Optical module and near-to-eye display equipment

Abstract

The embodiment of the invention provides an optical module and a near-to-eye display device. The optical module comprises a waveguide substrate, a coupling-in grating, a first collimating element, a second collimating element and a coupling-out grating. The coupling-in grating is arranged on one side of the waveguide substrate. The first collimating element is arranged on the side, away from the coupling-in grating, of the waveguide substrate or the side, away from the waveguide substrate, of the coupling-in grating. The second collimating element is arranged on the side, away from the waveguide substrate, of the first collimating element. The coupling-out grating is arranged on the waveguide substrate. A light beam can penetrate through the waveguide substrate and is transmitted to the first collimating element, the light beam emitted from the first collimating element is reflected by the second collimating element, and the light beam emitted from the second collimating element is transmitted to the first collimating element, is coupled into the waveguide substrate through the coupling-in grating, is transmitted in the waveguide substrate, and is coupled out through the coupling-out grating. The first collimating element and the second collimating element are used for collimating the light beam. According to the technical scheme, the size of the near-to-eye display equipment is reduced.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to an optical module and a near-eye display device. Background Art

[0002] Near-eye display devices usually include a light engine and an optical waveguide. The light engine includes a display screen and an optical machine module. The optical machine module is located between the display screen and the optical waveguide and is used to collimate the light emitted by the display screen into parallel light and emit it toward the optical waveguide. At the same time, in order to more conveniently correct the aberration of light imaging in the human eye to improve the imaging quality, a certain number of glass-plastic hybrid lens groups are usually required in the related technology. There is usually a certain air gap between these lens groups. Therefore, when the light emitted by the display screen propagates to the coupling grating, there is a certain transmission length, that is, the total length of the system. This also causes the light engine in the near-eye display device to occupy a certain volume, which makes it difficult to achieve a lighter and thinner near-eye display device. Summary of the invention

[0003] Embodiments of the present invention provide an optical module and a near-eye display device, aiming to reduce the volume of the near-eye display device.

[0004] In a first aspect, an embodiment of the present invention provides an optical module, including:

[0005] waveguide substrate;

[0006] A coupling-in grating, disposed on one side of the waveguide substrate;

[0007] A first collimating element is arranged on a side of the waveguide substrate away from the coupling-in grating, or arranged on a side of the coupling-in grating away from the waveguide substrate;

[0008] A second collimating element, disposed on a side of the first collimating element away from the waveguide substrate;

[0009] An outcoupling grating is arranged on the waveguide substrate;

[0010] Among them, 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-in grating and transmitted in the waveguide substrate, and coupled out via the coupling-out grating; the first collimating element and the second collimating element are used to collimate the light beam.

[0011] Optionally, both the first collimating element and the second collimating element include polarization elements, and the coupling-in grating is a polarization grating.

[0012] Optionally, the polarizing element comprises a liquid crystal polarizing lens.

[0013] Optionally, the first collimating element is one or more;

[0014] When there are a plurality of the first collimating elements, the plurality of the first collimating elements are arranged in sequence along a direction from the waveguide substrate to the second collimating element.

[0015] Optionally, the outcoupling grating is a non-polarization grating or a polarization grating.

[0016] Optionally, the plurality of outcoupling gratings are polarization gratings;

[0017] The light beam is coupled out through the multiple outcoupling gratings and transmitted along one transmission direction, or the multiple outcoupling gratings can expand the pupil of the light beam to form at least two light beams with different transmission directions.

[0018] Optionally, the optical module further includes:

[0019] A protective member is arranged on a side of the waveguide substrate facing the first collimating element.

[0020] Optionally, the protective member is disposed between the first collimating element and the waveguide substrate, or the protective member is disposed between the first collimating element and the second collimating element.

[0021] Optionally, an optical adhesive layer is provided between the protective member and the waveguide substrate, so that the light beam can be transmitted within the waveguide substrate and the protective member after being coupled into the waveguide substrate via the coupling grating.

[0022] In a second aspect, an embodiment of the present invention further provides a near-eye display device, comprising the optical module described in the first aspect.

[0023] The embodiment of the present invention provides an optical module and a near-eye display device. When the optical module in the embodiment of the present invention is applied to the near-eye display device, the light beam emitted by the image source can be collimated by the first collimating element and the second collimating element before being coupled into the waveguide substrate, so that the light beam can be coupled into the waveguide substrate in parallel to be efficiently transmitted in the waveguide substrate. By adjusting the light beam by the first collimating element and the second collimating element, the light beam propagation path can be increased and the aberration can be optimized, and the distance between the image source and the waveguide substrate of the near-eye display device can be effectively shortened by folding the optical path, reducing the volume of the near-eye display device, and realizing the miniaturized design of the near-eye display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A schematic diagram of the structure of a near-eye display device provided by an embodiment of the present invention;

[0026] Figure 2 for Figure 1 Propagation path diagram of light beams at different viewing angles in a near-to-mid eye display device;

[0027] Figure 3 A schematic structural diagram of another near-eye display device provided by an embodiment of the present invention;

[0028] Figure 4 A schematic structural diagram of another near-eye display device provided by an embodiment of the present invention;

[0029] Figure 5 K-vector diagram of an optical waveguide when there are two outcoupling gratings provided in an embodiment of the present invention.

[0030] Description of main reference numerals:

[0031] 100, optical module; 10, waveguide substrate; 20, coupling-in grating; 30, first collimating element; 40, second collimating element; 50, coupling-out grating; 60, polarization modulator; 70, protective element; 80, optical adhesive layer;

[0032] 200. Near-eye display device; 210. Image source. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The flowcharts shown in the accompanying drawings are only examples and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may also be decomposed, combined or partially merged, so the actual execution order may change according to actual conditions.

[0035] It should be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0036] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0037] Please refer to Figure 1 and Figure 2 As shown, Figure 1 An optical module 100 is provided in an embodiment of the present invention. The optical module 100 includes a waveguide substrate 10, an in-coupling grating 20, a first collimating element 30, a second collimating element 40, and an out-coupling grating 50. The in-coupling grating 20 is arranged on one side of the waveguide substrate 10. The first collimating element 30 is arranged on a side of the waveguide substrate 10 away from the in-coupling grating 20, or, on a side of the in-coupling grating 20 away from the waveguide substrate 10. The second collimating element 40 is arranged on a side of the first collimating element 30 away from the waveguide substrate 10. The out-coupling grating 50 is arranged 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 emitted from the first collimating element 30 is reflected by the second collimating element 40. The light beam emitted from the second collimating element 40 is transmitted to the first collimating element 30 and then coupled into the waveguide substrate 10 via the coupling-in grating 20 and transmitted in the waveguide substrate 10, and then coupled out via the coupling-out grating 50. The first collimating element 30 and the second collimating element 40 are used to collimate and correct aberrations of the light beam.

[0038] Understandable, such as Figure 1 As shown, 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, so as to be efficiently transmitted in the waveguide substrate 10. In addition, by adjusting the light beam through the first collimating element 30 and the second collimating element 40, the light beam propagation path can be increased and the aberration can be optimized, and the distance between the image source 210 and the waveguide substrate 10 of the near-eye display device 200 can be effectively shortened by folding the optical path, thereby reducing the volume of the near-eye display device 200 and realizing the miniaturized design of the near-eye display device 200.

[0039] For example, the waveguide substrate 10 may be made of glass or resin.

[0040] Exemplarily, the coupling-in grating 20 may be a transmission grating or a reflection grating, and the coupling-out grating 50 may be a transmission grating or a reflection grating.

[0041] like Figure 1 As shown, in some embodiments, the light beam can be transmitted through the waveguide substrate 10 and the coupling grating 20 and then transmitted to the first collimating element 30, emitted from the first collimating element 30 to the second collimating element 40, reflected by the second collimating element 40, and then emitted to the coupling grating 20 after passing through the first collimating element 30 again, and the coupling grating 20 couples the light beam into the waveguide substrate 10. In this way, it is beneficial for the light beam to be 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, thereby improving the coupling efficiency.

[0042] In some embodiments, in the direction from the waveguide substrate 10 to the second collimating element 40, the coupling grating 20, the first collimating element 30 and the second collimating element 40 are correspondingly arranged, so that the light beam emitted by the image source 210 can pass through the waveguide substrate 10 and the coupling grating 20 and then be transmitted to the first collimating element 30, and then be emitted from the first collimating element 30 to the second collimating element 40, and then be reflected by the second collimating element 40, and then pass through the first collimating element 30 again and then be emitted to the coupling grating 20, and the coupling grating 20 couples the light beam into the waveguide substrate 10.

[0043] For example, the direction from the waveguide substrate 10 to the second collimating element 40 may be as follows: Figure 1 As shown in the Z0-Z1 direction.

[0044] In some embodiments, the first collimating element 30 and the second collimating element 40 both include polarization elements, and the coupling-in grating 20 includes a polarization grating. It can be understood that the light beam can be a polarized light beam when it passes through the waveguide substrate 10 and the coupling-in grating 20 and is transmitted to the first collimating element 30. The first collimating element 30 and the second collimating element 40 both include polarization elements, so that the polarized light beam can be collimated and aberration corrected by using the first collimating element 30 and the second collimating element 40. And after passing through the first collimating element 30 and the second collimating element 40, the polarized light beam has a specific polarization state that the coupling-in grating 20 can respond to, so that the polarized light beam can be coupled into the waveguide substrate 10 via the coupling-in grating 20.

[0045] Exemplarily, the first collimating element 30 and the second collimating element 40 may include a liquid crystal polarization lens, and the coupling grating 20 may include a liquid crystal polarization grating. It is understood that the liquid crystal polarization lens and the liquid crystal polarization grating may be prepared by spin coating a liquid crystal solution on a substrate having an orientation capability, wherein the liquid crystal solution includes liquid crystal molecules, a chiral agent, and a solvent. The substrate having an orientation capability may be prepared from a polymer solution having a responsiveness to a polarized light beam.

[0046] For example, Figure 1 and Figure 2As shown, 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 the left-handed circularly polarized light beam, the light beam emitted by the image source 210 can be a right-handed circularly polarized light beam when it is transmitted to the waveguide substrate 10 and the coupling grating 20, the right-handed circularly polarized light 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 transmission polarization element that responds to the right-handed circularly polarized light beam, the right-handed circularly polarized light beam can be collimated, aberration corrected and converted into a left-handed circularly polarized light beam through the first collimating element 30, and the left-handed circularly polarized light beam is transmitted from The first collimating element 30 emits and transmits to the second collimating element 40, the second collimating element 40 includes a reflective polarization element that responds to the left-handed circularly polarized light beam, the second collimating element 40 collimates, corrects the aberration and reflects the left-handed circularly polarized light beam, so that the left-handed circularly polarized light beam passes through the first collimating element 30 again, at this time the first collimating element 30 does not respond to the left-handed circularly polarized light beam, the left-handed circularly polarized light beam directly passes through the first collimating element 30 and is transmitted to the coupling grating 20, the coupling grating 20 includes a reflective liquid crystal polarization grating that responds to the left-handed circularly polarized light beam, and is coupled into the waveguide substrate 10 after diffraction through the coupling grating 20. In this process, the light beam can be collimated twice through the first collimating element 30 and the second collimating element 40.

[0047] Furthermore, the liquid crystal molecules in the liquid crystal polarization lens can be deflected under the action of voltage. By controlling the voltage applied to the liquid crystal polarization lens, the response of the liquid crystal polarization lens to the polarized light beam can be adjusted, thereby improving the adaptability of the optical module 100.

[0048] like Figure 1 As shown, in some embodiments, the optical module 100 further includes a polarization modulator 60, which is disposed on a side of the waveguide substrate 10 away from the first collimating element 30, and the polarization modulator 60 is used to modulate a non-polarized light beam into a polarized light beam, so that the light beam is a polarized light beam when passing through the waveguide substrate 10 and the coupling grating 20 and 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 can be a non-polarized light beam, and the light beam can be modulated by the polarization modulator 60 so that it is modulated from a non-polarized light beam to a polarized light beam.

[0049] Exemplarily, the polarization modulator 60 includes a circular polarizer, such as Figure 1 As shown, the unpolarized light beam emitted by the image source 210 can be modulated into right-handed circularly polarized light after passing through the polarization modulator 60, and the coupling-in grating 20 can respond to the left-handed circularly polarized light, so that the right-handed circularly polarized light directly passes through the waveguide substrate 10 and the coupling-in grating 20 and is transmitted to the first collimating element 30. Vice versa.

[0050] In some embodiments, the light beam emitted by the image source 210 of the near-eye display device 200 is a polarized light beam.

[0051] like Figure 3 As shown, in some embodiments, there are one or more first collimating elements 30. When there are multiple first collimating elements 30, the multiple first collimating elements 30 are sequentially arranged along the direction from the waveguide substrate 10 to the second collimating element 40, and the light beam can be collimated by the multiple first collimating elements 30 in sequence and then collimated and reflected by the second collimating element 40. It can be understood that the number of the first collimating elements 30 can be adjusted according to actual needs. By adjusting the number of the first collimating elements 30, it is helpful to make the collimation effect of the optical module 100 on the light beam meet higher requirements.

[0052] For example, the direction from the waveguide substrate 10 to the second collimating element 40 may be as follows: Figure 3 As shown in the Z0-Z1 direction.

[0053] For example, Figure 3 As shown, the optical module 100 includes two first collimating elements 30, the two first collimating elements 30 are located between the waveguide substrate 10 and the second collimating element 40, and the two first collimating elements 30 are arranged in sequence 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.

[0054] For example, Figure 3As shown, 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 the left-handed circularly polarized light beam, the light beam emitted by the image source 210 can be a right-handed circularly polarized light beam when it is transmitted to the waveguide substrate 10 and the coupling grating 20, the right-handed circularly polarized light beam can directly pass through the waveguide substrate 10 and the coupling grating 20 and be transmitted to the first collimating element 30 close to the Z0 side, the first collimating element 30 may include a transmission polarization element that responds to the right-handed circularly polarized light beam, the right-handed circularly polarized light beam can be collimated by the first collimating element 30 and converted into a left-handed circularly polarized light beam, the left-handed circularly polarized light beam is emitted from the first collimating element 30 and transmitted to the first collimating element 30 close to the Z1 side, the first collimating element 30 below may include a transmission polarization element that responds to the left-handed circularly polarized light beam , the left-handed circularly polarized light beam can be collimated and converted into a right-handed circularly polarized light beam through the first collimating element 30, and the right-handed circularly polarized light beam is transmitted to the second collimating element 40, and the second collimating element 40 includes a reflective polarization element that responds to the right-handed circularly polarized light beam. The second collimating element 40 collimates and reflects the right-handed circularly polarized light beam, so that the right-handed circularly polarized light beam passes through the first collimating element 30 near the Z1 side again. At this time, the first collimating element 30 does not respond to the right-handed circularly polarized light beam, and the right-handed circularly polarized light beam directly passes through the first collimating element 30 and is transmitted to the first collimating element 30 near the Z0 side. The right-handed circularly polarized light beam is collimated again through the first collimating element 30 near the Z0 side and converted into left-handed circularly polarized light. The left-handed circularly polarized light is transmitted to the coupling waveguide and can be coupled into the waveguide substrate 10 through the coupling grating 20. In this process, the light beam can be collimated three times through 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 light beam.

[0055] In some embodiments, the outcoupling grating 50 is a non-polarization grating capable of outcoupling a non-polarized light beam.

[0056] It is worth noting that the light beam can be a polarized light beam when incident on the grating 20, and the polarized light beam can be easily converted into a non-polarized light beam during transmission in the waveguide substrate 10. The non-polarization grating can be used to couple out the non-polarized light beam.

[0057] In some embodiments, the outcoupling grating 50 is a polarization grating, which can couple out a polarized light beam, or couple out polarized light with a specific polarization direction in a non-polarized light beam.

[0058] It can be understood that the outcoupling grating 50 can be a non-polarization grating or a polarization grating. The configuration of the outcoupling grating 50 is relatively flexible and can be adjusted according to actual needs.

[0059] like Figure 1 As shown, in some embodiments, there are multiple outcoupling gratings 50, and all of the multiple outcoupling gratings 50 are polarization gratings.

[0060] For example, the plurality of outcoupling gratings 50 may be Figure 1 As shown, along Figure 1 The plurality of outcoupling gratings 50 may be sequentially arranged in the direction from the waveguide substrate 10 to the second collimating element 40 as shown in the Z0-Z1 direction in FIG. 1 , or the plurality of outcoupling gratings 50 may be sequentially arranged in the direction perpendicular to the paper surface. It can be understood that the positional relationship between the plurality of outcoupling gratings 50 is relatively flexible and can be adjusted according to actual conditions.

[0061] In some embodiments, the light beam is coupled out through a plurality of outcoupling gratings 50 and transmitted along a transmission direction.

[0062] For example, Figure 1 As shown, two outcoupling gratings 50 are arranged in sequence along the Z0-Z1 direction, one of the outcoupling gratings 50 can couple out the left-handed circularly polarized light in the non-polarized light beam transmitted in the waveguide substrate 10, and the other outcoupling grating 50 can couple out the right-handed circularly polarized light in the non-polarized light beam transmitted in the waveguide substrate 10, and the coupled light can all be transmitted along the same transmission direction.

[0063] In some embodiments, there are multiple outcoupling gratings 50, and all of the multiple outcoupling gratings 50 are polarization gratings. The multiple outcoupling 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.

[0064] For example, Figure 5 The K-vector diagram of the optical waveguide is shown when the optical waveguide includes two outcoupling gratings 50. Figure 5 The four rectangles in the figure represent all k vectors in the complete field of view of the beam. Points kip, k1p, k2p, and k3p represent the k vectors in the central field of view during the propagation of the beam. The annular area represents the total reflection area. The k vectors in this area meet the total reflection conditions and can propagate in the waveguide substrate. Figure 5 It can be seen that after the light beam is incident with the k vector and diffracted by the coupling grating 20, the light beam is transported to the annular area by the grating vector Gip of the coupling grating 20, which means that the light beam is coupled into the waveguide substrate 10 through total reflection propagation. The two coupling gratings 50 are the first coupling grating and the second coupling grating, respectively. Then, among the light beams transmitted in the waveguide substrate 10, a part is transported to the central area in sequence via the grating vector Gop1 of the first coupling grating and the grating vector Gop2 of the second coupling grating, which means that the light beam is coupled out of the waveguide substrate 10 after being diffracted by the two coupling gratings 50, and the other part is transported to the central area in sequence via the grating vector Gop2 of the second coupling grating and the grating vector Gop1 of the first coupling grating. The transmission directions of the two parts of the light beams after coupling out are different, so pupil expansion is achieved.

[0065] like Figure 3As shown, in some embodiments, the optical module 100 further includes a protective member 70 . The protective member 70 is disposed on a side of the waveguide substrate 10 facing the first collimating element 30 , and serves to protect components of the optical module 100 .

[0066] Exemplarily, the protective member 70 includes a cover plate or a protective film layer, and the cover plate may be made of glass or resin.

[0067] like Figure 1 , Figure 3 and Figure 4 As shown, further, the protective member 70 is disposed between the first collimating element 30 and the waveguide substrate 10, or the protective member 70 is disposed between the first collimating element 30 and the second collimating element 40. In this way, the light beam can also pass through the protective member 70 before being coupled into the waveguide substrate 10, thereby controlling the volume of the optical module 100 and extending the propagation path of the light beam, so as to optimize the aberration and realize the functional extension of the protective member 70.

[0068] For example, Figure 3 As shown, the protective member 70 is disposed between the first collimating element 30 and the second collimating element 40. The light beam is emitted from the first collimating element 30 and is transmitted to the second collimating element 40 after passing through the protective member 70. After the second collimating element 40 reflects the light beam, the light beam can pass through the protective member 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 member 70 twice during transmission, which is beneficial to extend the propagation path of the light beam.

[0069] like Figure 3 As shown, when there are multiple first collimating elements 30 , the protective member 70 is disposed between at least one first collimating element 30 and the second collimating element 40 , and the protective member 70 may be located between two adjacent first collimating elements 30 .

[0070] Of course, in other embodiments, the protective member 70 may also be disposed on a side of the second collimating element 40 away from the first collimating element 30. The location of the protective member 70 is relatively flexible and can be adjusted according to actual conditions.

[0071] like Figure 4 As shown, in some embodiments, an optical adhesive layer 80 is provided between the protective member 70 and the waveguide substrate 10, so that the light beam can be transmitted in the waveguide substrate 10 and the protective member 70 after being coupled into the waveguide substrate 10 via the coupling grating 20. By allowing the light beam to be transmitted in the waveguide substrate 10 and the protective member 70 through the optical adhesive layer 80 after being coupled into the waveguide substrate 10, the degree of freedom of light beam transmission is increased to meet different transmission requirements.

[0072] For example, Figure 4As shown, 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-in grating 20, it can be transmitted in the waveguide substrate 10, and when it is transmitted to the position where the optical adhesive layer 80 is located, it is transmitted into the protective member 70 through the optical adhesive layer 80, and finally coupled out through the coupling-out grating 50.

[0073] Exemplarily, an optical adhesive layer 80 is provided between the protective member 70 and the waveguide substrate 10. The light beam may be coupled into the waveguide substrate 10 by the coupling grating 20 and then transmitted in the waveguide substrate 10. When the light beam is transmitted to the position where the optical adhesive layer 80 is located, the light beam may be transmitted to the protective member 70 through the optical adhesive layer 80. Then, when the light beam is transmitted in the protective member 70 and is transmitted to the position where the optical adhesive layer 80 is located again, the light beam may be transmitted to the waveguide substrate 10 again through the optical adhesive layer 80.

[0074] It can be understood that the transmission path of the light beam through the optical adhesive layer 80 in the waveguide substrate 10 and the protective member 70 can be adjusted according to actual conditions and is not limited here.

[0075] It can be understood that the outcoupling grating 50 can be disposed between the waveguide substrate 10 and the protective member 70, such as Figure 4 As shown, the outcoupling grating 50 may be disposed on the side of the waveguide substrate 10 away from the protective member 70, or alternatively, the outcoupling grating 50 may be disposed on the side of the protective member 70 away from the waveguide substrate 10, that is, the outcoupling grating 50 is disposed on the waveguide substrate 10 through the protective member 70 and the optical adhesive layer 80.

[0076] The embodiment of the present invention further provides a near-eye display device 200, and the near-eye display device 200 includes the optical module 100 as described above. It can be understood that the near-eye display device 200 having the optical module 100 described above also has all its technical effects, that is, it can collimate the light beam emitted by the image source 210 through the first collimating element 30 and the second collimating element 40, so that the light beam can be coupled into the waveguide substrate 10 in parallel, so as to be efficiently transmitted in the waveguide substrate 10. In addition, the second collimating element 40 can reflect the light beam, which is beneficial to increase the propagation path of the light beam so as to optimize the aberration, shorten the distance between the image source 210 of the near-eye display device 200 and the waveguide substrate 10, reduce the volume of the near-eye display device 200, and realize the miniaturized design of the near-eye display device 200.

[0077] Exemplarily, the near-eye display device 200 includes an image source 210 , such as a display screen.

[0078] For example, Figure 1As shown, when the optical module 100 is applied to the near-eye display device 200, the image source 210 of the near-eye display device 200 can be fitted with the optical module 100 by adjusting the parameters of 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.

[0079] Exemplarily, the near-eye display device 200 includes, but is not limited to, an augmented reality (AR) display device and a virtual reality (VR) display device.

[0080] It should be understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, including these combinations. It should be noted that, in this article, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "including a..." does not exclude the presence of other identical elements in the process, method, article or system including the element.

[0081] The serial numbers of the embodiments of the present invention are only for description and do not represent the advantages and disadvantages of the embodiments. The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. An optical module, characterized in that: include: waveguide substrate; A coupling-in grating, disposed on one side of the waveguide substrate; A first collimating element is arranged on a side of the waveguide substrate away from the coupling-in grating, or arranged on a side of the coupling-in grating away from the waveguide substrate; A second collimating element, disposed on a side of the first collimating element away from the waveguide substrate; An outcoupling grating is arranged on the waveguide substrate; Among them, 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-in grating and transmitted in the waveguide substrate, and coupled out via the coupling-out 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, characterized in that The first collimating element and the second collimating element both include polarization elements, and the coupling-in grating is a polarization grating.

3. The optical module according to claim 2, characterized in that: The polarizing element includes a liquid crystal polarizing lens.

4. The optical module according to any one of claims 1 to 3, characterized in that: The first collimating element is one or more; When there are a plurality of the first collimating elements, the plurality of the first collimating elements are arranged in sequence along a direction from the waveguide substrate to the second collimating element.

5. The optical module according to any one of claims 1 to 3, characterized in that: The outcoupling grating is a non-polarization grating or a polarization grating.

6. The optical module according to claim 5, characterized in that There are multiple outcoupling gratings, and all of the multiple outcoupling gratings are polarization gratings; The light beam is coupled out through the multiple outcoupling gratings and transmitted along one transmission direction, or the multiple outcoupling 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 any one of claims 1 to 3, characterized in that: The optical module also includes: A protective member is arranged on a side of the waveguide substrate facing the first collimating element.

8. The optical module according to claim 7, characterized in that: The protection member is disposed between the first collimating element and the waveguide substrate, or the protection member is disposed between the first collimating element and the second collimating element.

9. The optical module according to claim 8, characterized in that An optical adhesive layer is provided between the protection member and the waveguide substrate, so that the light beam can be transmitted in the waveguide substrate and the protection member after being coupled into the waveguide substrate via the coupling grating.

10. A near-eye display device, characterized in that: Comprising the optical module according to any one of claims 1-9.

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