Microlens array, light-emitting device and sensor module

Abstract

This microlens array comprises: a plurality of first lenses each having a pick height no less than a first pick height; and a second lens having a pick height lower than the first pick height. In addition, the microlens array includes: a first region in which the inter-pick distance of two first lenses, arranged side by side in a first direction, among the plurality of first lenses is less than a threshold value when viewed in a plan view; and a second region in which the inter-pick distance of two first lenses, arranged side by side in the first direction, among the plurality of first lenses is greater than the threshold value when viewed in a plan view, wherein the second lens is positioned between the two first lenses in the second region.

Description

[Technical Field]

[0001] The present disclosure relates to a microlens array, a light emitting device, and a sensor module. [Background technology]

[0002] Japanese Patent Application Laid-Open No. 2003-4907 describes a microlens array in which a plurality of lenses are positioned so that the vertex intervals of the lenses are irregular. Summary of the Invention [Means for solving the problem]

[0003] The microlens array of the present disclosure comprises: a plurality of first lenses having a vertex height equal to or greater than a first vertex height; a second lens having a vertex height less than the first vertex height; Equipped with each of the plurality of first lenses and the second lens is a lens having a convex curved surface; In a light transmitting region, the entire outer periphery of the convex curved surface in a plan view is in contact with the convex curved surface of another adjacent first lens or the adjacent second lens, a first region in which the vertex distance between two first lenses arranged along a first direction among the plurality of first lenses in a plan view is smaller than a threshold; a second region in which the vertex distance between two first lenses arranged along the first direction among the plurality of first lenses in a plan view is wider than the threshold value; Including, The second lens is located between the two first lenses in the second region. death, In the transmission region, the entire outer periphery of one of the second lenses in a plan view is in contact with the plurality of first lenses. do.

[0004] The light emitting device of the present disclosure comprises: A light-emitting element; the microlens array located on a path of light emitted by the light-emitting element; Equipped with.

[0005] The sensor module of the present disclosure includes: The light-emitting device described above; a light receiving device capable of receiving light emitted from the light emitting device; Equipped with. [Brief explanation of the drawings]

[0006] [Figure 1A] 1 is a vertical cross-sectional view showing a microlens array according to an embodiment of the present invention. [Figure 1B] FIG. 1 is a plan view showing a microlens array according to an embodiment of the present invention. [Figure 2] 4 is a diagram illustrating an area where a second lens is located in the microlens array of the first embodiment. FIG. [Figure 3] 10 is a diagram illustrating the vertex height of a second lens of the microlens array according to the second embodiment. FIG. [Figure 4] FIG. 10 is a plan view showing a configuration in which the first lenses of the microlens array are provisionally arranged uniformly without changing the average value of the vertex density. [Figure 5] 10 is a diagram illustrating the vertex height of a second lens of a microlens array according to a third embodiment. FIG. [Figure 6] 10 is a diagram illustrating the vertex height of a second lens of a microlens array according to a fourth embodiment. FIG. [Figure 7] 13 is a diagram illustrating the vertex height of a second lens of a microlens array according to a fifth embodiment. FIG. [Figure 8] 13 is a diagram illustrating a second lens of a microlens array according to a sixth embodiment. FIG. [Figure 9] FIG. 20 is a diagram showing the light distribution characteristics of the first lens and the second lens in the sixth embodiment. [Figure 10] 13 is a diagram illustrating the lens arrangement in a direction along the plane of the microlens array of the seventh embodiment. FIG. [Figure 11] 13 is a diagram illustrating the lens arrangement in a direction along the plane of the microlens array of the eighth embodiment. FIG. [Figure 12]1A to 1C are diagrams illustrating an example of a method for manufacturing a microlens array according to an embodiment. [Figure 13] 1A and 1B illustrate a light emitting device and sensor module according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings.

[0008] (Embodiment 1) Fig. 1A is a longitudinal sectional view showing a microlens array according to an embodiment of the present invention, Fig. 1B is a plan view showing the microlens array, Fig. 1A shows a cross section taken along line AA in Fig. 1B.

[0009] As shown in FIGS. 1A and 1B, the microlens array 1A of embodiment 1 has a plurality of lenses 10. Each lens 10 may be a convex lens having an apex on one side. The plurality of lenses 10 may be arranged in a two-dimensional direction along an arbitrary surface S1 (a plane in FIG. 1A) and have an optical axis (i.e., a principal axis) in the normal direction of the surface S1. The plurality of lenses 10 may be connected on the surface S1 side. The plurality of lenses 10 may be integrated and may be a one-piece molded product. The microlens array 1A may include a transparent substrate 2 such as a glass substrate, and the plurality of lenses 10 may be located on the transparent substrate 2.

[0010] According to this configuration, by irradiating light from one side of the microlens array 1A (specifically, the vertex side of the multiple lenses 10 in the Z direction), the light is refracted by the multiple lenses 10, and diffused light can be emitted from the other side of the microlens array 1A.

[0011] <Details of multiple lenses> FIG. 2 is a diagram illustrating the area where the second lenses are located in the microlens array of the first embodiment.

[0012] Hereinafter, the height from a certain reference plane to the apex of a lens is referred to as the "apex height." The reference plane may be any one surface along the surface S1 on which multiple lenses 10 are arranged. Furthermore, for each lens 10, the area where the lens curved surface (e.g., a convex curved surface) is continuous is considered to be one lens 10. That is, the periphery where the lens curved surface is discontinuous, such as a valley where it intersects with another adjacent lens 10, refers to the boundary of a single lens 10. Alternatively, the bend where the lens curved surface intersects with a surface other than the lens curved surface (e.g., a flat surface) refers to the boundary of a single lens 10. The above bend does not strictly refer to a curved portion, but is a concept that includes bends with small rounding. Furthermore, the length in the optical axis direction from the lowest edge of the boundary of a single lens 10 to the highest edge of that lens 10 (e.g., the apex if a apex appears) is referred to as the "vertical dimension of the lens."

[0013] The plurality of lenses 10 may include a plurality of first lenses 11 having an apex height equal to or greater than a first apex height H1 (see FIG. 2) and one or more second lenses 12 having an apex height less than the first apex height H1 (see FIGS. 1A and 1B).

[0014] The first lens 11 and the second lens 12 may have a difference in vertex height that makes them easily distinguishable. That is, the maximum vertical dimension of one or more second lenses 12 may be half or less of the minimum vertical dimension of the multiple first lenses 11. The multiple first lenses 11 may also have variations in vertex height.

[0015] Alternatively, the plurality of first lenses 11 may have a first vertex height H1 as shown in FIG. 2. That is, the vertex heights of the first lenses 11 may be the same as the first vertex height H1. "Identical" does not necessarily mean exact agreement, but is a concept that includes cases where variations are within a predetermined error. The error range here may be from the first vertex height H1 to the first vertex height H1 + 15% of the reference vertical dimension (described below) of the first lens 11. With this configuration, first lenses 11 having the same vertex height are positioned in the plurality of regions of the microlens array 1A, and similar light distribution characteristics can be obtained by the first lenses 11 in the plurality of regions.

[0016] The multiple first lenses 11 may have the same size and lens shape. This configuration makes it easier to obtain similar light distribution characteristics in multiple regions of the microlens array 1A. Here, the concept of having the same size and lens shape does not mean only exact agreement, but also includes cases where variations are within a predetermined error. The error means that the maximum difference in sag at each point compared to a single lens curved surface is within 15% of the reference vertical dimension (described below) of the first lens 11. Furthermore, even if the boundary positions of the lens curved surfaces are different, the curved surface shapes may be considered to be the same as long as the shapes within the boundaries are the same.

[0017] 1B, the microlens array 1A may include, in a plan view, a first region R1 in which the vertex spacing Lp of two first lenses 11 aligned along a first direction (e.g., the Y direction) is narrower than a threshold value THp, and a second region R2 in which the vertex spacing Lp is wider than the threshold value THp. This configuration causes variations in the vertex spacing of the first lenses 11. This reduces the effect of light passing through multiple first lenses 11 regularly overlapping and generating interference fringes, thereby achieving good light distribution characteristics. A plan view refers to a view from a direction perpendicular to the surface S1.

[0018] 1B, the microlens array 1A may have a third region R3 in which the vertex spacing of two first lenses 11 aligned along a second direction (e.g., the X direction) different from the first direction is narrower than a threshold value THp when viewed in a plan view, and a fourth region R4 in which the vertex spacing is wider than the threshold value THp. This configuration also causes variations in the vertex spacing of the first lenses 11. This reduces the effect of light passing through multiple first lenses 11 regularly overlapping and generating interference fringes, thereby achieving good light distribution characteristics.

[0019] The second lens 12 may be located between two first lenses 11 in a second region R2 where the vertex spacing is greater than the threshold value THp. The second lens 12 may be located between multiple first lenses 11 in a region where the second region R2 where the vertex spacing is greater than the threshold value THp and the fourth region R4 overlap.

[0020] As shown in FIG. 2, the threshold value THp may be set so that the depth of the valley between two adjacent first lenses 11 is equal to or less than the vertex spacing corresponding to the depth Hx at which the difficult-to-shape portion D1 of the lens curved surface appears. The vertex spacing corresponding to the depth Hx means that the valley reaches the depth Hx at that vertex spacing. This setting can achieve good light distribution characteristics. This is because, if there were no second lenses 12 in a location where the distance between adjacent first lenses 11 is large, such as the second region R2 or the fourth region R4, the valleys in that location would be deep. Therefore, the number of valleys that make it difficult to shape the lens curved surface increases. On the other hand, by positioning the second lenses 12 between multiple first lenses 11 in the second region R2 or the fourth region R4, the number of deep valleys that make it difficult to shape the lens curved surface can be reduced. Therefore, the desired lens curved surface can be easily obtained, and good light distribution characteristics of the microlens array 1A can be achieved.

[0021] Alternatively, as shown in FIG. 2, the threshold value THp may be set to a value equal to or less than the apex spacing corresponding to the depth Hy at which the valley depth between two adjacent first lenses 11 causes an unrequired base D2 of the first lenses 11 to appear. The apex spacing corresponding to the depth Hy means that the valley reaches the depth Hy at that apex spacing. The lens shape of the first lenses 11 is designed to produce required light distribution characteristics, but this lens shape corresponds to a shape within a certain width of the first lenses 11. If light passes through a base D2 wider than that width, the light may deviate from the required light distribution characteristics. Therefore, the above setting reduces the number of first lenses 11 at which base D2 appears, thereby achieving good light distribution characteristics.

[0022] Furthermore, the above configuration has the advantage of easily realizing a light distribution characteristic with a wide diffusion direction. If there were no second lens 12, the aspect ratio (i.e., length / width) of first lens 11 would be limited in order to eliminate deep valleys that would be difficult to form in the lens curved surface. However, the presence of second lens 12 alleviates the limitation on the aspect ratio of first lens 11, allowing the aspect ratio of first lens 11 to be increased. Therefore, it is easy to realize a light distribution characteristic with a wide diffusion direction.

[0023] As described above, the second lens 12 may have an apex height that is lower than the apex height of the first lens 11. With this configuration, the area ratio occupied by the second lens 12 can be made smaller than the area ratio occupied by the first lens 11 in the microlens array 1A. Therefore, the proportion of the light diffusion effect caused by the second lens 12 in the light diffusion effect of the microlens array 1A is smaller than the proportion of the light diffusion effect caused by the multiple first lenses 11. Therefore, the second lens 12 can reduce the deviation of the light distribution characteristics of the microlens array 1A from the desired characteristics.

[0024] The second lens 12 may be positioned so that a vertex appears between the plurality of first lenses 11, or so that a lens curved surface that does not include a vertex appears between the plurality of first lenses 11.

[0025] When a transmissive region Rc (see FIG. 13) is set in the microlens array 1A, the entire outer periphery of each lens 10 may be in contact with another adjacent lens 10 at least in the transmissive region Rc. The transmissive region Rc may be defined as an area that transmits light, for example, in specifications. With this configuration, no surface other than the curved surface of the lens (for example, a flat surface) is located at the boundary between the lenses 10 in the transmissive region Rc, thereby achieving better light distribution characteristics.

[0026] In the microlens array 1A of the first embodiment, the plurality of lenses 10 may include a third lens (for example, a convex lens) in addition to the first lens 11 and the second lens 12. The second lenses 12 do not have to be located in all of the second region R2 and the fourth region R4 where the vertex spacing is wide, and the effect of the second lenses 12 increases as the proportion of the second lenses 12 located in the second region R2 and the fourth region R4 where the vertex spacing is wide.

[0027] (Embodiment 2) Fig. 3 is a diagram illustrating the vertex height of the second lenses of the microlens array of embodiment 2. The microlens array 1B of embodiment 2 differs from embodiment 1 in the vertex height of the second lenses 12, but the other components are similar to embodiment 1. Detailed description of similar components will be omitted. Fig. 4 is a plan view showing a configuration in which the first lenses of the microlens array are hypothetically uniformly arranged without changing the average vertex density.

[0028] Here, a case where the plurality of first lenses 11 (see FIG. 1B) are uniformly arranged without changing the average vertex density will be described. In FIGS. 3 and 4, the first lenses 11 before and after the uniform arrangement are indicated by different reference numerals. The uniform arrangement means that the vertices of the plurality of first lenses 11 are uniformly arranged in a plan view. In the uniform arrangement, the vertices of the plurality of first lenses 11 may have the same height. The uniform arrangement means an arrangement in which the plurality of first lenses 11 are arranged in a lattice pattern, as shown in FIG. 4. Alternatively, the uniform arrangement may be an arrangement in which the plurality of first lenses 11 are arranged in a hexagonal lattice pattern. The hexagonal lattice arrangement means an arrangement in which a plurality of regular hexagons are closely spaced (i.e., an arrangement in which each side of a regular hexagon forms the boundary between a pair of adjacent first lenses 11). The curved surface of each of the plurality of uniformly arranged first lenses 11v continues up to the boundary line B (see FIG. 4) between the adjacent first lenses 11v. Before the uniform arrangement (see FIG. 1B), the boundaries of the multiple first lenses 11 vary in height and low points, resulting in different hem lengths. Therefore, when the lenses are virtually uniformly arranged, a portion of the hem of a first lens 11 that was visible before the uniform arrangement may be hidden, or a portion of the hem of a first lens 11 that was not visible before the uniform arrangement may be visible. The newly visible hem portion can be reconstructed by assuming that the lens surface has a similar shape to the other first lenses 11 that were visible in large areas before the uniform arrangement. FIG. 4 shows the vertex P0, boundary line B, the highest point P1 of boundary line B, and the lowest point P2 of boundary line B for only one first lens 11v among the multiple first lenses 11v that are virtually uniformly arranged. FIG. 3 illustrates an example in which the first lenses 11v indicated by the two-dot chain lines are virtually uniformly arranged.

[0029] 3, the second lens 12 of the second embodiment may have a vertex height equal to or less than the first boundary height HB1. The first boundary height HB1 means the height of the lowest point P1 (see FIG. 4) of the boundary between a pair of adjacent first lenses 11, assuming that multiple first lenses 11 are evenly arranged without changing the average vertex density.

[0030] According to this configuration, when the microlens array 1B is viewed in plan, the area ratio of the one or more second lenses 12 is significantly smaller than the area ratio of the multiple first lenses 11. Therefore, of the light diffusion effect of the microlens array 1A, the ratio of the diffusion effect caused by the second lens 12 is significantly smaller than the ratio of the diffusion effect caused by the multiple first lenses 11. Therefore, the second lens 12 can reduce the change in the light distribution characteristics of the microlens array 1B from the required characteristics.

[0031] The vertex heights of the multiple second lenses 12 do not have to be the same. The vertex height of the second lenses 12 may be lower than the first boundary height HB1 and higher than the height Hx at which it becomes difficult to form a curved lens surface.

[0032] (Embodiment 3) 5 is a diagram illustrating the vertex height of the second lenses of the microlens array of embodiment 3. The microlens array 1C of embodiment 3 differs from embodiment 1 in the vertex height of the second lenses 12, but the other components are similar to embodiment 1. Detailed description of the similar components will be omitted.

[0033] The vertex height H2 of the second lens 12 according to the third embodiment satisfies the following condition. HB1-ΔH1v×50% ≦ H2 ≦ HB1 Here, HB1 is the first boundary height described in embodiment 2. ΔH1v is the "reference vertical dimension" of the first lens 11, and means the vertical dimension of the first lens 11v when multiple first lenses 11 are virtually uniformly arranged without changing the average value of the vertex density.

[0034] This configuration achieves the following effect in addition to the same effect as in the second embodiment. That is, the vertical dimension of the first lens 11 adjacent to the second lens 12 becomes close to the vertical dimension ΔH1v of the virtual first lens 11v. Therefore, the proportion of the lens surface j1 (i.e., the lens surface j1 with a steep slope) near the base that is not included in the virtual first lens 11v can be reduced. The lens curve of the virtual first lens 11v is sometimes designed to achieve a desired light distribution characteristic, and the lens surface j1 with a steep slope located nearer the base than the virtual first lens 11v can deviate from the desired light distribution characteristic. In such cases, the microlens array 1C of the third embodiment reduces the proportion of the lens surface j1, thereby achieving a favorable light distribution characteristic.

[0035] (Embodiment 4) 6 is a diagram illustrating the vertex height of the second lenses of the microlens array of embodiment 4. The microlens array 1D of embodiment 4 differs from embodiment 1 in the vertex height of the second lenses 12, but the other components are similar to embodiment 1. Detailed description of the similar components will be omitted.

[0036] In the fourth embodiment, the second lens 12 may have a vertex height equal to or less than the second boundary height HB2. The second boundary height HB2 refers to the height of the highest point P2 of the boundary between a pair of adjacent first lenses 11v, assuming that multiple first lenses 11 are evenly arranged without changing the average vertex density.

[0037] According to this configuration, when the microlens array 1D is viewed in a plan view, the area ratio of the one or more second lenses 12 is extremely small compared to the area ratio of the multiple first lenses 11. Therefore, of the light diffusion effect of the microlens array 1A, the ratio of the diffusion effect caused by the second lens 12 is significantly smaller than the ratio of the diffusion effect caused by the multiple first lenses 11. Therefore, the second lens 12 can reduce the change in the light distribution characteristics of the microlens array 1D from the required characteristics.

[0038] The vertex heights of the multiple second lenses 12 do not have to be the same. The vertex height of the second lenses 12 may be lower than the second boundary height HB2 and higher than the height Hx at which it becomes difficult to form a curved lens surface.

[0039] (Embodiment 5) 7 is a diagram illustrating the vertex height of the second lenses of the microlens array of embodiment 5. The microlens array 1E of embodiment 5 differs from embodiment 1 in the vertex height of the second lenses 12, but the other components are similar to embodiment 1. Detailed description of the similar components will be omitted.

[0040] The vertex height H2 of the second lens 12 according to the fifth embodiment satisfies the following condition. HB2-ΔH1v×50% ≦ H2 ≦ HB2 Here, HB2 is the second boundary height HB2 described in the fourth embodiment. ΔH1v is the “reference vertical dimension” of the first lens 11 described in the third embodiment.

[0041] This configuration achieves the following effect in addition to the same effect as in the fourth embodiment. That is, the vertical dimension of the first lens 11 adjacent to the second lens 12 becomes close to the vertical dimension ΔH1v of the virtual first lens 11v. Therefore, the proportion of the lens surface j1 (i.e., the lens surface j1 with a steep slope) near the base that is not included in the virtual first lens 11v can be reduced. The lens curve of the virtual first lens 11v is sometimes designed to achieve a desired light distribution characteristic, and the lens surface j1 with a steep slope located nearer the base than the virtual first lens 11v can deviate from the desired light distribution characteristic. In such cases, the microlens array 1E of the fifth embodiment reduces the proportion of the lens surface j1, thereby achieving a favorable light distribution characteristic.

[0042] (Embodiment 6) Fig. 8 is a diagram illustrating a second lens of a microlens array according to embodiment 6. Fig. 9 is a diagram illustrating the light distribution characteristics of a first lens and a second lens according to embodiment 6. A microlens array 1F according to embodiment 6 differs from embodiment 3 or embodiment 5 in the lens shape and size of the second lens 12, but the other components are similar to embodiment 3 or embodiment 5. Detailed description of similar components will be omitted.

[0043] The second lens 12 has the apex height described in the third or fifth embodiment.

[0044] The lens shape of the second lens 12 in the sixth embodiment may be similar to the lens shape of the first lens 11. According to this configuration, the light distribution characteristics of the light that has passed through the second lens 12 are close to the light distribution characteristics of the light that has passed through the first lens 11. Therefore, while the required light distribution characteristics are realized by the multiple first lenses 11, it is also possible to obtain characteristics close to the required light distribution characteristics for the light that has passed through the second lens 12. Therefore, it is possible to realize good light distribution characteristics.

[0045] Furthermore, the reference width W2v of the second lens 12 may be twice the average value of the deviation amount ΔP of the vertex position of the first lens 11 ±30%.

[0046] Here, the reference width W2v of the second lens 12 means the length of a portion of the second lens 12 that has a shape similar to that of the first lens 11, which corresponds to the reference width W1v of the first lens 11. In other words, the reference width W2v of the second lens 12 corresponds to the reference width W1v of the first lens 11 × the similarity ratio between the first lens 11 and the second lens 12.

[0047] The reference width W1v of the first lens 11 means the widest width of the boundary line B (see Figure 4) of one evenly arranged first lens 11v when multiple first lenses 11 are evenly arranged without changing the average value of the vertex density.

[0048] Furthermore, the deviation amount ΔP of the vertex position of the first lenses 11 means the distance between the vertex position of the evenly arranged first lenses 11v and the vertex position of the first lenses 11 before the evenly arranged arrangement. However, the deviation amount ΔP is calculated when the evenly arranged first lenses 11v and the evenly arranged first lenses 11 are stacked so that the total deviation amount ΔP is smallest. Although the deviation amount ΔP is drawn to indicate a displacement in the Y direction in FIG. 8, it actually means the distance between two points on the XY plane, including displacement in the X direction.

[0049] Furthermore, the average value of the amount of deviation ΔP may refer to the average value for all first lenses 11 included in the microlens array 1F, or, if a transmission region Rc (see FIG. 13) is defined, may refer to the average value for all first lenses 11 included in the transmission region Rc. Furthermore, A±B% means that it is within the range of A×(100−B)% to A×(100+B)%.

[0050] The above configuration provides the following effect. Specifically, when the plurality of first lenses 11 are dispersed rather than uniformly arranged to reduce the occurrence of interference fringes, the distance between the vertices of two adjacent first lenses 11 also becomes dispersed. Furthermore, when the above dispersion is applied, the most common value for the amount of misalignment of the vertex positions of the first lenses 11 is close to the average value of the amount of misalignment. Therefore, in a region where the distance between the vertices of two adjacent first lenses 11 is wider than when they are uniformly arranged, the most common value for the distance between the vertices is close to twice the average value of the amount of misalignment.

[0051] When a second lens 12 is located between two first lenses 11 having an apex distance that is twice the average amount of misalignment, if the reference width W2v of the second lens 12 is close to twice the average amount of misalignment, the apex side of the second lens 12 will be exposed to the outside world from a height close to the reference width W2v, as shown in Fig. 8. In other words, by setting the reference width W2v of the second lens 12 to the above length, there will be more second lenses 12 whose apex side is exposed to the outside world from a height close to the reference width W2v.

[0052] As shown in FIG. 9, the light distribution characteristics of first lens 11, the apex side of which is exposed to the outside world from reference width W1v, and second lens 12, the apex side of which is exposed to the outside world from reference width W2v, are similar because they have similar lens shapes.

[0053] Therefore, according to the microlens array 1F of the sixth embodiment, it is possible to obtain light distribution characteristics similar to those of the first lenses 11 in many of the second lenses 12, thereby realizing good light distribution characteristics.

[0054] (Embodiment 7) FIG. 10 is a diagram illustrating the lens arrangement in a direction along the plane of the microlens array of embodiment 7. In FIG. 10, the first lens 11 is represented by a dashed circle, and the second lens 12 is represented by a thick dashed circle. The dashed circle represents the outer periphery of the first lens 11 at approximately the middle height. The thick dashed circle represents the outer periphery of the second lens 12 at approximately the middle height. The outer periphery of the second lens 12 shown in the thick dashed circle may not be exposed to the outside because it overlaps with the first lens 11. In FIG. 10, the two-dot chain circle represents a virtual lens surface that does not appear as a lens surface, and is referred to as a virtual second lens 12v. The center point of each circle represents the vertex of the lens.

[0055] In the microlens array 1G of the seventh embodiment, the first lenses 11 may be positioned non-uniformly in a plan view, while the second lenses 12 may be positioned regularly in a plan view.

[0056] Regularly positioned means that a single grid is defined in which the multiple second lenses 12 are positioned in the squares of the grid. In the example of Fig. 10, a single grid can be defined in which the multiple second lenses 12 and the multiple virtual second lenses 12v are surrounded by squares. The grid may be the same size as the grid obtained when the multiple first lenses 11 are rearranged so that the vertices are evenly distributed without changing the average vertex density.

[0057] This configuration has the advantage that the arrangement of the second lenses 12 can be easily designed when designing the microlens array 1G. That is, the designer first determines the arrangement of the first lenses 11 and the second lenses 12 when the multiple first lenses 11 and the multiple second lenses 12 are evenly arranged. Then, the vertex positions of the multiple first lenses 11 are shifted from the even arrangement to an uneven arrangement. As a result, the microlens array 1G of the seventh embodiment can be designed such that if the valley between two adjacent first lenses 11 is shallower than the second lenses 12, the second lenses 12 do not appear in the valley, and if the valley between two adjacent first lenses 11 is deeper than the second lenses 12, the second lenses 12 appear in the valley.

[0058] (Embodiment 8) FIG. 11 is a diagram illustrating the lens arrangement in the direction along the plane of the microlens array of the eighth embodiment.

[0059] In the microlens array 1H of embodiment 8, when viewed in a plane, the multiple first lenses 11 are positioned unevenly, while each second lens 12 may be located at the center of a polygon plg connecting the vertices of the multiple first lenses 11 located around the periphery.

[0060] The first lenses 11 around the second lens 12 may mean the multiple first lenses 11 in contact with the second lens 12, or may mean the n first lenses 11 closest to the second lens 12. The number n may be four if the multiple first lenses 11 are arranged in a manner similar to a square lattice, or may be six if the multiple first lenses 11 are arranged in a manner similar to a hexagonal lattice.

[0061] The center of the polygon plg may refer to the center of gravity of the polygon plg. The center of gravity refers to the center of gravity when the polygon plg is assumed to be a surface with a constant weight density, and refers to the sum of position vectors from an arbitrary reference point to all vertices of the polygon plg / the number of vertices.

[0062] Alternatively, the center of the polygon plg may be the point where the difference in distance to each vertex of the polygon plg is smallest, or may be the midpoint of the longest diagonal of the polygon plg.

[0063] Furthermore, the center of the polygon plg is not limited to a point that exactly coincides with each of the above points, but may be a point located within a range in which an error equivalent to a tolerance has been added to each of the above points.

[0064] According to this configuration, it is possible to increase the proportion of second lenses 12 in which vertices appear among the plurality of second lenses, thereby reducing the bias in the light distribution of light transmitted through the plurality of second lenses 12 and achieving better light distribution characteristics for the microlens array 1H.

[0065] <Manufacturing method> 12 is a diagram illustrating an example of a manufacturing method for a microlens array according to an embodiment. Next, a manufacturing process for the microlens array 1A according to embodiment 1 will be described. The same manufacturing process can also be applied to the microlens arrays 1B to 1H according to embodiments 2 to 8.

[0066] The manufacturing process of the microlens array 1A includes a master mold fabrication process (J1 to J4) for fabricating a master mold, an electroforming mold fabrication process (J5 to J7) for fabricating an electroforming mold, a secondary mold fabrication process (J8, J9) for fabricating a secondary mold, and an imprinting process (J10 to J12) for molding a resin on a glass substrate.

[0067] In the master mold fabrication process, resist resin 81 is applied to a transfer substrate 80 (step J1), and pretreatment (e.g., baking) is performed (step J2). After that, the resist resin 81 is exposed to grayscale light using laser lithography (step J3). A development process is then performed after the exposure (step J4), thereby fabricating a master mold 82. The cavities in the master mold 82 have the shape of the lens portions of the microlens array 1A. In step J3, the portions of the resist resin 81 from which the resist resin 81 is to be removed are exposed, but there is a limit (e.g., 15 μm to 50 μm) to the depth of the resist resin 81 that can be exposed. Therefore, if the valleys between the first lenses 11 are deep enough to exceed the limit, the depth of the resist resin 81 at the portions corresponding to the vertices of the first lenses 11 also exceeds the limit. This makes it difficult to expose the vertices of the first lenses 11 in the resist resin 81. However, in the microlens array 1A, the presence of the second lenses 12 means that there are no or few valleys whose depth exceeds the limit, so that it is easy to fabricate a master mold 82 of the required shape.

[0068] In the electroforming mold production process, a conductive film 83 is formed on the surface of the master mold 82 by sputtering or the like (step J5), a conductor 84 made of Ni (nickel) or the like is formed by transferring the master mold 82 by electroplating (step J6), and the conductor 84 is then released and polished (step J7) to produce the electroforming mold 85.

[0069] In the secondary mold manufacturing process, a thermoplastic resin film 86 is thermally imprinted using an electroforming mold 85 (step J8), and the resin film 86 is peeled off from the electroforming mold 85 (step J9) to produce a secondary mold 87 made of a resin material.

[0070] In the imprinting process, for example, an ultraviolet-curable transparent resin 89 is applied to a glass substrate 88 (step J10), a secondary mold 87 is applied to the transparent resin 89 on the glass substrate 88, and the transparent resin 89 is cured by ultraviolet irradiation or the like (step J11). The cured transparent resin 89 is then released (step J12) to obtain an intermediate product 90 of the microlens array 1A. Thereafter, the intermediate product 90 is subjected to characteristic evaluation, dicing, appearance inspection, etc., to obtain the microlens array 1A.

[0071] <Light-emitting devices and sensor modules> FIG. 13 is a diagram illustrating a light-emitting device and a sensor module according to an embodiment of the present disclosure. A light-emitting device 50 according to this embodiment includes a light-emitting element 51 and the microlens array 1A according to embodiment 1, which is located on the path of light emitted by the light-emitting element 51. The microlens array 1A may be replaced with the microlens arrays 1B to 1H according to embodiments 2 to 8. The lens surfaces of the microlens array 1A (i.e., the vertices of the first lens 11 and the second lens 12) may face the light-emitting element 51. The light-emitting element 51 outputs laser light, but may also be configured to emit non-laser light. The light-emitting element 51 may be housed in a package 52 having a cavity structure, and the microlens array 1A may be bonded to the package 52. The microlens array 1A may also serve as a lid for the package 52.

[0072] The light emitting device 50 includes the microlens array 1A of the embodiment, and can output good diffused light with few interference fringes. Furthermore, the light emitting device 50 can be configured to output good diffused light that spreads over a wide angle.

[0073] As shown in FIG. 13 , the sensor module 100 of this embodiment includes a light-emitting device 50 that outputs diffused light and a light-receiving device 60 that can receive the light emitted by the light-emitting device 50. The light-receiving device 60 may receive the light emitted by the light-emitting device 50 directly or by receiving light reflected from the light-emitting device 50. The sensor module 100 may be configured to perform any type of detection, such as LiDAR (light detection and ranging) or a photoelectric sensor that detects whether or not an object is present on the light path. The light-emitting device 50 and the light-receiving device 60 may be mounted on a single module substrate 70 or on separate module substrates.

[0074] The light-receiving device 60 includes a light-receiving element 61 such as a photodiode. The light-receiving device 60 may include a lens 62 that focuses incident light onto the light-receiving element 61, and a filter element 63 that narrows the wavelength of the incident light. The light-receiving element 61 may be housed in a package 64, and the lens 62 and the filter element 63 may be supported by the package 64.

[0075] The sensor module 100 of this embodiment includes the microlens array 1A of this embodiment, and thus is capable of sensing using good diffused light. Furthermore, wide-angle sensing using good diffused light is also possible.

[0076] The light-emitting device 50 of this embodiment may be configured to output diffused light for purposes other than sensing.

[0077] The above describes the embodiments of the present disclosure. However, the microlens array, light-emitting device, and sensor module of the present disclosure are not limited to the above embodiments. For example, in the above embodiments, the microlens array according to the embodiment was described with reference to drawings in which the vertex height, size, and lens shape of the multiple first lenses 11 are identical to one another. However, the multiple first lenses 11 may have variations in vertex height, size, and lens shape. Furthermore, in the above embodiments, microlenses having the first lens 11 and the second lens 12 are shown as the multiple lenses 10. However, the multiple lenses 10 may include a third lens separate from the first lens 11 and the second lens 12. Other details described in the embodiments may be modified as appropriate without departing from the spirit of the invention. [Industrial Applicability]

[0078] The present disclosure can be used in microlens arrays, light emitting devices, and sensor modules. [Explanation of symbols]

[0079] 1A~1H Microlens Array 10 Lenses 11 First lens 11v Evenly spaced first lens 12 Second lens Lp vertex spacing THp threshold R1 1st area R2 2nd area R3 3rd area R4 4th area H1 First vertex height HB1 First boundary height HB2 Second boundary height ΔH1v Reference vertical dimension W1v, W2v standard width ΔP deviation amount plg polygon 50 Light-emitting devices 51 Light-emitting element 60 Light receiving device 61 Photodetector 100 Sensor Module

Claims

1. a plurality of first lenses having a vertex height equal to or greater than a first vertex height; a second lens having a vertex height less than the first vertex height; Equipped with each of the plurality of first lenses and the second lens is a lens having a convex curved surface, In a light transmitting region, the entire outer periphery of the convex curved surface in a plan view is in contact with the convex curved surface of another adjacent first lens or the adjacent second lens, a first region in which a distance between vertices of two first lenses arranged along a first direction among the plurality of first lenses in a plan view is smaller than a threshold; a second region in which a distance between vertices of two first lenses arranged along the first direction among the plurality of first lenses in a plan view is wider than the threshold; Including, the second lens is located between the two first lenses in the second region; In the transmission region, the entire outer periphery of one of the second lenses in a plan view is in contact with the plurality of first lenses. Microlens array.

2. a third region in which, in a plan view, a distance between vertices of two first lenses arranged along a second direction different from the first direction among the plurality of first lenses is smaller than the threshold value; a fourth region in which a distance between vertices of two first lenses arranged along the second direction among the plurality of first lenses in a plan view is wider than the threshold; Including, the second lens is located between the plurality of first lenses in an area where the second area and the fourth area overlap; The microlens array of claim 1 .

3. If the plurality of first lenses are uniformly arranged without changing the average value of the vertex density, and the height of the lowest point of the boundary between a pair of adjacent first lenses is called the first boundary height, then: The apex height of the second lens is equal to or less than the first boundary height. The microlens array according to claim 1 or 2.

4. HB1-ΔH1v×50% ≦ H2 ≦HB1 where HB1 is the first boundary height, ΔH1v is the vertical dimension of the first lens when the lenses are evenly arranged, and H2 is the vertex height of the second lens.

4. The microlens array according to claim 3.

5. If the plurality of first lenses are uniformly arranged without changing the average value of the vertex density, and the height of the highest point of the boundary between a pair of adjacent first lenses is called the second boundary height, The apex height of the second lens is equal to or less than the second boundary height. The microlens array according to claim 1 or 2.

6. HB2-ΔH1v×50% ≦ H2 ≦HB2 where HB2 is the second boundary height, ΔH1v is the vertical dimension of the first lens in the case of the uniform arrangement, and H2 is the vertex height of the second lens.

6. The microlens array according to claim 5.

7. the lens shape of the second lens is similar to the lens shape of the first lens; When the plurality of first lenses are uniformly arranged without changing the average value of the vertex density, the widest width of the boundary line between one of the first lenses and the surrounding first lenses is called the reference width of the first lens, and the length of a portion of the second lens having a shape similar to that of the first lens, which corresponds to the reference width of the first lens, is called the reference width of the second lens, a reference width of the second lens is twice the average value of the deviation amounts of the first lenses from the uniform arrangement ±30%; The microlens array according to claim 1 or 2.

8. a vertex of the second lens is located at the center of a polygon connecting vertices of a plurality of first lenses located around the second lens in a plan view; The microlens array according to claim 1 or 2.

9. A light-emitting element; the microlens array according to claim 1 or 2, which is located on a path of light emitted by the light-emitting element; A light emitting device comprising:

10. A light emitting device according to claim 9; a light receiving device capable of receiving light emitted from the light emitting device; A sensor module comprising:

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