Abstract: An alumina powder containing alumina particles, wherein among the alumina particles, an average sphericity of an alumina particle having a projected area equivalent circle diameter of 50 nm or more as determined by microscopy is 0.80 or more, a content ratio of an alumina particle having a particle diameter of 75 ?m or more is 0.05% by mass or less, an average particle diameter of the alumina powder is 0.2 ?m or more and 15 ?m or less, the average particle diameter is a particle diameter measured using a laser light diffraction scattering particle size distribution analyzer, and an amount of water included in the alumina powder measured by a specific measurement method is 30 ppm or more and 500 ppm or less.

Abstract: An image processing apparatus includes a light source configured to emit light onto a glass; an image-capturing unit configured to capture light from an image-capturing region including reflection light of the emitted light from the glass; an object detection filter used to detect an object attached to the glass, light from a portion of the image-capturing region entering the object detection filter; an exposure control unit configured to determine a first exposure amount used in image capturing for a first region where the object detection filter does not exist and a second exposure amount used in image capturing for a second region where the object detection filter exists; and an image analysis unit configured to analyze a captured image obtained by the image-capturing unit. The image-capturing unit switches an exposure amount used in an image-capturing process for the image-capturing region between the first exposure amount and the second exposure amount.

Abstract: An attached matter detector includes a light source configured to irradiate light toward a plate-like transparent member from one surface thereof, an imaging device configured to image reflection light by attached matter on a surface of the plate-like transparent member, a memory configured to previously store flare information obtained by the image device by turning on the light source in a state without having disturbance light and the attached matter on the surface of the plate-like transparent member, and a difference information-obtaining device configured to obtain difference information between a light-up image as an image obtained by the imaging device with the turned-on light source and a light-out image as an image obtained by the imaging device with the turned-off light source, wherein the attached matter on the surface of the plate-like transparent member is detected based on the difference information and the flare information stored in the memory.

Abstract: An imaging device includes an optical filter. The optical filter has a configuration in which a polarization filter layer and a spectral filter layer are laminated in light transmission direction. Of the polarization filter layer and the spectral filter layer, the layer on the lower side in lamination direction has an uneven top face in the lamination direction. The optical filter is formed by filling the uneven top face with a predetermined filling material so as to even out the top face and then forming other layer.

Abstract: An object identifying apparatus is disclosed, including: an imaging part, and an object identification processing part. The imaging part receives two polarized lights having a different polarization direction included in light reflected from the object existing in the image pickup area and captures two polarization images. The object identification processing part conducts an identification process for identifying the object existing at a place corresponding to each of multiple process areas in the image pickup area by using the two polarization images captured by the imaging part.

Abstract: An attached matter detector includes a light source; an imager receiving transmitted light from a predetermined imaging region on a light-receiving region for an imaging region and imaging an image of the imaging region, and receiving reflected light on a light-receiving region for attached matter detection when light from the light source is reflected by attached matter and imaging an image of the attached matter; a parameter calculator of an image for an attached matter image region calculating a parameter of an image for an attached matter image region as information of an image region of the attached matter; a parameter calculator of an image for an imaging region calculating a parameter of an image for an imaging region as information of the imaging region; and an output device of an attached matter state signal outputting a signal showing a state of the attached matter based on the calculated parameters.

Abstract: A substance detection apparatus and method including a light source to emit light to a planar transparent member having a proximal first face and a distal second face opposite the first face, the light from the light source first striking the first face of the planar transparent member. The substance detection apparatus and method including an image capture lens, a polarization filter, an image sensor, and a substance detection processor. The light emitted from the light source is reflected at the substance present on the second face of the planar transparent member, and the image sensor receives light reflected from the substance, via the image capture lens and the polarization filter, to capture an image of the substance present on the second face of the planar transparent member.

Abstract: A disclosed transparent body detection system includes an image acquisition unit acquiring a vertical polarization image and a horizontal polarization image by acquiring an image of a first region, the image including a transparent body having characteristics in which a polarization direction of transmission light changes; a placing table on which the transparent body is to be placed; a polarization filter disposed opposite to the image acquisition unit across the placing table and at a position including a second region, an image of the second region including at least the transparent body in the first region and being acquired; and an image processing apparatus detecting the transparent body based on distribution of vertical/lateral polarization degree of a vertical/lateral polarization degree image based on the vertical polarization image and the horizontal polarization image.

Abstract: An image pickup lens has a focal length far from a position of a transparent member. An image pickup device is put on the side of the transparent member the same as that of a light source and takes reflected light including regular reflection from an interface between an adhered object on the other surface of the transparent member and air. Assuming an incident angle of the emitted light on the transparent member when the light reflected in regular reflection by the other surface of the transparent member is incident on the image pickup lens being ?s, an incident angle of a typical light beam of the emitted light falls within ?s?30 deg through ?s and an incident angle of a main element of the emitted light is less than ?s.

Abstract: An imaging unit includes a light source placed on one surface of a light transmissive plate-like element to project a light to the one surface of the plate-like element, an imaging element to capture an image of an attached matter on the other surface of the plate-like element illuminated with the light from the light source, and an optical element having an incidence surface on which the light is incident from the light source, a reflective surface by which the light incident from the incidence surface is reflected, a transmissive surface contacting the one surface of the plate-like element, through which the light reflected by the reflective surface transmits, and an exit surface from which the light transmitting through the transmissive surface and reflected by the other surface of the plate-like element is emitted towards the imaging element.

Abstract: An object identification device includes an image capturing device to capture images polarized in different directions. A noise removal unit removes noise in the polarized images using a noise removing parameter. An index value computing unit computes an object identification index value for identification-processing areas in the polarized images using data of noise-removed polarized images. An object identification processing unit conducts object identification by determining identification processing areas corresponding to an identification target object based on the object identification index value. An environment information obtaining unit obtains environment information. An environmental condition determination unit determines an environmental condition based on the environment information. A parameter storage unit stores noise removing parameters prepared for mutually exclusive environmental conditions.

Abstract: An imaging unit includes a light source, an imaging element to receive a light having entered an outer surface of the transparent plate-like member from a predetermined imaging area and transmitted through the transparent plate-like member and a light from the light source reflected by an attached matter on the outer surface, to capture an image of the predetermined imaging area and that of the attached matter, a mirror module fixed on the internal surface of the transparent plate-like member to fixedly support a reflective mirror to reflect the light from the light source, an imaging module to fixedly support the light source and the imaging element, fixed relative to the internal surface of the transparent plate-like member so that the imaging element captures an image in a certain direction, and a positioning mechanism to determine relative positions of the mirror module and the imaging module.

Abstract: A foreign substance detection system includes an optical device having an input surface through which is part of light emitted from a light source enters the optical device and a transparent face, provided in close contact with an inner surface of a glass, to transmit a light reflected from an area where a substance is not present on an outer surface of the glass toward a first light-receiving member; a light-guiding member to guide another part of the light that does not pass through the input surface, the guided light being to be reflected from an area where a substance is present on an inner surface of the glass toward a second light-receiving member; and an foreign substance detection processor to detect an outer substance based on the first light-receiving member and detect the inner substance based on the second light-receiving member.

Abstract: A vehicle detection device having an imaging device to capture two respective polarized images from two polarized light beams having different polarization directions contained in light received from an imaging area including a road surface on which one's own vehicle is traveling and a vehicle traveling on the road surface and a polarization difference calculation device to calculate a polarization difference indicating the ratio of a luminance difference between the two respective polarized images to the luminance total thereof for respective identification processing areas formed by dividing the two respective polarized images taken by the imaging device, and a vehicle area detection device to conduct a vehicle area detection process of detecting a vehicle area displaying the vehicle in the imaging area based on the polarization difference of the respective identification processing areas calculated by the polarization difference calculation device.

Abstract: An image processing apparatus includes a light source configured to emit light onto a glass; an image-capturing unit configured to capture light from an image-capturing region including reflection light of the emitted light from the glass; an object detection filter used to detect an object attached to the glass, light from a portion of the image-capturing region entering the object detection filter; an exposure control unit configured to determine a first exposure amount used in image capturing for a first region where the object detection filter does not exist and a second exposure amount used in image capturing for a second region where the object detection filter exists; and an image analysis unit configured to analyze a captured image obtained by the image-capturing unit. The image-capturing unit switches an exposure amount used in an image-capturing process for the image-capturing region between the first exposure amount and the second exposure amount.

Abstract: An image pickup lens has a focal length far from a position of a transparent member. An image pickup device is put on the side of the transparent member the same as that of a light source and takes reflected light including regular reflection from an interface between an adhered object on the other surface of the transparent member and air. Assuming an incident angle of the emitted light on the transparent member when the light reflected in regular reflection by the other surface of the transparent member is incident on the image pickup lens being ?s, an incident angle of a typical light beam of the emitted light falls within ?s?30 deg through ?s and an incident angle of a main element of the emitted light is less than ?s.

Abstract: An imaging element includes a light receiving surface having pixels, and a low-pass filter device configured to focus predetermined light on a predetermined pixel of the pixels of the light-receiving surface.

Abstract: An attached matter detector includes a light source configured to irradiate light toward a plate-like transparent member from one surface thereof, an imaging device configured to image reflection light by attached matter on a surface of the plate-like transparent member, a memory configured to previously store flare information obtained by the image device by turning on the light source in a state without having disturbance light and the attached matter on the surface of the plate-like transparent member, and a difference information-obtaining device configured to obtain difference information between a light-up image as an image obtained by the imaging device with the turned-on light source and a light-out image as an image obtained by the imaging device with the turned-off light source, wherein the attached matter on the surface of the plate-like transparent member is detected based on the difference information and the flare information stored in the memory.

Abstract: An object identification device identifying an image region of an identification target includes an imaging unit receiving two polarization lights and imaging respective polarization images, a brightness calculation unit dividing the two polarization images into processing regions and calculating a brightness sum value between the two polarizations images for each processing region, a differential polarization degree calculation unit calculating a differential polarization degree for each processing region, a selecting condition determination unit determining whether the differential polarization degree satisfies a predetermined selecting condition, and an object identification processing unit specifying the processing region based on the differential polarization degree or the brightness sum value depending on whether the predetermined selecting condition is satisfied and identifying plural processing regions that are specified as the processing regions as the image region of the identification target.

Abstract: An optical element transmits incident light having a particular polarization direction mainly by 0-order transmission and diffracts incident light having a perpendicular polarization direction. The optical element includes a periodic structure having a period equal to or greater than the wavelength of the incident light. The periodic structure includes first and second subwavelength concave-convex structures formed perpendicularly adjacent to each other in each period of the periodic structure. The first and the second subwavelength concave-convex structures have a period less than the wavelength of the incident light. A filling factor and a groove depth of the first and the second subwavelength concave-convex structures are determined such that they have the same effective refraction index with respect to the incident light having the particular polarization direction and a phase difference ? with respect to the incident light having the particular polarization direction.