An illumination unit comprising a first electromagnetic wave source including circuitry for outputting a first electromagnetic wave in a first direction to illuminate a first region of a sample; a second electromagnetic wave source including circuitry for outputting a second electromagnetic wave in a second direction substantially opposite to the first direction; and a reflector configured to reflect the second electromagnetic wave substantially in the first direction to illuminate a second region of the sample.

A measuring apparatus includes an illuminator including a light source to emit light onto an object being conveyed in a conveyance direction; a first diffuser plate; a second diffuser plate between the first diffuser plate and the object; a light shield portion between the second diffuser plate and the object; and a light receiver to receive light specularly reflected from the object illuminated by the illuminator. The light shield portion has an opening that includes an optical axis of light emitted from the light source and reaching the second diffuser plate.

A measuring apparatus includes an illuminator and a light receiver. The illuminator includes a light source to emit a light beam to an object conveyed in a conveyance direction; and a diffuser plate to diffuse the light beam emitted from the light source to illuminate a surface of the object with a diffused light beam. The light receiver receives reflection light specularly reflected from the surface of the object illuminated by the illuminator. A conditional expression below is satisfied:

L1>L2 where L1 denotes a distance between the light source and the diffuser plate, and L2 denotes a distance between the diffuser plate and the surface of the object.

A measurement apparatus for measuring a measurement target object conveyed in a conveying direction, the measurement apparatus including an illuminating unit configured to illuminate the measurement target object; and a light receiving unit configured to receive specular reflection light from the measurement target object illuminated by the illuminating unit. The illuminating unit includes a light source and a first diffusion plate, the light source including a plurality of point light sources, a plurality of the light sources are arranged in a predetermined arrangement direction, the plurality of point light sources are arranged in an orthogonal direction that is orthogonal to the predetermined arrangement direction, and when a diffusion angle relative to the predetermined arrangement direction of the first diffusion plate is given as Ax and a diffusion angle relative to the orthogonal direction is given as Ay, a relationship of Ax<Ay is satisfied.

Illumination systems and methods of designing and construction of the same are disclosed. The resulting illumination systems comprising both Front and Back light modules, provides selectable and programmable illumination according to the requirements of the invention for optimal performance of enhancing defects on a multidimensional object. The light guides are suitably aligned to the Backlight module and mechanically integrated with spring loaded mechanisms to enable them to move freely and subsequently re-postion them to a reference home position as determined at the time of setup of the illumination assembly. The Front light module is utilised to highlight surface defects and mechanically integrated to the illumination system. The illumination modules, may include multiple discrete light emitting components of different spatial intensity distribution and color spectrum mounted in specific layout such that the application oriented combined illuminating effect is created.

A method for monitoring the compliance of a container having a substantially cylindrical shape includes: rotating the container about its longitudinal axis; illuminating the rotating container with a first light source having a first wavelength, thereby generating a first image representative of any incohesive particles that may be present on an inner and/or outer surface of the container; illuminating the rotating container with a second light source having a second wavelength, thereby generating a second image representative of any defects on the surface of the container; acquiring the first image by means of a first acquisition device; acquiring the second image by means of a second acquisition device; comparing the first image and the second image with reference parameters, and notifying any defects of the container as a function of the comparison; wherein the first light source has a different wavelength than the second light source.

A device for detecting foreign substances comprising: a lighting unit for irradiating light toward an object that is brighter in one direction than other directions or uniformly irradiating light toward the object; a photographing unit spaced from the lighting unit and capable of photographing the object; a controller capable of: allowing the photographing unit to the photograph the object each time the lighting unit irradiates light toward the object that is brighter in one direction than other directions, and controlling the lighting unit and the photographing unit to allow the photographing unit to photograph the object if the lighting unit uniformly irradiates light toward the object; and a processor capable of synthesizing images photographed by the photographing unit and determining whether the object has foreign substances from the synthesized image.

The invention relates to a luminaire element (10, 11) for an inspection tunnel (100), in particular for checking shiny surfaces, in particular painted surfaces, comprising at least two, preferably strip-like, arrangements (12) of light sources (13) in a luminaire housing (14) having at least two edge regions (15) lying opposite one another along a longitudinal extension (L) of the luminaire housing (14), wherein the strip-like arrangements (12) of the light sources (13) are formed along the longitudinal extension (L) at the edge regions (16), wherein a light exit surface (20) of the luminaire housing (14) has a higher radiation intensity along the edge regions (16) than in a central region (30). The invention further relates to a luminaire strip (50) having an arrangement of luminaire elements (10, 11) of this kind and to an inspection tunnel having an arrangement of a plurality of luminaire strips (50).

A plurality of surface images are picked up while changing a relative posture of a surface of an object to be inspected with respect to an image pickup part configured to pick up an image of the surface of the object to be inspected under a state in which the surface of the object to be inspected is irradiated with light, and a defect and luminance unevenness of the surface of the object to be inspected are discriminated from each other based on a change in the plurality of surface images.

Systems and methods for capturing images of pearls and determining characteristic grades of the pearls are provided. A top digital camera can capture a first digital image of the pearl. A stage can support the pearl and can move in any of an X/Y/Z direction. A concave diffuser can direct diffused light on one side of the pearl, and a side LED arrangement can illuminate the concave diffuser, the stage, and a second side of the pearl. A side digital camera can capture a second digital image of the pearl. A computer can obtain the digital images of the pearl and perform analysis to determine one or more characteristic grades for the pearl.