Patent ID: 8534113
Filing Date: 2013-09-17
Classification: G01B

Abstract:
1. A method for providing Z-height error calibration data usable to correct Z-height measurements determined by a machine vision inspection system, the method comprising: (a) positioning a focus region of interest used for calibration at a calibration location in a field of view of the machine vision inspection system; (b) providing anisotropic image content used for calibration; (c) positioning the anisotropic image content in the focus region of interest used for calibration; (d) providing a variation in an orientation angle of the anisotropic image content in the focus region of interest used for calibration; (e) determining Z-height measurement results based on the focus region of interest used for calibration, the Z-height measurement results including a variation in relation to the variation in the orientation angle of the anisotropic image content in the focus region of interest used for calibration; (f) determining Z-height error calibration data corresponding to the corresponding calibration location in a field of view, the Z-height error calibration data including a characterization of the variation in Z-height measurement results, in relation to a variation in the orientation angle of the anisotropic image content in the focus region of interest used for calibration; and (g) storing the Z-height error calibration data corresponding to the corresponding calibration location in a field of view in a storage medium accessible by the machine vision inspection system.