Cognex Corporation

Esther Oteo Lozano

Laurens Nunnink

Jose Fernandez Dorado

Ivan A Bachelder

Andreas Weber

Chen Gao

Francisco Azcona Guerrero

Richard Reuter

Matthew D Engle

Pablo Garcia Campos

Carl W Gerst

Rene Delasauce

Nicole Dippel

Tony Depre

This invention provides a system and method for detecting and acquiring one or more in-focus images of one or more barcodes within the field of view of an imaging device. A measurement process measures depth-of-field of barcode detection. A plurality of nominal coarse focus settings of a variable lens allow sampling, in steps, of a lens adjustment range corresponding to allowable distances between the one or more barcodes and the image sensor, so that a step size of the sampling is less than a fraction of the depth-of-field of barcode detection. An acquisition process acquires a nominal coarse focus image for each nominal coarse focus setting. A barcode detection process detects one or more barcode-like regions and respective likelihoods. A fine focus process fine-adjusts, for each high-likelihood barcode, the variable lens near a location of the barcode-like regions. The process acquires an image for decoding using the fine adjusted setting.

System and method for auto-focusing a vision system camera on barcodes

This invention provides a system and method for enhanced depth of field (DOF) advantageously used in logistics applications, scanning for features and ID codes on objects. It effectively combines a vision system, a glass lens designed for on-axis and Scheimpflug configurations, a variable lens and a mechanical system to adapt the lens to the different configurations without detaching the optics. The optics can be steerable, which allows it to adjust between variable angles so as to optimize the viewing angle to optimize DOF for the object in a Scheimpflug configuration. One, or a plurality, of images can be acquired of the object at one, or differing angle settings, with the entire region of interest clearly imaged. In another implementation, the optical path can include a steerable mirror and a folding mirror overlying the region of interest, which allows different multiple images to be acquired at different locations on the object.

System and method for extending depth of field for 2D vision system cameras in the presence of moving objects

This invention provides an illumination assembly that is typically attached to the front end of a vision system camera assembly, adapted to generate an illumination pattern onto an object, which allows the vision system process(or) to perform basic shape inspection of the object in addition to feature detection and decoding. A dome illuminator with a diffuse inner surface is provided to the camera assembly with a sufficient opening side to surround the object. The dome illuminator has two systems to create the pattern on an object, including a diffuse illuminator for specular/shiny object surfaces and a secondary, projecting illuminator for matte/diffusive object surfaces. The diffuse illuminator includes a set of light-filtering structures on its inner surface&#x2014;for example concentric strips or rings that allow projection of a ringed fringe pattern on an (e.g. shiny/specular) object. The fringes can additionally be generated in a given a certain wavelength and/or visible color.

Dome illuminator for vision system camera and method for using the same

This invention provides a vision system that is arranged to compensate for optical drift that can occur in certain variable lens assemblies, including, but not limited to, liquid lens arrangements. The system includes an image sensor operatively connected to a vision system processor, and a variable lens assembly that is controlled (e.g. by the vision processor or another range-determining device) to vary a focal distance thereof. A positive lens assembly is configured to weaken an effect of the variable lens assembly over a predetermined operational range of the object from the positive lens assembly. The variable lens assembly is located adjacent to a front or rear focal point of the positive lens. The variable lens assembly illustratively comprises a liquid lens assembly that can be inherently variable over approximately 20 diopter. In an embodiment, the lens barrel has a C-mount lens base.

System and method for reduction of drift in a vision system variable lens

This invention provides a single-camera vision system, typically for use in logistics applications, that allows for adjustment of the camera viewing angle to accommodate a wide range of object heights and associated widths moving relative to an imaged scene with constant magnification. The camera assembly employs an image sensor that is more particularly suited to such applications, with an aspect (height-to-width) ratio of approximately 1:4 to 1:8. The camera assembly includes a distance sensor to determine the distance to the top of each object. The camera assembly employs a zoom lens that can change at relatively high speed (e.g. &#x3c;10 ms) to allow adjustment of the viewing angle from object to object as each one passes under the camera's field of view (FOV). Optics that allow the image to be resolved on the image sensor within the desired range of viewing angles are provided in the camera lens assembly.

Single camera vision system for logistics applications

A vision system for imaging feature sets on an object surface, including a first imaging system having at least a first image sensor and first optics, the first imaging system defining a standard, on-axis configuration having a system optical axis. A second imaging system defines an extended-depth of focus (DOF) configuration with second optics. A vision system processor receives and processes image data from the first imaging system and the second imaging system. A primary aimer assembly and a secondary aimer assembly that each project a discrete beam of structured light onto the surface in a relative relationship that indicates a focus distance with respect to the first imaging system and indicates an approximate center of the field of view of the second imaging system.

Vision imaging system having a camera and dual aimer assemblies

This invention provides a vision system, typically having at least two imaging systems/image sensors that enable a multi-function unit. The first imaging system, typically a standard, on-axis optical configuration can be used for long distances and larger feature sets and the second imaging system is typically an extended-depth of focus/field (DOF) configuration. This second imaging system allows reading of smaller feature sets/objects and/or at shorter distances. The reading range of an overall (e.g.) ID-code-reading vison system is extended and relatively small objects can be accurately imaged. The extended-DOF imaging system sensor can be positioned with its longest dimension in the vertical axis. The system can allow vision system processes to compute the distance from the vision system to the object to generate an autofocus setting for variable optics in the standard imaging system. An aimer can project structured light onto the object surface around the system optical axis.

Dual-imaging vision system camera and method for using the same

This invention provides a vision system camera assembly that includes an optics and illumination module that is removably attached thereto, and that is arranged to project illumination along an optical axis of the imager. This arrangement allows for short exposure time and a short working distance from an imaged scene/surface under inspection. A semi-reflecting mirror turns a structured illumination beam from an illumination axis onto the optical axis while allowing light from the imaged scene to pass through the mirror and into the imager optics. The front end of the module contains a collimating optics that causes a collimated beam from the mirror to strike the surface at various off-axis angles. The collimating optics can include a telecentric lens assembly that can comprise a pair of stacked lenses having a perimeter that is equal to or greater than the area of interest on the surface.

System and method for acquiring images of surface texture

This invention overcomes disadvantages of the prior art by providing, vision system, typically in the form of a handheld ID reader, which can include two imaging systems, a first imaging system that is off-axis and a second imaging system that is on-axis. The on-axis imaging system is typically standard in configuration, and can be used, for example, with a polarized illumination system. The off-axis imaging system is intended to minimize the camera reflection footprint on a (typically rounded) shiny object to enhance reading of small feature sets (e.g. DMP codes). The off-axis imaging system includes a diffusive illumination source with an emitter in the form of a concave surface, such as a semi-cylinder or dome. Combining images from the two imaging systems allows the contrast of the imaged feature set to be optimized, and provide superior reading and decoding of small codes on shiny rounded surfaces&#x2014;such as DPM codes.

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Aachen, Germany

Esther Oteo Lozano