公开(公告)号：US20190354743A1

公开(公告)日：2019-11-21

申请号：US15980446

申请日：2018-05-15

Applicant: QUALCOMM Incorporated

Inventor： Ashish HINGER ,  David William Burns ,  Bo-Ren WANG ,  Firas SAMMOURA ,  Sameer WADHWA ,  Lennart MATHE ,  Farhad TAGHIBAKHSH

IPC: G06K9/00

Abstract: An apparatus and method for efficiently increasing the signal-to-noise ratio of a biometric sampling system by implementing differential-sampling in successive differential-sampling operations and processing the output of the successive differential-sampling operations to create a biometric image. In some cases, the biometric image may be further noise-reduced by subtracting foreground-off and background-off data.

公开(公告)号：US20180052558A1

公开(公告)日：2018-02-22

申请号：US15271131

申请日：2016-09-20

Applicant: QUALCOMM Incorporated

Inventor： Bo-Ren WANG ,  Lennart MATHE ,  Sameer WADHWA ,  Nathan ALTMAN ,  Sandeep D'SOUZA

IPC: G06F3/041 ,  G06K9/00 ,  G06F3/044

CPC classification number: G06F3/0416 ,  G06F3/044 ,  G06K9/0002 ,  H03K17/955 ,  H03K17/962 ,  H03K2217/960725 ,  H03K2217/96074 ,  H03K2217/960745

Abstract: The present disclosure describes aspects of a capacitance-to-voltage modulation circuit. In some aspects, the circuit is used in touch sensing. In some aspects, a modulation circuit comprises a first pair of switches having one switch connected between a voltage source and a capacitor, and another switch connected between ground and the input of the circuit. The circuit also includes a second pair of switches having one switch connected between the voltage source and the input of the circuit, and another switch connected between ground and the capacitor. A third pair of the circuit's switches comprise one switch connected between the capacitor and an input of an analog-to-digital converter (ADC) and another switch connected between the input of the circuit and the input of the ADC. The third pair of switches may enable charge sharing of signals modulated by the first and second pairs of switches, a result of which can used to sense touch input based on capacitance at the input of the circuit.