Abstract: A water content sensor includes: a light emitter that emits detection light having a first wavelength band and reference light a second wavelength band toward a road surface; a first light receiver that converts the detection light reflected by the road surface to a first electric signal; a second light receiver that converts the reference light reflected by the road surface to a second electric signal; and a computation processor that detects the amount of water based on a signal ratio between the first electric signal and the second electric signal. The computation processor detects the amount of water based on the signal ratio obtained when the signal intensity of at least one of the first electric signal and the second electric signal is within a predetermined range defined relative to a reference value.

Abstract: A moisture amount detection device includes: a light source that projects light that flickers at a predetermined frequency toward an object; a light receiver that receives the light reflected by the object and outputs a detection signal; an amplifier that outputs an amplified signal obtained by amplifying the detection signal by a predetermined amplification factor; a lock-in amplifier that outputs an extracted signal obtained by extracting a signal of a predetermined frequency from the amplified signal; an A/D converter that performs A/D conversion on the extracted signal, and outputs a digital signal; a second low-pass filter whose passband is changeable, and that allows a signal of a frequency in the passband in the digital signal to pass therethrough; and a controller that performs first control to change the passband according to a signal intensity indicated by the digital signal.

Abstract: A water content sensor includes: a light emitter that emits detection light having a first wavelength band and reference light a second wavelength band toward a road surface; a first light receiver that converts the detection light reflected by the road surface to a first electric signal; a second light receiver that converts the reference light reflected by the road surface to a second electric signal; and a computation processor that detects the amount of water based on a signal ratio between the first electric signal and the second electric signal. The computation processor detects the amount of water based on the signal ratio obtained when the signal intensity of at least one of the first electric signal and the second electric signal is within a predetermined range defined relative to a reference value.

Abstract: A moisture amount detection device includes: a light source that projects light that flickers at a predetermined frequency toward an object; a light receiver that receives the light reflected by the object and outputs a detection signal; an amplifier that outputs an amplified signal obtained by amplifying the detection signal by a predetermined amplification factor; a lock-in amplifier that outputs an extracted signal obtained by extracting a signal of a predetermined frequency from the amplified signal; an A/D converter that performs A/D conversion on the extracted signal, and outputs a digital signal; a second low-pass filter whose passband is changeable, and that allows a signal of a frequency in the passband in the digital signal to pass therethrough; and a controller that performs first control to change the passband according to a signal intensity indicated by the digital signal.

Abstract: A luminaire includes an excitation light source which emits excitation light. A first fluorescent plate includes a first principle surface disposed across the optical axis of the excitation light. A first phosphor layer is arranged discretely along the first principle surface. A second fluorescent plate is arranged at the downstream side of the excitation light with respect to the first fluorescent plate. The second fluorescent plate includes a second principle surface disposed across the optical axis. A second phosphor layer is arranged discretely along the second principle surface. The second phosphor layer has a wavelength conversion characteristic different from a wavelength conversion characteristic of the first phosphor layer. A support supports the first fluorescent plate and the second fluorescent plate such that at least one of relative positions and rotations of the first fluorescent plate and the second fluorescent plate are adjustable.

Abstract: A separator includes a rotor, a plurality of flow channels each of which has an inlet and an outlet for gas and are in a vicinity of a rotation axis of the rotor, an air current producer configured to cause gas to flow through the plurality of flow channels, a driving device configured to rotate the rotor to rotate the plurality of flow channels around the rotation axis, and a discharger for allowing discharge of solid materials suspended in airstream produced in each of the plurality of flow channels, in a direction away from the rotation axis.

Abstract: A particle sensor is provided. The particle sensor includes a light projector that projects light to a detection area. A light receiver receives scattered light. The scattered light is light from the light projector that has been scattered by particles in the detection area. A first reflector reflects the scattered light to the light receiver. A light attenuator attenuates stray light that exits the first reflector. The first reflector includes a first aperture that introduces the light from the light projector into an interior of the first reflector and a second aperture that exits the stray light from the first reflector. The light attenuator includes a third aperture through which the stray light that exits the first reflector passes. An aperture area of the third aperture is smaller than an aperture area of the second aperture.

Abstract: A particle sensor is provided. The particle sensor includes a light projector that projects light to a detection area. A light receiver receives scattered light. The scattered light is light from the light projector that has been scattered by particles in the detection area. A first support supports the light receiver. A second support supports the light projector and has a linear expansion coefficient different from a linear expansion coefficient of the first support. The first support includes a first placement region in which the light receiver is disposed and a second placement region in which the second support is disposed. The first placement region and the second placement region are located at different distances from at least one of an optical axis of the light projector and an optical axis of the light receiver.

Abstract: A separator includes a rotor, a plurality of flow channels each of which has an inlet and an outlet for gas and are in a vicinity of a rotation axis of the rotor, an air current producer configured to cause gas to flow through the plurality of flow channels, a driving device configured to rotate the rotor to rotate the plurality of flow channels around the rotation axis, and a discharger for allowing discharge of solid materials suspended in airstream produced in each of the plurality of flow channels, in a direction away from the rotation axis.

Abstract: A particle sensor includes: a detecting area into which a gas including particles is introduced; a light-projecting element; a light-receiving element which receives scattered light of the light reflected by the particles in the gas in the detecting area; a heater which heats the gas; a reflector which directs the scattered light to the light-receiving element, wherein the reflector includes: a first ellipsoidal portion having an inner surface shape that defines a portion of a surface of revolution of a spheroid; and a first spherical portion having an inner surface shape that defines a portion of a spherical surface of a sphere, wherein the first ellipsoidal portion has one focus of the spheroid located in the detecting area and the other focus of the spheroid located at or proximate to the light-receiving element, and the first spherical portion has a center of the sphere located in the detecting area.

Abstract: A luminaire includes an excitation light source which emits excitation light. A first fluorescent plate includes a first principle surface disposed across the optical axis of the excitation light. A first phosphor layer is arranged discretely along the first principle surface. A second fluorescent plate is arranged at the downstream side of the excitation light with respect to the first fluorescent plate. The second fluorescent plate includes a second principle surface disposed across the optical axis. A second phosphor layer is arranged discretely along the second principle surface. The second phosphor layer has a wavelength conversion characteristic different from a wavelength conversion characteristic of the first phosphor layer. A support supports the first fluorescent plate and the second fluorescent plate such that at least one of relative positions and rotations of the first fluorescent plate and the second fluorescent plate are adjustable.

Abstract: A particle sensor is provided. The particle sensor includes a light projector that projects light to a detection area. A light receiver receives scattered light. The scattered light is light from the light projector that has been scattered by particles in the detection area. A first support supports the light receiver. A second support supports the light projector and has a linear expansion coefficient different from a linear expansion coefficient of the first support. The first support includes a first placement region in which the light receiver is disposed and a second placement region in which the second support is disposed. The first placement region and the second placement region are located at different distances from at least one of an optical axis of the light projector and an optical axis of the light receiver.

Abstract: A particle sensor is provided. The particle sensor includes a light projector that projects light to a detection area. A light receiver receives scattered light. The scattered light is light from the light projector that has been scattered by particles in the detection area. A first reflector reflects the scattered light to the light receiver. A light attenuator attenuates stray light that exits the first reflector. The first reflector includes a first aperture that introduces the light from the light projector into an interior of the first reflector and a second aperture that exits the stray light from the first reflector. The light attenuator includes a third aperture through which the stray light that exits the first reflector passes. An aperture area of the third aperture is smaller than an aperture area of the second aperture.

Abstract: A particle sensor includes: a detecting area into which a gas including particles is introduced; a light-projecting element; a light-receiving element which receives scattered light of the light reflected by the particles in the gas in the detecting area; a heater which heats the gas; a reflector which directs the scattered light to the light-receiving element, wherein the reflector includes: a first ellipsoidal portion having an inner surface shape that defines a portion of a surface of revolution of a spheroid; and a first spherical portion having an inner surface shape that defines a portion of a spherical surface of a sphere, wherein the first ellipsoidal portion has one focus of the spheroid located in the detecting area and the other focus of the spheroid located at or proximate to the light-receiving element, and the first spherical portion has a center of the sphere located in the detecting area.

Abstract: Infrared radiation device and production method, capable of preventing electrode degradation by heat are provided. Infrared radiation device includes substrate, insulation layer, heat generating layer, electrode, foundation portion and electric conductor. Substrate has cavity exposing part of back surface of insulation layer. Foundation portion exists on inside and outside of vertical projection area (projection direction of which is along thickness direction of insulation layer) of opening edge, on surface of substrate, of cavity. Electric conductor is provided on surface of foundation portion. End of heat generating layer is provided as cover covering electric conductor. Electrode is in contact with surface of covering outside vertical projection area. Conductor has higher melting point than that of electrode and smaller electrical resistance than those of portion and layer.

Abstract: An infrared radiation element includes: a first insulating layer having heat insulating properties and electrically insulating properties; a heating element layer provided on the first insulating layer and configured to radiate infrared radiation when energized; and a second insulating layer provided on an opposite side of the heating element layer from the first insulating layer and having heat insulating properties and electrically insulating properties. The second insulating layer transmits the infrared radiation radiated from the heating element layer. The heating element layer has such a sheet resistance that impedance of the heating element layer matches impedance of space which is in contact with the second insulating layer.

Abstract: An infrared radiation element includes: a first insulating layer having heat insulating properties and electrically insulating properties; a heating element layer provided on the first insulating layer and configured to radiate infrared radiation when energized; and a second insulating layer provided on an opposite side of the heating element layer from the first insulating layer and having heat insulating properties and electrically insulating properties. The second insulating layer transmits the infrared radiation radiated from the heating element layer. The heating element layer has such a sheet resistance that impedance of the heating element layer matches impedance of space which is in contact with the second insulating layer.