Method and apparatus for measuring light intensity for imaging
Inventors
Beldon, Patrick John • Macey, Paul David
Assignees
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Publication Number
US-11864866-B2
Publication Date
2024-01-09
Expiration Date
Abstract
A method of measuring light intensity for imaging using a light detector array comprising a plurality of light detectors arranged to generate an output corresponding to an intensity of incident light. In a first measurement mode the light detector array generates a first plurality of output signals, each generated by one group of proximate light detectors, each group comprising a light detector pair, the first plurality of output signals each corresponding to a difference between the light intensity detected by the light detectors of the group, and generating a light intensity measurement for each group from each received output signal of the first plurality of output signals. In a second measurement mode the light detector array generates a second plurality of output signals, and a light intensity measurement is generated for each light detector from the second plurality of output signals.
Core Innovation
The document describes a near-infrared spectroscopy imaging system that measures light intensity using a light detector array including a plurality of light detectors. The system uses two measurement modes with different detector readout strategies. In the first measurement mode, groups of proximate light detectors form light detector pairs, and each output signal corresponds to a difference between the light intensity detected by the light detectors of the group.
In the second measurement mode, the system controls the light detector array to generate output signals for individual light detectors rather than grouped pairs. For the second measurement mode, a light intensity measurement is generated for each light detector from each received output signal of the second plurality of output signals. The document further describes forming imaging data by combining measurements from the relative and absolute modes.
The document describes hardware/control implementation for these modes using a photodiode detector array and bias voltage schemes. Voltage-bias and switching-matrix implementations are described to realize different reverse-bias states and measurement behavior, including bias/null/measurement voltages (Vbn, Vbp, Vbx, Vm). It also describes calibration using reference illumination to determine bias voltages for operation in the first and second measurement modes, including modulation between discrete programmable voltage levels.
Claims Coverage
The document contains two independent claims: clm-00001 (method) and clm-00021 (imaging apparatus). Each independent claim defines a two-mode imaging measurement approach using groups of proximate detectors forming detector pairs in a first mode and individual detectors in a second mode, with a light intensity measurement unit generating per-group or per-detector measurements.
Two measurement modes with proximate detector pairs and difference signals
A method/mode in which groups of proximate light detectors form a light detector pair, and an output signal corresponds to a difference between the light intensity detected by the light detectors of the group, followed by generating a light intensity measurement for each group from each received output signal.
Individual detector readout in a second measurement mode
A second measurement mode in which the light detector array is controlled to generate a second plurality of output signals, each output signal generated by one of the light detectors, and a light intensity measurement is generated for each light detector from each received output signal.
Imaging apparatus with first and second measurement-mode control
An imaging apparatus including a light detector array and means to control the plurality of light detectors, where in the first measurement mode it generates output signals for detector pairs based on a difference in detected light intensity and generates a light intensity measurement for each group, and in the second measurement mode it generates output signals for individual light detectors and generates a light intensity measurement for each light detector.
Overall, the claims cover an imaging approach that measures light intensity with two measurement modes: a first mode that derives outputs from differences between light intensities detected by proximate detector pairs, and a second mode that measures outputs from individual light detectors. The apparatus and method are aligned such that the system controls the detector array differently in each mode and produces per-group or per-detector light intensity measurements.
Stated Advantages
Improves resolution when pixel-to-pixel differences are small [as described in the relative measurement mode].
Documented Applications
Near-infrared spectroscopy imaging data generated from the light intensity measurements, including near-infrared spectroscopy imaging configured to image a subject’s head.
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