Light-transmitting member, light source device, method for producing light-transmitting member, and method for producing light source device

Abstract

To provide a light-transmitting member, a light source device, a method for producing a light-transmitting member, and a method for producing a light source device, which are capable of suppressing scratch generation.SOLUTION: A light-transmitting member comprises: a light-transmitting substrate having a first surface and a second surface on the opposite side of the first surface; a light-transmitting first film that covers the first surface; a light-transmitting second film that covers the second surface; and a light-transmitting third film disposed on the second film. The first film contains hydrated alumina; the second film contains aluminum oxide having a crystallinity lower than that of α-alumina; and the third film has greater hardness than that of the second film.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a light-transmissive member, a light source device, a method for manufacturing a light-transmissive member, and a method for manufacturing a light source device. [Background technology]

[0002] Conventionally, there is known a technique for forming a grass-like alumina film over the entire surface of an object such as glass or a lens. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2020-537188 Summary of the Invention [Problem to be solved by the invention]

[0004] When an object has a conventional turf-like alumina film formed thereon, there is a risk that the turf-like alumina film may be damaged during transportation or the like.

[0005] An object of the present disclosure is to provide a highly reliable light-transmissive member, a light source device, a method for manufacturing a light-transmissive member, and a method for manufacturing a light source device. [Means for solving the problem]

[0006] According to one embodiment of the present disclosure, a light-transmitting member includes a light-transmitting base material having a first surface and a second surface opposite to the first surface, a light-transmitting first film covering the first surface, a light-transmitting second film covering the second surface, and a light-transmitting third film provided on the second film, wherein the first film contains hydrated alumina, the second film contains aluminum oxide having a lower crystallinity than alpha-alumina, and the hardness of the third film is greater than the hardness of the second film.

[0007] According to another aspect of the present disclosure, a method for manufacturing a light-transmitting member comprising a first film, a second film, and a third film includes the steps of: preparing a light-transmitting base material comprising a first surface and a second surface opposite to the first surface; forming a light-transmitting aluminum oxide film covering the first surface and the second surface and containing aluminum oxide having a lower crystallinity than alpha-alumina; forming a light-transmitting third film on the aluminum oxide film on the second surface to obtain an intermediate structure; and hydrating the intermediate structure to convert the aluminum oxide film into a first film containing hydrated alumina and disposed on the first surface, and a second film containing aluminum oxide and having a lower crystallinity than alpha-alumina and disposed on the second surface. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a highly reliable light-transmissive member, a light source device, a method for manufacturing a light-transmissive member, and a method for manufacturing a light source device. [Brief description of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing a light-transmitting member according to a first embodiment. [Diagram 2] 3A to 3C are cross-sectional views illustrating a method for manufacturing a light-transmitting member according to the first embodiment. [Diagram 3] 3A to 3C are cross-sectional views illustrating a method for manufacturing a light-transmitting member according to the first embodiment. [Figure 4] FIG. 11 is a top view showing a light source device according to a second embodiment. [Diagram 5] FIG. 6 is a cross-sectional view showing a light source device according to a second embodiment. [Figure 6] 13 is a diagram showing an example of the arrangement of light-emitting sections in a light source device according to a second embodiment. FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] 10 is a flowchart showing a method for manufacturing the light source device according to the second embodiment. [Figure 9]6A to 6C are cross-sectional views showing a method for manufacturing the light source device according to the second embodiment. [Figure 10] 6A to 6C are cross-sectional views showing a method for manufacturing the light source device according to the second embodiment. [Figure 11] 6A to 6C are cross-sectional views showing a method for manufacturing the light source device according to the second embodiment. [Figure 12] FIG. 11 is a cross-sectional view showing a light source device according to a third embodiment. [Figure 13] FIG. 13 is a bottom view showing a lens and a support portion in the third embodiment. [Figure 14] FIG. 11 is a cross-sectional view showing a light source device according to a fourth embodiment. [Figure 15] FIG. 13 is a bottom view showing a lens and a support portion in the fourth embodiment. [Figure 16] FIG. 13 is a cross-sectional view showing a light source device according to a fifth embodiment. [Figure 17] FIG. 13 is a bottom view showing a lens and a support portion in the fifth embodiment. [Figure 18] 13 is a flowchart showing a method for producing a third sample. [Figure 19] 13 is a flowchart showing a method for producing a fourth sample. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment for carrying out the present disclosure will be described with reference to the drawings. The following description is for embodying the technical idea of ​​the present disclosure, and unless otherwise specified, the present disclosure is not limited to the following description.

[0011] In each drawing, components having the same function may be given the same symbol. In consideration of the explanation or ease of understanding of the main points, the embodiments may be shown separately for convenience, but partial replacement or combination of the configurations shown in different embodiments or examples is possible. In the embodiments shown later, differences from the embodiments shown earlier are mainly explained, and overlapping explanations of matters common to the embodiments shown earlier may be omitted. The size and positional relationship of the components shown in each drawing may be exaggerated to clarify the explanation. An end view showing only the cut surface may be used as a cross-sectional view.

[0012] Of the first and second surfaces of the light-transmitting member according to the embodiment, the first surface corresponds to the "lower surface" and the second surface corresponds to the "upper surface", with the direction in which the first surface faces being the "lower side" and the direction in which the second surface faces being the "upper side". The same vertical positional relationship applies to other components according to the embodiment. However, this does not limit the orientation of the light-transmitting member and light source device according to the embodiment when in use.

[0013] In addition, in this specification or claims, when there are multiple elements of a certain type and each element is to be expressed with a distinction, the elements may be distinguished by adding "first," "second," etc. to the beginning of the element. In addition, the objects to be distinguished may differ between this specification and the claims. Therefore, even if the claims describe an element with the same notation as this specification, the object identified by this element may not match between this specification and the claims.

[0014] For example, when there are elements distinguished by the notation "first", "second", and "third" in this specification, and the elements to which "first" and "third" are attached in this specification are described in the claims, or when the elements to which "first" is attached and the elements to which no specific ordinal number is attached are described in the claims, the elements may be distinguished by the notation "first" and "second" in the claims from the viewpoint of readability. In this case, the elements to which "first" and "second" are attached in the claims refer to the elements to which "first" and "third" are attached in this specification, or the elements to which no specific ordinal number is attached, respectively. Note that this rule is not limited to the application of elements, and can be applied rationally and flexibly to other objects as well.

[0015] First Embodiment A first embodiment will be described. The first embodiment relates to a light-transmitting member.

[0016] [Structure of the light-transmitting member according to the first embodiment] First, a description will be given of the structure of the light-transmitting member according to the first embodiment. Fig. 1 is a cross-sectional view showing the light-transmitting member according to the first embodiment.

[0017] The light-transmitting member 100 according to the first embodiment includes a light-transmitting base material 110, a light-transmitting first film 111, a light-transmitting second film 112, and a light-transmitting third film 113. The light-transmitting property here refers to a property that allows 60% or more of incident light to pass through. The base material 110 includes a first surface 110A and a second surface 110B located on the opposite side of the first surface 110A. The first film 111 covers the first surface 110A. The second film 112 covers the second surface 110B. The third film 113 is provided on the second film 112.

[0018] In this embodiment, the first film 111 covers the entire first surface 110A, and the second film 112 covers the entire second surface 110B. The first film 111 is in contact with the first surface 110A, the second film 112 is in contact with the second surface 110B, the third film 113 is in contact with the second film 112, and covers the entire second surface 110B from above the second film 112. Note that the first film 111 only needs to cover at least a part of the first surface 110A, and the second film 112 only needs to cover at least a part of the second surface 110B.

[0019] The substrate 110 has light transmittance and is made of, for example, a transparent resin such as polycarbonate resin, acrylic resin, silicone resin, epoxy resin, or glass. The first film 111 contains hydrated alumina (hydrated aluminum oxide). The composition of the hydrated alumina is represented by Al2O3·nH2O (0 < n ≤ 3). The first film 111 may be a hydrated alumina film. In this embodiment, the first film 111 has a turf-like appearance with fine irregularities. The second film 112 contains aluminum oxide with a crystallinity lower than that of α-alumina. The second film 112 may be an aluminum oxide film with a crystallinity lower than that of α-alumina. The hardness of the third film 113 is higher than the hardness of the second film 112. The "hardness" in the present disclosure is "Vickers hardness". The third film 113 contains, for example, silicon oxide. The third film 113 may be a silicon oxide film.

[0020] The hydrated alumina of this embodiment contains fine irregularities. By disposing the hydrated alumina of this embodiment between two media having different refractive indices, a stepwise change (including a linear or curved change) can be provided between the respective refractive indices of the two media, and the transmittance of light transmitted through the two media can be improved. In this embodiment, the two media are the substrate 110 and air, respectively. Therefore, the first film 111 containing hydrated alumina can reduce the reflection of light on the first surface 110A.

[0021] The hydrated alumina contained in the first film 111 has fine irregularities, and the height of the convex portions is equal to or less than the wavelength of the transmitted light. The hydrated alumina contained in the first film 111 has fine irregularities, and the distance between adjacent convex portions is equal to or less than the wavelength of the transmitted light. The thickness of the first film 111 is preferably 200 nm or more and 300 nm or less. This makes it easier to transmit visible light as described below. The thickness of the second film 112 is not limited, but is preferably 25 nm or more and 45 nm or less. This makes it possible to improve the transmittance of visible light. The thickness of the third film 113 is preferably 80 nm or more and 135 nm or less. This makes it possible to improve the transmittance of visible light.

[0022] Also, a light-transmitting film containing silicon oxide or the like may be present between the first film 111 and the base material 110. Furthermore, a light-transmitting film containing silicon oxide or the like may be disposed on the first film 111. The light-transmitting film containing silicon oxide or the like protects the first film 111, thereby making it possible to reduce a decrease in light transmittance due to a change in the surface state or properties of the first film 111, for example, in a high-temperature and high-humidity environment.

[0023] [Method of manufacturing the light-transmitting member according to the first embodiment] Next, a method for manufacturing the light-transmitting member 100 according to the first embodiment will be described. Figures 2 to 4 are cross-sectional views showing the method for manufacturing the light-transmitting member 100 according to the first embodiment.

[0024] The manufacturing method of the light-transmitting member 100 according to the first embodiment is a manufacturing method of a light-transmitting member including a first film 111, a second film 112, and a third film 113, and includes a step of preparing a light-transmitting base material 110, a step of forming a light-transmitting aluminum oxide film 112X, a step of obtaining an intermediate structure 114, and a step of hydrating the intermediate structure 114.

[0025] First, a step of preparing a light-transmitting base material 110 is performed. In the step of preparing a light-transmitting base material 110, as shown in FIG. 2, a light-transmitting base material 110 having a first surface 110A and a second surface 110B is prepared. In this embodiment, the first surface 110A and the second surface 110B are each flat. At least one of the first surface 110A and the second surface 110B may be a rough surface, and may include at least one of a concave surface and a convex surface. When at least one of the first surface 110A and the second surface 110B is a rough surface, and the larger the surface roughness, the more the light transmittance of the first film 111 can be improved.

[0026] Next, a step of forming a light-transmitting aluminum oxide film 112X is performed. In the step of forming the light-transmitting aluminum oxide film 112X, the light-transmitting aluminum oxide film 112X containing aluminum oxide having a lower crystallinity than α-alumina is formed so as to cover the first surface 110A and the second surface 110B of the base material 110. The aluminum oxide film 112X can be formed by, for example, an atomic layer deposition (ALD) method. The film formation temperature is, for example, 80° C. or higher and 100° C. or lower. The aluminum oxide film 112X formed by the ALD method at about 100° C. contains aluminum oxide having a lower crystallinity than α-alumina. The aluminum oxide film 112X may contain amorphous aluminum oxide. An example of an aluminum oxide having a lower crystallinity than α-alumina is γ-alumina.

[0027] Next, a process for obtaining the intermediate structure 114 is performed. In the process for obtaining the intermediate structure 114, as shown in FIG. 3, a light-transmitting third film 113 is formed on the aluminum oxide film 112X of the second surface 110B. The third film 113 can be formed by, for example, a sputtering method or a vapor deposition method. According to the sputtering method, the film can be formed at a temperature equal to or higher than room temperature, and according to the vapor deposition method, the film can be formed at a temperature equal to or higher than about 80° C. Therefore, the film formation temperature of the third film 113 is equal to or higher than room temperature (about 30° C.) and equal to or lower than 100° C. In the formation of the third film, for example, when the ALD method is used, a flat and dense film can be formed at the atomic layer level, but since the third film is formed on both the first surface and the second surface, it is necessary to place a mask or the like on the first surface, which complicates the film formation process. In this embodiment, the third film 113 is formed in a desired region (i.e., only on the second surface 110B) by using the sputtering method or the vapor deposition method. The intermediate structure 114 obtained thereby includes a substrate 110, an aluminum oxide film 112X provided on a first surface 110A of the substrate 110, an aluminum oxide film 112X provided on a second surface 110B of the substrate 110, and a third film 113 provided on the aluminum oxide film 112X on the second surface 110B.

[0028] Next, a step of hydrating the intermediate structure 114 is performed. In this step, the intermediate structure 114 is hydrated. In the step of hydrating the intermediate structure 114, it is preferable to make the hardness of the third film 113 higher than that of the second film 112. In the hydration step, for example, the intermediate structure 114 is exposed to a liquid having a temperature of 70° C. or higher and 100° C. or lower, or water containing water vapor. By the hydration step, hydrated alumina is produced from the aluminum oxide contained in the aluminum oxide film 112X provided on the first surface 110A. The aluminum oxide may contain aluminum oxide hydroxide (AlO(OH)). In the hydration step, for example, the following chemical changes occur. Al2O3+H2O→2AlO(OH) ···(1) 2AlO(OH)→Al2O3·H2O ···(2) 2AlO(OH)+2H2O→Al2O3·3H2O ···(3) Al2O3 + nH2O → Al2O3·nH2O (n = 1.4 - 3) ···(4)

[0029] (1) and (2) chemical changes are likely to occur when the temperature of water or steam is 80°C or higher. In the chemical reaction of (2), boehmite (monohydrate aluminum oxide) is produced. 2AlO(OH) produced in (1) may also exist. The chemical change of (3) is likely to occur when the temperature of water or steam is less than 80°C. In the chemical reaction of (3), bayerite (trihydrate aluminum oxide) is produced. In the chemical reaction of (4), pseudo-boehmite (n-hydrate aluminum oxide) is produced. Therefore, at least a part of the aluminum oxide contained in the aluminum oxide film 112X changes to hydrated alumina through the process of hydration treatment. The hydrated alumina (2), (3), and (4) produced by the hydration treatment is considered to contain Al2O3·nH2O (1 ≤ n ≤ 3). Note that the hydrated alumina (1), (2), (3), and (4) produced by the hydration treatment is considered to contain Al2O3·nH2O (0 < n ≤ 3).

[0030] On the other hand, since the aluminum oxide film 112X provided on the second surface 110B is covered by the third film 113 with a thickness of 80 nm or more and 135 nm or less, it is less likely to be affected by the hydration treatment. By performing the hydration treatment on the intermediate structure 114, the aluminum oxide film 112X is made into a first film 111 containing hydrated alumina disposed on the first surface 110A and a second film 112 containing aluminum oxide with a lower crystallinity than α-aluminum oxide disposed on the second surface 110B.

[0031] In this way, the light-transmissive member 100 shown in FIG. 1 can be manufactured.

[0032] In the light-transmitting member 100 of this embodiment, different films are arranged on the first surface 110A and the second surface 110B of the base material 110. Since the first film 111 containing hydrated alumina is fragile, when a tool such as a suction nozzle contacts the first film 111 to transport the light-transmitting member 100, the first film 111 may be scratched. In the embodiment of the present disclosure, the third film 113, which has a higher hardness than the first film 111 containing hydrated alumina, is arranged on the second surface 110B side, and the light-transmitting member 100 is transported with a tool such as a suction nozzle contacting the third film 113, thereby reducing damage to the first film 111. Furthermore, since the hardness of the third film 113 is higher than that of the second film 112, the occurrence of scratches on the second film 112 can also be reduced. In this embodiment, the thermal expansion coefficients of the substrate 110, the second film 112, and the third film 113 are smaller in this order. For example, the substrate 110 contains polycarbonate resin, the second film 112 contains aluminum oxide, and the third film 113 contains silicon oxide. In this way, by decreasing the thermal expansion coefficients of the films formed on the second surface 110B of the substrate 110 with increasing distance from the substrate 110, it is possible to reduce peeling of the films from the substrate 110. Furthermore, by arranging the second film 112 and the third film 113 on the second surface 110B of the substrate 110 in this order in contact with each other so that the refractive index of the films decreases stepwise, it is possible to obtain a film close to an optical design that reduces light reflection.

[0033] <Second embodiment> Next, a second embodiment will be described. The second embodiment relates to a light source device.

[0034] [Structure of the light source device according to the second embodiment] First, the structure of the light source device according to the second embodiment will be described. FIG. 4 is a top view showing the light source device according to the second embodiment. FIG. 5 is a cross-sectional view showing the light source device according to the second embodiment. FIG. 6 is a diagram showing an example of the arrangement of the light emitting section in the light source device according to the second embodiment. The first light-transmissive member in the light source device according to the second embodiment is mainly different from the first embodiment in that the base material includes a first lens. As an example, the light source device 200 is mounted on a smartphone and is a light source device for a flash in an imaging device provided in the smartphone. The imaging device includes a camera that captures still images and a video camera that captures moving images.

[0035] As shown in FIGS. 4 to 6, the light source device 200 according to the second embodiment includes a light source 10 including a light emitting unit 1, and a first light-transmissive member 201. The first light-transmissive member 201 includes a base material 210 including a first lens 11 and a first support portion 25. The first support portion 25 is provided around the first lens 11 and supports the first lens 11. The first lens 11 includes a first surface 210A and a second surface 210B located on the opposite side of the first surface 210A. In this embodiment, the first surface 210A and the second surface 210B of the first lens 11 each include a convex surface. The first lens 11 may include a biconvex lens. In this embodiment, the light emitting unit 1 includes a plurality of light emitting units 1a to 1i, and the first surface 210A is disposed opposite the light emitting units 1a to 1i. In the following description, the light emitting units 1a to 1i may be collectively referred to as the light emitting unit 1. First lens 11 has, on a first surface 210A of first lens 11, incident portion 12A into which light from light-emitting portion 1 is incident, and has, on a second surface 210B of first lens 11, exit portion 12B from which light transmitted through first lens 11 exits. First lens 11 may further have a light guide portion 21 disposed so as to surround the entire circumference of incident portion 12. Light guide portion 21 guides the light incident from incident portion 12.

[0036] The light source device 200 may further include a substrate 41, a second light-transmissive member 202, and a third support portion 51. The second light-transmissive member 202 includes a second lens 31 and a second support portion 38. The light-emitting portion 1 is mounted on the substrate 41. The third support portion 51 is provided around the first light-transmissive member 201 and the second light-transmissive member 202. The second light-transmissive member 202 is supported by the third support portion 51 on the first light-transmissive member 201 so as to overlap the first light-transmissive member 201 in a top view. For example, the first support portion 25 is fixed to the substrate 41 by an adhesive member 61A. The third support portion 51 is fixed to the first light-transmissive member 201 by an adhesive member 61B, and is fixed to the substrate 41 by an adhesive member 61C. The third support portion 51 has a circular opening 52 that overlaps with the first lens 11 of the first translucent member 201 when viewed from above, and the second translucent member 202 is fixed to the third support portion 51 by being disposed within the opening 52.

[0037] As shown in FIG. 6, the light-emitting units 1a to 1i are arranged in a square lattice pattern with three rows and three columns. In this embodiment, the light-emitting units 1a to 1i are aligned at equal intervals vertically and horizontally, but the arrangement of the light-emitting units 1 is not limited to this. The number of light-emitting units is not limited to nine, and may be one or more. When there are multiple light-emitting units 1, they may be arranged in a square lattice pattern or rectangular lattice pattern with one row and two or more columns. When there are multiple light-emitting units 1, the light-emitting units 1 can be turned on and off individually or in groups.

[0038] In the light source device 200, the first lens 11 has an optical axis C1. In this embodiment, the optical axis C1 of the first lens 11 is located at a position overlapping the light emitting unit 1e located at the center of the light emitting units 1a to 1i in a top view. That is, the light source device 200 has the light emitting unit 1 and a first light-transmissive member 201 arranged in the path of the light emitted by the light emitting unit 1. In addition, in the light source device 200, the second lens 31 has an optical axis C2. In this embodiment, the optical axis C2 of the second lens 31 is located at a position overlapping the light emitting unit 1e located at the center of the light emitting units 1a to 1i in a top view. It is preferable that the optical axis C1 of the first lens 11 and the optical axis C2 of the second lens 31 are approximately the same. In the example shown in FIG. 5, the optical axis C1 of the first lens 11, the optical axis C2 of the second lens 31, and the center R of the light emitting unit 1e are overlapped in a top view.

[0039] (First translucent member 201) Next, a specific configuration of the first light-transmissive member 201 will be described.

[0040] In this embodiment, the first light-transmissive member 201 includes a light-transmissive base material 210 including a first lens 11 and a first support portion 25. The base material 210 is formed of a light-transmissive resin such as polycarbonate resin, acrylic resin, silicone resin, or epoxy resin. The first lens 11 is disposed on the light-emitting unit 1 such that a first surface 210A of the first lens 11 faces the light-emitting surface 7. The first lens 11 collects light from the light-emitting unit 1 and emits the collected light to the second lens 31 side. An example of the first lens 11 is a collimator lens. The shape of the first lens 11 is preferably a circle or an ellipse when viewed from above, and may be a polygon such as a rectangle or a hexagon. In this embodiment, a first light-transmissive member 201 is configured having a first lens 11, a light-transmissive first film 211 covering a first surface 210A of the first lens 11, a light-transmissive second film 212 covering a second surface 210B of the first lens 11, and a light-transmissive third film 213 provided on the second film 212. In the example shown in FIG. 5, the light-transmissive first film 211 further covers a first surface 210a of the first support portion 25. The light-transmissive second film 212 and the light-transmissive third film 213 further cover a second surface 210b of the first support portion 25. The light-transmissive property here refers to a property that can transmit 60% or more of incident light.

[0041] The first lens 11 includes, on a first surface 210A facing the light-emitting unit 1, an entrance portion 12A arranged in the center and into which light from the light-emitting units 1a to 1i is incident, and a light-guiding portion 21 arranged in an annular shape on the outside of the entrance portion 12A and guiding the light incident from the entrance portion 12A. In this embodiment, the annular shape includes not only a round shape such as a ring, but also a shape that is closed and does not intersect with itself. The shape of the lower surface of the first lens 11 may be a rotationally symmetric shape. When the light source device 200 is used as a flash light source for a smartphone or the like, the shape of the lower surface of the first lens 11 may be a four-fold rotationally symmetric shape or a two-fold rotationally symmetric shape when viewed from above, taking into consideration that the shooting range of a general camera is rectangular.

[0042] The incident portion 12A is a recess formed on the lower surface of the first lens 11 and formed with a size such that the light emitting portion 1 is located inside when viewed from above. In this embodiment, the shape of the bottom surface of the recess is circular when viewed from above, but it may be elliptical, triangular, rectangular, hexagonal, or the like. In addition, it is preferable that the bottom surface of the recess has a Fresnel lens shape. That is, it is preferable that the incident portion 12A has a lower convex surface 14 arranged in the center and convex toward the light emitting portion 1, and a convex portion 16 arranged in a ring shape around the lower convex surface 14 and protruding toward the light emitting portion 1. Furthermore, it is preferable that the convex portion 16 is arranged in a ring shape continuously or intermittently around the lower convex surface 14. Here, the convex portion 16 is formed in a ring shape, but it may be formed to have multiple rings. By providing the convex portion 16, the radius of the lower convex surface 14 can be reduced, so that more light from the light emitting portion 1 can be taken in, and the light collection ability is improved. In addition, the inner surface 22 of the recess is preferably a flat surface, but may be a curved surface.

[0043] The light guide 21 is disposed on the lower surface side of the first lens 11, outside the incident portion 12A in a top view. The light guide 21 has an inclined surface 23 that reflects the light incident from the incident portion 12A. The light guide 21 is preferably formed continuously or intermittently in a ring shape around the incident portion 12A. This makes it possible to collect light that has a large emission angle and is emitted toward the outside of the desired irradiation range, among the light emitted from the light emitter 1, by the light guide 21, and improves the light extraction efficiency. The inclination angle of the inclined surface 23 with respect to the optical axis C1 of the first lens 11 is appropriately set to an angle at which the light from the light emitter 1 can be incident and reflected. The inclination angle of the inclined surface 23 with respect to the optical axis C1 of the first lens 11 is preferably an angle at which the light from the light emitter 1 is totally reflected. The first surface 210A of the first lens 11 may have a totally reflecting surface.

[0044] The upper surface of the first light-transmitting member 201 has, for example, the second surface 210B of the first lens 11 and a flat portion 19 surrounding the entire circumference of the second surface 210B of the first lens 11. The second surface 210B of the first lens 11 has an upper convex surface 17 and an upper concave surface 18. The upper convex surface 17 is disposed at the center of the second surface 210B and has a convex shape toward the second lens 31 side. The upper concave surface 18 is disposed in an annular shape so as to surround the entire circumference of the upper convex surface 17 and is continuous with the upper convex surface 17. The flat portion 19 is disposed so as to surround the entire circumference of the upper concave surface 18 and is continuous with the upper concave surface 18. For example, the upper concave surface 18 is provided outside the lower convex surface 14 when viewed from above. The first lens 11 has an upper convex surface 17, so that the light incident from the lower convex surface 14 or the convex portion 16 of the incident portion 12A, or both of these, can be easily extracted to the second lens side. In addition, the first lens 11 has an upper concave surface 18, so that the light reflected by the inclined surface 23 can be easily extracted to the second lens side. Furthermore, the first lens 11 has an upper concave surface 18, so that the inclination angle of the inclined surface 23 with respect to the optical axis C1 of the first lens 11 can be made smaller. This allows the lens diameter of the first lens 11 to be made smaller, and therefore the lens diameter of the second lens 31 can also be made smaller. Furthermore, this allows the diameter of the opening 52 of the third support portion 51 described later to be made smaller. This makes it difficult to see the inside of the opening 52, and improves the appearance. The lower surface of the substrate 210 is an example of the first surface, and the upper surface of the substrate 210 is an example of the second surface.

[0045] The first support portion 25 extends laterally from the outer edge of the first lens 11. The first support portion 25 has a first upper portion 25a and a first leg portion 25b. The first upper portion 25a extends laterally from the outer edge of the first lens 11. The first leg portion 25b extends from the first upper portion 25a to the substrate 41 side. The first support portion 25 extends laterally from the outer edge of the first lens 11 and is formed in an annular shape so as to surround the first lens 11. The first upper portion 25a has a flat upper portion and is formed to be approximately the same height as the upper end of the upper convex surface 17 of the first lens 11. For example, the first leg portion 25b is formed in a cylindrical shape continuing to the side of the first upper portion 25a. For example, the first lens 11 and the first support portion 25 are integrally formed from the same member. The first lens 11 and the first support portion 25 may be formed from different materials. For example, the first lens 11 may be made of a light-transmitting resin or glass material, and the first support portion 25 may be made of a metal such as an aluminum alloy.

[0046] The lower surface of the first leg portion 25b of the first support portion 25 and the upper surface of the substrate 41 are adhered to each other by an adhesive member 61A. That is, the base material 210 is fixed to the substrate 41. As the adhesive member 61A, an adhesive material such as a resin or an adhesive tape can be used.

[0047] The first film 211 covers the incident portion 12A and the inclined surface 23 of the first lens 11. In this embodiment, the first film 211 covers the lower convex surface 14, the convex portion 16, the inner side surface 22 of the recess, and the inclined surface 23 of the first lens 11. That is, the first film 211 covers the first surface 210A, which is the incident surface of the substrate 210. It is preferable that the first film 211, the optical axis C1 of the first lens 11, and the light emitting surface of the light emitting unit 1 overlap in a top view. In this embodiment, the optical axis C1 of the first lens 11 is located at a position overlapping with the light emitting unit 1e in a top view, and the optical axis C1 of the first lens 11 overlaps with the light emitting surface 7e. For example, when the light emitted by the light emitting unit 1e of the light source device 200 is used as lighting for a flash in telephoto photography, the first film 211 can reduce the light reflected at the entrance portion 12A of the first lens 11, and the subject can be illuminated with a narrow light distribution and high illuminance. The second film 212 covers the exit portion 12B of the first lens 11. In this embodiment, the second film 212 covers the upper convex surface 17. That is, the second film 212 covers the second surface 210B, which is the exit surface of the substrate 210. The second film 212 may further cover the upper concave surface 18 of the first lens 11. The third film 213 is provided on the second film 212. For example, the first film 211 contacts the entrance portion 12A, the second film 212 contacts the upper convex surface 17, and the third film 213 covers the upper convex surface 17 from above the second film 212.

[0048] (Second translucent member) Next, a specific configuration of the second light-transmissive member 202 will be described.

[0049] The second light-transmissive member 202 has a second lens 31 and a second support portion 38. The second lens 31 is disposed such that the lower surface of the second lens 31 faces the second surface 210B of the first lens 11, and refracts the light emitted from the emission portion 12B of the first lens 11 to emit the light within a desired irradiation range. The second light-transmissive member 202 is formed of a light-transmissive resin such as polycarbonate resin, acrylic resin, silicone resin, or epoxy resin, similar to the first light-transmissive member 201. The outer shape of the second light-transmissive member 202 is preferably a circle or an ellipse when viewed from above, and may be a polygon such as a rectangle or a hexagon.

[0050] The second lens 31 has a plurality of annular convex portions 34 facing the second surface 210B of the first lens 11. The plurality of annular convex portions 34 may have a Fresnel shape. The lens surface 32 has a central convex portion 33 and a plurality of annular convex portions 34. The central convex portion 33 has a convex shape on the first lens 11 side. The plurality of convex portions 34 are arranged concentrically around the optical axis C2 of the second lens 31 on the outside of the central convex portion 33, and have a convex shape on the first lens 11 side. The plurality of annular convex portions 34 are preferably arranged concentrically with respect to the central convex portion 33 in a top view, and have a shape that is annular along the shape of the central convex portion 33. In other words, preferably, if the central convex portion 33 is circular in a top view, the convex portion 34 has a circular annular shape in a top view, and if the central convex portion 33 is rectangular in a top view, the convex portion 34 has a rectangular annular shape in a top view. Lens surface 32 is preferably formed to a size that positions incident portion 12A and light guiding portion 21 of first lens 11 inside when viewed from above. The lower surface of second lens 31 may have a Fresnel lens surface.

[0051] The second light-transmissive member 202 has a flat surface 36 on its upper surface. The flat surface 36 is formed to be equal to or larger in size than the lens surface 32 when viewed from above. When the second light-transmissive member 202 is inserted into the opening 52 of the third support part 51, the flat surface 36 is formed to be flush with the upper surface of the third support part 51. The flat surface 36 may be textured or have fine irregularities.

[0052] The second support portion 38 is formed in an annular shape extending laterally from the outer edge of the second lens 31, and the upper surface is formed to be flush with the flat surface 36. The lower end surface of the second support portion 38 is located below the lower surface of the lens surface 32. In the second light-transmissive member 202, the second support portion 38 is formed closer to the center than the first leg portion 25b of the first lens 11. Since the lower end surface of the second support portion 38 is located below the lens surface 32, the first lens 11 and the second lens 31 are separated from each other. Therefore, interference between the first lens 11 and the second lens 31 can be reduced.

[0053] <Light emitting part> Next, a specific configuration of the light-emitting section 1 will be described. Fig. 7 is a cross-sectional view showing the light-emitting section. Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 6.

[0054] The light emitting units 1a to 1i have light emitting surfaces 7a to 7i on their upper surfaces, respectively. In the following description, the light emitting surfaces 7a to 7i may be collectively referred to as the light emitting surface 7. The light emitting unit 1 is mounted on the substrate 41 with its lower surface opposite to its upper surface as a mounting surface. The light emitting unit 1 has a light emitting element 2, a wavelength conversion member 4, and a covering member 5. The wavelength conversion member 4 is provided on the upper surface of the light emitting element 2. The covering member 5 covers the side surfaces of the light emitting element 2 and the wavelength conversion member 4. The upper surface of the wavelength conversion member 4 is exposed from the covering member 5. The upper surface of the wavelength conversion member 4 is the light emitting surface 7 (i.e., the main light extraction surface). Note that the side surfaces of the wavelength conversion member 4 may be exposed from the covering member 5. The shape (planar shape) of the light emitting unit 1 when viewed from above is, for example, a rectangle. The planar shape of the light emitting unit 1 may be a circle or an ellipse, or may be a polygon such as a triangle or a hexagon. The light emitting sections 1a to 1i may have the same configuration, or at least one member may have a different configuration. The light emitting sections 1a to 1i may be integrally formed with a covering member 5, thereby connecting them to each other.

[0055] The light emitting element 2 includes at least a pair of positive and negative element electrodes on its lower surface, and in this embodiment, a positive electrode 3P and a negative electrode 3N are provided. The light emitting element 2 is placed on a substrate 41, and an electrode 42 of the substrate 41 and the element electrodes of the light emitting element 2 are electrically connected. The light emitting element 2 is, for example, a semiconductor element, and includes semiconductors such as III-V group compound semiconductors and II-VI group compound semiconductors. Examples of compound semiconductors include In X Al Y Ga 1-X-YExamples of the compound semiconductor include nitride-based semiconductors such as InN, AlN, GaN, InGaN, AlGaN, and InGaAlN. The light-emitting element 2 is, for example, an LED (Light Emitting Diode) or an LD (Laser Diode). From the viewpoints of luminous efficiency and excitation of a phosphor described later, the light-emitting element 2 has an emission peak wavelength of preferably 400 nm or more and 530 nm or less, more preferably 420 nm or more and 490 nm or less, and even more preferably 440 nm or more and 475 nm or less.

[0056] The wavelength conversion member 4 is a plate-like member having a substantially rectangular shape in top view, and covers the upper surface of the light emitting element 2. The wavelength conversion member 4 includes a phosphor that converts the wavelength of at least a part of the light from the light emitting element 2. The wavelength conversion member 4 can be formed using a translucent resin material or an inorganic material such as ceramics or glass. As the resin material, a thermosetting resin such as a silicone resin, a silicone modified resin, an epoxy resin, or a phenolic resin can be used. In addition, a thermoplastic resin such as a polycarbonate resin, an acrylic resin, a methylpentene resin, or a polynorbornene resin can be used. In particular, a silicone resin or a modified resin thereof having excellent light resistance and heat resistance is preferable. Note that the translucency here refers to a property that allows 60% or more of the incident light to be transmitted. Furthermore, the wavelength conversion member 4 may contain a light diffusing material. As the wavelength conversion member 4, the above-mentioned resin material, ceramics, glass, etc. containing a phosphor, a sintered body of a phosphor, etc. can be used.

[0057] The phosphor contained in the wavelength conversion member 4 is an yttrium-aluminum-garnet phosphor (e.g., (Y,Gd)3(Al,Ga)5O 12 :Ce), lutetium aluminum garnet phosphors (e.g., Lu3(Al,Ga)5O 12 :Ce), terbium aluminum garnet phosphors (e.g., Tb3(Al,Ga)5O 12 :Ce), CCA phosphors (e.g., Ca 10 (PO4)6Cl2:Eu), SAE phosphors (e.g., Sr4Al14 O 25 :(Eu), chlorosilicate phosphors (e.g., Ca8MgSi4O 16 Cl2:Eu), silicate phosphors (e.g., (Ba,Sr,Ca,Mg)2SiO4:Eu), β-sialon phosphors (e.g., (Si,Al)3(O,N)4:Eu) or α-sialon phosphors (e.g., Ca(Si,Al) 12 (O,N) 16 :Eu) and other oxynitride phosphors, LSN phosphors (e.g., (La,Y)3Si6N 11 :Ce), BSESN phosphors (e.g., (Ba,Sr)2Si5N8:Eu), SLA phosphors (e.g., SrLiAl3N4:Eu), CASN phosphors (e.g., CaAlSiN3:Eu) or SCASN phosphors (e.g., (Sr,Ca)AlSiN3:Eu) and other nitride phosphors, KSF phosphors (e.g., K2SiF6:Mn), KSAF phosphors (e.g., K2(Si 1-x Al x )F 6-x :Mn (where x satisfies 0 < x < 1)), or fluoride phosphors such as MGF phosphors (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), quantum dots having a perovskite structure (e.g., (Cs,FA,MA)(Pb,Sn)(F,Cl,Br,I)3 (where FA and MA represent formamidinium and methylammonium, respectively)), II-VI group quantum dots (e.g., CdSe), III-V group quantum dots (e.g., InP), or quantum dots having a chalcopyrite structure (e.g., (Ag,Cu)(In,Ga)(S,Se)2) can be used. The above phosphors are particles. Also, one of these phosphors can be used alone, or two or more of these phosphors can be used in combination.

[0058] For example, when a blue light-emitting element is used as the light-emitting element 2, a light-emitting unit 1 that emits white light can be obtained because the wavelength conversion member 4 contains a yellow phosphor. The wavelength conversion member 4 may contain a light diffusing substance, and as the light diffusing substance, for example, titanium oxide, barium titanate, aluminum oxide, silicon oxide, etc. can be used.

[0059] The covering member 5 covers the side surfaces of the light emitting element 2 and the wavelength conversion member 4 directly or indirectly. The covering member 5 is preferably made of a member having a high light reflectance in order to improve the light extraction efficiency. The covering member 5 may be made of a resin material containing a light reflective substance such as a white pigment. Examples of the light reflective substance include titanium oxide, zinc oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, magnesium silicate, barium titanate, barium sulfate, aluminum hydroxide, aluminum oxide, zirconium oxide, silicon oxide, and the like. One of these may be used alone, or two or more of these may be used in combination. In addition, the resin material is preferably a resin material containing a thermosetting resin such as an epoxy resin, a silicone resin, a silicone modified resin, or a phenol resin as a main component. The covering member 5 may be made of a member having translucency to visible light as necessary.

[0060] (substrate) Next, a specific configuration of the substrate 41 will be described. The light-emitting unit 1 is mounted on the substrate 41. As shown in Fig. 7, the substrate 41 has an electrode 42 on its surface. The substrate 41 may also have an electrode 42 inside. The electrode 42 is connected to the electrodes 3P and 3N of the light-emitting unit 1 via a conductive adhesive member 62, whereby the substrate 41 and the light-emitting unit 1 are electrically connected to each other.

[0061] Substrate 41 includes an insulating material. As the insulating material, it is preferable to use a material that is difficult to transmit light emitted from light-emitting unit 1 and external light, and it is preferable to use a material that has a certain degree of strength. Specifically, substrate 41 can be made of ceramics such as alumina, aluminum nitride, and mullite, and resins such as phenol resin, epoxy resin, polyimide resin, BT resin (bismaleimide triazine resin), and polyphthalamide.

[0062] The electrode 42 may be made of copper, iron, nickel, tungsten, chromium, aluminum, silver, gold, titanium, palladium, rhodium, an alloy of these, etc. Furthermore, a layer of silver, platinum, aluminum, rhodium, gold, an alloy of these, etc. may be provided on the surface of the electrode 42 from the viewpoint of the wettability, light reflectivity, etc. of the conductive adhesive member 62.

[0063] (3rd support part) Next, a specific configuration of the third support portion 51 will be described. The third support portion 51 covers the first lens 11 from the side. The third support portion 51 has a second upper portion 51a and a second leg portion 51b. The second upper portion 51a is formed in an annular shape and has an opening portion 52. The side surface of the opening portion 52 and the side surface of the second support portion 38 of the second light-transmitting member 202 are bonded to each other. The second lens 31 and the second support portion 38 may be bonded as a two-color molded body, or may be bonded between the second lens 31 and the second support portion 38 via an adhesive member. In addition, the lower surface of the second upper portion 51a and the upper surface of the first upper portion 25a of the first support portion 25 are bonded to each other by an adhesive member 61B. The second leg portion 51b extends downward from the second upper portion 51a. The side surface of the second leg portion 51b and the side surface of the substrate 41 are bonded to each other by an adhesive member 61C. Adhesive materials such as resin or adhesive tape can be used as the adhesive members 61B and 61C. The third support portion 51 is preferably made of a light-shielding material, and is preferably made of a resin material or the like containing a filler such as a light-reflecting material or a light-absorbing material so as to limit the distribution direction of the light emitted from the light source device 200. The shape of the opening 52 may be a circle, an ellipse, a triangle, a rectangle, a hexagon, or the like when viewed from above.

[0064] [Method of manufacturing the light source device according to the second embodiment] Next, a method for manufacturing the light source device 200 according to the second embodiment will be described. Fig. 8 is a flowchart showing the method for manufacturing the light source device 200 according to the second embodiment. Figs. 9 to 11 are cross-sectional views showing the method for manufacturing the light source device 200 according to the second embodiment.

[0065] First, as shown in Fig. 9, a step of preparing a light-transmitting base material 210 having a first surface 210A (lower surface in Fig. 9) and a second surface 210B (upper surface in Fig. 9) is performed. In this embodiment, the base material 210 includes a first lens 11. The first lens 11 can be obtained, for example, by molding a raw material (step S1). Next, a step of transferring the base material 210 to a jig is performed (step S2). A plurality of base materials 210 may be transferred to the jig.

[0066] Next, a process is performed (step S3) in which a translucent aluminum oxide film 212X containing aluminum oxide having a lower crystallinity than α-alumina is formed by ALD to cover the first surface 210A and the second surface 210B of the base material 210. The aluminum oxide film 212X can be formed by a method similar to that of the aluminum oxide film 112X in the first embodiment.

[0067] 10, a step is performed (step S4) in which a silicon oxide film is formed by sputtering as a light-transmitting third film 213 on the aluminum oxide film 212X of the second surface 210B to obtain an intermediate structure 214. The intermediate structure 214 includes a base material 210, an aluminum oxide film 212X formed on the first surface 210A of the base material 210, and an aluminum oxide film 212X and a third film 213 formed on the second surface 210B of the base material 210. The third film 213 can be formed by a method similar to that of the third film 113 in the first embodiment.

[0068] Next, a step of hydrating the intermediate structure 214 is performed (step S5). In this step, the intermediate structure 214 is hydrated to convert the aluminum oxide film 212X into a first film 211 containing hydrated alumina and disposed on the first surface 210A, and a second film 212 containing aluminum oxide having a lower crystallinity than α-alumina and disposed on the second surface 210B, as shown in Fig. 11. The hydration can be performed by a method similar to that of the hydration in the first embodiment.

[0069] Next, a step of drying the intermediate structure 214 after the hydration treatment is performed (Step S6). This allows the first light-transmissive member 201 including the first lens 11 to be prepared. Then, the dried first light-transmissive member 201 is transferred from the jig to a tray (Step S7). In the step of arranging the first light-transmissive member 201 in Step S7, a jig such as a suction nozzle is brought into contact with the third film 213 to transport the first light-transmissive member 201.

[0070] In this embodiment, the method further includes a step of arranging the second light-transmissive member 202 on the first light-transmissive member 201. For example, the light-emitting unit 1, the substrate 41 on which the light-emitting unit 1 is mounted, and the second light-transmissive member 202 supported by the third support unit 51 are prepared, and these are assembled with the first light-transmissive member 201 including the first lens 11 (step S8). In step S8, first, the second light-transmissive member 202 is arranged on the first lens 11 via the adhesive member 61B so that the lower surface of the second lens 31 having a plurality of annular convex portions, for example, the lens surface 32, faces the second surface 210B of the first lens 11. As a result, the second light-transmissive member 202 has a plurality of annular convex portions on the surface facing the first light-transmissive member 201. The light-emitting unit 1 is mounted on the substrate 41, and the first light-transmissive member 201 is fixed to the substrate 41 so that the first light-transmissive member 201 is disposed in the path of light emitted by the light-emitting unit 1. The first light-transmissive member 201 is disposed in the first lens 11 so that light emitted by the light-emitting unit 1 enters the first surface 210A of the first lens 11 and exits from the second surface 210B.

[0071] In this manner, the light source device 200 according to the second embodiment can be manufactured.

[0072] In the second embodiment, in the first lens 11, the first film 211 containing hydrated alumina covers the lower surface of the base material 210 facing the light emitting units 1a to 1i. Since hydrated alumina contains fine irregularities, it is possible to reduce reflection on the lower surface and improve the illuminance in the light source device 200. In addition, the second film 212 covers the upper surface of the base material 210, and the third film 213 is provided on the second film 212, and the hardness of the third film 213 is higher than the hardness of the second film 212. Therefore, when assembling the light source device 200, the first light-transmissive member 201 including the first lens 11 is transferred so that a jig such as a suction nozzle contacts the third film 113, thereby reducing the occurrence of scratches on the first film 211 and the second film 212. Therefore, it is possible to reduce the deterioration of optical characteristics due to the occurrence of scratches.

[0073] Since the critical angle between the substrate 210 and the air depends on the difference in transmittance between the substrate 210 and the air, the critical angle between the substrate 210 and the air does not change regardless of the presence or absence of the first film 211. If the light emitted from the light-emitting unit 1 is reflected at the critical angle between the substrate 210 (here, the first lens 11) and the air, it is reflected inside the light source device 200 and enters the substrate 210 again. At this time, the first film 111 makes it easier for the light to pass through the substrate 210, thereby reducing stray light.

[0074] <Third embodiment> Next, a third embodiment will be described. The third embodiment relates to a light source device. Fig. 12 is a cross-sectional view showing a light source device according to the third embodiment. Fig. 13 is a bottom view showing a lens and a support in the third embodiment. The light source device 300 according to the third embodiment differs from the light source device 200 according to the second embodiment in the shape of the lens 81 of the first light-transmissive member 301, the shape of the second light-transmissive member 302, and the area in which the first light-transmissive film 511, the second light-transmissive film 512, and the third light-transmissive film 513 are arranged on the first light-transmissive member 301.

[0075] The first light-transmissive member 301 includes a light-transmissive base material 310 including a lens 81. The base material 310 has an entrance portion 13A on a first surface 310A of the lens 81, where light from the light-emitting unit 1 is incident, and an exit portion 13B on a second surface 310B of the lens 81, where light transmitted through the lens 81 exits. The second light-transmissive member 302 is a plate-like member having flat upper and lower surfaces, and is disposed in the opening 52 of the third support portion 51 so as to overlap with the lens 81 of the first light-transmissive member 301 in a top view.

[0076] The first light-transmissive member 301 has a light-transmissive first film 311 on a first surface 310A of the lens 81, and a light-transmissive second film 312 and a light-transmissive third film 313 on a second surface 310B of the lens 81. The light-transmissive first film 311, the light-transmissive second film 312, and the light-transmissive third film 313 are provided in an area of ​​the first light-transmissive member 301 excluding the first support portion 25. As shown in FIG. 13, the outer shape of the lens 81 and the first support portion 25 (first leg portion 25b) is preferably a circle or an ellipse in a top view, and may be a polygon such as a rectangle or a hexagon. The lens 81 has a shape in which a plurality of annular convex portions 315 and annular convex portions 316 are concentrically arranged around the optical axis C3 of the lens 81 at the entrance portion 13A. Of the multiple convex portions 315, the distance from the substrate 41 to the tip of the convex portion 315 is smaller for the convex portion 315 closer to the optical axis C3 of the lens 81. The first surface 310A of the lens 81 has a convex shape toward the substrate 41 as a whole. The multiple convex portions 316 are arranged so as to surround the entire circumference of the multiple convex portions 315. The distance between the tip of each of the multiple convex portions 316 constituting the multiple convex portions and the substrate 41 is approximately equal. Note that the lens 81 may be a Fresnel lens including multiple convex portions 316 that are concentrically arranged about the optical axis C3 of the lens 81.

[0077] The light source device 300 according to the third embodiment can also provide the same effects as those of the second embodiment. In this embodiment, the first surface 310A of the lens 81 has a shape in which a plurality of annular convex portions 315 and convex portions 316 are concentrically arranged, so that the light-emitting unit 1 is difficult to see even when the light source device 300 is viewed from the second surface 310B side, and the appearance can be improved.

[0078] <Fourth embodiment> Next, a fourth embodiment will be described. The fourth embodiment relates to a light source device. Fig. 14 is a cross-sectional view showing the light source device according to the fourth embodiment. Fig. 15 is a bottom view showing the lens and support in the fourth embodiment. In the light source device 400 according to the fourth embodiment, the shape of the lens 82 of the first light-transmissive member 401 is different from that of the light source device 300 according to the third embodiment.

[0079] The first light-transmissive member 401 includes a light-transmissive base material 410 including a lens 82. The base material 410 has, on a first surface 410A of the lens 82, an entrance portion 14A where light from the light-emitting unit 1 is incident, and, on a second surface 410B of the lens 82, an exit portion 14B where the light transmitted through the lens 82 exits.

[0080] The first light-transmissive member 401 has a light-transmissive first film 411 on a first surface 410A of the lens 82, and a light-transmissive second film 412 and a light-transmissive third film 413 on a second surface 410B of the lens 82. As shown in FIG. 15, the outer shape of the lens 82 and the first support portion 25 (first leg portion 25b) is preferably a circle or an ellipse when viewed from above, and may be a polygon such as a rectangle or a hexagon. The lens 82 has a shape in which a plurality of annular convex portions 416 are arranged concentrically around the optical axis C4 of the lens 82 at the entrance portion 14A. The plurality of annular convex portions 416 may form a Fresnel lens. The distance of the tip of the convex portion 416 from the substrate 41 is smaller for the convex portion 416 closer to the optical axis C4 of the lens 82. The first surface 410A of the lens 82 has a convex shape toward the substrate 41 as a whole. Further, second surface 410B of lens 82 is a convex surface that protrudes toward the opposite side to substrate 41.

[0081] The light source device 400 according to the fourth embodiment can also provide the same effects as those of the second embodiment. Moreover, in this embodiment, the first surface 410A of the lens 82 has a shape in which a plurality of annular convex portions 416 are concentrically arranged, so that the light-emitting unit 1 is difficult to see even when the light source device 400 is viewed from the second surface 410B side, and the appearance can be improved.

[0082] <Fifth embodiment> Next, a fifth embodiment will be described. The fifth embodiment relates to a light source device. Fig. 16 is a cross-sectional view showing the light source device according to the fifth embodiment. Fig. 17 is a bottom view showing the lens and support in the fifth embodiment. The light source device 500 according to the fifth embodiment differs from the light source device 300 according to the third embodiment in the shape of the lens 83 of the first light-transmissive member 501.

[0083] The first light-transmissive member 501 includes a light-transmissive base material 510 including a lens 83. The base material 510 has, on a first surface 510A of the lens 83, an entrance portion 15A where light from the light-emitting unit 1 is incident, and, on a second surface 510B of the lens 83, an exit portion 15B where the light transmitted through the lens 83 exits.

[0084] The first light-transmissive member 501 has a light-transmissive first film 511 on a first surface 510A including the lens 83 and the third support portion 51, and has a light-transmissive second film 512 and a light-transmissive third film 513 on a second surface 510B including the lens 83 and the third support portion 51. As shown in FIG. 17, the outer shape of the lens 83 and the first support portion 25 (first leg portion 25b) is preferably a circle or an ellipse when viewed from above, and may be a polygon such as a rectangle or a hexagon. The lens 83 has a lower convex surface 514 that is disposed at the center of the entrance portion 15A and is convex toward the light-emitting portion 1, and a plurality of annular convex portions 516 that are concentrically disposed around the lower convex surface 514 with the optical axis C5 of the lens 83 as the center. The plurality of annular convex portions 516 may form a Fresnel lens. Of the multiple convex portions 516, the distance from the substrate 41 to the tip of the convex portion 516 is smaller for the convex portion 516 closer to the optical axis C5 of the lens 83. A first surface 510A of the lens 83 has an overall convex shape toward the substrate 41. In addition, a second surface 510B of the lens 83 is a convex surface that protrudes toward the opposite side to the substrate 41.

[0085] The light source device 500 according to the fifth embodiment can also provide the same effects as those of the second embodiment. In this embodiment, the first surface 510A of the lens 83 has a shape in which a plurality of annular protrusions 516 are concentrically arranged, so that even when the light source device 500 is viewed from the second surface 310B side, the inside of the light source device 500 is difficult to see, and the appearance can be improved.

[0086] <Example> Next, an experiment conducted by the inventor of the present application will be described. In this experiment, four types of samples including lenses were prepared. The first sample was a first light-transmitting member including a biconvex lens as shown in FIG. 5, and was prepared by the processes of steps S1 to S6 in FIG. 8. The first film 211 was an alumina hydrate film, the second film 212 was an aluminum oxide film having a lower crystallinity than α-alumina, and the third film 213 was a silicon oxide film. The second sample was composed only of the base material 210 including the biconvex lens, and was prepared by the process of step S1 in FIG. 8. The third and fourth samples were configured as follows.

[0087] The third sample is different from the first sample in that it does not have the first film and the second film. Specifically, in the third sample, a silicon oxide film is arranged in contact with the first surface of the base material 210. In addition, a silicon oxide film is arranged in contact with the second surface of the base material 210.

[0088] The fourth sample differs from the first sample in that it does not have the first film and the second film. Specifically, in the fourth sample, an α-alumina film, a silicon oxide film, an α-alumina film, and a silicon oxide film are arranged on the first surface of the base material 210 in this order from the first surface side. Also, an α-alumina film, a silicon oxide film, an α-alumina film, and a silicon oxide film are arranged on the second surface of the base material 210 in this order from the second surface side.

[0089] Next, the methods of fabricating the third and fourth samples will be described. Fig. 18 is a flow chart showing the method of fabricating the third sample. Fig. 19 is a flow chart showing the method of fabricating the fourth sample.

[0090] In the preparation of the third sample, first, a step of preparing a base material 210 including a lens was performed. The base material 210 was prepared by molding a raw material (step S11). Next, a step of transferring the base material 210 to a jig was performed (step S12).

[0091] Next, a process of forming a silicon oxide film on the first surface and the second surface of the base material 210 at a film formation temperature of about 100° C. by the ALD method was performed (step S13).

[0092] In this manner, the third sample was prepared.

[0093] In the preparation of the fourth sample, first, a step of preparing a base material 210 including a lens was performed. The base material 210 was prepared by molding a raw material (step S21). Next, a step of transferring the base material 210 to a jig was performed (step S22).

[0094] Next, a step of forming an α-alumina film on the first and second surfaces of substrate 210 was carried out (Step S23).

[0095] Next, a step of forming a silicon oxide film on the α-alumina film formed on the first and second surfaces was carried out (Step S24).

[0096] Next, a step of forming an α-alumina film on the silicon oxide film formed on the first surface and the second surface was carried out (Step S25).

[0097] Next, a step of forming a silicon oxide film on the α-alumina film formed on the first surface and the second surface was carried out (Step S26).

[0098] In the preparation of the fourth sample, the α-alumina film was formed by the ALD method at a film formation temperature of about 100°C, and the silicon oxide film was formed by the ALD method at a film formation temperature of about 100°C.

[0099] In this manner, the fourth sample was prepared.

[0100] Then, the optical properties and scratch resistance of the first, second, third and fourth samples were evaluated. In the evaluation of the optical properties, the light extraction efficiency of the lens itself and the light extraction efficiency of the light source device including the lens were measured. In the evaluation of the optical properties, one light emitting unit including a light emitting element with an emission peak wavelength of 450 nm, a wavelength conversion member provided on the light emitting element, and a coating member that covers the side surface of the light emitting element and the side surface of the wavelength conversion member was used. The light emitting unit emitted white light by mixing the light of the light emitting element and the light whose wavelength was converted by the wavelength conversion member. In the evaluation of scratch resistance, the light source device was assembled, and after carrying out one and three times of transportation simulating the transfer of the lens to the tray, the presence or absence of scratches on the light-transmitting film provided on the second surface of the lens was confirmed. In carrying the lens to the tray, the lens was adsorbed from the second surface side by a suction pad made of rubber at about 2N. The results are shown in Table 1. The numerical values ​​in the column for evaluation of optical properties in Table 1 indicate the relative light extraction efficiency when the light extraction efficiency of the second sample is set to 100.0%.

[0101] [Table 1]

[0102] As shown in Table 1, the first sample has a first film containing brittle hydrated alumina on the first surface, while a third film having a higher hardness than the first and second films is on the second surface. Therefore, when the first light-transmissive member is conveyed by bringing a jig such as a suction nozzle into contact with the third film during assembly of the light source device, the surface of the first light-transmissive member is not scratched, and the first sample has a scratch resistance as good as that of the third and fourth samples. Furthermore, the first sample has a higher light extraction efficiency than the third and fourth samples. This is because a hydrated alumina film is provided as the first film on the first surface of the substrate 210, which is the light incidence surface.

[0103] In this experiment, the first film containing hydrated alumina was provided on the first surface of the base material 210, which is the light incident surface, but the first film containing hydrated alumina may be provided on the second surface of the base material 210, which is the light exit surface, and a third film may be provided on the first surface of the base material 210, which is the light incident surface. In this case, in assembling the light source device, the first light-transmissive member is conveyed by bringing a jig such as a suction nozzle into contact with the third film provided on the first surface, thereby similarly reducing the occurrence of scratches on the surface of the first light-transmissive member. In addition, by having the first film containing hydrated alumina on the second surface of the first light-transmissive member, which is the light exit surface, the light extraction efficiency can be improved as in the first sample.

[0104] Although the preferred embodiments have been described in detail above, the present disclosure is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0105] The light-transmitting member and the light source device according to the embodiment of the present disclosure have excellent light extraction efficiency, and therefore can be suitably used as a flash light source and a headlight light source as a vehicle lamp. In addition, the light-transmitting member and the light source device according to the embodiment of the present disclosure can be used as a backlight light source for a liquid crystal display, various lighting fixtures, a large display, various display devices such as advertisements and destination guidance, etc. However, the light source device according to the present disclosure is not limited to these applications.

[0106] This specification includes the following embodiments. 1. a light-transmitting substrate having a first surface and a second surface opposite to the first surface; a light-transmitting first film covering the first surface; a light-transmitting second film covering the second surface; a light-transmitting third film provided on the second film; having the first membrane comprises hydrated alumina; the second film contains aluminum oxide having a lower crystallinity than α-alumina; The third film has a higher hardness than the second film. 2. 2. The light-transmitting member according to 1 above, wherein the first film has a thickness of 200 nm or more and 300 nm or less. 3. 3. The light-transmitting member according to 1 or 2 above, wherein the second film has a thickness of 25 nm or more and 45 nm or less. 4. 4. The light-transmitting member according to any one of 1 to 3 above, wherein the third film includes a silicon oxide film having a thickness of 80 nm or more and 135 nm or less. 5. 5. The light-transmitting member according to any one of 1 to 4 above, wherein the first surface and the second surface include a convex surface. 6. 6. The light-transmitting member according to any one of 1 to 5 above, wherein the first surface has a total reflection surface. 7. 7. The light-transmitting member according to any one of 1 to 6 above, wherein the substrate is a lens. 8. A light emitting portion; 8. The light-transmitting member according to any one of 1 to 7 above, which is disposed in a path of light emitted by the light-emitting unit; A light source device having the above structure. 9. the substrate is a lens, The light emitting portion has a light emitting surface, 9. The light source device according to claim 8, wherein the first film, the optical axis of the lens, and the light emitting surface overlap in a top view. 10. 10. The light source device according to claim 8 or 9, wherein the light is incident on the first surface of the base material and is emitted from the second surface of the base material. 11. 11. The light source device according to any one of claims 8 to 10, wherein the light source device is for use as a flash. 12. A method for manufacturing a light-transmitting member including a first film, a second film, and a third film, comprising the steps of: providing a light-transmitting substrate having a first surface and a second surface opposite the first surface; forming a light-transmitting aluminum oxide film covering the first surface and the second surface and including aluminum oxide having a crystallinity lower than that of α-alumina; forming a light-transmitting third film on the aluminum oxide film on the second surface to obtain an intermediate structure; a step of hydrating the intermediate structure to convert the aluminum oxide film into a first film including hydrated alumina and disposed on the first surface, and a second film including aluminum oxide having a lower crystallinity than α-alumina and disposed on the second surface; The manufacturing method of the light-transmitting member according to the present invention comprises the steps of: 13. 13. The method for producing a light-transmitting member according to claim 12, wherein in the step of hydrating the intermediate structural body, the intermediate structural body is exposed to liquid having a temperature of 70° C. or higher and 100° C. or lower, or water containing water vapor. 14. 14. The method for producing a light-transmitting member according to claim 12 or 13, wherein in the step of forming the aluminum oxide film, the aluminum oxide is formed by atomic layer deposition. 15. 15. The method for producing a light-transmitting member according to any one of 12 to 14, wherein in the step of hydrating the intermediate structural body, the hardness of the third film is made higher than the hardness of the second film. 16. 16. The method for producing a light-transmitting member according to any one of the above 12 to 15, wherein in the step of obtaining the intermediate structural body, the third film is formed by a sputtering method. 17. 17. The method for producing a light-transmitting member according to any one of the above 12 to 16, wherein the third film includes a silicon oxide film having a thickness of 80 nm or more and 135 nm or less. 18. 18. The method for producing a light-transmitting member according to any one of 12 to 17 above, wherein the substrate is a lens. 19. preparing a light-transmitting member manufactured by the manufacturing method according to any one of 12 to 18 above as a first light-transmitting member; preparing a light emitting unit; arranging the first light-transmissive member in a path of light emitted by the light-emitting portion; The manufacturing method of the light source device having the above structure. 20. 20. The method for manufacturing a light source device according to claim 19, wherein the first light-transmissive member is arranged so that the light is incident on the first surface of the base and exits from the second surface. twenty one. 21. The method for manufacturing a light source device according to claim 19 or 20, wherein the step of arranging the first light-transmissive member includes the step of bringing a jig into contact with the third film and transporting the first light-transmissive member. twenty two. The method further includes a step of disposing a second light-transmissive member on the first light-transmissive member, 22. The method for manufacturing a light source device according to any one of 19 to 21 above, wherein the second light-transmissive member has a plurality of annular protrusions on a surface facing the first light-transmissive member. [Explanation of symbols]

[0107] 1, 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i: Light-emitting part 2: Light emitting element 4: Wavelength conversion material 5: Covering material 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7h, 7i: Light emitting surface 10:Light source 11: First lens 31: Second lens 81, 82, 83: Lens 100: Translucent material 201, 301, 401, 501: First translucent member 202, 302: Second translucent member 110, 210, 310, 410, 510: Base material 110A, 210A, 210a: 1st side 110B, 210B, 210b: 2nd side 111, 211, 311, 411, 511: 1st membrane 112, 212, 312, 412, 512: Second membrane 112X, 212X: Aluminum oxide film 113, 213, 313, 413, 513: Third membrane 114, 214: Intermediate structure 200, 300, 400, 500: Light source device C1, C2, C3, C4, C5: Optical axis of the lens R: Center of the light-emitting part

Claims

1. a light-transmitting substrate having a first surface and a second surface opposite to the first surface; a light-transmitting first film covering the first surface; a light-transmitting second film covering the second surface; a light-transmitting third film provided on the second film; having the first membrane comprises hydrated alumina; the second film contains aluminum oxide having a lower crystallinity than α-alumina; The third film has a higher hardness than the second film.

2. The light-transmitting member according to claim 1 , wherein the first film has a thickness of 200 nm or more and 300 nm or less.

3. The light-transmitting member according to claim 1 , wherein the second film has a thickness of 25 nm or more and 45 nm or less.

4. The light-transmitting member according to claim 1 , wherein the third film includes a silicon oxide film having a thickness of 80 nm to 135 nm.

5. The light-transmitting member according to claim 1 , wherein the first surface and the second surface include a convex surface.

6. The light-transmitting member according to claim 1 , wherein the first surface comprises a total reflection surface.

7. The light-transmitting member according to claim 1 , wherein the substrate is a lens.

8. A light emitting portion; the light-transmitting member according to claim 1 or 2, which is disposed in a path of light emitted by the light-emitting portion; A light source device having the above structure.

9. the substrate is a lens, The light emitting portion has a light emitting surface, The light source device according to claim 8 , wherein the first film and an optical axis of the lens overlap with the light emitting surface when viewed from above.

10. The light source device according to claim 8 , wherein the light is incident on the first surface of the base material and is emitted from the second surface of the base material.

11. The light source device according to claim 8 , wherein the light source device is for use in a flash.

12. A method for manufacturing a light-transmitting member including a first film, a second film, and a third film, comprising the steps of: providing a light-transmitting substrate having a first surface and a second surface opposite the first surface; forming a light-transmitting aluminum oxide film covering the first surface and the second surface and including aluminum oxide having a crystallinity lower than that of α-alumina; forming a light-transmitting third film on the aluminum oxide film on the second surface to obtain an intermediate structure; a step of hydrating the intermediate structure to convert the aluminum oxide film into a first film including hydrated alumina and disposed on the first surface, and a second film including aluminum oxide having a lower crystallinity than α-alumina and disposed on the second surface; The manufacturing method of the light-transmitting member according to the present invention comprises the steps of:

13. The method for manufacturing a light-transmitting member according to claim 12 , wherein in the step of hydrating the intermediate structural body, the intermediate structural body is exposed to a liquid having a temperature of 70° C. or higher and 100° C. or lower, or water containing water vapor.

14. The method for manufacturing a light-transmitting member according to claim 12 or 13, wherein in the step of forming the aluminum oxide film, the aluminum oxide is formed by atomic layer deposition.

15. The method for manufacturing a light-transmitting member according to claim 12 or 13, wherein in the step of hydrating the intermediate structural body, a hardness of the third film is made higher than a hardness of the second film.

16. The method for producing a light-transmitting member according to claim 12 or 13, wherein in the step of obtaining the intermediate structural body, the third film is formed by a sputtering method.

17. The method for manufacturing a light-transmitting member according to claim 12 or 13, wherein the third film includes a silicon oxide film having a thickness of 80 nm or more and 135 nm or less.

18. The method for producing a light-transmitting member according to claim 12 or 13, wherein the substrate is a lens.

19. preparing a light-transmitting member manufactured by the manufacturing method according to claim 12 or 13 as a first light-transmitting member; preparing a light emitting unit; arranging the first light-transmissive member in a path of light emitted by the light-emitting portion; The manufacturing method of the light source device having the above structure.

20. The method for manufacturing a light source device according to claim 19 , wherein the first light-transmissive member is disposed such that the light is incident on the first surface of the base and is emitted from the second surface.

21. 20. The method for manufacturing a light source device according to claim 19, wherein the step of arranging the first light-transmissive member includes the step of bringing a jig into contact with the third film and transporting the first light-transmissive member.

22. The method further includes a step of disposing a second light-transmissive member on the first light-transmissive member, The method for manufacturing a light source device according to claim 19 , wherein the second light-transmissive member has a plurality of annular convex portions on a surface facing the first light-transmissive member.

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