AR light machine module, control method thereof and near-eye display device

Abstract

Embodiments of the present application provide an AR light machine module, a control method thereof and a near-eye display device; wherein the AR light machine module comprises a light machine main body, the light machine main body comprising an imaging lens and a display screen; the light machine main body is configured to set a monocular virtual image distance according to a binocular combined image distance of a wearer, so that the difference in diopter between the monocular virtual image distance and the binocular combined image distance is less than or equal to 0.25D.

Description

Technical Field

[0001] This application relates to the field of augmented reality (AR) display technology, specifically to an AR optical engine module and its control method and a near-eye display device, and more particularly to an AR optical engine module and its control method and a near-eye display device that can solve the problems of vergence-accommodation conflict (VAC) and thermal defocusing of the optical engine system. Background Technology

[0002] In augmented reality (AR) near-eye display devices, optical display systems combining optical engines and waveguides have become the mainstream solution. However, these devices commonly suffer from vergence-accommodation conflict (VAC), which occurs when the binocular convergence distance (corresponding to the convergence of the wearer's eyes) differs from the monocular virtual image distance (corresponding to the accommodation of the monocular lens), leading to discomfort such as visual fatigue, headaches, and even dizziness.

[0003] In traditional AR near-eye display devices, due to the limitations of the coupling conditions of optical waveguide components, the virtual image distance of a single-eye optical engine module is usually designed to be infinite, while the binocular convergence distance is usually designed to be a fixed value (approximately 1.5m to 4m). The difference in refractive power between the two causes convergence conflict. Therefore, there is an urgent need for an AR optical engine module that can solve the user's convergence conflict problem. Summary of the Invention

[0004] The purpose of this application is to provide a new technology solution for an AR optical engine module and its control method and a near-eye display device, which aims to eliminate or reduce convergence conflict by adjusting the monocular virtual image distance according to the wearer's binocular fusion distance, so that the difference in refractive power between the monocular virtual image distance and the binocular fusion distance is less than or equal to 0.25D.

[0005] In a first aspect, this application provides an AR optical engine module, including an optical engine body, wherein the optical engine body includes an imaging lens and a display screen; The optical engine body is configured to set its monocular virtual image distance according to the wearer's binocular fusion distance, so that the difference in refractive power between the monocular virtual image distance and the binocular fusion distance is less than or equal to 0.25D.

[0006] Optionally, the AR optical engine module further includes a focusing mechanism connected to the optical engine body. The focusing mechanism is used to adjust the monocular virtual image distance of the optical engine body according to the binocular fusion distance of the wearer, so that the difference in refractive power between the monocular virtual image distance and the binocular fusion distance is less than or equal to 0.25D.

[0007] Optionally, the matching relationship between the binocular image distance and the monocular virtual image distance satisfies the following formula: 1 / u = 1 / v + D, where u is the binocular image distance of the wearer, v is the monocular virtual image distance of the optical engine, and D is the lens diopter.

[0008] Optionally, the focusing mechanism includes a driving unit disposed between the display screen and the imaging lens, for driving the display screen to change its relative position with the imaging lens along the optical axis.

[0009] Optionally, the imaging lens includes at least one movable lens or at least one group of movable lenses, and the focusing mechanism includes a driving unit connected to the movable lens or the group of movable lenses for driving the movable lens or the group of movable lenses to move along the optical axis to change the air gap between the movable lens or the group of movable lenses and other lenses in the imaging lens.

[0010] Optionally, the driving unit is any one of a piezoelectric ceramic driver, a voice coil motor, or a shape memory alloy driver.

[0011] Optionally, the AR optical engine module further includes an eye-tracking module, which is used to track the wearer's gaze point position in real time and calculate the binocular fusion distance based on the gaze point position.

[0012] Optionally, the AR optical engine module further includes a control module, which is connected to the eye-tracking module and the focusing mechanism respectively. The control module is used to calculate the target monocular virtual image distance based on the binocular fusion distance, control the focusing mechanism to perform an adjustment action to adjust the monocular virtual image distance of the optical engine body to the target monocular virtual image distance, and after adjustment, determine whether the refractive error difference between the current monocular virtual image distance and the binocular fusion distance is less than or equal to 0.25D. If not, iterative adjustment continues until the refractive error difference is less than or equal to 0.25D.

[0013] Optionally, the AR optical engine module further includes a temperature sensor for detecting the temperature of the optical engine body.

[0014] Optionally, the control module is further configured to perform thermal defocus compensation on the target monocular virtual image distance based on the temperature of the optical engine body, and control the focusing mechanism to perform adjustment actions based on the compensated target monocular virtual image distance.

[0015] Secondly, this application provides a near-eye display device, comprising: A left-eye optical engine module and a right-eye optical engine module, wherein the left-eye optical engine module and / or the right-eye optical engine module are AR optical engine modules as described in the first aspect; A left-eye optical waveguide element and a right-eye optical waveguide element, wherein the left-eye optical waveguide element is optically coupled to the left-eye optical engine module and is used to transmit image light to the wearer's left eye, and the right-eye optical waveguide element is optically coupled to the right-eye optical engine module and is used to transmit image light to the wearer's right eye; The monocular virtual image distances of the left and right optical imaging modules are adjusted independently so that the difference in refractive power between their respective monocular virtual image distances and the binocular fusion distance of the wearer is less than or equal to 0.25D.

[0016] Thirdly, this application provides a control method for an AR optical engine module, including: Obtain the binocular convergence distance of the wearer; Based on the binocular fusion distance, the monocular virtual image distance of the main body of the AR optical engine module is set so that the difference in refractive power between the monocular virtual image distance and the binocular fusion distance is less than or equal to 0.25D; wherein, the main body of the optical engine includes an imaging lens and a display screen.

[0017] Fourthly, this application provides a control method for an AR optical engine module, including: Obtain the binocular convergence distance of the wearer; Based on the binocular image merging distance, the target monocular virtual image distance of the main body of the AR optical engine module is determined. The main body of the optical engine includes an imaging lens and a display screen. The focusing mechanism is controlled to adjust the current monocular virtual image distance of the optical engine body to the target monocular virtual image distance, so that the difference in refractive power between the adjusted monocular virtual image distance and the binocular image combination distance is less than or equal to 0.25D.

[0018] One technical advantage of this application is: The AR optical engine module provided in this application, by configuring the monocular virtual image distance of the optical engine body to match the binocular convergence distance of the wearer and controlling the difference in refractive power between the two within 0.25D, ensures that the wearer's binocular convergence distance and monocular accommodation distance are consistent at the target working distance, thereby eliminating the conditions for convergence conflict from the root and significantly reducing the wearer's visual fatigue, headache, dizziness and other discomfort symptoms.

[0019] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0021] Figure 1 This is a schematic diagram of the AR optical engine module provided in this application; Figure 2 This is a schematic diagram of the structure of an AR optical engine module provided in one embodiment of this application; Figure 3 for Figure 2 A sectional view; Figure 4 This is a schematic diagram of the structure of an AR optical engine module provided in another embodiment of this application; Figure 5 for Figure 4 A sectional view; Figure 6 for Figure 4 Assembly diagram of the movable lens and focusing mechanism; Figure 7 This is a schematic diagram of the structure of a near-eye display device provided in an embodiment of this application; Figure 8 A flowchart illustrating the focusing method of the AR optical engine module provided in this application embodiment.

[0022] Explanation of reference numerals in the attached figures: 1. Optical engine body; 11. Display screen; 12. Imaging lens; 121. Movable lens; 2. Focusing mechanism; 21. Base; 22. Displacement part; 23. Power cable and control cable; 3. Adhesive; 4. Sealant; A. Left eye optical engine module; B. Right eye optical engine module; C. Left eye optical waveguide component; D. Right eye optical waveguide component; 01. Left eye; 02. Right eye. Detailed Implementation

[0023] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0024] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0025] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0026] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0028] The AR optical engine module, its control method, and the near-eye display device provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0029] According to one embodiment of this application, an AR optical engine module is provided, see [link to relevant documentation]. Figure 2 and Figure 4 The system includes an optical engine body 1, which includes an imaging lens 12 and a display screen 11. The optical engine body 1 is configured to set its monocular virtual image distance according to the binocular fusion distance of the wearer, so that the difference in refractive power between the monocular virtual image distance and the binocular fusion distance is less than or equal to 0.25D.

[0030] The optical engine body 1 is the core optical component of the AR optical engine module, used to generate light carrying display image information. Specifically, the optical engine body 1 includes a display screen 11 and an imaging lens 12 disposed in the light path of the display screen 11. The display screen 11 is used to display image content and can be any one of a Micro LED display screen, an LCoS display screen, or a DLP display screen; it can be a full-color optical engine module or a monochrome optical engine module, and this embodiment does not limit this. The imaging lens 12 is used to image the image light emitted from the display screen 11 to form a virtual image with a predetermined virtual image distance.

[0031] See Figure 1 Monocular virtual image distance refers to the distance from the virtual image perceived by a wearer's single eye to the wearer's eye after passing through the AR optical engine module; this is the eye's accommodation distance. Binocular convergence distance refers to the distance from the wearer's gaze point of convergence to the wearer's eye; this is the convergence distance. In binocular vision, the distance between the convergence points of the wearer's eyes is the binocular convergence distance. When the monocular virtual image distance and the binocular convergence distance are inconsistent, convergence conflict occurs. Convergence conflict can cause discomfort symptoms such as visual fatigue, headaches, and even dizziness, affecting the user experience. For example, for a monocular optical engine module, its virtual image distance is usually infinity, at which point the eye's accommodation distance is also infinity, while the binocular convergence distance is usually a finite distance (e.g., 1.5m to 4m). The inconsistency between these two distances results in convergence conflict.

[0032] In this application, the optical engine body 1 is configured to set its monocular virtual image distance according to the binocular focusing distance of the wearer, and to control the difference in refractive power between the two within a range of less than or equal to 0.25D. Refractive power is a physical quantity that measures the degree of convergence or divergence of light, expressed in D (diopter), and its value is the reciprocal of the focal length (in meters).

[0033] Studies have found that when the difference in refractive power between convergence distance (the distance between the two eyes) and accommodation distance (the distance between the two eyes) exceeds 0.25D, wearers will experience significant visual fatigue, headaches, or dizziness. However, when the difference in refractive power between the two is no more than 0.25D (less than or equal to), the convergence and accommodation of the human visual system can remain largely coordinated, and wearers are less likely to experience discomfort.

[0034] Therefore, setting the refractive error difference threshold to 0.25D can effectively eliminate or reduce convergence conflict while ensuring display effect. Wearers will not perceive obvious convergence conflict, thus avoiding discomfort such as visual fatigue, headache or motion sickness caused by convergence conflict.

[0035] As an optional implementation, the optical engine body 1 may have a preset fixed monocular virtual image distance. Specifically, during the product design phase, the binocular merging distance can be set to a specific value (e.g., the common 2m or 4m) based on the interpupillary distance distribution of the target user group. This value is then used as a design input, and the monocular virtual image distance of the optical engine body 1 is fixedly matched to this set value through optical design, ensuring that the refractive power difference between the monocular virtual image distance and the binocular merging distance is less than or equal to 0.25D. In this implementation, the relative positions of the imaging lens 12 and the display screen 11 along the optical axis are fixed at the factory. This fixed-focus solution is suitable for first-generation products or cost-sensitive products. While ensuring a basic user experience and effectively eliminating or mitigating convergence conflict, it can significantly reduce product structural complexity and production costs (without the need to introduce a focusing mechanism and its supporting control circuitry and software algorithms). For users with different interpupillary distances, products can be categorized into different specifications (e.g., different models designed for different binocular focusing distances such as 2m and 4m), so that the monocular virtual image distance of each model matches the corresponding preset binocular focusing distance, thus adapting to different user groups. Furthermore, based on the wearer's individual visual acuity, RX lenses and / or VID adjustment lenses can be attached to both sides of the waveguide components to meet refractive correction needs.

[0036] The AR optical engine module provided in this application configuration matches the monocular virtual image distance of the optical engine body 1 with the binocular convergence distance of the wearer, keeping the refractive error difference between the two within 0.25D. This ensures that the wearer's binocular convergence distance and monocular accommodation distance remain consistent at the target working distance, thereby eliminating the conditions for convergence conflict from the root and avoiding discomfort symptoms such as visual fatigue, headaches, or motion sickness caused by convergence conflict.

[0037] In some examples of this application, the AR optical engine module further includes a focusing mechanism 2, which is connected to the optical engine body 1. The focusing mechanism is used to adjust the monocular virtual image distance of the optical engine body 1 according to the binocular fusion distance of the wearer, so that the difference in refractive power between the monocular virtual image distance and the binocular fusion distance is less than or equal to 0.25D.

[0038] In the aforementioned example, the optical engine body 1 has a preset fixed monocular virtual image distance, which is not adjustable after leaving the factory and is suitable for application scenarios where the binocular merging distance is a fixed value. In this example, the AR optical engine module is equipped with a focusing mechanism 2, which is connected to the optical engine body 1 and is used to dynamically adjust the monocular virtual image distance of the optical engine body 1 in real time according to the wearer's binocular merging distance during the use of the near-eye display device.

[0039] Specifically, the focusing mechanism 2 adjusts the virtual image distance by changing the relative positions of the optical elements inside the optical engine body 1. Based on the wearer's current binocular convergence distance (i.e., vergence distance), the focusing mechanism 2 calculates a target monocular virtual image distance that matches this distance, and adjusts the monocular virtual image distance to the target value by driving the corresponding optical elements in the optical engine body 1 (e.g., the display screen 11, specific lenses or lens groups in the imaging lens 12) to ensure that the refractive error difference between the adjusted monocular virtual image distance and the current binocular convergence distance does not exceed 0.25D.

[0040] When the binocular image distance of the wearer changes, for example, because the wearer is looking at real objects at different depths, or because users with different interpupillary distances are wearing the same device, the focusing mechanism 2 can follow the change in real time and adjust the monocular virtual image distance accordingly, so that the monocular virtual image distance and the binocular image distance always remain matched, thereby continuously eliminating convergence conflict in different usage scenarios.

[0041] By adding a focusing mechanism 2, the AR optical engine module in this example achieves dynamic adjustment of the monocular virtual image distance, which can adapt to the usage scenario where the binocular image merging distance changes in real time. It can also adapt to user groups with different interpupillary distances, without the need to divide product specifications for people with different interpupillary distances, and has a wider range of user adaptability and usage flexibility.

[0042] In some examples of this application, the matching relationship between the binocular image distance and the monocular virtual image distance satisfies the following formula: 1 / u = 1 / v + D, where u is the binocular image distance of the wearer, v is the monocular virtual image distance of the optical engine body, and D is the lens diopter.

[0043] In this example of the application, the matching relationship between the binocular convergence distance and the monocular virtual image distance satisfies the lens imaging formula, namely the Gaussian imaging formula: 1 / u = 1 / v + D, where u is the binocular convergence distance in meters, referring to the distance from the wearer's gaze point to the eye, corresponding to the convergence distance; v is the monocular virtual image distance in meters, referring to the distance from the virtual image perceived by the wearer's single eye to the eye, corresponding to the accommodation distance; and D is the lens diopter, referring to the optical power of the lens used by the wearer. For users who do not need to wear refractive corrective lenses, D = 0.

[0044] Based on the above formula, given the wearer's binocular fusion distance u and lens refractive power D, the target monocular virtual image distance v that matches this binocular fusion distance can be calculated. When the monocular virtual image distance of the AR optical engine module is set to this calculated value, the wearer's convergence distance and accommodation distance remain consistent at the target working distance, thereby achieving a match between the convergence distance and accommodation distance and eliminating or mitigating convergence conflict.

[0045] This matching relationship can be applied to the following scenarios: One scenario involves a fixed-focus design. During the product design phase, a fixed value (e.g., 2m or 4m) for the binocular image merging distance is determined based on the target application scenario. The corresponding monocular virtual image distance is then calculated using the formula described above, and the monocular virtual image distance of the main optical engine is fixed to this calculated value through optical design. This scenario is suitable for products with a fixed binocular image merging distance, eliminating the need for a focusing mechanism, and the monocular virtual image distance remains unadjustable after the product leaves the factory.

[0046] Another scenario involves zoom design. During the use of near-eye display devices, for example, an eye-tracking module can acquire the wearer's binocular fusion distance in real time. The control module then dynamically calculates the target monocular virtual image distance according to the aforementioned formula and controls the focusing mechanism to adjust the monocular virtual image distance to that target value in real time. This scenario is suitable for applications where the binocular fusion distance changes in real time.

[0047] See some examples in this application. Figure 2 and Figure 3 The focusing mechanism 2 includes a driving unit, which is disposed between the display screen 11 and the imaging lens 12, and is used to drive the display screen 11 to change its relative position with the imaging lens 12 along the optical axis.

[0048] See Figure 2 and Figure 3 The driving unit of the focusing mechanism 2 is disposed between the display screen 11 and the imaging lens 12, with one side of the driving unit connected to the imaging lens 12 and the other side connected to the display screen 11. The driving unit of the focusing mechanism 2 is used to drive the display screen 11 to displace along the optical axis, thereby changing its relative position with the imaging lens 12, and thus changing the monocular virtual image distance of the AR optical engine module. See also... Figure 2 The drive unit is provided with a power line and a control line 23. The power line and control line 23 are led out from the drive unit body and are used to connect with external circuits such as control modules or power supplies to realize electrical signal control of the drive unit.

[0049] See a specific example in this application. Figure 2 and Figure 3 The driving unit of the focusing mechanism 2 has an initial thickness, which determines the initial gap between the display screen 11 and the imaging lens 12. The driving unit of the focusing mechanism 2 can be an electrically controlled displacement device, such as a piezoelectric ceramic actuator. The driving unit is bonded and fixed to the imaging lens 12 and the display screen 11 using adhesive 3. When the driving unit is driven by an electrical signal, its thickness changes, causing the gap between the display screen 11 and the imaging lens 12 to increase or decrease. This change in gap alters the optical distance of the display screen 11 relative to the imaging lens 12, thereby changing the equivalent focal length and imaging position of the AR optical engine module, and thus achieving adjustment of the monocular virtual image distance.

[0050] It should be noted that during the adjustment process, the movement methods include, but are not limited to, the following: the display screen 11 moves relative to the imaging lens 12 along the optical axis while the imaging lens 12 remains fixed; the imaging lens 12 moves relative to the display screen 11 along the optical axis while the display screen 11 remains fixed; or, the display screen 11 and the imaging lens 12 move simultaneously towards or away from each other along the optical axis. Regardless of the movement method used, as long as the driving unit can drive the display screen 11 and / or the imaging lens 12 to move along the optical axis to change their relative positions, this application does not impose any limitations on this.

[0051] By changing the gap between the display screen 11 and the imaging lens 12 through the driving unit, the imaging position of the AR optical engine module changes accordingly, thereby realizing the adjustment of the monocular virtual image distance.

[0052] See some examples in this application. Figures 4 to 6The imaging lens 12 includes at least one movable lens 121 or at least one group of movable lenses. The focusing mechanism 2 includes a driving unit connected to the movable lens or the group of movable lenses, for driving the movable lens or the group of movable lenses to move along the optical axis to change the air gap between the movable lens or the group of movable lenses and other lenses in the imaging lens.

[0053] In this example of the application, see Figures 4 to 6 This provides a method for changing the monocular virtual image distance by moving the internal lens or lens group of the imaging lens.

[0054] See Figures 4 to 6 The imaging lens 12 includes multiple lenses, including at least one movable lens 121 or at least one group of movable lenses. A movable lens group refers to an assembly of two or more lenses, where the relative positions of the lenses within the group remain constant and the entire assembly moves together. The focusing mechanism 2 includes a drive unit connected to the movable lens 121 or the movable lens group, used to drive the movable lens 121 or the movable lens group to move along the optical axis, thereby changing the air gap between the movable lens 121 or the movable lens group and other lenses in the imaging lens 12. In this example, the drive unit is, for example, an electrically controlled displacement device, including but not limited to a piezoelectric ceramic actuator.

[0055] In this example, the drive unit is located inside the imaging lens 12, and it can replace the spacer ring in the original imaging lens. See also Figure 5 and Figure 6 The drive unit has a base 21, which is interference-fitted with the lens barrel of the imaging lens 12 to position and fix the drive unit within the lens barrel. The drive unit also has a displacement portion 22, which is connected to a movable lens 121 or a movable lens group. When the drive unit is activated by an electrical signal, its displacement portion 22 deforms along the optical axis, causing the connected movable lens 121 or movable lens group to move, thereby changing the air gap between the movable lens 121 or movable lens group and other lenses in the imaging lens 12.

[0056] For example, the movable lens 121 or movable lens group is pre-positioned visually to determine its assembly position in the optical axis direction, and then bonded and fixed to the displacement portion 22 of the drive unit with adhesive 3. To prevent stray light, the periphery of the movable lens 121 can be coated with ink. The power line and control line 23 of the drive unit are led out to the outside of the lens barrel through an opening on the side of the lens barrel for connection to external circuits (such as control modules). After assembly, the opening on the side of the lens barrel is sealed with sealant 4 to ensure the optical cleanliness and sealing of the imaging lens 12. During the product testing phase, the adjustment zero point of the drive unit can be determined according to the optimal requirements of the product's optical performance, such as sharpness and virtual image distance.

[0057] When the drive unit is activated by an electrical signal, its displacement portion moves along the optical axis, causing the movable lens 121 or the movable lens group to move along the optical axis. The change in air gap alters the overall optical focal length and imaging position of the imaging lens 12, thereby achieving adjustment of the monocular virtual image distance.

[0058] It should be noted that the movable lens 121 can be a single lens or a lens group consisting of two or more lenses. When it is a lens group, the relative positions of the lenses within the group remain unchanged, and the whole is driven by the drive unit to move along the optical axis.

[0059] This example achieves the adjustment of the monocular virtual image distance by integrating the drive unit inside the imaging lens 12 to change the air gap by driving the movement of specific lenses or lens groups inside. Moreover, since the drive unit is built into the imaging lens 12, the overall structure is more compact.

[0060] In some examples of this application, the driving unit of the focusing mechanism 2 is any one of a piezoelectric ceramic driver, a voice coil motor, or a shape memory alloy driver.

[0061] All of the above-mentioned driving units can generate minute displacements under the control of electrical signals, thereby driving the display screen 11 or the movable lens 121 to move along the optical axis, achieving precise adjustment of the monocular virtual image distance.

[0062] Among them, piezoelectric ceramic actuators utilize the inverse piezoelectric effect of piezoelectric materials, which deform when a voltage is applied, thereby outputting displacement. They offer advantages such as fast response speed, high displacement accuracy, and small size. Voice coil motors achieve displacement output by controlling current, offering advantages such as large stroke, simple control, and low cost. Shape memory alloy actuators utilize the crystal structure transformation of shape memory alloy materials when heated by electricity, resulting in contraction or elongation deformation, thereby outputting displacement. They offer advantages such as small size and high driving force.

[0063] In practical applications, those skilled in the art can select the appropriate type of drive unit according to the different performance requirements of specific products, such as response speed, adjustment stroke, power consumption, and cost. This application does not limit this.

[0064] In some examples of this application, the AR optical engine module further includes an eye-tracking module and a control module (not shown in the figure). The eye-tracking module is used to track the wearer's gaze point position in real time and calculate the binocular fusion distance based on the gaze point position.

[0065] Specifically, the eye-tracking module determines the gaze point of the eyes in space by capturing the pupil position or eye movement information of the wearer's eyes, and then calculates the convergence distance from that gaze point to the wearer's eyes, i.e., the binocular convergence distance. Through the eye-tracking module, the AR optical engine module can obtain the wearer's gaze depth information in real time, providing a data basis for the subsequent setting or adjustment of the monocular virtual image distance.

[0066] In some examples of this application, the AR optical engine module further includes a control module, which is connected to the eye-tracking module and the focusing mechanism 2 respectively. The control module is used to calculate the target monocular virtual image distance based on the binocular fusion distance, control the focusing mechanism 2 to perform an adjustment action to adjust the monocular virtual image distance of the optical engine body 1 to the target monocular virtual image distance, and after adjustment, determine whether the refractive error difference between the current monocular virtual image distance and the binocular fusion distance is less than or equal to 0.25D. If not, iterative adjustment continues until the refractive error difference is less than or equal to 0.25D.

[0067] Specifically, the control module receives the binocular fusion distance output by the eye-tracking module and calculates the target monocular virtual image distance based on this binocular fusion distance. The target monocular virtual image distance refers to the monocular virtual image distance value required to ensure that the difference in refractive power between the monocular virtual image distance and the binocular fusion distance is less than or equal to 0.25D. The target monocular virtual image distance can be calculated using the formula 1 / u = 1 / v + D, where u is the binocular fusion distance, D is the lens refractive power, and v is the target monocular virtual image distance.

[0068] The control module is also used to control the focusing mechanism 2 to perform adjustment actions based on the calculated target monocular virtual image distance, so as to adjust the current monocular virtual image distance of the optical engine body 1 to the target monocular virtual image distance. After the adjustment action is completed, the control module determines whether the refractive power difference between the current monocular virtual image distance and the binocular imaging distance is less than or equal to 0.25D. If the condition is met, the current adjustment state is maintained; if the condition is not met, the control module continues to control the focusing mechanism 2 to perform iterative adjustment until the condition is met.

[0069] Through the aforementioned closed-loop adjustment mechanism, the AR optical engine module can dynamically adjust the monocular virtual image distance in real time according to the wearer's gaze point changes, ensuring that the monocular virtual image distance and the binocular image combination distance always remain matched in various usage scenarios.

[0070] In some examples of this application, the AR optical engine module also includes a temperature sensor (not shown in the figure) for detecting the temperature of the optical engine body 1.

[0071] For example, a temperature sensor can be placed on or near the optical engine body 1 to detect the temperature of the optical engine body 1 in real time. During operation, optical components such as the display screen 11 and / or imaging lens 12 will experience temperature changes due to their own heat generation or changes in ambient temperature. This causes parameters such as the refractive index and radius of curvature of the optical components to drift, which in turn causes a shift in the monocular virtual image distance, i.e., thermal defocusing. The introduction of a temperature sensor can detect the temperature of the optical engine body 1 in real time and transmit the temperature data to the control module to control the thermal defocusing of the optical engine.

[0072] In some examples of this application, the control module is also used to perform thermal defocus compensation on the target monocular virtual image distance based on the temperature of the optomechanical body 1, so as to compensate for the adjustment amount of the focusing mechanism 2.

[0073] The control module is also used to perform thermal defocus compensation on the target monocular virtual image distance based on the temperature of the optomechanical body 1. Specifically, the control module calculates the thermal drift of the monocular virtual image distance caused by temperature changes based on the temperature data detected by the temperature sensor, and adds a compensation amount when calculating the target monocular virtual image distance to offset the effect of temperature drift on the imaging position. The control module controls the drive unit of the focusing mechanism 2 to perform adjustment actions based on the compensated target monocular virtual image distance, thereby ensuring that the monocular virtual image distance can be accurately adjusted to the target value under different temperature conditions.

[0074] Through the above methods, the AR optical engine module can maintain the accuracy of monocular virtual image distance adjustment under different temperature conditions, effectively solving the thermal defocusing problem of the optical engine system and ensuring the imaging clarity and display performance of the product in various usage environments.

[0075] It is understood that the AR optical engine module used in the above embodiments and examples of this application is not limited to a specific display type. In product design, the display screen 11 of the optical engine body 1 can adopt a variety of display schemes. For example, the display screen 11 can be any one of a Micro LED display screen, an LCoS display screen, or a DLP display screen; in terms of color implementation, it can be a single full-color optical engine, a full-color optical engine composed of R / G / B three-color combination scheme, or a monochrome optical engine (such as a single green Micro LED optical engine).

[0076] The optical engines of the various display schemes described above can all be applied to the fixed-focus or variable-focus implementation schemes described in this application. Regardless of the display scheme used, the technical effect of eliminating or reducing convergence conflict can be achieved by configuring the monocular virtual image distance of the optical engine body 1 to match the binocular convergence distance of the wearer, so that the difference in refractive power between the two is less than or equal to 0.25D.

[0077] According to another embodiment of this application, a near-eye display device is provided. See also Figure 1 and Figure 7 The near-eye display device includes a left-eye optical engine module A and a right-eye optical engine module B, wherein the left-eye optical engine module A and / or the right-eye optical engine module B are AR optical engine modules as described above. The near-eye display device also includes a left-eye waveguide element C and a right-eye waveguide element D. The left-eye waveguide element C is optically coupled to the left-eye optical engine module A and is used to transmit image light to the wearer's left eye O1. The right-eye waveguide element D is optically coupled to the right-eye optical engine module B and is used to transmit image light to the wearer's right eye O2. The monocular virtual image distances of the left-eye optical engine module A and the right-eye optical engine module B are independently adjustable so that the refractive power difference between their respective monocular virtual image distances and the wearer's binocular convergence distance is less than or equal to 0.25D.

[0078] Specifically, both the left-eye optical engine module A and the right-eye optical engine module B are the aforementioned AR optical engine modules. The left-eye waveguide element C is optically coupled to the left-eye optical engine module A, used to transmit the image light emitted from the left-eye optical engine module A to the wearer's left eye O1; the right-eye waveguide element D is optically coupled to the right-eye optical engine module B, used to transmit the image light emitted from the right-eye optical engine module B to the wearer's right eye O2. The monocular virtual image distance of the left-eye optical engine module A and the right-eye optical engine module B can be controlled independently without affecting each other. Since different wearers may have different refractive powers in their left and right eyes, and the corresponding convergence parameters may also differ when the left and right eyes fixate on the same target point, the required monocular virtual image distance adjustment amount for each of the left and right eye optical engine modules may be different. The independent adjustment method for the left and right eyes allows the near-eye display device to match the binocular fusion distance for each eye separately, ensuring that the difference in refractive power between the monocular virtual image distance and the binocular fusion distance for each eye is less than or equal to 0.25D. This more accurately eliminates convergence conflict and better adapts to the individual differences of different wearers.

[0079] According to another embodiment of this application, a control method for an AR optical engine module is provided. This control method is used in the aforementioned AR optical engine module, and the control method includes: Step S1: Obtain the binocular convergence distance of the wearer; Step S2: Based on the binocular fusion distance, set the monocular virtual image distance of the optical engine body 1 in the AR optical engine module so that the difference in refractive power between the monocular virtual image distance and the binocular fusion distance is less than or equal to 0.25D; wherein, the optical engine body 1 includes an imaging lens 12 and a display screen 11.

[0080] Specifically, this control method is used to set or confirm the monocular virtual image distance of the AR optical engine module. In step S1 above, the wearer's binocular convergence distance is obtained, that is, the distance from the wearer's gaze point to the eyes. This binocular convergence distance can be obtained in real time by an eye-tracking module, or it can be directly obtained according to a preset target value of the product. In step S2, based on the obtained binocular convergence distance, the monocular virtual image distance of the optical engine body 1 in the AR optical engine module is set so that the refractive error difference between the monocular virtual image distance and the binocular convergence distance is less than or equal to 0.25D. This setting action can be, for example, fixing the monocular virtual image distance of the optical engine body 1 to a certain preset value before leaving the factory. The optical engine body 1 includes an imaging lens 12 and a display screen 11, and its monocular virtual image distance is determined by the optical relationship between the imaging lens 12 and the display screen 11.

[0081] This control method ensures that the monocular virtual image distance of the AR optical engine module matches the binocular convergence distance of the wearer, keeping the convergence distance consistent with the accommodation distance, thereby eliminating or reducing convergence conflict.

[0082] According to another embodiment of this application, a different control method for an AR optical engine module is provided. This control method is used for the aforementioned AR optical engine module, and the control method includes: Step A: Obtain the binocular convergence distance of the wearer; Step B: Determine the target monocular virtual image distance of the optical engine body 1 in the AR optical engine module based on the binocular image merging distance. The optical engine body 1 includes an imaging lens 12 and a display screen 11. Step C: Control the focusing mechanism 2 to adjust the current monocular virtual image distance of the optical engine body 1 to the target monocular virtual image distance, so that the difference in refractive power between the adjusted monocular virtual image distance and the binocular image combination distance is less than or equal to 0.25D.

[0083] Specifically, the control method is used in an AR optical engine module equipped with a focusing mechanism 2 to achieve dynamic adjustment of the monocular virtual image distance.

[0084] In step A, the binocular convergence distance of the wearer is obtained, which is the distance from the location of the wearer's gaze convergence point to the eyes. The binocular convergence distance can be obtained in real time through an eye-tracking module, or it can be set by the user through methods such as voice or manual input. The purpose of obtaining the binocular convergence distance in real time is to provide a basis for the dynamic adjustment of the subsequent monocular virtual image distance.

[0085] In step B, based on the binocular fusion distance obtained in step A, the target monocular virtual image distance that matches the binocular fusion distance is determined. The target monocular virtual image distance refers to the monocular virtual image distance value required to make the refractive error difference between the monocular virtual image distance and the binocular fusion distance less than or equal to 0.25D. Optionally, the target monocular virtual image distance can be calculated using the Gaussian imaging formula. For example, given the binocular fusion distance u and the lens refractive error D, the target monocular virtual image distance v can be calculated using the formula 1 / u = 1 / v + D.

[0086] In step C, the drive unit of the focusing mechanism 2 performs an adjustment action to adjust the current monocular virtual image distance of the optical engine body 1 to the target monocular virtual image distance determined in step B. The focusing mechanism 2 adjusts the virtual image distance by changing the relative positions of the optical elements inside the optical engine body 1. Specifically, it can move the display screen 11 along the optical axis to change the air gap between it and the imaging lens 12, or it can move the movable lens or movable lens group in the imaging lens 12 to change the air gap between it and other lenses. After the adjustment is completed, the monocular virtual image distance is updated to the target value, so that the refractive power difference between the adjusted monocular virtual image distance and the binocular convergence distance is less than or equal to 0.25D, thereby achieving the matching of the convergence distance and the adjustment distance.

[0087] This control method can dynamically adjust the monocular virtual image distance by following the changes in the binocular image merging distance of the wearer in real time, so that the monocular virtual image distance and the binocular image merging distance always match in different usage scenarios.

[0088] For example, in the two control methods of the AR optical engine module provided in this application, the method of obtaining the binocular fusion distance of the wearer includes: tracking the position of the wearer's gaze point in real time through an eye-tracking module, and calculating the binocular fusion distance based on the position of the gaze point.

[0089] Specifically, the eye-tracking module captures the center position of the wearer's pupils or the trajectory of eye movements in real time. It determines the location of the target point the wearer is focusing on in space, i.e., the fixation point, based on the principle of binocular convergence. When the wearer focuses on objects at different depths, the convergence angle of the eyes changes accordingly: it increases when focusing on near objects and decreases when focusing on distant objects. The eye-tracking module calculates the convergence angle based on the pupil position information and combines it with pre-calibrated user parameters to calculate the distance from the fixation point to the wearer's eyes; this distance is the binocular convergence distance.

[0090] Because the eye-tracking module works in real time, the binocular fusion distance can be continuously updated as the wearer's gaze point changes, providing a real-time and accurate data foundation for subsequent calculation of the target monocular virtual image distance and adjustment of the focusing mechanism.

[0091] Exemplarily, in the control method of the AR optical engine module provided in the embodiments of this application, especially in the control method of introducing a focusing mechanism, before the focusing mechanism is controlled to adjust the monocular virtual image distance of the AR optical engine module, the method further includes: Step a: Detect the temperature of the optical engine body 1 of the AR optical engine module; Step b: Calculate the thermal drift compensation amount for the monocular virtual image distance based on the temperature; Step c: Determine the target monocular virtual image distance based on the binocular image merging distance and the thermal drift compensation amount.

[0092] During operation, the optical components of the main optical engine 1, such as the display screen 11 and the imaging lens 12, experience temperature changes due to their own heat generation or variations in ambient temperature. These temperature changes cause shifts in parameters such as the refractive index and radius of curvature of the optical components, leading to a shift in the distance of the monocular virtual image, i.e., thermal defocusing. To eliminate the impact of temperature on adjustment accuracy, this application introduces a temperature compensation mechanism.

[0093] Specifically, the temperature sensor detects the temperature of the optomechanical main body 1 in real time and transmits the temperature data to the control module. Based on the current temperature data and a preset temperature-drift calibration relationship for the optomechanical main body 1, the control module calculates the thermal drift compensation amount for the monocular virtual image distance caused by temperature changes. This thermal drift compensation amount is used to offset the effect of temperature drift on the imaging position. The control module, after calculating the target monocular virtual image distance based on the binocular merging distance, adds this thermal drift compensation amount to determine the final target monocular virtual image distance, thereby ensuring that the monocular virtual image distance can be accurately adjusted to the target value under different temperature conditions, effectively solving the thermal defocusing problem of the optomechanical system.

[0094] For example, after controlling the focusing mechanism 2 to adjust the monocular virtual image distance of the AR optical engine module, the method further includes: Determine whether the current adjustment state meets the condition that the refractive error difference is less than or equal to 0.25D; If the condition is not met, the adjustment amount of the focusing mechanism 2 is iteratively optimized until the condition is met.

[0095] After the focusing mechanism 2 performs the adjustment action, the actual adjustment result of the monocular virtual image distance may have a certain deviation. To eliminate the impact of this deviation on the adjustment accuracy, this application introduces an iterative optimization mechanism.

[0096] Specifically, after the focusing mechanism 2 completes one adjustment action, the control module obtains the current monocular virtual image distance and binocular convergence distance, and determines whether the refractive error difference between the two meets the condition of being less than or equal to 0.25D. If the condition is met, the adjustment is completed, and the current adjustment state is maintained; if the condition is not met, the control module redetermines the target monocular virtual image distance based on the current deviation, and controls the focusing mechanism 2 to perform the adjustment action again, iterating repeatedly until the condition is met. Through the above iterative optimization method, it is possible to ensure that the refractive error difference between the monocular virtual image distance and the binocular convergence distance is always controlled within 0.25D, ensuring adjustment accuracy.

[0097] The control method (including the focusing mechanism 2) described above in this application will be illustrated by specific embodiments below.

[0098] In one specific embodiment of this application, see [link to relevant documentation]. Figure 8 The control method for the AR optical engine module includes the following steps: Step S1: Obtain the binocular convergence distance of the wearer.

[0099] The eye-tracking module captures the pupil position of the wearer's eyes in real time, determines the fixation point of the eyes in space, and calculates the convergence distance from the fixation point to the wearer's eyes, which is the binocular convergence distance.

[0100] Step S2: Detect the temperature of the optical engine body 1 of the AR optical engine module.

[0101] The temperature of the main body 1 of the optomechanical system is detected in real time by a temperature sensor, and the temperature data is transmitted to the control module.

[0102] Step S3: Determine the target monocular virtual image distance based on the binocular image merging distance and temperature.

[0103] The control module calculates the desired monocular virtual image distance based on the binocular fusion distance using the formula 1 / u = 1 / v + D, where u is the binocular fusion distance, D is the lens diopter, and v is the monocular virtual image distance. Simultaneously, the control module calculates the thermal drift compensation amount based on the temperature of the optomechanical unit 1 and a preset temperature-drift calibration relationship. The calculated desired monocular virtual image distance is then superimposed with the thermal drift compensation amount to determine the target monocular virtual image distance.

[0104] Step S4: Control the focusing mechanism to adjust the monocular virtual image distance of the AR optical engine module to the target monocular virtual image distance.

[0105] The control module controls the focusing mechanism to perform adjustment actions. The drive unit generates displacement under the control of electrical signals, driving the display screen to move along the optical axis to change the gap between the display screen and the imaging lens, or driving the movable lens or movable lens group in the imaging lens to move along the optical axis to change the interval between it and other lenses, thereby adjusting the current monocular virtual image distance to the target monocular virtual image distance.

[0106] Step S5: Determine whether the current adjustment state meets the condition that the refractive error difference is less than or equal to 0.25D. If it does, proceed to step S6; otherwise, return to step S4 above and iteratively optimize the adjustment amount of the focusing mechanism until the condition is met.

[0107] After the focusing mechanism completes one adjustment action, the control module determines whether the difference in refractive power between the current monocular virtual image distance and the binocular image combination distance is less than or equal to 0.25D. If it meets the condition, step S6 is executed; otherwise, the process returns to step S4 to iteratively optimize the adjustment amount of the focusing mechanism until the condition is met.

[0108] Step S6: Maintain the current adjustment state and monitor it periodically.

[0109] The control module maintains the current adjustment state of the focusing mechanism, ensuring that the difference in refractive power between the monocular virtual image distance and the binocular fusion distance remains less than or equal to 0.25D. The eye-tracking module continues to track the wearer's gaze point position in real time, and the temperature sensor continues to monitor the temperature of the optical engine body 1 in real time. When the binocular fusion distance or temperature changes, steps S1 to S6 are re-executed.

[0110] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0111] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. An AR optical engine module, characterized in that, It includes an optical engine body (1), which includes an imaging lens (12) and a display screen (11). The optical engine body (1) is configured to set its monocular virtual image distance according to the binocular fusion distance of the wearer, so that the difference in refractive power between the monocular virtual image distance and the binocular fusion distance is less than or equal to 0.25D.

2. The AR optical engine module according to claim 1, characterized in that, The AR optical engine module also includes a focusing mechanism (2), which is connected to the optical engine body (1). The focusing mechanism is used to adjust the monocular virtual image distance of the optical engine body (1) according to the binocular image merging distance of the wearer, so that the difference in refractive power between the monocular virtual image distance and the binocular image merging distance is less than or equal to 0.25D.

3. The AR optical engine module according to claim 2, characterized in that, The matching relationship between the binocular image distance and the monocular virtual image distance satisfies the following formula: 1 / u = 1 / v + D, where u is the binocular image distance of the wearer, v is the monocular virtual image distance of the optical engine, and D is the lens diopter.

4. The AR optical engine module according to claim 1, characterized in that, The focusing mechanism (2) includes a driving unit, which is disposed between the display screen (11) and the imaging lens (12) and is used to drive the display screen (11) to change its relative position with the imaging lens (12) along the optical axis.

5. The AR optical engine module according to claim 1, characterized in that, The imaging lens (12) includes at least one movable lens (121) or at least one group of movable lenses. The focusing mechanism (2) includes a driving unit connected to the movable lens or the group of movable lenses, for driving the movable lens or the group of movable lenses to move along the optical axis to change the air gap between the movable lens or the group of movable lenses and other lenses in the imaging lens.

6. The AR optical engine module according to claim 4 or 5, characterized in that, The driving unit is any one of a piezoelectric ceramic driver, a voice coil motor, or a shape memory alloy driver.

7. The AR optical engine module according to claim 2, characterized in that, The AR optical engine module also includes an eye-tracking module, which is used to track the wearer's gaze point position in real time and calculate the binocular fusion distance based on the gaze point position.

8. The AR optical engine module according to claim 7, characterized in that, The AR optical engine module also includes a control module, which is connected to the eye-tracking module and the focusing mechanism (2) respectively. The control module is used to calculate the target monocular virtual image distance based on the binocular fusion distance, control the focusing mechanism (2) to perform adjustment actions to adjust the monocular virtual image distance of the optical engine body (1) to the target monocular virtual image distance, and after adjustment, determine whether the refractive error difference between the current monocular virtual image distance and the binocular fusion distance is less than or equal to 0.25D. If not, continue iterative adjustment until the refractive error difference is less than or equal to 0.25D.

9. The AR optical engine module according to claim 8, characterized in that, The AR optical engine module also includes a temperature sensor for detecting the temperature of the optical engine body (1).

10. The AR optical engine module according to claim 9, characterized in that, The control module is also used to perform thermal defocus compensation on the target monocular virtual image distance based on the temperature of the optical engine body (1), and to control the focusing mechanism (2) to perform adjustment actions based on the compensated target monocular virtual image distance.

11. A near-eye display device, characterized in that, include: A left-eye optical engine module and a right-eye optical engine module, wherein the left-eye optical engine module and / or the right-eye optical engine module are AR optical engine modules as described in any one of claims 1-10; A left-eye optical waveguide element and a right-eye optical waveguide element, wherein the left-eye optical waveguide element is optically coupled to the left-eye optical engine module and is used to transmit image light to the wearer's left eye (01), and the right-eye optical waveguide element is optically coupled to the right-eye optical engine module and is used to transmit image light to the wearer's right eye (02). The monocular virtual image distances of the left and right optical imaging modules are adjusted independently so that the difference in refractive power between their respective monocular virtual image distances and the binocular fusion distance of the wearer is less than or equal to 0.25D.

12. A control method for an AR optical engine module, characterized in that, include: Obtain the binocular convergence distance of the wearer; Based on the binocular fusion distance, the monocular virtual image distance of the optical engine body (1) in the AR optical engine module is set so that the difference in refractive power between the monocular virtual image distance and the binocular fusion distance is less than or equal to 0.25D; wherein, the optical engine body (1) includes an imaging lens (12) and a display screen (11).

13. A control method for an AR optomechanical module, characterized in that, include: Obtain the binocular convergence distance of the wearer; Based on the binocular image merging distance, the target monocular virtual image distance of the optical engine body (1) in the AR optical engine module is determined. The optical engine body (1) includes an imaging lens (12) and a display screen (11). The focusing mechanism (2) adjusts the current monocular virtual image distance of the optical engine body (1) to the target monocular virtual image distance so that the difference in refractive power between the adjusted monocular virtual image distance and the binocular image combination distance is less than or equal to 0.25D.

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