to satisfy the characteristics of a cubic polynomial function. Specifically, by utilizing the derivative characteristics of the Alvarez surface that satisfies the characteristics of a cubic polynomial function, a quadratic parabolic deformation can be generated by a simple linear movement.

[0059] Mathematically, if the surface height function of the rigid substrate 162 is defined as z(x, y) and satisfies the characteristics of a cubic polynomial, it is, for example, as follows: z(x, y) = C(x 3 / 3+xy 2 ) where C is a predetermined constant coefficient, x is the coordinate along the tangential direction, and y is the transverse coordinate perpendicular to the tangential direction.

[0060] When the rigid substrate 162 moves a small distance d along the X-axis direction, the fluid static pressure coupling layer 164 actually performs a physical difference operation on the Alvarez surface. According to the Taylor expansion principle, the height change Δz caused by this movement is approximately proportional to d multiplied by the partial derivative of z with respect to x, that is: Δz≈d×( z / x)。

[0061] Taking the partial derivative of the above cubic function, the following equation can be obtained: z / x=C×(x 2 +y 2 )。

[0062] It can be seen that the result is a perfect rotational symmetric parabolic equation.

[0063] This means that by processing the rigid substrate 162 to have a surface 1620 that is a specific Alvarez cubic surface and utilizing the fluid layer for difference transmission, the present disclosure realizes the conversion from one-dimensional linear movement to two-dimensional ideal parabolic surface profile. The deformation of the flexible optical element 120 under the normal pressure distribution strictly follows this quadratic parabolic function characteristic, thereby ensuring the optical performance during zooming.

[0064] As the driving source 140 drives the rigid substrate 162 to move different distances d, the opening amplitude of the parabolic curve changes linearly, thereby realizing continuous and accurate focal power adjustment. This mechanical coding method based on mathematical principles not only eliminates the surface profile error in the multi-actuator scheme of the related art, but also greatly improves the response speed and stability of the system.

[0065] In some embodiments, as shown in FIG. 1, the physical encoding modulation unit 160 further comprises a linear guide 166. Figure 3

[0066] The linear guide 166 is arranged on the side of the rigid base 162, for example, which is implemented as a rigid encoding plate, to support the rigid base 162 and guide the linear motion of the rigid base 162 thereon.

[0067] The linear guide 166 can restrict the rigid base 162 from moving in other degrees of freedom, to improve the stability and accuracy of the motion of the rigid base 162, and thus improve the accuracy of the obtained target optical surface type.

[0068] The hydrostatic coupling layer 164 is further described below.

[0069] As shown in FIG. 1, the hydrostatic coupling layer 164 is a sealed cavity structure. The hydrostatic coupling layer 164 comprises a top portion 1642 and a bottom portion 1644. Figures 2 to 5

[0070] The top portion 1642 is directly coupled with the back surface 124 of the flexible optical element 120, or connected by adhesion or the like. Thus, any deformation of the top portion 1642 will be directly transmitted to the flexible optical element 120, changing its curvature.

[0071] The bottom portion 1644 is designed to be flexible, and is configured to abut the surface 1620 of the rigid base 162. The bottom portion 1644 can be made of a flexible film material with high compliance, for example, which enables the bottom portion 1644 to closely fit on the surface 1620 of the rigid base 162. When the rigid base 162 moves relative to the bottom portion 1644 under the driving of the driving source 140, the bottom portion 1644 will deform following the geometric profile height distribution due to the height variation of the surface 1620 with position.

[0072] In the present embodiment, the position of the flexible optical element 120 is fixed macroscopically, only microscopically curved in surface type, and the hydrostatic coupling layer 164 is also fixed. Only the rigid base 162 is moving tangentially. When the rigid base 162 moves, it squeezes or releases the space of the bottom portion 1644 of the hydrostatic coupling layer 164, causing the deformation of the bottom portion 1644. This deformation is transmitted to the top portion 1642 through the medium. In other words, the hydrostatic coupling layer 164 converts the tangential displacement (X-axis motion) of the rigid base 162 into a vertical volumetric displacement (Z-axis motion), and then pushes the flexible optical element 120 to deform.

[0073] ​​It is envisaged that the medium filled in the hydrostatic coupling layer 164 is an incompressible fluid or gel, so that the volume change caused by the movement of the rigid substrate 162 is completely transmitted to the flexible optical element 120, to ensure the accuracy of the transmission of the above-mentioned volume displacement.

[0074] In some embodiments, with reference to Figure 7 , the zoom optical device 100 further comprises a pre-tightening element 180.

[0075] The pre-tightening element 180 can be a spring, an elastic pressing plate or the like structure. The pre-tightening element 180 is configured to apply a pressure to the hydrostatic coupling layer 164 which is perpendicular to the surface 1620 of the rigid substrate 162 (i.e. the pressure in the Z-axis direction), so that the hydrostatic coupling layer 164 is kept in close contact with the rigid substrate 162.

[0076] In this way, the hydrostatic coupling layer 164 is in a state of being always under force, no matter whether the rigid substrate 162 moves to the left or to the right, the flexible bottom 1644 of the hydrostatic coupling layer 164 can respond immediately, thereby improving the dynamic response characteristics and the repeatability of positioning accuracy. In addition, the pre-tightening force also helps to improve the sealing of the hydrostatic coupling layer 164, preventing the medium from leaking.

[0077] In the chamber of the hydrostatic coupling layer 164, if the fluid can flow freely in all directions, when the rigid substrate 162 at a certain point is elevated to press the fluid, the fluid may flow to the surrounding area with lower pressure instead of pushing the flexible optical element 120 vertically upward, which will cause the final optical surface to become flat and unable to present the desired parabolic characteristics.

[0078] In this regard, it is envisaged that the interior of the hydrostatic coupling layer 164 can be provided with a microstructure array. The microstructures in the microstructure array can be, for example, micro-honeycomb grids, columnar arrays, etc. These microstructures are open or flexible in the Z-axis direction, allowing pressure to be transmitted vertically, but form a physical barrier in the X-axis and Y-axis directions, which can inhibit the lateral flow of the fluid in the hydrostatic coupling layer 164.

[0079] Alternatively, it is envisaged that the interior of the hydrostatic coupling layer 164 is filled with a gel with a high shear modulus. A high shear modulus means that the material is not easy to deform when subjected to shear force (lateral force), but can still transmit pressure when subjected to normal pressure. This material property itself can effectively limit the lateral flow, so that the deformation points of the bottom 1644 are transmitted point by point to the top 1642.

[0080] In some embodiments, with reference to Figure 8 , the physical coding modulation unit 160 comprises a rotating cam 262 and a link array 264.

[0081] The rotary cam 262 has a non-circular radial profile. Here, "non-circular" means that the radius of the rotary cam 262 varies with the angle of rotation.

[0082] One end of the link 2640 in the link array 264 is connected to the rotary cam 262 as a follower to read the radius of the rotary cam 262, and the other end is connected to the actuation point on the back surface 124 of the flexible optical element 120. When a drive source 140, for example a motor, drives the rotary cam 262 connected to it to rotate, different radius values ​​at different angles are pushed and pulled to different positions on the back surface 124 of the flexible optical element 120 through the link 2640.

[0083] In this case, the non-uniform physical property distribution is the rate of change of the radial profile and the lever ratio distribution of the linkage array. The drive source 140 is configured to drive the rotary cam 262 to rotate by a certain angle as a control variable. The radial profile of the rotary cam 262 converts this rotation angle into the displacement distribution of the linkage array 264, and then into a non-uniform force applied to multiple discrete points of the flexible optical element 120.

[0084] Furthermore, in some implementations, reference is made to Figure 9 The physical coding modulation unit 160 includes a microfluidic cavity array 362. The microfluidic cavity array 362 is arranged on the back side 124 of the flexible optical element 120.

[0085] As an example, the physical coding modulation unit 160 also includes a rigid base 364. The microfluidic chamber array 362 is placed on the rigid base 364 for support.

[0086] At this point, the non-uniform physical property distribution is the geometric size distribution (such as the width, length, and depth of the fluid channels in each microfluidic chamber 3620 of the microfluidic chamber array 362).

[0087] In this architecture, the drive source 140 includes a fluid pump. This fluid pump is configured to inject fluid into or extract fluid from the microfluidic chamber 3620 (e.g., ...). Figure 9 (As shown by the double-headed arrow in the diagram). The control variable here is the total volume or total pressure output by the fluid pump.

[0088] When the fluid pump operates, fluid with a specific pressure or volume enters the microfluidic chamber array 362. Since the geometry of the fluid channels in each microfluidic chamber 3620 of the microfluidic chamber array 362 is pre-designed, different positions of the fluid channels exert different levels of resistance on the fluid. According to fluid mechanics principles, the fluid will generate a specific pressure drop distribution as it passes through these channel arrays. Therefore, a simple, uniform inlet pressure, after being modulated by the microfluidic chamber array 362, is converted into a non-uniform fluid pressure distribution applied to various points on the back surface 124 of the flexible optical element 120.

[0089] Furthermore, in some implementations, reference is made to Figure 10 (The working principle of the zoom optical device 100 of this embodiment is shown in an exploded view on the left, and the assembled zoom optical device 100 is shown on the right.) The physical coding modulation unit 160 includes a composite material layer 462. The composite material layer 462 is bonded to the back surface 124 of the flexible optical element 120.

[0090] At this point, the non-uniform physical property distribution is a patterned geometric distribution of different materials in the composite layer 462. Specifically, the composite layer 462 is typically composed of two or more materials with different coefficients of thermal expansion (e.g., a bimetallic layer). Figure 10 An exemplary illustration shows that the composite material layer 462 includes a first material layer 4622 and a second material layer 4624 with different coefficients of thermal expansion. During the manufacturing stage, for example by photolithography or mask deposition techniques, a specific geometric pattern is fabricated into the composite material layer 462. This pattern is the encoded information.

[0091] The corresponding driving source 140 includes a heat source (e.g., a transparent conductive heating film). The controlled variable is the change in temperature output from the heat source. When the heat source uniformly heats the entire flexible optical element 120 ( Figure 10 (The image shows a curved line with an arrow indicating the heating process). Because the material composition varies at different locations in the composite layer 462 (e.g., some areas are materials with a high coefficient of thermal expansion, while others are materials with a low coefficient of thermal expansion), their responses to temperature (expansion or contraction) are different. This differential thermal expansion generates internal stress within the material, which in turn forces the flexible optical element 120 to bend and deform.

[0092] Therefore, by designing the pattern distribution of composite materials, simple global temperature changes can be accurately converted into complex optical surface deformations.

[0093] The physical coding modulation unit 160 described above can generate a specific target optical profile. In some embodiments, the change in the target optical profile is configured to compensate for VAC or correct the user's refractive errors (such as myopia, hyperopia, astigmatism).

[0094] This means that the zoom optical device of this application can be deeply customized for the visual characteristics of the human eye. For example, the Alvarez surface parameters on the rigid encoder plate can be optimized according to the average accommodation range of the human eye (e.g., 0 to 3 diopters), so that the full stroke movement of the rigid encoder plate on the rigid guide rail exactly covers this diopters range, thereby solving the VAC problem while maximizing the accommodation accuracy.

[0095] In this disclosure, the terms "first," "second," "third," etc., are used merely for descriptive purposes and should not be considered restrictive. Furthermore, although this disclosure has been described with reference to exemplary embodiments, it should be understood that this disclosure is not limited to the specific embodiments described and shown herein. Various changes to the exemplary embodiments can be made by those skilled in the art without departing from the scope defined by the claims of this disclosure.

[0096] The features mentioned and / or shown in the foregoing description of exemplary embodiments of this disclosure may be combined in the same or similar manner with one or more other embodiments, combined with features in other embodiments, or substituted for corresponding features in other embodiments. Such combinations or substitutions should also be considered as including within the scope of protection of this disclosure.

Claims

1. A zoom optical device, characterized in that, include: Flexible optical elements with deformable optical surfaces; The driver source is configured to provide a single-dimensional control variable. as well as A physical coding modulation unit is coupled between the driving source and the flexible optical element, and has a preset non-uniform physical property distribution, which corresponds to the geometric information of the target optical surface shape of the optical surface. The physical coding modulation unit is configured to receive the control variable and, based on the non-uniform physical property distribution, convert the control variable into a non-uniformly distributed load applied to the flexible optical element, so as to deform the optical surface into the target optical surface shape.

2. The zoom optical device according to claim 1, characterized in that, The physical coding modulation unit includes: A rigid substrate, wherein the non-uniform physical property distribution is the geometric contour height distribution of the surface of the rigid substrate; and A hydrostatic coupling layer, filled with a medium, is located between the rigid substrate and the flexible optical element. The driving source is configured to drive the rigid substrate to generate a tangential displacement relative to the hydrostatic coupling layer as the control variable, and the geometric profile height distribution converts the tangential displacement into a normal pressure distribution applied to the flexible optical element through the hydrostatic coupling layer.

3. The zoom optical device according to claim 2, characterized in that, The surface of the rigid substrate is constructed as a freeform surface, such that the rate of change of the geometric profile height distribution along the tangential displacement direction is proportional to the sagitta of the target optical surface at the corresponding position.

4. The zoom optical device according to claim 3, characterized in that, The geometric profile height distribution satisfies the characteristics of a cubic polynomial function, and the deformation of the flexible optical element under the normal pressure distribution satisfies the characteristics of a quadratic parabolic function.

5. The zoom optical device according to claim 2, characterized in that, The rigid substrate is a rigid encoding plate, and the physical encoding modulation unit further includes a linear guide rail, which supports the rigid encoding plate and guides the rigid encoding plate to move linearly on the linear guide rail.

6. The zoom optical device according to claim 2, characterized in that, The hydrostatic coupling layer includes: Top, coupled to the flexible optical element; and The bottom is flexible, abutting against the surface of the rigid substrate, and is configured to deform following the height distribution of the geometric contour. When the rigid substrate moves relative to the bottom, the deformation of the bottom is transmitted to the top through the medium.

7. The zoom optical device according to claim 6, characterized in that, The bottom is a wear-resistant, highly compliant film.

8. The zoom optical device according to claim 2, characterized in that, The medium is an incompressible fluid or gel.

9. The zoom optical device according to claim 2, characterized in that, It also includes a preload element configured to apply pressure perpendicular to the surface of the rigid substrate to the hydrostatic coupling layer so that the hydrostatic coupling layer remains in contact with the rigid substrate.

10. The zoom optical device according to claim 2, characterized in that, The fluid static coupling layer may have an array of microstructures inside that can suppress the lateral flow of the fluid, or the fluid static coupling layer may be filled with a gel with a high shear modulus.

11. The zoom optical device according to claim 1, characterized in that, The physical coding modulation unit includes: A rotary cam with a non-circular radial profile; and A linkage array, wherein one end of each linkage abuts against the rotating cam and the other end is connected to an actuation point on the back of the flexible optical element, and the non-uniform physical property distribution comprises the rate of change of the radial profile and the lever ratio distribution of the linkage array. The drive source is configured to drive the rotary cam to rotate by a certain angle as the control variable, and the radial profile converts the rotation angle into a non-uniform force applied to multiple discrete points of the flexible optical element through the linkage array.

12. The zoom optical device according to claim 1, characterized in that, The physical coding modulation unit includes a microfluidic cavity array, which is arranged on the back side of the flexible optical element. The non-uniform physical property distribution refers to the geometric size distribution of the fluid channels in the microfluidic cavity array. The driving source includes a fluid pump, and the control variable is the volume or pressure of fluid injected into or extracted from the microfluidic chamber by the fluid pump. The geometric distribution converts the volume or pressure into a non-uniform fluid pressure distribution applied to the back of the flexible optical element.

13. The zoom optical device according to claim 1, characterized in that, The physical coding modulation unit includes a composite material layer bonded to the back side of the flexible optical element. The non-uniform physical property distribution is a patterned geometric distribution of materials with different coefficients of thermal expansion in the composite material layer. The driving source includes a heat source, the control variable is the temperature change output by the heat source, and the patterned geometric distribution converts the temperature change into a non-uniform load applied to the back of the flexible optical element.

14. A zoom optical device, comprising: Flexible mirrors have deformable reflective surfaces; A rigid encoder plate, the surface of which has a geometric profile height distribution defined based on the Alvarez surface equation; A hydrostatic coupling layer is located between the rigid coding plate and the flexible reflector. The hydrostatic coupling layer has a flexible bottom surface that is attached to the surface of the rigid coding plate. as well as A linear actuator, connected to the rigid encoder plate, drives the rigid encoder plate to move relative to the hydrostatic coupling layer, causing the flexible bottom surface to deform according to the geometric profile height distribution. The deformation is converted into a differential pressure field applied to the flexible mirror by an incompressible fluid or gel within the hydrostatic coupling layer, thereby changing the optical power of the flexible mirror.

15. A near-eye display system, characterized in that, include: The image source is configured to generate image rays; as well as According to any one of claims 1 to 14, the zoom optical device is disposed in the optical path of the image light and is used to adjust the virtual image distance of the image light.

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