JP6904392B2 - Cover for near infrared sensor - Google Patents

Description

The present invention relates to a cover for a near-infrared sensor arranged in front of the direction of transmission of near-infrared rays transmitted from the near-infrared sensor.

In the field of vehicles, the near-infrared sensor transmits near-infrared rays toward the front of the vehicle and receives the near-infrared rays reflected by hitting the front obstacles including the preceding vehicle, pedestrians, etc. Development of a technique for detecting relative velocity is in progress (see, for example, Patent Document 1).

JP 2015-209112

However, if the near-infrared sensor is attached to the vehicle in a bare state, the near-infrared sensor can be seen directly from the front of the vehicle. Due to this, not only the near-infrared sensor itself but also the appearance around the near-infrared sensor is impaired in the vehicle, and there is room for improvement in terms of design.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a cover for a near-infrared sensor capable of improving design while ensuring a detection function of the near-infrared sensor. There is.

The near-infrared sensor cover that solves the above problems is a plate-shaped near-infrared sensor cover that is arranged in front of the near-infrared ray transmitting direction transmitted from the near-infrared sensor in a vehicle, and the main part in the thickness direction is The cover body is composed of a cover body, and the cover body has a front surface on the side far from the near-infrared sensor and a back surface on the side close to the near-infrared sensor, and at least one of the front surface and the back surface of the cover body. The reflection suppression layer is laminated, and the light transmission rate of near infrared rays in the cover body in which the reflection suppression layer is laminated is 80% or more, and the light transmission rate of visible light is 70% or less.

In the cover for the near-infrared sensor, a storage case for accommodating the near-infrared sensor is attached with its wall portion close to the back surface of the cover body, and the reflection suppression layer is formed on the back surface and the wall portion. It is preferable that they are laminated between and.

In the near-infrared sensor cover, it is preferable that the entire cover body is formed in a shape in which the thickness of the cover body gradually changes in the direction along the front surface and the back surface.

In the near-infrared sensor cover, the front surface is formed of a flat surface, and a part of the back surface is inclined with respect to the front surface so that the distance from the front surface gradually changes in the direction along the same surface. And the second plane whose distance from the surface gradually changes with respect to the direction along the same surface by inclining the surface so as to have the opposite relationship to the first plane. It is preferable that the first plane and the second plane intersect in a sharp state.

According to the cover for the near-infrared sensor, the design can be improved while ensuring the detection function of the near-infrared sensor.

A side sectional view showing a cover for a near-infrared sensor according to the first embodiment together with a near-infrared sensor. A side sectional view showing a cover for a near-infrared sensor according to a second embodiment together with a near-infrared sensor. A partial side sectional view of a cover for a near infrared sensor according to a third embodiment. A side sectional view showing a cover for a near-infrared sensor according to a fourth embodiment together with a near-infrared sensor. A side sectional view showing a cover for a near-infrared sensor according to a fifth embodiment together with a near-infrared sensor. A side sectional view showing a cover for a near-infrared sensor according to a sixth embodiment together with a storage case having an antireflection layer formed therein and a near-infrared sensor. A side sectional view showing a cover for a near-infrared sensor according to a seventh embodiment together with a near-infrared sensor. A side sectional view showing a cover for a near-infrared sensor according to an eighth embodiment together with a near-infrared sensor.

(First Embodiment)
Hereinafter, the first embodiment of the cover for the near infrared sensor will be described with reference to FIG.
Near-infrared sensors 11 are attached to both sides of the front portion of the vehicle 10 in the vehicle width direction. Applicable mounting locations include, for example, both sides of the front lower grille in the vehicle width direction, both sides of the front bumper in the vehicle width direction, and the vicinity of each of the pair of fog lamps.

Each near-infrared sensor 11 is a component that constitutes a part of the near-infrared radar device, transmits the near-infrared IR1 toward the front of the vehicle 10, and is reflected by hitting a front obstacle including a preceding vehicle, a pedestrian, and the like. By receiving the near-infrared IR2, the distance to the front obstacle and the relative velocity are detected. The detection result is used for collision damage mitigation control, false start suppression control, and the like. Collision damage mitigation control is a control for reducing damage caused by a collision by operating a brake when it is determined that there is a possibility of a collision between the vehicle 10 and a front obstacle. The erroneous start suppression control is a control for suppressing the output of the engine and suppressing the sudden start of the vehicle 10 when the accelerator pedal is depressed more than a certain amount in a situation where there is an obstacle in front while the vehicle 10 is stopped. Is.

Infrared rays are a kind of electromagnetic waves and have a wavelength longer than the wavelength of visible light (0.36 μm to 0.83 μm). Near-infrared IR1 and IR2 have the shortest wavelength (0.83 μm to 3 μm) among infrared rays.

As a device having a function similar to that of the near-infrared radar device, there is a millimeter-wave radar device that detects the distance between the vehicle and the preceding vehicle traveling in front of the vehicle 10. The millimeter wave radar device emits millimeter waves toward a predetermined angle range in front of the vehicle 10, and detects the inter-vehicle distance and relative speed with the preceding vehicle from the time difference between the transmitted wave and the received wave, the intensity of the received wave, and the like. To do.

The near-infrared sensor 11 in each near-infrared radar device emits a near-infrared IR1 toward a wider angle range than the millimeter-wave radar device. Further, the near-infrared sensor 11 detects an obstacle in front of the millimeter-wave radar at a distance closer than that of the millimeter-wave radar.

In the vehicle 10, a plate-shaped cover for the near-infrared sensor (hereinafter referred to as "cover 20A") is arranged in the vicinity of the front in the transmission direction of the near-infrared IR1 transmitted from each near-infrared sensor 11. It is attached to a strength member such as a radiator grill and a lean hosement in the vehicle 10. The cover 20A for each near-infrared sensor 11 has a common configuration.

At least the main part of each cover 20A in the thickness direction is composed of the cover main body 21. In the first embodiment, the entire cover 20A in the thickness direction is composed of the cover main body 21. Each cover body 21 is formed of a transparent resin material, for example, a material-coated resin material containing PC (polycarbonate), PMMA (polymethylmethacrylate), COP (cycloolefin polymer) or the like as main components. The material-coated resin material is a material in which the resin itself is colored by mixing a coloring material such as a pigment with the resin material, or by mixing a bright material with the coloring material with the resin material. The entire cover body 21 configured in this way is colored and translucent. The light transmittance of the near infrared rays IR1 and IR2 in each cover body 21 is 80% or more, and the light transmittance of visible light is 70% or less.

Each cover body 21 has a front surface 22 on the side far from the near infrared sensor 11 and a back surface 23 on the side close to the near infrared sensor 11. The entire cover body 21 is formed in a shape in which the thickness T, which is the distance between the front surface 22 and the back surface 23, gradually changes in the direction along the front surface 22 and the back surface 23 (approximately the vertical direction in FIG. 1). .. In the first embodiment, the front surface 22 is formed of a flat surface, and the back surface 23 is formed of a concave curved surface. With this configuration, the thickness T of each cover main body 21 is minimized at the intermediate portion in the vertical direction, and gradually increases as the distance from the intermediate portion is upward and downward.

Next, the operation and effect of the first embodiment configured as described above will be described.
Each cover 20A that is colored and translucent and has a visible light transmittance of 70% or less is located in front of the near-infrared IR1 transmitted from the near-infrared sensor 11 in the transmission direction. Demonstrate the function of hiding. In the first embodiment, this function is exerted by the cover main body 21 constituting each cover 20A.

Therefore, when each cover 20A is viewed from the front of the vehicle 10, the near-infrared sensor 11 located behind the colored translucent cover 20A (cover body 21) is difficult to see. Therefore, as compared with the case where each cover 20A is not used and each near-infrared sensor 11 is attached to the vehicle 10 in a bare state and these near-infrared sensors 11 can be seen directly, the appearance is improved and the design is improved. Can be improved.

Further, in each of the colored translucent cover main bodies 21, the color depth differs depending on the thickness thereof. The portion having a large thickness T has a darker color than the portion having a small thickness T. Therefore, the design of the cover main body 21 is rich in variation as compared with the case where the thickness T of each cover main body 21 is uniform and the color depth is constant at any part of the cover main body 21.

Moreover, since the thickness T of each cover body 21 gradually changes in the direction along the front surface 22 and the back surface 23 of the cover body 21, the color depth is continuous in the direction along the front surface 22 and the back surface 23. It changes with the gradation. Therefore, the change in shade becomes more natural than in the case where the shade of color changes abruptly.

Further, each cover 20A covers each near-infrared sensor 11 from the front of the vehicle 10, so that the near-infrared sensor 11 is protected. This protection prevents the near-infrared sensor 11 from being scratched. In addition, deterioration or deterioration of each near-infrared sensor 11 due to sunlight, wind and rain, temperature change, or the like is suppressed.

By the way, when the near-infrared IR1 is transmitted from each near-infrared sensor 11, the near-infrared IR1 passes through the cover main body 21 of each cover 20A. This near-infrared IR1 hits a front obstacle and is reflected. The reflected near-infrared IR2 passes through the cover body 21 again and is received by the near-infrared sensor 11. Since the light transmittance of the near-infrared IR1 and IR2 in each cover body 21 is 80% or more, these cover bodies 21 are unlikely to interfere with the transmission and reflection of the near-infrared IR1 and IR2. Of the near-infrared IR1 and IR2, the amount attenuated by each cover body 21 can be kept within an allowable range. Therefore, each near-infrared sensor 11 can appropriately exert a function of detecting the distance and the relative speed between the vehicle 10 and the obstacle in front.

(Second Embodiment)
Next, a second embodiment of the cover for the near infrared sensor will be described with reference to FIG.
In the second embodiment, the main part of each near-infrared sensor cover (hereinafter referred to as “cover 20B”) is composed of the cover main body 24. Each cover body 24 is made of a transparent resin material such as PC, PMMA, and COP, and is colorless and transparent. In this respect, the second embodiment is different from the first embodiment in which each cover main body 21 is formed of a material-coated resin material and is colored and translucent.

Each cover body 24 has a front surface 25 on the side far from each near-infrared sensor 11 and a back surface 26 on the side close to the near-infrared sensor 11. On the back surface 26 of each cover main body 24, a colored translucent layer 27 colored so as to have a uniform density is laminated at any position along the back surface 26. The colored translucent layer 27 is formed by printing on the back surface 26 or by attaching a film to the back surface 26.

The light transmittance of the near infrared rays IR1 and IR2 in each cover 20B formed by laminating the colored semitransparent layer 27 on each cover body 24 is 80% or more, and the light transmittance of visible light is 70% or less. is there.

The configuration other than the above is the same as that of the first embodiment. Therefore, the same elements as those described in the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.
Therefore, according to the second embodiment, the cover main body 24 forming the main portion in the thickness direction of each cover 20B and the colored translucent layer 27 laminated on the back surface 26 of the cover main body 24 have a function of hiding each near infrared sensor 11. And makes the near-infrared sensor 11 difficult to see, so that the appearance is improved.

Further, the cover body 24 and the colored translucent layer 27 are less likely to interfere with the transmission of the near-infrared IR1 transmitted from the near-infrared sensor 11 and the near-infrared IR2 reflected by hitting a front obstacle. Therefore, each near-infrared sensor 11 tends to exert a detection function.

However, although the thickness T of each cover main body 24 gradually changes in the direction along the front surface 25 and the back surface 26 of the cover main body 24, each cover main body 24 is colorless and transparent at any place. The color of each cover 20B is determined exclusively by the colored translucid layer 27 having a uniform density everywhere. Therefore, unlike the first embodiment, the second embodiment is different from the first embodiment, and it is difficult to obtain the effect of making the color depth different depending on the thickness T of each cover main body 24.

(Third Embodiment)
Next, a third embodiment of the cover for the near-infrared sensor will be described with reference to FIG.
In the third embodiment, each near-infrared sensor cover (hereinafter referred to as "cover 20C") is composed entirely of a colored translucent cover body 28 in the thickness direction. Each cover body 28 is formed of a flat surface and has a front surface 29 on the side far from each near-infrared sensor 11 and a back surface 30 on the side close to the near-infrared sensor 11.

In the third embodiment, a second plane in which a part of the back surface 30 is inclined so as to have an opposite relationship between the first plane 31 which is inclined with respect to the front surface 29 and the first plane 31 which is inclined with respect to the front surface 29. It is composed of a plane 32 and the like. More specifically, the first flat surface 31 is formed in a state of being inclined with respect to the surface 29 so that the distance (thickness T) from the surface 29 gradually increases toward the lower side. The second plane 32 is formed in a state of being inclined with respect to the surface 29 in a direction opposite to that of the first plane 31 so that the distance (thickness T) from the surface 29 gradually decreases toward the lower side. There is. Due to the first plane 31 and the second plane 32, a protrusion 33 that protrudes rearward and has a sharp rear end is formed in a part of the cover main body 28. In other words, at the rear end of the protrusion 33, the first plane 31 and the second plane 32 intersect in a sharp state.

The angle formed by the surface 29 of the first plane 31 may be the same as or different from the angle formed by the surface 29 of the second plane 32.
The light transmittance of the near-infrared IR1 and IR2 in each cover 20C composed of a part of the back surface 30 of the cover body 28 by the first plane 31 and the second plane 32 is 80% or more. Moreover, the light transmittance of visible light is 70% or less.

The configuration other than the above is the same as that of the first embodiment. Therefore, the same elements as those described in the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.
Therefore, according to the third embodiment, as in the first embodiment, the near-infrared sensor 11 behind the cover main body 28 is colored and translucent and has a light transmittance of 70% or less of visible light. It is possible to make it difficult to see and improve the appearance and improve the design. Further, each cover body 28 having a light transmittance of 80% or more for the near-infrared IR1 and IR2 allows the near-infrared sensor 11 to properly exhibit the detection function.

In addition, according to the third embodiment, a part of the visible light incident on the cover main body 28 from the front surface 29 side is reflected by the back surface 30, and the first plane 31 and the second plane 32. The mode of reflection is different. Therefore, when each cover 20C is viewed from the front of the vehicle 10, the appearance of the first plane 31 and the second plane 32 is different, and the design of the cover 20C is rich in variation.

In particular, the portion where the first plane 31 and the second plane 32 intersect in a sharp state (the portion surrounded by the frame of the alternate long and short dash line in FIG. 3) looks like a line. Therefore, by devising the position, extending direction, length, etc. of this portion, the design of the cover 20C can be made rich in variety, such as expressing a grid-like pattern.

(Fourth Embodiment)
Next, a fourth embodiment of the cover for the near-infrared sensor will be described with reference to FIG.
Each near-infrared sensor cover of the fourth embodiment (hereinafter simply referred to as "cover 20D") is laminated on the surface 22 of the colored translucent cover main body 21 in addition to the configuration of the first embodiment, and generates heat when energized. It includes a heating layer 34.

As the heating layer 34, a layer that does not easily transmit visible light and easily transmits near infrared rays IR1 and IR2 is used. For example, a transparent conductive film made of a metal oxide-based conductive material such as ITO (indium tin oxide) or tin oxide is formed on a polymer base material such as a film-like PET (polyethylene terephthalate) or PEN (polyethylene naphthalate). A film formed by sputtering or the like is used as the heating layer 34. It is desirable that the heating layer 34 having such a structure has a uniform temperature distribution in the direction along the surface 22 when heat is generated.

The light transmittance of the near infrared rays IR1 and IR2 in each cover 20D formed by laminating the heating layer 34 on the surface 22 of the cover main body 21 is 80% or more, and the light transmittance of visible light is 70% or less. is there.

The configuration other than the above is the same as that of the first embodiment. Therefore, the same elements as those described in the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.
Therefore, according to the fourth embodiment, the same actions and effects as those of the first embodiment can be obtained. In addition, according to the fourth embodiment, the near-infrared IR1 transmitted from each near-infrared sensor 11 and the near-infrared IR2 reflected by hitting a front obstacle pass through each cover 20D. At this time, the transparent heating layer 34 does not easily interfere with the transmission of the near infrared IR1 and IR2.

Further, when it snows, the transparent conductive film of the heating layer 34 is energized to generate heat, so that the snow can be suppressed from adhering to the surface of each cover 20D and the adhering snow can be melted.

In particular, in the fourth embodiment, since the heating layer 34 is located at the foremost part of each cover 20D, the heat generated by the heating layer 34 is easily transferred to the snow adhering to the surface of each cover 20D. Therefore, the attached snow can be efficiently melted by the heat of the heating layer 34.

(Fifth Embodiment)
Next, a fifth embodiment of the cover for the near infrared sensor will be described with reference to FIG.
The cover for each near-infrared sensor (hereinafter referred to as "cover 20E") of the fifth embodiment is a reflection suppression layer formed on the back surface 23 of each cover main body 21 and made of a transparent thin film in addition to the configuration of the first embodiment. It has 35. For each reflection suppression layer 35, a material having a refractive index lower than that of the forming material (PC, PMMA, COP, etc.) of each cover body 21, for example, magnesium fluoride, etc. is used, and vacuum deposition, sputtering, WET coating, etc. are performed. It is formed by being done. The thickness of each reflection suppression layer 35 is set so that the near-infrared IR1A reflected on the back surface 23 of each cover body 21 and the near-infrared IR1B reflected on the back surface of the reflection suppression layer 35 are in opposite phases to each other. ing.

The light transmittance of the near infrared rays IR1 and IR2 in each cover 20E formed by laminating the reflection suppression layer 35 on the back surface 23 of each cover body 21 is 80% or more, and the light transmittance of visible light is 70%. It is as follows.

The configuration other than the above is the same as that of the first embodiment. Therefore, the same elements as those described in the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.
Therefore, according to the fifth embodiment, the same actions and effects as those of the first embodiment can be obtained. In addition, according to the fifth embodiment, most of the near-infrared IR1 transmitted from each near-infrared sensor 11 transmits through each cover 20E, but some of them pass through the back surface 23 of each cover body 21 and reflection suppression. Each is reflected on the back surface of the layer 35. At this time, the near-infrared IR1A reflected on the back surface 23 of the cover main body 21 passes through the reflection suppression layer 35, causing a phase shift from the near-infrared IR1B reflected on the back surface of the reflection suppression layer 35. The near-infrared IR1A and the near-infrared IR1B are out of phase with each other, and both near-infrared IR1A and IR1B interfere with each other and cancel each other out. In this way, the reflection of the near infrared IR1 on the back surface side of each cover 20E is reduced. It is possible to suppress a decrease (loss) in the amount of near-infrared IR1 transmitted through each cover 20E due to reflection. With respect to the near-infrared IR1 transmitted from each near-infrared sensor 11, the degree of the near-infrared IR2 returning to the near-infrared sensor 11 can be increased, and each near-infrared sensor 11 can appropriately exert the detection function.

(Sixth Embodiment)
Next, a sixth embodiment of the cover for the near infrared sensor will be described with reference to FIG.
In the sixth embodiment, a storage case 36 for accommodating each near-infrared sensor 11 is used. Each storage case 36 includes a tubular wall portion 37, a bottom wall portion 38, and a flange wall portion 39. The tubular wall portion 37 has a tubular shape extending in the front-rear direction, and surrounds each near-infrared sensor 11 from the top, bottom, left, and right. The bottom wall portion 38 is provided at the rear end portion of the tubular wall portion 37, and closes the tubular wall portion 37 from the rear side. The flange wall portion 39 is formed around the front end portion of the tubular wall portion 37.

As the cover for each near-infrared sensor, a cover having the same configuration as the cover 20A in the first embodiment is used.
Each of the storage cases 36 is attached to the vehicle 10 in a state where the flange wall portion 39 is brought close to the back surface of each cover 20A (the back surface 23 of the cover main body 21).

Similar to the reflection suppression layer 35 in the fifth embodiment, the reflection suppression made of a transparent thin film is formed on the inner wall surface of each storage case 36 in the region where the near infrared IR1 from each near infrared sensor 11 is irradiated. Layer 41 is formed.

The thickness of the reflection suppression layer 41 is set so that the near-infrared IR1 reflected by the inner wall surface of each storage case 36 and the near-infrared IR1 reflected by the reflection suppression layer 41 are in opposite phases to each other.

The configuration other than the above is the same as that of the first embodiment. Therefore, the same elements as those described in the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.
Therefore, according to the sixth embodiment, the same actions and effects as those of the first embodiment can be obtained. In addition, according to the sixth embodiment, a part of the near-infrared IR1 transmitted from each near-infrared sensor 11 is also applied to the inner wall surface of each storage case 36, mainly the tubular wall portion 37 and the flange wall portion 39. Be irradiated. Here, if no measures are taken for the irradiated portion, the near-infrared IR1 is reflected by the tubular wall portion 37, the flange wall portion 39, and the like. If the reflected near-infrared IR1 is mixed with the near-infrared IR2 reflected by the front obstacle and received by each near-infrared sensor 11, the distance to the front obstacle and the relative velocity may be erroneously detected. is there.

In this regard, in the sixth embodiment, a part of the near-infrared IR1 transmitted from each near-infrared sensor 11 is reflected by the inner wall surface of the housing case 36 and the reflection suppression layer 41, respectively. At this time, the near-infrared IR1 reflected on the inner wall surface of the accommodation case 36 passes through the reflection suppression layer 41, causing a phase shift from the near-infrared IR1 reflected by the reflection suppression layer 41. The near-infrared IR1 reflected on the inner wall surface of the storage case 36 and the near-infrared IR1 reflected by the reflection suppression layer 41 are in opposite phases to each other, and both near-infrared IR1s interfere with each other and cancel each other out. In this way, the reflection of the near infrared IR1 in the housing case 36 is reduced. Due to the reflection of the near-infrared IR1 in the housing case 36, it is possible to prevent each near-infrared sensor 11 from erroneously detecting the distance to the front obstacle and the relative speed.

Further, it is possible to suppress a decrease (loss) of the amount of near-infrared IR1 transmitted through each storage case 36 due to reflection. With respect to the near-infrared IR1 transmitted from each near-infrared sensor 11, the degree of the near-infrared IR2 returning to the near-infrared sensor 11 can be increased, and each near-infrared sensor 11 can appropriately exert the detection function.

(7th Embodiment)
Next, a seventh embodiment of the cover for the near infrared sensor will be described with reference to FIG. 7.
In each cover for near-infrared sensor of the seventh embodiment (hereinafter referred to as "cover 20F"), in addition to the configuration of the first embodiment, an antifouling layer 42 is formed on the front surface 22 of each cover main body 21 and the back surface 23 is protected. A cloudy layer 43 is formed. The antifouling layer 42 is composed of, for example, a film formed by using a fluorine compound or the like. The anti-fog layer 43 is formed, for example, by applying an anti-fog agent to the back surface 23 of the cover main body 21.

The light transmittance of the near infrared rays IR1 and IR2 in each cover 20F formed by laminating the antifouling layer 42 and the antifogging layer 43 on each cover body 21 is 80% or more, and the light transmittance of visible light is 70. % Or less.

The configuration other than the above is the same as that of the first embodiment. Therefore, the same elements as those described in the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.
Therefore, according to the seventh embodiment, the same actions and effects as those of the first embodiment can be obtained. In addition, according to the seventh embodiment, dirt components such as raindrops and mud are less likely to adhere to the surface of the cover 20F. Further, even if a dirt component adheres, it can be easily removed to clean the surface of the cover 20F.

Further, according to the seventh embodiment, even if each cover 20F cools and falls below the dew point, it is possible to prevent the water vapor in the air from condensing and dew condensation on the back surface of the cover 20F.
Therefore, it is possible to prevent the detection function of each near-infrared sensor 11 from being impaired and the detection accuracy from being lowered due to the above-mentioned dirt component adhering to the front surface of each cover 20F or dew condensation on the back surface. Can be done.

(8th Embodiment)
Next, the eighth embodiment of the cover for the near infrared sensor will be described with reference to FIG.
In each cover for near-infrared sensor of the eighth embodiment (hereinafter referred to as "cover 20G"), each cover main body 21 of the first embodiment has a colored translucent or transparent front main body 44 constituting the front portion thereof. It is divided into a colored translucent or transparent rear main body 45 that constitutes the rear portion of the cover main body 21. However, at least one of the front main body 44 and the rear main body 45 is colored and translucent. A liquid crystal type light control film 46 containing liquid crystal molecules in a transparent polymer is arranged between the front main body portion 44 and the rear main body portion 45.

When a voltage is applied to the light control film 46, the liquid crystal molecules in the transparent polymer are regularly arranged in the direction in which the light passes, so that the light can easily pass through (a substantially transparent state), and the voltage application is stopped. Then, the liquid crystal molecules are arranged irregularly and it becomes difficult for light to pass through.

Utilizing these characteristics of the light control film 46, in the eighth embodiment, the voltage is applied to each light control film 46 when the vehicle 10 is running, and the voltage application is stopped when the vehicle 10 is stopped. There is. Switching between applying a voltage to each light control film 46 and stopping the application is performed, for example, by an electronic control device (not shown) mounted on the vehicle 10 based on the vehicle speed or the like.

The light transmittance of the near infrared rays IR1 and IR2 in each cover 20G in which the light control film 46 is arranged between the front main body portion 44 and the rear main body portion 45 is 80% or more, and the light transmittance of visible light is transmitted. The rate is 70% or less. However, for visible light, it is a value when voltage application is stopped.

The configuration other than the above is the same as that of the first embodiment. Therefore, the same elements as those described in the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.
Therefore, according to the eighth embodiment, the same actions and effects as those of the first embodiment can be obtained. In addition, according to the eighth embodiment, when the vehicle 10 is traveling, a voltage is applied to each dimming film 46 by an electronic control device, so that the synchronized light film 46 is in a state where light can easily pass through. Therefore, each dimming film 46 is unlikely to interfere with the transmission of near-infrared rays IR1 and IR2 transmitted from each near-infrared sensor 11 or reflected by a front obstacle. Therefore, each near-infrared sensor 11 can exert its detection function.

On the other hand, when the vehicle 10 is stopped, the electronic control device stops the application of the voltage to each dimming film 46, which makes it difficult for the synchronized light film 46 to pass light. Therefore, the function of each cover 20G hiding the near-infrared sensor 11 can be enhanced by the light control film 46. From the front of the vehicle 10, each near-infrared sensor 11 becomes even more difficult to see.

The above embodiment can also be implemented as a modified example in which the above is modified as follows.
<About the first embodiment>
-The first embodiment may be implemented by combining two or more of the contents of the fourth to eighth embodiments.

<About the second embodiment>
The colored translucent layer 27 may be laminated on the front surface 25 instead of the back surface 26 of each cover main body 24. Further, the colored translucent layer 27 may be laminated on both the front surface 25 and the back surface 26 of each cover main body 24.

-The second embodiment may be implemented by combining at least one content of the third to eighth embodiments. When the third embodiment is combined, a part of the back surface 26 of each cover main body 24 is composed of a first plane and a second plane.

<About the third embodiment>
-Instead of the protrusion 33 composed of the first plane 31 and the second plane 32 in FIG. 3, as shown by the alternate long and short dash line in FIG. 3, a recess recessed forward is provided in a part of the cover main body 28. It may be formed. In this case, the first flat surface 31 is formed in a state of being inclined with respect to the surface 29 so that the distance (thickness T) from the surface 29 gradually decreases toward the lower side. The second plane 32 is formed in a state of being inclined with respect to the surface 29 in a direction opposite to that of the first plane 31 so that the distance (thickness T) from the surface 29 gradually increases toward the lower side. .. The first plane 31 and the second plane 32 intersect in a pointed state at the deepest part of the recess.

The angle formed by the surface 29 of the first plane 31 may be the same as or different from the angle formed by the surface 29 of the second plane 32.
-The third embodiment may be implemented by combining at least one content of the fourth to eighth embodiments.

<About the fourth embodiment>
Each heating layer 34 may be laminated on the back surface 23 instead of the front surface 22 of each cover body 21. However, since the heating layer 34 is moved away from the surface of each cover 20D, the heat generated by the heating layer 34 is less likely to be transferred to the snow adhering to the surface of the cover 20D.

-As each heating layer 34, one provided with a resin sheet and a linear heater formed on the resin sheet may be used. As the resin sheet, for example, a sheet formed of a transparent resin material such as PC is used. Further, as the linear heater, for example, a heater formed by printing a nichrome wire, a carbon heating element, a silver paste or the like is used.

It is desirable that this heater is provided in a portion of the cover 20D outside the transmission and reflected near-infrared IR1 and IR2 transmission regions. By doing so, it is possible to prevent the heater from interfering with the transmission of the near infrared IR1 and IR2.

When the heater generates heat, the heat is also transmitted to the transmission region surrounded by the heater in each cover 20D. Therefore, even if snow adheres to each cover 20D, the snow can be melted by the heat transferred from the heater.

The heater may be arranged alone, not as a part of the resin sheet.
<About the fifth embodiment>
-Each reflection suppression layer 35 may be formed on the front surface 22 instead of the back surface 23 of each cover main body 21. By doing so, the reflection of the near infrared IR2 on the surface of each cover 20E is suppressed. The amount of near-infrared IR2 that passes through the cover 20E and returns to the near-infrared sensor 11 increases. Therefore, each near-infrared sensor 11 can exert the detection function more appropriately.

Further, each reflection suppression layer 35 may be formed on both the front surface 22 and the back surface 23 of each cover main body 21. By doing so, it is possible to suppress both the reflections of the near infrared rays IR1 and IR2 on the front surface and the back surface of each cover 20E.

<Matters common to the 5th and 6th embodiments>
-As the reflection suppression layers 35 and 41, those in which a plurality of thin films are laminated may be adopted. In this case, as the plurality of thin films, those having different refractive indexes and thicknesses may be used. In this way, the phases of the near-infrared IR1 and IR2 reflected by each thin film can be made different. It is possible to reduce the reflection of near infrared IR1 and IR2 for a wide range of wavelengths.

<About the 7th embodiment>
-In each cover 20F, one of the antifouling layer 42 and the antifogging layer 43 may be omitted.
A water-repellent layer, a hydrophilic layer, a photocatalyst layer, or the like may be formed on the surface 22 of each cover body 21 instead of the antifouling layer 42. By doing so, it is possible to prevent water droplets, mud, etc. from adhering to the surface of each cover 20F.

For example, the water-repellent layer is composed of an organic coating film, a silicone film, or the like. The water-repellent layer repels water adhering to the surface of the cover 20F and makes the cover 20F less likely to get wet, thereby suppressing the formation of a water film on the surface of each cover 20F.

Further, when the hydrophilic layer is provided, the condensed water can be spread in a film shape to be washed away.
Further, when the photocatalyst layer is provided, the contact angle of water can be brought close to zero by making it superhydrophilic, and the condensation of water droplets can be suppressed.

<About the eighth embodiment>
-As each light control film 46, a film different from the liquid crystal system described above, for example, an SPD (Suspended Particle Device) system, an electrochromic system, a thermochromic system, or the like may be adopted.

<Matters common to the first, second, fourth to eighth embodiments>
-As the cover bodies 21 and 24, those having a uniform thickness T may be used.
<Matters common to the first to eighth embodiments>
The covers 20A to 20G can also be applied to a vehicle 10 in which each near-infrared sensor 11 is attached to a position different from the front part of the vehicle, for example, the rear part. Examples of the target mounting location include a rear bumper. When each near-infrared sensor 11 transmits the near-infrared IR1 toward the rear of the vehicle 10, the covers 20A to 20G approach the front in the transmission direction, that is, the rear of the vehicle 10 with respect to each near-infrared sensor 11. Placed in place.

A hard coat layer having a hardness higher than that of the member may be laminated on the surface of the member constituting the outermost surface of each cover 20A to 20G. The hard coat layer is formed by applying a known surface treatment agent for resin to the surface of the member. Examples of the surface treatment agent include organic hard coat agents such as acrylate-based, oxetane-based, and silicone-based agents, inorganic hard coat agents, and organic-inorganic hybrid hard coat agents.

By doing so, it is possible to prevent the surfaces of the covers 20A to 20G from being scratched. In addition, it is possible to prevent the covers 20A to 20G from being altered or deteriorated due to sunlight, wind and rain, temperature changes, and the like.

The technical ideas that can be grasped from each of the above embodiments are described below.
(B) The near-infrared sensor cover is a plate-shaped near-infrared sensor cover arranged in front of the near-infrared transmission direction of the near-infrared sensor transmitted from the near-infrared sensor in a vehicle, and at least a part of the cover is colored in the thickness direction. It is translucent, has a near-infrared ray transmittance of 80% or more, and has a visible light ray transmittance of 70% or less.

According to the above configuration, the cover for a near-infrared sensor, which is at least partially colored and translucent in the thickness direction and has a light transmittance of 70% or less of visible light, is a cover of near-infrared rays transmitted from the near-infrared sensor. By being located in front of the transmission direction, it exerts a function of hiding the near-infrared sensor. Therefore, when looking at the cover for the near-infrared sensor, it is difficult to see the near-infrared sensor located behind the cover. Therefore, the cover for the near-infrared sensor is not used, and the appearance can be improved as compared with the case where the near-infrared sensor is attached to the vehicle in a bare state.

When near-infrared rays are transmitted from the near-infrared sensor, the near-infrared rays pass through the near-infrared sensor cover arranged in front of the transmission direction. This near-infrared ray hits an obstacle, is reflected, passes through the cover for the near-infrared ray sensor again, and is received by the near-infrared ray sensor. Since the near-infrared sensor cover has a light transmittance of 80% or more, it does not easily interfere with the transmission of near-infrared rays. Therefore, the near-infrared sensor tends to exert a function of detecting the distance and the relative speed between the vehicle and the obstacle.

(B) In the near-infrared sensor cover, at least the main part in the thickness direction is a near-infrared sensor cover composed of a cover body, and the entire cover body is colored and translucent, and the near-infrared rays in the cover body. It is preferable that the light transmittance of the visible light is 80% or more and the light transmittance of visible light is 70% or less.

According to the above configuration, the cover main body constituting at least the main part in the thickness direction of the near-infrared sensor cover exerts a function of hiding the near-infrared sensor, making the near-infrared sensor difficult to see. Therefore, the appearance of the near-infrared sensor is better than that when it is mounted on the vehicle in a bare state.

In addition, the cover body does not easily interfere with the transmission of near-infrared rays transmitted from the near-infrared sensor and near-infrared rays reflected by hitting an obstacle. Therefore, the near-infrared sensor tends to exert a detection function.

(C) In the cover for the near-infrared sensor, the cover main body has a front surface on the side far from the near-infrared sensor and a back surface on the side close to the near-infrared sensor, and the entire cover main body is the cover. It is preferable that the thickness of the main body is formed so as to gradually change in the direction along the front surface and the back surface.

According to the above configuration, in the colored translucent cover body, the color depth differs depending on the thickness. The thick part has a darker color than the thin part. Therefore, the design of the cover body is rich in variation as compared with the case where the thickness of the cover body is uniform and the color depth is constant at any part of the cover body.

Moreover, since the thickness of the cover body gradually changes in the direction along the front surface and the back surface of the cover body, the color depth changes in a continuous gradation along the front surface and the back surface. Therefore, the change in shade becomes more natural than in the case where the shade of color changes abruptly.

(D) In the near-infrared sensor cover, the main part in the thickness direction is a near-infrared sensor cover composed of a transparent cover body, and the cover body is a surface on the side far from the near-infrared sensor. It has a back surface on the side close to the near-infrared sensor, and a colored translucent layer is laminated on at least one of the front surface and the back surface of the cover body, and the colored translucent layer is laminated on the cover body. It is preferable that the light transmittance of near-infrared rays is 80% or more and the light transmittance of visible light is 70% or less.

According to the above configuration, the transparent cover body forming the main part in the thickness direction of the near-infrared sensor cover and the colored translucent layer laminated on at least one of the front surface and the back surface hide the near-infrared sensor. It works well and makes the near-infrared sensor hard to see, so it looks good.

In addition, the cover body and the colored translucent layer are less likely to interfere with the transmission of near-infrared rays transmitted from the near-infrared sensor and near-infrared rays reflected by hitting an obstacle. Therefore, the near-infrared sensor tends to exert a function of detecting the distance and the relative speed between the vehicle and the obstacle.

(E) In the near-infrared sensor cover, the cover body has a front surface on the side far from the near-infrared sensor and a back surface on the side close to the near-infrared sensor, and the front surface is formed of a flat surface. A part of the back surface is inclined with respect to the front surface so that the distance from the front surface gradually changes in the direction along the same surface, and the first plane is opposite to the first plane with respect to the front surface. It is composed of a second plane whose distance from the surface gradually changes with respect to the direction along the surface by inclining so as to have a relationship with the first plane and the second plane. It is preferable that they intersect in a sharp state.

According to the above configuration, a part of the visible light incident on the cover body from the front surface side is reflected by hitting the back surface, and the mode of reflection is different between the first plane and the second plane. Therefore, when the cover for the near-infrared sensor is viewed, the appearance differs between the first plane and the second plane, and the design of the cover body is rich in variation.

In particular, the point where the first plane and the second plane intersect in a sharp state looks like a line. Therefore, by devising the position, extending direction, length, etc. of this portion, it is possible to make the design of the cover for the near-infrared sensor rich in variation.

10 ... Vehicle, 11 ... Near infrared sensor, 20A, 20B, 20C, 20D, 20E, 20F, 20G ... Near infrared sensor cover 21,24,28 ... Cover body, 22, 25, 29 ... Surface, 23, 26 , 30 ... back surface, 27 ... colored translucent layer, 31 ... first plane, 32 ... second plane, IR1, IR1A, IR1B, IR2 ... near infrared rays, T ... thickness.

Claims (3)

A plate-shaped cover for a near-infrared sensor that is placed in front of the near-infrared ray transmitted from the near-infrared sensor in a vehicle.
The main part in the thickness direction is composed of a cover body formed of a material-coated resin material.
The cover body has a front surface on the side far from the near infrared sensor and a back surface on the side close to the near infrared sensor.
It has a tubular wall portion that surrounds the near-infrared sensor from the top, bottom, left, and right, and a flange wall portion formed around the end portion of the tubular wall portion that is closer to the cover body, and houses the near-infrared sensor. The storage case is attached with the flange wall portion close to the back surface of the cover body.
A front Kiura surface side of the cover body, the tubular wall portion and the antireflection layer on the inner wall surface of the flange wall of the housing case is stacked,
The thickness of the reflection suppression layer is set so that the near infrared rays reflected by the inner wall surface of the storage case and the near infrared rays reflected by the reflection suppression layer are in opposite phases to each other.
The light transmittance of near-infrared rays having a wavelength of 0.83 μm to 3 μm is 80% or more, and the light transmittance of visible light having a wavelength of 0.36 μm to 0.83 μm in the cover body in which the reflection suppression layer is laminated. Cover for near-infrared sensor with 70% or less. The cover for a near-infrared sensor according to claim 1 , wherein the entire cover body is formed in a shape in which the thickness of the cover body gradually changes in the direction along the front surface and the back surface. The surface is composed of flat surfaces.
A part of the back surface is inclined with respect to the front surface so that the distance from the front surface gradually changes in the direction along the same surface, and the first plane is opposite to the first plane with respect to the front surface. It is composed of a second plane whose distance from the surface gradually changes with respect to the direction along the same surface by inclining so as to have a relationship of.
The cover for a near infrared sensor according to claim 1 or 2 , wherein the first plane and the second plane intersect in a sharp state.

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