Diffusion plate, light-emitting device, and sensor module

Abstract

A diffusion plate (10) comprises a microlens array (110) in which a plurality of convex lenses (11) are aligned, and a glass substrate (120) that is bonded to the microlens array (110) via an adhesive layer (130). The adhesive layer (130) has an end (131) positioned outside the outer edge of the microlens array (110) in a plan view. The end (131) of the adhesive layer (130) may also be positioned outside the outer edge of the substrate (120) in a plan view. Furthermore, the end (131) of the adhesive layer (130) may have a surface inclined obliquely with respect to a first direction along the layering direction of the substrate (120) and the microlens array (110).

Description

Diffuser, light-emitting device and sensor module

[0001] The present disclosure relates to a diffuser plate, a light-emitting device, and a sensor module.

[0002] Japanese Patent Application Laid-Open No. 2015-141908 discloses a diffuser plate in which a microlens array in which a plurality of convex lenses are arranged is bonded onto a substrate with a bonding member.

[0003] One aspect of the present disclosure is as follows: [1] A diffuser plate comprising: a microlens array having a plurality of convex lenses arranged; and a substrate bonded to the microlens array via an adhesive layer, wherein the adhesive layer has an end portion located outside the outer edge of the microlens array in a planar view. [2] The diffuser plate of [1], wherein the end portion of the adhesive layer is further located outside the outer edge of the substrate in a planar view. [3] The diffuser plate of [1] or [2], wherein the end portion of the adhesive layer has a surface inclined obliquely with respect to a first direction along a stacking direction of the substrate and the microlens array. [4] The diffuser plate of any one of [1] to [3], wherein at least a portion of a tip of the end portion of the adhesive layer is located away from the midpoint of the adhesive layer in the first direction along the stacking direction of the substrate and the microlens array. [5] The diffuser plate of any one of [1] to [4], wherein the end portion of the adhesive layer includes a curved portion in a cross section including the first direction along the stacking direction of the substrate and the microlens array. [6] The diffuser plate according to any one of [1] to [5], wherein the end of the adhesive layer has a portion with an asymmetric shape with respect to a midpoint of the adhesive layer in the first direction in a cross section including a first direction along the stacking direction of the substrate and the microlens array. [7] The diffuser plate according to any one of [1] to [6], wherein the end of the adhesive layer contacts a side surface of the substrate. [8] The diffuser plate according to any one of [1] to [6], wherein the end of the adhesive layer contacts a side surface of the microlens array. [9] The diffuser plate according to any one of [1] to [6], wherein the end of the adhesive layer contacts a side surface of the substrate and a side surface of the microlens array.

[10] The diffuser plate according to any one of [1] to [9], wherein the microlens array and the substrate are rectangular in a plan view, and the adhesive layer has a protruding portion protruding from a corner of a rectangular reference range that is larger than the rectangular range of the microlens array in a plan view.

[11] The diffuser plate according to

[10] , wherein the tip of the protruding portion is acute-angled.

[12] The diffusion plate of

[10] or

[11] , wherein the tip of the protruding portion is off from an extension line of a bisector of a corner where the protruding portion of the microlens array protrudes in a plan view.

[13] The diffuser according to any one of

[10] to

[12] , wherein the adhesive layer has a pair of protruding portions protruding from two adjacent corners in the reference range.

[14] The diffuser according to

[13] , wherein tips of the pair of protruding portions are located in the same region among four regions outside the reference range defined by extending the bisectors of the four corners of the microlens array in a planar view.

[15] The diffuser according to

[14] , wherein the adhesive layer extends outward from the reference range at two corners other than the two corners.

[16] The diffuser according to

[13] , wherein tips of the pair of protruding portions are located in regions symmetrical with respect to the reference range among four regions outside the reference range defined by extending the bisectors of the four corners of the microlens array in a planar view.

[17] The diffuser according to

[16] , wherein the adhesive layer extends outward from the reference range at two corners other than the two corners.

[18] The diffusion plate according to any one of

[13] to

[17] , wherein the edge of the protruding portion includes a curved portion in a plan view.

[19] A light-emitting device comprising: the diffusion plate according to any one of [1] to

[18] , a light-emitting element that emits light to be incident on the diffusion plate, and a housing that is joined to the diffusion plate and seals the light-emitting element therein.

[20] A sensor module comprising: the light-emitting device of

[19] , and a light-receiving device that detects incident light.

[0004] 1 is a schematic cross-sectional view of a sensor module including a light-emitting device using a diffuser plate; FIG. 2 is a contour map of the surface of the diffuser plate as viewed from the bottom side; FIG. 3 is a cross-sectional view of the surface of the diffuser plate as viewed from the bottom side; FIG. 4 is a cross-sectional view showing another example of an edge shape; FIG. 5 is a cross-sectional view showing another example of an edge shape; FIG. 6 is a cross-sectional view showing another example of an edge shape; FIG. 7 is an enlarged cross-sectional view showing a detailed shape of the edge; FIG. 8 is an enlarged cross-sectional view showing a detailed shape of the edge; FIG. 9 is an enlarged cross-sectional view showing a detailed shape of the edge; FIG. 10 is a plan view showing another example of an edge shape of an adhesive layer; FIG. 11 is a plan view showing another example of an edge shape of an adhesive layer; FIG. 12 is a plan view showing another example of an edge shape of an adhesive layer; FIG. 13 is a plan view showing another example of an edge shape of an adhesive layer;

[0005] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings. Fig. 1 is a schematic cross-sectional view of a sensor module 100 including a light-emitting device 1 using a diffuser plate 10 according to the present embodiment.

[0006] The sensor module 100 includes a light-emitting device 1 and a light-receiving device 2. The light-emitting device 1 and the light-receiving device 2 are positioned side by side on a module substrate 3. The sensor module 100 is, for example, a photoelectric sensor that detects incident light that is emitted by the light-emitting device 1 and reflected by an object and enters the light-receiving device 2, thereby performing object detection, but is not limited to this.

[0007] The light-emitting device 1 includes a light-emitting element 15, a diffuser 10, and a housing 16. The light-emitting element 15 is a surface-emitting laser, such as a vertical-cavity surface-emitting laser (VCSEL). The housing 16 is a package having a shape with a recess with one open end, such as a box shape, in which the light-emitting element 15 is located. The housing 16 also has signal lines and connection terminals for supplying power related to light emission from an external source to the light-emitting element 15.

[0008] The diffuser plate 10 covers the open surface of the housing 16. The diffuser plate 10 may be fitted into the housing 16 and bonded to the housing 16 with a bonding material 17. The diffuser plate 10 diffuses the light emitted by the light-emitting element 15 and outputs it to the outside. The diffuser plate 10 will be described later. Here, the direction in which light can enter and exit the housing 16 through the diffuser plate 10 is defined as upward, and in the following description, the z-axis is defined so that upward is the +z direction. The +z direction is equal to the first direction.

[0009] The light-receiving device 2 includes a substrate 21, a light-receiving element 22, an optical member 23, and a support portion 24. The light-receiving element 22 is, for example, a photodiode. The light-receiving element 22 is capable of receiving incident light from above and is connected to a connection terminal on the substrate 21. The substrate 21 has a signal line that outputs a signal corresponding to the amount of received light to the outside, and one end of the signal line is connected to the connection terminal.

[0010] The optical member 23 may include a lens, a filter, or the like. The optical member 23 focuses light incident from above onto the entrance of the light-receiving element 22. The optical member 23 may also include a band-pass filter that selectively passes light in the wavelength band emitted by the light-emitting element 15 and blocks light of other wavelengths. The band-pass filter may also block light of other wavelengths outside the visible light range, such as infrared light. The support portion 24 supports the optical member 23. The support portion 24 may also function as a light-blocking member that prevents light from entering the light-receiving element 22 without passing through the optical member 23.

[0011] Next, the diffuser plate 10 will be described. FIG. 2A is a contour map of the surface of the diffuser plate 10 of this embodiment as seen from the bottom side. FIG. 2B is a cross-sectional view taken along the cross-sectional line AA. As shown in FIG. 2A, the diffuser plate 10 has a microlens array 110 in which a plurality of convex lenses 11 are regularly arranged. Each of the convex lenses 11 protrudes downward, i.e., in the −z direction, and diffuses light from light-emitting elements 15 located further in the −z direction of the microlens array 110, emitting the light approximately evenly over a wider range. In other words, the convex portions of the convex lenses 11 each protrude toward the inner surface of the housing 16.

[0012] The microlens array 110 is not particularly limited, but may be, for example, positioned on a glass substrate 120, which is a transparent flat plate, and have an uneven shape made of a transparent resin. The stacking direction of the microlens array 110 and the glass substrate 120 coincides with the z direction. The glass substrate 120 may be made of borosilicate glass. The thickness of the glass substrate 120 may be, for example, approximately 100 to 1000 μm. The transparent resin may be, for example, an acrylic resin, an epoxy resin, a silicone resin, or the like. Alternatively, the microlens array 110 and the flat plate portion of the diffuser 10 that corresponds to the glass substrate 120 may be integrally formed of a transparent resin. Furthermore, this transparent resin may contain carbon and metal oxides.

[0013] Here, the convex lenses 11 are arranged on the lattice points of a square lattice with the same number of columns and rows, and the microlens array 110 may have a rectangular shape in a plan view, particularly a square shape. The length of one side of the square may be, for example, 2 to 4 mm. However, the arrangement and size are not limited to those described above.

[0014] As shown in FIG. 2B , the convex lens 11 may be a wide-angle lens type having a large concave-convex shape relative to its width in a cross-sectional view taken along a cross section including the z-direction. This allows incident light from the light-emitting element 15 to easily enter the convex lens 11 at a large angle of incidence, resulting in a large change in the direction of the light at the lens surface. Light incident from each convex surface of the convex lens 11 does not need to converge to a single point. The upper surface on the +z side of the glass substrate is flat, and light that enters the rear surface of the diffuser plate 10 at a large angle of incidence is emitted to the outside from the surface of the diffuser plate 10 at an even larger angle of emission. Optical path L is shown as an example. The microlens array 110 and the glass substrate 120 may be the same size in a planar view.

[0015] The microlens array 110 and the glass substrate 120 are bonded to each other via an adhesive layer 130. The adhesive layer 130 is optically transparent. The adhesive layer 130 may be a thin layer so as to reduce a decrease in light transmittance. For example, the thickness of the adhesive layer 130 may be 50 to 100 μm. The adhesive may be, for example, a resin that hardens when irradiated with ultraviolet light. For example, the adhesive may be a polyurethane resin, an acrylic ester, or the like.

[0016] The adhesive layer 130 includes an end 131 located outside the outer edges of the microlens array 110 and the glass substrate 120 in a planar view. That is, the end 131 of the adhesive layer 130 protrudes from the periphery of the microlens array 110 in a planar view. The protrusion width may be approximately constant for each diffuser plate 10. "Approximately constant" means, for example, that the protrusion width at each point varies within a range of approximately ±30% from the average protrusion width. However, as described below, the end 131 may have a localized portion that significantly protrudes from a substantially constant reference range. Specifically, the protrusion width may be, for example, in a range of approximately 5 to 100 μm from the outer edges of the microlens array 110 and the glass substrate 120, including the significantly protruding portion. Having a wider planar view of the adhesive layer 130 than the microlens array 110 and the glass substrate 120, which are to be bonded, reduces the possibility of peeling between the microlens array 110 and the glass substrate 120. Furthermore, the end portion 131 is also bonded to the bonding material 17, thereby reducing the possibility that the diffusion plate 10 will peel off from the housing 16. Note that the end portion 131 itself has already solidified when it is bonded to the bonding material 17, and therefore the end portion 131 functions as an object to which the bonding material 17 is bonded.

[0017] 3A to 3C are cross-sectional views showing other examples of the shape of the end portion 131. As shown in Fig. 3A, the end portion 131 of the adhesive layer 130 may widen in the -z direction and come into contact with the side surface of the microlens array 110. This further reduces peeling between the adhesive layer 130 and the microlens array 110. Furthermore, by widening the thickness of the end portion 131, the contact area with the bonding material 17 increases, further reducing the possibility of the diffuser plate 10 peeling off from the housing 16.

[0018] 3B , the end 131 of the adhesive layer 130 may extend in the +z direction and contact the side surface of the glass substrate 120. This further reduces the possibility of peeling between the adhesive layer 130 and the glass substrate 120. Also in this case, the bonding between the end 131 and the bonding material 17 further reduces the possibility of peeling of the diffuser plate 10 from the housing 16.

[0019] 3C , the end 131 of the adhesive layer 130 may extend in the ±z direction and be in contact with both the side surface of the microlens array 110 and the side surface of the glass substrate 120. This increases the bonding strength between the adhesive layer 130 and the glass substrate 120 and the microlens array 110, as well as the bonding strength between the end 131 and the bonding material 17, further reducing the possibility of peeling.

[0020] 4A to 4C and 5A to 5C are enlarged cross-sectional views showing the detailed shape of the end 131. In these enlarged views, the r-direction is defined as the direction perpendicular to the z-direction and outwardly perpendicular to the outer edge of the microlens array 110, and the t-direction is defined as the direction perpendicular to the r-direction and z-direction. As shown in FIG. 4A, the end 131 tapers from the thickness of the adhesive layer 130 to a tip P. As shown in FIG. 4B, the tip P does not have to be a single point, i.e., a corner, in cross-sectional view. The tip P may be a series of continuous points, i.e., a line shorter than the thickness of the adhesive layer 130. In this case, the tip P may be located at a position deviating from the midpoint of the thickness of the adhesive layer 130, i.e., in the z-direction. Here, a position deviating from the midpoint means a deviation of 2% or more of the thickness of the adhesive layer 130. The position of the tip P in the z-direction does not have to be constant in the t-direction. When the diffusion plate 10 is heated, both the bonding material 17 and the adhesive layer 130 thermally expand, increasing the stress in the adhesive layer 130. At this time, because the end 131 has an irregular shape, stress is generated to one side at the end 131, making it easy to release the load.

[0021] In this case, at least one of the sides of the end 131 connected to the tip P, i.e., the three-dimensional faces, may be inclined obliquely with respect to the z direction. The oblique angle range here may be, for example, 10 to 70 degrees.

[0022] 4C , the end 131 may have four or more corners in a cross-sectional view. The end 131 may have an asymmetric shape with respect to the midpoint in the z direction, with the half closer to the microlens array 110 and the half closer to the glass substrate 120. Such an asymmetric shape is also effective in reducing the load corresponding to the bias of the stress during heating.

[0023] 5A and 5B, the cross-sectional shape of the end portion 131 may include portions other than straight lines. That is, the edge of the end portion 131 in the cross-sectional view may have curved portions. Since the tip P and the base of the outer edge of the end portion 131 are not connected by a straight line, the surface area of ​​the end portion 131 is increased. This improves the bonding strength between the end portion 131 and the bonding material 17.

[0024] In the above figures, the tip P is located closer to the microlens array 110 than the midpoint in the thickness direction of the adhesive layer 130, but as shown in Fig. 5C, the tip P may be located closer to the glass substrate 120 than the midpoint. Alternatively, the tip P may be located at the midpoint.

[0025] 6A and 6B are enlarged cross-sectional views showing the detailed shape of other examples of the end 131. As shown in FIG. 3 above, the end 131 may expand in the ±z direction and contact the side surface of the microlens array 110 and / or the side surface of the glass substrate 120. Even in this case, as shown in FIG. 6A, the tip P may be within the range of the adhesive layer 130 in the z direction, i.e., within a range from the midpoint to 50% or less of the thickness of the adhesive layer 130. Alternatively, as shown in FIG. 6B, the tip P may be outside the range of the adhesive layer 130 in the z direction.

[0026] 7A, 7B, 8A, 8B, and 9 are plan views showing other examples of the shape of the end portion 131. In these plan views, the specific lens structure of the microlens array 110 is omitted. As shown in FIG. 7A, the end portion 131 may include a protruding portion 1311 protruding from at least one corner of a rectangular, particularly square, reference range in a plan view. The reference range may not be strictly rectangular, but may have fine irregularities. For example, the reference range may be a position obtained by approximating the periphery of the end portion 131 with a square. The protruding portion 1311 has a significantly larger protrusion size than the fine irregularities. Specifically, the protruding portion 1311 may have an average deviation from the reference range, for example, a deviation larger than the standard deviation, and the absolute value of the size may be approximately 20 to 100 μm. When the protruding portion 1311 is further bonded to the bonding material 17, the bonding strength of the diffuser plate 10 to the housing 16 is improved. In particular, since the diffuser plate 10 is likely to peel off from the housing 16 at the corners, increasing the bonding strength at the corners can effectively reduce the possibility of the diffuser plate 10 peeling off from the housing 16. Note that such protruding portions 1311 may be bent toward the microlens array 110 or the glass substrate 120 and contact either side of the microlens array 110 or the glass substrate 120. This can improve the bonding strength of the diffuser plate 10 by the adhesive layer 130.

[0027] Furthermore, the tip C1 of the protruding portion 1311 does not have to be located on the diagonal of the square area when the microlens array 110 and the glass substrate 120 are viewed in plan, i.e., on an extension of the bisector of the corner where the tip C1 protrudes. Furthermore, when the protruding portion 1311 is approximated as a triangle, the angle formed by the tip C1 may be an acute angle of less than 90 degrees. The protruding portion 1311 having such a narrow tip C1 angle increases the surface area of ​​the protruding portion 1311 while reducing the reduction in surface area near the reference area at the base, thereby effectively increasing the bonding area with the bonding material 17. This increases the bonding strength of the diffuser plate 10 to the housing 16, reducing the possibility of the diffuser plate 10 peeling off.

[0028] As shown in FIG. 7B , the end 131 may have a pair of protruding portions 1311 and 1312 at two adjacent corners of a rectangular reference range in a planar view. The protruding widths of the protruding portions 1311 and 1312 may be approximately the same or different. The tip C1 of the protruding portion 1311 and the tip C2 of the protruding portion 1312 may both be located outside the bisector. Furthermore, the tips C1 and C2 may be located in the same area A1, one of four areas outside the reference range defined by the straight lines extending the four bisectors of the four corners. In other words, the angles formed by the tips C1 and C2 with respect to the intersection of the bisectors of the two corners where the tips C1 and C2 protrude are narrower than the angle of area A1. In other words, the extending directions of the protruding portions 1311 and 1312 may be biased in the same direction. As long as tips C1 and C2 are in the same region, they may be in any of regions A1 to A4. If the range extending outside the reference range and the distance from the corner of microlens array 110 or the like are the same, the angle q1 between the bisector of the corner of microlens array 110 and the line segment to tip C1 is large, and the sum of the lengths of the two sides is also large when the lengths of the two sides are different. Therefore, the bonding area between protrusions 1311 and 1312 and bonding material 17 increases, and the bonding strength between them increases.

[0029] 8A , the edge connecting the tip C1 of the protruding portion 1311 to the reference range may be curved. The curved edge may be the edge on the side away from the bisector closest to the tip C1. If the tip C1 and the reference range are not connected by a straight line, the length along the protruding portion 1311 to the tip C1 becomes longer, and this portion comes into contact with the side surface of the microlens array 110 or the glass substrate 120, thereby improving the bonding strength of the contacting portion.

[0030] 7B , the tips C1 and C2 of the protruding portions 1311 and 1312 located at two adjacent corners may be located in two symmetrical regions A2 and A4, respectively, among the four regions outside the reference range defined by the extensions of the two bisectors of the corners at which the protruding portions 1311 and 1312 protrude. That is, the angles formed by the tips C1 and C2 with respect to the intersection point are wider than the angle of region A1. Even in this case, the larger angle q1 and the larger the sum of the lengths of the two sides connecting the tips C1 and C2 with the base of the reference range are, the larger the bonding area with the bonding material 17 and the higher the bonding strength.

[0031] When the diffuser plate 10 is bonded to the housing 16, the protruding portions 1311 and 1312 may face in a direction different from that of the diffuser plate 10 alone, depending on the bonding conditions. The protruding portions 1311 and 1312 may not have a uniform structure in the z direction. For example, the protruding portions 1311 and 1312 may have different distances from the corners of the microlens array 110 to the tips C1 and C2 or different angles between the tips C1 and C2 depending on their positions in the z direction.

[0032] As shown in FIG. 9 , in addition to the two corners having protruding portions 1311 and 1312, the adhesive layer 130 may also have extensions 1313 and 1314 located outside the reference range near the other two corners of the end portion 131. The extension widths of the extensions 1313 and 1314 may be similar to those of the protruding portions 1311 and 1312. The shapes of these extensions 1313 and 1314 may be different from those of the protruding portions 1311 and 1312. Specifically, the extensions 1313 and 1314 may not have protruding tips. Furthermore, the extensions 1313 and 1314 may not have significant anisotropy on either side of the corresponding corner. In this case, the extensions 1313 and 1314 may rise at a small angle relative to the reference ranges of the regions A2 and A4, which are symmetrical to the reference range, and the sides of the microlens array 110. The small angle may be, for example, 45 degrees or less. These protrusions 1311, 1312 and extensions 1313, 1314 may be obtained as designed or may be generated during the manufacturing process.

[0033] As described above, the diffuser plate 10 of this embodiment includes a microlens array 110, a glass substrate 120, and an adhesive layer 130. The microlens array 110 has a plurality of convex lenses 11 arranged therein. The glass substrate 120 is bonded to the microlens array 110 via the adhesive layer 130. The adhesive layer 130 has an end 131 located outside the outer edge of the microlens array 110 in a planar view. Since the end 131 of the adhesive layer 130 is widened in this manner, when the diffuser plate 10 is bonded to the housing 16, this end 131 enables the diffuser plate 10 to be more firmly bonded to the housing 16. This reduces the likelihood of the diffuser plate 10 peeling off after being bonded to the housing 16.

[0034] Furthermore, the end 131 of the adhesive layer 130 may be located outside the outer edge of the glass substrate 120 in a plan view. By having the adhesive layer 130 located outside the outer edges of both the microlens array 110 and the glass substrate 120, the end 131 of the adhesive layer 130 can be firmly bonded to the housing 16 over a wider range. Therefore, the possibility of the diffuser plate 10 peeling off from the housing 16 is further reduced.

[0035] Furthermore, the end 131 of the adhesive layer 130 may have a surface that is inclined obliquely with respect to the z direction, which is the stacking direction of the glass substrate 120 and the microlens array 110. Since the bonding surface with the bonding material 17 is inclined, it is possible to more effectively reduce the possibility that the diffuser plate 10 will peel off and fall off from the fitted housing 16.

[0036] Furthermore, at least a portion of the tip P of the end 131 of the adhesive layer 130 may be located at a position offset from the midpoint of the adhesive layer 130 in the z direction, which is the direction along which the glass substrate 120 and the microlens array 110 are stacked. In this way, since the adhesive layer 130, particularly the end 131, has a structure offset in the z direction, even if the adhesive layer 130 and the bonding material 17 expand due to heat, such as when the bonding material 17 heat-bonds the diffuser plate 10 to the housing 16, stress is easily released outward. This reduces the load on the diffuser plate 10, thereby reducing the possibility of peeling or failure of the diffuser plate 10.

[0037] Furthermore, the end 131 of the adhesive layer 130 may include a curved portion in a cross section including the z direction along the stacking direction of the glass substrate 120 and the microlens array 110. That is, by bonding the end 131 and the bonding material 17 at a curved surface, the bonding area increases and the strength against lateral displacement and the like also increases, further reducing the possibility of peeling off of the diffuser plate 10.

[0038] Furthermore, the end 131 of the adhesive layer 130 may have a portion that is asymmetric in shape with respect to the midpoint of the adhesive layer 130 in the z direction when viewed in a cross section including the z direction, which is the stacking direction of the glass substrate 120 and the microlens array 110. The bonding material 17 and the adhesive layer 130 tend to expand when heated. At this time, the adhesive layer 130 side has an asymmetric shape in the z direction, which makes it easier to release stress and reduces excessive load on the diffuser plate 10.

[0039] Furthermore, the end 131 of the adhesive layer 130 may be in contact with the side surface of the glass substrate 120. Since the end 131 is bonded to the bonding material 17 in the immediate vicinity of the side surface of the diffuser plate 10, the diffuser plate 10 is bonded to the housing 16 more stably and firmly.

[0040] Furthermore, the end 131 of the adhesive layer 130 may be in contact with the side surface of the microlens array 110. In this case as well, the end 131 is bonded to the bonding material 17 in the immediate vicinity of the side surface of the diffuser plate 10, so that the diffuser plate 10 is more stably and firmly bonded to the housing 16.

[0041] Furthermore, the end 131 of the adhesive layer 130 may be in contact with the side surface of the glass substrate 120 and the side surface of the microlens array 110. When the end 131 is in contact with a wide area in the z direction from the side surface of the glass substrate 120 to the side surface of the microlens array 110, the bonding area between the end 131 and the bonding material 17 becomes larger, and the diffuser plate 10 is bonded to the housing 16 more firmly.

[0042] Furthermore, the microlens array 110 and the glass substrate 120 may be rectangular in plan view. The adhesive layer 130 may have protruding portions 1311 protruding from corners of a rectangular reference range that is larger than the rectangular range of the microlens array 110 in plan view. This makes the bonding surface with the bonding material 17 more complex and the protruding portions 1311 are bonded so as to be encompassed by the bonding material 17, thereby more firmly bonding the diffuser plate 10 to the housing 16.

[0043] Furthermore, the tip of the protruding portion 1311 may have an acute angle. The narrow protruding portion 1311 effectively expands the surface area of ​​the end portion 131, increasing the bonding area with the bonding material 17 and more firmly bonding the diffuser plate 10 to the housing 16. Furthermore, when the light-emitting device 1 including the diffuser plate 10 is heated, the load on the corner of the glass due to the thermal expansion of the bonding material 17 is reduced.

[0044] Furthermore, the tip P of the protruding portion 1311 may deviate from the extension line of the bisector of the angle of the protruding portion 1311 of the microlens array 110 in a planar view. The protruding portion 1311 has a shape similar to an asymmetrical triangle in a planar view, which results in a larger surface area than a symmetrical triangle. Therefore, the bonding material 17 is more firmly bonded to the diffuser plate 10, reducing the possibility of the diffuser plate 10 peeling off from the housing 16. Furthermore, this shape makes it easier to balance the glass substrate 120 when bonding the diffuser plate 10 to the housing 16 with the bonding material 17 to seal the interior. Therefore, the glass substrate 120 is more easily maintained parallel to the bottom surface of the housing 16 and fixed.

[0045] Furthermore, the adhesive layer 130 may have a pair of protruding portions 1311, 1312 that respectively protrude from two adjacent corners within the reference range. Such a pair of protruding portions 1311, 1312 firmly fixes both ends of one side of the diffuser plate 10, making that side less likely to peel off from the housing 16. Furthermore, this makes it easier to balance the glass substrate 120 during the sealing process, making it easier to fix the glass substrate 120 in an appropriate position relative to the housing 16.

[0046] Furthermore, the tips C1 and C2 of the pair of protruding portions 1311 and 1312 may be located in the same region, for example, region A1, among four regions A1 to A4 outside a reference range defined by extending the bisectors of the four corners of the microlens array 110 in a planar view. Because the protruding portions 1311 and 1312 extend in a direction inclined relative to the diagonal, the surface area increases as described above, and the bonding strength between the diffuser plate 10 and the housing 16 via the bonding material 17 increases. Even with this shape, the glass substrate 120 is more easily balanced when the diffuser plate 10 is bonded to the housing 16 via the bonding material 17 to seal the interior. Therefore, the glass substrate 120 is more easily fixed and kept parallel to the bottom surface of the housing 16.

[0047] The adhesive layer 130 may also have extensions 1313 and 1314 that extend outward from the reference range at two corners other than the two corners corresponding to the protruding portions 1311 and 1312. These extensions 1313 and 1314 allow the edge opposite to the edge corresponding to the protruding portions 1311 and 1312 to be more firmly bonded to the bonding material 17. This allows the diffuser plate 10 to be more firmly fixed to the housing 16 near the four corners, further reducing the possibility of the diffuser plate 10 peeling off from the housing 16. In this way, the diffuser plate 10 is supported at the four corners when bonded to the housing 16 by the bonding material 17, and therefore the diffuser plate 10 is more likely to be fixed to the housing 16 in the correct orientation.

[0048] Furthermore, the tips C1 and C2 of a pair of protruding portions 1311 and 1312 may be located in regions symmetrical with respect to a reference range, for example, regions A2 and A4, among four regions A1 to A4 outside the reference range defined by extending the bisectors of the four corners of microlens array 110 in a plan view. Even with protruding portions 1311 and 1312 oriented in this manner, both ends of one side of diffuser plate 10 are firmly bonded, thereby reducing the possibility of one side of diffuser plate 10 peeling off from housing 16. Furthermore, as described above, because protruding portions 1311 and 1312 extend asymmetrically with respect to the reference range, the surface area increases and they are more firmly connected to bonding material 17.

[0049] Furthermore, the edges of the protruding portions 1311 and 1312 may include curved portions in a plan view, which further increases the surface area of ​​the protruding portions 1311 and 1312, allowing the diffusion plate 10 to be more firmly bonded to the housing 16 and reducing the possibility of the diffusion plate 10 peeling off.

[0050] Furthermore, the light-emitting device 1 of this embodiment includes the above-described diffuser plate 10, light-emitting elements 15 that emit light to be incident on the diffuser plate 10, and a housing 16 that is bonded to the diffuser plate 10 and seals the light-emitting elements 15 inside. In this light-emitting device 1, the diffuser plate 10 is more firmly bonded, reducing the possibility of it peeling off from the housing 16. In particular, reducing the possibility of the diffuser plate 10 peeling off in the light-emitting device 1 reduces the possibility of light emitted by the light-emitting elements 15, particularly laser light, directly entering the field of view. Therefore, it is possible to reduce the occurrence of problems with the light-emitting device 1 that could have an adverse effect on the human body.

[0051] The sensor module 100 of this embodiment includes the light-emitting device 1 and the light-receiving device 2 that detects incident light. Therefore, the sensor module 100 can use the light-emitting device 1 that is less likely to malfunction.

[0052] The above embodiment is merely an example, and various modifications are possible. For example, the microlens array 110 and the glass substrate 120 may be rectangular in plan view. Furthermore, the planar sizes of the microlens array 110 and the glass substrate 120 may be different. In this case, it is sufficient that at least the end 131 of the adhesive layer 130 protrudes beyond the microlens array 110 in plan view. Furthermore, the positions of the tips C1 and C2 may be determined based on the bisector of a corner of the shape of the microlens array 110 in plan view.

[0053] Furthermore, the tips C1 and C2 of the protruding portions 1311 and 1312 do not have to be acute-angled, and the tips C1 and C2 may be rounded.

[0054] Although the adhesive layer 130 has two extensions 1313 and 1314 in the above example, it may have only one of them. Also, the adhesive layer 130 may have protruding portions at three or more of its four corners.

[0055] The protruding portions 1311 and 1312 may have different shapes, sizes, or orientations. For example, the distances from the corners of the microlens array 110 to the tips C1 and C2 of the protruding portions 1311 and 1312 may be different. Also, the side connected to only one of the tips C1 and C2 may have a curved portion.

[0056] In the above description, the end 131 is joined to the housing 16 via the joining material 17, but it may be joined to a portion other than the housing 16. This is sufficient as long as it reduces the risk of failure due to the diffusion plate 10 peeling off from the joining portion.

[0057] In the above embodiment, the light-emitting device 1 is described as a part of the sensor module 100, but this is not limiting. The light-emitting device 1 may be traded and used separately from the light-receiving device 2. Furthermore, the diffusion plate 10 may be traded and used separately from the light-emitting device 1.

[0058] Furthermore, the size, number of lenses, refractive index, etc. of the microlens array 110 may be changed as appropriate. The specific details of the structure, configuration, materials, size, etc. shown in the above embodiment may be changed as appropriate without departing from the spirit of this disclosure. The scope of the present invention includes the scope of the invention described in the claims and their equivalents.

[0059] The present disclosure can be used for a diffuser plate, a light emitting device, and a sensor module.

[0060] REFERENCE SIGNS LIST 1 Light-emitting device 10 Diffuser 11 Convex lens 110 Microlens array 120 Glass substrate 130 Adhesive layer 131 End 1311, 1312 Protruding portion 1313, 1314 Extension portion 15 Light-emitting element 16 Housing 17 Bonding material 2 Light-receiving device 21 Substrate 22 Light-receiving element 23 Optical member 24 Support portion 3 Module substrate 100 Sensor module C1, C2, P Tip

Claims

1. A diffuser plate comprising: a microlens array having a plurality of convex lenses arranged in an array; and a substrate bonded to the microlens array via an adhesive layer, the adhesive layer having an end located outside the outer edge of the microlens array in a planar view.

2. The diffusion plate according to claim 1, wherein the end of the adhesive layer is located outside the outer edge of the substrate in a plan view.

3. The diffusion plate according to claim 1 or 2, wherein the end of the adhesive layer has a surface that is inclined obliquely with respect to a first direction along the stacking direction of the substrate and the microlens array.

4. A diffuser plate described in any one of claims 1 to 3, wherein at least a portion of the tip of the end of the adhesive layer is located away from the midpoint of the adhesive layer in a first direction along the stacking direction of the substrate and the microlens array.

5. A diffuser plate according to any one of claims 1 to 4, wherein the end of the adhesive layer includes a curved portion when viewed in a cross section including a first direction along the stacking direction of the substrate and the microlens array.

6. A diffuser plate according to any one of claims 1 to 5, wherein the end of the adhesive layer has a portion that is asymmetrically shaped with respect to a midpoint of the adhesive layer in a first direction when viewed in a cross section including a first direction along the stacking direction of the substrate and the microlens array.

7. A diffusion plate according to any one of claims 1 to 6, wherein the end of the adhesive layer is in contact with a side surface of the substrate.

8. A diffuser plate according to any one of claims 1 to 6, wherein the end of the adhesive layer is in contact with a side surface of the microlens array.

9. A diffuser plate according to any one of claims 1 to 6, wherein the end of the adhesive layer contacts a side surface of the substrate and a side surface of the microlens array.

10. A diffuser plate according to any one of claims 1 to 9, wherein the microlens array and the substrate are rectangular in a planar view, and the adhesive layer has a protruding portion protruding from a corner of a rectangular reference range that is larger than the rectangular range of the microlens array in a planar view.

11. The diffusion plate according to claim 10, wherein the tips of said protruding portions are acute-angled.

12. The diffusion plate according to claim 10 or 11, wherein the tip of the protruding portion is off the extension line of the bisector of the angle at which the protruding portion of the microlens array protrudes in a plan view.

13. The diffusion plate according to any one of claims 10 to 12, wherein the adhesive layer has a pair of protruding portions protruding from two adjacent corners in the reference range.

14. The diffuser plate according to claim 13, wherein the tips of the set of protruding portions are located in the same area among four areas outside the reference range defined by extending the bisectors of the four corners of the microlens array in a planar view.

15. The diffuser plate according to claim 14, wherein the adhesive layer extends outside the reference range at two corners different from the two corners.

16. A diffuser plate as described in claim 13, wherein the tips of the set of protruding portions are respectively located in four regions outside the reference range defined by extending the bisectors of the four corners of the microlens array in a planar view, the four regions being symmetrical with respect to the reference range.

17. The diffuser plate according to claim 16, wherein the adhesive layer extends outside the reference range at two corners different from the two corners.

18. The diffusion plate according to any one of claims 13 to 17, wherein the edge of the protruding portion includes a curved portion in a plan view.

19. A light-emitting device comprising: a diffusion plate according to any one of claims 1 to 18; a light-emitting element that emits light to be incident on said diffusion plate; and a housing that is joined to said diffusion plate and seals said light-emitting element therein.

20. A sensor module comprising: a light emitting device according to claim 19; and a light receiving device for detecting incident light.

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