Optical waveguide device and near-eye display device

Abstract

The embodiments of the present invention provide an optical waveguide device and a near-eye display device, which relate to the field of optical technology. The optical waveguide device provided by the embodiments of the present invention includes a waveguide plate, the waveguide plate includes a coupling-in region and a coupling-out region, the thickness of the coupling-in region is greater than the thickness of the coupling-out region; the coupling-in region includes a coupling-in surface located on the side wall of the waveguide plate, and the coupling-out region includes a plurality of parallel coupling-out splitting surfaces, the angle between the coupling-in surface and the first direction is greater than or equal to 68° and less than or equal to 76°, the angle between the coupling-out splitting surface and the first direction is greater than or equal to 34° and less than or equal to 38°, the first direction is parallel to the light-emitting surface of the waveguide plate, and points from the coupling-in region to one side of the coupling-out region. The optical waveguide device and the near-eye display device provided by the embodiments of the present invention improve the display effect of the display screen output by the optical waveguide device and reduce the manufacturing cost of the optical waveguide device.

Description

Technical Field

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

[0002] Augmented Reality (AR) optical waveguide is an optical device used in AR near-eye display devices. It can project virtual images directly into the user's eyes while ensuring that the user's view of the real world is not blocked. AR optical waveguide products have problems with blue arc and mirror stray light, which leads to the limitation of the field of view of the array optical waveguide in the out-coupling pupil expansion direction. Summary of the invention

[0003] The embodiments of the present invention provide an optical waveguide device and a near-eye display device. The optical waveguide device can solve the display problems of the existing array optical waveguide, such as blue arc, mirror stray light, external reflected stray light, and limited field of view, improve the display effect of the display screen output by the optical waveguide device, and reduce the manufacturing cost of the optical waveguide device.

[0004] In a first aspect, an embodiment of the present invention provides an optical waveguide device, including a waveguide plate, the waveguide plate including a coupling-in region and a coupling-out region, the thickness of the coupling-in region is greater than the thickness of the coupling-out region; The light-emitting surface of the waveguide plate is a first plane, and the waveguide plate further comprises a second plane opposite to the first plane, the coupling-in region and the coupling-out region are flush on one side of the second plane, and the coupling-in region bulges toward a side away from the second plane; The coupling-in region includes a coupling-in surface located on the side wall of the waveguide plate, and the out-coupling region includes a plurality of parallel out-coupling splitting surfaces, the angle between the coupling-in surface and the first direction is greater than or equal to 68° and less than or equal to 76°, the angle between the out-coupling splitting surface and the first direction is greater than or equal to 34° and less than or equal to 38°, the first direction is parallel to the light emitting surface of the waveguide plate, and points from the coupling-in region to one side of the out-coupling region.

[0005] Optionally, the incident light is incident into the waveguide plate from the coupling-in surface, and after being totally reflected and transmitted in the waveguide plate, is coupled out to the human eye from the multiple coupling-out splitting surfaces.

[0006] Optionally, when incident light rays of different fields of view are incident from the coupling-in surface into the waveguide plate and are transmitted through total reflection in the waveguide plate, the light rays are connected end to end.

[0007] Optionally, the optical waveguide device further comprises a dielectric layer disposed on two surfaces of the waveguide plate, and a refractive index of the dielectric layer is smaller than a refractive index of the waveguide plate.

[0008] In a second aspect, an embodiment of the present invention provides an optical waveguide device, including a waveguide plate, the waveguide plate including a coupling-in region and a coupling-out region, the thickness of the coupling-in region is greater than the thickness of the coupling-out region, the coupling-in region and the coupling-out region are flush on one side of a light-emitting surface of the waveguide plate, and the coupling-in region is convex toward a side away from the light-emitting surface of the waveguide plate; The coupling-in region includes a coupling-in reflection surface located on the side wall of the waveguide plate or inside the waveguide plate, and the coupling-out region includes a plurality of parallel coupling-out splitting surfaces, the angle between the coupling-in reflection surface and the first direction is greater than or equal to 34° and less than or equal to 38°, the angle between the coupling-out splitting surface and the second direction is greater than or equal to 34° and less than or equal to 38°, the first direction and the second direction are both parallel to the light emitting surface of the waveguide plate, the first direction points from the coupling-in region to one side of the coupling-out region, and the second direction points from the coupling-out region to one side of the coupling-in region.

[0009] Optionally, the incident light is incident from the light emitting surface side of the waveguide plate, is reflected by the coupling-in reflection surface, is transmitted by total reflection in the waveguide plate, and is coupled out to the human eye from multiple coupling-out splitting surfaces.

[0010] Optionally, incident light of different fields of view is incident from one side of the light emitting surface of the waveguide, and after being reflected by the coupling reflection surface, the light is transmitted by total reflection in the waveguide, and the light is connected end to end.

[0011] Optionally, the optical waveguide device further comprises a dielectric layer disposed on two surfaces of the waveguide plate, and a refractive index of the dielectric layer is smaller than a refractive index of the waveguide plate.

[0012] In a third aspect, an embodiment of the present invention provides an optical waveguide device, including a waveguide plate, wherein the waveguide plate includes a first surface and a second surface arranged in parallel; The waveguide plate includes a coupling-in region and a coupling-out region, the coupling-in region includes a plurality of coupling-in splitting surfaces arranged in parallel, the coupling-out region includes a plurality of coupling-out splitting surfaces arranged in parallel, the angle between the coupling-in splitting surface and the first direction is greater than or equal to 34° and less than or equal to 38°, the angle between the coupling-out splitting surface and the second direction is greater than or equal to 34° and less than or equal to 38°, the first direction and the second direction are both parallel to the second surface, the first direction points from the coupling-in region to one side of the coupling-out region, and the second direction points from the out-coupling region to one side of the coupling-in region.

[0013] Optionally, the incident light is incident from the second surface, reflected by the multiple coupling-in splitting surfaces, and after total reflection transmission in the waveguide plate, coupled out from the multiple coupling-out splitting surfaces to the human eye.

[0014] Optionally, the optical waveguide device further includes a dielectric layer disposed on the first surface and the second surface, and the refractive index of the dielectric layer is smaller than the refractive index of the waveguide plate.

[0015] In a fourth aspect, an embodiment of the present invention provides a near-eye display device, comprising an optical machine and an optical waveguide device provided by any embodiment of the present invention.

[0016] The optical waveguide device provided by the embodiment of the present invention changes the propagation path of the light in the waveguide plate by adjusting the structures of the coupling-in region and the coupling-out region, thereby increasing the exit angle of the central field coupling-out light of the left and right mirror stray light and the blue arc on the light-emitting surface of the waveguide plate, avoiding the left and right mirror stray light and the blue arc from entering the human eye, and improving the display effect of the display picture output by the optical waveguide device; at the same time, the refractive index of the waveguide plate is greater than or equal to 1.52, which can eliminate the left and right mirror stray light and the blue arc, and the conventional glass with a refractive index of 1.52 is relatively low in cost, thereby reducing the manufacturing cost of the optical waveguide device; in addition, the optical waveguide device optimizes the working angle range of the coupling-out beam splitter surface, reduces the design difficulty of the film system of the coupling-out beam splitter surface, weakens the intensity of the external reflected stray light entering the eye, and improves the display effect of the display picture output by the optical waveguide device.

[0017] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution in this embodiment, the drawings required for use in the description of the embodiment will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the positions of the left image stray light, right image stray light, blue arc and display screen of the optical waveguide; Figure 2 It is a light path diagram of light generated by the optical waveguide of the prior art for right-mirror stray light; Figure 3 It is a light path diagram of the light of left-mirror stray light generated by the optical waveguide of the prior art; Figure 4 It is a light path diagram of stray light reflected from the outside in the optical waveguide of the prior art; Figure 5 is a schematic structural diagram of an optical waveguide device provided by an embodiment of the present invention; Figure 6 is a light path diagram of right mirror image stray light in a waveguide provided by an embodiment of the present invention; Figure 7 is a light path diagram of left mirror stray light in a waveguide provided by an embodiment of the present invention; Figure 8 is a light path diagram of stray light reflected from the outside in a waveguide provided by an embodiment of the present invention; Fig. 9It is a relationship diagram between the reflectivity of the film system of the out-coupling splitter surface and the incident angle in the prior art; Fig.10 is a graph showing the relationship between the reflectivity of the film system of the out-coupling beam splitter surface and the incident angle provided by an embodiment of the present invention; Fig.11 is a light path diagram of incident light propagating in a waveguide provided by an embodiment of the present invention; Fig.12 is a light path diagram of incident light rays of different viewing fields coupled into a waveguide provided by an embodiment of the present invention; Fig.13 It is the optical path diagram of incident light at different angles propagating in a waveguide without a protruding structure; Fig.14 is a schematic structural diagram of another optical waveguide device provided by an embodiment of the present invention; Fig.15 is a light path diagram of incident light propagating in another waveguide provided by an embodiment of the present invention; Fig.16 is a light path diagram of incident light of different fields of view propagating in another waveguide sheet provided by an embodiment of the present invention; Fig.17 is a schematic structural diagram of another optical waveguide device provided by an embodiment of the present invention; Fig.18 is a light path diagram of incident light propagating in another waveguide provided by an embodiment of the present invention; Fig.19 It is a schematic diagram of the structure of a two-dimensional array waveguide provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the present solution, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only 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 should fall within the scope of protection of the present invention.

[0021] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0022] The optical waveguide in the prior art has the problems of left mirror stray light, right mirror stray light, blue arc and external reflected stray light, resulting in poor imaging quality. In order to prevent the left mirror stray light, right mirror stray light, blue arc and external reflected stray light from entering the human eye, it is necessary to prevent the above stray light from entering the human eye range. Assuming the lateral field of view angle is 2α0, the maximum eye movement length in the pupil expansion direction is H, the exit pupil distance is D, and the pupil diameter of the human eye is generally 4mm, in order to prevent the stray light emitted from the optical waveguide from entering the human eye, the angle α between the stray light emitted from the optical waveguide and the normal of the light emitting surface of the optical waveguide is 杂光 Should meet: .

[0023] For example, assuming that the horizontal field of view of the human eye is 30°, that is, α0 is 15°, D is 18 mm, and H is 8 mm, then the above formula can be used to obtain α 杂光 >39.5°. That is, when α 杂光 When the angle is >39.5°, the stray light emitted from the light waveguide does not enter the human eye.

[0024] Next, the reasons why left-mirror stray light, right-mirror stray light, blue arc and external reflected stray light appear in the optical waveguide of the prior art are introduced respectively. Figure 1 This is a schematic diagram of the positions of the left mirror stray light, right mirror stray light, blue arc and display screen of the optical waveguide. Figure 2 This is the optical path diagram of the light waveguide in the prior art that produces the right mirror image stray light, combined with Figure 1 and Figure 2 As shown, the right mirror stray light is symmetrical with the display screen, so the central field light of the right edge of the display screen corresponds to the central field light of the left edge of the right mirror stray light. Assuming that the normal angle between the light S1 propagated by total reflection in the optical waveguide and the light waveguide light-emitting surface 110' is θ, the incident angle of the central field coupled light S2 of the right edge of the display screen at the light waveguide light-emitting surface 110' is β, and the exit angle of the central field coupled light S2 of the right edge of the display screen at the light waveguide light-emitting surface 110' is α 右, the angle between the light S3 and the out-coupling beam splitter surface 201' is η, the angle between the out-coupling beam splitter surface 201' and the waveguide outgoing surface 110' is δ, the angle between the light S4 and the normal of the waveguide outgoing surface is θ2, the incident angle of the left edge center field out-coupling light S5 of the right mirror stray light at the waveguide outgoing surface 110' is β2, the exit angle of the left edge center field out-coupling light S5 of the right mirror stray light at the waveguide outgoing surface 110' is α1, the angle between the out-coupling beam splitter surface and the waveguide outgoing surface is δ, and the refractive index of the optical waveguide is n, then there is the following relationship: , , , , , , In summary, the relationship between α1 and α can be obtained: .

[0025] Figure 3 This is the optical path diagram of the light generated by the optical waveguide of the prior art, combined with Figure 1 and Figure 3 As shown, the left mirror stray light is symmetrical with the display screen, so the left edge center field light of the display screen corresponds to the right edge center field light of the left mirror stray light, assuming that the normal angle between the light S6 propagated by total reflection in the optical waveguide and the waveguide light-emitting surface 110' is θ, the incident angle of the left edge center field coupled light S7 of the display screen on the waveguide light-emitting surface 110' is β, and the exit angle of the left edge center field coupled light S7 of the display screen on the waveguide light-emitting surface 110' is α 左 , the angle between the light S8 and the out-coupling beam splitter surface 201' is η, the angle between the out-coupling beam splitter surface 201' and the waveguide outgoing surface 110' is δ, the angle between the light S9 and the normal of the waveguide outgoing surface is θ2, the incident angle of the right edge central field out-coupling light S10 of the left mirror stray light at the waveguide outgoing surface 110' is β2, the exit angle of the right edge central field out-coupling light S10 of the left mirror stray light at the waveguide outgoing surface 110' is α2, the angle between the out-coupling beam splitter surface and the waveguide outgoing surface is δ, and the refractive index of the optical waveguide is n, then there is the following relationship: , , , , , , In summary, the relationship between α2 and α can be obtained: .

[0026] The blue arc is caused by the stray bottom light propagating in the optical waveguide. When part of the stray bottom light cannot be totally reflected in the optical waveguide, it cannot enter the human eye. Since the refractive index of the waveguide corresponding to red light is lower than that of blue light, the critical angle of total reflection of red light in the stray bottom light is the smallest, followed by green light, while the critical angle of total reflection of blue light is the largest. Therefore, the red light disappears first at the critical point, followed by green light, and finally blue light. Therefore, the blue arc actually looks like two narrow arc bands composed of blue and cyan. Let the central field angle of the blue arc be α 蓝弧 , we can get α 蓝弧 The expression is: .

[0027] It can be seen from the above formula that the central field angle of the blue arc is only related to the angle of the outcoupling splitter surface and the refractive index of the optical waveguide. The higher the refractive index of the optical waveguide, the larger the central field angle of the blue arc, and the farther the blue arc is from the normal display screen.

[0028] It is understandable that half of the maximum field of view supported by the pupil expansion direction of the outcoupling beam splitter surface cannot exceed the exit angles α1 and α2 of the left and right mirror stray lights, otherwise the field of view will contain the left and right mirror stray lights. Therefore, when the exit angles α1 and α2 of the left and right mirror stray lights are equal, the maximum field of view supported by the pupil expansion direction is the largest. Exemplarily, α1 and α2 are equal, where the exit angles of the outcoupling light from the center field of view of the left and right edges of the display screen should be equal, that is, α 左 =α 右 , the calculation shows that the out-coupling beam splitter angle δ is about 25.7︒. When the refractive index of the optical waveguide n=2, the maximum field of view supported by the pupil expansion direction of the out-coupling beam splitter is about 52.9︒, while α1 and α2 are 38.8︒, which does not meet α 杂光 >39.5°, so the stray light from the left and right mirrors will enter the human eye, resulting in a decrease in display effect.

[0029] In addition, the optical waveguide in the prior art also has the problem of external reflected stray light. Figure 4 This is the optical path diagram of the external reflected stray light in the optical waveguide of the prior art, refer to Figure 4 , Figure 4 The middle dotted line is the propagation path of external reflected stray light. After the external light is refracted from the surface of the optical waveguide into the optical waveguide, it is reflected at the out-coupling splitting surface 201 ′ and then coupled out of the optical waveguide to form external reflected stray light.

[0030] In order to solve the problem that the left image stray light, the right image stray light, the blue arc and the external reflected stray light are reflected by the optical waveguide and enter the human eye, resulting in poor imaging quality, an embodiment of the present invention provides an optical waveguide device, Figure 5 is a schematic diagram of the structure of an optical waveguide device provided by an embodiment of the present invention, with reference to Figure 5 The optical waveguide device includes a waveguide plate, the waveguide plate includes a coupling-in region 100 and a coupling-out region 200, the thickness of the coupling-in region 100 is greater than the thickness of the coupling-out region 200; the light-emitting surface 110 of the waveguide plate is a first plane, the waveguide plate also includes a second plane 120 opposite to the first plane, the coupling-in region 100 and the coupling-out region 200 are flush on one side of the second plane 120, and the coupling-in region 100 bulges toward a side away from the second plane 120; the coupling-in region 100 includes a coupling-in surface 101 located on a side wall of the waveguide plate, the coupling-out region 200 includes a plurality of parallel coupling-out splitting surfaces 201, the angle between the coupling-in surface 101 and the first direction X is greater than or equal to 68° and less than or equal to 76°, the angle between the coupling-out splitting surface 201 and the first direction X is greater than or equal to 34° and less than or equal to 38°, the first direction X is parallel to the light-emitting surface 110 of the waveguide plate, and points from the coupling-in region 100 to the coupling-out region 200.

[0031] Figure 6 is a light path diagram of the right mirror image stray light in the waveguide provided by an embodiment of the present invention, combined with Figure 2 , Figure 5 and Figure 6 As shown, the propagation path of the light in the waveguide provided by the embodiment of the present invention is different from the propagation path of the waveguide in the prior art. Assume that the angle between the light S11 totally reflected in the waveguide and the normal of the light emitting surface 110 of the waveguide is θ, the incident angle of the coupled light S12 at the center of the right edge of the display screen at the light emitting surface 110 of the waveguide is β, and the exit angle of the coupled light S12 at the center of the right edge of the display screen at the light emitting surface 110 of the waveguide is α 右 , the angle between the outcoupling beam splitter 201 and the light-emitting surface 110 of the waveguide is δ, the angle between the outcoupling beam S13 at the left edge of the center field of view of the right mirror stray light and the outcoupling beam splitter 201 is η, the incident angle of the outcoupling beam S13 at the left edge of the center field of view of the right mirror stray light on the light-emitting surface 110 of the waveguide is β2, the exit angle of the outcoupling beam S13 at the left edge of the center field of view of the right mirror stray light on the light-emitting surface 110 of the waveguide is α1, and the refractive index of the waveguide is n, and the following relationship can be obtained: , , , , , In summary, the relationship between α1 and α can be obtained: .

[0032] Figure 7is a light path diagram of the left mirror stray light in the waveguide provided by the embodiment of the present invention, combined with Figure 3 and Figure 7 As shown, the propagation path of the light in the waveguide provided by the embodiment of the present invention is different from the propagation path of the waveguide in the prior art. Assume that the angle between the light S14 totally reflected in the waveguide and the normal of the light emitting surface 110 of the waveguide is θ, the incident angle of the coupled light S15 at the center of the left edge of the display screen at the light emitting surface 110 of the waveguide is β, and the exit angle of the coupled light S15 at the center of the left edge of the display screen at the light emitting surface 110 of the waveguide is α 左 , the angle between the out-coupling beam splitter surface 201 and the waveguide light-emitting surface 110 is δ, the angle between the light S16 and the out-coupling beam splitter surface 201 is η, the incident angle of the right edge center field out-coupling light S17 of the left mirror stray light on the waveguide light-emitting surface 110 is β2, the exit angle of the right edge center field out-coupling light S17 of the left mirror stray light on the waveguide light-emitting surface 110 is α2, the refractive index of the waveguide is n, and the following relationship can be obtained: , , , , , In summary, the relationship between α2 and α can be obtained: .

[0033] When α1=α2, the horizontal field of view of the display screen is the largest, where α 左 =α 右 , the angle δ between the outcoupling beam splitter 201 and the waveguide light output surface 110 is calculated to be 36︒. When the waveguide refractive index n=2, the lateral viewing angle of the display screen is 76.3°, which is much larger than the lateral viewing angle of 52.9︒ in the prior art. When the waveguide refractive index n is 1.52, α1 and α2 are calculated to be 42.1︒. The calculation formula of the central viewing angle of the blue arc is consistent with that in the prior art, and α 蓝弧 is 51.2︒, it can be seen that α1, α2 and α 蓝弧 Both are greater than 39.5︒, that is, the left and right mirror stray light and the blue arc cannot enter the human eye. The waveguide plate structure provided by the embodiment of the present invention can prevent the left and right mirror stray light and the blue arc from entering the human eye when the refractive index of the waveguide plate n≥1.52.

[0034] Figure 8 is a light path diagram of stray light reflected from the outside in the waveguide provided by an embodiment of the present invention, Figure 8 The middle dotted line is the propagation path of the external reflected stray light. Figure 4 and Figure 8As shown, in the waveguide sheet of the prior art, the external reflected stray light only needs to be reflected once at the out-coupling beam splitter surface 201' before entering the eye, and the intensity of the external reflected stray light observed by the eye is usually 10% to 30% of the external incident light. However, in the waveguide sheet provided by the embodiment of the present invention, the external reflected stray light must undergo at least two reflections at the out-coupling beam splitter surface 201 and one total reflection at the waveguide surface before entering the human eye, and the above process includes at least one large-angle reflection. By designing the out-coupling beam splitter surface film system, the reflectivity of the large-angle reflection in the waveguide sheet can be controlled to be less than 5%. Therefore, the waveguide sheet provided by the embodiment of the present invention can attenuate the intensity of the external reflected stray light to a negligible level. Fig. 9 It is a graph showing the relationship between the reflectivity of the film system of the out-coupling splitter surface and the incident angle in the prior art. Fig.10 is a graph showing the relationship between the reflectivity of the film system and the incident angle of the outcoupling beam splitter provided by an embodiment of the present invention, combined with Fig. 9 and Fig.10 As shown, the film system needs to have a certain reflectivity within a specific small angle range to couple the incident light to form a display screen. In addition, the reflectivity needs to be lowered within a large angle range to reduce the problem of mirror stray light. In the prior art, since the angle between the outcoupling splitter surface and the waveguide surface is usually around 25°, the small angle working angle range of the film system in the prior art is usually between 15° and 37°, and the large angle working angle range is usually between 66° and 88°. Due to the inherent characteristics of the film system, the reflectivity of the film system will increase sharply when the incident angle is greater than 83°, which brings great difficulty to the coating design. In the waveguide provided in the embodiment of the present invention, the angle between the out-coupling beam splitter surface 201 and the light-emitting surface 110 of the waveguide is greater than or equal to 34° and less than or equal to 38°, which makes the small-angle working angle range of the film system in the embodiment of the present invention generally between 25︒ and 47︒, and the large-angle working angle range is generally between 66︒ and 83︒, which alleviates the problem of increased design difficulty caused by the sharp increase in the large-angle incident reflectivity of the film system. The S light reflectivity of the out-coupling beam splitter film system in the embodiment of the present invention shows an increasing trend in the small angle range of 25° to 47°, and the P light reflectivity shows a decreasing trend in the small angle range of 25° to 47°. The reflectivity of the S light and the P light is minimized in the large angle range of 61° to 83°, so that the intensity of the external reflected stray light entering the eye can be reduced to less than 1% of the external incident light.

[0035] The optical waveguide device provided by the embodiment of the present invention changes the propagation path of the light in the waveguide plate by adjusting the structures of the coupling-in region and the coupling-out region, thereby increasing the exit angle of the central field coupling-out light of the left and right mirror stray light and the blue arc on the light-emitting surface of the waveguide plate, avoiding the left and right mirror stray light and the blue arc from entering the human eye, and improving the display effect of the display picture output by the optical waveguide device; at the same time, the refractive index of the waveguide plate is greater than or equal to 1.52, which can eliminate the left and right mirror stray light and the blue arc, and the conventional glass with a refractive index of 1.52 is relatively low in cost, thereby reducing the manufacturing cost of the optical waveguide device; in addition, the optical waveguide device optimizes the working angle range of the coupling-out beam splitter surface, reduces the design difficulty of the film system of the coupling-out beam splitter surface, weakens the intensity of the external reflected stray light entering the eye, and improves the display effect of the display picture output by the optical waveguide device.

[0036] Fig.11 is a light path diagram of incident light propagating in a waveguide provided by an embodiment of the present invention, combined with Figure 5 and Fig.11 As shown, the incident light is incident from the coupling-in surface 101 into the waveguide plate, and after total reflection transmission in the waveguide plate, it is coupled out to the human eye from multiple coupling-out light splitting surfaces 201. The coupling-out light splitting surfaces 201 can reflect part of the incident light and allow the rest of the incident light to pass through. The multiple coupling-out light splitting surfaces 201 can realize pupil expansion of the incident light in the first direction X.

[0037] Fig.12 is a light path diagram of incident light of different fields of view coupled into the waveguide provided by an embodiment of the present invention, wherein the dotted line represents the incident light, and the reference Fig.12 When incident light rays of different fields of view are incident from the coupling-in surface 101 to the waveguide and are transmitted through total reflection in the waveguide, the light rays are connected end to end. Fig.13 This is the optical path diagram of incident light at different angles propagating in a waveguide without a protruding structure. Fig.12 and Fig.13 As shown in FIG. 1 , since the total reflection step length of the incident light in the waveguide is large, if the coupling structure of the waveguide does not include a protruding structure, the light will be discontinuous, such as Fig.13 The light shown will produce discontinuous dark bands in the outcoupling area, affecting the brightness uniformity of the displayed image. However, the convex structure in the waveguide provided by the embodiment of the present invention allows the incident light to be connected end to end in the waveguide, thereby improving the uniformity of the displayed image.

[0038] Optionally, the optical waveguide device further comprises a dielectric layer disposed on both surfaces of the waveguide sheet, wherein the refractive index of the dielectric layer is less than the refractive index of the waveguide sheet. The dielectric layer is coated on both surfaces of the waveguide sheet by a coating or bonding process, and the thickness of the dielectric layer is greater than 1 μm. Exemplarily, the material of the dielectric layer comprises glue, resin, silicone or dielectric material.

[0039] Based on the same inventive concept, an embodiment of the present invention provides an optical waveguide device, Fig.14 is a schematic diagram of the structure of another optical waveguide device provided by an embodiment of the present invention, referring to Fig.14 The optical waveguide device includes a waveguide plate, the waveguide plate includes a coupling-in region 300 and a coupling-out region 400, the thickness of the coupling-in region 300 is greater than the thickness of the coupling-out region 400, the coupling-in region 300 and the coupling-out region 400 are flush on one side of the light-emitting surface 310 of the waveguide plate, and the coupling-in region 300 is convex to the side away from the light-emitting surface 310 of the waveguide plate; the coupling-in region 300 includes a coupling-in reflection surface 301 located on the side wall of the waveguide plate or in the waveguide plate, and the coupling-out region 400 includes a plurality of flat The out-coupling splitter surface 401 is arranged in a row, the angle between the coupling-in reflecting surface 301 and the first direction X is greater than or equal to 34° and less than or equal to 38°, the angle between the out-coupling splitter surface 401 and the second direction Y is greater than or equal to 34° and less than or equal to 38°, the first direction X and the second direction Y are both parallel to the light emitting surface of the waveguide plate, the first direction X is directed from the coupling-in region 300 to the side of the out-coupling region 400, and the second direction Y is directed from the out-coupling region 400 to the side of the coupling-in region 300.

[0040] Combination Figure 5 and Fig.14 As shown, Fig.14 The thickness of the raised structure of the optical waveguide device is smaller, and at the same time, it can also prevent left-mirror stray light, right-mirror stray light, blue arc and external reflected stray light from entering the human eye.

[0041] Fig.15 is a light path diagram of an incident light beam propagating in another waveguide provided by an embodiment of the present invention, with reference to Fig.15 The incident light enters from the light-emitting surface 310 of the waveguide, is reflected by the coupling-in reflection surface 301, is transmitted by total reflection in the waveguide, and is coupled out to the human eye from the multiple coupling-out splitting surfaces 401.

[0042] Fig.16 FIG. 1 is a light path diagram of incident light of different viewing fields propagating in another waveguide sheet provided by an embodiment of the present invention, wherein the dotted line represents the incident light, and the reference Fig.16 , the incident light of different fields of view is incident from the light emitting surface 310 of the waveguide, and after being reflected by the coupling reflection surface 301 and transmitted by total reflection in the waveguide, the light is connected end to end.

[0043] Optionally, the optical waveguide device further comprises a dielectric layer disposed on both surfaces of the waveguide sheet, wherein the refractive index of the dielectric layer is less than the refractive index of the waveguide sheet. The dielectric layer is coated on both surfaces of the waveguide sheet by a coating or bonding process, and the thickness of the dielectric layer is greater than 1 μm. Exemplarily, the material of the dielectric layer comprises glue, resin, silicone or dielectric material.

[0044] Based on the same inventive concept, an embodiment of the present invention provides an optical waveguide device, Fig.17 is a schematic diagram of the structure of another optical waveguide device provided by an embodiment of the present invention, referring to Fig.17 The optical waveguide device includes a waveguide plate, the waveguide plate includes a first surface 510 and a second surface 520 arranged in parallel; the waveguide plate includes a coupling-in region 500 and a coupling-out region 600, the coupling-in region 500 includes a plurality of coupling-in splitting surfaces 501 arranged in parallel, the coupling-out region 600 includes a plurality of coupling-out splitting surfaces 601 arranged in parallel, the angle between the coupling-in splitting surfaces 501 and the first direction X is greater than or equal to 34° and less than or equal to 38°, the angle between the coupling-out splitting surfaces 601 and the second direction Y is greater than or equal to 34° and less than or equal to 38°, the first direction X and the second direction Y are both parallel to the second surface 520, the first direction X points from the coupling-in region 500 to one side of the coupling-out region 600, and the second direction Y points from the coupling-out region 600 to one side of the coupling-in region 500.

[0045] Fig.18 is a light path diagram of incident light propagating in another waveguide provided by an embodiment of the present invention, combined with Fig.12 , Fig.13 and Fig.18 As shown, the incident light is incident from the second surface 520, reflected by the multiple coupling-in splitting surfaces 501, and after total reflection transmission in the waveguide plate, coupled out from the multiple coupling-out splitting surfaces 601 to the human eye. Fig.13 When the light is incident on a waveguide without a protruding structure, a discontinuous dark band will be generated in the outcoupling area. However, the waveguide provided in the embodiment of the present invention includes multiple coupling-in splitting surfaces 501, and the incident light coupled from the multiple coupling-in splitting surfaces 501 can complement each other, thereby eliminating the problem of uneven distribution of the incident light in space.

[0046] Optionally, the optical waveguide device further includes a dielectric layer ( Fig.17 The dielectric layer is coated on the first surface 510 and the second surface 520 by a coating or bonding process, and the thickness of the dielectric layer is greater than 1 μm. Exemplarily, the material of the dielectric layer includes glue, resin, silicone or dielectric material.

[0047] Fig.19 is a schematic diagram of a two-dimensional array waveguide structure provided by an embodiment of the present invention, combined with Figure 5 , Fig.14 , Fig.17 and Fig.19 As shown, the coupling-in structure and coupling-out structure of the two-dimensional array waveguide are similar to Figure 5 , Fig.14 or Fig.17 Similar to the optical waveguide device in.

[0048] Based on the same inventive concept, an embodiment of the present invention provides a near-eye display device, which includes an optical machine and an optical waveguide device provided by any embodiment of the present invention.

[0049] Since the near-eye display device includes the optical waveguide device provided by any embodiment of the present invention, the near-eye display device has the same or corresponding technical effects as the optical waveguide device.

[0050] The above specific implementations do not constitute a limitation on the scope of protection of this invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. An optical waveguide device, characterized in that: A waveguide plate is included, wherein the waveguide plate includes an incoupling region and an outcoupling region, and the thickness of the incoupling region is greater than the thickness of the outcoupling region; The light-emitting surface of the waveguide plate is a first plane, and the waveguide plate further comprises a second plane opposite to the first plane, the coupling-in region and the coupling-out region are flush on one side of the second plane, and the coupling-in region bulges toward a side away from the second plane; The coupling-in region includes a coupling-in surface located on the side wall of the waveguide plate, and the out-coupling region includes a plurality of out-coupling splitting surfaces arranged in parallel, the angle between the coupling-in surface and the first direction is greater than or equal to 68° and less than or equal to 76°, the angle between the out-coupling splitting surface and the first direction is greater than or equal to 34° and less than or equal to 38°, and the first direction is parallel to the light-emitting surface of the waveguide plate and points from the coupling-in region to one side of the out-coupling region.

2. The optical waveguide device according to claim 1, characterized in that The incident light enters the waveguide plate from the coupling-in surface, and after being totally reflected and transmitted in the waveguide plate, is coupled out from the plurality of coupling-out light-splitting surfaces to the human eye.

3. The optical waveguide device according to claim 2, characterized in that: When incident light rays of different viewing fields are incident from the coupling-in surface into the waveguide plate and are transmitted through total reflection in the waveguide plate, the light rays are connected end to end.

4. The optical waveguide device according to claim 1, characterized in that It also includes a dielectric layer arranged on two surfaces of the waveguide plate, and the refractive index of the dielectric layer is smaller than the refractive index of the waveguide plate.

5. An optical waveguide device, characterized in that: A waveguide plate is included, wherein the waveguide plate includes an incoupling region and an outcoupling region, the thickness of the incoupling region is greater than the thickness of the outcoupling region, the incoupling region and the outcoupling region are flush on one side of a light-emitting surface of the waveguide plate, and the incoupling region is convex toward a side away from the light-emitting surface of the waveguide plate; The coupling-in region includes a coupling-in reflection surface located on the side wall of the waveguide plate or inside the waveguide plate, and the coupling-out region includes a plurality of parallel coupling-out splitting surfaces, the angle between the coupling-in reflection surface and the first direction is greater than or equal to 34° and less than or equal to 38°, the angle between the coupling-out splitting surface and the second direction is greater than or equal to 34° and less than or equal to 38°, the first direction and the second direction are both parallel to the light-emitting surface of the waveguide plate, the first direction points from the coupling-in region to one side of the splitting surface, and the second direction points from the splitting surface to one side of the coupling-in region.

6. The optical waveguide device according to claim 5, characterized in that The incident light is incident from the light-emitting surface of the waveguide plate, is reflected by the coupling-in reflection surface, is transmitted by total reflection in the waveguide plate, and is coupled out to the human eye from the multiple coupling-out splitting surfaces.

7. The optical waveguide device according to claim 6, characterized in that: The incident light of different viewing fields is incident from one side of the light emitting surface of the waveguide plate, and after being reflected by the coupling reflection surface, the light is transmitted through total reflection in the waveguide plate, and the light is connected end to end.

8. The optical waveguide device according to claim 6, characterized in that It also includes a dielectric layer arranged on two surfaces of the waveguide plate, and the refractive index of the dielectric layer is smaller than the refractive index of the waveguide plate.

9. An optical waveguide device, characterized in that: A waveguide sheet is provided, wherein the waveguide sheet comprises a first surface and a second surface arranged in parallel; The waveguide plate includes a coupling-in region and a coupling-out region, the coupling-in region includes a plurality of coupling-in splitting surfaces arranged in parallel, the coupling-out region includes a plurality of coupling-out splitting surfaces arranged in parallel, the angle between the coupling-in splitting surface and the first direction is greater than or equal to 34° and less than or equal to 38°, the angle between the coupling-out splitting surface and the second direction is greater than or equal to 34° and less than or equal to 38°, the first direction and the second direction are both parallel to the second surface, the first direction is directed from the coupling-in region to one side of the coupling-out region, and the second direction is directed from the out coupling region to one side of the coupling-in region.

10. The optical waveguide device according to claim 9, characterized in that The incident light is incident from the second surface, reflected by the multiple coupling-in splitting surfaces, and after being totally reflected and transmitted in the waveguide plate, is coupled out from the multiple coupling-out splitting surfaces to the human eye.

11. The optical waveguide device according to claim 9, characterized in that The invention also includes a dielectric layer disposed on the first surface and the second surface, wherein the refractive index of the dielectric layer is smaller than the refractive index of the waveguide plate.

12. A near-eye display device, characterized in that: It comprises an optical machine and the optical waveguide device as described in any one of claims 1 to 11.

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