Agfa Corporation

Illinois Tool Works Inc.

Bayer Corporation -- Agfa Division

Agfa Division, Bayer Corporation

Dimensional Photonics International, Inc.

Roy D Allen

Frank Lynn Scholten

Stephen Michael McMahon

David Joel Romano

Neil Judell

Robert F Dillon

Martin Allen Peterson

Yi Qian

Christian J Hoehl

Bryan Comeau

Dwayne Bailey

Zachary Harvey

Stephen C Hinds

Mark A Ritter

This disclosure relates to methods and tools for calibrating a camera-based three-dimensional optical metrology system such as that used for non-contact measurement of strain in a materials test system. A tool is provided which holds a calibration plate within a test space of a load frame of a materials testing device. The tool includes a spindle which rotates around a rotational axis to a series of detent rotational positions. The spindle engages the calibration plate by a bearing configuration which allows the tilt angle of the calibration plate to be varied. The rotation of the spindle and the variation of the tilt angle provides for two degrees of freedom of movement within the test space. The resulting sequence of calibration plate positions is systematic and repeatable.

Three-dimensional calibration tools and methods

This disclosure relates to method of enhancing the three-dimensional detection range of a vision-based, single camera intrusion detection system within a tensile test machine or other materials testing machine. Illumination sources are offset from the camera and provide a cones of illumination which intersect with the conical viewing zone of the camera thereby defining a detection zone. When objects intrude into these conical regions, a shadow is cast. The shadow is detected by the camera. The detection of the intrusion is typically used as a safety function to deactivate at least part of the function of the materials testing machine.

Method of increasing detection zone of a shadow-based video intrusion detection system

The present disclosure provides an apparatus and method which uses a field splitter or a beam splitter for the purpose combining two different views of a materials testing sample under materials testing into a single image. This allows for three-dimensional strain measurement in the context of material/compound testing. In particular, the time and stress dependent change in gauge length can be tracked and calculated in order to calculate the time and stress dependent strain. The method and apparatus allows imaging on a single image sensor for the three-dimensional strain calculation.

Field splitter for three-dimensional strain measurement

This disclosure presents a method of measuring the strain response of a test material remotely by optical devices using a thin multi-layer assembly, called an optical strain gauge, which is attached directly to the test specimen by pair of adhesive patches built into the assembly. The optical strain gauge assembly attaches quickly and easily by just pressing it onto the specimen by virtue of the two pressure-activated adhesive patches. There is typically no surface preparation necessary for the test specimen. The spatial separation between the two patches adhered to the specimen surface serves to establish an initial gauge length for calculating strain by measuring the stress induced changes to this separation when a load is applied to the test specimen.

Optical strain gauge

The disclosure relates to a remote displacement sensor, such as an optical strain gauge, which uses an optical amplifier implemented by patterns, such as, moir&#xe9; patterns, to calculate changes in position. In a strain gauge with moir&#xe9; patterns, two foil layers are provided, a lower foil layer with a reference or static moir&#xe9; pattern generated by the overlaying of a first pattern with parallel lines at a first fundamental frequency and a second pattern with parallel lines at a second fundamental frequency. The lower foil layer further includes a first section with a first pattern with parallel lines at the first fundamental frequency while the upper layer provides a second section with a second pattern with parallel lines at the second fundamental frequency. The overlaying of the foils causes an overlying of the first and second sections thereby causing a moir&#xe9; pattern of the same wavelength as the reference pattern.

Remote displacement sensor, including an optical strain gauge, an assembly and system therewith

Described is an interferometric surface contour measurement system for projecting structured light patterns onto an object. The measurement system includes an interferometric projector, an imager, and a processor. The imager is rigidly coupled to the projector to maintain a stable relationship to the projected, structured light pattern. The imager receives the structured light pattern and together with the processor, determines whether the projected image includes a positional error. In some embodiments, the projector is a multi-channel projector, each channel having an optical axis spatially separated from the others, one of the channels including the imager and dedicated for determining positional error. In other embodiments, the projector is a single-channel projector projecting a structured light pattern onto the object, a portion of the structured light pattern being tapped-off for determining positional error.

Determining positional error of an optical component using structured light patterns

A visual sensor includes a reference portion comprising an image independent of banding and a banding test portion adjacent to the reference portion comprising an image sensitive to banding. In one embodiment, the visual sensor also includes a process check portion adjacent to the banding portion for indicating whether a predetermined imaging parameter is within designated limits.

Method and apparatus for display of banding

A calibration system for a platesetter or imagesetter is applicable to systems that have a media drum and a carriage, including a light source and a spatial light modulator for selectively exposing the media that is held against the drum. The invention can be applied to internal or external drum systems. The calibration system comprises a calibration sensor that is scanned relative to the spatial light modulator. The controller then analyzes the response of the calibration sensor to generate calibration information that is used to configure the spatial light modulator. The use of this calibration sensor allows for job-to-job calibration of the spatial light modulator, in one example, that ensures; the generation of a high quality images, without banding, for example, on the media. This calibration system is also used to detect a best focus position for projection optics by measuring a contrast ratio between exposure and dark levels for various focus settings. It selects the best focus position in response to the contrast ratio.

Method and system for focus control in imaging engine with spatial light modulator

A visual sensor has a first portion and a second portion. The sensor is able to detect the state of one or more imaging parameters such as exposure setting, pulse width modulation, focus, balance, spot ellipticity, sidelobe size, shape, and intensity, media gamma, edge sharpness, dot gain, uniformity, ink receptivity, physical changes in the media, pattern dependent effects such as dot gain or tone resolution compared to the type of halftone used, and sensitivity to calibrated position or exposure errors. The first image portion has a first imaging characteristic, and the second image portion has a second imaging characteristic. Imaging characteristics are characteristics of an image, including, but not limited to apparent density level, tint, color, reflectivity, absorption, granularity or microstructure, size, shape, distribution, degree of randomness, structure, edge sharpness, and depth or dimension. One of the portions is less sensitive to one or more imaging parameters than the other portion so that the first image portion and the second image portion appear substantially similar at a desired range of imaging parameters, and appear different otherwise. The imaging characteristic of the first portion is distinguishable from the imaging characteristic of the second portion for one or more ranges of one or more imaging parameters, and is not distinguishable for the alternate range(s) of the one or more imaging parameters. A range can be a particular imaging parameter value, or a range that excludes one or more imaging parameter values.

Method and apparatus for display of imaging parameters

A system and method for detecting imaging parameters includes forming a first image generated with pseudorandom noise and a second image generated with the same pseudorandom noise that serve as an imaging parameter sensor when the first and second images are superimposed. The sensor is useful for visually detecting such imaging parameters such as geometric errors. In one embodiment, the first and second patterns are generated with pseudorandom noise by modulating a repetitive pattern with pseudorandom noise. In another embodiment, the first and second patterns are generated with pseudorandom noise by forming a pseudorandom image and the reverse of the image, and phase shifting one or both of the images.

Imaging parameter detection

A beam scanning system for scanning an imaging surface includes a phase shifter for issuing phase signals, a radiation emitter for emitting a beam of radiation and a deflection element, such as an acousto-optic modulator or translating lens, for deflecting the radiation beam. Depending on the implementation, the emitter can be configured to phase shift the radiation beam and/or the deflection element can be configured to deflect the radiation beam in accordance with the issued phase signals. By emitting and/or deflecting the radiation beam in accordance with the phase signals, the length of the scan line formed on the imaging surface can be controlled. A deflector, such as a spin mirror or rotatable prism, is provided to direct the radiation beam to form a scan line on the imaging surface.

Optical scanning with phase shifted beam

A method for detecting image position errors, includes forming a first pattern with a symbol embedded therein and a second pattern which, when superpositioned on the first pattern, exposes the symbol if the misalignment between the first and second patterns exceeds a position error tolerance. The symbol is perceivable with the unaided eye even if the misalignment is imperceivable to the unaided eye.

Image position error detection technique using parallel lines and

A multi-beam scanning system for scanning a curved imaging surface includes at least one radiation emitter which emits first and second beams of radiation. A spin deflector, rotatable about a spin axis, directs the first beam to form a first scan line and the second beam to form a second scan line on the imaging surface. A deflection element, disposed in the path of the first beam and upstream of the spin deflector, operates to deflect the first beam with respect to the rotation of the spin deflector. The spin deflector is impinged by beams of radiation only at a distance, other than zero, from the spin axis.

Scanner with deflection element for scanning imaging surfaces

A multibeam scanning system for scanning an imaging surface, includes at least one radiation emitter configured to emit a first beam of radiation and a second beam of radiation. A spin deflector, rotatable about a spin axis, is provided to direct the first beam to form a first scan line and the second beam to form a second scan line on the imaging surface. At least one moving element, such as a translating lens, disposed upstream of said spin deflector, operates to deflect at least one of the beams with respect to the spin axis of the spin deflector.

Growing community of inventors

Burlington, MA, United States of America

Roy D Allen