Optical waveguide sheet, glasses frame, and smart glasses

Abstract

An optical waveguide sheet (100), a glasses frame, and smart glasses, relating to the technical field of smart glasses. The optical waveguide sheet (100) comprises a waveguide substrate (10), a coupling-in area (20), and a coupling-out area (30); and the coupling-in area (20) and the coupling-out area (30) are arranged on the waveguide substrate (10), the coupling-in area (20) is used for coupling light into the waveguide substrate (10), and the coupling-out area (30) is used for coupling light propagating in the waveguide substrate (10) out, wherein the bottom edge of the coupling-out area (30) is located on the upper side of a horizontal bisector of the optical waveguide sheet (100), or all or part of the bottom edge of the coupling-out area (30) is flush with the horizontal bisector of the optical waveguide sheet (100). The problem of a user being unable to wear smart glasses for a long time due to the occurrence of rainbow patterns on the smart glasses is solved.

Description

Optical waveguides, frames, and smart glasses Technical Field

[0001] The present application relates to the technical field of smart glasses, and in particular to an optical waveguide, a frame and smart glasses. Background Art

[0002] Smart glasses generally achieve their display functions through optical waveguide solutions. The grating area (coupling area and outcoupling area) of the optical waveguide mainly plays the role of transmitting optical light and increasing the eye box area (pupil expansion). However, it also diffracts the natural light that passes through the outcoupling area in the real environment. As a result, when users use smart glasses to view the real world, some diffraction rainbow stripes that do not exist in reality will appear, resulting in a poor user experience.

[0003] Summary of the Invention

[0004] The present application provides an optical waveguide, a frame and smart glasses, which can solve the problem that users cannot wear smart glasses for a long time due to the appearance of rainbow lines on smart glasses.

[0005] In a first aspect, the present application provides an optical waveguide sheet including a waveguide substrate, an incoupling region, and an outcoupling region, wherein the incoupling region and the outcoupling region are provided on the waveguide substrate, the incoupling region being used to couple light into the waveguide substrate, and the outcoupling region being used to couple light propagating in the waveguide substrate out;

[0006] The bottom edge of the outcoupling region is located above the horizontal bisector of the optical waveguide plate, or all or part of the bottom edge of the outcoupling region is flush with the horizontal bisector of the optical waveguide plate.

[0007] In a second aspect, the present application also provides a frame comprising a light-emitting component, a frame and the optical waveguide as described above, wherein the light-emitting component is used to emit display light; and the optical waveguide is fixedly installed in the frame.

[0008] In a third aspect, the present application also provides a pair of smart glasses comprising the optical waveguide sheet as described above.

[0009] The present application provides an optical waveguide sheet, a frame, and smart glasses. The optical waveguide sheet includes a waveguide substrate, an incoupling region, and an outcoupling region. The incoupling region and the outcoupling region are disposed on the waveguide substrate, the incoupling region being used to couple light into the waveguide substrate, and the outcoupling region being used to couple light propagating within the waveguide substrate out. The bottom edge of the outcoupling region is located above the horizontal bisector of the optical waveguide sheet, or the bottom edge of the outcoupling region is flush with the horizontal bisector of the optical waveguide sheet. Thus, by changing the position of the outcoupling region on the optical waveguide sheet, the outcoupling region can be moved out of the center of the main field of view of the smart glasses, effectively avoiding diffraction rainbow fringes in the wearer's main field of view, while also ensuring that the AR imaging function is implemented within the effective area. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0011] FIG1 is a schematic diagram showing the implementation principle of an optical waveguide sheet of related art provided in an embodiment of the present application;

[0012] FIG2( a ) is a schematic structural diagram of an optical waveguide sheet of related art provided in an embodiment of the present application;

[0013] FIG2( b ) is a schematic structural diagram of another optical waveguide sheet of related technology provided in an embodiment of the present application;

[0014] FIG3( a ) is a schematic structural diagram of an optical waveguide provided in an embodiment of the present application;

[0015] FIG3( b ) is a schematic structural diagram of another optical waveguide provided in an embodiment of the present application;

[0016] FIG4 is a schematic diagram of an application scenario of an optical waveguide provided in an embodiment of the present application;

[0017] FIG5( a ) is a schematic structural diagram of an outcoupling region provided in an embodiment of the present application;

[0018] FIG5( b ) is a schematic structural diagram of another outcoupling region provided in an embodiment of the present application;

[0019] FIG6 is a schematic diagram of an application scenario of another optical waveguide provided in an embodiment of the present application;

[0020] FIG7 is a schematic diagram showing the relationship between a preset angle θ and visual fatigue provided in an embodiment of the present application;

[0021] FIG8 is a schematic diagram of the cross-sectional structure of an optical waveguide provided in an embodiment of the present application;

[0022] FIG9 is a schematic cross-sectional view of another optical waveguide provided in an embodiment of the present application;

[0023] FIG10 is a schematic diagram of the cross-sectional structure of another optical waveguide provided in an embodiment of the present application;

[0024] FIG11 is a schematic cross-sectional view of another optical waveguide provided in an embodiment of the present application;

[0025] FIG12 is a schematic diagram of the cross-sectional structure of another optical waveguide provided in an embodiment of the present application;

[0026] FIG13 is a schematic cross-sectional view of another optical waveguide provided in an embodiment of the present application;

[0027] FIG14 is a schematic structural diagram of another optical waveguide provided in an embodiment of the present application;

[0028] FIG15( a ) is a schematic structural diagram of an optical waveguide plate according to an embodiment of the present application;

[0029] FIG15( b ) is a schematic structural diagram of another optical waveguide plate shape provided in an embodiment of the present application;

[0030] FIG15( c ) is a schematic structural diagram of another optical waveguide plate shape provided in an embodiment of the present application;

[0031] FIG16 is a schematic structural diagram of a frame provided by an embodiment of the present application;

[0032] FIG17 is a schematic diagram of the structure of a pair of smart glasses provided in an embodiment of the present application. DETAILED DESCRIPTION

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

[0034] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, combined, or partially merged, so the actual execution order may vary depending on the actual situation.

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

[0036] It will also be understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0037] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0038] Smart glasses typically achieve their display functionality through an optical waveguide solution (i.e., an optical waveguide sheet). As shown in Figure 1, the optical waveguide sheet is one of the primary optical components in the smart glasses' display system. Light emitted by the optical engine of the smart glasses enters the waveguide sheet's incoupling region, undergoes diffraction there, and then undergoes total internal reflection within the sheet's functional layer. This light is then transmitted to the outcoupling region, where it undergoes further diffraction before entering the human eye to form an image.

[0039] For AR glasses, the optical waveguide used for imaging must not only display virtual projection information but also, like ordinary eyeglass lenses, transmit real-world light, enabling the superposition of real-world and virtual images. However, the grating regions (incoupling and outcoupling regions) of the optical waveguide diffract natural light that passes through the outcoupling regions. This can cause the user to see rainbow fringes when viewing the real world through smart glasses, which do not exist in reality.

[0040] As shown in Figures 2(a) and 2(b), the outcoupling area of ​​existing smart glasses is essentially located in the center of the main field of view (FOV). To achieve the ultimate in AR imaging quality and an immersive viewing experience, existing smart glasses increase the field of view (FOV). As a result, the outcoupling area occupies more of the center of the lens' FOV. Within this large outcoupling area, the appearance of diffraction rainbow fringes is further amplified, making it difficult for the wearer to wear and use the glasses for daily use when not using AR.

[0041] To address the shortcomings of the above-mentioned prior art, the present application proposes an optical waveguide sheet, a frame, and smart glasses. The optical waveguide sheet can be used in smart glasses. By changing the position of the outcoupling region within the optical waveguide sheet, the outcoupling region can be moved out of the center of the main field of view of the smart glasses, effectively avoiding diffraction rainbow fringes in the wearer's main field of view while ensuring that AR imaging functions can be achieved within the effective area.

[0042] Exemplarily, the smart glasses may be AR (Augmented Reality) glasses, VR (Virtual Reality) glasses, or any other electronic device that can be used for AR imaging, such as smart wearable devices such as smart helmets, without specific limitation herein.

[0043] Please refer to FIG3( a ), which is a schematic structural diagram of an optical waveguide provided in an embodiment of the present application.

[0044] As shown in FIG3(a), the optical waveguide sheet 100 includes a waveguide substrate 10, an incoupling region 20, and an outcoupling region 30. Both the incoupling region 20 and the outcoupling region 30 are provided on the waveguide substrate 10. The incoupling region 20 and the outcoupling region 30 can be provided at different locations on the first surface of the waveguide substrate 10. The incoupling region 20 is used to couple light into the waveguide substrate 10, and the outcoupling region 30 is used to couple light propagating within the waveguide substrate 10 out.

[0045] The light diffracted by the coupling-in region 20 can be totally reflected in the waveguide substrate 10 , thereby achieving lateral transmission of the light until it is diffracted again by the coupling-out region 30 and reaches the human eye to form an image.

[0046] For example, the incoupling region 20 and the outcoupling region 30 may be disposed on different surfaces of the waveguide substrate 10, for example, the incoupling region 20 may be disposed on the first surface of the waveguide substrate 10, and the outcoupling region 30 may be disposed on the second surface of the waveguide substrate 10, or the outcoupling region 30 may be disposed on the first surface of the waveguide substrate 10, and the incoupling region 20 may be disposed on the second surface of the waveguide substrate 10. As long as the incoupling region 20 can be used to couple light into the waveguide substrate 10 and the outcoupling region 30 can be used to couple out light propagating within the waveguide substrate 10, it is sufficient.

[0047] For example, the position of the coupling-in region 20 on the waveguide substrate 10 can be set according to the position of the light-emitting component 200 , as long as the coupling-in region 20 can receive the light emitted by the light-emitting component 200 .

[0048] Specifically, the center position of the outcoupling region 30 is located above the projection position of the wearer's eye pupil center on the optical waveguide sheet.

[0049] As shown in Figure 4 , under normal circumstances, the intersection of the line of sight and the light guide sheet 100 when the human eye is looking straight ahead is not at the center of the light guide sheet. Instead, the intersection can be located at the 0.618 golden section point of the light guide sheet 100. In other words, the projection position of the center of the human pupil on the light guide sheet 100 is different from the center of the light guide sheet 100. The projection position of the center of the human pupil on the light guide sheet 100 can be located above the center of the light guide sheet 100. Therefore, the main field of view of the smart glasses is the field of view centered on the projection position of the center of the human pupil on the light guide sheet 100.

[0050] The outcoupling region 30 may or may not overlap with the primary field of view of the smart glasses, without any specific limitation herein. It is understood that as long as the center of the outcoupling region 30 is located above the projection position of the wearer's pupil center onto the optical waveguide sheet 100, diffraction rainbow fringes appearing in the wearer's primary field of view can be effectively reduced.

[0051] It should be noted that the center position of the outcoupling region 30 can be the center point or the center region of the outcoupling region 30; this is not specifically limited herein. The center position of the outcoupling region 30 being located above the projection position of the wearer's eye pupil center onto the optical waveguide sheet 100 can be expressed as the center position of the outcoupling region 30 being located above the projection position of the wearer's eye pupil center onto the optical waveguide sheet 100 in the y-axis direction.

[0052] For example, the center position of the outcoupling area 30 can be located on the upper left side of the projection position of the wearer's human eye pupil center on the optical waveguide plate 100, or it can be located directly above the projection position of the wearer's human eye pupil center on the optical waveguide plate 100, or it can be located on the upper right side of the projection position of the wearer's human eye pupil center on the optical waveguide plate 100, and no specific limitation is made here.

[0053] Meanwhile, the projection position of the wearer's eye pupil center on the optical waveguide sheet 100 can be on the left side, the middle, or the right side of the optical waveguide sheet 100. It is sufficient as long as the center of the outcoupling region 30 is set above the projection position of the wearer's eye pupil center on the optical waveguide sheet 100.

[0054] Among them, the x-axis direction can be the horizontal direction of the outcoupling area 30 in the plane where the wearer's line of sight is directly located, that is, the length direction of the outcoupling area 30; the y-axis direction can be the vertical direction of the outcoupling area 30 in the plane where the wearer's line of sight is directly located, that is, the width direction of the outcoupling area 30; the z-axis direction can be the direction of the wearer's line of sight, and is a direction perpendicular to the x-axis direction and the y-axis direction, that is, the thickness direction of the outcoupling area 30.

[0055] An embodiment of the present application provides an optical waveguide sheet 100, comprising a waveguide substrate 10, an incoupling region 20, and an outcoupling region 30. The incoupling region 20 and the outcoupling region 30 are disposed on the waveguide substrate 10. The incoupling region 20 is used to couple light into the waveguide substrate 10, and the outcoupling region 30 is used to couple light propagating within the waveguide substrate 10 outward. The center of the outcoupling region 30 is located above the projection of the wearer's eye pupil center onto the optical waveguide sheet 100. By changing the position of the outcoupling region 30 on the optical waveguide sheet 100, the outcoupling region 30 can be moved out of the center of the main field of view of the smart glasses, effectively avoiding diffraction rainbow fringes in the wearer's main field of view. This also ensures that AR imaging is implemented within the effective area, allowing the wearer to clearly and accurately see the information displayed in the outcoupling region 30 even with a slight eye lift.

[0056] As shown in FIG3(b), in some embodiments, the optical waveguide sheet 100 includes a waveguide substrate 10, an incoupling region 20, and an outcoupling region 30. Both the incoupling region 20 and the outcoupling region 30 are disposed on the waveguide substrate 10. The incoupling region 20 and the outcoupling region 30 can be disposed at different locations on the first surface of the waveguide substrate 10. The incoupling region 20 is used to couple light into the waveguide substrate 10, and the outcoupling region 30 is used to couple light propagating within the waveguide substrate 10.

[0057] The light diffracted by the coupling-in region 20 can be totally reflected in the waveguide substrate 10 , thereby achieving lateral transmission of the light until it is diffracted again by the coupling-out region 30 and reaches the human eye to form an image.

[0058] For example, the incoupling region 20 and the outcoupling region 30 may be disposed on different surfaces of the waveguide substrate 10, for example, the incoupling region 20 may be disposed on the first surface of the waveguide substrate 10, and the outcoupling region 30 may be disposed on the second surface of the waveguide substrate 10, or the outcoupling region 30 may be disposed on the first surface of the waveguide substrate 10, and the incoupling region 20 may be disposed on the second surface of the waveguide substrate 10. As long as the incoupling region 20 can be used to couple light into the waveguide substrate 10 and the outcoupling region 30 can be used to couple out light propagating within the waveguide substrate 10, it is sufficient.

[0059] For example, the position of the coupling-in region 20 on the waveguide substrate 10 can be set according to the position of the light-emitting component 200 , as long as the coupling-in region 20 can receive the light emitted by the light-emitting component 200 .

[0060] Specifically, the bottom side of the outcoupling region 30 is located above the horizontal bisector of the optical waveguide plate 100 , or all or part of the bottom side of the outcoupling region 30 is flush with the horizontal bisector of the optical waveguide plate 100 .

[0061] The bottom side of the outcoupling region 30 may be a parallel line where the lowest endpoint of the outcoupling region 30 in the vertical direction (ie, the y-axis direction) is located.

[0062] For example, if the lower edge of the outcoupling area 30 is a parallel line, for example, the outcoupling area 30 is a rectangle, the lower edge of the outcoupling area 30 may be the lower base of the rectangle; if the lower edge of the outcoupling area 30 is an arc, the lower edge of the outcoupling area 30 may be a parallel line where the top of the arc is located. The bottom edge of the outcoupling area 30 may also be set according to different situations, and is not specifically limited here.

[0063] As shown in Figure 2(b), under normal circumstances, the outcoupling region 30 is generally located in the middle of the optical waveguide sheet 100, that is, the bottom edge of the outcoupling region 30 is located below the horizontal bisector of the optical waveguide sheet 100. Therefore, the outcoupling region 30 and the main field of view of the smart glasses will have a large overlap area, resulting in a large number of diffraction rainbow fringes in the wearer's main field of view.

[0064] As shown in FIG3(b), by setting the bottom edge of the out-coupling region 30 to be located above the horizontal bisector of the optical waveguide plate 100, or by setting all or part of the bottom edge of the out-coupling region 30 to be flush with the horizontal bisector of the optical waveguide plate 100, since the appearance of rainbow stripes is caused by the grating at the bottom edge of the optical waveguide plate 100, the diffraction rainbow stripes appearing in the wearer's main field of view can be reduced by moving the out-coupling region 30 upward. Experiments have shown that by setting the bottom edge of the out-coupling region 30 to be at least flush with or above the horizontal bisector of the optical waveguide plate 100, the diffraction rainbow stripes appearing in the wearer's main field of view can be effectively reduced, and the influence of the rainbow stripes on the wearer can be basically eliminated.

[0065] For example, the bottom edge of the outcoupling region 30 may be located to the upper left of the horizontal bisector of the optical waveguide sheet 100, directly above the horizontal bisector of the optical waveguide sheet 100, or to the upper right of the horizontal bisector of the optical waveguide sheet 100, without specific limitation herein. It is sufficient as long as the bottom edge of the outcoupling region 30 is located above the horizontal bisector of the optical waveguide sheet 100 or flush with the horizontal bisector of the optical waveguide sheet 100.

[0066] An embodiment of the present application provides an optical waveguide sheet 100, which includes a waveguide substrate 10, an incoupling region 20, and an outcoupling region 30. The incoupling region 20 and the outcoupling region 30 are provided on the waveguide substrate 10. The incoupling region 20 is used to couple light into the waveguide substrate 10, and the outcoupling region 30 is used to couple light propagating within the waveguide substrate 10 out. The bottom edge of the outcoupling region 30 is located above a horizontal bisector of the optical waveguide sheet 100, or all or part of the bottom edge of the outcoupling region 30 is flush with the horizontal bisector of the optical waveguide sheet 100. Since people spend most of their time looking forward and downward in their daily lives, the wearer's main field of view is located in the lower middle of the optical waveguide sheet 100. The present application can change the position of the outcoupling area 30 on the optical waveguide sheet 100, thereby moving the outcoupling area 30 out of the center area of ​​the main field of view of the smart glasses, effectively avoiding the diffraction rainbow stripes that appear in the wearer's main field of view. At the same time, it can also ensure that the AR imaging function is realized in the effective area, so that the wearer can clearly and accurately see the display information of the outcoupling area 30 even if the wearer slightly raises his eyes.

[0067] In some embodiments, the center position of the outcoupling region 30 includes one of a center point of the outcoupling region 30 and a bisector in the horizontal direction. Thus, even when the outcoupling region 30 is irregular in shape, the center position of the outcoupling region 30 can be accurately determined.

[0068] The center point of the outcoupling region 30 may be the center point of the shape corresponding to the outcoupling region 30 ; and the horizontal bisector of the outcoupling region 30 is equidistant from the upper and lower edges of the outcoupling region 30 .

[0069] Specifically, if the center point of the outcoupling region 30 is relatively easy to determine, for example, if the shape of the outcoupling region 30 is regular, the center point of the outcoupling region 30 can be quickly determined by simple calculation; for example, if the shape of the outcoupling region 30 is irregular, the center point can be determined by finding the center point of the circumscribed circle of the outcoupling region 30.

[0070] Specifically, if it is difficult to determine the center point of the outcoupling region 30, for example, the shape of the outcoupling region 30 is irregular, the horizontal bisector of the outcoupling region 30 can be found by determining a horizontal line with equal distances between the upper and lower edges of the outcoupling region 30.

[0071] For example, if the upper side line or the lower side line is an irregular line, such as an arc line, the midpoint of the upper side line and the lower side line can be determined, and then a horizontal line with an equal distance from the midpoint of the upper side line and the midpoint of the lower side line can be found to find the horizontal bisector of the coupling-out region 30.

[0072] The horizontal direction may be the x-axis direction, i.e., the length direction of the outcoupling region 30. Generally, the outcoupling region 30 is a regular shape such as a rectangle or a rounded rectangle, so the center position of the outcoupling region 30 can be determined by finding the center point of the outcoupling region 30.

[0073] As shown in FIG. 5( a ), illustratively, if the outcoupling region 30 is a rectangle, the center point of the outcoupling region 30 can be determined by the intersection of the diagonals of the rectangle, thereby accurately determining the center position of the outcoupling region 30 .

[0074] As shown in FIG. 5( b ), for example, if the outcoupling region 30 is an irregular shape, a horizontal line that determines the same distance between the upper and lower edges of the outcoupling region 30 can be found, and the midpoint of the horizontal line is used as the center position of the outcoupling region 30 .

[0075] As shown in Figure 6, the center of the outcoupling region 30 and the projection of the center of the human pupil on the optical waveguide sheet 100 form a predetermined angle θ relative to the projection of the center of the wearer's human pupil on the plane of the cross-section of the optical waveguide sheet 100. This predetermined angle θ is less than or equal to 30°. This prevents the outcoupling region 30 from being positioned too high above the AR imaging area, forcing the wearer to raise their eyes more to clearly and accurately see the information displayed on the outcoupling region 30, and causing increased visual fatigue for the wearer.

[0076] The preset angle θ is the angle between the center of the outcoupling region 30 and the projection position of the human pupil center on the optical waveguide 100 relative to the plane of the cross section of the wearer's human pupil center on the optical waveguide 100 .

[0077] It can be understood that as long as the center position of the out-coupling area 30 and the projection position of the center of the human eye pupil on the optical waveguide plate 100 form a preset angle θ relative to the projection position of the center of the wearer's human eye pupil on the plane of the cross-section of the optical waveguide plate 100, and the center position of the out-coupling area 30 is located on the upper side of the projection position of the center of the human eye pupil on the optical waveguide plate 100, the diffraction rainbow fringes appearing in the wearer's main field of view can be reduced.

[0078] Please refer to Figure 7, which is a schematic diagram of the relationship between a preset angle θ and visual fatigue provided in an embodiment of the present application. As shown in Figure 7, when the preset angle θ is greater than 30°, because the decoupling area 30 is set too high, the wearer needs to raise their eyes for a long time, and the amplitude of the eye lift is large, in order to clearly and accurately see the display information of the decoupling area 30. At this time, the visual fatigue level of the wearer after wearing the glasses for more than 30 minutes exceeds 2, which means that the user will feel very uncomfortable after wearing the glasses for more than 30 minutes. Therefore, the preset angle θ needs to be set to be less than or equal to 30°.

[0079] In some embodiments, the center of the outcoupling region 30 and the projection of the center of the human eye pupil on the optical waveguide sheet 100 form a predetermined angle θ relative to the projection of the center of the wearer's eye pupil on the plane of the cross-section of the optical waveguide sheet 100. The predetermined angle θ is greater than or equal to 10° and less than or equal to 20°. This allows the outcoupling region 30 to be positioned within an optimal range, effectively eliminating most diffraction rainbow fringes in the wearer's primary field of view while also minimizing visual fatigue for the wearer.

[0080] As shown in FIG7 , when the preset angle θ is less than 10°, the outcoupling area 30 may still overlap with the wearer's primary field of view due to the small size of the preset angle θ. Therefore, a small amount of diffraction rainbow fringes may still appear in the wearer's primary field of view, meaning that the elimination effect of diffraction rainbow fringes is not optimal. When the preset angle θ is greater than 20° and less than or equal to 30°, the increase in visual fatigue gradually increases as the preset angle θ increases. Therefore, when the preset angle θ is set to 20 degrees, diffraction rainbow fringes can be eliminated to the greatest extent possible, while also preventing the wearer from feeling fatigued from wearing the smart glasses for extended periods of time.

[0081] In some embodiments, the outcoupling region 30 is in the shape of a rectangle or a rounded rectangle, so that the length of the outcoupling region 30 can be greater than the width of the outcoupling region 30 , thereby making it difficult for the wearer's eyes to see the diffracted rainbow fringes.

[0082] Specifically, the width of the outcoupling region 30 can be made narrower so that the reflected natural light is less likely to enter the human eye after diffraction, thereby generating rainbow patterns.

[0083] In some embodiments, the length of the outcoupling region 30 is greater than or equal to twice the width of the outcoupling region 30. The length of the outcoupling region 30 is the horizontal distance of the outcoupling region 30, and the width of the outcoupling region 30 is the vertical distance of the outcoupling region 30. This can minimize the width of the outcoupling region 30, making it difficult for the wearer's eyes to see the diffracted rainbow fringes.

[0084] Among them, the length direction of the outcoupling area 30 can be the horizontal direction of the outcoupling area 30 in the plane where the wearer's line of sight is located, that is, the x-axis direction; the width direction of the outcoupling area 30 can be the vertical direction of the outcoupling area 30 in the plane where the wearer's line of sight is located, that is, the y-axis direction.

[0085] Specifically, the length of the outcoupling area 30 can be set to be greater than or equal to twice the width of the outcoupling area 30, thereby shortening the distance between the lower boundary of the outcoupling area 30 and the upper boundary of the main field of view area as much as possible, so that the wearer's eyes cannot easily see the diffracted rainbow stripes.

[0086] In some embodiments, the length of the outcoupling region 30 may be greater than or equal to three times the width of the outcoupling region 30. Thus, by narrowing the width of the outcoupling region 30 to a certain extent, the wearer's eyes may be less likely to see the diffracted rainbow fringes.

[0087] Specifically, when the length of the outcoupling area 30 is greater than or equal to three times the width of the outcoupling area 30, it means that the distance between the lower boundary of the outcoupling area 30 and the upper boundary of the main field of view area is relatively narrow, which means that the wearer's eyes can be prevented from seeing the diffracted rainbow stripes to the greatest extent.

[0088] It should be noted that the width of the outcoupling area 30 cannot be set too narrow. If the width of the outcoupling area 30 is set too narrow, the outcoupling area 30 may appear as a small horizontal bar, resulting in too few lines of text displayed in the outcoupling area 30.

[0089] 8 , in some embodiments, the waveguide substrate 10 further includes a grating layer 40, which is disposed on the waveguide substrate 10 to form the incoupling region 20 and / or the outcoupling region 30. Thus, the incoupling region 20 and / or the outcoupling region 30 can be formed on the waveguide substrate 10 through grating coupling.

[0090] The thickness of the grating layer 40 is in the range of 10 nanometers to 500 nanometers, so that the grating layer 40 can be set to be very thin, thereby increasing the light transmittance of the grating layer 40.

[0091] For example, the grating layer 40 can be disposed on the first surface of the waveguide substrate 10, on the second surface of the waveguide substrate 10, or inside the waveguide of the waveguide substrate 10, without specific limitation. The first surface of the waveguide substrate 10 can be the surface away from the wearer, while the second surface of the waveguide substrate 10 can be the surface close to the wearer.

[0092] For example, liquefied nanoimprint adhesive can be coated on the first surface of the waveguide substrate 10 and nanoimprinted using a mold to form a nanoscale diffraction grating structure on the first surface of the waveguide substrate 10. The nanoimprint adhesive is then cured with ultraviolet light to form the incoupling region 20 and the outcoupling region 30 of fixed shapes.

[0093] For example, a nanometer-scale diffraction grating can be formed on the first surface or the second surface of the waveguide substrate 10 by etching methods such as photolithography / ion beam etching, and then subsequent processing operations such as cleaning are performed to form the coupling-in region 20 and the coupling-out region 30 of specific shapes.

[0094] Exemplarily, the coupling-in and coupling-out regions can be volume holographic gratings. Specifically, an organic thin film can be coated on the waveguide substrate 10. The film is then exposed to light by two laser beams generating interference fringes. The light and dark interference fringes induce different exposure characteristics of the material, creating a periodic refractive index contrast (Δn) within the film, thus generating a diffraction grating.

[0095] In some embodiments, the optical waveguide sheet 100 further includes a first anti-reflection film 41 disposed on the surface of the grating layer 40. Thus, by disposing the anti-reflection film on the surface of the grating layer 40, the light transmittance of the grating layer 40 can be improved.

[0096] In smart glasses, the focus of related technologies is on improving the virtual reality imaging quality of optical waveguides, while neglecting the transmittance of real-world light. As a result, the real-world transmittance is generally less than 80% in the grating area (incoupling and outcoupling regions), and less than 85% in the non-grating area (non-incoupling and non-outcoupling regions). The low optical transmittance in the grating area makes the real world in the smart glasses appear dim and blurry, making it difficult for users to wear the smart glasses for extended periods of time, especially when engaging in real-world activities.

[0097] Specifically, since the optical transmittance of the grating layer 40 of the conventional optical waveguide sheet 100 is generally very low, typically less than 85%, an AR (antireflection coating) may be deposited on the surface of the grating layer 40 to form a first antireflection coating 41, thereby improving the light transmittance of the grating layer 40.

[0098] As shown in FIG9 , in some embodiments, a first antireflection film 41 is disposed around the in-coupling region 20 and the out-coupling region 30, but does not cover the in-coupling region 20 and the out-coupling region 30. Therefore, by disposing an antireflection film around the in-coupling region 20 and the out-coupling region 30 on the surface of the grating layer 40, the coating process can be simplified, coating costs can be reduced, and the diffraction effect of the grating can be avoided.

[0099] Specifically, an AR film may be deposited on the surface of the grating layer 40 around the in-coupling region 20 and the out-coupling region 30 to form a first anti-reflection film 41 , and the first anti-reflection film 41 does not cover the in-coupling region 20 and the out-coupling region 30 .

[0100] As shown in FIG10 , in some embodiments, a first antireflection film 41 is provided to cover the incoupling region 20 and the outcoupling region 30. Thus, by providing an antireflection film on the surface of the grating layer 40 covering the incoupling region 20 and the outcoupling region 30, the light transmittance of the incoupling region 20 and the outcoupling region 30 can be increased, thereby improving the visual experience.

[0101] Specifically, an AR film may be plated on the surface of the grating layer 40 to cover the coupling-in region 20 and the coupling-out region 30 to form a first antireflection film 41 , thereby increasing the light transmittance of the coupling-in region 20 and the coupling-out region 30 and improving the visual experience.

[0102] As shown in Figure 11, in some embodiments, the optical waveguide sheet 100 may further include a second anti-reflection film 11, which is disposed on the second surface of the waveguide substrate 10. Thus, by disposing the anti-reflection film on the second surface of the waveguide substrate 10, the light transmittance of the waveguide substrate 10 can be improved.

[0103] Specifically, an AR antireflection film may be plated on the second surface of the waveguide substrate 10 to form a second antireflection film 11 , thereby improving the light transmittance of the waveguide substrate 10 .

[0104] As shown in FIG12 , in some embodiments, the optical waveguide sheet 100 may further include a first protective lens 50 and a second protective lens 60. The first protective lens 50 is disposed on the side away from the wearer and is stacked with the grating layer 40. The second protective lens 60 is disposed on the side closer to the wearer and is stacked with the second surface of the waveguide substrate 10. This ensures that the total internal reflection of light within the waveguide substrate 10 of the optical waveguide sheet 100 is not interfered with by external contaminants.

[0105] The first protective lens 50 , the second protective lens 60 and the waveguide substrate 10 are generally made of resin or glass flat sheets, which can ensure that the total reflection of light in the waveguide substrate 10 of the optical waveguide sheet 100 is not interfered with by external pollutants such as grease and water.

[0106] Specifically, light from the real world is incident from the far eye side, passes through the first protective lens 50, the grating layer 40, the waveguide substrate 10 and the second protective lens 60 in sequence, and finally exits from the near eye side and enters the human eye.

[0107] Exemplarily, the first protective lens 50 is arranged on the side away from the wearer, and the first protective lens 50 is stacked with the grating layer 40, thereby ensuring that external contaminants such as grease and water cannot enter the waveguide substrate 10 on the far eye side; the second protective lens 60 is arranged on the side close to the wearer, and the second protective lens 60 is stacked with the second surface of the waveguide substrate 10, thereby ensuring that external contaminants such as grease and water cannot enter the waveguide substrate 10 on the near eye side, thereby ensuring that the total reflection of light in the waveguide substrate 10 is not disturbed.

[0108] As shown in FIG13 , in some embodiments, the optical waveguide sheet 100 may further include one or more of a third anti-reflection film 51, a fourth anti-reflection film 52, a fifth anti-reflection film 61, and a sixth anti-reflection film 62. The third anti-reflection film 51 is disposed on the first surface of the first protective lens 50; and / or the fourth anti-reflection film 52 is disposed on the second surface of the first protective lens 50; and / or the fifth anti-reflection film 61 is disposed on the first surface of the second protective lens 60; and / or the sixth anti-reflection film 62 is disposed on the second surface of the second protective lens 60. Thus, by disposing the anti-reflection films on the surfaces of the first protective lens 50 and / or the second protective lens 60, the light transmittance of the first protective lens 50 and / or the second protective lens 60 can be improved.

[0109] For example, an AR antireflection film may be deposited on the first surface of the first protective lens 50 to form the third antireflection film 51 , thereby increasing the transmittance of light entering the first protective lens 50 .

[0110] For example, an AR anti-reflection film may be deposited on the second surface of the first protective lens 50 to form a fourth anti-reflection film 52 , thereby increasing the transmittance of light exiting the first protective lens 50 .

[0111] For example, an AR antireflection film may be deposited on the first surface of the second protective lens 60 to form a fifth antireflection film 61 , thereby increasing the transmittance of light entering the second protective lens 60 .

[0112] For example, an AR antireflection film may be deposited on the second surface of the second protective lens 60 to form a sixth antireflection film 62 , thereby increasing the transmittance of light exiting the second protective lens 60 .

[0113] It should be noted that the optical waveguide sheet 100 may be provided with the third anti-reflection film 51, the fourth anti-reflection film 52, the fifth anti-reflection film 61, and the sixth anti-reflection film 62 simultaneously, or may be provided with one or more of the third anti-reflection film 51, the fourth anti-reflection film 52, the fifth anti-reflection film 61, and the sixth anti-reflection film 62, without specific limitation herein. Generally, when the optical waveguide sheet 100 is provided with the third anti-reflection film 51, the fourth anti-reflection film 52, the fifth anti-reflection film 61, and the sixth anti-reflection film 62 simultaneously, the optical waveguide sheet 100 has the highest light transmittance, thereby achieving a light transmittance greater than 90% in the outcoupling region 30 and a light transmittance greater than 95% in the non-outcoupling region 30, and no rainbow fringes within the field of view.

[0114] In some embodiments, the refractive index of the material of the waveguide substrate 10, the grating layer 40, the first protective lens 50, and the second protective lens 60 is less than or equal to 2. Therefore, by using low-refractive-index materials to form the waveguide substrate 10, the grating layer 40, the first protective lens 50, and the second protective lens 60, the light transmittance of the optical waveguide sheet 100 can be improved.

[0115] The refractive index of the materials of the waveguide substrate 10 , the grating layer 40 , the first protective lens 50 and the second protective lens 60 are all lower than or equal to 2, for example, 1.8, etc., which is not specifically limited here.

[0116] For example, a material with a refractive index of 1.8 may be selected to form the waveguide substrate 10 , the grating layer 40 , the first protective lens 50 , and the second protective lens 60 .

[0117] As shown in FIG14 , in some embodiments, the distance between the bottom edge of the outcoupling region 30 and the horizontal bisector of the optical waveguide sheet 100 is greater than or equal to 2 mm. This allows the outcoupling region 30 to be positioned within an optimal range, minimizing diffraction rainbow fringes in the wearer's primary field of view.

[0118] Specifically, the distance a between the bottom edge of the outcoupling region 30 and the horizontal bisector of the optical waveguide sheet 100 can be determined based on parameters such as the period of the outcoupling region 30. Generally, when the distance a between the bottom edge of the outcoupling region 30 and the horizontal bisector of the optical waveguide sheet 100 is greater than or equal to 2 mm, the outcoupling region 30 can be set within an optimal range, thereby minimizing diffraction rainbow fringes in the wearer's main field of view.

[0119] As shown in FIG. 14 , for example, if the outcoupling region 30 is rectangular, the distance a between the bottom side of the rectangle and the horizontal bisector of the optical waveguide plate 100 may be set to be greater than or equal to 2 mm.

[0120] For example, if the outcoupling region 30 is an irregular shape, the distance a between a parallel line at the bottommost side of the bottom edge of the irregular shape and a horizontal bisector of the optical waveguide plate 100 may be set to be greater than or equal to 2 mm.

[0121] As shown in FIG. 15( a ), FIG. 15 ( b ), and FIG. 15 ( c ), in some embodiments, the shape of the optical waveguide sheet 100 includes a circle, an ellipse, a rounded rectangle, or an irregular shape.

[0122] For example, the shape of the optical waveguide sheet 100 may include a circle, an ellipse, a rounded rectangle, or an irregular shape, etc., which is not specifically limited here.

[0123] In some embodiments, the horizontal bisector of the optical waveguide sheet 100 includes one of a horizontal line corresponding to the center point of the optical waveguide sheet 100 and a bisector in the horizontal direction. Thus, the horizontal bisector of the outcoupling region 30 can be accurately determined even when the optical waveguide sheet 100 is irregular in shape.

[0124] The horizontal bisector of the optical waveguide sheet 100 may be a bisector in the horizontal direction of the optical waveguide sheet 100 ; the bisector in the horizontal direction of the optical waveguide sheet 100 is equidistant from the upper side and the lower side of the optical waveguide sheet 100 .

[0125] Specifically, if the horizontal bisector of the optical waveguide plate 100 is relatively easy to determine, for example, if the shape of the optical waveguide plate 100 is regular, the center point of the optical waveguide plate 100 can be quickly determined through simple calculations. For example, if the shape of the optical waveguide plate 100 is irregular, the center point can be determined by finding the center point of the circumscribed circle of the optical waveguide plate 100, and the horizontal line passing through the center point is used as the horizontal bisector of the optical waveguide plate 100.

[0126] Specifically, if it is difficult to determine the center point of the optical waveguide plate 100, for example, the shape of the optical waveguide plate 100 is irregular, the horizontal bisector of the optical waveguide plate 100 can be found by determining a horizontal line with equal distances between the upper and lower edges of the optical waveguide plate 100.

[0127] For example, if the upper side line or the lower side line is an irregular line, such as an arc line, the horizontal bisector of the optical waveguide sheet 100 can be found by determining the midpoint of the upper side line and the lower side line, and then finding a horizontal line that is equidistant from the midpoint of the upper side line and the midpoint of the lower side line.

[0128] The horizontal direction may be the x-axis direction, that is, the length direction of the outcoupling region 30 .

[0129] As shown in FIG15( a ), for example, if the shape of the optical waveguide plate 100 is irregular, the tangent line of the upper edge of the optical waveguide plate 100 and the tangent line of the lower edge of the optical waveguide plate 100 in the horizontal direction can be determined first, and then a horizontal line with an equal distance from the two tangent lines can be found to determine the horizontal bisector of the optical waveguide plate 100.

[0130] As shown in FIG. 15( b ), for example, if the shape of the optical waveguide plate 100 is circular, the center of the circle can be determined, and the horizontal diameter can be used as the horizontal bisector of the optical waveguide plate 100 .

[0131] As shown in FIG15( c ), for example, if the shape of the optical waveguide plate 100 is a rounded rectangle, the horizontal bisector of the optical waveguide plate 100 can be found by determining the midpoint of the upper and lower edges and then finding a horizontal line that is equidistant from the midpoint of the upper and lower edges.

[0132] Please refer to FIG16 , which is a schematic structural diagram of a frame provided in an embodiment of the present application.

[0133] As shown in FIG. 16 , the eyeglass frame 1000 includes a light emitting assembly 200 , an eyeglass frame 300 and an optical waveguide sheet 100 .

[0134] The light emitting assembly 200 is used to emit display light and enable the coupling region 20 in the optical waveguide plate 100 to receive the display light. The optical waveguide plate 100 can be fixedly installed in the mirror frame 300 .

[0135] Specifically, the optical waveguide sheet 100 can be configured with reference to the examples in Figures 1 to 15. For example, the optical waveguide sheet 100 includes the waveguide substrate 10, the coupling-in region 20, and the coupling-out region 30 described in the above embodiment. The specific configuration of the optical waveguide sheet 100 can refer to the corresponding embodiment described in the specification of this application, and this embodiment will not be repeated here.

[0136] The frame 1000 provided in the present application can move the out-coupling area 30 out of the central area of ​​the main field of view of the smart glasses by changing the position of the out-coupling area 30 on the optical waveguide plate 100, thereby effectively avoiding the diffraction rainbow stripes appearing in the wearer's main field of view. At the same time, it can also ensure that the AR imaging function is realized in the effective area, so that the wearer can clearly and accurately see the display information of the out-coupling area 30 even if he slightly raises his eyes.

[0137] Please refer to Figure 17, which is a structural diagram of smart glasses provided in an embodiment of the present application.

[0138] As shown in FIG. 17 , smart glasses 2000 include the optical waveguide sheet 100 .

[0139] Specifically, the optical waveguide sheet 100 can be configured with reference to the examples in Figures 1 to 12. For example, the optical waveguide sheet 100 includes the waveguide substrate 10, the coupling-in region 20, and the coupling-out region 30 described in the above embodiment. The specific configuration of the optical waveguide sheet 100 can refer to the corresponding embodiment described in the specification of this application, and this embodiment will not be repeated here.

[0140] The smart glasses 2000 provided in the present application can move the out-coupling region 30 out of the center area of ​​the main field of view of the smart glasses by changing the position of the out-coupling region 30 on the optical waveguide sheet 100, thereby effectively avoiding the diffraction rainbow stripes appearing in the wearer's main field of view. At the same time, it can also ensure that the AR imaging function is realized in the effective area, so that the wearer can clearly and accurately see the display information of the out-coupling region 30 even when slightly raising his eyes.

[0141] The above are only specific embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and such modifications or substitutions should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An optical waveguide sheet, characterized in that: Applied to smart glasses, the optical waveguide sheet comprises: waveguide substrate; An incoupling region and an outcoupling region are provided in the waveguide substrate, the incoupling region is used to couple light into the waveguide substrate, and the outcoupling region is used to couple out light propagating in the waveguide substrate; The bottom edge of the outcoupling region is located on the upper side of the horizontal bisector of the optical waveguide plate; or, all or part of the bottom edge of the outcoupling region is flush with the horizontal bisector of the optical waveguide plate.

2. The optical waveguide sheet according to claim 1, wherein: The distance between the bottom edge of the outcoupling region and the horizontal bisector of the optical waveguide plate is greater than or equal to 2 mm.

3. The optical waveguide sheet according to claim 1, wherein: The outcoupling region is in the shape of a rectangle or a rounded rectangle.

4. The optical waveguide sheet according to claim 1, wherein: The length of the outcoupling region is greater than or equal to twice the width of the outcoupling region, the length is the distance of the outcoupling region in the horizontal direction, and the width is the distance of the outcoupling region in the vertical direction.

5. The optical waveguide sheet according to claim 4, characterized in that: The length of the outcoupling region is greater than or equal to 3 times the width of the outcoupling region.

6. The optical waveguide sheet according to claim 1, wherein: The waveguide substrate further comprises: A grating layer is provided on the waveguide substrate to form the coupling-in region and / or the coupling-out region.

7. The optical waveguide sheet according to claim 6, characterized in that The thickness of the grating layer ranges from 10 nanometers to 500 nanometers.

8. The optical waveguide sheet according to claim 6, wherein: The optical waveguide sheet further comprises: A first anti-reflection film is arranged on the surface of the grating layer.

9. The optical waveguide sheet according to claim 8, characterized in that: The first anti-reflection film is disposed around the coupling-in region and the coupling-out region, and the first anti-reflection film does not cover the coupling-in region and the coupling-out region.

10. The optical waveguide sheet according to claim 8, wherein The first antireflection film covers the coupling-in region and the coupling-out region.

11. The optical waveguide sheet according to claim 8, wherein The optical waveguide sheet further comprises: A second anti-reflection film is disposed on the second surface of the waveguide substrate.

12. The optical waveguide sheet according to claim 11, wherein: The optical waveguide sheet further comprises: A first protective lens is arranged on a side away from the wearer, and the first protective lens is stacked with the grating layer; The second protective lens is arranged on the side close to the wearer, and the second protective lens is stacked with the second surface of the waveguide substrate.

13. The optical waveguide sheet according to claim 12, wherein: The optical waveguide sheet further comprises: A third anti-reflection film, the third anti-reflection film is arranged on the first surface of the first protective lens; and / or, a fourth anti-reflection film, the fourth anti-reflection film being arranged on the second surface of the first protective lens; and / or, a fifth anti-reflection film, wherein the fifth anti-reflection film is disposed on the first surface of the second protective lens; and / or, A sixth anti-reflection film is arranged on the second surface of the second protective lens.

14. The optical waveguide sheet according to claim 12 or 13, characterized in that: The material refractive index of the waveguide substrate, the grating layer, the first protective glass and the second protective glass is lower than or equal to 2.

15. The optical waveguide sheet according to claim 1, wherein: The shape of the optical waveguide sheet includes a circle, an ellipse, a rounded rectangle or an irregular shape.

16. The optical waveguide sheet according to claim 1, wherein: The horizontal bisector of the optical waveguide sheet includes one of a horizontal line corresponding to the center point of the optical waveguide sheet and a bisector in the horizontal direction.

17. A glasses frame, characterized in that: It comprises a light-emitting component, a mirror frame and the optical waveguide sheet as claimed in any one of claims 1 to 16, wherein the light-emitting component is used to emit display light; and the optical waveguide sheet is fixedly installed in the mirror frame.

18. A pair of smart glasses, characterized in that: The smart glasses include the optical waveguide sheet according to any one of claims 1 to 16.

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