Use of scattered and/or transmitted light in determining characteristics, including dimensional information, of object such as part of flat-panel display
Scattered or/and transmitted light is employed to determine characteristics, including dimensional information, of an object (60) such as part (10) of a flat-panel display. The dimensional information includes the average diameter of openings (62) in the object, the average density of the openings, and the average thickness of a layer (64) of the object. Light-diffraction patterns are produced to determine characteristics, such as abnormalities (146 and 148), of crossing lines (140 and 142) in such an object.
A method and system for performing sequence time domain reflectometry over a communication channel to determine the location of line anomalies in the communication channel is disclosed. In one embodiment, the system generates a sequence signal and transmits the sequence signal over an optical channel. The system receives one or more reflection signals over the optical channel and performs reflection signal processing on the reflection signal. In one embodiment, the optical reflection is transformed to an electrical signal and correlated with the original sequence signal to generate a correlated signal. The time between the start of the reflection signal and a subsequent point of correlation and the rate of propagation reveals a line anomaly location. In one or more embodiments sequence signal time domain reflectometry occurs during data transmission.
