431 results about "Grating pattern" patented technology

A non-contact three-dimensional surface measurement method is provided in which a grating pattern projected onto an object being measured, while the phase of the pattern is being shifted, is observed in a different direction from a projection direction to analyze the contrast of a grating image deformed in accordance with the shape of the object and thereby obtain the shape thereof. The method enables measurement of a three-dimensional shape over a large measurement range in a short time in a non-contact manner by successively shifting the focus on the projection and the imaging sides to enlarge the measurement range in the direction of depth.

The invention discloses a fringe projection time phase unwrapping method based on deep learning. Firstly, four sets of three-step phase shift grating patterns are projected to a to-be-tested object, the frequencies are 1, 8, 32 and 64 respectively, and a camera collects a raster image and obtains a wrapped phase image by using a three-step phase shift method; then, a multi-frequency algorithm based on time phase unwrapping is used for carrying out phase unwrapping on the wrapped phase image to obtain a periodic level map of a phase with the frequency of 64; a residual convolutional neural network is constructed; the input data is set to be the wrapped phase image with the frequencies of 1 and 64, and the output data is the periodic level map of the phase with the frequency of 64; finally,a training set and a verification set are made to train and verify the network; and the network verifies a test set to output the periodic level map of the phase with the frequency of 64. According tothe fringe projection time phase unwrapping method based on deep learning in the invention, the deep learning method is adopted and the wrapped phase image with the frequency of 1 is used for unwrapping the wrapped phase image with the frequency of 64; and an absolute phase image with less error points and higher accuracy can be obtained.

A method and apparatus for determining optical mask corrections for photolithography. A plurality of grating patterns is printed onto a wafer utilizing a photomask having at least one grating. Each grating pattern within the plurality of grating patterns is associated with known photolithographic settings. Each grating pattern is illuminated independently with a light source, so that light is diffracted off each grating pattern. The diffracted light is measured utilizing scatterometry techniques to determine measured diffracted values. The measured diffracted values are compared to values in a library to determine a profile match. A 2-dimensional profile description is assigned to each grating pattern based on the profile match. A database is compiled of the profile descriptions for the plurality of grating patterns. Photomask design rules are then generated by accessing the database containing the 2-dimensional profile descriptions. In preferred embodiments, the design rules are used to create and correct masks containing OPC corrections, phase-shifting mask corrections and binary masks. In a preferred embodiment the at least one grating is a bi-periodic grating. In a preferred embodiment, the scatterometry technique is optical digital profilometry utilizing a reflectometer or ellipsometer.

The invention discloses a radiological image detection apparatus, a radiographic apparatus and a radiographic system. The radiological image detection apparatus includes a first grating unit, a grating pattern unit, a radiological image detector, and an anti-scatter grating. The grating pattern unit has a period that substantially coincides with a pattern period of a radiological image formed by radiation having passed through the first grating unit. The radiological image detector detects the radiological image masked by the grating pattern unit. The anti-scatter grating is arranged on a path of the radiation incident onto the radiological image detector and removes scattered radiation. A smoothing process is performed for at least one of a surface and a backside of the anti-scatter grating intersecting with a traveling direction of the radiation.