Optical module and near-eye display device
By introducing an optical module design that incorporates a waveguide substrate, a coupling grating, and a collimating element into a near-eye display device, the problem of the large size occupied by the optical engine is solved, and the miniaturization and aberration optimization of the device are achieved.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ZHUHAI MOJIE TECH CO LTD
- Filing Date
- 2025-06-16
- Publication Date
- 2026-07-09
AI Technical Summary
In existing near-eye display devices, the light engine occupies a large volume, making it difficult to achieve a thinner and lighter design.
An optical module design employing a waveguide substrate, a coupling grating, first and second collimating elements, and a coupling grating optimizes aberrations and shortens the distance between the optical engine and the waveguide substrate by collimating the beam and folding the optical path within the optical module.
This design enables miniaturization of near-eye display devices, improves the efficiency of the beam propagation path, optimizes aberrations, and reduces the overall size of the device.
Smart Images
Figure CN2025101218_09072026_PF_FP_ABST
Abstract
Description
Optical modules and near-eye display devices
[0001] This application claims priority to Chinese Patent Application No. 2024119984769, filed with the Chinese Patent Office on December 31, 2024, entitled "Optical Module and Near-Eye Display Device", the entire contents of which are incorporated herein by reference. Technical Field
[0002] This application relates to the field of display technology, and in particular to an optical module and a near-eye display device. Background Technology
[0003] Near-eye display devices typically consist of two parts: a light engine and a waveguide. The light engine includes a display screen and an optical engine module, located between the display screen and the waveguide. The optical engine module collimates the light emitted from the display screen into parallel rays and directs them towards the waveguide. Furthermore, to facilitate the correction of aberrations in the image formed by the light in the human eye and improve image quality, a certain number of glass-plastic hybrid lens groups are usually required. These lens groups typically have air gaps between them. Therefore, the light emitted from the display screen has a certain transmission length when it reaches the coupling grating, i.e., the total system length. This results in the light engine occupying a certain volume in the near-eye display device, making it difficult to achieve a thinner and lighter near-eye display. Summary of the Invention
[0004] This application provides an optical module and a near-eye display device, aiming to reduce the size of the near-eye display device.
[0005] In a first aspect, embodiments of this application provide an optical module, including:
[0006] Waveguide substrate;
[0007] A coupling grating is disposed on one side of the waveguide substrate;
[0008] The first collimating element is disposed on the side of the waveguide substrate away from the coupling grating, or on the side of the coupling grating away from the waveguide substrate.
[0009] The second collimating element is disposed on the side of the first collimating element that is away from the waveguide substrate;
[0010] A coupling grating is disposed on the waveguide substrate;
[0011] The light beam can pass through the waveguide substrate and be transmitted to the first collimating element. The light beam emitted from the first collimating element is reflected by the second collimating element. The light beam emitted from the second collimating element is transmitted to the first collimating element and then coupled into the waveguide substrate via the coupling grating and transmitted within the waveguide substrate. It is then coupled out via the coupling grating. The first collimating element and the second collimating element are used to collimate the light beam.
[0012] Optionally, both the first collimating element and the second collimating element include a polarizing element, and the coupled grating is a polarizing grating.
[0013] Optionally, the polarizing element includes a liquid crystal polarizing lens.
[0014] Optionally, the first collimating element may be one or more;
[0015] When there are multiple first collimating elements, the multiple first collimating elements are arranged sequentially along the direction from the waveguide substrate to the second collimating element.
[0016] Optionally, the coupled grating is a non-polarizing grating or a polarizing grating.
[0017] Optionally, all of the plurality of coupled-out gratings are polarization gratings;
[0018] The light beam is coupled out through a plurality of said coupling gratings and transmitted along a transmission direction, or the plurality of said coupling gratings can expand the pupil of the light beam to form at least two light beams with different transmission directions.
[0019] Optionally, the optical module also includes:
[0020] A protective element is disposed on the side of the waveguide substrate facing the first collimating element.
[0021] Optionally, the protective element is disposed between the first collimating element and the waveguide substrate, or the protective element is disposed between the first collimating element and the second collimating element.
[0022] Optionally, an optical adhesive layer is provided between the protective element and the waveguide substrate to enable the light beam to be transmitted within the waveguide substrate and the protective element after being coupled into the waveguide substrate via the coupling grating.
[0023] Secondly, embodiments of this application also provide a near-eye display device, including the optical module described in the first aspect.
[0024] This application provides an optical module and a near-eye display device. When the optical module of this application is applied to the near-eye display device, the light beam emitted from the image source can be collimated by a first collimating element and a second collimating element before being coupled into the waveguide substrate, so that the light beam can be coupled into the waveguide substrate in parallel for efficient transmission within the waveguide substrate. By adjusting the light beam through the first collimating element and the second collimating element, the beam propagation path can be increased and aberrations can be optimized. Furthermore, by folding the optical path, the distance between the image source and the waveguide substrate of the near-eye display device can be effectively shortened, reducing the size of the near-eye display device and achieving a miniaturized design. Attached Figure Description
[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0026] Figure 1 is a schematic diagram of the structure of a near-eye display device provided in an embodiment of this application;
[0027] Figure 2 shows the propagation path of the light beam at different viewing angles in the near-eye display device in Figure 1;
[0028] Figure 3 is a schematic diagram of another near-eye display device provided in an embodiment of this application;
[0029] Figure 4 is a structural schematic diagram of another near-eye display device provided in an embodiment of this application;
[0030] Figure 5 is a K-vector diagram of the optical waveguide when there are two coupling gratings provided in the embodiment of this application.
[0031] Key reference numerals: 100, optical module; 10, waveguide substrate; 20, coupling grating; 30, first collimating element; 40, second collimating element; 50, coupling grating; 60, polarization modulator; 70, protective element; 80, optical adhesive layer; 200, near-eye display device; 210, image source. Detailed Implementation
[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0033] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.
[0034] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.
[0035] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0036] Please refer to Figures 1 and 2. Figure 1 shows an optical module 100 provided in an embodiment of this application. The optical module 100 includes a waveguide substrate 10, a coupling grating 20, a first collimating element 30, a second collimating element 40, and a coupling grating 50. The coupling grating 20 is disposed on one side of the waveguide substrate 10. The first collimating element 30 is disposed on the side of the waveguide substrate 10 opposite to the coupling grating 20, or on the side of the coupling grating 20 opposite to the waveguide substrate 10. The second collimating element 40 is disposed on the side of the first collimating element 30 opposite to the waveguide substrate 10. The coupling grating 50 is disposed on the waveguide substrate 10. The light beam can pass through the waveguide substrate 10 and be transmitted to the first collimating element 30. The light beam exiting the first collimating element 30 is reflected by the second collimating element 40. The light beam exiting the second collimating element 40 is transmitted back to the first collimating element 30, coupled into the waveguide substrate 10 via the coupling grating 20, and propagates within the waveguide substrate 10. It is then coupled out via the coupling grating 50. The first collimating element 30 and the second collimating element 40 are used to collimate and correct aberrations in the light beam.
[0037] As can be understood, as shown in Figure 1, when the optical module 100 is applied to the near-eye display device 200, the light beam emitted by the image source 210 can be collimated by the first collimating element 30 and the second collimating element 40 before being coupled into the waveguide substrate 10, so that the light beam can be coupled into the waveguide substrate 10 in parallel for efficient transmission within the waveguide substrate 10. Furthermore, by adjusting the light beam through the first collimating element 30 and the second collimating element 40, the beam propagation path can be increased and aberrations can be optimized. Moreover, by folding the optical path, the distance between the image source 210 and the waveguide substrate 10 of the near-eye display device 200 can be effectively shortened, reducing the size of the near-eye display device 200 and achieving a miniaturized design of the near-eye display device 200.
[0038] For example, the waveguide substrate 10 may be made of glass or resin.
[0039] For example, the coupled-in grating 20 may be a transmissive grating or a reflective grating, and the coupled-out grating 50 may be a transmissive grating or a reflective grating.
[0040] As shown in Figure 1, in some embodiments, the light beam can pass through the waveguide substrate 10 and the coupling grating 20 and then be transmitted to the first collimating element 30. After exiting the first collimating element 30, it is reflected by the second collimating element 40, passes through the first collimating element 30 again, and then exits to the coupling grating 20. The coupling grating 20 couples the light beam into the waveguide substrate 10. This facilitates the light beam being reflected from the second collimating element 40 and transmitted to the coupling grating 20 at a suitable angle after passing through the first collimating element 30, thus improving the coupling efficiency.
[0041] In some embodiments, the coupling grating 20, the first collimating element 30, and the second collimating element 40 are correspondingly arranged in the direction from the waveguide substrate 10 to the second collimating element 40, so that the light beam emitted by the image source 210 can pass through the waveguide substrate 10 and the coupling grating 20 and be transmitted to the first collimating element 30. After exiting the first collimating element 30, the light beam is reflected by the second collimating element 40 and then passes through the first collimating element 30 again before exiting to the coupling grating 20. The coupling grating 20 couples the light beam into the waveguide substrate 10.
[0042] For example, the direction from the waveguide substrate 10 to the second collimating element 40 can be shown as the Z0-Z1 direction in Figure 1.
[0043] In some embodiments, both the first collimating element 30 and the second collimating element 40 include polarizing elements, and the coupling grating 20 includes a polarizing grating. It is understood that when the light beam passes through the waveguide substrate 10 and the coupling grating 20 and reaches the first collimating element 30, it can be a polarized light beam. Both the first collimating element 30 and the second collimating element 40 include polarizing elements to collimate and correct aberrations in the polarized light beam. Furthermore, after passing through the first collimating element 30 and the second collimating element 40, the polarized light beam possesses a specific polarization state that the coupling grating 20 can respond to, allowing the polarized light beam to be coupled into the waveguide substrate 10 via the coupling grating 20.
[0044] For example, the first collimating element 30 and the second collimating element 40 may include a liquid crystal polarizing lens, and the coupling grating 20 may include a liquid crystal polarizing grating. It is understood that the liquid crystal polarizing lens and the liquid crystal polarizing grating can be prepared by spin-coating a liquid crystal solution onto an oriented substrate, wherein the liquid crystal solution includes liquid crystal molecules, a chiral agent, and a solvent. The oriented substrate can be prepared from a polymer solution that is responsive to polarized light beams.
[0045] For example, as shown in Figures 1 and 2, the coupling grating 20, the first collimating element 30, and the second collimating element 40 are correspondingly arranged. The coupling grating 20 only responds to left-hand circularly polarized beams. When the beam emitted by the image source 210 is transmitted to the waveguide substrate 10 and the coupling grating 20, it can be a right-hand circularly polarized beam. The right-hand circularly polarized beam can directly pass through the waveguide substrate 10 and the coupling grating 20 and be transmitted to the first collimating element 30. The first collimating element 30 includes a transmissive polarization element that responds to right-hand circularly polarized beams. The right-hand circularly polarized beam can be collimated, aberration corrected, and converted into a left-hand circularly polarized beam by the first collimating element 30. A polarized beam exits from the first collimating element 30 and is transmitted to the second collimating element 40. The second collimating element 40 includes a reflective polarizing element that responds to left-handed circularly polarized beams. The second collimating element 40 collimates, corrects aberrations, and reflects the left-handed circularly polarized beam, causing it to pass through the first collimating element 30 again. This time, the first collimating element 30 does not respond to the left-handed circularly polarized beam, and the left-handed circularly polarized beam passes directly through the first collimating element 30 and is transmitted to the coupling grating 20. The coupling grating 20 includes a reflective liquid crystal polarizing grating that responds to left-handed circularly polarized beams. After diffraction by the coupling grating 20, the beam is coupled into the waveguide substrate 10. During this process, the beam can be collimated twice by the first collimating element 30 and the second collimating element 40.
[0046] Furthermore, the liquid crystal molecules within the liquid crystal polarizing lens can be deflected under voltage. By controlling the voltage applied to the liquid crystal polarizing lens, the response of the liquid crystal polarizing lens to the polarized beam can be adjusted, thereby improving the adaptability of the optical module 100.
[0047] As shown in Figure 1, in some embodiments, the optical module 100 further includes a polarization modulator 60, which is disposed on the side of the waveguide substrate 10 opposite to the first collimating element 30. The polarization modulator 60 is used to modulate an unpolarized light beam into a polarized light beam, so that the light beam is a polarized light beam when it passes through the waveguide substrate 10 and the coupling grating 20 and is transmitted to the first collimating element 30. It can be understood that the light beam emitted by the image source 210 of the near-eye display device 200 may be an unpolarized light beam, which can be modulated by the polarization modulator 60 to make it a polarized light beam.
[0048] For example, the polarization modulator 60 includes a circular polarizer, as shown in FIG1. The unpolarized light beam emitted from the image source 210 can be modulated into right-hand circularly polarized light after passing through the polarization modulator 60. The coupling grating 20 can respond to the left-hand circularly polarized light, so that the right-hand circularly polarized light directly passes through the waveguide substrate 10 and the coupling grating 20 and is transmitted to the first collimating element 30. The reverse is also true.
[0049] In some embodiments, the light beam emitted by the image source 210 of the near-eye display device 200 is a polarized light beam.
[0050] As shown in Figure 3, in some embodiments, there are one or more first collimating elements 30. When there are multiple first collimating elements 30, they are arranged sequentially along the direction from the waveguide substrate 10 to the second collimating element 40. The light beam can be collimated sequentially by the multiple first collimating elements 30, then collimated by the second collimating element 40, and then reflected. It is understood that the number of first collimating elements 30 can be adjusted according to actual needs. By adjusting the number of first collimating elements 30, it is beneficial to enable the optical module 100 to meet higher requirements for the collimation effect of the light beam.
[0051] For example, the direction from the waveguide substrate 10 to the second collimating element 40 can be shown as the Z0-Z1 direction in Figure 3.
[0052] For example, as shown in FIG3, the optical module 100 includes two first collimating elements 30, which are located between the waveguide substrate 10 and the second collimating element 40. The two first collimating elements 30 are arranged sequentially along the direction from the waveguide substrate 10 to the second collimating element 40, and the light beam can be transmitted to the second collimating element 40 after passing through multiple first collimating elements 30.
[0053] For example, as shown in FIG3, the coupling grating 20, the first collimating element 30, and the second collimating element 40 are correspondingly arranged. The coupling grating 20 only responds to left-hand circularly polarized beams. When the beam emitted by the image source 210 is transmitted to the waveguide substrate 10 and the coupling grating 20, it can be a right-hand circularly polarized beam. The right-hand circularly polarized beam can directly pass through the waveguide substrate 10 and the coupling grating 20 and be transmitted to the first collimating element 30 near the Z0 side. The first collimating element 30 may include a transmissive polarization element that responds to right-hand circularly polarized beams. The right-hand circularly polarized beam can be collimated and converted into a left-hand circularly polarized beam by the first collimating element 30. The left-hand circularly polarized beam exits from the first collimating element 30 and is transmitted to the first collimating element 40 near the Z1 side. The lower first collimating element 30 may include a transmissive polarization element that responds to left-hand circularly polarized beams. The polarization element allows a left-handed circularly polarized beam to be collimated and converted into a right-handed circularly polarized beam by the first collimating element 30. This right-handed circularly polarized beam is then transmitted to a second collimating element 40, which includes a reflective polarizing element that responds to the right-handed circularly polarized beam. The second collimating element 40 collimates and reflects the right-handed circularly polarized beam, causing it to pass again through the first collimating element 30 near the Z1 side. At this point, the first collimating element 30 does not respond to the right-handed circularly polarized beam, and the beam passes directly through it to the first collimating element 30 near the Z0 side. The right-handed circularly polarized beam is then collimated again by the first collimating element 30 near the Z0 side and converted into left-handed circularly polarized light. This left-handed circularly polarized light propagates into the coupling waveguide and can be coupled into the waveguide substrate 10 via the coupling grating 20. In this process, the beam can be collimated three times by two first collimating elements 30 and one second collimating element 40, thereby enhancing the aberration correction capability of the optical module 100 for the incident beam.
[0054] In some embodiments, the coupling grating 50 is a non-polarizing grating capable of coupling out a non-polarizing beam.
[0055] It is worth noting that when the beam is incident on the grating 20, it can be a polarized beam. However, the polarized beam is easily converted into an unpolarized beam during its propagation within the waveguide substrate 10. Using an unpolarized grating can couple out the unpolarized beam.
[0056] In some embodiments, the coupling grating 50 is a polarization grating capable of coupling out polarized beams, or coupling out polarized rays with a specific polarization direction from an unpolarized beam.
[0057] Understandably, the output grating 50 can be a non-polarizing grating or a polarizing grating. The setting of the output grating 50 is quite flexible and can be adjusted according to actual needs.
[0058] As shown in Figure 1, in some embodiments, there are multiple coupling gratings 50, and all of the multiple coupling gratings 50 are polarization gratings.
[0059] For example, as shown in Figure 1, multiple coupling gratings 50 can be arranged sequentially along the direction from the waveguide substrate 10 to the second collimating element 40 as indicated by the Z0-Z1 direction in Figure 1; or, multiple coupling gratings 50 can be arranged sequentially along a direction perpendicular to the plane of the paper. It is understood that the positional relationship between the multiple coupling gratings 50 is quite flexible and can be adjusted according to actual conditions.
[0060] In some embodiments, the light beam is coupled out through a plurality of coupling gratings 50 and transmitted along a transmission direction.
[0061] For example, as shown in Figure 1, two coupling gratings 50 are arranged sequentially along the Z0-Z1 direction. One coupling grating 50 can couple out the left-hand circularly polarized light from the unpolarized beam transmitted within the waveguide substrate 10, and the other coupling grating 50 can couple out the right-hand circularly polarized light from the unpolarized beam transmitted within the waveguide substrate 10. The coupled light can be transmitted along the same transmission direction.
[0062] In some embodiments, there are multiple coupling gratings 50, and all of the multiple coupling gratings 50 are polarization gratings. The multiple coupling gratings 50 can expand the pupil of the light beam to form at least two light beams with different transmission directions, thereby optimizing the imaging effect.
[0063] For example, Figure 5 shows the K-vector diagram of an optical waveguide including two coupling gratings 50. The four rectangles in Figure 5 represent all k-vectors in the complete field of view of the beam. Points kip, k1p, k2p, and k3p represent the k-vectors at the central field of view during beam propagation, respectively. The annular region represents the total internal reflection region, where the k-vectors satisfy the total internal reflection condition and can propagate in the waveguide substrate. As shown in Figure 5, after the beam is incident with a k-vector and diffracted by the coupling grating 20, the beam is transported to the annular region by the grating vector Gip of the coupling grating 20. This represents the beam being coupled into the waveguide substrate 10 through total internal reflection. The two coupling gratings 50 are the first coupling grating and the second coupling grating, respectively. In the waveguide substrate 10, part of the beam transmitted is transported to the central region by the grating vector Gop1 of the first coupling grating and the grating vector Gop2 of the second coupling grating in sequence. This means that the beam is coupled out of the waveguide substrate 10 after being diffracted by the two coupling gratings 50. The other part is transported to the central region by the grating vector Gop2 of the second coupling grating and the grating vector Gop1 of the first coupling grating in sequence. The two parts of the beam have different transmission directions after being coupled out, thus achieving pupil expansion.
[0064] As shown in Figure 3, in some embodiments, the optical module 100 further includes a protective element 70, which is disposed on the side of the waveguide substrate 10 facing the first collimating element 30, and serves to protect the components of the optical module 100.
[0065] For example, the protective element 70 includes a cover or protective film layer, which may be made of glass or resin.
[0066] As shown in Figures 1, 3, and 4, the protective element 70 is further disposed between the first collimating element 30 and the waveguide substrate 10, or between the first collimating element 30 and the second collimating element 40. In this way, the light beam can pass through the protective element 70 before coupling into the waveguide substrate 10, extending the propagation path of the light beam while controlling the volume of the optical module 100, thereby optimizing aberrations and extending the function of the protective element 70.
[0067] For example, as shown in Figure 3, the protective element 70 is disposed between the first collimating element 30 and the second collimating element 40. The light beam exits from the first collimating element 30 and is transmitted to the second collimating element 40 after passing through the protective element 70. After the second collimating element 40 reflects the light beam, the light beam can pass through the protective element 70 and the first collimating element 30 again and be coupled into the optical waveguide via the coupling grating 20. The light beam passes through the protective element 70 twice during the transmission process, which helps to extend the propagation path of the light beam.
[0068] As shown in Figure 3, when there are multiple first collimating elements 30, the protective element 70 is disposed between at least one first collimating element 30 and the second collimating element 40, and the protective element 70 can be located between two adjacent first collimating elements 30.
[0069] Of course, in other embodiments, the protective element 70 may also be located on the side of the second collimating element 40 opposite to the first collimating element 30. The position of the protective element 70 is flexible and can be adjusted according to the actual situation.
[0070] As shown in Figure 4, in some embodiments, an optical adhesive layer 80 is provided between the protective element 70 and the waveguide substrate 10, so that the light beam can be coupled into the waveguide substrate 10 via the coupling grating 20 and then propagated within the waveguide substrate 10 and the protective element 70. By enabling the light beam to propagate within the waveguide substrate 10 and the protective element 70 through the optical adhesive layer 80 after being coupled into the waveguide substrate 10, it is beneficial to increase the degree of freedom of light beam propagation to meet different transmission requirements.
[0071] For example, as shown in FIG4, an optical adhesive layer 80 is provided between the protective member 70 and the waveguide substrate 10. After the light beam is coupled into the waveguide substrate 10 by the coupling grating 20, it can be transmitted within the waveguide substrate 10. When it is transmitted to the location of the optical adhesive layer 80, it is transmitted through the optical adhesive layer 80 into the protective member 70, and finally coupled out through the coupling grating 50.
[0072] For example, an optical adhesive layer 80 is provided between the protective member 70 and the waveguide substrate 10. The light beam can also be coupled into the waveguide substrate 10 by the coupling grating 20 and then transmitted within the waveguide substrate 10. When it reaches the location of the optical adhesive layer 80, it is transmitted through the optical adhesive layer 80 to the protective member 70. Then, when it is transmitted within the protective member 70 and then reaches the location of the optical adhesive layer 80 again, it can be transmitted through the optical adhesive layer 80 to the waveguide substrate 10 again.
[0073] Understandably, the propagation path of the light beam through the optical adhesive layer 80 within the waveguide substrate 10 and the protective element 70 can be adjusted according to the actual situation, and is not limited here.
[0074] Understandably, the coupling grating 50 can be disposed between the waveguide substrate 10 and the protective member 70, as shown in Figure 4. Alternatively, the coupling grating 50 can be disposed on the side of the waveguide substrate 10 away from the protective member 70. Or, the coupling grating 50 can be disposed on the side of the protective member 70 away from the waveguide substrate 10. That is, the coupling grating 50 is disposed on the waveguide substrate 10 through the protective member 70 and the optical adhesive layer 80.
[0075] This application embodiment also provides a near-eye display device 200, which includes the optical module 100 as described above. It is understood that the near-eye display device 200 with the optical module 100 described above also possesses all of its technical effects, namely, it can collimate the light beam emitted from the image source 210 through the first collimating element 30 and the second collimating element 40, enabling the light beam to be coupled parallel into the waveguide substrate 10 for efficient transmission within the waveguide substrate 10. Furthermore, the second collimating element 40 can reflect the light beam, which is beneficial for increasing the light beam propagation path to optimize aberrations while shortening the distance between the image source 210 and the waveguide substrate 10 of the near-eye display device 200, reducing the size of the near-eye display device 200, and achieving a miniaturized design of the near-eye display device 200.
[0076] For example, near-eye display device 200 includes image source 210, such as display screen.
[0077] For example, as shown in FIG1, when the optical module 100 is applied to the near-eye display device 200, by adjusting the parameters of the optical module 100, the image source 210 of the near-eye display device 200 can be made to fit with the optical module 100, thereby improving the space utilization of the near-eye display device 200 and reducing the volume of the near-eye display device 200.
[0078] For example, the near-eye display device 200 includes, but is not limited to, augmented reality (AR) display devices and virtual reality (VR) display devices.
[0079] It should be understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. It should be noted that, herein, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.
[0080] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. An optical module, comprising: Waveguide substrate; A coupling grating is disposed on one side of the waveguide substrate; The first collimating element is disposed on the side of the waveguide substrate away from the coupling grating, or on the side of the coupling grating away from the waveguide substrate. The second collimating element is disposed on the side of the first collimating element that is away from the waveguide substrate; A coupling grating is disposed on the waveguide substrate; The light beam can pass through the waveguide substrate and be transmitted to the first collimating element. The light beam emitted from the first collimating element is reflected by the second collimating element. The light beam emitted from the second collimating element is transmitted to the first collimating element and then coupled into the waveguide substrate via the coupling grating and transmitted within the waveguide substrate. It is then coupled out via the coupling grating. The first collimating element and the second collimating element are used to collimate the light beam.
2. The optical module according to claim 1, wherein, Both the first collimating element and the second collimating element include polarizing elements, and the coupling grating is a polarizing grating.
3. The optical module according to claim 2, wherein, The polarization element includes a liquid crystal polarizing lens.
4. The optical module according to claim 1, wherein, The first collimating element may be one or more; When there are multiple first collimating elements, the multiple first collimating elements are arranged sequentially along the direction from the waveguide substrate to the second collimating element.
5. The optical module according to claim 1, wherein, The coupled grating is either a non-polarizing grating or a polarizing grating.
6. The optical module according to claim 5, wherein, There are multiple coupling gratings, and each of the multiple coupling gratings is a polarization grating; The light beam is coupled out through a plurality of said coupling gratings and transmitted along a transmission direction, or the plurality of said coupling gratings can expand the pupil of the light beam to form at least two light beams with different transmission directions.
7. The optical module according to claim 1, wherein, The optical module also includes: A protective element is disposed on the side of the waveguide substrate facing the first collimating element.
8. The optical module according to claim 7, wherein, The protective element is disposed between the first collimating element and the waveguide substrate, or the protective element is disposed between the first collimating element and the second collimating element.
9. The optical module according to claim 8, wherein, An optical adhesive layer is provided between the protective element and the waveguide substrate to enable the light beam to be coupled into the waveguide substrate via the coupling grating and then transmitted within the waveguide substrate and the protective element.
10. A near-eye display device, comprising the optical module as described in any one of claims 1-9.