A cleaning robot has an optical measuring device for determining the type of surface to be cleaned. The optical measuring device has a light source and at least two light sensors. Light emitted by the light source hits a reflection point of the surface at an angle of incidence (), and is reflected to the first light sensor at a corresponding angle of reflection (). The light source, reflection point and first light sensor span a plane of incidence. A secondary plane that intersects the reflection point and has a second light sensor spans perpendicular to the surface, and exhibits an angle () of between 80 and 100 relative to the plane of incidence. A straight line running through the reflection point and second light sensor has an angle () relative to the surface that is essentially as large as the angle of incidence () or angle of reflection ().

An information processing apparatus generates a signal value for forming an image of an object as a recording layer on a recording medium. The apparatus inputs a characteristic of specular reflection light, a characteristic of internal diffuse reflection light, and a characteristic of surficial diffuse reflection light. Then, the apparatus derives, based on the characteristic of the internal diffuse reflection light, a first signal value for a first recording layer to be formed on the recording medium, and derives, based on the characteristic of the specular reflection light and the characteristic of the surficial diffuse reflection light, a second signal value for a second recording layer different from the first recording layer to be formed on the recording medium.

A toner detection unit is configured by an LED that irradiates light toward an intermediate transfer belt, first and second light receiving elements that respectively receive specular reflection light and diffused reflection light of light irradiated toward the intermediate transfer belt from the LED, a circuit board, and a housing. The LED and the light receiving elements are mounted in a line on the circuit board. The housing is configured to guide, to the first light receiving element, the specular reflection light from a first region within an irradiation region on which light is irradiated from the LED on the intermediate transfer belt, and to guide, to the second light receiving element, the diffused reflection light from a second region which is different from the first region within the irradiation region.

A sheet discriminator, which is incorporated in an image forming apparatus and an image forming system, includes a sheet loader on which a recording medium is loaded, an information detector including a light emitter to emit light to a surface of the recording medium loaded on the sheet loader and a light receiver to receive the light emitted by the light emitter and detecting information of the recording medium, a sheet distinguisher to distinguish a type of the recording medium based on the information detected by the information detector, and a light emission controller to control activation and stop of the light emitter and activate the light emitter before the information detector starts detection of the information of the recording medium.

A sheet discriminator, which can be included in an image forming apparatus, includes an optical information detector, a sheet distinguisher, and a sheet thickness detector. The optical information detector includes a light emitter to emit light to a recording medium and a light receiver to receive the light and detects information of the recording medium. The sheet distinguisher distinguishes a type of the recording medium based on the information detected by the optical information detector. The sheet thickness detector includes a displacement gauge to sandwich the recording medium with an opposing member disposed facing the displacement gauge and to move from an initial position thereof and a displacement detector to detect an amount of displacement of the displacement gauge. The sheet thickness detector detects a thickness of the recording medium based on detection results obtained by the displacement detector.

An illumination system for recognizing material includes a measurement stage, a light-providing part, a light-receiving part, and a processing part. The measurement stage is upwardly open and the measurement target is located on the measurement stage. The light-providing part includes a plurality of illumination sections providing incident lights to the measurement target, and provides multi-directional incident lights to the measurement target from multiple upper directions at which the measurement stage is open. The light-receiving part receives single-directional reflection lights reflected by the measurement target according to the multi-directional incident lights provided by the light-providing part. The processing part acquires a multi-directional intensity distribution of multi-directional reflection lights reflected by the measurement target according to a single-directional incident light from the single-directional reflection lights reflected by the measurement target according to the multi-directional incident lights, and determines material of the measurement target from the multi-directional intensity distribution of reflection lights. Thus, material of an object may be easily and accurately known at a low cost.

According to an embodiment, an optical inspection method includes: causing a wavelength selection portion to selectively pass light components including at least two different wavelength spectra from an object point and causing an imaging portion including at least two color channels configured to receive the light components of the wavelength spectra to capture the object point; defining the light components of the at least two different wavelength spectra as signal vectors having different directions based on light reception data in the at least two color channels for the object point; and estimating spread of a direction distribution of light at the object point based on the directions of the signal vectors.

A system includes a radiation source configured to emit a radiation beam. The system further includes a first optical sensor configured to detect a first intensity of a first portion of the radiation beam reflected from a surface of an object. The system further includes a second optical sensor configured to detect a second intensity of a second portion of the radiation beam scattered by the surface of the object. The system further includes a processing device communicatively coupled to the first optical sensor and the second optical sensor. The processing device is configured to determine at least one of a roughness or an emissivity of the surface of the object based on a comparison of the first intensity and the second intensity.

A method for extracting spectral information of a substance under test includes: identifying a pixel region A(x, y) occupied by an object under test from a hyperspectral image acquired; extracting a specular reflection region A.sub.q and a diffuse reflection region A.sub.r from the pixel region A(x, y), and calculating a representative spectrum I.sub.q(?) of the specular reflection region A.sub.q and a representative spectrum I.sub.r(?) of the diffuse reflection region A.sub.r, respectively; by comparing each element in the representative spectrum I.sub.q(?) of the specular reflection region A.sub.q with each element in the representative spectrum I.sub.r(?) of the diffuse reflection region A.sub.r, separating information of a light source from spectral information of the object to obtain a first spectral invariant C(?). This method does not require additional spectral information of the light source, which improves the analysis efficiency.

Methods for profiling a bore of an engine block are provided. Methods can comprise profiling the bore surface with a qualitative optical device (QlOD) to determine a qualitative surface characteristic map of the bore surface, wherein the QlOD comprises a light source configured to emit light toward the bore surface at an emitting angle, and a sensor array configured to sense scattered light reflected from the bore surface, and comparing the qualitative surface characteristic map to a calibration value to determine the suitability of the bore surface for thermal spray deposition. Methods can further include profiling the bore surface with a quantitative optical device (QnOD) to determine a quantitative surface characteristic, and determining a quantitative-qualitative correlation. Methods can further include profiling additional sample areas of the bore surface with the QlOD to determine a qualitative surface characteristic map of the bore surface and applying the correlation to the map.