3m Innovative Properties Company

Minnesota Mining and Manufacturing Company

Christopher R Yungers

David H Redinger

Jennifer Frances Schumacher

Subhalakshmi M Falknor

Eric M Chinnock

Michael E Griffin

John Allen Wheatley

Ronald David Jesme

Casey L Carlson

William Bedingham

Scott D Pearson

Jon A Kirschhoffer

Guanglei Du

Justin M Johnson

Hatim M Carim

Thomas A Turgeon

John W Frank

Jonathan Dale Gandrud

Vinod P Menon

James Hillis

Craig D Oster

David J Colburn

Nathan A Christopherson

At least some embodiments of the present disclosure directs to a method for processing an input image having an embedded element, comprising the steps of: computing one or more histograms of the input image; identifying a range of interest in one of the one or more histograms; and determining, by the processor, a threshold based on the range of interest. In some embodiments, a computing device processes the input image using the threshold to generate an output image.

Apparatus and methods for preprocessing images having elements of interest

A technique may include applying a first electrical signal to a first pair of drive electrodes, and, while applying the first electrical signal to the first pair of drive electrodes, determining a first measured voltage using a first measurement electrode. The technique further may include applying a second electrical signal to a second pair of drive electrodes, and, while applying the second electrical signal to the second pair of drive electrodes, determining a second measured voltage using a second, different measurement electrode. The first pair of drive electrodes, the second pair of drive electrodes, the first measurement electrode, and the second, different measurement electrode may from a set of N electrodes electrically coupled to the material. The technique also may include determining whether the material includes a crack or other defect based on a comparison between the first measured voltage and the second measured voltage.

Electrode placement for verifying structural integrity of materials

The disclosure describes techniques for detecting a crack or defect in a material. The technique may include applying an electrical signal to a first electrode pair electrically coupled to the material. The technique also may include, while applying the electrical signal to the first electrode pair, determining a measured voltage between a second, different electrode pair. At least one electrode of the second, different electrode pair is electrically coupled to the material. The technique may further include determining a corrected measured voltage by suppressing a thermally induced voltage from the measured voltage and determining whether the material includes a crack or other defect based on the corrected measured voltage.

Suppressing thermally induced voltages for verifying structural integrity of materials

An armor piece may include a tested material. The armor piece also may include a plurality of electrical contacts distributed about and electrically connected to the tested material. The armor piece further may include a non-volatile memory (NVM) device. The NVM device may be hardened against exposure to x-ray radiation. The NVM device may be configured to store control voltages associated with respective electrical contacts of the plurality of electrical contacts.

Verifying structural integrity of materials

A measurement system may include control electronics; an electrical signal source; a plurality of measurement system electrical contacts; at least one feature for repeatably electrically connecting the plurality of measurement system electrical contacts to selected locations of a tested material. The control electronics may be configured to cause the electrical signal source to output an electrical signal; determine a measured voltage in response to the electrical signal using a measurement electrical contact from the plurality of measurement system electrical contacts. The measurement electrical contact is electrically coupled to the tested material. The control electronics also may be configured to determine whether the tested material includes a crack or other defect based on the measured voltage.

Systems and methods for detecting a crack or defect in a material are described. An example method may include determining, by a computing device, for each respective adjacent pair of electrodes of a plurality of electrodes electrically coupled to the material, a respective electrode pair voltage. The method also may include determining, by the computing device, for each respective adjacent pair of electrodes, a respective temperature-corrected electrode pair value based on the respective electrode pair voltage and at least one of a respective control voltage associated with the respective adjacent pair of electrodes or a temperature correction factor. The method may further include determining, by the computing device, whether the material includes a crack or defect based on the plurality of respective temperature-corrected electrode pair values.

Temperature-independent verifying of structural integrity of materials using electrical properties

A measurement system may include an electrical signal source; a plurality of electrical contacts electrically coupled to a tested material; a respective resistor associated with each electrical contact; a common node to which the respective resistors are electrically connected; and a control module. The control module may cause the electrical signal source to be electrically connected to a selected electrical contact as an input electrical contact. The remaining electrical contacts are electrically connected to a return node of the electrical signal source as extraction electrical contacts. The control module also may cause the electrical signal source to output an electrical signal to an input electrical contact; cause a respective electrical signal parameter to be determined at the respective resistor associated with each respective extraction electrical contact; and determine whether the tested material includes a crack or other defect based on the respective electrical signal parameters.

Verifying structural integrity of materials using electrical properties

A method may include coupling a first electrical connector of an article to a second electrical connector of a measurement device. The article may include a tested material, the first electrical connector, and a plurality of electrical contacts electrically connected to the first electrical connector. The measurement device may include a power source and a user interface. The method also may include causing, by a controller, an electrical signal to be applied to a pair of drive electrical contacts from the plurality of electrical contacts. The method further may include receiving, by the controller, from an analog-to-digital converter, a measured voltage measured using a measurement electrical contact from the plurality of electrical contacts. The method also may include determining, by the controller, whether the tested material includes a crack or other defect based on the measured voltage.

A measurement system may include a set of drive electrical contacts including a force electrical contact and a return electrical contact electrically coupled to a tested material, a measurement electrical contact electrically coupled to the tested material, a return node, a voltage source, and a control module. A circuit path between the voltage source and the return node may include a fixed resistor and the tested material. The control module may be configured to cause the voltage source to apply a voltage signal to the force electrical contact, cause a voltage drop across the fixed resistor to be measured, cause a measured voltage to be measured using the measurement electrical contact, determine a measured equivalent impedance of the tested material associated with the measurement electrical contact based on the voltage drop across the fixed resistor and the measured voltage, and determine whether the tested material includes a crack or other defect based on the measured equivalent impedance.

Verifying structural integrity of materials using reference impedance

Optical systems are described that include a switchable diffuser, a display panel, a lighting component and a diffuser controller. The diffuser controller is configured to switch the state of the switchable diffuser when the diffuser controller determines that the diffuser state is to be changed. The diffuser controller may be configured to vary an output level of the display panel in association with a change in state of the switchable diffuser. The optical system may also include a switching device which may be separable from the display panel.

Variable viewing angle optical systems

A biomedical sensor system. The system can include a sensor adapted to create a signal based on a physiological characteristic from a subject, and a hub adapted to receive the signal from the sensor. The signal can include at least one of an electromagnetic signal, an electrical signal, an acoustic signal, a mechanical signal, a thermal signal, and a chemical signal. The system can further include a connector adapted to couple the sensor and the hub, the connector having a variable length, such that the sensor and the hub can be positioned a variable distance apart by changing the length of the connector. The connector can be adapted to provide a pathway between the sensor and the hub for the signal. A method of applying a biomedical sensor system to a subject can include changing the length of the variable-length connector to provide an appropriate distance between the sensor and the hub, and coupling the sensor to the subject.

Biomedical sensor system

The invention relates to a volumetrically efficient solenoid antenna fabricated on or within a substrate, such as a printed circuit board. The antenna may be used in many applications requiring a short-range wireless communication or sensing link, such as RFID systems, badge readers, contactless connectors, proximity sensors, and short-range data links. The antenna may be, for example, fabricated on or within a printed circuit board of an RFID reader, thereby enabling a perpendicular orientation of the RFID reader with respect to the z-axis of an RFID tag, where the x-y axes are the length and width of the tag. This perpendicular orientation enables the user to point or aim the RFID reader directly at the RFID tag for efficient information transfer between the reader and a single tag in a multiple tag environment.

Growing community of inventors

Saint Paul, MN, United States of America

Christopher R Yungers