Polarization-insensitive tunable lens of crossed doublet and its lamination packaging method

Abstract

The application discloses a polarization-insensitive adjustable-focus lens of a quadrature double-layer lens and a lamination packaging method thereof, and relates to the field of adjustable-focus lenses. The lens comprises a first liquid crystal adjustable-focus lens unit and a second liquid crystal adjustable-focus lens unit which are stacked along an optical axis, a double-layer independent driving interface for outputting a first driving control quantity and a second driving control quantity respectively, a phase resetting differentiation structure for staggering the Fresnel phase resetting radius set, the blaze height distribution or the partition boundary profile of the two lens units from each other, a lamination packaging structure for forming a controlled lamination gap between the two lens units and providing a buffer, sealing and blocking in an edge packaging area. Through the double-layer near-quadrature orientation, independent driving compensation, controlled lamination thickness and stress management and phase resetting staggering, the polarization-related error under natural light conditions is reduced, and interlayer scattering, moire and resetting boundary artifacts are inhibited, and the lens is suitable for smart adjustable-focus glasses, AR / VR and portable optical imaging systems.

Description

Technical Field

[0001] This invention relates to the field of adjustable focus lenses, and particularly to polarization-insensitive adjustable focus lenses of orthogonal double-layer lenses and their bonding and packaging methods. Background Technology

[0002] Liquid crystal focusing lenses have become core optical components in smart glasses, AR / VR optical systems, and portable imaging devices due to their advantages such as no mechanical movement, fast response, thinness, and low power consumption. However, traditional monolithic liquid crystal lenses are inherently anisotropic optical devices, and their phase modulation and diopter adjustment effects are highly dependent on the polarization direction of the incident light. Under conditions of unpolarized light incident, such as natural light or ambient stray light, significant polarization sensitivity defects will appear, directly affecting image quality and wearing experience.

[0003] In existing technologies, the mainstream solutions for mitigating the polarization dependence problem of liquid crystal lenses have the following significant shortcomings: Adding a linear polarizer: While it can unify the incident polarization state and reduce polarization sensitivity, it will significantly reduce light transmittance, causing brightness loss and color shift. At the same time, it will increase the total thickness of the lens, which violates the requirements of thin and light design, and will also aggravate visual fatigue when wearing it.

[0004] Complex optical compensation structures: Polarization compensation using multilayer film systems, waveplate combinations, or special liquid crystal materials can improve some polarization errors, but the process steps are cumbersome, the material costs are high, the interlayer assembly accuracy requirements are extremely high, and the mass production yield and reliability are difficult to guarantee, which cannot meet the needs of large-scale applications.

[0005] Single structure optimization: Simply improving the alignment process or electrode design cannot eliminate polarization crosstalk in principle. Residual polarization sensitivity will still cause problems such as refractive power drift, aberration distortion, and blurred field of view edges.

[0006] Defects in interlayer bonding and encapsulation: The lack of thickness and stress control in the double-layer stacking scheme can easily lead to interlayer scattering, birefringence distortion, and moiré interference; the synchronous superposition of Fresnel phase reset boundaries can produce obvious visible artifacts, further degrading the imaging effect.

[0007] In summary, the current field of adjustable-focus glasses and liquid crystal optics urgently needs a dual-layer liquid crystal lens structure and matching packaging method that is polarization-insensitive, thin, reliable, and highly mass-producible, while also possessing low aberration and low artifact characteristics, in order to overcome the multiple contradictions of existing technologies in terms of optical performance, structural processes, and mass production costs. Summary of the Invention

[0008] The core of this invention lies in solving the problems of polarization sensitivity, unstable imaging under natural light, reduced transmittance and increased thickness due to reliance on polarizers, scattering and moiré patterns caused by bonding stress, and visible artifacts at the phase reset boundary in existing technologies by stacking orthogonal double-layer lenses, independently driving and fine-tuning dual lenses, controlling bonding thickness and stress, and misaligning Fresnel phase reset.

[0009] To solve the above problems, the present invention adopts the following technical solution.

[0010] A polarization-insensitive adjustable focusing lens for orthogonal double-layer lenses, comprising: The first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit are stacked along the optical axis to form a double-layer structure. The first liquid crystal adjustable focus lens unit has a first orientation direction a1, the second liquid crystal adjustable focus lens unit has a second orientation direction a2, and the included angle between a1 and a2 satisfies |∠(a1,a2)-90°|≤δ; The dual-layer independent drive interface is used to output a first drive control quantity u1 and a second drive control quantity u2 to the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit respectively, so as to realize independent fine adjustment, electrical testing and calibration. The dual-layer independent drive interface includes two sets of independent electrical connection pads and flexible lead-out structures, so that the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit can perform electrical testing and calibration respectively. A phase-reset differentiation structure is used to make the first liquid crystal adjustable lens unit and the second liquid crystal adjustable lens unit differ in at least one of the Fresnel phase-reset radius set, blaze height distribution and partition boundary profile, thereby reducing stripes, moiré interference and visible artifacts caused by stacking; The bonding and packaging structure is used to form a controlled bonding gap between the first liquid crystal adjustable lens unit and the second liquid crystal adjustable lens unit, and to provide stress buffering.

[0011] Furthermore, the phase reset differentiation structure includes a first phase reset radius set {r_z^(1)} and a second phase reset radius set {r_z^(2)}, and satisfies r_z^(1)≠r_z^(2) at at least one index z, so that the two lens units do not undergo synchronous phase reset at the corresponding radii.

[0012] Furthermore, the bonding and packaging structure includes an optically transparent adhesive layer disposed between the opposing surfaces of the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit and located within the effective light transmission area, and a compliant buffer layer disposed circumferentially outside the optically transparent adhesive layer and located at the edge region of the opposing surfaces. The compliant buffer layer is used to reduce residual stress caused by bending or thermal cycling.

[0013] Furthermore, the dual-layer independent drive interface includes two sets of independent electrical connection pads and flexible lead-out structures, so that the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit can be electrically tested and calibrated respectively.

[0014] Furthermore, the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit have at least one of the following settings: liquid crystal layer gap thickness, material birefringence Δn, and response time constant, in order to extend the effective refractive power range and improve dynamic response.

[0015] Furthermore, the bonding and packaging structure also includes a peripheral sealing frame forming a closed loop around the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit, and a moisture barrier layer covering the outside of the peripheral sealing frame and / or extending to the outer surface of the upper and lower substrates, so as to improve the reliability of sweat resistance and damp heat resistance.

[0016] Furthermore, it also includes a field-of-view control structure to limit or compensate for phase errors under large incident angle conditions so that the effective field of view meets a preset threshold.

[0017] Furthermore, it also includes temperature sensors and temperature compensation parameters disposed in the packaging area around or near the edge of the two lens units. The temperature compensation parameters are used to correct the first drive control quantity u1 and the second drive control quantity u2 according to the measured temperature.

[0018] Furthermore, the orientation error δ between the first orientation direction a1 and the second orientation direction a2 is no greater than 3°.

[0019] A bonding and encapsulation method for a polarization-insensitive adjustable focusing lens of an orthogonal double-layer lens includes the following steps: S1. Provide a first liquid crystal adjustable focus lens unit and a second liquid crystal adjustable focus lens unit respectively, and make their orientation directions approximately orthogonal; S2. Based on the phase reset differential structure, the first liquid crystal adjustable lens unit and the second liquid crystal adjustable lens unit are set to have at least one difference in phase reset radius, flare height and partition boundary; S3. An optically transparent adhesive layer is provided in the effective light-transmitting area to bond the two lens units and form a controlled bonding gap. A flexible buffer layer is provided on the outer periphery of the optically transparent adhesive layer, and a peripheral sealing frame and a moisture barrier layer are formed in the peripheral encapsulation area. S4. Perform electrical tests, wavefront calibration, and diopter calibration on the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit respectively to obtain the first mapping relationship and the second mapping relationship; S5. Under non-polarized light conditions, jointly calibrate the first driving control quantity u1 and the second driving control quantity u2, and call the corresponding temperature compensation model according to the real-time temperature to make the total refractive power meet the target value and minimize the polarization-related error. S6. After completing the joint calibration, pre-curing and final curing of the bonding components are performed to complete the encapsulation and curing.

[0020] Furthermore, in step S5, the weighted sum of the total refractive error and the polarization-related error is used as the objective function.

[0021] Among them, polarization-related error is the fluctuation of output refractive power or output wavefront under different incident polarization states.

[0022] Furthermore, in step S3, a compliant buffer layer is used to control the bonding stress, so that the wavefront drift under bending radius or thermal cycling conditions is less than a threshold.

[0023] Furthermore, in step S4, temperature compensation models for the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit are established respectively, and the first drive control quantity u1 and the second drive control quantity u2 are corrected according to the real-time temperature.

[0024] Furthermore, the phase reset difference in step S2 is selected such that the first liquid crystal adjustable lens unit and the second liquid crystal adjustable lens unit do not undergo synchronous phase reset at the same radius.

[0025] Compared with the prior art, the advantages of this invention are: (1) This scheme does not require an additional polarizer, which can significantly reduce the influence of the polarization state of the incident light on the refractive power and wavefront, and maintain imaging stability in natural light and stray light environments; at the same time, by eliminating the polarizer and complex compensation layer, the overall thickness is thinner and the light flux is higher.

[0026] (2) The two liquid crystal lens units can be driven independently, effectively compensating for material differences, process errors, temperature drift and residual polarization crosstalk, significantly improving yield, consistency and long-term reliability.

[0027] (3) By setting an optically transparent adhesive layer in the effective light-transmitting area, setting a compliant buffer layer on its circumferential outer side, and setting a closed-loop sealing frame and a moisture barrier layer in the surrounding encapsulation area, the interlayer thickness, residual stress and environmental reliability can be controlled simultaneously; by setting the Fresnel phase reset radius, blaze height and boundary profile differently, the synchronous superposition of reset boundaries can avoid the generation of stripes and artifacts. Attached Figure Description

[0028] Figure 1 This is a partially enlarged schematic diagram of the orthogonal double-layer liquid crystal lens stacked structure and the edge encapsulation area of ​​the present invention; Figure 2 This is a schematic diagram illustrating the principle of natural light polarization decomposition and orthogonal double-layer compensation of the present invention; Figure 3 This is a schematic diagram of the Jones matrix cascade representation of the present invention; Figure 4 This is a schematic diagram illustrating the Mueller matrix and Stokes vector representation of the present invention; Figure 5 This is a schematic diagram comparing the polarization sensitivity of the present invention (monolayer vs. orthogonal double layer). Figure 6 This is a schematic diagram of the orthogonal orientation reference and alignment layer direction of the present invention; Figure 7 This is a schematic diagram illustrating the effect of orthogonal bonding error on residual polarization sensitivity according to the present invention; Figure 8 This is a schematic diagram of the dual-chip independent drive and cooperative control scheme of the present invention; Figure 9 This is a schematic diagram of the orthogonal double-layer lamination and encapsulation process of the present invention; Figure 10 This is a simulated SEM illustration of the present invention (not a real photograph, but an example of alignment layer trenches / microtextures). Detailed Implementation

[0029] The technical solutions will now be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention.

[0030] First implementation method: like Figure 1 A polarization-insensitive adjustable focusing lens with orthogonal double-layer lenses, comprising: a first liquid crystal adjustable focusing lens unit and a second liquid crystal adjustable focusing lens unit, a dual-layer independent driving interface, a phase reset differential structure, a bonding and packaging structure, a field control structure, and a temperature sensor and temperature compensation parameters. A first liquid crystal adjustable focusing lens unit and a second liquid crystal adjustable focusing lens unit are stacked along the optical axis to form a double-layer structure. The first liquid crystal adjustable focusing lens unit includes, from the center upwards, a first liquid crystal layer, an upper substrate, and an upper protective layer / AR layer. The second liquid crystal adjustable focusing lens unit includes, from the center downwards, a second liquid crystal layer, a lower substrate, and a lower protective layer / AR layer. The first liquid crystal adjustable focusing lens unit and the second liquid crystal adjustable focusing lens unit have at least one of the following settings: liquid crystal layer gap thickness, material birefringence Δn, and response time constant, in order to expand the effective refractive power range and improve dynamic response.

[0031] The first liquid crystal adjustable focus lens unit has a first orientation direction a1, and the second liquid crystal adjustable focus lens unit has a second orientation direction a2, and the included angle between a1 and a2 satisfies |∠(a1,a2)-90°|≤δ; furthermore, the orientation error δ between the first orientation direction a1 and the second orientation direction a2 is not greater than 3°.

[0032] The dual-layer independent drive interface is used to output the first drive control quantity u1 and the second drive control quantity u2 to the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit respectively, so as to realize independent fine adjustment, electrical testing and calibration. The dual-layer independent drive interface includes two sets of independent electrical connection pads and flexible lead-out structures, so that the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit can perform electrical testing and calibration respectively.

[0033] The phase reset differentiation structure is used to make the first liquid crystal adjustable lens unit and the second liquid crystal adjustable lens unit differ in at least one of the Fresnel phase reset radius set, blaze height distribution and partition boundary profile, thereby reducing the stripes, moiré interference and visible artifacts caused by stacking; the phase reset differentiation structure includes the first phase reset radius set {r_z^(1)} and the second phase reset radius set {r_z^(2)}, and satisfies r_z^(1)≠r_z^(2) at at least one index z, so that the two lens units do not undergo synchronous phase reset at the corresponding radii; The bonding and encapsulation structure is used to form a controlled bonding gap between the first and second liquid crystal adjustable lens units and to provide stress buffering, peripheral sealing, and environmental barrier. Specifically, an optically transparent adhesive layer is provided between the opposing surfaces of the first and second liquid crystal adjustable lens units, within the effective light-transmitting area; a compliant buffer layer is provided on the circumferential outer side of the optically transparent adhesive layer, at the edge region of the opposing surfaces; and a closed-loop peripheral sealing frame is formed along the periphery of the two lens units. A moisture barrier layer is covered on the outer side of the peripheral sealing frame and / or extending to the outer peripheral surfaces of the upper and lower substrates to improve sweat resistance and damp heat resistance reliability.

[0034] The field-of-view control structure is used to limit or compensate for phase errors under large incident angle conditions so that the effective field of view meets a preset threshold. In one embodiment, the orientation error δ between the first orientation direction a1 and the second orientation direction a2 can be controlled within 3° to further reduce residual polarization sensitivity.

[0035] In one embodiment, a temperature sensor is also provided in the packaging area around the two lens units or near the edge area. The temperature compensation parameter is used to correct the first drive control quantity u1 and the second drive control quantity u2 according to the measured temperature, so as to reduce the refractive error caused by temperature drift.

[0036] A bonding and encapsulation method for a polarization-insensitive adjustable focusing lens of an orthogonal double-layer lens includes the following steps: S1. Provide a first liquid crystal adjustable focus lens unit and a second liquid crystal adjustable focus lens unit respectively, and make their orientation directions approximately orthogonal; S2. Based on the phase reset differential structure, the first liquid crystal adjustable lens unit and the second liquid crystal adjustable lens unit are set to have at least one difference in phase reset radius, flare height and partition boundary, wherein the phase reset difference is selected to make the first liquid crystal adjustable lens unit and the second liquid crystal adjustable lens unit not undergo synchronous phase reset at the same radius. S3. An optically transparent adhesive layer is set in the effective light-transmitting area to bond the two lens units and form a controlled bonding gap. A flexible buffer layer is set on the outer periphery of the optically transparent adhesive layer, and a peripheral sealing frame and a moisture barrier layer are formed in the peripheral encapsulation area. S4. Perform electrical tests, wavefront calibration, and diopter calibration on the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit respectively to obtain the first mapping relationship and the second mapping relationship. In addition, establish temperature compensation models for the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit respectively, and correct the first driving control quantity u1 and the second driving control quantity u2 according to the real-time temperature. S5. Under non-polarized light conditions, jointly calibrate the first driving control quantity u1 and the second driving control quantity u2, and call the corresponding temperature compensation model according to the real-time temperature to make the total refractive power meet the target value and minimize the polarization-related error. Specifically, the weighted sum of the total refractive power error and the polarization-related error is used as the objective function, where the polarization-related error is the fluctuation of the output refractive power or output wavefront under different incident polarization states.

[0037] S6. After completing the joint calibration, pre-curing and final curing of the bonding components are performed to complete the encapsulation and curing.

[0038] like Figure 2 In practical implementation, regarding the polarization sensitivity of a single liquid crystal lens (background model): If a single liquid crystal lens unit is approximated as a linear phase retarder, its Jones matrix can be expressed as: J(δ,ψ)=R(-ψ)·diag(e^(jδ / 2), e^(-jδ / 2))·R(ψ), where R(ψ) is the fast axis rotation matrix.

[0039] Where δ is the phase delay, ψ is the direction of the fast axis, and δ is related to the driving voltage V and the radial position r; for example Figure 5 For natural light with different incident polarization angles α, the output phase or equivalent refractive power will produce significant differences.

[0040] like Figure 6 Regarding the polarization insensitivity of orthogonal double-layer stacks: Two liquid crystal cells are stacked nearly orthogonally. The second cell is rotated 90° relative to the first, allowing for a small orthogonality error ε. The total Jones matrix can then be expressed as: J_tot=J(δ2,ψ1+90°+ε)·J(δ1,ψ1).

[0041] In the formula, δ1 and δ2 are the phase delays of the first liquid crystal adjustable lens unit and the second liquid crystal adjustable lens unit, respectively, ψ1 is the fast axis direction of the first liquid crystal adjustable lens unit, and ε is the relative 90° orthogonal orientation error. Figure 3 The matrix relationship after two units are cascaded is shown.

[0042] When the two phase delays are independently fine-tuned to achieve matching, the sensitivity of the total equivalent phase Φ to the incident polarization angle α is significantly reduced, and the following engineering criterion can be adopted: | Φ / α|≤τ_pol.

[0043] Where Φ is the total equivalent phase, α is the incident polarization angle, and τ_pol is the allowable polarization correlation error threshold; Figure 3 This indicates that cascading and independent fine-tuning can reduce polarization-dependent errors.

[0044] Criteria for Mueller / Stokes projects: The system is written as a Mueller matrix M, and the incident or output polarization state is represented by a Stokes vector S: S_out = M·S_in.

[0045] Where S = [I, Q, U, V]^T; I represents the total light intensity, Q and U represent the linear polarization components, and V represents the circular polarization component.

[0046] The output linear polarization degree DOLP=sqrt(Q^2+U^2) / I can be used as an engineering indicator of polarization insensitivity.

[0047] By comparing the variation range of DOLP under different first driving control quantities u1, second driving control quantities u2, and different incident polarization states, the polarization robustness of the double-layer structure can be evaluated.

[0048] Figure 4 The evaluation results based on the Mueller matrix and Stokes vector are shown, and it can be seen that the output fluctuation range of the bilayer structure is reduced under different polarization states.

[0049] Regarding rotational error ε and residual polarization error: If there is an error ε in the orthogonality angle, then the residual polarization error E_res can be approximately expressed as: E_res≈K·sin(2ε).

[0050] Where K is a proportionality coefficient related to the device's birefringence, phase matching degree, and measurement conditions.

[0051] Therefore, it is recommended that the orthogonal error ε be no greater than 1°, and further compensation be made through independent fine-tuning of two chips. Figure 7 This indicates that the residual polarization error increases synchronously as the orthogonality error increases.

[0052] Regarding independent drive and coordinated control of dual chips: Two units driven independently ( Figure 8 When this is the case, the following collaborative control relationship can be adopted: u1=k1·u+Δ1(T), u2=k2·u+Δ2(T).

[0053] In the formula, u is the user control quantity, k1 and k2 are gain allocation coefficients, and Δ1(T) and Δ2(T) are compensation terms related to temperature T, which are used to correct for dual-chip mismatch, temperature drift and residual polarization crosstalk.

[0054] Figure 8 The dual-chip independent drive and cooperative control scheme is shown, which can correct the first drive control quantity u1 and the second drive control quantity u2 in real time based on the joint calibration results.

[0055] Regarding bonding stress and interlayer thickness control: The thickness t_OCA of the interlayer optically transparent adhesive layer and the residual stress σ will introduce changes in scattering and birefringence. In engineering, the following approximate relationship can be used: Δn_stress=C·σ.

[0056] Where Δn_stress is the stress-induced birefringence change, C is the stress optical coefficient, and σ is the residual stress; in the process, t_OCA∈[t_min,t_max] and σ≤σ_max are controlled to suppress interlayer scattering and wavefront drift.

[0057] Regarding phase reset misalignment (optional differentiation): If both images use Fresnel phase reset, their reset radius sequences can be set to {r_z^(1)} and {r_z^(2)}, and the overlap of visible artifacts can be reduced by offsetting them. An example constraint is as follows: |r_z^(1)-r_z^(2)|≥Δr_min.

[0058] Wherein, Δr_min is the preset minimum reset radius difference, and z is the reset sequence number; when this condition is met, synchronous phase reset of the two lenses at the same radius can be avoided.

[0059] Figure 9 The bonding and packaging process is shown. Figure 10 The relative positional relationship between phase reset and alignment microtexture is illustrated.

[0060] The above description is merely a preferred embodiment of the present invention; it encompasses all the protection scope of the present invention. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in the present invention, based on the technical solutions and improved concepts of the present invention, should be covered within the protection scope of the present invention.

Claims

1. A polarization-insensitive adjustable focusing lens with orthogonal double-layer lenses, characterized in that, include: The first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit are stacked along the optical axis to form a double-layer structure. The first liquid crystal adjustable focus lens unit has a first orientation direction a1, the second liquid crystal adjustable focus lens unit has a second orientation direction a2, and the included angle between a1 and a2 satisfies |∠(a1,a2)-90°|≤δ; The dual-layer independent drive interface is used to output the first drive control quantity u1 and the second drive control quantity u2 to the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit respectively, so as to realize independent fine adjustment, electrical testing and calibration. A phase-reset differentiation structure is used to make the first liquid crystal adjustable lens unit and the second liquid crystal adjustable lens unit differ in at least one of the Fresnel phase-reset radius set, blaze height distribution and partition boundary profile, thereby reducing stripes, moiré interference and visible artifacts caused by stacking; A bonding and encapsulation structure is used to form a controlled bonding gap between the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit, and to provide stress buffering. The phase reset differentiation structure includes a first phase reset radius set {r_z^(1)} and a second phase reset radius set {r_z^(2)}, and satisfies r_z^(1)≠r_z^(2) at at least one index z, so that the two lens units do not undergo synchronous phase reset at the corresponding radii.

2. The polarization-insensitive adjustable focusing lens of the orthogonal double-layer lens according to claim 1, characterized in that, The bonding and encapsulation structure includes an optically transparent adhesive layer disposed between the opposing surfaces of the first liquid crystal adjustable lens unit and the second liquid crystal adjustable lens unit and located within the effective light-transmitting area, and a compliant buffer layer disposed circumferentially outside the optically transparent adhesive layer and located at the edge region of the opposing surfaces. The compliant buffer layer is used to reduce residual stress caused by bending or thermal cycling.

3. The polarization-insensitive adjustable focusing lens of the orthogonal double-layer lens according to claim 2, characterized in that, The dual-layer independent drive interface includes two sets of independent electrical connection pads and flexible lead-out structures, so that the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit can be electrically tested and calibrated respectively.

4. The polarization-insensitive adjustable focusing lens of the orthogonal double-layer lens according to claim 3, characterized in that, The first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit have at least one of the following settings: liquid crystal layer gap thickness, material birefringence Δn, and response time constant, in order to expand the effective refractive power range and improve dynamic response.

5. The polarization-insensitive adjustable focusing lens of the orthogonal double-layer lens according to claim 4, characterized in that, The bonding and packaging structure also includes a peripheral sealing frame that forms a closed loop around the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit, and a moisture barrier layer that covers the outside of the peripheral sealing frame and / or extends to the outer surface of the upper and lower substrates to improve sweat resistance and damp heat resistance reliability.

6. The polarization-insensitive adjustable focusing lens of the orthogonal double-layer lens according to claim 5, characterized in that, It also includes a field-of-view control structure to limit or compensate for phase errors under large incident angle conditions so that the effective field of view meets a preset threshold.

7. The polarization-insensitive adjustable focusing lens of the orthogonal double-layer lens according to claim 6, characterized in that, The orientation error δ between the first orientation direction a1 and the second orientation direction a2 is no greater than 3°.

8. The polarization-insensitive adjustable focusing lens of the orthogonal double-layer lens according to claim 7, characterized in that, It also includes a temperature sensor disposed in the surrounding packaging area or near the edge area of ​​the first liquid crystal adjustable lens unit and the second liquid crystal adjustable lens unit, and temperature compensation parameters for correcting the first drive control quantity u1 and the second drive control quantity u2 according to the measured temperature.

9. The polarization-insensitive adjustable focusing lens of the orthogonal double-layer lens according to claim 8, characterized in that, Its bonding and encapsulation method includes the following steps: S1. Provide a first liquid crystal adjustable focus lens unit and a second liquid crystal adjustable focus lens unit respectively, and make their orientation directions approximately orthogonal; S2. Based on the phase reset differential structure, the first liquid crystal adjustable lens unit and the second liquid crystal adjustable lens unit are set to have at least one difference in phase reset radius, flare height and partition boundary; S3. An optically transparent adhesive layer is provided in the effective light-transmitting area to bond the two lens units and form a controlled bonding gap. A flexible buffer layer is provided on the outer periphery of the optically transparent adhesive layer, and a peripheral sealing frame and a moisture barrier layer are formed in the peripheral encapsulation area. S4. Perform electrical tests, wavefront calibration, and diopter calibration on the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit respectively to obtain the first mapping relationship and the second mapping relationship, and establish temperature compensation models for the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit respectively. S5. Under non-polarized light conditions, jointly calibrate the first driving control quantity u1 and the second driving control quantity u2, and call the corresponding temperature compensation model according to the real-time temperature to make the total refractive power meet the target value and minimize the polarization-related error. S6. After completing the joint calibration, pre-curing and final curing of the bonding components are performed to complete the encapsulation and curing.

10. The polarization-insensitive adjustable focusing lens of the orthogonal double-layer lens according to claim 9, characterized in that, In step S5, the weighted sum of the total refractive error and the polarization-related error is used as the objective function, where the polarization-related error is the fluctuation of the output refractive power or the output wavefront under different incident polarization states.

11. The polarization-insensitive adjustable focusing lens of the orthogonal double-layer lens according to claim 9, characterized in that, In step S3, a compliant buffer layer is used to control the bonding stress, so that the wavefront drift under bending radius or thermal cycling conditions is less than the threshold.

12. The polarization-insensitive adjustable focusing lens of the orthogonal double-layer lens according to claim 9, characterized in that, In step S4, temperature compensation models for the first liquid crystal adjustable focus lens unit and the second liquid crystal adjustable focus lens unit are established respectively, and the first drive control quantity u1 and the second drive control quantity u2 are corrected according to the real-time temperature.

13. The polarization-insensitive adjustable focusing lens of the orthogonal double-layer lens according to claim 9, characterized in that, The phase reset difference in step S2 is selected such that the first liquid crystal adjustable lens unit and the second liquid crystal adjustable lens unit do not undergo synchronous phase reset at the same radius.

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