Patent ID: 9665223
Date: 2017-05-30
CPC Classifications: G06F

Claim:
1. A capacitive dongle intended to be used with a visualization device including a capacitive touch-sensitive surface comprising a matrix of conductive rows and columns, the capacitive dongle being arranged on the capacitive touch-sensitive surface in an operational use, the capacitive dongle operating in a send mode and in a receive mode, the capacitive dongle comprising: a voltage generator coupled to a digital-to-analog converter (DAC) that are used to send periodic analog signals, the periodic analog signals are sent with at least one specific frequency, wherein the specific frequency is a dongle frequency; a ring-shaped flat conductive metal part connected to the DAC that is coupled to the voltage generator, the ring-shaped flat conductive metal part is placed on the capacitive touch-sensitive surface, wherein variations in capacitance are detected on the conductive rows of the capacitive touch-sensitive surface that are caused by the placement of the capacitive dongle having a symmetrical profile that includes two peaks spaced apart by an inner diameter of the ring surrounding a central trough, wherein the symmetrical profile is identical over the conductive columns of the capacitive touch-sensitive surface; an analog transmission-reception sub-assembly coupled to an analog-to-digital converter (ADC) that is used to receive a received signals output of the ring-shaped flat conductive metal part; a synchronous demodulator circuit and an envelope detector that are coupled to a digital processor used to analyze digitized received signals from the received signals output; a storage device to store the sent periodic analog signals and the analyzed digitized received signals; and a digital communication interface.