Film coating method of light guide device, light guide device and head-mounted display equipment

Abstract

The embodiment of the invention provides a coating method of a light guide device, the light guide device and head-mounted display equipment. The film coating method of the light guide device comprises the following steps: providing a substrate, and forming a coupling-in area and a coupling-out area on the substrate; forming a metal layer on the coupling-in region under the condition that the coupling-out region is shielded, and controlling the thickness of the metal layer to be greater than 15nm; and forming a non-metal material layer on the substrate under the condition that the coupling-in area is not shielded, and the non-metal material layer at least covers the coupling-out area.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of optical imaging technology. More specifically, the embodiments of the present application relate to a coating method for a light guide device, a light guide device and a head-mounted display device. Background Art

[0002] Augmented reality (AR) is a technology that combines virtual information with the real world. The diffraction waveguide solution is considered to be the best optical display solution in augmented reality technology. The diffraction waveguide solution often requires separate area coating. For example, the material type and thickness of the coating layer in the coupling-in area and the coupling-out area are different. Therefore, in the process, it is necessary to mask one area first and then mask the other area to deposit the film layer. Summary of the invention

[0003] The purpose of this application is to provide a coating method for a light guide device, a light guide device, and a new technical solution for a head-mounted display device.

[0004] In a first aspect, the present application provides a coating method for a light guide device. The coating method for a light guide device comprises:

[0005] Providing a substrate, and forming a coupling-in region and a coupling-out region on the substrate;

[0006] Under the condition of shielding the out-coupling region, forming a metal layer on the in-coupling region, and controlling the thickness of the metal layer to be greater than 15 nm; and

[0007] A non-metal material layer is formed on the substrate without shielding the coupling-in region, and the non-metal material layer at least covers the coupling-out region.

[0008] Optionally, the coupling-in region includes a coupling-in grating, and the structure of the metal layer corresponds to the structure of the coupling-in grating.

[0009] Optionally, the thickness of the metal layer is H, and 16nm≤H≤100nm.

[0010] Optionally, the material of the metal layer includes aluminum, gold, copper or silver.

[0011] Optionally, the metal layer is also covered with the non-metal material layer;

[0012] The out-coupling region includes an out-coupling grating and the non-metal material layer covering the out-coupling grating, and the in-coupling grating and the out-coupling grating form a closed grating vector polygon.

[0013] Optionally, the metal layer is formed in the coupling-in region by a deposition method, wherein the deposition method includes atomic layer deposition ALD, physical vapor deposition PVD, high temperature gas phase reaction CVD or plasma enhanced chemical vapor deposition PECVD.

[0014] Optionally, the non-metal material layer is made of silicon oxide, titanium oxide, aluminum oxide or embossing glue.

[0015] In a second aspect, an embodiment of the present application provides a light guide device, which is manufactured using the coating method of the light guide device as described in the first aspect.

[0016] In a third aspect, an embodiment of the present application provides a light guide device, the light guide device comprising a substrate, and an incoupling region and an outcoupling region disposed on the substrate;

[0017] The coupling-in region is at least covered with a metal layer;

[0018] The outcoupling region is covered with a non-metallic material layer.

[0019] In a fourth aspect, an embodiment of the present application provides a head-mounted display device, the head-mounted display device comprising:

[0020] a housing; and

[0021] The light guiding device as described in the second aspect or the third aspect.

[0022] The beneficial effects of this application are:

[0023] According to the coating method of the light-guiding device provided in the embodiment of the present application, by first forming a metal layer of a certain thickness in the coupling-in region, when forming a non-metallic material layer in the coupling-out region, the coupling-in region does not need to be shielded. This is because the metal material has a skin effect. After exceeding its skin depth, the metal layer with excess thickness will no longer affect the diffraction behavior of the coupling-in region. The design of the metal layer makes it unnecessary to shield the coupling-in region when forming a non-metallic material layer on the coupling-out region, thereby effectively reducing the number of steps and lowering the production cost.

[0024] Other features and advantages of the present specification will become apparent from the following detailed description of exemplary embodiments of the present specification with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.

[0026] Figure 1 A schematic diagram of the structure of a light guide device provided in an embodiment of the present application;

[0027] Figure 2 A schematic diagram of forming a metal layer on a coupling-in region provided in an embodiment of the present application;

[0028] Figure 3 for Figure 2 Diffraction efficiency curve of the metal layer shown in;

[0029] Figure 4 For Figure 2 Schematic diagram of forming a non-metallic material layer on a metal layer in FIG.

[0030] Figure 5 for Figure 4 Diffraction efficiency curve of a non-metallic material layer covered on a metal layer shown in FIG.

[0031] Figure 6 A schematic diagram of covering a silicon oxide layer on the coupling-in region of a light-guiding device;

[0032] Figure 7 for Figure 6 Diffraction efficiency curve of the coupling-in region shown in;

[0033] Figure 8 A schematic diagram of stacking a titanium oxide layer and a silicon oxide layer in the coupling-in region of a light guide device;

[0034] Fig. 9 for Figure 8 Diffraction efficiency curve of the coupling-in region is shown in FIG.

[0035] Description of reference numerals:

[0036] 100, substrate; 101, coupling-in region; 102, coupling-out region; 200, metal layer; 300, non-metal material layer; 400, titanium oxide layer; 500, silicon oxide layer. DETAILED DESCRIPTION

[0037] 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.

[0038] 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.

[0039] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

[0040] 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.

[0041] 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.

[0042] The coating method of the light guide device, the light guide device and the head mounted display device provided in the embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0043] According to one aspect of an embodiment of the present application, a coating method for a light-guiding device is provided. The light-guiding device finally produced is, for example, a diffraction light waveguide element, which can be applied to AR optical solutions. The coupling-in region and the coupling-out region of the light-guiding device are both formed with a set film layer.

[0044] It should be noted that the conventional coating method of the diffractive optical waveguide element is to mask the out-coupling area after the coupling-in area and the out-coupling area of ​​the diffractive optical waveguide element are manufactured, and then mask the coupling-in area to form a metal oxide layer on the coupling-in area, and then mask the coupling-in area to form a non-metal oxide layer on the out-coupling area. The whole process involves two masking steps, and the reason for this design is that the coupling-in area and the out-coupling area have different requirements for the light diffraction behavior, and the coatings formed are also different.

[0045] The method for manufacturing a light guide device provided in an embodiment of the present application comprises the following steps:

[0046] Step S1, providing a substrate 100, and forming a coupling-in region 101 and a coupling-out region 102 on the substrate 100, see Figure 1 ;

[0047] Step S2: Under the condition of shielding the out-coupling region 102, a metal layer 200 is formed on the in-coupling region 101, and the thickness of the metal layer 200 is controlled to be greater than 15 nm, see Figure 2 ;as well as

[0048] Step S3 : forming a non-metal material layer 300 on the substrate 100 without shielding the coupling-in region 101 , and the non-metal material layer 300 at least covers the coupling-out region 102 .

[0049] According to the coating method of the light guide device provided in the above embodiment of the present application, by first forming a metal layer 200 of a certain thickness at the position of the coupling-in region 101, when the non-metal material layer 300 is formed at the position of the coupling-out region 102, the coupling-in region 101 may not be shielded. This is because metal materials have a skin effect. After exceeding its skin depth, the excess thickness of the metal layer 200 will no longer affect the diffraction behavior (diffraction efficiency) of the coupling-in region 101. The design of the metal layer 200 makes it unnecessary to shield the coupling-in region 101 when the non-metal material layer 300 is formed on the coupling-out region 102, which effectively reduces the number of processes and reduces the production cost.

[0050] That is to say, compared with the traditional diffraction waveguide coating solution, the manufacturing solution provided in the embodiment of the present application does not require the separation area coating operation.

[0051] The scheme provided by the embodiment of the present application can omit the shielding step. The coupling region 101 is formed with a metal layer 200. Based on the skin effect of the metal material, even if a non-metal material layer 300 is formed on the metal layer 200, the diffraction efficiency will not be affected, that is, the diffraction efficiency requirement for the coupling region 101 can be guaranteed, thereby ensuring the optical performance of the light guide device and improving the imaging quality.

[0052] In the step S1, the coupling-in region 101 and the coupling-out region 102 may be arranged in any arrangement or combination on the same surface of the substrate 100. Of course, the coupling-in region 101 and the coupling-out region 102 may also be located on different surfaces of the substrate 100.

[0053] The coupling-in region 101 includes a coupling-in grating.

[0054] The coupling-in grating may be any type of one-dimensional grating or any type of two-dimensional grating. For example, the coupling-in grating in the coupling-in region 101 is a blazed grating.

[0055] The outcoupling region 102 includes an outcoupling grating.

[0056] The outcoupling grating may be any type of one-dimensional grating or any type of two-dimensional grating.

[0057] In step S2, the thickness of the metal layer 200 is designed to be greater than the skin depth of visible light in the metal layer 200, so that after exceeding its skin depth, the excess thickness of the metal layer 200 will no longer affect the diffraction behavior of the coupling grating in the coupling region 101 to visible light.

[0058] Specifically, see Figure 2As shown, a metal layer 200 with a thickness greater than 15 nm is first formed on the coupling region 101. At this time, based on the skin effect of the material, the diffraction efficiency curve of the coupling region 101 can be seen in FIG. Figure 3 .

[0059] In the step S3, based on the fact that the metal layer 200 having a thickness greater than 15 nm has been formed on the coupling-in region 101 in the step S2, at this time, the non-metal material layer 300 covering the coupling-out region 102 can be directly formed on the substrate 100 without shielding the coupling-in region 101. That is, when the non-metal material layer on the coupling-out region 102 is formed, the process of shielding the coupling-in region 101 can be omitted, that is, the non-metal material layer 300 can be directly formed on the substrate 100 without avoiding the coupling-in region 101, which can simplify the process.

[0060] In the step S3, since the coupling-in region 101 is not shielded, the non-metal material layer 300 is directly formed on the substrate 100. At this time, the non-metal material layer 300 not only covers the designated coupling-out region 102, but also covers the unshielded coupling-in region 101. Figure 4 At this time, the non-metal material layer 300 formed on the coupling region 101 is stacked on the metal layer 200 of a certain thickness. Based on the skin effect of the metal material, when the incident light diffracts in the coupling region 101, the efficiency curve of the coupling region 101 is as follows: Figure 5 As shown, it is Figure 3 Comparison of the diffraction efficiency curves shown shows that the results of the two have not changed, which indicates that the introduction of the metal layer 200 does not affect the diffraction performance of the coupling-in region 101 even if a non-metal material layer 300 is superimposed thereon.

[0061] See also Figure 6 , Figure 6 The coating scheme of the conventional light guide device is shown. An input region 101 is formed on a substrate 100. A metal oxide layer is formed on the input region 101. The metal oxide layer is, for example, a titanium oxide layer 400. At this time, the change trend of the diffraction efficiency curve corresponding to the input region 101 can be seen in FIG. Figure 7 On this basis, if the coupling-in region 101 is not shielded, and a non-metal material layer 300 is directly formed on the coupling-out region 102, for example, the non-metal material layer 300 is a silicon oxide layer 500, see Figure 8 At this time, the diffraction efficiency curve corresponding to the coupling region 101 (with Figure 7 The diffraction efficiency curve shown in Figure 1 is significantly affected, and the overall efficiency is reduced. Fig. 9 .

[0062] It should be noted that, in the embodiment of the present application, the non-metal material layer 300 may be formed on the substrate 100 by means of coating, and the non-metal material layer 300 may cover the out-coupling region 102 .

[0063] In some examples of this application, see Figure 2 The coupling region 101 includes a coupling grating, and the structure of the metal layer 200 corresponds to the structure of the coupling grating.

[0064] For example, the coupling grating used in the coupling region 101 is a blazed grating, see Figure 2 , the shape of the metal layer 200 needs to correspond to the structural shape of the blazed grating.

[0065] In order to better integrate the metal layer 200 with the coupling grating, the structural shape of the metal layer 200 should be matched with the structural shape of the coupling grating.

[0066] It should be noted that Figure 2 The coupling grating is not shown in the figure, and only the structural shape of the blazed grating is used as an example to illustrate the structural form of the metal layer 200. That is, a blazed grating is used as the coupling region, and the metal layer 200 is deposited on its surface.

[0067] In some examples of the present application, the thickness of the metal layer 200 is H, and 16nm≤H≤100nm.

[0068] The coating solution provided in the embodiment of the present application mainly forms a metal layer 200 of a certain thickness at the position of the coupling region 101 to prevent the non-metallic oxide coating formed subsequently from affecting the diffraction efficiency of the coupling region 101. The skin effect of the metal material is used, which has requirements for the thickness of the metal layer formed by the metal material. Only when the skin depth is exceeded, the excess thickness of the metal layer will no longer affect the diffraction behavior of the coupling region.

[0069] The thickness of the metal layer 200 of the coupling region 101 is usually 16 nm to 100 nm. The thickness of the metal layer is easy to control and process, and will not cause the thickness of the light guide device to be too large.

[0070] For example, the thickness of the metal layer 200 can be designed to be 16 nm, 25 nm, 40 nm, 60 nm, 95 nm, etc. The thickness of the metal layer 200 can be flexibly controlled as needed, and this application does not impose any limitation on this.

[0071] In some examples of the present application, the material of the metal layer 200 includes aluminum, gold, copper or silver.

[0072] Among the materials of the metal layer 200 provided in the above examples, aluminum is more preferably used.

[0073] All of the above-mentioned metal materials have skin effect, and can be selected according to needs and costs in practical applications, which is not limited in this application.

[0074] In some examples of the present application, the metal layer 200 is further covered with the non-metal material layer 300, see Figure 3 The out-coupling region 102 includes an out-coupling grating and the non-metallic material layer 300 covering the out-coupling grating, and the in-coupling grating and the out-coupling grating form a closed grating vector polygon.

[0075] Based on the above example, see Figure 3 The coupling-in region 101 includes a metal layer 200 and a non-metal material layer 300 stacked on the coupling-in grating. The coupling-out region 102 includes a non-metal material layer 300 stacked on the coupling-out grating. The coupling-in region 101 and the non-metal material layer 300 on the coupling-out region 102 can be formed by coating on the substrate 100.

[0076] See also Figure 1 In the light-guiding device provided in the embodiment of the present application, the substrate 100 has an incoupling region 101 and an outcoupling region 102. The incoupling region 101 is used to couple external light into the substrate 100. The outcoupling region 102 can have the function of pupil expansion and outcoupling, and can expand the incoupling light from the incoupling region 101 in both horizontal and vertical dimensions and couple the light out.

[0077] The coupling-in grating of the coupling-in region 101 and the coupling-out grating of the coupling-out region 102 need to form a closed grating vector polygon.

[0078] Optionally, the coupling region 101 may be composed of a single one-dimensional or two-dimensional grating or a plurality of one-dimensional or two-dimensional gratings.

[0079] Optionally, the outcoupling region 102 may be composed of a single two-dimensional grating or a plurality of one-dimensional or two-dimensional gratings.

[0080] In some examples of the present application, the metal layer 200 can be formed in the coupling region 101 by a deposition method, and the deposition method includes atomic layer deposition ALD, physical vapor deposition PVD, high temperature gas phase reaction CVD or plasma enhanced chemical vapor deposition PECVD.

[0081] The formation method of the metal layer 200 provided in the above example is conducive to controlling the thickness of the metal layer 200 to be greater than 15 nm.

[0082] In some examples of the present application, the material of the non-metal material layer 300 includes silicon oxide, titanium oxide, aluminum oxide or embossing glue.

[0083] According to another aspect of the present application, a light guide device is provided, which is manufactured using the coating method of the light guide device as described above.

[0084] According to another aspect of the present application, a light guide device is also provided. Figure 1 The light guide device includes a substrate 100, and a coupling-in region 101 and a coupling-out region 102 arranged on the substrate 100; the coupling-in region 101 is at least covered with a metal layer 200; and the coupling-out region 102 is covered with a non-metal material layer 300.

[0085] The light guide device is, for example, a diffractive light waveguide element, and the substrate 100 is a waveguide substrate.

[0086] The coupling-in region 101 is used to couple external light into the substrate 100 .

[0087] The out-coupling region 102 is a pupil expansion and out-coupling grating, which expands the coupled light from the coupling region 101 in two dimensions, horizontally and vertically, and couples the light out.

[0088] The coupling-in region 101 and the coupling-out region 102 may be placed on the same surface of the substrate 100 or distributed on different surfaces in any arrangement or combination.

[0089] For the entire light-guiding device, the coupling-in grating in the coupling-in region 101 and the coupling-out grating in the coupling-out region 102 form a closed grating vector polygon. The coupling-in region 101 can be composed of a single one-dimensional or two-dimensional grating or a plurality of one-dimensional or two-dimensional gratings. The coupling-out region 102 can be composed of a single two-dimensional grating or a plurality of one-dimensional or two-dimensional gratings.

[0090] According to another aspect of the present application, an embodiment of the present application further provides a head mounted display device, wherein the head mounted display device comprises a housing and the light guide device as described above.

[0091] The light guide device is, for example, a diffractive light waveguide element, which is disposed in the housing.

[0092] In an embodiment of the present application, the head-mounted display device may be AR glasses or MR glasses, which also includes an image source, which provides incident light for the light guide device. When the incident light is incident from the air medium to the light guide device, it first passes through the diffraction of the coupling-in area 101, then enters the substrate 100, is transmitted through total reflection, and then passes through the coupling-out area 102 and enters the human eye.

[0093] The specific implementation of the head-mounted display device of the embodiment of the present application can refer to the coating method of the above-mentioned light guide device and the various embodiments of the light guide device. Therefore, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0094] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0095] 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. A coating method for a light guide device, characterized in that: include: Providing a substrate, and forming a coupling-in region and a coupling-out region on the substrate; Under the condition of shielding the out-coupling region, forming a metal layer on the in-coupling region, and controlling the thickness of the metal layer to be greater than 15 nm; and A non-metal material layer is formed on the substrate without shielding the coupling-in region, and the non-metal material layer at least covers the coupling-out region.

2. The coating method of a light guide device according to claim 1, characterized in that: The coupling-in region includes a coupling-in grating, and the structure of the metal layer corresponds to the structure of the coupling-in grating.

3. The coating method of a light guide device according to claim 1, characterized in that: The thickness of the metal layer is H, and 16nm≤H≤100nm.

4. The coating method of a light guide device according to claim 1, characterized in that: The material of the metal layer includes aluminum, gold, copper or silver.

5. The coating method of a light guide device according to claim 2, characterized in that: The metal layer is also covered with the non-metal material layer; The out-coupling region includes an out-coupling grating and the non-metal material layer covering the out-coupling grating, and the in-coupling grating and the out-coupling grating form a closed grating vector polygon.

6. The coating method for a light guide device according to any one of claims 1 to 5, characterized in that: The metal layer is formed in the coupling-in region by a deposition method, wherein the deposition method includes atomic layer deposition ALD, physical vapor deposition PVD, high temperature gas phase reaction CVD or plasma enhanced chemical vapor deposition PECVD.

7. The coating method of a light guide device according to claim 1, characterized in that: The material of the non-metal material layer includes silicon oxide, titanium oxide, aluminum oxide or embossing glue.

8. A light guide device, characterized in that: The light guide device is manufactured by the coating method of any one of claims 1 to 7.

9. A light guide device, characterized in that: It comprises a substrate (100), and a coupling-in region (101) and a coupling-out region (102) arranged on the substrate (100); The coupling region (101) is at least covered with a metal layer (200); The outcoupling region (102) is covered with a non-metal material layer (300).

10. A head mounted display device, characterized in that: include: a housing; and A light guiding device as claimed in claim 8 or 9.

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