A medium identification device identifies a type of a recording medium used for image formation. The medium identification device includes: a two-dimensional image sensor that captures an image of the recording medium; and an identifying unit that obtains a glossiness evaluation value indicating glossiness of the recording medium, a surface roughness evaluation value indicating surface roughness of the recording medium, and a coloring evaluation value indicating coloring of the recording medium, using image data of a specular reflection region reflecting specular reflection light from the recording medium and image data of a diffused reflection region reflecting diffused reflection light from the recording medium, the regions being in the image of the recording medium, and identifies the type of the recording medium by combining determination using the glossiness evaluation value, determination using the surface roughness evaluation value, and determination using the coloring evaluation value.

A human body detection sensor includes: a detection decision unit that decides whether a state is a detection state or a non-detection state of a detection target; a specular reflection decision unit that decides whether or not reflected light that is incident onto a line sensor is specularly-reflected light; and a continuation decision unit that decides whether or not a state in which the detection target exists is ongoing, wherein, when specularly-reflected light is detected while a determination is made indicating the detection state, the detection decision unit keeps the result of a determination indicating the detection state without change if the result of the decision by the continuation decision unit indicates that the state is ongoing and changes the determination to a determination indicating the non-detection state if the result of the decision shows any other states.

A specular variable angle absolute reflectometer includes a light source and a mirror system in a light path of the light source. The mirror system is configured to reflect a light beam from the light source towards a sample that is optically reflective. The device also includes an elliptical roof mirror disposed in the light path after the sample having an ellipsoidal reflector surface configured to reflect the light beam back towards the sample. The device also includes a mechanism connected to the elliptical roof mirror. The mechanism is configured to rotate the elliptical roof mirror about an axis of the sample. The device also includes a detector in the light path after the elliptical roof mirror such that the detector receives light that has been reflected from the elliptical roof mirror, thence back to the sample, thence back to the mirror system, and thence to the detector.

A specular variable angle absolute reflectometer includes a light source and a mirror system in a light path of the light source. The mirror system is configured to reflect a light beam from the light source towards a sample that is optically reflective. The device also includes an elliptical roof mirror disposed in the light path after the sample having an ellipsoidal reflector surface configured to reflect the light beam back towards the sample. The device also includes a mechanism connected to the elliptical roof mirror. The mechanism is configured to rotate the elliptical roof mirror about an axis of the sample. The device also includes a detector in the light path after the elliptical roof mirror such that the detector receives light that has been reflected from the elliptical roof mirror, thence back to the sample, thence back to the mirror system, and thence to the detector.

A surface characteristics evaluation method for evaluating a surface characteristic of a painted surface including a glittering material, including: a multi-angle condition image acquisition step S101 for acquiring a multi-angle condition image including multi-angle conditions in a continuous manner by performing an image-capturing process to capture how a reflection condition of the painted surface changes when rotating an illumination device 2 emitting light onto the painted surface, the image-capturing process being performed by the line scan camera 4 while a sample P having the painted surface is moved in a certain direction; an in-plane chromaticity distribution acquisition step S102 for acquiring an in-plane chromaticity distribution of the painted surface from the multi-angle condition image acquired; and a surface characteristics evaluation step S107 for calculating particle characteristics S as surface characteristics evaluation values of the multi-angle conditions, on the basis of the in-plane chromaticity distribution acquired.

A system for inspecting a coating on a substrate, the system including a platform that receives a sample including the substrate having the coating, and a light source that directs a plurality of electromagnetic pulses towards a scanning location on the coating, wherein the light source is oriented to direct the plurality of electromagnetic pulses at an oblique angle relative to a surface of the coating. A light detector receives electromagnetic pulses reflected from the sample, wherein a first portion of each electromagnetic pulse is reflected from the surface of the coating, and a second portion of each electromagnetic pulse is reflected from a surface of the substrate. An actuator is coupled to the platform and/or the light source, wherein the actuator moves the platform and the light source relative to each other such that the plurality of electromagnetic pulses are directable towards the scanning location from different rotational positions.

A system for inspecting a coating on a substrate, the system including a platform that receives a sample including the substrate having the coating, and a light source that directs a plurality of electromagnetic pulses towards a scanning location on the coating, wherein the light source is oriented to direct the plurality of electromagnetic pulses at an oblique angle relative to a surface of the coating. A light detector receives electromagnetic pulses reflected from the sample, wherein a first portion of each electromagnetic pulse is reflected from the surface of the coating, and a second portion of each electromagnetic pulse is reflected from a surface of the substrate. An actuator is coupled to the platform and/or the light source, wherein the actuator moves the platform and the light source relative to each other such that the plurality of electromagnetic pulses are directable towards the scanning location from different rotational positions.

A measuring apparatus that measures an optical characteristic of a surface in accordance with a standard selected from a plurality of standards is provided. The apparatus includes an illumination device configured to illuminate the surface with light from a light source, an imaging device configured to image the light source with reflected light from the surface illuminated by the illumination device, and a processor configured to process image data having number of pixels obtained by reducing number of pixels of the imaging device by a reduction rate to obtain the optical characteristic of the surface. The processor is configured to determine the reduction rate based on the selected standard.

A specular variable angle absolute reflectometer. The device includes a light source and a mirror system in a light path of the light source. The mirror system is configured to reflect a light beam from the light source towards a sample that is optically reflective. The device also includes a roof mirror disposed in the light path after the sample. The roof mirror is configured to reflect the light beam back towards the sample. The device also includes a mechanism connected to the roof mirror. The mechanism is configured to rotate the roof mirror about an axis of the sample. The device also includes a detector in the light path after the roof mirror such that the detector receives light that has been reflected from the roof mirror, thence back to the sample, thence back to the mirror system, and thence to the detector.

A retroreflective optical system for creating a passive optical tag in an absence of electrical power, involving: a retroreflector having a surface and a retroreflective element disposed in relation to the surface, the retroreflective element configured to: passively impart a unique signature in relation to incoming light by using at least one of spectral filtration and color filtration, whereby a plasmonic response is effectible; and reflect outgoing light having the unique signature; and an optical device having an input aperture, the optical device disposed at a distance from the retroreflector and configured to transmit the incoming light and the outgoing light.