Mitutoyo Corporation

Mark Lawrence Delaney

Robert Kamil Bryll

Paul Gerard Gladnick

Michael Nahum

Barry Saylor

Yuhua Ding

Vahan A Senekerimyan

Shannon Roy Campbell

Scott Ellis Hemmings

Bjorn Erik Bertil Jansson

Joseph Andrew Summers

Rodney Doe

A workpiece inspection and defect detection system includes a light source configuration, a lens configuration, and a camera configuration for imaging workpieces. The system acquires training and run mode workpiece images for acquiring corresponding sets of training and run mode workpiece image data. Each set of image data includes at least first and second color channel workpiece image data corresponding to first and second color channels (e.g., for which ratios between the first and second color channel workpiece image data may be determined as part of synthetic image data to improve the ability of the system to detect defects). The defect detection portion is trained based at least in part on the image data, and is utilized to perform analysis to determine defect images that include workpieces with defects (e.g., for which metrology operations may be performed for measuring dimensions of defects, etc.).

Workpiece inspection and defect detection system utilizing color channels

A method is provided for operating a tunable acoustic gradient (TAG) lens imaging system. The method includes: (a) providing a smart lighting pulse control routine/circuit (SLPCRC) that provides a first mode of exposure control corresponding to a points from focus (PFF) mode of the TAG lens imaging system and a second mode of exposure control corresponding to an extended depth of focus (EDOF) mode of the TAG lens imaging system; (b) placing a workpiece in a field of view of the TAG lens imaging system; and (c) periodically modulating a focus position of the TAG lens imaging system without macroscopically adjusting the spacing between elements in the TAG lens imaging system, wherein the focus position is periodically modulated over a plurality of focus positions along a focus axis direction in a focus range including a surface height of the workpiece, at a modulation frequency of at least 30 kHz.

High-speed tag lens assisted 3D metrology and extended depth-of-field imaging

A system for providing an automatically focused image comprises an imaging system including a high speed periodically modulated variable focal length (VFL) lens, a VFL lens controller, a VFL-projected light source, a focus determining portion, an exposure timing adjustment circuit, and an exposure strobe time controller. The focus determining portion comprises an optical detector that inputs reflected VFL-projected light that is projected to, and reflected from, a workpiece through the VFL lens, and provides a focus deviation signal. The exposure timing adjustment circuit provides an exposure timing adjustment signal based on the focus deviation signal, which indicates a time when the imaging system focus Z-height approximately coincides with the workpiece surface Z height. The exposure strobe time controller uses the exposure timing adjustment signal to adjust the image exposure time so the imaging system focus Z-height coincides with the workpiece surface Z height at the adjusted image exposure time.

Autofocus system for a high speed periodically modulated variable focal length lens

An image acquisition system is operated to provide an image that is relatively free of the effect of longitudinal chromatic aberration. The system includes a variable focal length lens (e.g., a tunable acoustic gradient index of refraction lens) that is operated to periodically modulate a focus position. First, second, third, etc., wavelength image exposure contributions are provided by operating an illumination system to provide instances of strobed illumination of first, second, third, etc., wavelengths (e.g., green, blue, red, etc.) timed to correspond with respective phase timings of the periodically modulated focus position which focus the respective wavelength image exposure contributions at the same focus plane. The respective phase timings of the periodically modulated focus position compensate for longitudinal chromatic aberration of at least the variable focal length lens. An image is produced that is relatively free of the effect of longitudinal chromatic aberration by combining the image exposure contributions.

Chromatic aberration correction in imaging system including variable focal length lens

A method improves focus height repeatability in a machine vision inspection system. A region of interest is defined within a field of view imaged by a camera portion, wherein an aligned edge feature in the region of interest may introduce a focus height sensitivity that varies depending on the aligned edge feature offset relative to the image pixels. A first set of focus-determining operations determines a focus height for the region of interest, and comprise at least one of: (a) operations that reduce the sensitivity of the focus height determination to the offset of the aligned edge feature relative to the image pixels; and (b) operations that adjust the offset of the aligned edge feature relative to the image pixels according to a predetermined offset repeatability criteria, such that the image data used in the focus height determination fulfills the offset repeatability criteria.

Focus height repeatability improvement in a machine vision inspection system

A method for controlling a structured illumination pattern generating portion is provided for illuminating a workpiece during an image acquisition by a camera in a precision machine vision inspection system. A controllable spatial light modulator (e.g., a digital light processing projector) is part of the generating portion for generating the structured illumination pattern. The pattern may comprise an array of stripes including a sinusoidal gray level intensity variation across each stripe. An overall image exposure is increased by repeating a complete structured illumination pattern generation iteration, including gray level variation, a plurality of times during an image integration period. Structured illumination microscopy techniques for determining a workpiece surface profile may benefit, wherein multiple (e.g., 3 or 4) images are acquired at respective focus positions to be analyzed, by using the method to project a different phase of a structured light pattern for each of the multiple images.

Structured illumination projection with enhanced exposure control

The repeatability of strobe illumination for image exposure is improved over a wide dynamic range in a machine vision system wherein a relationship between a camera integration period and a pulse duration of a strobe light generator control the effective exposure of a camera image during a timing overlap between a beginning of the camera integration period and an end of the pulse duration. To avoid noise in the illumination, the illumination pulse duration may start, the camera integration period may begin after a delay relative to that start and not later than the end of the pulse duration, the pulse duration may end, and the camera integration period may end not earlier than the end of the pulse duration. The timing overlap may also be synchronized with a periodic ripple component in the strobe illumination, to provide improved repeatability.

Systems and methods for controlling strobe illumination

A user interface for setting parameters for an edge location video tool is provided. In one implementation, the user interface includes a multi-dimensional parameter space representation with edge zones that allows a user to adjust a single parameter combination indicator in a zone in order to adjust multiple edge detection parameters for detecting a corresponding edge. The edge zones indicate the edge features that are detectable when the parameter combination indicator is placed within the edge zones. In another implementation, representations of multiple edge features that are detectable by different possible combinations of the edge detection parameters are automatically provided in one or more windows. When a user selects one of the edge feature representation, the corresponding combination of edge detection parameters is set as the parameters for the edge location video tool.

Edge measurement video tool and interface including automatic parameter set alternatives

In a machine vision system editing environment for a part program, a continuous stream of image acquisition operations are performed during a run mode. Previously, a continuous stream of image acquisition operations was achieved by utilizing different programming representations and syntax for programming and grouping image acquisition operations together in the part program. A new common syntax and representations are utilized wherein such continuous image acquisition operations are recorded in the same way as regular operations, with the running of the part program being performed in two stages. First, the portion of the part program that is to have the continuous stream of image acquisition is scanned for image acquisition operations, and the most efficient order for acquiring the images is determined. Second, while the image acquisition process is being performed, the portion of the part program is scanned again, with the image analysis operations then being performed.

Machine vision system editing environment for a part program in which a continuous stream of image acquisition operations are performed during a run mode

A method utilizing image correlation to determine position measurements in a machine vision system. In a first operating state, the machine vision system utilizes traditional scale-based techniques to determine position measurements, while in a second operating state, image correlation displacement sensing techniques are utilized to determine position measurements. The image correlation techniques provide for higher accuracy for measuring distances between features that are separated by more than one field of view. The user may toggle between the operating states through a selection on the user interface, and guidance may be provided regarding when the image correlation mode is likely to provide higher accuracy, depending on factors such as the distance to be measured and the characteristics of the surface being measured.

Method utilizing image correlation to determine position measurements in a machine vision system

A machine vision inspection system comprises an optical portion providing an image of a field of view of a workpiece which may be a magnified image. A first camera and a second camera provide first and second images of a shared or common field of view of the workpiece and are arranged such that the orientation of the common field of view imaged in the first camera is rotated relative to the orientation of the common field of view imaged in the second camera. Signal processing provides an edge measurement of an edge feature within the common field of view and determines which of the first and second images is used as a basis for the edge measurement based on whether their respective edge orientation (with respect to the pixel array of each camera) differs from the pixel array orientation of their associated camera by an orientation difference threshold amount.

Machine vision inspection system comprising two cameras having a rotational offset

A machine vision system editing environment is provided for a part program in which a continuous stream of image acquisition operations are performed during a run mode. In one embodiment, a new common syntax and representations are utilized wherein continuous image acquisition operations are recorded in the same way as regular operations, with the running of the part program being performed in two stages. In the first stage, the portion of the part program that is to have the continuous stream of image acquisition is scanned for image acquisition operations, and the most efficient order for acquiring the images is determined, after which the image acquisition process is begun. Then, in the second stage, while the image acquisition process is being performed, the portion of the part program is scanned again, with the image analysis operations then being performed.

A user interface for setting parameters for an edge location video tool is provided. The user interface includes a multi-dimensional parameter space representation that allows a user to adjust a single parameter combination indicator in order to adjust multiple edge detection parameters at once. One or more edge feature representation windows may be provided which indicate the edge features detectable by the current configuration of the edge detection parameters.

Edge measurement video tool parameter-setting user interface

A method is disclosed for operating a machine vision inspection system to determine a fluorescent imaging height for acquiring a fluorescent image for repeatably determining the location of a feature within the fluorescent material. The height of an exposed workpiece portion exposed outside of the fluorescent material is determined (e.g., using a height sensor or autofocus operations). The determined height is repeatable. The exposed portion has a characteristic height relative to the fluorescent material and/or features located therein. The fluorescent imaging height, which may be inside the fluorescent material, is determined relative to the determined height of the exposed portion. The fluorescent imaging height is determined such that it enhances the detection of the desired feature located within the fluorescent material in the resulting fluorescent image. For a variety of workpieces, the method provides automatic acquisition of appropriately focused fluorescent image more reliably than previously known methods.

Precision solder resist registration inspection method

A system and method for correcting surface height measurements for optical aberration is provided. Heights determined by an autofocus tool, which may depend on surface feature angles in a focus region of interest (ROI) and on the ROI location in the field of view, are corrected based on a novel error calibration. Error calibration data includes height corrections for different feature angles in images, and for multiple locations in a field of view. Height corrections are determined by weighting and combining the angle dependent error calibration data, e.g., based on a gradient (edge) angle distribution determined in the ROIs. When Z-heights are determined for multiple ROIs in a field of view, storage of image data from particular images of a global image stack may be efficiently controlled based on determining early in processing whether a particular image is a sufficiently focused 'near-peak' focused image or not.

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Shoreline, WA, United States of America

Mark Lawrence Delaney