Optical film with grating and diffusion structure

Abstract

The invention relates to an optical film with a grating and a diffusion structure. The optical film comprises a grating layer and a waveguide layer arranged below the grating layer. The grating layer can enable specific incident light to be diffracted and coupled into the waveguide layer, and the specific incident light is propagated in the waveguide layer in a total reflection waveguide mode; and the scattering layer is arranged below the waveguide layer in an attached manner, and the totally-reflected light can enter the scattering layer and is emitted from the lower part of the scattering layer after being scattered. Light with the wavelength within a specific range can be diffracted and coupled into a waveguide mode, then the light is emitted from the waveguide through the diffusion film, the light can be seen in the non-light-source perpendicular incidence direction, and a certain filtering effect can be achieved on the emergent light.

Description

Technical Field

[0001] The present disclosure relates to an optical film having a grating and a diffusion structure, belonging to the field of lighting technology. Background Art

[0002] The blue sky lamp is a lamp that emits natural light by imitating the blue sky. It can simulate the effect of opening a window on the ceiling. Currently, the blue sky lamps on the market are divided into two types. One uses the Rayleigh scattering principle and utilizes the principle of particle scattering of blue and violet light to achieve the effect of simulating natural light. The other is to use a blue LED lamp to illuminate the lampshade to form a blue light effect. Both of these two types of blue sky lamps have a common problem, that is, the scattering efficiency of harmful blue light is very strong. Staying under harmful blue light for a long time may affect people's eyesight.

[0003] For example, the Chinese patent document with the publication number CN115926610B discloses a UV coating with Rayleigh scattering function for a blue sky lamp. This UV coating can relatively realistically simulate the effect of the blue sky in a natural state, but has poor blue light filtering ability and cannot play a role in protecting eyesight. Summary of the Invention

[0004] In order to overcome the above problems, the present disclosure provides an optical film having a grating and a diffusion structure.

[0005] The technical solution of the present disclosure is as follows:

[0006] An optical film having a grating and a diffusion structure, the optical film includes a grating layer and a waveguide layer provided below the grating layer;

[0007] The grating layer can diffract specific incident light, couple it into the waveguide layer, and propagate in the waveguide layer in a total reflection waveguide mode;

[0008] A scattering layer, which is adhesively provided below the waveguide layer, can make the totally reflected light enter the scattering layer and exit from below the scattering layer after scattering.

[0009] Further, the grating period T satisfies:

[0010]

[0011] where λ is the wavelength of the incident light, n 0 is the refractive index of the covering layer, and the covering layer is the area above the waveguide layer except for the grating structure, n 1 is the refractive index of the waveguide layer, and θ i is the incident angle of the incident light.

[0012] Further, the grating layer includes a plurality of grating structures with different directions.

[0013] Further, the grating layer includes a plurality of grating units, and each grating unit independently includes a plurality of grating structures with different directions.

[0014] Further, the shape of the grating unit is one or more of a rectangle, a triangle, a sector or a circle; the grating units are in close contact or not in close contact with each other.

[0015] Further, a grating layer and a waveguide layer are sequentially arranged from top to bottom between the waveguide layer and the scattering layer, and there is an overlapping area between the grating structures of the two grating layers.

[0016] Further, the grating units in the overlapping area of the two grating layers are the same or different, and the directions of the grating structures in the overlapping area are the same or different.

[0017] Further, the grating layer includes a plurality of grating structures with different periods.

[0018] Further, the scattering layer covers all or part of the area of the waveguide layer in contact therewith.

[0019] Further, it further includes a light-shielding layer, which is arranged above the waveguide layer and corresponds to the area covered by the scattering layer. The present disclosure has the following beneficial effects:

[0020] Some embodiments of the present disclosure can diffract light with wavelengths in a specific range, couple it into a waveguide mode, and then emit it from the waveguide through a diffusion film, which can be seen in a direction other than directly irradiated by the light source, and can play a certain filtering role on the emitted light.

[0021] Some embodiments of the present disclosure can make the light-emitting area of the lamp present target colors such as blue and green, and the emitted light is white, warm white or other set colors.

[0022] The diffraction light band of some embodiments of the present disclosure is determined by the diffraction period of the grating. By adjusting the grating constant, the band of the diffraction light can be screened, and the scattering efficiency of the harmful band of blue light can be reduced so that it does not enter the human eye, playing a role in protecting eyesight.

[0023] Some embodiments of the present disclosure can control the emission of visible light at different angles, so the sky lamp prepared from this optical film can observe different colors at different angles. The light of different wavelengths is separated at different emission angles, and the color of the lamp is more vivid and pure.

[0024] Some embodiments of the present disclosure use grating structures with different directions to form an optical film by splicing, and there is a visual effect in all directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of an embodiment of the present disclosure.

[0026] Figure 2 Schematic diagram of the grating layer structure according to an embodiment of the present disclosure.

[0027] Figure 3 Schematic diagram of the grating unit structure according to an embodiment of the present disclosure.

[0028] Figure 4 Schematic diagram of the structure according to an embodiment of the present disclosure.

[0029] Figure 5 Schematic diagram of the structure according to an embodiment of the present disclosure.

[0030] Figure 6 Schematic diagram of the structure according to an embodiment of the present disclosure.

[0031] The reference numerals in the figure are represented as:

[0032] 1. Grating layer; 2. Waveguide layer; 3. Scattering layer; 4. Incident light; 5. Diffracted light; 6. Scattered light; 7. Human eye; 8. Exit light; 9. Grating unit; 10. Light-shielding layer. Detailed implementation manners

[0033] In order to make the objectives, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are some but not all of the embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the described embodiments of the present disclosure fall within the scope of protection of the present disclosure.

[0034] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should have the ordinary meanings understood by those of ordinary skill in the art to which the present disclosure belongs. The "first", "second" and similar terms used in the present disclosure do not denote any order, quantity or importance, but are only used to distinguish different components. The terms such as "including" or "comprising" mean that the elements or items appearing before this word cover the elements or items listed after this word and their equivalents, without excluding other elements or items. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left" and "right" are only used to represent relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly. In order to keep the following description of the embodiments of the present disclosure clear and concise, some details of known functions and known components are omitted in the present disclosure.

[0035] The present disclosure will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] As described above Figure 1 An optical film having a grating and a diffusing structure, the optical film comprising a grating layer 1 and a waveguide layer 2 disposed below the grating layer 1;

[0037] The grating layer 1 can diffract specific incident light 4, couple it into the waveguide layer 2, and propagate in the waveguide layer 2 in a total reflection waveguide mode;

[0038] A scattering layer 3 is disposed in contact with the lower surface of the waveguide layer 2, and can allow the totally reflected light to enter the scattering layer 3, and be scattered and emitted from below the scattering layer 3.

[0039] In this embodiment, the incident light 4 is diffracted by the grating layer 1 to obtain diffracted light 5, and the diffracted light 5 is configured to be able to propagate by total reflection in the waveguide layer (it is necessary to satisfy that the refractive index of the region above the waveguide layer is less than that of the waveguide layer, and the diffraction angle is greater than the total reflection angle). Since the energy of the ±1 diffraction orders of grating diffraction is relatively large, it is the main transmission order in the waveguide layer 2. Therefore, the total reflection configuration can only consider the ±1 diffraction orders. In some embodiments, the ±2 diffraction orders and ±3 diffraction orders are also considered.

[0040] When the refractive index of the scattering layer 3 is configured to be greater than the region above the waveguide layer, the waveguide mode of the total reflection light in the waveguide layer 2 is destroyed, and it can enter the scattering layer 3, where it is dispersed and becomes scattered light 6 in all directions, expanding the viewing angle and reaching the human eye. At the same time, the incident light 4 passing through the optical film can also enter the human eye as illumination light 8.

[0041] Let Figure 1 The refractive indices of the overlying layer (usually air) and the waveguide 2 be n 0 and n wg , respectively. The period of the micro-nano diffraction structure on the grating layer 3 is T. When light is incident on the surface grating structure at an incident angle of θ i , the incident light 4 at this time is a directed light, with a wavelength of λ and a diffraction angle of θ j . When the optical diffraction film and the directed light satisfy the following diffraction light coupling equation, the directed light is coupled by the diffraction film into the waveguide layer and propagates along the waveguide direction in the form of total reflection to the adjacent grating detector in the waveguide layer. The diffraction light coupling equation is:

[0042]

[0043] The vector relationship between the micro-nano structure on the diffraction film, the directed light and the light transmitted by its coupling into the waveguide is:

[0044] K in +G = K wg

[0045] In the formula, Kin k is the wave vector pointing to the light, G is the micro-nano diffraction structure vector, and K wg is the wave vector pointing to the light coupled into the waveguide.

[0046] In an embodiment of the present invention, the coupling equation of the ±1-order diffracted light is:

[0047]

[0048] θ j is the diffraction angle;

[0049] The condition for the diffracted light 5 to form a waveguide mode is that the value of the diffraction angle θ j must satisfy being greater than or equal to the total reflection angle θ C from the waveguide layer to the waveguide layer, and less than 90 degrees. From this, the grating period condition required for the +1-order diffracted light to form a guided wave mode can be obtained:

[0050]

[0051] where λ is the wavelength of the incident light, n 0 is the refractive index of the cladding layer, and the cladding layer is the area above the waveguide layer except for the grating structure, and n 1 is the refractive index of the waveguide layer, and θ i is the incident angle of the incident light.

[0052] In an actual scenario, the wavelength and incident angle of the incident light 4 are not easily changed. In this embodiment, by controlling the grating period, the proportion of diffracted light in a specific wavelength band, such as the harmful blue light band, in the diffracted light can be made extremely low, thereby achieving the purpose of filtering harmful blue light.

[0053] This formula is applicable to the diffraction situation of one-dimensional gratings. For two-dimensional gratings, it can be derived from this formula through similar reasoning.

[0054] In an embodiment of the present invention, the grating layer 1 includes a plurality of grating structures with different directions.

[0055] After the incident light reaches the grating layer, the diffracted light generated by grating diffraction is perpendicular to the grating direction and propagates through the transparent waveguide. Part of it propagates to the scattering layer, and part of it propagates to the far end through the transparent waveguide. The multiple-direction gratings ensure that the diffracted blue light can propagate in multiple directions, so that the viewing angle is not limited to a certain direction, but the color can be observed from all angles.

[0056] Reference Figure 2 and 3 In an embodiment of the present invention, the grating layer includes a plurality of grating units 9, and each grating unit independently includes a plurality of grating structures with different directions.

[0057] Each grating unit 9 independently includes a number of grating structures with different directions, such that light emitted from each grating unit can be seen at different positions. The richer the orientations of the grating structures, the better this effect. Figure 2 and 3 the grating structures in

[0058] have 4 directions, namely 9a, 9b, 9c, and 9d. In different embodiments, it can also be set to 6, 8, 10, or more directions.

[0059] This embodiment enables the optical film to present different patterns.

[0060] Reference Figure 4 , in an embodiment of the present invention, a grating layer 1 and a waveguide layer 2 are sequentially arranged from top to bottom between the waveguide layer 2 and the scattering layer 3, and there is an overlapping area between the grating structures of the two grating layers 1.

[0061] Multiple layers of gratings can increase the diffraction effect, making the colors more vivid.

[0062] In an embodiment of the present invention, the grating units in the overlapping area of the two grating layers are the same or different, and the directions of the grating structures in the overlapping area are the same or different.

[0063] Grating structures with different directions can make the viewing effect of the optical film more uniform in all directions.

[0064] Reference Figure 5 , in an embodiment of the present invention, the grating layer includes a number of grating structures with different periods. The grating structures are as shown by 1a, 1b, and 1c in Figure 5 .

[0065] In this embodiment, when the incident light angle is fixed, the grating layer 1 is composed of 3 different periods. Therefore, the diffraction light wavelengths generated by these three periods are different, and the colors of the scattered light 6 are different. The incident light 4 becomes the outgoing light 8 after passing through the optical film and can be used as illumination light.

[0066] In an embodiment of the present invention, the scattering layer 3 covers all or part of the area of the waveguide layer 2 that is in contact with it.

[0067] Since the diffraction light 5 propagates in the waveguide layer 2 in the form of total reflection, in the area where the scattering layer 3 is not provided, the diffraction light 5 cannot exit until it propagates to the end of the waveguide layer 2 or the area covered by the scattering layer 3 to form the outgoing light 8. This embodiment can control the pattern of the optical film.

[0068] It further includes a light-shielding layer 10, which is disposed above or below the grating layer 1, the waveguide layer 2, or the scattering layer 3, and the light-shielding layer 10 completely covers or partially covers the grating layer 1, the waveguide layer 2, or the scattering layer 3.

[0069] Reference Figure 6 , in an embodiment of the present invention, it further includes a light-shielding layer 10, which is disposed above the waveguide layer 2 and corresponds to the covering area of the scattering layer 3.

[0070] There is no outgoing light 8 at the position of the reflective layer 10, only scattered light 6. Because there is no interference from the outgoing light 8, the color purity is higher.

[0071] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram may represent a module, a program segment, or a part of code, which contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and the combinations of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0072] The units described in the embodiments of the present disclosure can be implemented in software or in hardware. Among them, the name of the unit does not constitute a limitation to the unit itself in some cases.

[0073] The functions described above in this article can be at least partially executed by one or more hardware logic components. For example, without limitation, the exemplary types of hardware logic components that can be used include: Field Programmable Gate Array (FPGA), Application Specific Integrated Circuit (ASIC), Application Specific Standard Product (ASSP), System on Chip (SOC), Complex Programmable Logic Device (CPLD), and so on.

[0074] The above description is only a preferred embodiment of the present disclosure and an explanation of the applied technical principles. Those skilled in the art should understand that the scope of disclosure involved in the present disclosure is not limited to the technical solutions formed by the specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosure concept. For example, the technical solutions formed by mutually replacing the above features with the technical features (but not limited to) having similar functions disclosed in the present disclosure.

[0075] In addition, although the operations are depicted in a particular order, this should not be construed as requiring that the operations be performed in the particular order shown or in sequential order. In certain environments, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of the present disclosure. Certain features described in the context of separate embodiments may also be implemented combinatorially in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented separately or in any suitable sub-combination in multiple embodiments.

[0076] Although the subject matter has been described in language specific to structural features and / or methodological logical acts, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. On the contrary, the specific features and acts described above are merely example forms for implementing the claims.

[0077] Regarding the present disclosure, the following points need to be noted:

[0078] (1) The drawings of the embodiments of the present disclosure only relate to the structures involved in the embodiments of the present disclosure, and other structures can refer to the general design.

[0079] (2) Without conflict, the embodiments of the present disclosure and the features in the embodiments can be combined with each other to obtain new embodiments.

[0080] The above is only the embodiment of the present disclosure, and thus does not limit the patent scope of the present disclosure. Any equivalent structure made by using the content of the specification and drawings of the present disclosure, directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present disclosure by the same token.

Claims

1. An optical film having a grating and a diffusion structure, characterized in that: The optical film includes a grating layer and a waveguide layer disposed below the grating layer; The grating layer can diffract specific incident light, couple it into the waveguide layer, and propagate in the waveguide layer in a total reflection waveguide mode; The scattering layer is arranged below the waveguide layer, and can make the totally reflected light enter the scattering layer and be emitted from below the scattering layer after scattering.

2. The optical film with grating and diffusion structure according to claim 1, characterized in that: The grating period T satisfies: Wherein, λ is the wavelength of incident light, n0 is the refractive index of the cover layer, the cover layer is the area above the waveguide layer except the grating structure, n1 is the refractive index of the waveguide layer, θ i is the incident angle of the incident light.

3. The optical film with grating and diffusion structure according to claim 1, characterized in that: The grating layer includes a plurality of grating structures with different directions.

4. The optical film with grating and diffusion structure according to claim 1, characterized in that: The grating layer includes a plurality of grating units, and each grating unit independently includes a plurality of grating structures with different directions.

5. The optical film having a grating and a diffusion structure according to claim 4, characterized in that: The shape of the grating unit is one or more of a rectangle, a triangle, a sector or a circle; the grating units are closely connected or not closely connected.

6. The optical film with grating and diffusion structure according to claim 4, characterized in that: A grating layer and a waveguide layer are sequentially arranged between the waveguide layer and the scattering layer from top to bottom, and there is an overlapping area in the grating structures of the two grating layers.

7. The optical film with grating and diffusion structure according to claim 6, characterized in that: The grating units in the overlapping area of ​​the two grating layers are the same or different, and the grating structure directions in the overlapping area are the same or different.

8. The optical film with grating and diffusion structure according to any one of claims 1 to 6, characterized in that: The grating layer includes a plurality of grating structures with different periods.

9. The optical film with grating and diffusion structure according to any one of claims 1 to 6, characterized in that: The scattering layer covers the entire area or a part of the area of ​​the waveguide layer attached thereto.

10. The optical film with grating and diffusion structure according to any one of claims 1 to 6, characterized in that: It also includes a light shielding layer, which is arranged above the waveguide layer and corresponds to the coverage area of ​​the scattering layer.

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