Seek Thermal, Inc.

Jason Wolfe

Ross Williams

William J Parrish

Andreas Engberg

Blake Henry

Derek Moran

Russ Mead

Romeo Chahine

Brian Nehring

Jeffery Lee

Willliam J Parrish

An ultra-small thermal imaging core, or micro-core. The design of the micro-core may include substrates for mounting optics and electronic connectors that are thermally matched to the imaging Focal Plane Array (FPA). Test fixtures for test and adjustment that allow for operation and image acquisition of multiple cores may also be provided. Tooling may be included to position the optics to set the core focus, either by moving the lens and lens holder as one or by pushing and/or pulling the lens against a lens positioning element within the lens holder, while observing a scene. Test procedures and fixtures that allow for full temperature calibration of each individual core, as well as providing data useful for uniformity correction during operation may also be included as part of the test and manufacture of the core.

Design, test, and operation of a small thermal imaging core

Systems and methods may be provided that improve the application of Histogram Equalization (HE) transfer functions for converting image system source data to display compatible image frames. Histograms developed from source data may be measured and depending on their properties, the gain of the HE transfer function may be adaptively adjusted. In some embodiments the property measured is a histogram width.

Adaptive gain adjustment for histogram equalization in an imaging system

A thermography process for thermal imaging systems produced in quantity, including an imaging sensor and an ambient temperature sensor, that includes operations at three different places in the manufacture and actual use of the system. A temperature calibration may be performed on all units of a given design at a small number of controlled scene temperatures at one ambient temperature to produce a function that relates sensor signal to scene temperature. The function is determined for each individual unit and may be unique for each unit. Selected calibrated units may be subjected to a qualification test where they are exposed to larger number of controlled scene temperatures at a plurality of controlled ambient temperatures and the errors between the calibration derived function and the observed results and/or the actual scene temperatures at the various scene/ambient temperature combinations may be derived and put into a table that is loaded into all production units. In actual use of the imaging system, for any given actual observed signal and temperature sensor values, the corresponding scene temperature and/or error may be derived from the table and used to modify the temperature value from the calibration function.

Thermography process for converting signal to temperature in a thermal imaging system

An imaging system whose Field of View FOV experiences occasional motion in relation to viewed scenes may be configured to reduce Fixed Pattern Noise (FPN) of acquired image data. FPN may be reduced by developing a pixel by pixel FPN correction term through a series of steps including blurring the image, identifying pixels to exclude from some calculations, a motion detector and an FPN updater for frames under motion and an FPN decay element for frames that are still.

Fixed pattern noise mitigation for a thermal imaging system

Systems and methods for allocating display colors to thermal image intensity data acquired by thermal band photodetectors. Intensity data from the photodetectors corresponding to scene temperature is converted to a digital value within an analog to digital conversion (ADC) range. The full ADC range may be divided into two or more sub-ranges. In one sub-range, intensity values within that sub-range are assigned display colors from a first color table utilizing one or more Histogram Equalization (HE) techniques. In another sub-range, specific display values from a color table different from the first may be are assigned to specific intensity values. Lower temperatures may be assigned colors using HE and higher temperatures are assigned specific colors corresponding to specific temperatures. Such an arrangement is particularly applicable to thermal imaging use by firefighters because the arrangement allows them to determine temperature directly from displayed color for potentially dangerous temperatures.

Color display modes for a thermal imaging system

An imaging system includes an array of photodetectors and electronic circuitry associated with the photodetectors to read intensity values from the photodetectors. The electronic circuitry can include an integrator with an integrator capacitor having a nominal capacitance, wherein a gain of the electronic circuitry associated with a photodetector can depend at least in part on the actual capacitance of the integrator capacitor, the actual capacitance differing from the nominal capacitance. The imaging system can be configured to determine a gain factor that depends at least in part on the actual capacitance and/or a signal voltage input to the integrator. The imaging system can be configured to apply the gain factor based at least in part on the actual capacitance of the integrator capacitor calculated. The imaging system can be a thermal imaging system and may include an infrared camera core.

Gain calibration for an imaging system

A method and an imaging system for adaptive shutter control wherein an imaging system can be configured to actuate a calibration element at various times and develop an offset correction or Non-Uniformity Correction (NUC). The system control processing units may acquire information derived from calibration data, regular imaging data or external data, which may be correlated with how fast the NUC is changing over time. How often calibration element is actuated may be adaptively determined from the correlating information and the actuation times may be adaptively controlled to optimally actuate as needed. In some embodiments the calibration element may be a shutter and calibration activation may include closing the shutter and providing a flat field image for calibration purposes.

Time based offset correction for imaging systems and adaptive calibration control

An imaging system includes a shutter, an array of photodetectors, and electronic circuitry associated with the photodetectors to read intensity values from the photodetectors, the electronic circuitry including elements configured to provide an operating bias point of the photodetectors. The imaging system includes components, such as a controller, configured to adaptively adjust the operating bias for the photodetectors wherein the adjustment is based at least in part on intermittent measurement of a flat field image. During use, the imaging system can be configured to perform intermittent adjustments of the operating bias based on changes in photodetector values for intermittently acquired flat field images. Adjustment of the operating bias may provide compensation for drift over time of the photodetectors and/or electronics due to effects including but not limited to temperature changes.

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Santa Barbara, CA, United States of America

Jason Wolfe