Optical element, optical module, and method for manufacturing optical module

Abstract

To provide a technique capable of suppressing light leakage from an optical module with a simpler and smaller configuration.SOLUTION: An optical element (3) has an optical region (3a) in which an optical element is disposed on a part of at least one side of a plate-like base material unit (3b). Around the optical region (3a) in a surface where the optical region (3a) of the base material unit (3b) is provided, a peripheral region (3d) is provided in which no optical function as an optical element is used. In the peripheral region (3d) or a region corresponding to the peripheral region (3d) on an opposite side of the base material unit (3b), a light shielding diffusion unit (3e) for suppressing transmission of light or diffusing light is formed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical element, an optical module having an optical element, and a method for manufacturing the same. [Background technology]

[0002] Conventionally, microlens arrays in which a plurality of lens elements are arranged have been known and are used in devices for, for example, illumination or measurement, face authentication, spatial authentication, etc. (See, for example, Patent Documents 1 and 2.) Furthermore, by unitizing this microlens array and a light source into an optical module, it has become easier to assemble and manage the above-mentioned devices using the microlens array.

[0003] On the other hand, the light sources used in these optical modules are often high-intensity light sources such as VCSEL (Vertical Cavity Surface Emitting Laser) laser light sources, which can cause eye-safety problems. In relation to these problems, an optical element is known that has a plurality of regions periodically arranged in a mosaic pattern on its surface, and each of the plurality of regions has a random spatial distribution of microstructures (see, for example, Patent Document 3, etc.).

[0004] However, the optical modules described above have a sufficiently simple and compact structure, and the leakage of high-intensity light has not been sufficiently suppressed. Also, many of the optical modules have a structure in which optical elements such as microlens arrays are fixed with adhesive, and the optical performance of the optical elements can be affected by adhesive leakage or other problems. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2005 / 103795 [Patent Document 2] International Publication No. 2015 / 182619 [Patent Document 3] Japanese Patent Publication No. 2020-173422 Summary of the Invention [Problem to be solved by the invention]

[0006] The technology disclosed herein was invented in consideration of the above circumstances, and its purpose is to provide a technology that can suppress light leakage from an optical module with a simpler and more compact configuration. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the optical element according to the present disclosure is an optical element having an optical region in which optical elements are arranged on a portion of at least one surface of a flat substrate portion, and on the surface of the substrate portion on which the optical region is provided, a peripheral region is provided around the optical region in which the optical function of the optical element is not used, and the peripheral region or the region corresponding to the peripheral region on the opposite surface of the substrate portion is configured so that light transmission is suppressed or a light-shielding diffusion portion that diffuses light is formed.

[0008] More specifically, an optical region in which optical elements are arranged on a part of at least one surface of a flat substrate portion; the optical region is provided on the surface of the base member, the optical region being provided around the optical region; a peripheral region where the optical elements are not disposed; a light-shielding / diffusing portion provided in the peripheral region and / or a region corresponding to the peripheral region on the opposite surface of the base portion, which suppresses light transmission or diffuses light; Equipped with.

[0009] Here, in the base member, the optical region may be formed on a surface that is recessed with respect to the peripheral region.

[0010] The optical element may be a lens element, and the optical region may be a lens region in which a plurality of the lens elements are arranged.

[0011] The light-shielding diffusion portion may have a film of a photoresist material formed in the peripheral region and / or in a region corresponding to the peripheral region on the opposite surface of the base portion.

[0012] The light-shielding / diffusing portion may have a roughened surface in which the surface roughness of the peripheral region and / or a region corresponding to the peripheral region on the opposite surface of the base member is greater than that of the side surface of the base member.

[0013] An optical module according to the present disclosure includes the optical element described above and a light source that causes light to be incident on the optical element; a holding member that holds the optical element and the light source; Equipped with the holding member has a base portion to which the light source is fixed and a side wall portion to which the optical element is fixed, the sidewall portion is provided with a mounting surface on which the peripheral region of the optical element is mounted, The optical module has a predetermined adhesive interposed between the peripheral area and the mounting surface.

[0014] The upper end of the sidewall portion may be formed to be at the same height as the upper surface of the optical element or lower than the upper surface of the optical element.

[0015] The predetermined adhesive may have a light-blocking property and may form the light-blocking diffusion portion.

[0016] A method for manufacturing an optical element according to the present disclosure is a method for manufacturing an optical element having an optical region in which optical elements are arranged on a part of at least one surface of a flat substrate, the method comprising: a molding process for integrally forming the flat substrate portion, the optical region, and a peripheral region disposed around the optical region and not used as the optical element for performing any optical function; a light-shielding diffusion portion forming step of forming a light-shielding diffusion portion that suppresses light transmission or diffuses light in the peripheral region and / or a region corresponding to the peripheral region on the opposite surface of the base material; It has.

[0017] The light-shielding diffusion portion forming step is performed simultaneously with the molding step, In the molding process, a roughened surface having a surface roughness greater than that of the side surface of the base material in the peripheral region and / or the region corresponding to the peripheral region on the opposite surface of the base material may be molded as the light-shielding diffusion portion.

[0018] In addition, the light-shielding diffusion portion forming process may be performed after the molding process, and may include a process of forming a film of photoresist material by photolithography on the surface of the peripheral region molded in the molding process and / or the region corresponding to the peripheral region on the opposite surface of the base portion.

[0019] In addition, the light-shielding diffusion portion forming process may be performed after the molding process, and may include a roughening process for roughening the surface of the peripheral region molded in the molding process and / or the region corresponding to the peripheral region on the opposite side of the base material.

[0020] A method for manufacturing an optical module according to the present disclosure includes: an adhesive application step of applying the predetermined adhesive to the mounting surface; and a fixing step of placing and fixing the optical element on the placement surface on which the predetermined adhesive is applied.

[0021] In the method for manufacturing an optical module, the predetermined adhesive may have a light-blocking property.

[0022] In the present disclosure, the means for solving the above problems can be used in combination as far as possible. [Effects of the Invention]

[0023] According to the present disclosure, it is possible to provide a technique that can suppress light leakage from an optical module with a simpler and more compact configuration. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a schematic diagram of an optical module. [Figure 2] FIG. 2 is an enlarged view of the vicinity of the step portion of the optical module. [Figure 3] FIG. 3 is a schematic diagram of a first modified example of the optical module. [Figure 4] FIG. 4 is a schematic diagram of second and third modified examples of the optical module. [Figure 5] FIG. 5 is a schematic diagram of a fourth modified example of the optical module. [Figure 6] FIG. 6 is a flowchart showing a method for manufacturing a microlens array. [Figure 7] FIG. 7 is a flowchart showing a method for manufacturing an optical module. [Figure 8] FIG. 8 is a schematic diagram of a distance measuring device as an example of an application of the optical module. [Figure 9] FIG. 9 is a schematic diagram of a microlens array. [Figure 10] FIG. 10 shows an example of the configuration of a conventional optical module. DETAILED DESCRIPTION OF THE INVENTION

[0025] Microlens arrays and optical modules according to embodiments of the present disclosure will be described below with reference to the drawings. Note that the configurations and combinations thereof in the embodiments are merely examples, and additions, omissions, substitutions, and other modifications of the configurations may be made as appropriate within the scope of the present disclosure. The present disclosure is not limited by the embodiments, but is limited only by the claims.

[0026] 8 shows a schematic diagram of a TOF (Time Of Flight) distance measurement device 100 as an example of an application of the microlens array and optical module according to the embodiment. The TOF distance measurement device 100 is a device that measures the distance to various parts on the surface of a measurement object O by measuring the time of flight of irradiated light, and includes a light source control unit 101, an irradiation light source 102, an irradiation optical system 103, a light receiving optical system 104 that collects reflected light from the measurement object O, a light receiving element 105, and a signal processing circuit 106.

[0027] When the irradiation light source 102 emits pulsed light based on a drive signal from the light source control unit 101, the pulsed light passes through the irradiation optical system 103 and is irradiated onto the measurement object O. The reflected light from the surface of the measurement object O passes through the light receiving optical system 104 and is received by the light receiving element 105. The light is received and converted into an appropriate electrical signal by a signal processing circuit 106. Then, a calculation unit (not shown) measures the time from when the irradiation light source 102 emits the irradiation light until the reflected light is received by the light receiving element 105, that is, the time of flight of the light, thereby measuring the distance to each location on the measurement object O.

[0028] A microlens array may be used as the irradiation optical system 103 in this TOF distance measurement device 100. FIG. 9 shows a schematic diagram of a microlens array. The left side of the figure shows a front view of the microlens array, and the right side of the figure shows a side view of the microlens array. A microlens array is an optical element having a lens region 103a in which minute lens elements 1030a with diameters of about 10 μm to several mm are arranged, for example, in the center of one side of a flat substrate portion 103b. The lens region 103a may be formed on both sides of the substrate portion 103b, or may be formed on the entire surface of the substrate portion 103b.

[0029] The function and precision of the microlens array vary depending on the shape (spherical, aspherical, cylindrical, hexagonal, etc.) of each lens element 1030a constituting the lens region 103a, the size of the lens elements 1030a, the arrangement of the lens elements 1030a, the pitch between the lens elements 1030a, etc. The light source control unit 101, the irradiation light source 102, and the irradiation optical system (microlens array) 103 are unitized and treated as an optical module 108, thereby improving the ease of assembly and management of the distance measurement device 100. The lens elements 1030a in the microlens array correspond to the optical elements of the present disclosure, and the lens region 103a corresponds to the optical region of the present disclosure. Examples of materials for the microlens array include resin materials such as polycarbonate, PMMA, and cycloolefin copolymer. The type of material is not particularly limited.

[0030] Fig. 10 shows an example of the configuration of a conventional optical module. Fig. 10(a) shows an optical module 110 using a microlens array 113 having a lens area 113a in which lens elements are arranged over substantially the entire lower surface of a flat substrate portion 113b. Here, the optical module 110 includes a housing 111 having a base portion 111a on which a light source 112 is installed and a side wall portion 111b surrounding the periphery of the light source 112. The microlens array 113 is fixed to the side wall portion 111b by having an end portion placed on a step portion 111c provided on the inner side of the side wall portion 111b and adhered with adhesive 115.

[0031] In this example, adhesive 115 may flow into lens region 113a due to capillary action caused by the unevenness of the lens elements in lens region 113a, affecting the optical performance of lens region 113a. Even if an adhesive with high viscosity is used by, for example, filling it with filler, there is a risk that adhesive 115 may flow into lens region 113a due to capillary action caused by the unevenness of the lens elements.

[0032] 10(b) shows an optical module 120 having a microlens array 123 in which a lens region 123a is provided in the center of the lower surface of a flat substrate portion 123b. Here, the optical module 120 includes a housing 121 having a base portion 121a on which a light source 122 is installed and a side wall portion 121b surrounding the periphery of the light source 122. An end of the microlens array 123 is placed on a step portion 121c provided inside the side wall portion 121b, and is fixed to the side wall portion 121b by being adhered with adhesive 125.

[0033] In this example, the underside of the microlens array 123 has a peripheral portion 123d, which is a transparent flat peripheral region where no lens elements are formed. Therefore, the possibility that the adhesive 125 will flow into the lens region 123a and affect the optical performance of the lens region 123a is lower than in the case of Figure 10(a). However, there is a possibility that the light emitted from the light source 122 will pass through the peripheral portion 123d, and high-intensity light that is not diffused by the lens elements will leak directly to the outside. In this case, there is a risk of the so-called eye-safe problem occurring, in which high-intensity leaked light is directly incident on the eyes of an outside person.

[0034] Therefore, in this example, in order to prevent direct irradiation with the leaked light from peripheral portion 123d, it is necessary to provide a light-shielding cover 126 at the position where the leaked light exits above microlens array 123. This results in an increase in the number of manufacturing steps and parts for optical module 120, resulting in an increase in the cost of optical module 120. Furthermore, the height of optical module 120 needs to be increased by the amount of cover 126, which also hinders efforts to make optical module 120 more compact.

[0035] FIG. 1 shows a schematic diagram of an optical module 1 according to this embodiment. FIG. 1(a) is a plan view of the optical module 1, and FIG. 1(b) is a cross-sectional view taken along the line AA. The optical module 1 includes a housing 10 serving as a holding member, which includes a base 10a on which a light source 2 is installed and sidewalls 10b surrounding the light source 2 on all four sides. The light source 2 may be, for example, a VCSEL (Vertical Cavity Surface Emitting Laser) laser light source. A light source control unit (not shown) is also mounted on the base 10a. A step 10c is provided on the inner wall of the sidewall 10b as a horizontal mounting surface on which a microlens array 3 is mounted. The microlens array 3 is mounted on the step 10c and fixed to the sidewall 10b by being bonded with an adhesive 5. In this embodiment, the sidewall 10b has a substantially square shape in a plan view; however, the shape of the sidewall 10b in a plan view is not limited thereto. It may have a shape such as a rectangle, a polygon, a circle, an ellipse, etc. Examples of the adhesive 5 include epoxy-based, acrylic-based and silicone-based adhesives.

[0036] The microlens array 3 has a substantially flat substrate 3b. The central portion of the bottom surface of the substrate 3b has a recess 3c that is rectangular in plan view, and a lens region 3a in which lens elements are arranged is formed on the top surface of the recess 3c. The region around the recess 3c on the bottom surface of the microlens array 3 forms a rib 3d as a peripheral region in which the optical function of the optical element is not used. As a result, the thickness of the rib 3d is greater than the thickness of the recess 3c. The microlens array 3 is bonded and fixed by placing the rib 3d on a step portion 10c and applying adhesive 5 between the step portion 10c and the rib 3d.

[0037] Furthermore, a light-shielding diffusion portion 3e that blocks or diffuses leakage of light emitted from the light source 2 is provided in an area corresponding to the rib 3d on the upper surface of the microlens array 3. The light-shielding diffusion portion 3e may have only a light-shielding function or only a light-diffusing function. Alternatively, it may have both a light-diffusing function and a light-shielding function. The light-shielding function of the light-shielding diffusion portion 3e may be a function of completely blocking transmitted light or a function of reducing the intensity of transmitted light. The light-shielding diffusion portion 3e may be provided by forming a light-shielding photoresist film using, for example, photolithography technology. Alternatively, the light-shielding diffusion portion 3e may be provided as a roughened surface by surface roughening using blasting technology. The surface roughness of the roughened surface is greater than the surface roughness of the base portion 3b. The surface roughness of the base portion 3b refers to the surface roughness of the base portion 3b other than the lens region 3a and the light-shielding diffusion portion 3e. The surface roughness of the substrate 3b includes the surface roughness of the side surface 3f of the substrate 3b if the entire upper and lower surfaces of the substrate 3b are covered with the lens region 3a and the light-shielding diffusion portion 3e. The region where the light-shielding diffusion portion 3e is provided is roughly the region corresponding to the rib 3d on the surface opposite the lens region 3a, but this does not have to be the exact region corresponding to the rib 3d, and may be a region including the region corresponding to the rib 3d, or may be a part of the region corresponding to the rib 3d.

[0038] According to this configuration, in the optical module 1, the light emitted from the light source 2 and incident on the rib 3d is blocked or diffused by the light blocking and diffusing portion 3e. Light from the EL laser light source does not leak directly, and it is possible to avoid the risk of high-intensity laser light being directly irradiated to the outside.

[0039] Furthermore, with this configuration, it is possible to lower the height of the upper end portion 10d, which is the thin portion above the step portion 10c on the side wall portion 10b, to the same height as the upper surface of the microlens array 3, thereby making it possible to lower the height of the entire optical module 1.

[0040] Furthermore, according to this configuration, the ribs 3d are formed around the lens regions 3a of the microlens array 3, so even if the adhesive 5 flows out from the step portions 10c, the adhesive 5 is unlikely to reach the lens regions 3a, thereby preventing the adhesive 5 from affecting the optical properties of the microlens array 3. In the first place, capillary action is unlikely to occur on the underside of the ribs 3d, so the adhesive 5 is unlikely to flow out.

[0041] FIG. 2 shows an enlarged view of the optical module 1 near the step portion 10c. In this embodiment, when the horizontal width of the rib 3d is A and the distance between the end face of the recess 3c and the end face of the step portion 10c (= the inner wall of the sidewall portion 10b) is B, the relationship B≧0.3×A should be satisfied. This more reliably prevents the adhesive 5 from flowing out of the step portion 10c and reaching the lens region 3a of the microlens array 3. More preferably, the relationship 0.7×A≧B≧0.5×A should be satisfied. This more reliably prevents the adhesive 5 from flowing out of the step portion 10c and reaching the lens region 3a of the microlens array 3. Furthermore, this ensures a sufficient contact area between the step portion 10c and the rib 3d, thereby stably fixing the microlens array 3 to the sidewall portion 10b. Note that an anti-reflection coating (not shown) may be applied to at least one of the lens region 3a and the opposite surface of the microlens array 3 in this embodiment. The anti-reflection film may be made of silica (Si) or titanium (Ti), or may have a moth-eye structure. The moth-eye structure may be formed simultaneously with the process of forming the light-shielding diffusion portion 3e.

[0042] <Variation 1> FIG. 3 shows a modified example of this embodiment. In this modified example, the light-shielding and diffusing portion 13e is provided on the rib 13d on the lower surface of the microlens array 13. This prevents the light emitted from the light source 2 from entering portions other than the lens region 13a of the microlens array 13, and blocks or diffuses leaked light from the source. This further reduces the height of the upper end 10d of the sidewall portion 10b. It also makes it possible to suppress the occurrence of flare caused by stray light within the microlens array 3.

[0043] <Modifications 2 and 3> FIG. 4(a) shows a second modified example of this embodiment. In this modified example, the microlens array 23 does not have a recess, and the lens region 23a is provided directly on the lower surface of the base portion 23b. The light-shielding diffusion portion 23e is provided on the upper surface of the base portion 23b. That is, in this modified example, the lens region 23a and the peripheral portion 23d, which serves as the peripheral region around the lens region 23a, are arranged on approximately the same plane. By doing so, the height of the microlens array 23 and the upper end portion 10d can be reduced by the amount that the ribs can be omitted, and the height of the optical module 21 can also be reduced.

[0044] FIG. 4(b) shows a third modified example of this embodiment. In this modified example, the microlens array 33 does not have a recess, and the lens area 33a is provided directly on the lower surface of the base material 33b. The light-shielding diffusion portion 33e is provided in the peripheral portion 33d, which is the peripheral area around the lens area 33a on the lower surface of the base material 33b. By doing so, the height of the microlens array 33 can be reduced by the amount that the ribs can be omitted. In addition, the light emitted from the light source 2 This prevents light from entering areas other than the lens region 33a of the microlens array 33, and blocks or diffuses leaked light from the source. This further reduces the height of the upper end 10d of the sidewall 10b. It also makes it possible to suppress flare caused by stray light within the microlens array 33.

[0045] <Variation 4> 5 shows a fourth modified example of the present embodiment. In this modified example, a light-shielding diffusion portion 43e is provided on a rib 43d on the lower surface of the microlens array 43 using an adhesive 5. That is, in this modified example, a colored adhesive 5 that blocks incident light from the light source 2 is used as the adhesive interposed between the rib 43d of the microlens array 43 and the step portion 10c of the side wall portion 10b.

[0046] The adhesive is also distributed on the surface of the rib 43d to form a light-shielding / diffusing portion 43e. This prevents light from the light source 2 from entering portions other than the lens region 43a of the microlens array 43, and blocks or diffuses leaked light from the source. This further reduces the height of the upper end 10d of the sidewall 10b. It also makes it possible to suppress flare caused by stray light within the microlens array 43.

[0047] Here, the light-shielding diffusion portion 43e using this adhesive 5 may be formed using only the adhesive 5, or may be used in combination with, for example, a light-shielding photoresist film formed using photolithography technology or surface roughening using blasting technology.

[0048] <Method of manufacturing a microlens array> Next, a method for manufacturing the microlens array 3 will be described. FIG. 6 is a flowchart illustrating the flow of the manufacturing method. In the example shown in FIG. 6(a), as shown in S01, the microlens array 3 is formed by simultaneously and integrally molding the base portion 3b, lens region 3a, recessed portion 3c, and rib 3d through a resin molding process. The process of S01 corresponds to a molding process. Then, as shown in S02, the light-shielding diffusion portion 3e is formed. The process for forming the light-shielding diffusion portion 3e is performed using, for example, the following method. (1) Photolithography A photoresist liquid is applied to the upper or lower surface of the integrally molded microlens array 3. Then, a photomask is placed over the portions of the lower surface other than the ribs 3d or the portions of the upper surface other than the areas corresponding to the ribs 3d, and the photoresist is exposed to light. The unexposed portions are then removed to form a light-shielding layer made of photoresist material over the ribs 3d or the areas of the upper surface corresponding to the ribs 3d. (2) Blast A mask is placed on the lower surface other than the ribs 3d or on the upper surface other than the area corresponding to the ribs 3d, and then air containing an abrasive is blown onto the upper or lower surface of the microlens array 3 to roughen the surface. (3) Other A mask is placed on the lower surface other than the ribs 3d or on the upper surface other than the area corresponding to the ribs 3d, and then the resin surface is altered by chemical, thermal or optical means to roughen the surface.

[0049] When the formation of the light-shielding diffusion portion 3e is completed, this routine ends. The step S02 corresponds to the light-shielding diffusion portion forming step. Note that if the methods (2) and (3) are performed in the step S02, this step corresponds to the roughening step.

[0050] In the example shown in FIG. 6(b), the above (2) is performed in advance in a mold for resin molding. Alternatively, the surface of the portion where the light-shielding diffusion portion 3e is to be formed is roughened by the method (3). Then, in the manufacturing process of the microlens array 3, the base portion 3b, lens region 3a, recessed portion 3c, rib 3d, and light-shielding diffusion portion 3e are simultaneously formed by integral molding using a resin molding process. This example further simplifies the manufacturing process of the microlens array 3.

[0051] 7 shows a flowchart for manufacturing the optical module 1. When manufacturing the optical module 1, in step S21, an adhesive is applied to the step portion 10c of the side wall portion 10b. Then, in this state, in step S22, the microlens array 3 is placed on and fixed to the step portion 10c. The step of applying the adhesive to the step portion 10c of the side wall portion 10b corresponds to the adhesive application step, and the step of placing and fixing the microlens array 3 on the step portion 10c corresponds to the fixing step.

[0052] In the above embodiments, the lens areas 3a, 13a, 23a, 33a, and 43a of the microlens arrays 3, 13, 23, 33, and 43 are provided on one side facing the light source 2, but the lens areas may be arranged on one side facing the light source 2. Furthermore, the lens areas may be arranged on both sides.

[0053] Furthermore, microlens arrays having functions equivalent to those of the microlens arrays 3, 13, 23, 33, and 43 described in this embodiment may be used as optical systems for image capture, facial recognition in security devices, and spatial recognition in vehicles and robots. Although this embodiment has been described assuming that the microlens arrays 3, 13, 23, 33, and 43 are made of a resin material, other resin materials such as thermoplastic resins, thermosetting resins, and photocurable resins may also be used. The materials of the microlens arrays 3, 13, 23, 33, and 43 are not limited to these. The optical elements constituting the optical modules 1, 11, 21, 31, and 41 may be made of resin or other materials such as glass. For example, a combination of resin and glass materials may be used, such as a structure in which a resin lens array is attached to a glass material. Regarding the manufacturing method of the microlens arrays, glass molding may be used instead of resin molding.

[0054] Although the optical modules 1, 11, 21, 31, and 41 in the present embodiment have been described as using a microlens array as an optical element, optical elements other than a microlens array may also be used as the optical element. For example, optical elements including a single lens, a Fresnel lens, a diffraction grating, etc. may be used as the optical element.

[0055] <Conductive wiring> In this embodiment, wiring containing a conductive material may be applied to the surface or inside of the microlens array 3, 13, 23, 33, or 43, and damage to each lens element in the lens region 3a, 13a, 23a, 33a, or 43a may be detected by monitoring the electrical conduction state of the wiring. This allows for easy detection of damage to each lens element, such as cracks or peeling, and prevents damage to the optical module 1, 11, 21, 31, or 41 due to damage to the microlens array 3, 13, 23, 33, or 43. For example, by detecting a crack in each lens element by detecting a break in the conductive material and prohibiting the light source from emitting light, zero-order light from the light source can be prevented from directly passing through the microlens array 3, 13, 23, 33, or 43 through the crack and irradiating the outside. As a result, the eye safety performance of the device can be further improved.

[0056] The conductive material wiring is formed on the peripheral portion (or rib) 3d, 13d, 23d, 33d, 43d of the microlens array and on the lens region 3a, 13a, 23a, 33a, 43a. The conductive material may be applied to any of the surfaces on which the lens regions 3a, 13a, 23a, 33a, and 43a are formed, the opposite surface, and both surfaces. The conductive material is not particularly limited as long as it is conductive, and examples thereof include metals, metal oxides, conductive polymers, and conductive carbon-based materials.

[0057] More specifically, metals include gold, silver, copper, chromium, nickel, palladium, aluminum, iron, platinum, molybdenum, tungsten, zinc, lead, cobalt, titanium, zirconium, indium, rhodium, ruthenium, and alloys thereof. Metal oxides include chromium oxide, nickel oxide, copper oxide, titanium oxide, zirconium oxide, indium oxide, aluminum oxide, zinc oxide, tin oxide, and composite oxides thereof, such as composite oxide of indium oxide and tin oxide (ITO) and composite oxide of tin oxide and phosphorus oxide (PTO). Conductive polymers include polyacetylene, polyaniline, polypyrrole, and polythiophene. Conductive carbonaceous materials include carbon black, SAF, ISAF, HAF, FEF, GPF, SRF, FT, MT, pyrolytic carbon, natural graphite, and artificial graphite. These conductive materials can be used alone or in combination.

[0058] The conductive material is preferably a metal or metal oxide, which has excellent conductivity and is easy to form wiring. Metal is more preferable, and gold, silver, copper, indium, etc. are preferred. Silver is preferred because it fuses to each other at a temperature of about 100°C and can form wiring with excellent conductivity even on a resin microlens array. The pattern shape of the wiring made of the conductive material is not particularly limited. It may be a pattern that surrounds the periphery of the microlens arrays 3, 13, 23, 33, and 43, or the pattern may have a complex shape to further improve the detectability of cracks, etc. Furthermore, a pattern that covers at least a portion of the microlens arrays 3, 13, 23, 33, and 43 with a transparent conductive material is also acceptable. [Explanation of symbols]

[0059] 1, 11, 21, 31, 41... Microlens array 1a, 11a, 21a, 31a, 41a... Lens area 1b, 11b, 21b, 31b, 41b...Base material part 1c, 11c, 41c...recess 1d, 11d, 21d, 31d, 41d... Periphery 1e, 11e, 21e, 31e, 41e... Light-shielding diffusion section 2...Light source 5. Adhesive 10. Housing 10a...base 10b...Side wall part 10c...Stepped section 10d...Tip 100...TOF distance measurement device 101 Light source control unit 102...Light source 103...Irradiation optical system 104...Reflection optical system 105....Photodetector 106 Signal processing circuit

Claims

1. An optical region in which optical elements are arranged on a portion of at least one surface of a plate-shaped substrate; a peripheral region on the surface of the base member where the optical region is provided, the peripheral region being provided around the optical region and where the optical elements are not disposed; a light-shielding / diffusing portion provided in the peripheral region and / or a region corresponding to the peripheral region on the opposite surface of the base portion, the light-shielding / diffusing portion suppressing light transmission or diffusing light; Equipped with the optical region is formed on a bottom surface of a recess that is rectangular in plan view and rectangular in cross section relative to the peripheral region on a surface of the base member where the optical region is provided, a surface of the base member on which the optical region is not provided is a plane perpendicular to a thickness direction of the base member, The peripheral side of the peripheral region and the side surface of the base portion have adhesive regions to be adhered when fixed, An optical element, wherein the width of the region other than the adhesive region in the peripheral region is 0.5 to 0.7 times the width of the peripheral region.

2. The optical element according to claim 1 , wherein the optical element is a lens element, and the optical region is a lens region in which a plurality of the lens elements are arranged.

3. 3. The optical element according to claim 1, wherein the light-shielding diffusion portion has a film of a photoresist material formed in the peripheral region and / or in a region corresponding to the peripheral region on the opposite surface of the base portion.

4. 4. The optical element according to claim 1, wherein the light-shielding diffusion portion has a roughened surface in which the surface roughness of the peripheral region and / or the region corresponding to the peripheral region on the opposite surface of the substrate is greater than that of the side surface of the substrate.

5. The optical element according to claim 1 , a light source that causes light to be incident on the optical element; a holding member that holds the optical element and the light source; Equipped with the holding member has a base portion to which the light source is fixed, and sidewall portions that are provided perpendicular to the base portion so as to surround the periphery of the light source from all sides, and to which the optical element is fixed; a step is provided in a part of an inner wall of the side wall portion, and a surface of the step that is parallel to the base portion serves as a mounting surface on which the peripheral region of the optical element is mounted, An optical module in which a predetermined adhesive is interposed between the outer periphery of the peripheral region as the adhesive region and the mounting surface, and between the side of the base portion as the adhesive region and a surface perpendicular to the base portion at the step.

6. The optical module according to claim 5 , wherein the upper end of the side wall portion is formed to be flush with or lower than the upper surface of the optical element.

7. 7. The optical module according to claim 5, wherein the predetermined adhesive has a light-shielding property and forms the light-shielding diffusion portion.

8. 7. A method for manufacturing an optical module according to claim 5 or 6, comprising the steps of: an adhesive application step of applying the predetermined adhesive to the placement surface and a surface of the step in the holding member that is perpendicular to the base portion; a fixing step of placing the optical element on the mounting surface to which the predetermined adhesive has been applied, inside a surface perpendicular to the base portion of the step, and fixing the optical element so that the predetermined adhesive is interposed between the outer periphery of the peripheral region as the adhesive region and the mounting surface, and between the side of the base portion as the adhesive region and the surface perpendicular to the base portion of the step.

9. The method for manufacturing an optical module according to claim 8 , wherein the predetermined adhesive has a light-blocking property.

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