Optical component, light receiving device, distance measuring device, mobile body

Abstract

The present invention relates to an optical member, a light-receiving device, a distance measuring device, a moving body, and a method for manufacturing an optical member, and aims to provide an optical member capable of suppressing yellowing of a resin base material and film lifting between the resin base material and a film provided on a surface thereof. An optical member of the present invention has a film with a multilayer structure on a surface of a resin base material, the film including a first film and a second film, the first film having a larger defect density than the second film and being formed on one side of the resin base material, and the second film having a smaller defect density than the first film and being formed on an outer side than the first film.

Description

Technical Field

[0001] This invention relates to optical components, light receiving devices, distance measuring devices, moving bodies, and methods for manufacturing optical components. Background Technology

[0002] Optical components, such as optical lenses, are used as optical elements in light receiving devices and distance measuring devices equipped with light receiving devices. Optical components are generally made of materials such as glass, quartz, and resin. Among them, optical components made of resin are used in various fields because they are lighter, less prone to breakage, have better manufacturing performance, and can be mass-produced inexpensively compared to optical components made of materials such as glass and quartz.

[0003] Typically, when optical components are used as optical lenses in light-receiving devices such as cameras, they are required to have high performance in terms of heat resistance, moisture resistance, and durability. In addition, due to the wide-angle effect, the shape of optical lenses becomes more complex and the aspect ratio increases, thus increasing the necessity of forming a uniform protective layer on the resin substrate that is susceptible to external atmospheric influences.

[0004] In this regard, existing technologies, such as Patent Document 1 (JP Patent No. 5250851), disclose a plastic optical element with a gas-barrier film disposed on its entire surface. This optical element is a resin optical component, in which a first film with gas-barrier properties is disposed in, for example, the optical path area on the surface, and a second film with gas-barrier properties having greater extensibility than the first film is disposed in the area outside the optical path on the surface.

[0005] However, the inventors have discovered that if the protective film cannot adequately protect the resin-made optical components, the components will yellow. Furthermore, they have found that some protective films exhibit film lifting issues. Therefore, there is still room for improvement in the protective film for resin-made optical components. Summary of the Invention

[0006] The purpose of this invention is to provide an optical component capable of suppressing yellowing of a resin substrate and film lift-off between the resin substrate and the film disposed on its surface.

[0007] The present invention provides an optical component having a multilayer film on the surface of a resin substrate, characterized in that the film includes a first film and a second film, wherein the first film has a larger defect density than the second film and is formed on one side of the resin substrate, and the second film has a smaller defect density than the first film and is formed on the outer side of the first film.

[0008] The advantage of this invention is that it can suppress yellowing of optical components and film lift-off between the resin substrate and the film disposed on its surface. Attached Figure Description

[0009] Figure 1 This is a top view of the optical component according to an embodiment of the present invention.

[0010] Figure 2 yes Figure 1 AA-plane cross-sectional view.

[0011] Figure 3-1 yes Figure 2 A cross-sectional view of a multilayer structure of a membrane.

[0012] Figure 3-2 yes Figure 2 Cross-sectional views of the multilayer structure of other membranes in the image.

[0013] Figure 4 yes Figure 2 A cross-sectional view of the multilayer structure of the membrane.

[0014] Figure 5 This is a schematic diagram showing that the entire surface of the resin substrate is covered by a second protective layer.

[0015] Figure 6-1 This is a cross-sectional view of another example of an optical element using optical components.

[0016] Figure 6-2 This is a cross-sectional view of another example of an optical element using optical components.

[0017] Figure 6-3 This is a cross-sectional view of another example of an optical element using optical components.

[0018] Figure 6-4 This is a cross-sectional view of another example of an optical element using optical components.

[0019] Figure 6-5 This is a cross-sectional view of another example of an optical element using optical components.

[0020] Figure 7 This is a simplified illustration of a car equipped with a lidar device.

[0021] Figure 8 This is a simplified diagram of a lidar device.

[0022] Figure 9 This is a schematic diagram of another distance measuring device.

[0023] Figure 10 This is a schematic diagram of an example of a camera device. Detailed Implementation

[0024] The embodiments of the present invention are described in detail below. For ease of understanding, the same symbols are used to label the same constituent elements in the various drawings, and repeated descriptions are omitted. The proportions of the components in the drawings may sometimes differ from the actual figures. In this specification, the symbol "~" indicating a numerical range means, unless otherwise specified, that the values ​​described before and after it are included as the lower and upper limits.

[0025] [Optical Components]

[0026] The optical components involved in the embodiments of the present invention are described below. In this embodiment, the optical component is an optical lens. Figure 1 This is a top view of the optical component in this embodiment. Figure 2 yes Figure 1 AA section diagram. Figure 1 and Figure 2 A three-dimensional orthogonal coordinate system with three axes (X-axis, Y-axis, and Z-axis) is used. The direction parallel to the central axis J of the optical component (thickness direction) is the Z-axis. In the plane orthogonal to the central axis J, one of the two mutually orthogonal directions is the X-axis and the other is the Y-axis.

[0027] like Figure 1 and Figure 2 As shown, the optical component 1 of this embodiment has a resin substrate 10 and a multilayer film 20.

[0028] Resin substrate 10 Figure 1 As shown, it is roughly circular in the top view. In the plan view, the resin substrate 10 may also have a notch cut into a straight line (orientation plane, orientation reflector) on a part of its shape as a marker to determine the direction.

[0029] like Figure 2 As shown, the resin substrate 10 has a first protrusion 11 on its upper surface 10a. The region A1 between the vertices P1 and P2 of the first protrusion 11 of the resin substrate 10 has a curved surface 11a containing a concave surface.

[0030] The lower surface 10b of the resin substrate 10 has a second protrusion 12 and a groove 13 formed circumferentially along the second protrusion 12. The region A2 between the apex P3 and the apex P4 of the second protrusion 12 of the resin substrate 10 has a curved surface 12a containing a concave shape.

[0031] The shape of the resin substrate 10 can be designed into any shape according to the application of the optical component 1. The shape and size of the first protrusion 11 and the second protrusion 12 can also be designed into any shape according to the application of the optical component 1, or it can be a shape without the first protrusion 11 and the second protrusion 12.

[0032] The resin substrate 10 is used for the optical component 1; therefore, it is preferable that the resin used for the resin substrate 10 has visible light transmittance.

[0033] Having light transmittance means that when visible light (light with a wavelength of 380 nm to 780 nm) is irradiated from the outside of the resin substrate 10, it can pass through the interior of the resin substrate 10. The visible light transmittance of the resin substrate 10 is preferably 60% or more, more preferably 75% or more, and even more preferably 90% or more. The visible light transmittance can be determined by averaging the transmittance at various wavelengths measured using a spectrophotometer within the wavelength range of 380 nm to 780 nm.

[0034] Resins that can be used in resin substrate 10 include polyester resins, cellulose resins, polyolefin resins, acrylic resins, styrene resins, polycarbonate (PC), vinyl chloride resins, amide resins, imide resins, sulfone resins, polyethersulfone resins, polyetheretherketone resins, polyphenylene sulfide resins, vinyl alcohol resins, vinylidene chloride resins, polyvinyl butyral resins, aromatic resins, polyoxymethylene resins, and epoxy resins. These resins can be used alone or in combination.

[0035] Polyester resins include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), and polycyclohexanedimethyl terephthalate (PCT).

[0036] Examples of cellulose-based resins include cellulose diacetate and cellulose triacetate (TAC).

[0037] Polyolefin resins include polyethylene (PE), polypropylene (PP), polymethylpentene, polyolefins with cyclic and norbornene structures, cyclic olefin copolymers, and ethylene-propylene copolymers. Specific polyolefin resins that can be used include polymethylpentene (TPX (registered trademark), manufactured by Mitsui Petrochemical Co., Ltd.), cyclic olefin copolymers (APELAPL3500 (APO), manufactured by Mitsui Petrochemical Co., Ltd.), cyclic olefin polymers (COP) (ZEONNEX (registered trademark), manufactured by Japan Zeon Co., Ltd.), and ARTON resin (manufactured by Japan Synthetic Rubber Co., Ltd.). These materials generally have low heat resistance at high temperatures and are therefore processed in manufacturing processes below 160°C. For this reason, these materials are suitable for use in manufacturing at low temperatures below 160°C.

[0038] Acrylic resins include polymethyl methacrylate (PMMA), etc.

[0039] Examples of styrene-based resins include polystyrene (PS) and acrylonitrile-styrene copolymer (AS resin).

[0040] Examples of vinyl chloride resins include polyvinyl chloride (PVA).

[0041] Amide resins include nylon and aromatic polyamides, among others.

[0042] Resin substrate 10 Figure 2 As shown, there are regions A1, A2, A3-1 and A3-2, A4-1 and A4-2, and A5-1 and A5-2.

[0043] Region A1 corresponds to the region forming surface 11a, i.e., the surface between vertices P1 and P2. Region A2 corresponds to the region formed by the region forming surface 12a, i.e., the surface between vertices P3 and P4. Regions A1 and A2 can be adapted to the design of the resin substrate 10.

[0044] Preferred regions A1 and A2 include the effective regions of optical component 1. The effective region refers to the area through which light passes after incident or reflection.

[0045] Regions A3-1 and A3-2 are located further outward from the axial direction of optical component 1 than the effective area of ​​optical component 1. They are regions formed on the flat surface of optical component 1 and are not easily affected by optical influences.

[0046] Regions A4-1 and A4-2 are located further outward from the axial direction of the optical component 1 than the effective area of ​​the optical component 1. They are formed on the bottom surface of the groove portion 13 and are not easily affected by optics.

[0047] Regions A5-1 and A5-2 are located further outward from the axial direction of the optical component 1 than the effective area of ​​the optical component 1. They are regions formed on the outer peripheral surface of the first protrusion 11 and are the regions between region A1 and region A3-1 or region A3-2.

[0048] like Figure 2 As shown, a multilayer membrane 20 is disposed on the surface of the resin substrate 10. The membrane 20 includes a first protective layer 21, which corresponds to a first membrane, and a second protective layer 23, which corresponds to a second membrane, formed by lamination.

[0049] The first protective layer 21 contains more defects than the second protective layer 23. Because of these defects, the first protective layer 21 has the function of absorbing emitted elements and gaseous components.

[0050] The second protective layer 23 is a high-quality film with fewer defects than the first protective layer 21, and has the function of preventing elements that affect the resin substrate 10 from intruding from the outside.

[0051] In addition to the multilayer film 20A, the optical component 1 also has a film 20B.

[0052] The resin substrate 10 has a first region where a multilayer structure of film 20A is formed and a second region where a film 20B is formed. Figure 2 To clearly distinguish between membrane 20A and membrane 20B, the area of ​​membrane 20A is represented by a thick line.

[0053] like Figure 2 As shown, the film 20A is disposed in regions A1, A2, A3-1 and A3-2, and A4-1 and A4-2 on the surface of the resin substrate 10. In this embodiment, regions A1, A2, A3-1 and A3-2, and A4-1 and A4-2 correspond to the first region.

[0054] like Figure 2 As shown, the membrane 20B is disposed in regions A5-1 and A5-2 on the surface of the resin substrate 10, namely the outer peripheral surface of the first protrusion 11, the side surface of the groove 13, and the outer periphery and vicinity of the resin substrate 10.

[0055] Figure 3-1 yes Figure 2 A cross-sectional view of the laminated structure of the intermediate film 20A. Since the surface of the resin substrate 10 is curved, the film 20A is also curved, but in Figure 3, the surface of the resin substrate 10 is shown as flat.

[0056] like Figure 3-1 As shown, film 20A is a laminated film formed by sequentially stacking a first protective layer 21, an anti-reflection layer 22, and a second protective layer 23. The anti-reflection layer 22 is not necessary; it can be omitted, or it can be formed only in a portion of the first protective layer 21. In this case, film 20A can also be as follows... Figure 3-2 As shown, it is a laminated film formed by sequentially stacking the first protective layer 21 and the second protective layer 23.

[0057] Figure 4 This is a cross-sectional view of the layer structure of membrane 20B. (Example) Figure 4 As shown, membrane 20B does not have the laminated film of the first protective layer 21 and the anti-reflection layer 22 of membrane 20A, but has a second protective layer 23. Membrane 20B is not limited to a single membrane, and other membranes may also be laminated on the second protective layer 23.

[0058] A first protective layer 21 is disposed on the bottom surface of the grooves 13 in regions A1, A2, A3-1 and A3-2, and A4-1 and A4-2 on the surface of the resin substrate 10. By disposing the first protective layer 21 on the surface of these regions of the resin substrate 10, the first protective layer 21 can suppress the release of gaseous components contained in the resin substrate 10 and gaseous components in the anti-reflection layer 22 caused by the manufacturing process of the resin substrate 10. Therefore, in the regions where the first protective layer 21 is formed, the accumulation of gaseous components released from the resin substrate 10 and the anti-reflection layer 22 between these layers and the second protective layer 23 can be suppressed.

[0059] Most of the gaseous components contained in the resin substrate 10 are released during the formation of the first protective layer 21 on the surface of the resin substrate 10, but a portion remains. This remaining portion of the gaseous components is released from the resin substrate 10 when the optical component 1 is used. The first protective layer 21 absorbs the portion of the gaseous components remaining in the resin substrate 10, thus suppressing its release to the outside.

[0060] The first protective layer 21 can be provided on a portion of the surface of the resin substrate 10. In addition to the bottom surface of the groove 13 in regions A1, A2, A3-1 and A3-2, and A4-1 and A4-2, it can also be provided on the rising portion (wall) of the groove 13 or in regions A5-1 and A5-2.

[0061] Preferably, the first protective layer 21 is provided at least within the effective area of ​​the optical component 1, while the outer periphery and its vicinity of the resin substrate 10 in top view, and the area outside the effective area of ​​the optical component 1, may not be provided. The outer periphery and its vicinity refer to the area that is further outward from the resin substrate 10 than regions A3-1 and A3-2, regions A4-1 and A4-2, and the groove portion 13. The vicinity of the outer periphery of the resin substrate 10 is the location where the first protective layer 21 does not function particularly effectively when the resin substrate 10 is held in place, fixed in a holding member (not shown), a light receiving device (not shown), or a distance measuring device.

[0062] The material forming the first protective layer 21 may be, for example, aluminum oxide.

[0063] The thickness of the first protective layer 21 can be designed arbitrarily, but it is preferably 10nm to 40nm, more preferably 15nm to 35nm, and even more preferably 20nm to 30nm. If the thickness of the first protective layer 21 is within the above-mentioned preferred range, it can perform its function as the first protective layer 21 while suppressing the generation of cracks in the first protective layer 21.

[0064] The thickness of the first protective layer 21 in this specification refers to its length in the direction perpendicular to the specified surface of the first protective layer 21. The thickness of the first protective layer 21 is, for example, the thickness measured at any position in its cross-section. When measurements are taken at multiple positions in any location within the cross-section of the first protective layer 21, the average thickness at these measurement positions can be taken. The thicknesses of the anti-reflective layer 22 and the second protective layer 23 can also be measured in the same manner as the thickness of the first protective layer 21.

[0065] Regarding the manufacturing method of the first protective layer 21, general film formation methods such as chemical vapor deposition (CVD), physical vapor deposition (PVD), and sputtering can be used. However, according to atomic layer deposition (ALD) described later, since it is possible to form a film with very few defects, it is preferred to manufacture the first protective layer 21 by any one of CVD, PVD, and sputtering.

[0066] As described above, the defect density of the first protective layer 21 is greater than that of the second protective layer 23. By making the first protective layer 21 have a larger defect density than the second protective layer 23, in addition to absorbing the emitted elements and gas components, when the anti-reflection layer 22 or the second protective layer 23 is formed on the surface of the first protective layer 21, a portion of these films can easily adhere to the surface of the first protective layer 21, thus also achieving a high degree of adhesion.

[0067] Defect density can be measured using any of the following instruments: scanning electron microscope (SEM), optical microscope, and transmission electron microscope (TEM). The defect density is calculated by determining the number of voids per unit area of ​​the cross-section of the first protective layer 21, obtained from images of the cross-section observed using SEM, TEM, etc. A defect can be any of the following: point defect, line defect, or surface defect.

[0068] The first protective layer 21 formed by vapor deposition or sputtering is as follows: Figure 2 As shown, a portion of the surface of the resin substrate 10 (regions A1, A2, A3-1 and A3-2, A4-1 and A4-2) is covered, but the entire surface of the resin substrate 10 is not completely covered.

[0069] In this embodiment, the resin substrate 10 is as follows: Figure 2 As shown, the first protrusion 11 of the resin substrate 10 has a shape that is upright on its outer periphery. Therefore, when the first protective layer 21 is formed on the surface of the resin substrate 10, even without the use of a mask or the like, the first protective layer 21 and the anti-reflection layer 22 can be formed only on a portion of the surface of the resin substrate 10 (regions A1, A2, A3-1 and A3-2, and A4-1 and A4-2).

[0070] The first protective layer 21 also serves to suppress the intrusion of oxygen-containing or other gaseous components generated by the anti-reflection layer 22 into the resin substrate 10, thereby preventing adverse effects on the resin substrate 10. Therefore, it is preferable that the first protective layer 21 is formed to at least cover the area where the anti-reflection layer 22 is formed.

[0071] like Figure 3-1 As shown, the anti-reflection layer 22 can be disposed between the first protective layer 21 and the second protective layer 23. Like the first protective layer 21, the anti-reflection layer 22 is disposed on a portion of the surface of the resin substrate 10 (regions A1, A2, A3-1 and A3-2, and A4-1 and A4-2). Like the first protective layer 21, the anti-reflection layer 22 may not cover the entire surface of the resin substrate 10. Figure 2 In this case, the areas where the first protective layer 21 and the anti-reflection layer 22 are formed are the same, but it is sufficient that the area where the anti-reflection layer 22 is formed is contained within the area where the first protective layer 21 is formed.

[0072] The anti-reflection layer 22 is a multilayer film consisting of layers of elements with different refractive indices that are periodically stacked. The anti-reflection layer 22 generally uses a multilayer reflective film, which is formed by alternately stacking a high refractive index layer that displays a high refractive index to light and a low refractive index layer that displays a low refractive index to light from one side of the first protective layer 21.

[0073] The anti-reflection layer 22 can be stacked in multiple cycles, either by sequentially stacking a high-refractive-index layer and a low-refractive-index layer starting from the first protective layer 21, or by sequentially stacking a low-refractive-index layer and a high-refractive-index layer, also in multiple cycles. When the low-refractive-index layer is SiO2, it is preferable that the anti-reflection layer 22 has a high-refractive-index layer on the side of the first protective layer 21. This reduces the impact of the low-refractive-index layer composed of SiO2, which is relatively easier to remove oxygen than other materials, on the oxygen content of the resin substrate 10.

[0074] Al2O3 and ZrO can be used as high refractive index layers. x (x is 1.5~2), TiO x (x is 1 to 2), TaO x (x is 2 to 2.5), NBO x (x is 2-2.5), HfO2 and CeF3, etc. ZrO x ZrO, ZrO2, and TiO are preferred. x TiO2, Ti3O5, Ti2O5, and TaO are preferred materials. x Ta2O5 and NBO are preferred. xNb₂O₅ is preferred. Even if the metal oxide is not stoichiometric, it is acceptable as long as the oxygen composition ratio is within the range of x mentioned above. Preferably, the high refractive index layer is formed from a single layer selected from the above components or a mixed layer containing two or more of them. The materials of the multiple high refractive index layers laminated within the anti-reflection layer 22 can be the same or different. By including at least one of these high refractive index layers, the anti-reflection layer 22 can have excellent light reflectivity.

[0075] Preferably, the low refractive index layer is formed from a single layer of SiO2, MgF2, CeO2, ZnS, or a mixed layer containing any of these. As low refractive index layers, the materials of the multiple low refractive index layers laminated on the anti-reflection layer 22 can be the same or different.

[0076] The anti-reflection layer 22 has multiple high refractive index layers and multiple low refractive index layers, but the thickness of each high refractive index layer or each low refractive index layer may not be the same.

[0077] The thickness and period of each layer constituting the anti-reflection layer 22 can be appropriately selected according to the film material used, the light reflectivity or light wavelength required by the anti-reflection layer 22, etc.

[0078] The layers constituting the anti-reflection layer 22 can be formed using common film deposition methods such as vapor deposition and sputtering to achieve the required film thickness. Sputtering methods include, for example, magnetron sputtering and ion beam sputtering.

[0079] like Figure 3-1 As shown, the second protective layer 23 is disposed on the entire surface including at least the resin substrate 10 and the first protective layer 21. That is, the second protective layer 23 is disposed on the surface of the resin substrate 10 not covered by the first protective layer 21 and on the surface of the first protective layer 21.

[0080] The preferred second protective layer 23 includes Al2O3, HfO2, and SiO2. x SiN x and TiO x At least one of them, more preferably Al2O3.

[0081] Preferably, the thickness of the second protective layer 23 is 10 nm to 40 nm, more preferably 15 nm to 35 nm, and even more preferably 20 nm to 30 nm. In the resin substrate 10 without the second protective layer 23, the transmittance loss exceeds 10% after 1000 hours at 120°C. In contrast, if the thickness of the second protective layer 23 is within the above-mentioned preferred range, the transmittance loss after 1000 hours at 120°C can be suppressed to below 8%. In particular, when the second protective layer 23 is formed as described later in the ALD process, if the thickness of the second protective layer 23 is 20 nm to 40 nm, the transmittance loss after 1000 hours at 120°C can be further reduced to 0.5%.

[0082] The uniformity of the film thickness of the second protective layer 23 can be expressed by the following formula (1), preferably 10% or less, more preferably 8% or less, and even more preferably 6% or less. If the uniformity of the film thickness of the second protective layer 23 is 10% or less, the second protective layer 23 can cover the entire resin substrate 10 with a substantially uniform film thickness, and can perform the function of the second protective layer 23.

[0083] Film thickness uniformity (%) = (maximum film thickness - minimum film thickness) / (average film thickness × 2) × 100 (1)

[0084] When the average film thickness in formula (1) is calculated using formula (2), the above formula (1) can be expressed by formula (3).

[0085] Average film thickness = (maximum film thickness + minimum film thickness) / 2 (2)

[0086] Film thickness uniformity (%) = (maximum film thickness - minimum film thickness) / (maximum film thickness + minimum film thickness) × 100 (3)

[0087] like Figure 2 As shown, since the second protective layer 23 is easily formed on a portion of the surface of the resin substrate 10 (regions A1, A2, A3-1 and A3-2, A4-1 and A4-2), the second protective layer 23 has the maximum thickness in these regions. On the other hand, the second protective layer 23 has the minimum thickness in regions of the resin substrate 10 with a high inclination, such as regions A5-1 and A5-2 and the side surface of the groove 13, because it is difficult to form. Therefore, it is preferable that the difference in film thickness between the second protective layer 23 formed on a portion of the surface of the resin substrate 10 (regions A1, A2, A3-1 and A3-2, A4-1 and A4-2), regions A5-1 and A5-2, and the second protective layer 23 formed on the side surface of the groove 13 is less than 10%.

[0088] The second protective layer 23 can be formed using general film deposition methods, but it is best formed using atomic layer deposition (ALD). ALD is a vacuum film deposition technology that utilizes the self-control of atoms to create a thin film on the surface of the anti-reflection layer 22, with each atomic layer forming a single layer. Compared with existing vapor phase growth methods (CVD, PVD), ALD can form films with fewer defects and can uniformly cover the surface of the anti-reflection layer 22.

[0089] The reasons why ALD is superior to CVD in the formation of the second protective layer 23 are explained below. Typically, when the second protective layer 23 is formed by CVD, it tends to contain many film defects. Furthermore, due to the high deposition rate of CVD (e.g., 10 nm / s to 15 nm / s), the layer can become thick enough to affect optical properties, making it difficult to control the thickness of the second protective layer 23 to within tens of nm. In contrast, ALD, because it forms a film layer per atomic layer, although the deposition rate is slower than CVD, is less prone to problems such as cracks in the second protective layer 23 or particles adhering to the interior or surface of the second protective layer 23, resulting in fewer film defects compared to CVD. Moreover, while films grown at high temperatures are generally considered to have advantages in terms of durability, ALD can form high-quality films at very low temperatures during vapor phase growth, making it suitable as a film formation method for resin substrates with limited heat resistance temperatures.

[0090] Furthermore, the coverage of the second protective layer 23 formed using ALD is better than that using CVD. Even if the resin substrate 10 has a conformal shape, the first protective layer 21 or the anti-reflection layer 22 can be formed with a generally uniform thickness along the shape of the resin substrate 10. When dissimilar materials such as the first protective layer 21 and the anti-reflection layer 22 are used to cover the entire surface of an irregularly shaped resin substrate 10, the film thickness on the sidewalls of the resin substrate 10 becomes thinner, making it easy to generate gaps. Therefore, it is difficult to control the film thickness of the second protective layer 23 to tens of nm in CVD. In contrast, since ALD is a film formation method that utilizes surface reaction, even a film as thin as 1 nm can reliably cover the first protective layer 21 and the anti-reflection layer 22, making the film thickness of the second protective layer 23 on the surface and sidewalls of region A of the resin substrate 10 generally uniform.

[0091] Since the second protective layer 23 is formed using ALD, it can cover the entire resin substrate 10 in a substantially uniform manner. Therefore, it can suppress the intrusion of moisture and oxygen from the outside and suppress the yellowing of the resin substrate 10 (deterioration of resin transmittance).

[0092] In this embodiment, the second protective layer 23 is preferably composed of aluminum oxide film formed by ALD with a thickness of 20 nm.

[0093] When forming the second protective layer 23 using ALD, the second protective layer 23 can be formed using general film-forming conditions. The forming conditions of ALD will be described below.

[0094] When the second protective layer 23 contains Al2O3, it is best to use an aluminum compound. Any aluminum compound that contains aluminum and can be vaporized is acceptable; for example, trimethylaluminum (TMA), triethylaluminum (TEA), and trichloroaluminum can be used.

[0095] The oxidant can be any material that can oxidize aluminum compounds, such as water vapor (H2O).

[0096] The preferred reaction temperature is below 140°C.

[0097] When the second protective layer 23 contains Al2O3, the properties of the second protective layer 23 largely depend on the Al2O3. It is known that although the refractive index of the Al2O3 film formed by ALD varies with the growth conditions, it is smaller than that of bulk Al2O3. Preferably, the refractive index of the second protective layer 23 containing Al2O3 relative to light with a wavelength of 550 nm is 1.630 or more and 1.670 or less, more preferably 1.640 or more and 1.660 or less.

[0098] When the first protective layer 21 and the second protective layer 23 are composed of the same compound, a lower defect density in the second protective layer 23 than in the first protective layer 21 means that the density of the second protective layer 23 is greater than that of the first protective layer 21. Generally, a higher refractive index results in a higher density; therefore, when the first and second protective layers 21 and 23 are composed of the same compound, it is preferable that the refractive index of the second protective layer 23 is greater than that of the first protective layer 21. For example, polarized light analysis shows that the refractive index of the Al2O3 film deposited by vapor deposition as the first protective layer 21 relative to light with a wavelength of 550 nm is approximately 1.595 to 1.610. The refractive index of the Al2O3 film deposited by ALD as the second protective layer 23 relative to light with a wavelength of 550 nm is approximately 1.649.

[0099] The effect of the multilayer film 20 having a first protective layer 21 and a second protective layer 23 will be explained here. When only the first protective layer 21 is provided as a protective film for the resin substrate 10, the resin substrate 10 will yellow depending on the condition of the optical components. This is believed to be because the first protective layer 21 contains defects, and the first protective layer 21 alone cannot completely block the influence of the external atmosphere, allowing external moisture and oxygen to affect the resin substrate 10. Furthermore, with conventional film-forming techniques, it is difficult to uniformly cover the stepped areas when the resin substrate 10 has uneven surfaces. On the other hand, for example, as... Figure 5As shown, when only the second protective layer 23 is provided as a protective film for the resin substrate 10, the film may lift at the interfaces of the resin substrate 10 and the anti-reflection layer 22, the interface of the anti-reflection layer 22 and the second protective layer 23, and the interface of the resin substrate 10 and the second protective layer 23. This is believed to be because the second protective layer 23 is a low-defect film, and the inner side of the second protective layer 23 is in a nearly completely airtight state, thus trapping elements and gases generated by the resin substrate 10 and the anti-reflection layer 22 inside the second protective layer 23.

[0100] If film levitation occurs in the effective area of ​​optical component 1 (e.g., area A1 and area A2, etc.), it may not be able to fully perform its function as optical component 1.

[0101] In this embodiment, the first protective layer 21 disposed on a portion of the surface of the resin substrate 10 at least covers the effective area of ​​the optical component 1. This is because, due to the characteristics of film formation methods such as CVD, PVD, and sputtering, it is difficult to cover the entire surface of the resin substrate 10. However, if the area where the first protective layer 21 is not disposed is outside the effective area of ​​the optical component 1, even if the film floats up, it will not have a significant impact on the function of the optical component 1.

[0102] On the other hand, the yellowing of the resin substrate 10 does not only occur in the parts without protective films such as the first protective layer 21 and the second protective layer 23, or in the defective parts of the protective film, but diffuses into the resin substrate 10. Therefore, it is preferable that the second protective layer 23, which prevents moisture or oxygen from entering from the outside, is provided at least in the effective area of ​​the optical component 1 and the area adjacent to the effective area, and more preferably covers the entire surface of the resin substrate 10.

[0103] Furthermore, there is a method that covers the effective area of ​​the resin substrate 10 with a resin layer, covers a portion of the resin substrate 10 outside the effective area (non-effective area) with a metal film, and covers the entire resin substrate (Patent Document 1 (JP Patent No. 5250851)). In this case, in order to avoid forming a metal film in the effective area, a mask forming process is required, thereby increasing the manufacturing process and the manufacturing burden. However, in this embodiment, the optical component 1 can cover the entire surface of the resin substrate 10 with the second protective layer 23, so there is no need to add a mask forming process, etc., and the manufacturing cost can be suppressed.

[0104] The manufacturing method of the optical component 1 in this embodiment is not particularly limited as long as it can manufacture an optical component 1 having a multilayer structure of a film 20 having a first protective layer 21 as a first film and a second protective layer 23 as a second film on the surface of the resin substrate 10. Therefore, a general optical component manufacturing method can be used.

[0105] The manufacturing method of the optical component 1 includes: a first film forming step, forming a first protective layer 21 on the surface of a resin substrate 10; and a second film forming step, forming a second protective layer 23 with a smaller defect density than the first protective layer 21 after the first protective layer 21 step, and may further include other steps.

[0106] The methods for forming the first protective layer 21 in the first film forming process and the methods for forming the second protective layer 23 in the second film forming process are described above, and therefore detailed descriptions are omitted.

[0107] The manufacturing of optical component 1 includes a first film forming process and a second film forming process, thereby forming optical component 1.

[0108] As described above, the optical component 1 according to this embodiment includes a resin substrate 10 and a multilayer film 20, the film 20 having a first protective layer 21 and a second protective layer 23. The first protective layer 21 has a relatively high defect density, while the second protective layer 23 has a relatively low defect density. Due to the presence of the second protective layer 23, the optical component 1 can primarily reduce the contact between external oxygen, moisture, etc., and the resin substrate 10. Furthermore, since the surface of the resin substrate 10 has the first protective layer 21, the optical component 1 can absorb gaseous components generated from the resin substrate 10 and the anti-reflection layer 22 using the first protective layer 21, reducing the accumulation of gaseous components generated by the resin substrate 10 between the resin substrate 10 and the second protective layer 23. Therefore, the optical component 1 can reduce yellowing of the resin substrate 10 and reduce film lifting between the resin substrate 10 and the film 20. Thus, it can suppress the deterioration of the optical component 1 during use and improve its long-term reliability.

[0109] Furthermore, by making the defect density of the first protective layer 21 relatively greater than that of the second protective layer 23, the optical component 1 can easily make the second protective layer 23 adhere tightly to the first protective layer 21. Therefore, even if the adhesion between the resin substrate 10 and the second protective layer 23 is low, the second protective layer 23 can still be stably placed on the resin substrate 10 through the first protective layer 21.

[0110] The optical component 1 can have a first protective layer 21 disposed in a first region and a second protective layer 23 disposed in both the first and second regions. The optical component 1 can also have the first protective layer 21 and the second protective layer 23 disposed on a portion of the surface of the resin substrate 10. In this case, the optical component 1 can also reduce yellowing of the resin substrate 10 and reduce film lift-off between the resin substrate 10 and the film 20. Therefore, the optical component 1 can stably perform its optical properties.

[0111] The first region of the optical component 1 is composed of multiple regions including region A1, region A2, regions A3-1 and A3-2, and regions A4-1 and A4-2. Therefore, the optical component 1 can form the first region in multiple regions of the resin substrate 10, thereby reducing film lift-up between the resin substrate 10 and the film 20 and stably exhibiting optical properties.

[0112] The optical component 1 may have an anti-reflection layer 22 in at least a portion between the first protective layer 21 and the second protective layer 23. In this case, the optical component 1 can also suppress yellowing of the resin substrate 10 and allow light to be incident on and reflected into regions A1 and A2 of the resin substrate 10. Therefore, the optical component 1 can stably perform its optical properties.

[0113] The second protective layer 23 of the optical component 1 may contain Al2O3, HfO2, SiO x SiN x and TiO x At least one compound in it. Thus, the second protective layer 23 can appropriately inhibit the intrusion of moisture and oxygen from the outside to the inside, thereby enabling the optical component 1 to further suppress the yellowing of the resin substrate 10.

[0114] The thickness of the second protective layer 23 of the optical component 1 can be 10 nm to 40 nm. In this way, the second protective layer 23 can suppress the transmittance loss after 1000 hours at 120°C, thus suppressing the intrusion of external gaseous components such as air and oxygen. Therefore, the second protective layer 23 of the optical component 1 can suppress the intrusion of external moisture, oxygen, etc., further ensuring reduced yellowing of the resin substrate 10.

[0115] The second protective layer 23 of the optical component 1 may comprise aluminum oxide with a refractive index of 1.630 to 1.670 relative to light with a wavelength of 550 nm. In this way, the optical component 1 can maintain its optical properties while inhibiting the intrusion of external elements such as moisture and oxygen. Therefore, the optical component 1 can maintain its optical properties while suppressing yellowing of the resin substrate 10.

[0116] The thickness difference of the second protective layer 23 of the optical component 1 can be controlled within 10%. This improves the uniformity of the thickness of the second protective layer 23, thereby suppressing functional inhomogeneity of the second protective layer 23. Therefore, the optical component 1 can more stably suppress yellowing of the resin substrate 10 while maintaining optical properties.

[0117] The optical component 1 can use a film formed by ADL (Advanced Direct Adaptive Processing) to create the second protective layer 23. This allows the second protective layer 23 to become a thin film. Thus, even if the optical component 1 is made very thin, yellowing of the resin substrate 10 can be suppressed while maintaining optical properties.

[0118] The region A1 of the optical component 1 may include an effective region of the optical component 1. The effective region is the area through which external light is reflected and passes while incident. The optical component 1 has a first protective layer 21 and a second protective layer 23 in the region A1, and can reliably suppress yellowing and film lifting of the resin substrate 10 in the effective region. Therefore, the optical component 1 can suppress the irradiation of external light in the first region A1 and the obstruction of reflected light, thereby reliably exhibiting high optical properties.

[0119] As described above, the optical component 1 can reliably suppress yellowing and film lifting of the resin substrate 10, and therefore, in addition to resin-based optical lenses, it can also be used for various optical elements based on resin.

[0120] Figures 6-1 to 6-5 This shows a cross-sectional view of another example using optical component 1. Although films 20A and 20B are as shown... Figure 3-1 and Figure 4 As shown, it has a multi-layered structure, but... Figures 6-1 to 6-5 For ease of explanation, only one layer is used to represent it. Figures 6-1 to 6-5 The shape of the resin substrate 10 and the configuration of the films 20A and 20B formed in multiple locations are merely examples and are not limited thereto.

[0121] like Figure 6-1 As shown, optical component 1 can be used as an optical window for light to pass through. Figure 6-1 In the optical component 1 shown, it can be located on two surfaces on one of the long sides of the resin substrate 10. Figure 6-1 A film 20A is disposed on the left and right sides of the resin substrate 10, on the two surfaces of the short side (the two surfaces of the short side of the resin substrate 10). Figure 6-1 A membrane 20B is set on the upper and lower surfaces.

[0122] like Figure 6-2 As shown, optical component 1 can also be used as a reflector to change the direction of light travel. Figure 6-2 In the optical component 1 shown, one surface on one side of the long side of the resin substrate 10 ( Figure 6-2 A multilayer film 20A is provided on the left side of the middle surface, and a mirror surface (on the other side of the long side of the resin substrate 10) is provided on the left side of the middle surface. Figure 6-2 The two surfaces of the middle right side and the short side of the resin substrate 10 (the middle right surface) ... Figure 6-2 A membrane 20B is provided on the upper and lower surfaces.

[0123] like Figure 6-3 As shown, optical component 1 can also be, for example, a prism with a tetrahedral shape. Figure 6-3 In the optical component 1 shown, two sides of one of the four sides of the resin substrate 10 ( Figure 6-3 A membrane 20B is disposed on the bottom surface of the membrane, and a multilayer membrane 20A is disposed on the other surfaces. Figure 6-3 (The surface other than the base). The shape of a prism can also be a polygon other than a tetrahedron.

[0124] like Figure 6-4 As shown, optical component 1 can further be used as a diffractive optical element (DOE) for forming the microstructure 14. Figure 6-4 In the optical component 1 shown, one surface on one side of the long side of the resin substrate 10 ( Figure 6-4 The left side of the middle surface and the other side of the surface with a fine structure 14 are formed. Figure 6-4 A multilayer film 20A is disposed on the right side surface of the resin substrate 10, on two surfaces of the short side ( Figure 6-4 A film 20B is disposed on both the top and bottom surfaces. Regarding the microstructure 14, there are no special restrictions as long as the structure can diffract the incident light; a general microstructure can be used.

[0125] like Figure 6-5 As shown, optical component 1 can also be used as a fluorescent element containing phosphor 15. Figure 6-5 In the optical component 1 shown, it can be connected with Figure 6-1 The optical component 1 shown is similarly provided with film 20A and film 20B.

[0126] In this embodiment, the resin substrate 10 is as follows: Figure 1 and Figure 2 The image shows the shape of a lens with concave sides, but it can also be an aspherical lens, a spherical lens, a single-sided concave lens, a double-sided convex lens, a single-sided convex lens, and other shapes.

[0127] In this embodiment, a first protective layer 21, a reflection-preventing layer 22, and a second protective layer 23 are provided on the resin substrate 10, but the reflection-preventing layer 22 may not be provided. Depending on the required reflection-preventing performance of the optical component 1, the reflection-preventing layer 22 may be omitted.

[0128] [Distance measuring device]

[0129] Next, a distance measuring device employing the optical component 1 of the above-described embodiment will be described. The distance measuring device includes: a light-projecting section having a light source that emits light; a detection section having a light-receiving element that receives reflected light projected from the light-projecting section and reflected by an object; and a calculation section for calculating the distance between the device and the object based on signals from the light-projecting section and the detection section, wherein at least one of the light-projecting section and the detection section has the aforementioned optical component.

[0130] The projection section can also be used as a projection device. In this case, the projection device includes a light-emitting element that emits light and the aforementioned optical component 1 through which the emitted light passes.

[0131] The aforementioned detection unit can also be used as a light receiving device. In this case, the light receiving device may include the aforementioned optical component 1 and a light-receiving element that receives light passing through the optical component 1.

[0132] The distance measuring device of the optical component 1 using the above-described embodiment can be equipped on vehicles such as automobiles and mobile bodies such as drones.

[0133] <First Method>

[0134] The following is for reference Figure 7 and Figure 8 This section details one method of using the optical component 1 described in the above embodiment for distance measuring devices. A distance measuring device is a device for measuring distance in the direction of an object, and can be used, for example, as a lidar device mounted on a car or similar vehicle.

[0135] Figure 7 This is a schematic diagram of a motor vehicle equipped with a LiDAR (Laser Imaging Detection and Ranging) device, which serves as an example of a ranging device. Figure 8 This is a schematic diagram of an example lidar device.

[0136] like Figure 7 As shown, the lidar device 100 is mounted on a car 101, for example, a "vehicle," and scans the target direction with light, receiving reflected light from an object 102 located in the target direction to determine the distance to the object 102. Besides vehicles, the lidar device 100 can also be mounted on mobile bodies such as drones.

[0137] like Figure 8 As shown, the lidar device 100 includes a light-projecting unit 110, a photodetector 120, and a ranging circuit 130.

[0138] The projection unit 110 includes a light source device 111, a collimating lens 112, a plane mirror 113, a movable device 114, a projection lens 115, and a control device 116. The light source device 111, the collimating lens 112, and the plane mirror 113 constitute an incident optical system, and the projection lens 115 constitutes a projection optical system. The collimating lens 112, the plane mirror 113, and the projection lens 115 may include the optical component 1 described in this embodiment.

[0139] The photodetector 120 includes a condenser lens 121, an imaging element 122, and a signal processing circuit 123. The condenser lens 121 may also include the optical component 1 described in this embodiment.

[0140] The laser emitted from the light source device 111 passes through an incident optical system consisting of a collimating lens 112 and a plane mirror 113, which serve as an optical system to make the diverging light approximately parallel. The laser is then scanned along one or two axes by a movable device 114 with a reflecting surface 114a. After passing through a projection lens 115, which serves as a projection optical system, the laser light is projected onto the object 102 in front of the device. A control device 116 controls the driving of the light source device 111 and the movable device 114. A photodetector 120 detects the reflected light from the object 102. Specifically, the reflected light passes through a condenser lens 121, which serves as a light-receiving optical system for incident light detection, and is received by an imaging element 122. The imaging element 122 outputs the detection signal to a signal processing circuit 123. The signal processing circuit 123 performs predefined processing on the input detection signal, including binarization and noise reduction, and outputs the result to a ranging circuit 130.

[0141] The ranging circuit 130 identifies the presence or absence of the object 102 based on the time difference between the time when the light source device 111 emits the laser and the time when the photodetector 120 receives the laser, or the phase difference of each pixel of the camera element 122 that receives the laser, and then calculates the distance information to the object 102.

[0142] The movable device 114 with reflective surface 114a is less prone to breakage than a multifaceted mirror. Because of its small size, it allows for the provision of a highly durable, compact radar device. This type of lidar device, installed in vehicles, aircraft, ships, robots, etc., can perform optical scanning over a specified area to determine the presence of obstacles and the distance to those obstacles. The lidar device 100 can be mounted not only at the upper front of the vehicle 101, but also on the side or rear.

[0143] The lidar device 100 has been described above as an example of a distance measuring device. However, any distance measuring device can be any device that uses a control device 116 to control a movable device 114 with a reflective surface 114a to perform light scanning and uses a photodetector to receive the reflected light to measure the distance to the object 102. It is not limited to the above-described embodiment.

[0144] The same applies to components of 3D scanners that output 3D data, such as those used for biometric authentication to identify objects by referencing records, security sensors to identify intruders by scanning the range of objects with light, and 3D scanners that calculate object information such as shape based on distance information obtained from light scanning.

[0145] By applying the optical elements of this embodiment to the distance measuring device, a distance measuring device with high long-term reliability can be provided.

[0146] <Second Method>

[0147] The following is for reference Figure 9 This section details other embodiments of the distance measuring device employing the optical component 1 described in the above-described embodiment. The distance measuring device includes a camera unit and an image analysis unit, and is used to measure the distance in the direction of an object. The camera unit is, for example, a light receiving device.

[0148] Figure 9 This is a schematic diagram of another example of a distance measuring device. (For example...) Figure 9 As shown, the distance measuring device 200 includes a camera unit 210 and an image analysis unit 220.

[0149] The imaging unit 210 is a stereo camera equipped with two identical imaging units 211 and 212, which are imaging means. The imaging units 211 and 212 may each include imaging lenses 211a and 212a, image sensors 211b and 212b with two-dimensionally arranged light-receiving elements, sensor base plates 211c and 212c including the image sensors 211b and 212b respectively, and signal processing circuits 211d and 212d that generate and output imaging image data by converting analog electrical signals (corresponding to the amount of light received by each light-receiving element on the image sensors 211b and 212b) output from the sensor base plates 211c and 212c into digital electrical signals. The imaging unit 210 outputs grayscale image data and parallax image data. The imaging lenses 211a and 212a of the imaging units 211 and 212 may also include the optical component 1 described in this embodiment.

[0150] The camera unit 210 includes a processing hardware unit 213 composed of an FPGA (Field-Programmable Gate Array) or similar components. This processing hardware unit 213 includes a disparity calculation unit 2131, which acts as a disparity image information generation device. It calculates the disparity value between corresponding image portions of the images captured by each camera unit 211 and 212, and obtains a disparity image from the grayscale image data output by the camera units 211 and 212.

[0151] The parallax value mentioned here refers to the value calculated by taking one of the video images captured by camera units 211 and 212 as a reference image and the other as a comparison image, and using the positional offset of the image portion of the comparison image relative to the image portion of the reference image corresponding to the same location within the camera area as the parallax value of that image portion. Using the principle of triangulation, the distance to the same location within the camera area corresponding to that image portion can be calculated from this parallax value.

[0152] The image analysis unit 220 includes an image processing base plate, etc., and has: a storage device 221 consisting of RAM and ROM that store luminance image information and parallax image information output by the camera unit 210; a CPU (Central Processing Unit) 222 that executes computer programs for object recognition processing and parallax calculation control, etc.; an information I / F (interface) 223; and a serial I / F 224.

[0153] The FPGA constituting the processing hardware unit 213 performs real-time processing on the image data, such as gamma correction, distortion correction (parallelization of left and right camera images), and disparity calculation based on block matching to generate disparity image information, which is then stored in the RAM of the image analysis unit 220. The CPU 222 of the image analysis unit 220 controls the image sensor controllers of the camera units 211 and 212 and the overall control of the image processing board. It also calls programs from ROM to execute detection processing for three-dimensional shapes such as road surfaces and detection processing for various objects (identified objects). It takes grayscale image data and disparity image data stored in RAM as input, performs various processing, and then outputs the processing results to the outside via data I / F 223 and serial I / F 224. The data output to the outside is used as input data for controlling various devices such as vehicles or robots equipped with distance measuring devices 200 (braking control, speed control, warning control, etc.).

[0154] The camera unit 210 and the image analysis unit 220 can also be configured as an integrated device, namely the distance measuring device 200.

[0155] Since the imaging unit 210 of this embodiment uses the optical component 1 of this embodiment as imaging lenses 211a and 212a, it can generate highly reliable image data over a long period of time. Furthermore, since the distance measuring device 200 of this embodiment uses the optical component 1 of this embodiment as imaging lenses 211a and 212a, it can obtain highly reliable image data over a long period of time and perform highly reliable distance measurement.

[0156] [Camera device]

[0157] exist Figure 9 The second embodiment shown describes a stereo camera equipped with an imaging unit 210 as a light receiving device. However, the optical components described in this embodiment can also be applied to imaging devices equipped with a camera lens and an image sensor. The imaging device is an example of a light receiving device. The following describes another embodiment of a light receiving device employing the light receiving device of the optical component 1 described above.

[0158] like Figure 10 As shown, the camera device 300 includes a camera lens 311a, an image sensor 311b with two-dimensionally arranged light-receiving elements, a sensor base plate 311c including the image sensor 311b, and a signal processing circuit 311d that generates and outputs camera image data that is converted into digital electrical signals by analog electrical signals (electrical signals corresponding to the amount of light received by each light-receiving element on the image sensor 311b) output from the sensor base plate 311c.

[0159] The image data output from the signal processing circuit 311d is output in the camera device 300.

[0160] The imaging lens 311a of the imaging unit 311 includes the optical component 1 described in this embodiment. The imaging device 300 may also include an optical window, a mirror, a prism, a diffractive optical element, etc., formed using the optical component 1 described in this embodiment.

[0161] Because the camera device 300 uses the optical component 1 described in this embodiment, it has a lens that is weather-resistant, lightweight, and not easily broken. Therefore, the camera device 300 can be well used as a camera mounted on an infrastructure monitoring and inspection drone such as a bridge pier, a camera for a surgical robot, a camera for an endoscope, a camera for a head-mounted display, etc., and can generate image data with high long-term reliability.

[0162] While the embodiments described above are examples, they are not limited to these embodiments. The present invention is not limited to them. These embodiments can be implemented in various other ways, and various combinations, omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are all included within the scope and spirit of the present invention, and also within the scope of the invention described in the patent claims and their equivalents.

[0163] In addition, the embodiments of the present invention are as follows, for example.

[0164] (1) An optical component having a multilayer film on the surface of a resin substrate, characterized in that the plurality of films include a first film and a second film, wherein the first film has a larger defect density than the second film and is formed on one side of the resin substrate, and the second film has a smaller defect density than the first film and is formed on the outer side of the first film.

[0165] (2) The optical component according to (1) is characterized in that the first film is disposed on a portion of the surface of the resin substrate, i.e., on a first region, and the second film is disposed on the first region and a second region where the first film is not formed.

[0166] (3) The optical component according to (2) is characterized in that the first region comprises a plurality of regions.

[0167] (4) The optical component according to any one of (1) to (3), characterized in that at least a portion of the film between the first film and the second film has a reflection-preventing layer.

[0168] (5) The optical component according to any one of (1) to (4), characterized in that the second film comprises Al2O3, HfO2, and SiO2. x SiN x and TiO x At least one of the following materials.

[0169] (6) The optical component according to any one of (1) to (5), characterized in that the thickness of the second film is 10 nm to 40 nm.

[0170] (7) The optical component according to any one of (1) to (6), characterized in that the second film contains Al2O3 and the refractive index of the second film relative to light at 550 nm is 1.630 or more and 1.670 or less.

[0171] (8) The optical component according to any one of (1) to (7), characterized in that the value of ((maximum film thickness - minimum film thickness) / (maximum film thickness + minimum film thickness) × 100) of the second film is 10% or less.

[0172] (9) The optical component according to any one of (1) to (8), characterized in that the second film is formed by atomic deposition.

[0173] (10) The optical component according to (2) is characterized in that the first region includes the effective region of the optical component.

[0174] (11) A light receiving device, characterized in that it comprises an optical component and a light receiving element as described in any one of (1) to (10), wherein the light receiving element receives light passing through or reflected by the optical component.

[0175] (12) A distance measuring device, comprising: a projection unit having a light source for emitting light; a detection unit having a light receiving element that receives reflected light from an object after being projected by the projection unit; and a calculation unit for calculating the distance between itself and the object based on signals from the projection unit and the detection unit, characterized in that at least one of the projection unit and the detection unit has an optical component as described in any one of (1) to (10).

[0176] (13) A mobile body, characterized in that it comprises the light receiving device described in (11).

[0177] (14) A mobile body, characterized in that it comprises the distance measuring device described in (12).

[0178] (15) A method for manufacturing an optical component, wherein the surface of a resin substrate of the optical component has a multilayer structure comprising a first film and a second film, the method being characterized by comprising: a first step of forming the first film on the surface of the resin substrate; and a second step of forming the second film having a defect density less than that of the first film after the first step.

[0179] Explanation of reference numerals in the attached figures

[0180] 1. Optical components

[0181] 10 Resin substrate

[0182] 20, 20A, 20B membranes

[0183] 21 First protective layer (first membrane)

[0184] 22 Anti-reflection layer

[0185] 23 Second protective layer (second membrane)

[0186] 100 LiDAR device (distance measurement device)

[0187] 200 Distance measuring device

[0188] 210 camera units

[0189] 220 Image Analysis Units

Claims

1. An optical component having a multilayer film structure on the surface of a resin substrate, characterized in that, The membrane includes a first membrane and a second membrane. The first membrane has a higher defect density than the second membrane and is formed on one side of the resin substrate. The second membrane has a lower defect density than the first membrane and is formed on the outer side of the first membrane. The defects are any one of point defects, line defects, and surface defects. The second membrane contains Al2O3 and has a refractive index of 1.630 or higher and 1.670 or lower relative to 550 nm light. The first membrane is disposed on a portion of the surface of the resin substrate, i.e., a first region. The second membrane is disposed on the first region and a second region where the first membrane is not formed. In the same region as or contained within the first region, the multilayer membrane has an anti-reflection layer between the first membrane and the second membrane.

2. The optical component according to claim 1, characterized in that, The first region includes multiple regions.

3. The optical component according to claim 1, characterized in that, The thickness of the second film is 10 nm to 40 nm.

4. The optical component according to claim 1, characterized in that, The value of ((maximum film thickness - minimum film thickness) / (maximum film thickness + minimum film thickness) × 100) of the second film is less than 10%.

5. The optical component according to claim 1, characterized in that, The second film is formed by atomic deposition.

6. The optical component according to claim 1, characterized in that, The first region includes the effective area of ​​the optical component.

7. A light receiving device, characterized in that, The device comprises the optical component and the light receiving element as described in claims 1 to 6, wherein the light receiving element receives light passing through or reflected by the optical component.

8. A distance measuring device, comprising: A projection section, which contains a light source that emits light; The detection unit includes a light-receiving element that receives reflected light from an object after being projected by the light-projecting unit; and The arithmetic unit is used to calculate the distance to the object based on signals from the projection unit and the detection unit. Its features are, At least one of the light-projecting part and the detection part is provided with an optical component as described in any one of claims 1 to 6.

9. A mobile body, characterized in that, It has the light receiving device as described in claim 7.

10. A mobile body, characterized in that, It possesses the distance measuring device as described in claim 8.

11. A method for manufacturing an optical component, wherein the surface of a resin substrate of the optical component has a multilayer structure comprising a first film and a second film, the manufacturing method being characterized by comprising: The first step is to form the first film on the surface of the resin substrate; and The second step is to form a second film with a defect density less than that of the first film after the first step, wherein the defect is any one of point defects, line defects and surface defects. The second film contains Al2O3, and its refractive index relative to 550 nm light is greater than 1.630 and less than 1.

670. The first film is disposed on a portion of the surface of the resin substrate, i.e., a first region, and the second film is disposed on the first region and a second region where the first film is not formed. In the same region as or contained in the first region, the multilayer structure film has an anti-reflection layer between the first film and the second film.

Images