Patent ID: 8018587

Claim:
A method of monitoring fabric stretch and recovery, comprising: radiating energy having wavelength(s) in the range of from about 400 to about 2200 nanometers at a fabric that comprises a first plurality of reflective yarns knitted or woven with a second plurality of stretchable yarns, said fabric having a first side defining an exterior surface and a second side defining an opposite surface, said fabric having a region thereof defining gaps of a first size between yarns when said fabric is stretched and defining gaps of a second size between yarns that is different from said first size when the fabric recovers from stretch, detecting the amount of radiation reflected by or transmitted through a given irradiated area as the fabric is stretched with at least one detector responsive to incident radiation having wavelength(s) in the range of about 400 to about 2200 nanometers, to produce a signal representative thereof, and processing the signal with a signal processor that converts periodically varying signal output received from the detector or from a data acquisition unit associated with the detector into a signal representative of the stretch and recovery of the fabric, wherein a source emitting energy and the detector are associated with the fabric in fixed relative positions with respect to the region, such that the reception of incident radiation by the detector at a first time interval when the fabric is stretched as compared to the reception of incident radiation by the detector at a second time interval when the fabric recovers from stretch is directly affected by a change in the amount of light reflected by yarns or transmitted through the gaps as the fabric of the region periodically stretches and recovers from stretch.