Onboard sensor cover
An onboard sensor cover includes a cover body that includes front and rear bases and a decorative layer. The front base is made of a transparent plastic material that permits passage of an infrared ray and a millimeter wave and includes a rear surface in the transmission directions of the infrared ray and the millimeter wave that is configured by a first uneven surface. The rear base is made of a plastic material that permits passage of the infrared ray and the millimeter wave and includes a front surface in the transmission directions that is configured by a second uneven surface. The decorative layer is made of a material that reflects visible light and permits passage of the infrared ray and the millimeter wave and is in contact with the first and second uneven surfaces. The front and rear bases are made of the same type of plastic material.
1. An onboard sensor cover applied to a vehicle, the vehicle including, as an onboard sensor that detects a surrounding situation, an infrared sensor that transmits an infrared ray toward an outside of the vehicle and receives the infrared ray that has struck and has been reflected by an object outside the vehicle and a millimeter wave radar device that transmits a millimeter wave toward the outside of the vehicle and receives the millimeter wave that has struck and has been reflected by the object outside the vehicle, wherein
the onboard sensor cover comprises a cover body configured to be arranged in front of the infrared sensor in a transmission direction of the infrared ray and in front of the millimeter wave radar device in a transmission direction of the millimeter wave,
the cover body includes
a front base made of a transparent plastic material that permits passage of the infrared ray and the millimeter wave, the front base including a rear surface in the transmission directions of the infrared ray and the millimeter wave, the rear surface being configured by a first uneven surface,
a rear base made of a plastic material that permits passage of the infrared ray and the millimeter wave and arranged on a rear side of the front base in the transmission directions, the rear base including a front surface in the transmission directions, the front surface being configured by a second uneven surface that corresponds to the first uneven surface of the front base, and
a decorative layer made of a material that reflects visible light and permits passage of the infrared ray and the millimeter wave, the decorative layer being in contact with the first uneven surface of the front base and the second uneven surface of the rear base between the front base and the rear base, and
the front base and the rear base are made of the same type of plastic material.
2. The onboard sensor cover according to claim 1 , wherein the decorative layer includes at least one of a cold mirror layer or an infrared ray passage ink layer.
3. The onboard sensor cover according to claim 1 , wherein when a thickness of the cover body is set as T, a wavelength of the millimeter wave is set as λe, an average value of a relative permittivity of the front base and the rear base is set as εp, and an integer is set as n, the thickness T is set to a value that satisfies an equation,
T ={(λ e/ 2)/√(ε p )} n.
4. An onboard sensor cover applied to a vehicle, the vehicle including, as an onboard sensor that detects a surrounding situation, an infrared sensor that transmits an infrared ray toward an outside of the vehicle and receives the infrared ray that has struck and has been reflected by an object outside the vehicle and a millimeter wave radar device that transmits a millimeter wave toward the outside of the vehicle and receives the millimeter wave that has struck and has been reflected by the object outside the vehicle, wherein
the onboard sensor cover comprises a cover body configured to be arranged in front of the infrared sensor in a transmission direction of the infrared ray and in front of the millimeter wave radar device in a transmission direction of the millimeter wave,
the cover body includes
a front base made of a transparent plastic material that permits passage of the infrared ray and the millimeter wave, the front base including a rear surface in the transmission directions of the infrared ray and the millimeter wave, the rear surface being configured by a first uneven surface,
a rear base made of a plastic material that permits passage of the infrared ray and the millimeter wave and arranged on a rear side of the front base in the transmission directions, the rear base including a front surface in the transmission directions, the front surface being configured by a second uneven surface that corresponds to the first uneven surface of the front base, and
a decorative layer made of a material that reflects visible light and permits passage of the infrared ray and the millimeter wave, the decorative layer being in contact with the first uneven surface of the front base and the second uneven surface of the rear base between the front base and the rear base, and
the front base and the rear base are made of a plastic material in which a difference in a refractive index between the front base and the rear base is less than or equal to 7%.
5. The onboard sensor cover according to claim 4 , wherein the decorative layer includes at least one of a cold mirror layer or an infrared ray passage ink layer.
6. The onboard sensor cover according to claim 4 , wherein when a thickness of the cover body is set as T, a wavelength of the millimeter wave is set as λe, an average value of a relative permittivity of the front base and the rear base is set as εp, and an integer is set as n, the thickness T is set to a value that satisfies an equation,
T ={(λ e/ 2)/√(ε p )} n.
7. An onboard sensor cover applied to a vehicle, the vehicle including, as an onboard sensor that detects a surrounding situation, an infrared sensor that transmits an infrared ray toward an outside of the vehicle and receives the infrared ray that has struck and has been reflected by an object outside the vehicle and a millimeter wave radar device that transmits a millimeter wave toward the outside of the vehicle and receives the millimeter wave that has struck and has been reflected by the object outside the vehicle, wherein
the onboard sensor cover comprises a cover body configured to be arranged in front of the infrared sensor in a transmission direction of the infrared ray and in front of the millimeter wave radar device in a transmission direction of the millimeter wave,
the cover body includes
a front base made of a transparent plastic material that permits passage of the infrared ray and the millimeter wave, the front base including a rear surface in the transmission directions of the infrared ray and the millimeter wave, the rear surface being configured by a first uneven surface,
a rear base made of a plastic material that permits passage of the infrared ray and the millimeter wave and arranged on a rear side of the front base in the transmission directions, the rear base including a front surface in the transmission directions, the front surface being configured by a second uneven surface that corresponds to the first uneven surface of the front base, and
a decorative layer made of a material that reflects visible light and permits passage of the infrared ray and the millimeter wave, the decorative layer being in contact with the first uneven surface of the front base and the second uneven surface of the rear base between the front base and the rear base, and
the front base and the rear base are each made of any one of plastic materials of polycarbonate plastic (PC), poly methyl methacrylate plastic (PMMA), and acrylonitrile-butadiene-styrene copolymer plastic (ABS).
8. The onboard sensor cover according to claim 7 , wherein the decorative layer includes at least one of a cold mirror layer or an infrared ray passage ink layer.
9. The onboard sensor cover according to claim 7 , wherein when a thickness of the cover body is set as T, a wavelength of the millimeter wave is set as λe, an average value of a relative permittivity of the front base and the rear base is set as εp, and an integer is set as n, the thickness T is set to a value that satisfies an equation,
T ={(λ e/ 2)/√(ε p )} n.