AR / VR module of integrated prescription diffraction lens, assembly calibration method and calibration system

Abstract

The invention discloses an AR / VR module of an integrated prescription diffraction lens, an assembly calibration method and a calibration system, which are applied to the field of AR / VR optical machine system integration and calibration. According to the scheme, the interface structure, the reference surface and the positioning structure are arranged on the mirror frame or the carrier, so that stable assembly between the prescription diffraction lens and the display source, the waveguide or the light combiner is realized; and a closed-loop process is formed through metering before assembly, positioning installation, light path alignment, locking and fixing, calibration and acquisition, error decomposition, compensation writing and acceptance and archiving, so that a traceable data packet comprising a prescription version number, an error vector, a compensation parameter, an acceptance conclusion and a signature abstract is output.

Description

Technical Field

[0001] This invention relates to the field of AR / VR optomechanical system integration and calibration, and particularly to AR / VR modules with integrated prescription diffraction lenses, assembly and calibration methods, and calibration systems. Background Technology

[0002] Augmented reality (AR) and virtual reality (VR) technologies have developed rapidly in recent years, and head-mounted display devices are evolving towards lighter weight, higher image quality, and greater personalization. As the user base expands from early adopters to the mass market, the vision correction needs of users with refractive errors (myopia, hyperopia, astigmatism) have become a key issue that urgently needs to be addressed in the popularization of AR / VR devices.

[0003] Traditional solutions typically employ add-on refractive lenses, which involve superimposing a refractive lens in front of or behind the existing waveguide optical module. However, this design has significant drawbacks: First, the add-on lens increases the size and weight of the optomechanical system, contradicting the trend towards thinner and lighter AR / VR devices; second, aberrations such as chromatic aberration and field curvature from the refractive lens can couple with the waveguide optical system, reducing overall image quality; third, the lack of a precise positioning interface between the add-on lens and the waveguide module makes assembly errors difficult to control, resulting in unstable correction effects with individualized prescriptions.

[0004] In recent years, the technical approach of integrating diffractive optical elements with prescription correction functions has been proposed, namely, directly introducing diffractive lenses with optical power into the optical path. Theoretically, this approach can achieve refractive correction without significantly increasing volume. However, in actual mass production integration, the assembly of prescription diffractive lenses with display sources and waveguide modules faces multiple technical challenges: First, the lack of an optomechanical interface structure leads to insufficient lens positioning accuracy, introducing additional translation and tilt errors; second, the assembly error propagation mechanism is unclear, making it difficult to establish a quantitative mapping from geometric errors to image quality degradation; third, there is a lack of efficient online calibration and compensation methods, making it impossible to correct residual errors after assembly; and fourth, insufficient data consistency and traceability in cross-site production makes it difficult to meet the quality gating requirements of large-scale manufacturing.

[0005] Furthermore, the increasing prevalence of eye-tracking functionality in modern AR / VR devices necessitates prescription lenses with good transmittance in the near-infrared band (such as 850nm / 940nm), which traditional prescription lenses often lack specific optimization for. Simultaneously, issues such as optical system drift caused by temperature variations and recalibration after lens replacement place higher demands on the maintainability and environmental adaptability of the module.

[0006] Integrating prescription diffraction lenses into modules presents challenges such as interface errors, assembly tolerances, temperature drift, and calibration consistency. There is an urgent need for a mass-producible, acceptable, and traceable optomechanical interface and calibration compensation solution. Summary of the Invention

[0007] The core of this invention lies in defining the interface structure such as the reference surface / positioning pin between the lens and the module, and combining it with pre-assembly measurement, optical path alignment, error decomposition (translation / tilt) and compensation LUT writing to achieve prescription correction and waveguide image quality matching.

[0008] To solve the above problems, the present invention adopts the following technical solution.

[0009] An AR / VR module integrating a prescription diffraction lens includes: a display source, a waveguide assembly or beam combiner, a prescription diffraction lens, a frame or carrier, and a module data package; wherein, the module data package is used to record a module acceptance protocol and traceability data organized in a predetermined field order, and the frame or carrier includes an interface structure having a reference surface and a positioning structure for defining the assembly pose of the prescription diffraction lens relative to the waveguide assembly or beam combiner.

[0010] Furthermore, the positioning structure includes at least one of a positioning pin and a snap-fit ​​structure.

[0011] Furthermore, the prescription diffraction lens is a module that can be replaced according to prescription requirements.

[0012] Furthermore, the prescription diffractive lens has transmittance that meets eye-tracking requirements at at least one near-infrared operating wavelength, between 850 nm and 940 nm.

[0013] Furthermore, the module data package includes the prescription version number and hash digest.

[0014] Furthermore, the module data package also includes a signature field, audit logs, compensation LUT version, and acceptance conclusions.

[0015] Furthermore, the interface structure limits the translation tolerance threshold and the tilt tolerance threshold.

[0016] Furthermore, the module acceptance protocol should include at least the interface error threshold, aberration index threshold, and near-infrared transmittance threshold.

[0017] An assembly and calibration method for an AR / VR module integrating prescription diffraction lenses includes: acquiring prescriptions and design packages, pre-assembly measurement, positioning and installation, optical path alignment, locking and fixing, calibration acquisition, error decomposition and compensation writing, and generating an acceptance report and signing and archiving.

[0018] Furthermore, the error decomposition yields the interface error vector e=[Δx,Δy,Δα,Δβ]^T.

[0019] Furthermore, the alignment target in the optical path alignment process is to minimize the aberration evaluation function.

[0020] Furthermore, the acceptance report includes a pass / fail conclusion and a traceability field.

[0021] Furthermore, after assembly, image plane drift or aberration drift occurs at different temperature points, which is called temperature drift. Temperature drift is corrected by thermal compensation parameters.

[0022] Furthermore, the thermal compensation parameters are updated with temperature sampling points and used to correct at least one of the compensation LUT and pre-distortion parameters.

[0023] Furthermore, the compensation write simultaneously updates the displayed pre-distortion parameters and / or optical control parameters.

[0024] Furthermore, the calibration results are written into the standardized module data packet according to the predetermined field order.

[0025] Furthermore, assembly calibration records are written into the audit chain for traceability.

[0026] A calibration system for an assembly calibration method of an AR / VR module with integrated prescription diffraction lenses includes: a test pattern or display source, a camera or sensor, a data processing module, and a compensation writing module.

[0027] Furthermore, the calibration system acquires near-infrared detection images to verify the transmission status of the prescription diffraction lens at the near-infrared working wavelength.

[0028] Compared with the prior art, the advantages of this invention are: (1) Compact and lightweight: It uses diffraction optics technology to achieve refractive correction without the need for additional refractive lenses, which significantly reduces the module volume and weight and improves wearing comfort.

[0029] (2) High assembly accuracy and improved yield: Through the mechanical interface of the reference surface / positioning pin and the closed-loop alignment process, the assembly error is controlled at the sub-pixel level, reducing the stringent requirements on the tolerance of parts and improving the mass production yield.

[0030] (3) Precise image quality compensation and excellent visual experience: Based on error decomposition, the compensation LUT writing can perform customized correction for individual assembly errors, effectively eliminating astigmatism, distortion and image plane offset caused by assembly, and presenting a clear and stable virtual image.

[0031] (4) Strong eye-tracking compatibility: The prescription lens is designed to have high transmittance in the 850 / 940nm near-infrared band, ensuring sufficient signal strength when the eye-tracking camera captures eye images through the prescription lens, thus improving the robustness and accuracy of eye-tracking.

[0032] (5) Good environmental adaptability and maintainability: The temperature drift compensation mechanism ensures the imaging consistency of the equipment in a wide temperature range; the replaceable lens module design allows users to flexibly replace the lens according to changes in prescription or different usage scenarios, extending the product life cycle.

[0033] (6) Data traceability and quality control: The standardized data packet format and hash signature mechanism provide a unified acceptance basis and audit tracking capability for multi-site collaborative production, meeting the compliance requirements of fields such as medical devices. Attached Figure Description

[0034] Figure 1 This is a schematic diagram showing the assembly relationship between the AR / VR module and the Air Lens of the present invention; Figure 2 This is a schematic diagram of the optical path of the present invention: display-waveguide-prescription diffraction lens-human eye; Figure 3 This is a schematic diagram of the optical-mechanical interface of the present invention: reference surface / positioning pin / snap fastener structure; Figure 4 This is a schematic diagram of the assembly-calibration-compensation process of the present invention; Figure 5 This is a schematic diagram of the calibration and acquisition device of the present invention; Figure 6 Error decomposition of the present invention: Schematic diagram of translation and tilt; Figure 7 This is a schematic diagram of the compensation mapping of the present invention: from field coordinates to correction LUT; Figure 8 This is a schematic diagram of the in-situ measurement / eye-tracking-assisted compensation update of the present invention; Figure 9 This is a schematic diagram of the module data package and traceability fields of the present invention; Figure 10 This is a schematic diagram illustrating the temperature drift caused by temperature changes in this invention. Figure 11 For the maintainability of this invention: a schematic diagram of a replaceable prescription diffraction lens module. Detailed Implementation

[0035] The technical solutions will now be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention.

[0036] First implementation method: like Figures 1-2An AR / VR module integrating a prescription diffractive lens is disclosed, comprising: a display source (display screen or projection source), a waveguide assembly or beam combiner, a prescription diffractive lens, a frame or carrier, and a module data package; wherein, AirLens is a non-limiting name for the prescription diffractive lens. The module data package is used to record the module acceptance protocol and traceability data organized according to a predetermined field order. The module acceptance protocol (i.e., the acceptance report in the assembly calibration method below) includes at least an interface error threshold, an aberration index threshold, and a near-infrared transmittance threshold. The module data package includes at least a prescription version number, a hash digest, a compensation LUT version, an acceptance conclusion, a signature field, and an audit log to support cross-batch traceability.

[0037] like Figure 3 The frame or carrier includes an interface structure defining translational and tilt tolerance thresholds. The interface structure has a reference plane and a positioning structure for defining the assembly pose of the prescription diffracting lens relative to the waveguide assembly or beam combiner. The positioning structure includes at least one of a positioning pin and a snap-fit ​​structure. Figure 3 In this embodiment, a positioning pin is selected. In specific implementation, before assembly, the state of the reference surface, the position of the positioning pin, and the reference of the lens edge are measured by a camera or sensor to obtain the initial value before assembly. Then, the prescription diffraction lens is installed on the interface structure of the frame or carrier. The interface structure restricts the translational and tilting degrees of freedom of the prescription diffraction lens relative to the waveguide assembly or beam combiner.

[0038] Prescription diffraction lenses are modules that can be replaced according to prescription requirements, such as... Figure 11 The replaceability of the Air Lens module is illustrated. The prescription diffractive lens has transmittance that meets eye-tracking requirements at at least one near-infrared operating wavelength, either 850 nm or 940 nm. For near-infrared compatibility, this embodiment uses two operating wavelengths, 850 nm and 940 nm, as examples. "Transmittance that meets eye-tracking requirements" means that at at least one target near-infrared wavelength, the transmittance of the prescription diffractive lens is not lower than a preset threshold, such as 70%, or a higher threshold given by the requirements of the entire eye-tracking module. This requirement does not mean that the same transmittance is met across the entire continuous band from 850 nm to 940 nm, but rather that it is verified for one or two discrete operating wavelengths.

[0039] An assembly and calibration method for an AR / VR module integrating prescription diffraction lenses includes: acquiring prescriptions and design packages, pre-assembly measurement, positioning and installation, optical path alignment, locking and fixing, calibration acquisition, error decomposition and compensation writing, and generating an acceptance report and signature archiving, such as... Figure 4 The diagram illustrates the sequence of steps for assembly, calibration, and compensation writing.

[0040] Error decomposition yields the interface error vector e = [Δx, Δy, Δα, Δβ]^T, where Δx represents the lateral translation error in the first reference plane, Δy represents the longitudinal translation error in the second reference plane, Δα represents the tilt angle error around the first axis of rotation, Δβ represents the tilt angle error around the second axis of rotation, and T represents the vector transpose. This interface error vector is used to uniformly characterize interface assembly deviations. Figure 6 The decomposition method of translation and tilt errors is shown.

[0041] Image plane drift or aberration drift occurs at different temperature points after assembly, known as temperature drift. Temperature drift is corrected using thermal compensation parameters, which are updated with temperature sampling points and used to correct the compensation LUT and / or pre-distortion parameters, such as... Figure 10 The image plane shift caused by temperature drift and the relationship between thermal compensation are shown.

[0042] The alignment objective during the optical path alignment process is to minimize the aberration evaluation function; the acceptance report includes a pass / fail conclusion and a traceability field. The module data package must include at least the prescription version number, hash digest, compensated LUT version, acceptance conclusion, signature field, and audit log to support cross-batch traceability, such as... Figure 9 The module data packet fields and traceability information are shown.

[0043] The calibration results are written into the standardized module data package in the order of predetermined fields; the assembly calibration record is written into the audit chain for traceability.

[0044] Specifically, such as Figure 3 Initial positioning is achieved using reference plane A and positioning pins. During the alignment phase, the goal is to minimize the aberration evaluation function, which can be exemplified by J(Δq) = Σ_{θ∈Θ}||y_meas(θ,Δq)-y_ref(θ)||_2^2. Here, Δq represents the pose control quantity to be adjusted; θ represents the field sampling angle; Θ represents the sampled field set; y_meas(θ,Δq) represents the imaging evaluation quantity measured at field angle θ when the pose adjustment is Δq; y_ref(θ) represents the design reference quantity; and ||·||_2 represents the L2 norm. By minimizing J, optical path alignment and aberration suppression can be achieved.

[0045] A linear / nonlinear regression is performed on the interface error vector e to obtain the compensation LUT: [Δ(θ)=g(e,θ)], and the LUT is written into the module data packet field. Here, Δ(θ) represents the compensation amount written at the field of view θ; g(·) represents the mapping function that calculates the compensation amount based on the error vector e and the field of view θ. This mapping function can be implemented using linear regression, multinomial regression, or a lookup table. Finally, the compensation LUT is generated and written into the module data packet, as shown below. Figure 7 The mapping relationship between field coordinates and compensation LUT is shown.

[0046] like Figure 5 A calibration system for an assembly calibration method of an AR / VR module integrating prescription diffractive lenses includes: a test pattern or display source, a camera or sensor, a data processing module, and a compensation writing module; the calibration system acquires near-infrared detection images to verify the transmission state of the prescription diffractive lenses at near-infrared working wavelengths.

[0047] Optionally, the above assembly calibration method can also be implemented by a computer program, wherein the computer program can further realize deterministic export and versioning; this content is only an optional implementation in the embodiments and is not protected as an independent claim.

[0048] 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. An AR / VR module integrating prescription diffraction lenses, characterized in that, include: The display source, waveguide assembly or beam combiner, prescription diffractive lens, frame or carrier, and module data package; wherein, the module data package is used to record module acceptance protocol and traceability data organized in a predetermined field order, and the frame or carrier includes an interface structure having a reference surface and a positioning structure for defining the assembly pose of the prescription diffractive lens relative to the waveguide assembly or beam combiner.

2. The AR / VR module with integrated prescription diffraction lenses according to claim 1, characterized in that, The positioning structure includes at least one of a positioning pin and a snap-fit ​​structure.

3. The AR / VR module with integrated prescription diffraction lenses according to claim 1, characterized in that, The prescription diffraction lens is a module that can be replaced according to prescription requirements.

4. The AR / VR module with integrated prescription diffraction lenses according to claim 1, characterized in that, The prescription diffractive lens has transmittance that meets eye-tracking requirements at at least one near-infrared working wavelength between 850 nm and 940 nm.

5. The AR / VR module with integrated prescription diffraction lenses according to claim 1, characterized in that, The module data packet includes a prescription version number and a hash digest.

6. The AR / VR module with integrated prescription diffraction lenses according to claim 5, characterized in that, The module data package also includes a signature field, audit logs, compensation LUT version, and acceptance conclusions.

7. The AR / VR module with integrated prescription diffraction lenses according to claim 1, characterized in that, The interface structure defines translation tolerance thresholds and tilt tolerance thresholds.

8. The AR / VR module with integrated prescription diffraction lenses according to claim 1, characterized in that, The acceptance protocol for the module includes at least the interface error threshold, aberration index threshold, and near-infrared transmittance threshold.

9. An assembly and calibration method for an AR / VR module integrating prescription diffraction lenses, characterized in that, include: The process includes obtaining prescriptions and design packages, pre-assembly measurement, positioning and installation, optical path alignment, locking and fixing, calibration and acquisition, error decomposition and compensation writing, and generating acceptance reports and signature archiving.

10. The assembly and calibration method for an AR / VR module with integrated prescription diffraction lenses according to claim 9, characterized in that, The error decomposition yields an interface error vector e=[Δx,Δy,Δα,Δβ]^T, where Δx represents the lateral translation error in the first reference plane, Δy represents the longitudinal translation error in the second reference plane, Δα represents the tilt angle error around the first axis of rotation, Δβ represents the tilt angle error around the second axis of rotation, and T represents the vector transpose.

11. The assembly and calibration method for an AR / VR module with integrated prescription diffraction lenses according to claim 9, characterized in that, The alignment objective in the optical path alignment process is to minimize the aberration evaluation function.

12. The assembly and calibration method for an AR / VR module with integrated prescription diffraction lenses according to claim 9, characterized in that, The acceptance report includes a pass / fail conclusion and a traceability field.

13. The assembly and calibration method for an AR / VR module with integrated prescription diffraction lenses according to claim 9, characterized in that, After assembly, image plane drift or aberration drift occurs at different temperature points, which is called temperature drift. The temperature drift is corrected by thermal compensation parameters.

14. The assembly and calibration method for an AR / VR module with integrated prescription diffraction lenses according to claim 13, characterized in that, The thermal compensation parameters are updated with temperature sampling points and are used to correct at least one of the compensation LUT and pre-distortion parameters.

15. The assembly and calibration method for an AR / VR module with integrated prescription diffraction lenses according to claim 9, characterized in that, The calibration results are written into the standardized module data packet according to the predetermined field order.

16. The assembly and calibration method for an AR / VR module with integrated prescription diffraction lenses according to claim 9, characterized in that, The assembly calibration records are written into the audit chain for traceability.

17. A calibration system for implementing the assembly calibration method of an AR / VR module with integrated prescription diffraction lenses as described in any one of claims 9-16, characterized in that, include: Test pattern or display source, camera or sensor, data processing module and compensation writing module.

18. The calibration system for an AR / VR module with integrated prescription diffraction lenses according to claim 17, characterized in that, The calibration system acquires near-infrared detection images to verify the transmission status of the prescription diffraction lens at the near-infrared working wavelength.

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