Optical film, light-emitting module, motor vehicle, and method for manufacturing optical film

Abstract

The present application provides an optical film (100); the optical film is a single-layer structure, and comprises a first face (10) and a second face (20) arranged opposite one another, and a random optical microstructure (30) is provided on the first face, the optical microstructure being configured to deflect and / or diffuse light. The present application also provides a light-emitting module (300), a motor vehicle, and a method for manufacturing an optical film (100).

Description

Optical film, light-emitting module, motor vehicle, and method for manufacturing optical film

[0001] The present application relates to the technical field of lighting, in particular to an optical film, a light-emitting module, a motor vehicle, and a method for manufacturing an optical film.

[0002] In the technical field of lighting, various lighting or signalling devices are known for providing light for lighting or signalling. For example, vehicle lamps are used in motor vehicles to provide lighting or signalling functions, in order to ensure safe travel or provide an ornamental function.

[0003] Optical films are a common type of optical element, used to deflect or diffuse light in vehicle lamps of motor vehicles. However, most existing optical films are multi-layer film structures, which for example comprise a base layer and an optical glue layer with an optical structure; these two layers can be bonded together to form a multi-layer optical film, to realize a specific optical function. However, multi-layer optical films can fail in various ways; for example, under ultraviolet irradiation or in hot or damp environments, the glue layer with the optical structure can easily fall off, impairing the optical function of the optical film. In addition, the optical glue layer generally needs to be cured, and chemical components therein that have not fully reacted will separate out extremely easily when heated, volatilizing and depositing on an optical lens or reflective bowl, and thereby affecting the light output result. Finally, since the optical glue layer and the base layer have different coefficients of thermal expansion, the multi-layer optical film is liable to curl when heated. All of these limit the widespread application of multi-layer optical films.

[0004] Thus, there is truly an urgent need at present to propose a novel optical film capable of overcoming at least one of the shortcomings mentioned above.Summary of the Invention

[0005] An objective of the present application is to overcome at least one of the problems and shortcomings in the prior art.

[0006] A first aspect of the present application provides an optical film, wherein the optical film is a single-layer structure, and comprises a first face and a second face arranged opposite one another, and a random optical microstructure is provided on the first face, the optical microstructure being configured to deflect and / or diffuse light.

[0007] In some embodiments, a material of the optical film is a single material, and the optical film does not comprise an optical glue layer;

[0008] a thickness of the optical film is less than or equal to 0.2 mm, or the thickness of the optical film is less than or equal to 0.1 mm.

[0009] In some embodiments, the optical microstructure is formed on the first face by a hot-pressing process;

[0010] the second face is a smooth surface.

[0011] In some embodiments, the first face is used as a light entry face to receive light, and the second face is used as a light exit face to output light.

[0012] In some embodiments, a material of the optical film comprises polycarbonate (PC), polyethylene terephthalate (PET) or polymethyl methacrylate (PMMA).

[0013] In some embodiments, a heat resistance temperature of the optical film is greater than or equal to 100°, or the heat resistance temperature of the optical film is greater than or equal to 110°.

[0014] In some embodiments, multiple said optical microstructures are provided, the optical microstructures are non-periodic, completely random structures, and the shapes, sizes and directions of the optical microstructures are not exactly the same.

[0015] In some embodiments, a length and a width of the optical microstructure are 5 - 50 um;

[0016] a depth of the optical microstructure is 1 - 10 um.

[0017] In some embodiments, the optical film is configured to deflect light;

[0018] an angle of deflection of the optical film is greater than or equal to 30°, or the angle of deflection of the optical film is greater than or equal to 45°.

[0019] A second aspect of the present application provides a light-emitting module, comprising an optical film as provided in the first aspect and the above embodiments and a light source;

[0020] the light source is configured to emit light, and the optical film is configured to diffuse and / or deflect the light emitted by the light source.

[0021] A third aspect of the present application provides a motor vehicle, comprising an optical film as provided in the first aspect and the above embodiments, or a light-emitting module as provided in the second aspect.

[0022] A fourth aspect of the present application provides a method for manufacturing an optical film, the method comprising the following steps:

[0023] (S1) holographic exposure: light which has passed through frosted glass is used to irradiate a glass substrate, a surface of which has been coated with photoresist, and a random optical microstructure present on the frosted glass is recorded on the photoresist;

[0024] (S2) transfer: the exposed glass substrate undergoes development and electroplating, and the random optical microstructure is transferred to an electroplated layer of a master plate;

[0025] (S3) hot pressing: the master plate is used to hot-press a single-layer optical film, and the random optical microstructure is formed on a first face of the optical film;

[0026] (S4) demoulding: the optical film is separated from the master plate, and an optical film as provided in the first aspect above and the above embodiments is formed.Brief Description of the Drawings

[0027] is a schematic side view of the structure of an optical film provided in a first embodiment of the present application.

[0028] is a schematic top view of the structure of the optical film shown in.

[0029] is a schematic drawing of the structure of a light-emitting module comprising the optical film shown in.

[0030] is a schematic top view of the structure of an optical film provided in a second embodiment of the present application.

[0031] is a schematic drawing of the structure of a light-emitting module comprising the optical film shown in.

[0032] shows a method for manufacturing an optical film provided in embodiments of the present application.Detailed Description of Embodiments

[0033] Embodiments of the present application will be described in detail below with reference to the drawings. It should be understood that the embodiments of the present application are mainly for illustrating possible implementations of the technical solution of the present application and should not be construed as limiting the technical solution of the present application. In the present description, identical or similar components are indicated by identical or similar reference numerals.

[0034] is a schematic side view of the structure of an optical film 100 provided in a first embodiment of the present application;is a schematic top view of the structure of the optical film 100 shown in; andis a schematic drawing of the structure of a light-emitting module 300 comprising the optical film 100 shown in.

[0035] As shown in Figs. 1 - 3, the first embodiment of the present application provides an optical film 100. The optical film is a single-layer structure, and comprises a first face 10 and a second face 20 arranged opposite one another. A random optical microstructure 30 is provided on the first face 10, the optical microstructure 30 being configured to deflect light, or to diffuse light, or to simultaneously deflect and diffuse light.

[0036] The optical film 100 provided in this embodiment is a single-layer structure rather than a multi-layer structure; compared with a multi-layer optical film, the single-layer optical film 100 has better structural stability, and in particular retains good optical performance under ultraviolet irradiation or in hot or damp environments, so can be widely used in various use scenarios.

[0037] Specifically, the material of the optical film 100 may be a single material, i.e. the optical film 100 only comprises a base layer, and does not comprise the optical glue layer that is generally present in similar multi-layer optical films. Since it has no additional optical glue layer, the single-layer optical film 100 has a smaller thickness. For example, the thickness t of the optical film 100 may be less than or equal to 0.2 mm. Alternatively, preferably, the thickness t of the optical film 100 may be less than or equal to 0.1 mm. The thinner optical film 100 can not only save material, but can also be adapted more effectively to various application scenarios. In addition, since the optical film 100 uses a single material, the problem of inter-layer peeling caused by differences in parameters of multiple materials is avoided. It should be explained that the expression "single material" used herein means that the material is the same in all regions of the entire optical film 100; the obvious layering of materials in similar multi-layer films is not present.

[0038] In some embodiments, a master plate with an optical microstructure may be used to hot-press the first face 10 of the optical film 100, so that the optical microstructure 30 is formed on the first face 10 directly by a hot-pressing process, with no need to provide an additional optical glue layer. For details of the specific method of manufacturing the optical film 100, the detailed description below can be referred to. The second face 20 of the optical film is kept as an original smooth surface.

[0039] Since the first face 10 of the optical film 100 has the optical microstructure 30 and the second face is a smooth surface, the first face 10 can be used as a light entry face of the optical film 100 to receive light, and the second face 20 can be used as a light exit face of the optical film 100 to output light. Compared with using the smooth second face 20 as a light entry face, using the first face 10 with the optical microstructure 30 as a light entry face can reduce reflection of incident light, increasing the overall light output efficiency. However, in other embodiments, it is also possible to use the smooth second face 20 as a light entry face, and the first face 10 with the microstructure as a light output face, in order to adapt to given assembly conditions.

[0040] In some embodiments, the material of the optical film 100 may comprise polycarbonate (PC), polyethylene terephthalate (PET) or polymethyl methacrylate (PMMA). Of course, other similar materials could also be included. The thermal stability of these materials is typically good, so that a heat resistance temperature of the optical film 100 may be greater than or equal to 100°; or preferably, the heat resistance temperature of the optical film 100 may be greater than or equal to 110°. The expression "heat resistance temperature" used herein means that when the temperature of the environment of the optical film 100 reaches the heat resistance temperature, the optical film 100 still has good stability, with no obvious volatilized matter, deformation or peeling. The heat resistance temperature of a conventional optical film is typically 80 - 90°; if the temperature exceeds 90°, there will be obvious volatilized matter, with obvious deformation and / or peeling.

[0041] In this embodiment, as shown in Figs. 1 - 3, there are multiple optical microstructures 30, the multiple microstructures 30 being distributed on the first face of the optical film 100. The optical microstructures 30 are non-periodic, completely random structures, i.e. the shapes, sizes and directions of the optical microstructures 30 are not exactly the same, and there is no pattern or rule to be followed. For example, an optical microstructure 31 is substantially in the form of a strip with a bend, whereas an optical microstructure 32 is substantially round, and the two microstructures have different sizes.

[0042] The size of the optical microstructure 30 in this embodiment is smaller than that of an existing microstructure. For example, a length and a width of the optical microstructure 30 may be 5 - 50 um; and a depth of the optical microstructure 30 is 1 - 10 um. Since the optical microstructures 30 are of smaller size, the optical microstructures 30 can be distributed on the optical film 100 more closely together and uniformly, improving the optical function of the optical film 100. For example, diffusion at a larger angle can be achieved; the diffusion angle may be approximately 100° or even 110°.

[0043] In, light emitted by a light source 200 enters through the first face of the optical film 100 and exits through the second face of the optical film 100; the optical film 100 achieves an isotropic diffusion effect, i.e. a light output pattern P1 formed has the same angle of diffusion in a horizontal direction and a vertical direction.

[0044] is a schematic top view of the structure of an optical film 100 provided in a second embodiment of the present application;is a schematic drawing of the structure of a light-emitting module 300 comprising the optical film 100 shown in.

[0045] As shown in Figs. 4 - 5, the second embodiment of the present application provides an optical film 100. This optical film 100 is similar to the optical film in the first embodiment, the main difference being that the specific structure of the optical microstructure 30 is different. For example, an optical microstructure 31 is in the form of a longer strip, and an optical microstructure 32 is in the form of a shorter strip. The optical microstructure 30 with the structure shown incauses the optical film 100 to realize an anisotropic diffusion effect, i.e. a light pattern P2 formed has different angles of diffusion in a horizontal direction and a vertical direction.

[0046] In other embodiments, the optical film 100 may be configured to deflect light, and not to diffuse light. Using the optical microstructure of the present application, it is possible to realize a large angle of deflection, e.g. the angle of deflection of the optical film 100 is greater than or equal to 30°; or the angle of deflection of the optical film 100 may even be greater than or equal to 45°. The angle of deflection of existing optical films is typically less than 20°. The large angle of deflection capable of being achieved in the present application can further expand the scope of application of the optical film 100. In addition, in some embodiments, the optical film 100 may be configured to simultaneously realize the functions of deflecting light and diffusing light; all that need be done is to design corresponding optical microstructures on the optical film 100.

[0047] As shown in Figs. 3 and 5, embodiments of the present application further provide a light-emitting module 300, which comprises an optical film 100 as described in any one of the embodiments above and a light source 200. The light source 200 is configured to emit light, and the optical film 100 is configured to diffuse and / or deflect the light emitted by the light source 200.

[0048] Embodiments of the present application further provide a motor vehicle, which comprises an optical film 100 as described in any one of the embodiments above, or a light-emitting module 300 as described in any one of the embodiments above.

[0049] shows a method for manufacturing an optical film 100 provided in embodiments of the present application.

[0050] As shown in, embodiments of the present application further provide a method for manufacturing an optical film 100, the method comprising the following steps:

[0051] (S1) Holographic exposure: light (L) which has passed through frosted glass 110 is used to irradiate a glass substrate (120), a surface of which has been coated with photoresist (130), and a random optical microstructure present on the frosted glass is recorded on the photoresist. The light L used for exposure may laser light which has undergone adjustment. The photoresist 130 may be UV glue, which is an adhesive that can cure through irradiation by ultraviolet light.

[0052] (S2) Transfer: the exposed glass substrate 120 undergoes development and electroplating, and the random optical microstructure is transferred to an electroplated layer of a master plate 140. The master plate 140 may be a nickel plate.

[0053] (S3) Hot pressing: the master plate 140 is used to hot-press a single-layer optical film 100, and the random optical microstructure 30 is formed on a first face of the optical film 100.

[0054] (S4) Demoulding: the optical film 100 is separated from the master plate 140, and the optical film 100 as described in any one of the embodiments above is formed.

[0055] It should be explained that different optical microstructures can be produced by adjusting the exposure angle and exposure dose of the light L; these different optical microstructures can realize deflection at various angles and / or diffusion functions.

[0056] Although the present application has been described with reference to the drawings, the embodiments disclosed in the drawings are intended to provide an exemplary illustration of preferred embodiments of the present application, and should not be construed as limiting the present application. The dimensional proportions in the drawings are merely schematic, and must not be construed as limiting the present application.

[0057] Although some embodiments of the general concept of the present application have been shown and explained, those skilled in the art will understand that the present application may comprise other equivalent embodiments without departing from the general inventive concept of the present application, and the scope of protection of the present application is defined by the claims.

Claims

Optical film (100), characterized in that the optical film is a single-layer structure, and comprises a first face (10) and a second face (20) arranged opposite one another, and a random optical microstructure (30) is provided on the first face, the optical microstructure being configured to deflect and / or diffuse light.Optical film according to Claim 1, wherein the optical film is formed by single material, anda thickness (t) of the optical film is less than or equal to 0.2 mm, or the thickness (t) of the optical film is less than or equal to 0.1 mm.Optical film according to Claim 1, wherein the optical microstructure is formed on the first face by a hot-pressing process;the second face is a smooth surface.Optical film according to Claim 1, wherein the first face is used as a light entry face to receive light, and the second face is used as a light exit face to output light.Optical film according to Claim 1, wherein a material of the optical film comprises polycarbonate (PC), polyethylene terephthalate (PET) or polymethyl methacrylate (PMMA).Optical film according to Claim 1, wherein a heat resistance temperature of the optical film is greater than or equal to 100°, or the heat resistance temperature of the optical film is greater than or equal to 110°.Optical film according to Claim 1, wherein multiple said optical microstructures are provided, the optical microstructures are non-periodic, completely random structures, and the shapes, sizes and directions of the optical microstructures are not exactly the same.Optical film according to any one of Claims 1 to 7, wherein a length and a width of the optical microstructure are 5 - 50 um;a depth of the optical microstructure is 1 - 10 um.Optical film according to any one of Claims 1 to 7, wherein the optical film is configured to deflect light;an angle of deflection of the optical film is greater than or equal to 30°, or the angle of deflection of the optical film is greater than or equal to 45°.Light-emitting module (300), characterized in that the light-emitting module comprises the optical film (100) according to any one of Claims 1 - 9 and a light source (200);the light source is configured to emit light, and the optical film is configured to diffuse and / or deflect the light emitted by the light source.Motor vehicle, characterized in that the motor vehicle comprises the optical film (100) according to any one of Claims 1 to 9, or the light-emitting module (300) according to Claim 10.Method for manufacturing an optical film (100), characterized in that the method comprises the following steps:(S1) holographic exposure: light (L) which has passed through frosted glass (110) is used to irradiate a glass substrate (120), a surface of which has been coated with photoresist (130), and a random optical microstructure present on the frosted glass is recorded on the photoresist;(S2) transfer: the exposed glass substrate (120) undergoes development and electroplating, and the random optical microstructure is transferred to an electroplated layer of a master plate (140);(S3) hot pressing: the master plate (140) is used to hot-press a single-layer optical film (100), and the random optical microstructure (30) is formed on a first face of the optical film;(S4) demoulding: the optical film (100) is separated from the master plate (140), and the optical film according to any one of Claims 1 - 9 is formed.

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