Flexible film and intelligent glasses

Abstract

The invention discloses a flexible film and intelligent glasses, and belongs to the technical field of electronics. The flexible film includes: a base layer; the grating layer is arranged on one side of the substrate layer; the first protection layer is arranged on the side, away from the substrate layer, of the grating layer; wherein the grating layer comprises at least one diffraction grating, the diffraction grating comprises a plurality of sawtooth-shaped notch grooves, the inclination angles of the notch grooves meet the requirement that the diffraction grating diffracts incident parallel light into a bright line, and the extension direction of the bright line is the same as the grating direction of the diffraction grating.

Description

Technical Field

[0001] The present application belongs to the field of electronic technology, and specifically relates to a flexible film and smart glasses. Background Art

[0002] Waveguide optical structure is a type of optical component designed based on the principle of total internal reflection. It is used to efficiently transmit and control light waves at the micron or nanometer scale. It is widely used in AR (Augmented Reality), VR (Virtual Reality), integrated optics, communications and other fields.

[0003] Currently, waveguide optical structures are usually based on waveguide materials and are realized through grating manufacturing processes and multi-layer stacking processes.

[0004] However, the waveguide optical structure implemented by the above solution has a heavy design structure, and the optical path of the waveguide optical structure is complex. It is difficult to match the waveguide display with the diopter calibration. In addition, the waveguide materials, grating production and multi-layer stacking process are expensive, and the cost of the waveguide optical structure is high. Summary of the Invention

[0005] The purpose of the embodiments of the present application is to provide a flexible film and smart glasses that can simplify the design structure of light wave transmission control, reduce the cost of light wave transmission control, and simplify the optical path of light wave transmission control, thereby facilitating matching between waveguide display and diopter calibration.

[0006] In a first aspect, an embodiment of the present application provides a flexible film, comprising: a base layer; a grating layer, arranged on one side of the base layer; and a first protective layer, arranged on a side of the grating layer away from the base layer; wherein the grating layer includes at least one diffraction grating, the diffraction grating includes a plurality of serrated grooves, and the inclination angle of the grooves satisfies that the diffraction grating diffracts incident parallel light into a bright line, and the extension direction of the bright line is the same as the grating direction of the diffraction grating.

[0007] In a second aspect, an embodiment of the present application provides a pair of smart glasses, comprising: a frame; a lens, arranged in the frame, with at least one flexible film as in the first aspect adhered to the lens, the at least one flexible film comprising a plurality of groups of gratings, the plurality of groups of gratings corresponding to the vertex area and the center area of ​​the lens, respectively, each group of gratings comprising a first grating and a second grating arranged to intersect, the grating direction of the first grating being a first direction, and the grating direction of the second grating being a second direction; temples connected to the frame; a collimated light source module, arranged on the temples, the collimated light source module being used to emit parallel light to the lens, the plurality of groups of gratings in the at least one flexible film being used to diffract the parallel light into a plurality of groups of bright lines, each group of bright lines comprising a first bright line extending along a first direction and a second bright line extending along a second direction, the first bright line and the second bright line in each group of bright lines intersecting.

[0008] The flexible film provided in the embodiment of the present application includes a base layer, a grating layer and a first protective layer. The grating layer is arranged on one side of the base layer; the first protective layer is arranged on the side of the grating layer away from the base layer. Furthermore, the grating layer includes at least one diffraction grating, and the diffraction grating includes a plurality of serrated grooves. The inclination angle of the grooves satisfies that the diffraction grating diffracts the incident parallel light into a bright line, and the extension direction of the bright line is the same as the grating direction of the diffraction grating. Through the above-mentioned flexible film, a grating layer including at least one diffraction grating is provided, and the diffraction grating diffracts the incident parallel light into a bright line. In this way, the transmission control of light waves can be achieved only by providing a diffraction grating in the flexible film, which simplifies the design structure of the light wave transmission control, reduces the cost of the light wave transmission control, and simplifies the optical path of the light wave transmission control, facilitating the matching between the waveguide display and the diopter calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is one of the structural schematic diagrams of the flexible film provided in an embodiment of the present application;

[0010] Figure 2 The second structural diagram of the flexible film provided in the embodiment of the present application;

[0011] Figure 3 One of the structural diagrams of the grating layer provided in an embodiment of the present application;

[0012] Figure 4 The second structural diagram of the grating layer provided in the embodiment of the present application;

[0013] Figure 5 The third structural diagram of the flexible film provided in the embodiment of the present application;

[0014] Figure 6 A diagram showing the working principle of the blazed grating provided in an embodiment of the present application;

[0015] Figure 7 is a parameter relationship diagram of a single optical imaging surface in the related art;

[0016] Figure 8 A schematic diagram of a display of a viewfinder provided in an embodiment of the present application;

[0017] Figure 9 A structural block diagram of the smart glasses provided in an embodiment of the present application;

[0018] Figure 10 A schematic diagram of the structure of the smart glasses provided in an embodiment of the present application;

[0019] Figure 11 This is a schematic structural diagram of the collimated light source module provided in an embodiment of the present application.

[0020] Reference numerals:

[0021] 100 flexible film, 102 base layer, 104 grating layer, 106 groove, 108 first grating, 110 second grating, 112 bonding layer, 114 first protective layer, 116 second protective layer, 118 liquid crystal layer, 120 diffraction grating, 122 grating group, 200 smart glasses, 202 frame, 204 lens, 206 temple, 208 collimated light source module, 210 light source assembly, 212 lens assembly, 214 drive assembly, 216 controller, 218 photosensor. DETAILED DESCRIPTION

[0022] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0023] The features of the terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0024] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, or electrical connections; direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0025] The following combination Figures 1-11 The flexible film and smart glasses according to the embodiments of the present application are described in detail.

[0026] like Figure 1 As shown, an embodiment of the present application provides a flexible film 100 , wherein the flexible film 100 includes a base layer 102 , a first protective layer 114 and a grating layer 104 .

[0027] Among them, such as Figure 1 As shown, the grating layer 104 is disposed on one side of the base layer 102 , and the base layer 102 is a supporting layer for the grating layer 104 .

[0028] Furthermore, the transmittance of the base layer 102 is greater than or equal to a first threshold.

[0029] Furthermore, the base layer 102 has the characteristics of transparency and flexibility. As for the specific value of the first threshold, those skilled in the art can select it according to actual conditions, such as selecting the first threshold as 90%, which is not specifically limited here.

[0030] In actual applications, the material of the base layer 102 may be transparent PET (Polyethylene Terephthalate) or PI (Polyimide), and the thickness of the base layer 102 may be 10 μm to 50 μm.

[0031] Furthermore, if Figure 3 As shown, the grating layer 104 includes at least one diffraction grating 120 .

[0032] Among them, such as Figure 6 As shown, the diffraction grating 120 includes a plurality of sawtooth grooves 106 , and the inclination angle of the grooves 106 satisfies the diffraction grating 120 to diffract the incident parallel light into a bright line, and the extension direction of the bright line is the same as the grating direction of the diffraction grating 120 .

[0033] In actual application, the material of the grating layer 104 may be UV (Ultraviolet) photoresist, and the thickness of the grating layer 104 may be 400 nm to 600 nm. The grating layer 104 may achieve high-efficiency first-order diffraction.

[0034] In actual application, the diffraction grating 120 can be specifically a blazed grating. The angle between the groove slope of the blazed grating and the grating plane is the inclination angle of the groove 106, also known as the blaze angle, which determines the blaze wavelength of the grating. The blaze wavelength is the wavelength with the highest grating diffraction efficiency. By controlling the inclination angle of the groove 106, the light wave can meet the "mirror reflection condition" at a specific diffraction order, thereby concentrating most of the light energy to a specific diffraction order.

[0035] It can be understood that for the diffraction of an equally spaced grating, the grating equation is as shown in the following equation (1), which describes the relationship between the incident angle of the incident light and the diffraction angles of different diffraction orders when the wavelength of the incident light is determined.

[0036] d(sinα±sinβ) =mλ(m=0, ±1, ±2, ...) (1)

[0037] Among them, α is the incident angle, β is the diffraction angle, d is the grating constant, m is the diffraction order, and λ is the diffraction wavelength, that is, the wavelength of the incident light.

[0038] Furthermore, it can be seen from the grating equation that when the diffraction order is 0, incident light of any wavelength will be diffracted in the same direction. Therefore, the 0th order of grating diffraction has no dispersion effect and cannot split the incident light. If the grating is to be used to split and disperse the incident light, a high diffraction order of the grating must be used.

[0039] Furthermore, the diffraction diagram of the blazed grating is shown as Figure 6 As shown in Figure 1, compared with rectangular gratings, blazed gratings can separate the interference order 0 and the diffraction central principal pole, so that the interference order 0 moves to a higher order. It is a typical "unidirectional high-energy directional emission" grating. The interference principal maximum of the blazed grating is determined by the grating equation. Moving the principal maximum to the m diffraction order requires satisfying the following formula (2):

[0040] 2dsinθsinα=mλ (2)

[0041] Where θ is the blaze angle, which is the inclination angle of the blazed grating's grooves relative to the substrate normal. A primary maximum is a prominent, concentrated bright fringe in the diffraction pattern. By adjusting the blaze angle, the diffraction efficiency of incident light with a wavelength of λ can be maximized in a specific direction, such as the m=+1 order.

[0042] In actual applications, the diffraction grating 120 may also adopt other high-efficiency gratings, which is not specifically limited here.

[0043] Furthermore, if Figure 1 As shown, the first protection layer 114 is disposed on a side of the grating layer 104 away from the base layer 102 .

[0044] Specifically, the first protective layer 114 is a surface protective layer, which is used to provide protection against scratches, fingerprints, and dust.

[0045] In actual application, the material of the first protective layer 114 may be SiO 2 (silicon dioxide) or UV-curable acrylic resin, and the thickness of the first protective layer 114 may be 50 nm to 200 nm.

[0046] According to an embodiment of the present application, the flexible film 100 includes a base layer 102, a first protective layer 114, and a grating layer 104. The grating layer 104 is disposed on one side of the base layer 102; the first protective layer 114 is disposed on a side of the grating layer 104 away from the base layer 102. Furthermore, the grating layer 104 includes at least one diffraction grating 120, which includes a plurality of sawtooth-shaped grooves 106. The grooves 106 are tilted at an angle such that the diffraction grating 120 diffracts incident parallel light into a bright line, with the bright line extending in the same direction as the grating direction of the diffraction grating 120. The flexible film 100 described above is provided with a grating layer 104 including at least one diffraction grating 120, and the diffraction grating 120 diffracts incident parallel light into a bright line. In this way, lightwave transmission control can be achieved simply by providing the diffraction grating 120 in the flexible film 100, thereby simplifying the design structure of the lightwave transmission control, reducing the cost of the lightwave transmission control, and simplifying the optical path of the lightwave transmission control, thereby facilitating matching between waveguide display and diopter calibration.

[0047] According to some embodiments of the present application, optionally, as Figure 4 As shown, the grating layer 104 includes at least one grating group 122 .

[0048] Each grating group 122 includes a first grating 108 and a second grating 110 .

[0049] Furthermore, the grating direction of the first grating 108 is a first direction, the grating direction of the second grating 110 is a second direction, and the first direction intersects with the second direction.

[0050] Furthermore, the number of the first grating 108 and the second grating 110 can be one or more. If the number of the first grating 108 and the second grating 110 is more than one, in each grating group 122, every two first gratings 108 and second gratings 110 intersect with each other.

[0051] On this basis, the incident parallel light can be diffracted into a first bright line and a second bright line intersecting each other by a grating set 122. The first bright line extends along a first direction, and the second bright line extends along a second direction.

[0052] According to the flexible film 100 of the embodiment of the present application, the grating layer 104 includes at least one first grating 108 and at least one second grating 110. The grating direction of the first grating 108 is a first direction, and the grating direction of the second grating 110 is a second direction. The first direction and the second direction intersect, and every two first gratings 108 and second gratings 110 intersect. In this way, a set of intersecting bright lines can be diffracted through a single flexible film 100, facilitating the subsequent customization of different intersecting bright line combinations by combining and stacking flexible films 100.

[0053] According to some embodiments of the present application, optionally, as Figure 1 As shown, the flexible film 100 further includes a conformable layer 112 .

[0054] Among them, such as Figure 1 As shown, the conforming layer 112 is disposed on the other side of the base layer 102 .

[0055] Furthermore, the laminating layer 112 is used to achieve seamless assembly and disassembly of the flexible film 100 and other smooth surfaces such as lenses.

[0056] In actual application, the material of the bonding layer 112 can be optical grade acrylic pressure-sensitive adhesive or silicone-based adhesive. The thickness of the bonding layer 112 can be 5 μm to 20 μm. The bonding layer 112 supports repeated bonding and can be replaced without leaving any adhesive.

[0057] Based on the bonding layer 112 , the flexible film 100 can be attached to the surface of various lenses through self-adhesive or electrostatic bonding processes, supporting manual replacement by users.

[0058] According to the flexible film 100 of the embodiment of the present application, the flexible film 100 further includes a bonding layer. Bonding layer 112 is disposed on the other side of base layer 102 and is used to achieve seamless assembly and disassembly of the flexible film 100 and the lens. Bonding layer 112 thus enables seamless assembly and disassembly of the flexible film 100, facilitating manual replacement by the user.

[0059] According to some embodiments of the present application, optionally, as Figure 2 As shown, the flexible film 100 further includes a second protective layer 116 .

[0060] Among them, such as Figure 2 As shown, the second protective layer 116 is detachably disposed on a side of the first protective layer 114 away from the grating layer 104 .

[0061] Furthermore, the hardness of the second protective layer 116 is greater than the hardness of the first protective layer 114 .

[0062] Specifically, the second protective layer 116 is a hard protective layer, which is used to provide secondary protection for the flexible film 100 , can withstand external wipes and collisions, and protect the inner microstructure of the flexible film 100 from mechanical pressure.

[0063] In actual application, the user can realize the second protective layer 116 of the flexible film 100 by snapping on a transparent cover of his / her choice.

[0064] Furthermore, the second protective layer 116 can be seamlessly installed and removed compared to the first protective layer 114. When the user actually uses the flexible film 100, such as when the user attaches the flexible film 100 to the lenses of smart glasses, the user can choose to keep or tear off the second protective layer 116 of the flexible film 100 according to their needs.

[0065] The flexible film 100 according to an embodiment of the present application further includes a second protective layer 116. The second protective layer 116 is detachably disposed on a side of the first protective layer 114 away from the grating layer 104. The second protective layer 116 has a greater hardness than the first protective layer 114. Thus, the second protective layer 116 provides secondary protection for the flexible film 100, protecting the inner microstructure of the flexible film 100 from mechanical stress. Furthermore, the detachable second protective layer 116 can meet various user needs.

[0066] According to some embodiments of the present application, optionally, as Figure 5 As shown, the flexible film 100 further includes a liquid crystal layer 118 .

[0067] The liquid crystal layer 118 is disposed between the grating layer 104 and the first protection layer 114 .

[0068] Furthermore, the liquid crystal layer 118 is used to sense environmental information of the flexible film 100 and adjust its own refraction parameters for the bright line according to the environmental information to adjust the display position of the bright line.

[0069] That is, the flexible film 100 provided in the embodiment of the present application, by embedding the liquid crystal layer 118 in the flexible film 100, enables the flexible film 100 to adjust the display position of the bright line obtained by diffraction in real time based on electric field changes or thermal changes.

[0070] The above-mentioned environmental information includes at least one of the following items or a combination thereof: electric field information, temperature information.

[0071] On this basis, when the flexible film 100 is applied to smart glasses to realize the display position of the bright line when the smart glasses display the viewfinder, the shape of the displayed viewfinder can be adjusted based on the liquid crystal layer 118, and the viewfinder display can even be controlled to be turned on or off.

[0072] Specifically, the flexible film 100 provided in the embodiment of the present application has a fixed grating structure in the grating layer 104, that is, the flexible film 100 has a fixed diffraction pattern structure. When the flexible film 100 is applied to smart glasses, the customized diffraction pattern structure can form a fixed and stable viewfinder on the user's retina, facilitating real-time interaction with AI (Artificial Intelligence) recognition algorithms to assist in scene framing. On this basis, with the help of the liquid crystal layer 118 in the flexible film 100, different display forms of viewfinders can be switched in real time based on electric field changes or thermal changes, or the display of the viewfinder can be turned on and off, enriching the diversity and fun of the viewfinder display.

[0073] According to an embodiment of the present application, the flexible film 100 further includes a liquid crystal layer 118 disposed between the grating layer 104 and the first protective layer 114. Liquid crystal layer 118 senses environmental information about the flexible film 100 and adjusts its refractive parameters for the bright line based on this environmental information, thereby adjusting the displayed position of the bright line. Environmental information includes at least one of the following, or a combination thereof: electric field information and temperature information. In this way, the flexible film 100 can adjust the displayed position of the diffracted bright line in real time based on changes in the electric field or thermally induced changes, enriching the diversity and interest of the diffraction pattern display.

[0074] According to some embodiments of the present application, optionally, the first direction and the second direction are perpendicular to each other.

[0075] One of the first direction and the second direction is a horizontal direction, and the other is a vertical direction.

[0076] That is, in the flexible film 100 provided in the embodiment of the present application, each grating group 122 is superimposed with two groups of linear phase diffraction blazed gratings, one group of which extends in the horizontal direction and the other group of which extends in the vertical direction. After first-order diffraction through the grating group 122, a bright line can be projected in the horizontal direction and the vertical direction respectively.

[0077] In actual application, Figure 4 As shown, for each grating group 122, every two first gratings 108 and second gratings 110 in the grating group 122 can intersect vertically in a "cross", "right angle", "T" or other shapes, so that through grating diffraction, one grating group 122 can obtain a group of bright lines in the shape of a "cross" or "right angle", which is convenient for subsequent customization of different diffraction patterns by combining and superimposing the flexible film 100.

[0078] Furthermore, the grating period, grating depth, inclination angle of the groove 106 and grating width of different diffraction gratings 120, namely the first grating 108 and the second grating 110, are consistent to ensure that the diffracted first bright line and the second bright line can be superimposed into a "cross" or "right angle".

[0079] The grating period d can be calculated by taking the desired framing angle of the flexible film 100 on the user's retina when applied to smart glasses as the blaze angle θ, and then combining it with the wavelength λ of the incident light using the diffraction formula d sinθ = λ. The grating depth and tilt angle can be calculated by optimizing the first-order diffraction efficiency of the blazed grating to 85% through simulation, thereby obtaining the final parameters of the blazed grating, including the tilt angle, duty cycle, and grating depth.

[0080] According to the flexible film 100 of the embodiment of the present application, the first direction and the second direction are perpendicular to each other, and the grating period, grating depth and grating width of the different diffraction gratings 120 are consistent, thereby improving the display effect of the diffraction bright line.

[0081] According to some embodiments of the present application, optionally, as Figure 4 As shown, at least one first grating 108 and at least one second grating 110 cover a partial area of ​​the grating layer 104 .

[0082] In actual application, the flexible film 100 can be in the shape of a right-angled rectangle or a rounded rectangle, and each grating group 122 can be set in the four vertex areas or the center area of ​​the flexible film 100, so that different diffraction patterns can be customized by subsequently combining and superimposing the flexible film 100.

[0083] In one possible embodiment, Figure 4 As shown, the grating layer 104 includes a plurality of grating groups 122 . Each grating group 122 includes a plurality of first gratings 108 and a plurality of second gratings 110 . The plurality of grating groups 122 are respectively disposed in four corner regions and a central region of the flexible film 100 .

[0084] According to the flexible film 100 of the embodiment of the present application, at least one first grating 108 and at least one second grating 110 cover a portion of the grating layer 104. This facilitates subsequent customization of different diffraction patterns by combining and stacking the flexible film 100.

[0085] According to some embodiments of the present application, optionally, the diffraction grating 120 is manufactured by a nanoimprint process.

[0086] Furthermore, the diffraction grating 120 can also be manufactured by a photolithography process. Specifically, the diffraction grating 120 is manufactured by performing double-beam exposure on a photosensitive material, which is used to adjust the refractive index of the photosensitive material so that the photosensitive material has the optical properties of a grating.

[0087] In the flexible film 100 of the present embodiment, the diffraction grating 120 is fabricated using a nanoimprint process. Alternatively, the diffraction grating 120 is fabricated using a photosensitive material through dual-beam exposure, which adjusts the refractive index of the photosensitive material to impart the optical properties of a grating. This allows the production cost of a single flexible film 100 to be significantly lower than that of a waveguide, reducing the cost of controlling lightwave transmission.

[0088] According to some embodiments of the present application, optionally, as Figure 9 As shown, the embodiment of the present application further provides a smart glasses 200. Figure 9 As shown, the smart glasses 200 include a frame 202 , lenses 204 , temples 206 , and a collimated light source module 208 .

[0089] The lens 204 is disposed in the frame 202 , and at least one flexible film 100 as described in any of the above embodiments is adhered to the lens 204 .

[0090] The smart glasses 200 provided in the embodiment of the present application include the flexible film 100 in any of the above embodiments and can achieve the same technical effects. To avoid repetition, they are not described here.

[0091] In actual application, at least one flexible film 100 can be attached to the outer side of the lens 204 . The outer side of the lens 204 is closer to a plane, and the influence of different refractive curvatures on the deformation of the grating structure in the flexible film 100 is smaller.

[0092] Furthermore, after at least one flexible film 100 is stacked, it includes a total of multiple groups of gratings, and the multiple groups of gratings correspond to the vertex area and the center area of ​​the lens 204 respectively. Each group of gratings includes a first grating and a second grating arranged to intersect. The grating direction of the first grating is a first direction, and the grating direction of the second grating is a second direction, and the first direction and the second direction intersect.

[0093] In actual applications, each flexible film 100 may include only a first grating with a grating orientation in a first direction, may include only a second grating with a grating orientation in a second direction, or may include both the first and second gratings. Therefore, when a user desires to display a viewfinder on the smart glasses 200, the user may attach flexible films 100 including both the first and second gratings to the top corners and center of the lens 204, respectively. Alternatively, the user may attach both flexible films 100 including only the first grating and flexible films including only the second grating to the top corners and center of the lens 204, to meet the diffraction structure requirements for displaying the viewfinder.

[0094] Furthermore, the temples 206 are connected to the frame 202 .

[0095] Furthermore, the collimated light source module 208 is disposed on the temple 206 .

[0096] Furthermore, the collimated light source module 208 is configured to emit parallel light toward the lens 204 .

[0097] Furthermore, the multiple groups of gratings in at least one flexible film 100 are used to diffract the parallel light into multiple groups of bright lines, each group of bright lines includes a first bright line extending along a first direction and a second bright line extending along a second direction, and the first bright line and the second bright line in each group of bright lines intersect, thereby forming a Figure 8 The "cross and right angle" framing frame shown.

[0098] Understandably, with the widespread adoption of wearable camera devices, smart glasses are becoming a new favorite in both the industry and consumer markets. When users use smart glasses to capture videos or photos, they often want to be able to visually see the framing area in real time to improve image accuracy.

[0099] At present, the viewfinder display solutions of smart shooting glasses mostly use waveguide optical structures, which refract micro-light sources into the wearer's field of view through waveguides to achieve real-time superposition of the viewfinder in the wearer's field of view.

[0100] However, in the related art, the optical path of the implementation scheme of the waveguide optical structure on the smart shooting glasses is complex, and there are many shortcomings in actual use: the waveguide materials, grating production and multi-layer stacking process are expensive and the cost is high; the matching of the refractive power of the waveguide display and the main lens is complex. If the user needs to wear myopia or hyperopia glasses, they need to buy corrective lenses or perform complex calibration, and the refractive correction operation is complicated; the multi-layer waveguide structure makes the glasses frame thick, which affects the wearing effect.

[0101] The smart glasses 200 provided in the embodiments of the present application employ the flexible film 100 of any of the aforementioned embodiments. The flexible film 100 diffracts multiple bright lines to display a viewfinder of the smart glasses 200. This simplifies the optical path and reduces manufacturing costs. Furthermore, the flexible film 100 is designed to be thin, light, and flexible, allowing it to be applied to various lenses, such as those for myopia, hyperopia, or plano. This eliminates the need to readjust the lens' diopter or obtain additional corrective lenses, making refractive correction easier.

[0102] In summary, the frame display solution provided in the embodiments of the present application achieves the display of a fixed frame pattern by fabricating a diffractive structure on a transparent flexible film 100 and applying the flexible film 100 to smart glasses 200. Compared to traditional waveguide-based frame display solutions, the frame display solution provided in the embodiments of the present application is lightweight, comfortable, and cost-effective. Furthermore, the flexible film 100 can be attached to any refractive lens, expanding the range of people who can wear smart glasses. Furthermore, the frame pattern can be flexibly customized to meet the user's personalized needs.

[0103] It should be noted that the smart glasses 200 in the embodiments of the present application include AR glasses, VR glasses, smart photography glasses, etc., and are not specifically limited here.

[0104] According to some embodiments of the present application, optionally, each group of gratings includes multiple first gratings and multiple second gratings, every two first gratings are parallel to each other, every two second gratings are parallel to each other, and every two first gratings intersect with each other.

[0105] It is understandable that FOV (Field of View) and EYEBOX (exit pupil range) are two important parameters for near-eye display. Among them, FOV is the angular range of the world that can be observed by the human eye or devices such as cameras and VR headsets. Furthermore, EYEBOX is a three-dimensional conical space between the eyeball and the optical module in a near-eye display device such as a VR headset or an AR headset. Within this area, the user can see a clear, undistorted complete image. Beyond this area, image blur, color distortion or field of view obstruction may occur. A larger EYEBOX can allow the eyeball to move naturally, reduce eye fatigue, and is also compatible with a wider range of pupil distances.

[0106] Furthermore, it can be understood that in plane optics, the relationship between FOV, EYEBOX and exit pupil distance is as follows: Figure 7As shown, s represents the width of the optical imaging surface in plane optics, b represents EYEBOX, v represents FOV, r represents the exit pupil distance, and s = b + 2 × r × tan (v / 2). That is, in plane optics, the FOV and EYEBOX of a single optical imaging surface are contradictory. For diffraction imaging based on a single grating structure, when the FOV is 18° and the exit pupil distance r = 20mm, it can be calculated that the EYEBOX is only 1.68mm. On this basis, AR glasses based on intraretinal diffraction imaging usually need to be used in conjunction with pupil expansion and eye tracking.

[0107] Therefore, in the smart glasses 200 provided in the embodiments of the present application, each grating set includes multiple sets of intersecting first and second gratings, achieving eyebox expansion through the overlapping of multiple grating sets. In this case, as long as the energy distribution between the higher-order diffraction and zero-order diffraction of the first and second gratings is clearly separated, no matter how the user's eyes move, only the first bright line in the first direction and the second bright line in the second direction will be projected onto the user's retina, without the appearance of multiple images of the same bright line.

[0108] For example, using a miniature collimated light source with an aperture of 12.5mm and an 80% grating coverage, the eyebox is 10mm. At this point, the user can still see the entire viewfinder if they move their pupil left or right or up and down within a range of ±5mm.

[0109] According to the smart glasses 200 of the present embodiment, each set of gratings includes multiple first gratings and multiple second gratings. Each pair of first gratings is parallel to each other, each pair of second gratings is parallel to each other, and each pair of first gratings and second gratings intersects. This expansion of the exit pupil range is achieved by covering multiple sets of gratings, allowing the user to fully see the viewfinder when moving their eyes within a certain range, without ghosting.

[0110] According to some embodiments of the present application, optionally, as Figure 9 、 Figure 10 and Figure 11 As shown, the collimated light source module 208 includes a light source assembly 210 and a lens assembly 212 .

[0111] The light source assembly 210 is disposed on the temple 206 .

[0112] Furthermore, the light source assembly 210 is used to emit divergent light sources.

[0113] In actual application, the light source component 210 can be a monochromatic or multi-color light source, such as a monochromatic LED (Light-Emitting Diode), a narrow-band LED, and a VCSEL (Vertical-Cavity Surface-Emitting Laser), etc., to ensure the calculation accuracy of the diffraction angle and the imaging clarity.

[0114] Furthermore, the divergence angle of the divergent light source emitted by the light source assembly 210 is controlled within the range of ±30°, so as to cooperate with the rear lens assembly 212 to emit parallel light toward the lens 204 .

[0115] Furthermore, the size of the light source assembly 210 can satisfy the following requirements: half of the height and half of the width are less than 20 nm, so as to be mounted on the smart glasses 200 .

[0116] In actual use, the light source assembly 210 can be selectively set to an on or off state. When the light source assembly 210 is off, the viewfinder is not displayed in the field of view of the smart glasses 200. In this way, compared with the problem of high power consumption caused by the continuous operation of the optical engine in traditional solutions, the viewfinder display method of the smart glasses 200 in this embodiment of the application has lower power consumption and increases the battery life of the smart glasses 200.

[0117] That is, the smart glasses 200 provided in the embodiment of the present application achieve real-time, low-power, and low-cost viewfinder frame superposition by setting a high-efficiency grating on a flexible transparent substrate, and are compatible with various types of refractive lenses.

[0118] Furthermore, the lens assembly 212 is disposed on the temple 206 .

[0119] Furthermore, the lens assembly 212 is used to convert the divergent light emitted by the light source assembly 210 into parallel light and then emit it to the lens 204 .

[0120] Specifically, the divergent light emitted by the light source assembly 210 is converted into parallel light after passing through the lens assembly 212 and is incident on the flexible film 100 attached to the lens 204. The flexible film 100 diffracts the incident parallel light, forming a viewfinder with a central cross and four right-angle structures on the retina of the wearer of the smart glasses 200.

[0121] Furthermore, the focal length of the lens assembly 212 depends on the size of the light source assembly 210 , and the size of the light spot ultimately formed by the lens assembly 212 needs to match the area of ​​the flexible film 100 to ensure that the entire structural design area of ​​the flexible film 100 can be illuminated by parallel light.

[0122] In actual application, the lens assembly 212 may be a collimating lens.

[0123] Furthermore, in order to ensure that the edges of the viewfinder pattern displayed by the smart glasses 200 are not deformed, an aspherical lens or a microprism array can be set between the light source assembly 210 and the lens assembly 212 to further correct the divergent light source emitted by the light source assembly 210.

[0124] According to some embodiments of the present application, optionally, as Figure 9 As shown, the smart glasses 200 further include a driving component 214 , a controller 216 , and a light-sensitive sensor 218 .

[0125] The driving assembly 214 is connected to the light source assembly 210 .

[0126] Furthermore, the controller 216 is connected to the driving assembly 214 .

[0127] Furthermore, the photosensor 218 is connected to the controller 216 .

[0128] During the operation of the smart glasses 200 , the photosensor 218 is used to collect light sensing data, the controller 216 is used to adjust the driving parameters of the driving component 214 according to the light sensing data, and the driving component 214 is used to drive the light source component 210 to operate.

[0129] The driving parameters may specifically include the driving current of the driving component 214 and the PWM (Pulse Width Modulation) coefficient, and other parameters that affect the operation of the light source component 210 , which are not specifically limited here.

[0130] In this way, the smart glasses 200 can automatically sense external light data, and then adaptively adjust light source related parameters, and can adapt to different external light intensities, so that the user can always see the viewfinder clearly.

[0131] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0132] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A flexible film, characterized in that include: basal layer; a grating layer, disposed on one side of the base layer; a first protective layer, disposed on a side of the grating layer away from the base layer; The grating layer includes at least one diffraction grating, which includes a plurality of sawtooth grooves. The inclination angle of the grooves satisfies that the diffraction grating diffracts incident parallel light into a bright line, and the extension direction of the bright line is the same as the grating direction of the diffraction grating.

2. The flexible film according to claim 1, characterized in that The grating layer includes a first grating and a second grating; The grating direction of the first grating is a first direction, the grating direction of the second grating is a second direction, the first direction intersects with the second direction, and the first grating intersects with the second grating.

3. The flexible film according to claim 1, characterized in that Also includes: The bonding layer is arranged on the other side of the base layer, and the bonding layer is used to achieve seamless assembly and disassembly of the flexible film and the lens.

4. The flexible film according to claim 1, characterized in that Also includes: The second protective layer is detachably arranged on a side of the first protective layer away from the grating layer, and the hardness of the second protective layer is greater than that of the first protective layer.

5. The flexible film according to claim 1, characterized in that Also includes: a liquid crystal layer disposed between the grating layer and the first protective layer, the liquid crystal layer being configured to sense environmental information of the flexible film and adjust a refraction parameter of the bright line according to the environmental information to adjust a display position of the bright line; The environmental information includes at least one of the following items or a combination thereof: electric field information, temperature information.

6. The flexible film according to claim 2, characterized in that The first direction and the second direction are perpendicular to each other, and the grating period, grating depth and grating width of the different diffraction gratings are consistent.

7. The flexible film according to claim 2, characterized in that At least one first grating and at least one second grating cover a partial area of ​​the grating layer.

8. The flexible film according to any one of claims 1 to 5, characterized in that The diffraction grating is manufactured by a nanoimprint process; or, The diffraction grating is produced by performing double-beam exposure on a photosensitive material. The double-beam exposure is used to adjust the refractive index of the photosensitive material so that the photosensitive material has the optical properties of a grating.

9. A pair of smart glasses, characterized in that: include: Frames; A lens disposed in the frame, wherein at least one flexible film according to any one of claims 1 to 8 is bonded to the lens, wherein the at least one flexible film comprises a plurality of groups of gratings, the plurality of groups of gratings corresponding to the vertex region and the center region of the lens, respectively, each group of gratings comprising a first grating and a second grating arranged to intersect, the grating direction of the first grating being a first direction, and the grating direction of the second grating being a second direction; temples, connected to the frame; A collimated light source module is provided on the temple, and is used to emit parallel light toward the lens. The multiple groups of gratings in at least one of the flexible films are used to diffract the parallel light into multiple groups of bright lines, each group of bright lines includes a first bright line extending along the first direction and a second bright line extending along the second direction, and the first bright line and the second bright line in each group of bright lines intersect.

10. The smart glasses according to claim 9, wherein: Each group of gratings includes a plurality of the first gratings and a plurality of the second gratings, every two of the first gratings are parallel to each other, every two of the second gratings are parallel to each other, and every two of the first gratings and the second gratings intersect each other.

11. The smart glasses according to claim 9, wherein: The collimated light source module comprises: A light source assembly is provided on the temple, and is used for emitting a divergent light source; The lens assembly is arranged on the temple, and is used for converting the divergent light source into parallel light and then irradiating the parallel light to the lens.

12. The smart glasses according to claim 11, wherein: Also includes: a driving assembly, connected to the light source assembly, and configured to drive the light source assembly to operate; a controller connected to the drive assembly; A photosensor is connected to the controller, and the photosensor is used to collect light sensing data. The controller is used to adjust the driving parameters of the driving component according to the light sensing data.

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