Optical sensor device and mobile body

Abstract

The present invention prevents foreign matter from adhering to a light-transmitting section of an optical sensor device. A housing (130) that accommodates a light-emitting element (110) and a light-receiving element (120) therein has a light-transmitting section (131) through which light emitted by the light-emitting element (110) is transmitted to the outside and through which light coming from the outside to be received by the light-receiving element (120) is transmitted. At least a partial region (1311) of the outer surface of the light-transmitting section (131) has a plurality of protrusions (1312). The distance (D) between adjacent protrusions (1312) among the plurality of protrusions (1312) is less than or equal to the wavelength of the light emitted by the light-emitting element (110).

Description

Optical sensor device and mobile object

[0001] The present invention relates to an optical sensor device and a moving object.

[0002] An optical sensor device generally contains a light-emitting element that emits light and a light-receiving element that receives light within a housing. For this reason, the housing is provided with a light-transmitting portion that transmits light emitted by the light-emitting element and transmits external light that is received by the light-receiving element. If foreign matter such as water droplets, snow, ice, mud, or sand adheres to this light-transmitting portion, the foreign matter may cause reflection, scattering, or absorption of light, which may impair the function of the optical sensor device.

[0003] For example, the on-vehicle sensor device disclosed in Patent Document 1 has a sensing surface 5 a as a light-transmitting portion, and is equipped with a foreign matter adhesion prevention device 1 that injects gas from around the sensing surface 5 a to prevent foreign matter from adhering to the sensing surface 5 a.

[0004] JP 2015-170964 A

[0005] However, when the on-board sensor device disclosed in Patent Document 1 is provided with a foreign matter adhesion prevention device 1, the configuration of the optical sensor device becomes complex, and the manufacturing and maintenance costs of the optical sensor device increase.

[0006] An object of the present invention is to prevent foreign matter from adhering to the light transmitting portion of an optical sensor device.

[0007] In order to solve the above problem, an optical sensor device according to one embodiment of the present invention comprises a light-emitting element, a light-receiving element, and a housing that houses the light-emitting element and the light-receiving element, wherein the housing has a light-transmitting portion that transmits light emitted by the light-emitting element to the outside and transmits light from the outside that is received by the light-receiving element, and at least a portion of the outer surface of the light-transmitting portion has a plurality of convex portions, and the distance between adjacent convex portions among the plurality of convex portions is equal to or less than the wavelength of the light emitted by the light-emitting element.

[0008] An optical sensor device according to one embodiment of the present invention comprises a light receiving element and a housing that houses the light receiving element, the housing having a light-transmitting portion for transmitting light from the outside that is received by the light receiving element, at least a portion of the outer surface of the light-transmitting portion having a plurality of convex portions, and the distance between adjacent convex portions among the plurality of convex portions is equal to or less than the wavelength of the light received by the light receiving element.

[0009] A moving body according to one embodiment of the present invention is a moving body on which an optical sensor device is installed, and the partial region faces downward or obliquely downward.

[0010] According to the present invention, it is possible to prevent foreign matter from adhering to the light transmitting portion of the optical sensor device.

[0011] Fig. 1 is a cross-sectional view of an optical sensor device 100 according to an embodiment of the present invention. Fig. 2 is an enlarged view of an area A in Fig. 1. Fig. 3 is a diagram illustrating installation of the optical sensor device 100 on a moving body M. Fig. 4 is a diagram illustrating installation of the optical sensor device 100 on a moving body M. Fig. 5 is a diagram illustrating installation of the optical sensor device 100 on a moving body M.

[0012] <Optical Sensor Device 100> Fig. 1 is a cross-sectional view of an optical sensor device 100 according to one embodiment of the present invention. The optical sensor device 100 includes a light-emitting element 110, a light-receiving element 120, and a housing 130. The optical sensor device 100 is, for example, a sensor that measures an object by emitting light from the light-emitting element 110 and receiving light reflected by the object with the light-receiving element 120, such as a distance measurement sensor. The optical sensor device 100 is installed on, for example, a moving object M (e.g., a vehicle). The optical sensor device 100 may be a device (e.g., a camera) that does not include the light-emitting element 110. In this case, the optical sensor device 100 includes the light-receiving element 120 and a housing 130.

[0013] The light-emitting element 110 is an element that emits light. The light-emitting element 110 emits, for example, infrared light (particularly, near-infrared light (780 nm to 3 μm)). In other words, the emission wavelength range of the light-emitting element 110 includes infrared light (particularly, near-infrared light (780 nm to 3 μm)).

[0014] The light receiving element 120 is an element that receives light. The light receiving element 120 receives, for example, light in the wavelength range of light emitted by the light emitting element 110. In other words, the light receiving wavelength range of the light receiving element 120 includes the light emission wavelength range of the light emitting element 110. When the optical sensor device 100 is a device (e.g., a camera), the light receiving wavelength range of the light receiving element 120 includes, for example, visible light and / or infrared light.

[0015] 1, the housing 130 accommodates the light emitting element 110 and the light receiving element 120. The light emitting element 110 and the light receiving element 120 may be mounted on an electronic board 140, and the housing 130 may accommodate the electronic board 140 on which the light emitting element 110 and the light receiving element 120 are mounted.

[0016] The housing 130 has a light-transmitting portion 131. The light-transmitting portion 131 is a portion that transmits light emitted from the light-emitting element 110 to the outside and transmits light from the outside that is received by the light-receiving element 120. The transmittance of the light-transmitting portion 131 is 70% or more in the wavelength region of the light emitted by the light-emitting element 110 (or the light-receiving wavelength region of the light-receiving element 120).

[0017] In this embodiment, at least a partial region (first region 1311) of the outer surface of light transmitting portion 131 has a plurality of convex portions 1312, as shown in Fig. 2. Fig. 2 is an enlarged view of region A in Fig. 1. Region A is a region within first region 1311.

[0018] In this embodiment, the plurality of protrusions prevent adhesion of water droplets, snow, ice, mud, sand, etc. Therefore, in this embodiment, it is possible to prevent adhesion of foreign matter such as water droplets, snow, ice, mud, sand, etc. to the first region 1311 of the light transmitting portion 131.

[0019] Furthermore, the distance D between adjacent convex portions of the plurality of convex portions 1312 (i.e., the distance between the tops of adjacent convex portions 1312 of the plurality of convex portions 1312) is equal to or less than the wavelength of light emitted by the light-emitting element 110. For example, the distance D between adjacent convex portions of the plurality of convex portions 1312 is equal to or less than the wavelength of light with the longest wavelength of light emitted by the light-emitting element 110.

[0020] Therefore, in this embodiment, light is not scattered by the plurality of protrusions 1312 in the emission wavelength range of the light emitting element 110 or the light receiving wavelength range of the light receiving element 120. As a result, in this embodiment, it is possible to prevent foreign matter such as water droplets, snow, ice, mud, and sand from adhering to the optical sensor device 100 without affecting the measurement.

[0021] In this case, when the optical sensor device 100 is a device (e.g., a camera), the distance D between adjacent convex portions of the plurality of convex portions 1312 is equal to or less than the wavelength of light received by the light receiving element 120. For example, the distance D between adjacent convex portions of the plurality of convex portions 1312 is equal to or less than the wavelength of light with the maximum wavelength in the light receiving wavelength range of the light receiving element 120.

[0022] Soil is classified by grain size into clay (1 μm to 5 μm), silt (5 μm to 75 μm), fine sand (75 μm to 450 μm), coarse sand (450 μm to 2 mm), and gravel (2 mm or larger). Clay, the smallest grain size of soil, has a grain size of 1 μm to 5 μm. Therefore, it is advisable to set the wavelength of light emitted by the light-emitting element 110 to 1 μm or less. By doing so, the distance D between adjacent convex portions 1312 among the multiple convex portions 1312 becomes 1 μm or less. Therefore, by doing so, it is possible to prevent the smallest grain size clay from adhering without affecting the measurements of the optical sensor device 100.

[0023] The shape of the protrusions 1312 includes various shapes. For example, the shape of the protrusions 1312 is a mountain shape or a dome shape. The shape of the protrusions 1312 may be a shape in which the top portions of the protrusions 1312 extend in one direction (a wave shape). Furthermore, the shape of the protrusions 1312 may be a shape in which the top portions of the protrusions 1312 extend in two directions (a lattice shape).

[0024] The plurality of convex portions 1312 of the light transmitting portion 131 may be formed by processing the outer surface of the transparent resin substrate, or by attaching to the outer surface of the transparent resin substrate a sheet having the plurality of convex portions 1312. Note that the plurality of convex portions 1312 of the light transmitting portion 131 may also be formed by coating, printing, vapor deposition, or mechanical surface treatment (roughening).

[0025] Furthermore, the first region 1311 may preferably include a region through which the light emitted by the light-emitting element 110 passes and a region through which the light received by the light-receiving element passes. Generally, reflected light is more scattered than emitted light. Therefore, the first region 1311 may preferably be set based on the light-receiving area of ​​the light-receiving element 120. This makes it possible to prevent foreign matter such as water droplets, snow, ice, mud, and sand from adhering to the region through which the light emitted by the light-emitting element 110 passes and the region through which the light received by the light-receiving element passes.

[0026] <Installation on a Moving Body M> When the optical sensor device 100 is installed on a moving body M (e.g., a vehicle), it is preferable that the first region 1311 of the light-transmitting portion 131 faces downward as shown in Fig. 3 . Alternatively, the first region 1311 of the light-transmitting portion 131 may face diagonally downward as shown in Figs. 4 and 5 . This makes it possible to further prevent foreign matter from adhering to the first region 1311 of the light-transmitting portion 131. This improves the ability of foreign matter to fall off from the first region 1311 of the light-transmitting portion 131.

[0027] When the first region 1311 of the light-transmitting portion 131 faces diagonally downward, the optical sensor device 100 itself may be installed at an angle to the moving body M, as shown in FIG. 4, or only the light-transmitting portion 131 may be installed at an angle, as shown in FIG. 5.

[0028] The present invention has been described above in terms of preferred embodiments thereof. While the present invention has been described herein with reference to specific examples, various modifications and variations can be made to these examples without departing from the spirit and scope of the present invention as set forth in the claims.

[0029] REFERENCE SIGNS LIST 100 Optical sensor device 110 Light-emitting element 120 Light-receiving element 130 Housing 131 Light-transmitting portion 1311 First region 1312 Convex portion

Claims

1. An optical sensor device comprising: a light-emitting element; a light-receiving element; and a housing that houses the light-emitting element and the light-receiving element, wherein the housing has a light-transmitting portion that transmits light emitted by the light-emitting element to the outside and transmits light from the outside that is received by the light-receiving element, at least a partial area of ​​the outer surface of the light-transmitting portion has a plurality of convex portions, and the distance between adjacent convex portions of the plurality of convex portions is equal to or less than the wavelength of the light emitted by the light-emitting element.

2. The optical sensor device according to claim 1, wherein the light emitted by said light-emitting element is infrared light.

3. The optical sensor device according to claim 2, wherein the light emitted by the light-emitting element is near-infrared light.

4. The optical sensor device according to claim 3, wherein the wavelength of light emitted by said light emitting element is 1 μm or less.

5. The optical sensor device according to claim 1, wherein the transmittance of said light transmitting portion is 70% or more in the wavelength region of light emitted by said light emitting element.

6. An optical sensor device according to claim 1, wherein the area of ​​said partial region is set to include an area through which light emitted by said light-emitting element passes and an area through which light received by said light-receiving element passes.

7. The optical sensor device according to claim 6, wherein the area of ​​the partial region is set based on the light-receiving area of ​​the light-receiving element.

8. An optical sensor device comprising: a light receiving element; and a housing that houses the light receiving element, wherein the housing has a light-transmitting portion for transmitting external light received by the light receiving element, at least a partial area of ​​the outer surface of the light-transmitting portion has a plurality of convex portions, and the distance between adjacent convex portions of the plurality of convex portions is equal to or less than the wavelength of the light received by the light receiving element.

9. A moving object on which the optical sensor device according to any one of claims 1 to 8 is installed, wherein the partial area faces obliquely downward.

Images