Projector for AR optical waveguide test
By designing a projector for AR optical waveguide testing, the problem that existing projectors cannot provide near-diffraction-limited optical quality has been solved, enabling high-brightness, high-uniformity, and high-definition optical waveguide testing, thereby improving R&D and mass production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- OPTOFIDELITY TECH (ZHUHAI) CO LTD
- Filing Date
- 2026-02-10
- Publication Date
- 2026-05-12
AI Technical Summary
Existing projectors cannot provide optical quality close to the diffraction limit, cannot accurately measure the true performance of AR optical waveguides, and lack reference equipment suitable for testing optical waveguides.
Design a projector for AR optical waveguide testing, including a light source module, a focusing module, a pattern module, and a projection lens. The light source module provides light that meets preset requirements, the focusing module converts the light into a preset aperture and numerical aperture, the pattern module provides a projection pattern, and the projection lens converts the image into outgoing light at different angles and converges it to the exit pupil position to form a test light with high brightness, high definition, high uniformity, high contrast, and a large field of view.
It achieves near-diffraction-limited image quality, provides efficient optical waveguide testing methods, and improves R&D and mass production efficiency.
Smart Images
Figure CN122016249A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of optical instrument technology, and in particular to a projector for AR optical waveguide testing. Background Technology
[0002] Augmented reality display technology is developing rapidly, but it also faces many technical challenges in research and development and production. Among these challenges, the testing of optical waveguide lenses is particularly critical. Currently, the industry lacks a projector that can serve as a reference for testing optical waveguides. Therefore, it is impossible to accurately measure the true performance of optical waveguides. Such a projector needs optical quality close to the diffraction limit, which consumer projectors cannot meet. Summary of the Invention
[0003] In view of this, the purpose of this invention is to provide a projector for AR optical waveguide testing that can provide image quality close to the diffraction limit.
[0004] On one hand, embodiments of the present invention provide a projector for AR optical waveguide testing, including a light source module, a focusing module, a map module, and a projection lens, wherein... The light source module is used to provide light that meets preset requirements; The focusing module is used to convert the light emitted by the light source module into light with a preset aperture and a preset numerical aperture. The image card module is used to provide a preset projection pattern; The projection lens is used to convert the image of the projected pattern into outgoing light at different angles, and to converge the outgoing light at all angles to the exit pupil position.
[0005] Optionally, the light source module includes a plurality of first light sources, a multi-branch fiber bundle, and a first aperture, wherein the light emitted by the plurality of first light sources is coupled through the multi-branch fiber bundle and transmitted to the first aperture.
[0006] Optionally, the focusing module includes a first cemented lens and a second cemented lens.
[0007] Optionally, the projection lens includes a first meniscus lens, a second meniscus lens, a third meniscus lens, a fourth meniscus lens, a fifth meniscus lens, a first biconcave lens, and a first biconvex lens.
[0008] Optionally, the total length of the projection lens is less than 240mm, and the diameter of the largest lens in the projection lens is less than 70mm.
[0009] Optionally, the light source module includes a plurality of second light sources, an integrating sphere, and a second aperture. The second aperture is disposed at the light outlet of the integrating sphere. The light emitted by the plurality of second light sources converges at the integrating sphere and then passes through the light outlet to reach the second aperture.
[0010] Optionally, the projection lens includes a prism, a first plano-convex lens, a second plano-convex lens, a third plano-convex lens, a second biconcave lens, a plano-concave lens, a sixth meniscus lens, a seventh meniscus lens, a second biconvex lens, a third biconvex lens, a third cemented lens, an eighth meniscus lens, and a fourth biconvex lens.
[0011] Optionally, the total length of the projection lens is less than 390mm, and the diameter of the largest lens in the projection lens is less than 51mm.
[0012] Optionally, the exit pupil diameter of the projection lens is in the range of 1~5mm.
[0013] Optionally, the projector further includes a polarizer and / or a neutral density filter, which is disposed between the focusing module and the card module or between the card module and the projection lens.
[0014] Implementing the embodiments of the present invention has the following beneficial effects: The projector used for AR optical waveguide testing in this embodiment includes a light source module, a focusing module, a pattern module, and a projection lens. The light emitted by the light source module is converted into light with a preset aperture and a preset numerical aperture by the focusing module, and then passes through the projection pattern provided by the pattern module. The projection lens converts the image of the projection pattern into outgoing light at different angles and converges the outgoing light at all angles to the exit pupil position, thereby forming a test light with high brightness, high definition, high uniformity, high contrast, and a large field of view, providing image quality close to the diffraction limit. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of an optical waveguide testing system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a projector for AR optical waveguide testing provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of another projector for AR optical waveguide testing provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a focusing module and a projection lens provided in an embodiment of the present invention; Figure 5 This is the modulus of the optical transfer function of a projector used for AR optical waveguide testing, as provided in an embodiment of the present invention; Figure 6This is a schematic diagram of another projector for AR optical waveguide testing provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of a light source module provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of another light-gathering module and projection lens provided in an embodiment of the present invention; Figure 9 This is the modulus of the optical transfer function of another projector used for AR optical waveguide testing, provided in an embodiment of the present invention. Detailed Implementation
[0016] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The step numbers in the following embodiments are only for ease of explanation and do not limit the order of the steps. The execution order of each step in the embodiments can be adapted according to the understanding of those skilled in the art.
[0017] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., used in the specification, claims, and the foregoing drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatuses.
[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.
[0019] Optical waveguide testing system such as Figure 1As shown, A1 represents an AR projection instrument, A2 represents an optical waveguide, and A3 represents a testing instrument. A1 projects light of different colors and patterns. The light enters the AR optical waveguide of A2, is transmitted within the waveguide, and is then output. A3 receives the light and analyzes the transmission performance of A2. A1 and A3 can be used for pre-testing benchmarks to avoid the influence of system errors on the test. Furthermore, the quality of the instruments A1 and A3 determines the overall quality of the system. This invention relates to a projector for testing AR optical waveguides.
[0020] See Figure 2 This invention provides a projector for AR optical waveguide testing, comprising a light source module 1, a focusing module 2, a map module 3, and a projection lens 4. Light source module 1 is used to provide light that meets preset requirements; Concentrating module 2 is used to convert the light emitted by the light source module into light with a preset aperture and a preset numerical aperture. Graphic module 3 is used to provide preset projection patterns; Projection lens 4 is used to convert the image of the projected pattern into outgoing light at different angles and to converge the outgoing light at all angles to the exit pupil position.
[0021] Specifically, the light source module includes, but is not limited to, a light source (such as an LED, broadband light source, laser, etc.), a heat dissipation device, a power supply, a control circuit, a coupling device (such as an integrating sphere, optical fiber, repeater, etc.), and a light output aperture. The light source can be selected from any wavelength and can output monochromatic or multi-color mixed light, featuring high brightness and high uniformity.
[0022] Specifically, the focusing module consists of several spherical or aspherical lenses. Using fewer lenses, it transforms a small-aperture, large-NA (numerical aperture) light source into a large-aperture, smaller-NA light source, while minimizing chromatic aberration caused by transmission and maintaining the uniformity of the light source. Therefore, some diffusers can be added here to further improve the uniformity of the light source.
[0023] Specifically, the chart module consists of several reticles, motion axes, alignment devices, and a control system; this module enables the switching of different test charts, that is, the projected pattern is controlled by this module.
[0024] Specifically, the projection lens converts the images of different spatial positions on the card into light rays emitted at different angles, directs and converges all the light rays from all angles to the exit pupil position, and then diverges them. The projection lens projects the light rays from each angle into a smaller area, and the lens needs certain adjustment functions, including but not limited to focusing, adjusting the size of the exit pupil area, and adjusting the polarization angle.
[0025] Optionally, the light source module includes several first light sources, a multi-branch fiber bundle, and a first aperture. The light emitted by the several first light sources is coupled through the multi-branch fiber bundle and transmitted to the first aperture.
[0026] It should be noted that the number of first light sources is determined based on the actual application, and this embodiment does not impose a specific limitation. The number of branches in the fiber bundle is determined based on the number of first light sources.
[0027] Optionally, the focusing module includes a first cemented lens and a second cemented lens.
[0028] It should be noted that the specific structures of the first and second cemented lenses are determined based on actual applications, and this embodiment does not impose specific limitations. In a specific embodiment, see [reference needed]. Figure 3 Both the first and second cemented lenses are cemented together from a plano-concave lens and a biconvex lens. The image plane diameter of the focusing module ranges from 60 to 80 mm, the image telecentricity is <0.5°, the output diameter is <4 mm, and the root mean square radius (RMS radius) is <50 μm.
[0029] Optionally, the projection lens includes a first meniscus lens, a second meniscus lens, a third meniscus lens, a fourth meniscus lens, a fifth meniscus lens, a first biconcave lens, and a first biconvex lens.
[0030] In one specific embodiment, see Figure 3 The light source module 101 consists of multiple LEDs and heat dissipation devices (A1 / A2 / A3), glass optical fiber A4 and aperture A5, which converge and guide light of different colors to A5.
[0031] The focusing module 102 consists of two achromatic cemented lenses, each with a focal length ranging from 65 to 85 mm, which diffuse and converge the light at A5 to A6.
[0032] The image card module 103 consists of several reticles or glass image cards, and can be equipped with a moving device for switching image cards. The image cards can be equipped with some adjustment devices to finely adjust their axis and tilt angle, so that they can be aligned with the optical axis of the projection lens.
[0033] The projection lens 104 is designed as an f-theta scanning objective, but it is used in the opposite way here. Light passes through A6 and enters the lens through L07, eventually converging at A7. A7 is the exit pupil, and the diameter of the exit pupil of A7 can be changed by adjusting the size of the aperture at A5. The diameter of A7 is usually 1~5mm. Among them, the lenses L01 / L02 / L03 / L04 / L05 are meniscus lenses, L06 is a biconcave lens, and L07 is a biconvex lens.
[0034] The A4 multi-branch glass fiber bundle can be split into multiple branches; in this example, it is split into three branches, connecting to the red LED, green LED, and blue LED respectively. Light can be guided to A5 individually or in combination through A4, achieving efficient transmission.
[0035] A5 represents the aperture stop. Since the projection lens 104 does not have an internal aperture stop, it needs to be adjusted by the aperture stops of other parts of the system to adjust the relative aperture, thereby indirectly changing the size of the exit pupil at A7.
[0036] A6 represents a test chart, typically using high-purity quartz glass as the substrate. Its core light-shielding layer is a thin film of metallic chromium (Cr), resulting in very high contrast. Light passes through the uncoated areas, forming the test pattern.
[0037] A7 is the exit pupil position of the system, but for a lens, 104 is the entrance pupil position. The diameter of the A7 exit pupil is determined by the size of the aperture stop at A5, and its diameter is usually the same as the diameter of the waveguide coupling area.
[0038] The working principle is as follows: Light sources A1, A2, and A3 are converged to point A5 via a glass fiber bundle A4. Since AR waveguide projectors require very high brightness, fiber optics are used to maximize the coupling light efficiency. Simultaneously, the glass fiber bundle can be selected within a diameter range of tens of micrometers to tens of millimeters, and can easily combine multiple beams of different colors into a uniformly emitted beam. The beam size is controlled via A5. The light is converged at surface 103 via 102, and the light passing through the pattern card exits at A7 via 104, forming the exit pupil. The exit pupil surface typically needs to match the coupling area of the waveguide to ensure that light from all viewing angles (i.e., different pattern positions on the pattern card) can enter the waveguide. This scheme can achieve the requirements of high brightness, high contrast, high definition, and high uniformity, and can serve as a projection optical engine for waveguide benchmark testing.
[0039] Optionally, the A7 can be fitted with a solid aperture, with a diameter of 1 to 5 mm.
[0040] Optionally, polarizers and neutral density filters can be added before and after A6 of 103 to meet certain specific testing requirements.
[0041] Optionally, a high-precision outer surface reflector can be added between L01 and A7 to reduce physical interference between the mirror tube and other components. The reflection angle can be adjusted according to the actual situation.
[0042] Optionally, the distance between A6 and L07 can be adjusted to meet different projection virtual image distances, typically ranging from 250mm to infinity.
[0043] Optionally, the total length of the projection lens is less than 240mm, and the diameter of the largest lens in the projection lens is less than 70mm.
[0044] Specifically, the total length of the projection lens and the diameter of the largest lens in the projection lens are determined according to the actual application, and this embodiment does not impose specific limitations. In addition, the focal length of the projection lens is 80-120mm, the focusing range is 250mm to infinity, the applicable spectrum is 350~780 nm, the image telecentricity is <1°, and the image plane diameter range is 50-80mm.
[0045] In one specific embodiment, parameters Figure 4 The specific design parameters for the projection lens and the focusing module are as follows:
[0046] Image quality of the projection lens, such as Figure 5 As shown, it is very close to the diffraction limit and has good image quality.
[0047] Optionally, the light source module includes several second light sources, an integrating sphere, and a second aperture. The second aperture is located at the light outlet of the integrating sphere. The light emitted by the several second light sources converges at the integrating sphere and then passes through the light outlet to reach the second aperture.
[0048] It should be noted that the number of second light sources is determined based on the actual application, and this embodiment does not impose specific limitations.
[0049] In one specific embodiment, see Figure 6 and Figure 7 The light source module 201 includes multiple LEDs and heat dissipation devices (B11 / B12 / B13), a small integrating sphere B2, a light outlet B3, and an aperture B4.
[0050] Optionally, the projection lens includes a prism, a first plano-convex lens, a second plano-convex lens, a third plano-convex lens, a second biconcave lens, a plano-concave lens, a sixth meniscus lens, a seventh meniscus lens, a second biconcave lens, a third biconcave lens, a third cemented lens, an eighth meniscus lens, and a fourth biconcave lens.
[0051] In one specific embodiment, see Figure 6 The focusing module 202 consists of two achromatic cemented lenses, each with a focal length range of 60-85mm, which diffuse and converge the light at B4 to B5. The focusing module has an image plane diameter of 26.3mm, an image-side telecentricity of <0.5°, an output diameter range of 7-11mm, and a root mean square radius (RMS radius) of <110μm.
[0052] The drawing module 203 consists of several reticles or glass drawing cards and can be equipped with a moving device for switching drawing cards.
[0053] Projection lens 204 is a conical lens design, but used in reverse here. Light passes through B5, enters the lens via L13, and finally converges at B7. B7 is the exit pupil, and its diameter can be changed by adjusting the size of the aperture stop at B6. Typically, the diameter of B7 is 1-5mm. L01 is a prism, which can be designed as a prism. L02 / L03 / L04 are plano-convex lenses, L05 is a biconcave lens, L06 is a plano-concave lens, L07 / L08 / L12 are meniscus lenses, L09 / L10 / L13 are biconvex lenses, and L11 is a cemented lens.
[0054] Optionally, the total length of the projection lens is less than 390mm, and the diameter of the largest lens in the projection lens is less than 51mm.
[0055] It should be noted that the total length of the projection lens and the diameter of the largest lens in the projection lens are determined according to the actual application, and this embodiment does not impose specific limitations. In addition, the light-transmitting aperture of the projection lens ranges from 1 to 5 mm, the focal length ranges from -16 to -18.5 mm, the focusing range is 250 mm to infinity, the applicable spectral range is 350 to 780 nm, the image telecentrism is <0.8°, and the image plane diameter is 24 mm.
[0056] Optionally, the projection lens 204 includes a conical lens designed to be telecentric on the image side, which can reduce the B5 size and improve system uniformity.
[0057] Optionally, B6 is designed as an internal aperture stop, allowing stepless adjustment of the exit pupil diameter at B7.
[0058] Optionally, the B7 can be fitted with a solid aperture, the diameter of which can be 1~5mm.
[0059] Optionally, polarizers and neutral density filters can be added before and after B5 of 203 to meet certain specific testing requirements.
[0060] Optionally, at L01, a total internal reflection prism can be designed. The prism can change the angle of the incident optics by internal reflection, thereby changing the angle of the overall lens at the rear end. The reflection angle can be adjusted according to the actual situation.
[0061] Optionally, the distance between B5 and L13 can be adjusted to meet different projection virtual image distances, typically ranging from 250mm to infinity.
[0062] Optionally, the diagram at B5 can be pre-distorted in advance based on the distortion of the 204 projection lens to offset the distortion effect caused by the 204 projection lens.
[0063] Optionally, L13 can be finely adjusted forward and backward to meet different projection virtual image distances, typically ranging from 250mm to infinity.
[0064] Optionally, B2 may include multiple light source apertures to provide mounting positions for the B1 light source. The mounted light source can be a coherent light source or an incoherent light source. In this case, a scheme using red LEDs, green LEDs, and blue LEDs is selected.
[0065] In one specific embodiment, see Figure 8 The lens components shown, including projection lens 204 and focusing lens 202, are designed as follows:
[0066] The MTF curve of the projection lens is as follows Figure 9 As shown, its full-field image quality is very good, approaching the diffraction limit.
[0067] Implementing this embodiment of the invention provides the following beneficial effects: The projector used for AR waveguide testing in this embodiment includes a light source module, a focusing module, a pattern module, and a projection lens. The light emitted by the light source module is converted into light with a preset aperture and a preset numerical aperture by the focusing module, and then passes through the projection pattern provided by the pattern module. The projection lens converts the image of the projection pattern into outgoing light at different angles and converges all outgoing light at the exit pupil position, thereby forming a test beam with high brightness, high definition, high uniformity, high contrast, and a large field of view, providing image quality close to the diffraction limit. This solves the problem of lacking a standard optical-mechanical reference test encountered in R&D and mass production, and helps to improve R&D and mass production efficiency.
[0068] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.
[0069] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.
Claims
1. A projector for AR optical waveguide testing, characterized in that, It includes a light source module, a focusing module, a graphics card module, and a projection lens, among which, The light source module is used to provide light that meets preset requirements; The focusing module is used to convert the light emitted by the light source module into light with a preset aperture and a preset numerical aperture. The image card module is used to provide a preset projection pattern; The projection lens is used to convert the image of the projected pattern into outgoing light at different angles, and to converge the outgoing light at all angles to the exit pupil position.
2. The projector for AR optical waveguide testing according to claim 1, characterized in that, The light source module includes several first light sources, a multi-branch fiber bundle, and a first aperture. The light emitted by the several first light sources is coupled through the multi-branch fiber bundle and transmitted to the first aperture.
3. The projector for AR optical waveguide testing according to claim 1, characterized in that, The focusing module includes a first cemented lens and a second cemented lens.
4. The projector for AR optical waveguide testing according to claim 2, characterized in that, The projection lens includes a first meniscus lens, a second meniscus lens, a third meniscus lens, a fourth meniscus lens, a fifth meniscus lens, a first biconcave lens, and a first biconvex lens.
5. The projector for AR optical waveguide testing according to claim 4, characterized in that, The total length of the projection lens is less than 240mm, and the diameter of the largest lens in the projection lens is less than 70mm.
6. The projector for AR optical waveguide testing according to claim 1, characterized in that, The light source module includes several second light sources, an integrating sphere, and a second aperture. The second aperture is disposed at the light outlet of the integrating sphere. The light emitted by the several second light sources converges at the integrating sphere and then passes through the light outlet to reach the second aperture.
7. The projector for AR optical waveguide testing according to claim 6, characterized in that, The projection lens includes a prism, a first plano-convex lens, a second plano-convex lens, a third plano-convex lens, a second biconcave lens, a plano-concave lens, a sixth meniscus lens, a seventh meniscus lens, a second biconcave lens, a third biconcave lens, a third cemented lens, an eighth meniscus lens, and a fourth biconcave lens.
8. The projector for AR optical waveguide testing according to claim 7, characterized in that, The total length of the projection lens is less than 390mm, and the diameter of the largest lens in the projection lens is less than 51mm.
9. The projector for AR optical waveguide testing according to any one of claims 1-8, characterized in that, The exit pupil diameter of the projection lens ranges from 1 to 5 mm.
10. The projector for AR optical waveguide testing according to any one of claims 1-8, characterized in that, The projector also includes a polarizer and / or a neutral density filter, which is disposed between the focusing module and the card module or between the card module and the projection lens.