Patent ID: 8937530
Filing Date: 2015-01-20
Classification: G06K

Abstract:
1. An apparatus, comprising: a wirelessly-powered radio frequency identification (RFID) tag with at least one light emitting diode (LED) that is powered by said RFID's power harvesting circuit in response to a tag specific illumination command; controllers to control the illumination state of said at least one LED and to automatically localize the RFID tag associated with a blinking LED by performing the action of filtering to accentuate intensity discontinuities and deemphasizes linear or flat regions, thresholding to ensure that only bright red light sources are considered, K-means clustering to ensure that only sufficiently large regions are considered, and selecting pixels whose on-off rate is within a given range; wherein said wirelessly-powered RFID tag powers said LED to provide bright duty-cycled illumination by discharging a storage capacitor when a sufficient operating voltage is reached.