The methods herein utilize polarized light for detecting through holes in substrates. A light source directs light through a first polarization filter having a first polarization axis, wherein polarized light travels from the first polarization filter and toward a substrate. The orientation of the polarized light is changed while traveling through substrate material, and is scattered. However, polarized light traveling through a hole in the substrate remains unscattered. A second polarization filter receives unscattered light and scattered light traveling away from the substrate. The second polarization filter includes a second polarization axis angularly offset from and not parallel with the first polarization axis. As such, the second polarization filter blocks the advancement of unscattered light while the scattered light is not blocked by the second polarization filter. The hole is detected based on an absence of unscattered light surrounded by light traveling from the second polarization filter.

There is provided a method for inspecting a substrate including: irradiating an illumination light onto a first surface or a second surface opposite to the first surface, of a substrate in which a pattern having a periodicity and extending from the first surface to an inside of the substrate is formed in the first surface, the illumination light having a permeability to permeate the substrate to a predetermined depth; detecting a light reflected from or transmitted through the substrate due to irradiation of the illumination light; and inspecting the substrate by utilizing information based on the periodicity of the pattern obtained from detection of the light reflected from or transmitted through the substrate.

An inspection apparatus and methods for inspecting a body having a structure of walls defining a plurality of channels, such as a honeycomb structure. An inspection apparatus may include a translucent conveyor belt and a light source oriented to direct light onto the backlight surface. The light source and the belt are arranged to convey the body while directing diffuse light into the body, whereby inspection of the inner walls of the structure may be facilitated.

An inspection system includes a thermographic sensor configured to capture thermographic data of a component having holes as a fluid is pulsed toward the holes, and one or more processors configured to temporally process the thermographic data to calculate temporal scores for the corresponding holes, spatially process the thermographic data to calculate spatial scores for the corresponding holes, and calculate composite scores associated with the holes based on the temporal scores and based on the spatial scores. The composite scores represent a likelihood that the corresponding holes are open, blocked or partially blocked.

A plurality of illumination elements configured to irradiate an inspection target region with illumination light obliquely at an identical angle in respective directions different from each other and equiangularly spaced from each other around an image capturing part are sequentially turned on and off. The image capturing part generates a plurality of pieces of captured image data by capturing an image of the target region in a normal direction when each of the plurality of illumination elements is turned on. A determination image generation part generates minimum luminance image data in which a minimum value among luminance values of the plurality of pieces of captured image data at an identical pixel position is set as a luminance value at the pixel position, and then generates determination image data based on the minimum luminance image data. A defect determination part determines existence of a defect based on the determination image data.

A substrate inspection system includes a substrate support, optics configured to irradiate a patterned structure on the substrate and capture images of the patterned structure from light reflected from the patterned structure, a focus adjustment operative to adjust a focal position of the incident light on the patterned structure, and an image processor configured to calculate an optimal value of a focus offset used to establish focal points of the light for defect detection in the patterned structure. The patterned structure may include a first pattern having an opening and a second pattern having top surfaces located at different heights relative to the substrate. The value of the focus offset is determined using images of the top surfaces of the second pattern obtained while changing the focal position of the incident light.

Systems and methods for detecting gaps in netting include constructing a depth map from electromagnetic signals associated with netting surrounding an area, the depth map including measurements of distance of each strand of the netting along an axis perpendicular to a plane formed by the netting relative to the detector. Each segment of netting is identified including each strand of the netting in a side of the netting facing the detector. Locations of gaps in the netting are identified according to the depth map. A user is alerted to the presence and locations of gaps by sending a communication to a computing device.

There is described an inspection device for inspecting a slot of a gas turbine engine. The inspection device comprises: an insert for insertion into the slot; a plurality of imaging devices coupled to the insert; and a processor. The insert is movable along a longitudinal axis of the slot. Each of the plurality of imaging devices is positioned adjacent an external surface of the insert and is configured to capture an image of a portion of the slot adjacent the imaging device. The processor is configured to receive data corresponding to the images captured by the plurality of imaging devices. There is also described a method of inspecting a slot using the inspection device.

A method of examining a cellular structure includes the steps of providing an inspecting device, a neural network and a target cellular structure that includes a plurality of target cells extending therethrough and further includes a target face exposing an arrangement of the target cells; inspecting the arrangement of cells on the face of the target cellular structure using the inspecting device; representing the arrangement of cells with numerically defined target cell parameters; inputting the target cell parameters into the neural network; and generating an output from the neural network based on the target cell parameters, the output being indicative of a strength of the target cellular structure.

In a conductive film, a method of evaluating a pattern in the conductive film, and a display device, thin metal lines of at least one wiring portion of two wiring portions is formed in a wiring pattern where the opening portions, of which angles are maintained and pitches are made to be irregular with respect to rhomboid shapes of a regular rhomboid wiring pattern, have parallelogram shapes. In frequencies of the moirs that are equal to or less than a frequency threshold value and are calculated for each color from two peak frequencies and two peak intensities of 2DFFT spectra of image data of the wiring patterns of the two wiring portions and luminance image data of pixel array patterns of the respective colors at the time of lighting up for each single color, the wiring patterns of the two wiring portions are formed such that an indicator of evaluation of moirs is equal to or less than an evaluation threshold value. The indicator of evaluation is calculated from evaluation values of the moirs of the respective colors obtained by applying human visual response characteristics in accordance with an observation distance to intensities of the moirs equal to or greater than an intensity threshold value.