Optical waveguide device and head-mounted display equipment

Abstract

The embodiment of the invention discloses an optical waveguide device and head-mounted display equipment. The optical waveguide device comprises a waveguide substrate, a coupling-in area and a coupling-out area, wherein the coupling-in area and the coupling-out area are arranged on the waveguide substrate; the coupling-in area is provided with a coupling-in grating used for coupling light into the waveguide substrate. The coupling-out area is provided with a coupling-out grating, the coupling-out grating comprises a grating array formed by a plurality of grating units, the cross section of each grating unit is a polygon, each grating unit comprises at least one arc edge, the arc edge meets a hyperelliptic equation # imgabs0 #, and n, a and b are positive numbers.

Description

Technical Field

[0001] The present application belongs to the technical field of optical devices. Specifically, the present application relates to an optical waveguide device and a head-mounted display device. Background Art

[0002] Augmented Reality (AR) is a technology that cleverly integrates virtual information with the real world. Currently, optical waveguide devices are usually used to implement augmented reality solutions.

[0003] In the existing related technologies, an optical waveguide device includes a waveguide substrate, on which an in-coupling grating and an out-coupling grating are arranged. Light enters the waveguide substrate through the in-coupling grating, and then is coupled out through the out-coupling grating. The out-coupling grating is set as a two-dimensional grating. In the prior art, the grating unit of the out-coupling grating is usually set as a polygon formed by straight lines. However, when light is coupled into such an out-coupling grating, a bright line in the middle will appear, and at the same time, the splitting energy on both sides will be reduced, which is not conducive to the expansion of light energy and affects the light output uniformity of the optical waveguide device. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a new technical solution for an optical waveguide device and a head-mounted display device.

[0005] According to a first aspect of an embodiment of the present application, there is provided an optical waveguide device, comprising:

[0006] A waveguide substrate, and an incoupling region and an outcoupling region disposed on the waveguide substrate;

[0007] The coupling-in region is provided with a coupling-in grating for coupling light into the waveguide substrate;

[0008] The coupling-out region is provided with a coupling-out grating, the coupling-out grating comprises a grating array formed by a plurality of grating units, each of the grating units has a polygonal cross section, the grating unit comprises at least one arc edge, and the arc edge satisfies a superellipse equation Where n, a and b are positive numbers.

[0009] Optionally, the grating unit further includes at least one straight edge, and the arc edge and the straight edge form a polygon.

[0010] Optionally, the grating unit includes two arc sides and two straight sides, and the two arc sides and the two straight sides enclose a quadrilateral.

[0011] Optionally, the grating unit includes a plurality of arc edges, and the plurality of arc edges are enclosed to form a polygon.

[0012] Optionally, n>1, the arc edge is set to be a convex arc edge, and a plurality of the convex arc edges are enclosed to form a polygon.

[0013] Optionally, when n<1, the arc edge is set to be a concave arc edge, and a plurality of the concave arc edges are enclosed to form a polygon.

[0014] Optionally, the arc edge includes at least one convex arc edge and at least one concave arc edge, wherein when n>1, it is a convex arc edge, and when n<1, it is a concave arc edge.

[0015] Optionally, the value range of n is: 0.5≤n≤1.5.

[0016] Optionally, the grating vector of the coupling-in grating is K1, and the grating vectors of the coupling-out grating are K2 and K3 respectively, and K1, K2 and K3 form a closed vector triangle.

[0017] According to a second aspect of an embodiment of the present application, a head-mounted display device is also provided, comprising the optical waveguide device described in the first aspect.

[0018] One technical effect of the embodiment of the present application is:

[0019] Compared with the grating unit composed of straight lines in the prior art, the grating unit of the outcoupling grating in the present application is set as a polygon containing at least one arc edge, and the arc edge satisfies the superellipse equation. The outcoupling grating formed by the grating unit can better regulate the distribution of the outcoupling efficiency of the diffraction optical waveguide, which is conducive to improving the outcoupling effect of the light of the optical waveguide device and the uniformity of the outcoupling light. The display device with such a diffraction optical waveguide has the advantages of high brightness and high uniformity.

[0020] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0022] Figure 1 A structural diagram of an optical waveguide device provided in an embodiment of the present application;

[0023] Figure 2 One of the structural schematic diagrams of the grating unit provided in the embodiment of the present application;

[0024] Figure 3 The second structural diagram of the grating unit provided in the embodiment of the present application;

[0025] Figure 4 The third structural diagram of the grating unit provided in the embodiment of the present application;

[0026] Figure 5 A fourth structural diagram of a grating unit provided in an embodiment of the present application;

[0027] Figure 6 A fifth structural diagram of a grating unit provided in an embodiment of the present application;

[0028] Figure 7 This is a light path diagram of the optical waveguide device provided in an embodiment of the present application.

[0029] Description of reference numerals:

[0030] 100, waveguide substrate; 110, coupling-in region; 111, coupling-in grating; 120, coupling-out region; 121, coupling-out grating; 1201, grating unit; 1202, straight edge; 1203, convex arc edge; 1204, concave arc edge; 1001, first diffraction ray; 1002, second diffraction ray; 1003, first output ray; 1004, third diffraction ray; 1005, second output ray. DETAILED DESCRIPTION

[0031] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0032] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0033] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0034] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0035] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0036] According to an embodiment of the present application, an optical waveguide device is provided, which can be applied to, for example, an augmented reality device. The augmented reality device includes, for example, AR smart glasses, AR helmets, etc., which are not limited in the embodiments of the present application.

[0037] The present application embodiment provides an optical waveguide device, referring to Figure 1, the optical waveguide device comprises a waveguide substrate 100, and an incoupling region 110 and an outcoupling region 120 arranged on the waveguide substrate 100;

[0038] The coupling-in region 110 is provided with a coupling-in grating 111 for coupling light into the waveguide substrate 100;

[0039] The outcoupling region 120 is provided with an outcoupling grating 121, and the outcoupling grating 121 includes a grating array formed by a plurality of grating units 1201, each of the grating units 1201 has a polygonal cross section, and the grating unit 1201 includes at least one arc edge, and the arc edge satisfies the superellipse equation Where n, a and b are positive numbers.

[0040] The optical waveguide device includes a waveguide substrate 100, on which an incoupling region 110 and an outcoupling region 120 are arranged. The waveguide substrate 100 includes a first surface and a second surface arranged opposite to each other, and the incoupling region 110 and the outcoupling region 120 can be arranged on at least one of the first surface and the second surface of the waveguide substrate 100. In the embodiment of the present application, the arrangement of the incoupling region 110 and the outcoupling region 120 on the waveguide substrate 100 is not limited. That is, it includes but is not limited to Figure 1 As shown in FIG. 1 , the coupling-in region 110 and the coupling-out region 120 are disposed on the same surface of the waveguide substrate 100 , for example, the first surface.

[0041] In the embodiment of the present application, the coupling region 110 is provided with a coupling grating 111. The coupling grating 111 is used to couple light into the waveguide substrate 100. The coupling grating 111 includes at least one one-dimensional grating. That is, including but not limited to Figure 2 As shown in FIG. 1 , the coupling grating 111 is composed of a one-dimensional grating. The coupling grating 111 may also be composed of two one-dimensional gratings. Of course, the coupling grating 111 may also be composed of a one-dimensional grating and a two-dimensional grating. The present application does not limit the specific structure of the coupling grating 111, as long as the coupling grating 111 can couple the incident light into the waveguide substrate 100.

[0042] In the embodiment of the present application, the outcoupling region 120 is provided with an outcoupling grating 121. The outcoupling grating 121 is set as a two-dimensional grating. The outcoupling grating 121 includes a plurality of grating units 1201, and the plurality of grating units 1201 are arranged in an array to form the outcoupling grating 121. That is, each grating unit 1201 is also the minimum repeating unit of the outcoupling grating 121.

[0043] The grating unit 1201 is a polygon along a cross section parallel to the waveguide substrate 100. The grating unit 1201 includes at least one arc edge, and the arc edge satisfies the superellipse equation In the equation of a superellipse, n, a, and b are positive numbers. a and b are the major and minor axes of the arc, respectively. n is the power of the superellipse.

[0044] The hyperelliptic equation is expressed as a parametric equation as follows:

[0045] x = a*cos(t)^(2 / n);

[0046] y=a*sin(t)^2 / n.

[0047] As the value of the superellipse power n changes, the superellipse equation can achieve seamless changes from asteroid curves, prisms, ellipses, and superellipse shapes.

[0048] It should be noted that the grating unit 1201 is set to a polygon, for example, the cross section of the grating unit 1201 is a triangle, a quadrilateral, a pentagon, etc. The polygon may be a symmetrical figure, and of course, the polygon may also be set to an asymmetrical figure. The present application does not limit the specific shape of the grating unit 1201, as long as the grating unit 1201 includes at least one arc edge that conforms to the superellipse equation.

[0049] Compared with the grating unit 1201 composed of straight lines in the prior art, the grating unit 1201 of the outcoupling grating 121 in the present application is set to a polygon containing at least one arc edge, and the arc edge satisfies the superellipse equation. The outcoupling grating 121 formed by the grating unit 1201 can better regulate the distribution of the outcoupling efficiency of the diffraction optical waveguide, which is conducive to improving the outcoupling effect of the light of the optical waveguide device and the uniformity of the outcoupling light. Therefore, the display device with such a diffraction optical waveguide has the advantages of high brightness and high uniformity.

[0050] In the embodiment of the present application, the grating unit 1201 further includes at least one straight edge 1202 , and the arc edge and the straight edge 1202 enclose a polygon.

[0051] That is, the grating unit 1201 includes at least one arc edge and at least one straight edge 1202. The arc edge and the straight edge 1202 enclose a polygon, such as a triangle, a quadrilateral, a pentagon, a hexagon, etc.

[0052] In one embodiment of the present application, the grating unit 1201 may be configured as a triangle, wherein:

[0053] The grating unit 1201 is, for example, a triangle formed by an arc side and two straight sides 1202. The arc side is any arc line that satisfies the super ellipse equation.

[0054] The grating unit 1201 is, for example, formed into a triangle by two arc edges and a straight edge 1202. The two arc edges are, for example, arc edges with the same curvature. The two arc edges satisfy the superellipse equation with the same parameters, and the two arc edges are symmetrically arranged about the X direction or the Y direction, wherein the X direction and the Y direction are two directions on the waveguide substrate 100 and the two directions are arranged perpendicularly. Of course, the two arc edges can also be arranged as arc edges with different curvatures, and the two arc edges respectively satisfy the superellipse equation with different parameters.

[0055] The grating unit 1201 may also be enclosed by an arc edge and two straight edges 1202 to form a triangle, for example.

[0056] Similarly, in another embodiment of the present application, the grating unit 1201 can also be set as a pentagon.

[0057] The grating unit 1201 is, for example, formed by an arc edge and four straight edges 1202 ;

[0058] The grating unit 1201 is, for example, formed by two arc edges and three straight edges 1202;

[0059] The grating unit 1201 is, for example, formed by three arc edges and two straight edges 1202;

[0060] The grating unit 1201 is, for example, formed by four arc edges and a straight edge 1202;

[0061] The grating unit 1201 is, for example, formed by five arc edges.

[0062] Similarly, in another embodiment of the present application, the grating unit 1201 can also be set as a quadrilateral.

[0063] The grating unit 1201 is, for example, surrounded by an arc edge and three straight edges 1202 .

[0064] The grating unit 1201 is, for example, surrounded by three arc edges and a straight edge 1202. The three arc edges are, for example, arc edges with the same curvature, and the three arc edges satisfy the super ellipse equation with the same parameters. Of course, the three arc edges can also be set to arc edges with different curvatures, and the three arc edges satisfy at least two sets of super ellipse equations with different parameters.

[0065] In the embodiment of the present application, the grating unit 1201 includes two arc edges and two straight edges 1202 , and the two arc edges and the two straight edges 1202 enclose a quadrilateral.

[0066] Reference Figure 2In one embodiment of the present application, the grating unit 1201 is enclosed by two arc edges and two straight edges 1202 to form a quadrilateral. Preferably, the two arc edges are symmetrically distributed along the Y axis. The two straight edges 1202 are also symmetrically distributed along the Y axis. The grating unit 1201 is set to a symmetrical quadrilateral structure.

[0067] Of course, the two arc edges may also be symmetrically distributed along the X-axis, and the two straight edges 1202 may also be symmetrically distributed along the X-axis.

[0068] By setting the grating unit 1201 to a symmetrical four-deformation structure formed by two arc edges and two straight edges 1202, it is beneficial to better control the distribution of the outcoupling efficiency of the diffraction optical waveguide, and to improve the outcoupling effect of the light of the optical waveguide device and the uniformity of the outcoupling light. Therefore, the display device with such a diffraction optical waveguide has the advantages of high brightness and high uniformity.

[0069] In the embodiment of the present application, the grating unit 1201 includes a plurality of arc edges, and the plurality of arc edges are enclosed to form a polygon.

[0070] In one embodiment of the present application, the grating unit 1201 may be formed by only a plurality of arc edges, wherein the grating unit 1201 is, for example, set to be a triangle, a quadrilateral, a pentagon, a hexagon, etc. That is, the grating unit 1201 includes three arc edges, four arc edges, five arc edges, six arc edges, etc.

[0071] It should be noted that the multiple arc edges are, for example, arc structures with the same parameters. Of course, the multiple arc edges can also be set as arc structures with different parameters. The parameter is the value of the power n of the super ellipse equation.

[0072] In the embodiment of the present application, n>1, the arc edge is set to a convex arc edge 1203, and a plurality of the convex arc edges 1203 are enclosed to form a polygon.

[0073] When n>1, the arc edge that satisfies the superellipse equation is set as a convex arc edge 1203. That is, the arc edge is convex toward the side away from the center of the grating unit 1201.

[0074] Reference Figure 3 In one embodiment of the present application, the grating unit 1201 includes four convex arc edges 1203, and the four convex arc edges 1203 enclose a quadrilateral. The quadrilateral formed by the four convex arc edges 1203 is symmetrically arranged about the X axis and the Y axis.

[0075] Of course, the grating unit 1201 may also include three convex arc edges 1203 to form a triangle, five convex arc edges 1203 to form a pentagon, or six convex arc edges 1203 to form a hexagon.

[0076] In the embodiment of the present application, when n<1, the arc edge is set to be a concave arc edge 1204, and a plurality of the concave arc edges 1204 are enclosed to form a polygon.

[0077] When n<1, the arc edge in the superellipse equation is set as a concave arc edge 1204 , that is, the arc edge is set concave toward the side close to the center of the grating unit 1201 .

[0078] Reference Figure 4 In one embodiment of the present application, the grating unit 1201 includes four concave arc edges 1204, and the four concave arc edges 1204 enclose a quadrilateral. The quadrilateral formed by the four concave arc edges 1204 is symmetrically arranged about the X axis and the Y axis. The grating unit 1201 is arranged as a star curve.

[0079] Of course, the grating unit 1201 may also include three concave arc edges 1204 to form a triangle, five concave arc edges 1204 to form a pentagon, or six concave arc edges 1204 to form a hexagon.

[0080] In the embodiment of the present application, the arc edge includes at least one convex arc edge 1203 and at least one concave arc edge 1204 , wherein when n>1, it is a convex arc edge 1203 , and when n<1, it is a concave arc edge 1204 .

[0081] The arc edge includes at least one convex arc edge 1203 and at least one concave arc edge 1204. When n<1, the arc edge in the super ellipse equation is set as the concave arc edge 1204. That is, the arc edge is set concave toward the side close to the center of the grating unit 1201. When n>1, the arc edge that satisfies the super ellipse equation is set as the convex arc edge 1203. That is, the arc edge is set convex toward the side away from the center of the grating unit 1201.

[0082] Reference Figure 5-Figure 6 In one embodiment of the present application, the grating unit 1201 is formed by arc edges only. The arc edges include, for example, two convex arc edges 1203 and two concave arc edges 1204. The two concave arc edges 1204 and the two convex arc edges 1203 are enclosed to form a quadrilateral.

[0083] The quadrilateral formed by the two concave arc edges 1204 and the two convex arc edges 1203 is, for example, symmetrically arranged about the Y axis, such as Figure 5 shown.

[0084] The quadrilateral formed by the two concave arc edges 1204 and the two convex arc edges 1203 is, for example, symmetrically arranged about the X axis, such as Figure 6 shown.

[0085] In another embodiment of the present application, the grating unit 1201 is formed by an arc edge and a straight edge 1202. The arc edge includes at least one convex arc edge 1203 and at least one concave arc edge 1204, and the straight edge 1202 is provided with at least one.

[0086] Specifically, the grating unit 1201 is formed by a convex arc edge 1203, a concave arc edge 1204 and a straight edge 1202, and the grating unit 1201 is set to an asymmetric triangular structure. The asymmetric structure can reduce the loss of the symmetrical diffraction order part of the light, which is conducive to the multi-directional comprehensive expansion and coupling of the coupled light in the coupling area 120, so that more light is coupled on the human eye side, which can improve the light efficiency utilization rate.

[0087] Of course, the grating unit 1201 may also be configured as a quadrilateral, pentagon, hexagon, etc. The grating unit 1201 may be formed by a convex arc edge 1203 , a concave arc edge 1204 and at least one straight edge 1202 .

[0088] In the embodiment of the present application, the value range of n is: 0.5≤n≤1.5.

[0089] In a preferred embodiment of the present application, the power of the super elliptic equation has a value range of 0.5≤n≤1.5.

[0090] When 0.5≤n<1, the arc edge in the super ellipse equation is set as a concave arc edge 1204. That is, the arc edge is set concave toward the side close to the center of the grating unit 1201.

[0091] When n=1, the arc edge in the super ellipse equation is set as a straight line, and the grating unit 1201 is set as a rhombus.

[0092] When 1<n≤1.5, the arc edge satisfying the super ellipse equation is set as a convex arc edge 1203. That is, the arc edge is convex toward the side away from the center of the grating unit 1201.

[0093] In the grating unit 1201 provided in the present application, the power n of the super ellipse equation is within this range, and the arc has a suitable curvature, so that the grating unit 1201 composed of the arc can evenly disperse the light and improve the uniformity of the outcoupled light.

[0094] In the embodiment of the present application, the grating vector of the coupling-in grating 111 is K1, and the grating vectors of the coupling-out grating 121 are K2 and K3 respectively, and K1, K2 and K3 form a closed vector triangle.

[0095] In the embodiment of the present application, the coupling grating 111 has a grating vector in a direction, which is, for example, a direction perpendicular to the grating lines and is a direction in which the coupling grating 111 changes periodically, and its length is equal to the inverse of the grating period of the coupling grating 111.

[0096] In the present application, by limiting the relationship between the grating vectors of the coupling-in grating 111 and the coupling-out grating 121, it can be ensured that the exit angle of the light during coupling-out is consistent with the incident angle of the light when coupled-in through the coupling-in grating 111, thereby reducing the dispersion of the light during the propagation process, which is beneficial to improving the diffraction efficiency of the light, reducing the waste of light, and improving the clarity of the coupled-out light.

[0097] It should be noted that, in the embodiment of the present application, the number of the outcoupling grating 121 is not limited to one, but may be two or more. Then the sum of the vectors of the incoupling grating 111 and each outcoupling grating 121 should satisfy that the vector sum is zero.

[0098] Reference Figure 7 , when the first diffraction light 1001 is incident on the outcoupling grating 121, it will propagate the second diffraction light 1002 (whose diffraction order is different from that of the first diffraction light 1001) symmetrically to both sides, and couple out the first outgoing light 1003. The second diffraction light 1002 continues to propagate in the waveguide substrate 100 along the original direction. When the second diffraction light 1002 is incident on the right outcoupling grating 121 again, it will generate the third diffraction light 1004 and couple out the second outgoing light 1005. The direction of the third diffraction light 1004 is the same as that of the first diffraction light 1001 ( Figure 7 The first diffraction ray 1001 and the third diffraction ray 1004 will continue to propagate along the original direction in the waveguide substrate 100. When the first diffraction ray 1001 and the third diffraction ray 1004 are incident on the right outcoupling grating 121 again, outcoupling outgoing rays are generated, and each will continue to propagate forward, and the pupil of the light is continuously expanded, so that more light can be coupled out, thereby enabling more light to be coupled into the human eye.

[0099] It should be noted that after the light is pupil-expanded by the outcoupling grating 121 provided in the present application, the outgoing light will cover the outcoupling area viewed by the human eye, thereby expanding the user's viewing angle. Since the grating unit includes at least one arc edge that satisfies the superellipse equation, the outcoupling grating formed by the grating unit can better regulate the distribution of the outcoupling efficiency of the diffraction optical waveguide, which is beneficial to improving the outcoupling effect of the light of the optical waveguide device and the uniformity of the outcoupling light. The display device with such a diffraction optical waveguide has the advantages of high brightness and high uniformity.

[0100] The present application also provides a head-mounted display device, comprising the optical waveguide device as described above.

[0101] For example, the head-mounted display device includes a shell and two optical waveguide devices arranged in the shell, and the two optical waveguide devices can correspond to the left eye and the right eye of the user respectively.

[0102] The head mounted display device of the embodiment of the present application may be, for example, an augmented reality display device, such as AR glasses or an AR helmet.

[0103] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. An optical waveguide device, characterized in that: It comprises a waveguide substrate (100), and an in-coupling region (110) and an out-coupling region (120) arranged on the waveguide substrate (100); The coupling-in region (110) is provided with a coupling-in grating (111) for coupling light into the waveguide substrate (100); The outcoupling region (120) is provided with an outcoupling grating (121), the outcoupling grating (121) comprising a grating array formed by a plurality of grating units (1201), the cross section of each grating unit (1201) being a polygon, the grating unit (1201) comprising at least one arc edge, the arc edge satisfying a superellipse equation Where n, a and b are positive numbers.

2. The optical waveguide device according to claim 1, characterized in that The grating unit (1201) further comprises at least one straight edge (1202), and the arc edge and the straight edge (1202) enclose a polygon.

3. The optical waveguide device according to claim 1, characterized in that The grating unit (1201) comprises two arc edges and two straight edges (1202), and the two arc edges and the two straight edges (1202) enclose a quadrilateral.

4. The optical waveguide device according to claim 1, characterized in that The grating unit includes a plurality of arc edges, and the plurality of arc edges are enclosed to form a polygon.

5. The optical waveguide device according to claim 4, characterized in that: The n>1, the arc edge is set as a convex arc edge (1303), and a plurality of the convex arc edges (1203) are enclosed to form a polygon.

6. The optical waveguide device according to claim 4, characterized in that When n is less than 1, the arc edge is set as a concave arc edge (1204), and a plurality of the concave arc edges (1204) are enclosed to form a polygon.

7. The optical waveguide device according to claim 4, characterized in that The arc edge includes at least one convex arc edge (1203) and at least one concave arc edge (1204), wherein when n>1, it is a convex arc edge (1203), and when n<1, it is a concave arc edge (1204).

8. The optical waveguide device according to claim 1, characterized in that The value range of n is: 0.5≤n≤1.

5.

9. The optical waveguide device according to claim 1, characterized in that The grating vector of the coupling-in grating (111) is K1, and the grating vectors of the coupling-out grating (121) are K2 and K3 respectively, and K1, K2 and K3 form a closed vector triangle.

10. A head mounted display device, characterized in that: The optical waveguide device comprises the optical waveguide device according to any one of claims 1 to 9.

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