# US 10,310,670 B2 · System and method for capacitive sensing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,310,670 B2 - Document ID: US10310670B2 - Status: Granted - Kind: B2 - Application number: 15/543,924 - Filed: 2015-01-16 - Published: 2018-01-11 - Granted: 2019-06-04 - Earliest claimed: 2015-01-16 - Assignees: Silead Inc. - Applicants: Silead Inc. - Inventors: Taiyi Cheng - Web page: https://patentgrep.com/patent/US10310670B2 ## CPC - G06F 3/04166: {Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving (Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184)} - G06F 3/04186: {Touch location disambiguation} - G06F 3/0446: {using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes} - G06V 40/1306: {non-optical, e.g. ultrasonic or capacitive sensing} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING ## Abstract Disclosed is a system and method for a capacitive sensing device. The method includes transmitting a stimulation signal to a driving channel of the capacitive sensing device. The stimulation signal includes a plurality of sub-stimulation signals. Each of the sub-stimulation signals is characterized by an amplitude and a frequency. The frequencies of the sub-stimulation signals are orthogonal. The method further includes receiving a charge signal from a sensing channel of the capacitive sensing device. The charge signal is generated from the stimulation signal through a capacitance between the driving channel and the sensing channel. The method further includes detecting, from the charge signal, a plurality of sub-charge signal amplitudes at the frequencies of the sub-stimulation signals, and reporting a value about the capacitance from the sub-charge signal amplitudes. The method benefits the capacitive sensing device for increased noise immunity, reduced dynamic range, and reduced power consumption. ## Claims ### Claim 1 A method of driving and sensing for a capacitive sensing device, comprising: transmitting a stimulation signal to a driving channel of the capacitive sensing device, wherein the stimulation signal includes a plurality of sub-stimulation signals, each of the sub-stimulation signals is characterized by an amplitude and a frequency, and the frequencies of the sub-stimulation signals are orthogonal, wherein the transmitting of the stimulation signal includes combining the sub-stimulation signals into a first signal that has a lower frequency than the stimulation signal and converting the first signal to the stimulation signal; receiving a charge signal from a sensing channel of the capacitive sensing device, wherein the charge signal is generated from the stimulation signal through a capacitance between the driving channel and the sensing channel; detecting, from the charge signal, a plurality of sub-charge signal amplitudes at the frequencies of the sub-stimulation signals; and reporting a value about the capacitance from the sub-charge signal amplitudes. ### Claim 2 (depends on 1) The method of claim 1, wherein the reporting of the value about the capacitance includes: checking the sub-charge signal amplitudes for corruption; and upon a condition in which a corrupted sub-charge signal amplitude is found, giving it less weight than the ones of the sub-charge signal amplitudes that are not corrupted. ### Claim 3 (depends on 2) The method of claim 2, wherein the checking of the sub-charge signal amplitudes for corruption is based on correlation among the amplitudes of the sub-stimulation signals. ### Claim 4 (depends on 1) The method of claim 1, wherein the amplitudes of the sub-stimulation signals are the same. ### Claim 5 (depends on 1) The method of claim 1, wherein the amplitudes of the sub-stimulation signals form a subset of a random sequence. ### Claim 6 (depends on 1) The method of claim 1, wherein the amplitudes of the sub-stimulation signals form a subset of an error-correcting code. ### Claim 7 (depends on 6) The method of claim 6, wherein the error-correcting code is a Hadamard code. ### Claim 8 (depends on 1) The method of claim 1, wherein the amplitudes of the sub-stimulation signals form a subset of a Zadoff-Chu sequence. ### Claim 9 (depends on 1) The method of claim 1, wherein the detecting of the plurality of sub-charge signal amplitudes is performed at the same frequencies and phases as the sub-stimulation signals. ### Claim 10 (depends on 1) The method of claim 1, wherein the detecting of the plurality of sub-charge signal amplitudes is performed at the same frequencies as the sub-stimulation signals but with different phases. ### Claim 11 A method of driving and sensing for a capacitive sensing device, comprising: generating a plurality of stimulation signals, wherein each of the stimulation signals includes a plurality of sub-stimulation signals, each of the sub-stimulation signals is characterized by an amplitude and a frequency, and the frequencies of all the sub-stimulation signals are orthogonal, wherein the generating of the stimulation signals includes, for each of the stimulation signals, combining the respective sub-stimulation signals into a first signal that has a lower frequency than the stimulation signal and up-converting the first signal to the stimulation signal; transmitting the stimulation signals to a plurality of driving channels of the capacitive sensing device, wherein each one of the stimulation signals corresponds to each one of the driving channels; receiving a charge signal from a sensing channel of the capacitive sensing device, wherein the charge signal is generated from the stimulation signals through capacitances between the driving channels and the sensing channel; detecting, from the charge signal, a plurality of sub-charge signal amplitudes at the frequencies of the sub-stimulation signals; and reporting values about the capacitances from the sub-charge signal amplitudes. ### Claim 12 (depends on 11) The method of claim 11, wherein the stimulation signals each have the same number of sub-stimulation signals. ### Claim 13 (depends on 11) The method of claim 11, wherein at least two of the stimulation signals have different numbers of sub-stimulation signals. ### Claim 14 (depends on 11) The method of claim 11, wherein the amplitudes of the sub-stimulation signals are the same. ### Claim 15 (depends on 11) The method of claim 11, wherein the amplitudes of the sub-stimulation signals form a subset of: a random sequence, an error-correcting code, or a Zadoff-Chu sequence. ### Claim 16 (depends on 11) The method of claim 11, wherein the reporting of the values about the capacitances includes: checking the sub-charge signal amplitudes for corruption; and upon a condition in which a corrupted sub-charge signal amplitude is found, giving it less weight than the ones of the sub-charge signal amplitudes that are not corrupted. ### Claim 17 A system of driving and sensing for a capacitive sensing device, comprising: a driving module, adapted to transmit a stimulation signal to a driving channel of the capacitive sensing device, wherein the stimulation signal includes a plurality of sub-stimulation signals, each of the sub-stimulation signals is characterized by an amplitude and a frequency, the frequencies of the sub-stimulation signals are orthogonal, and the sub-stimulation signals are transmitted to the driving channel simultaneously; and a receiving module, adapted to perform: receiving a charge signal from a sensing channel of the capacitive sensing device wherein the charge signal is generated from the stimulation signal through a capacitance between the driving channel and the sensing channel; detecting, from the charge signal, a plurality of sub-charge signal amplitudes at the frequencies of the sub-stimulation signals; and reporting a value about the capacitance from the sub-charge signal amplitudes, wherein the driving module includes: a code generator, adapted to generate a plurality of codes; a modulator, adapted to modulate a plurality of orthogonal frequencies with the plurality of codes so as to generate the sub-stimulation signals; a mixer, adapted to combine the sub-stimulation signals into a first signal that has a lower frequency than the stimulation signal; and an up-converter, adapted to convert the first signal to the stimulation signal. ### Claim 18 (depends on 17) The system of claim 17, wherein the receiving module includes: a down-converter, adapted to convert the charge signal to a second signal that has a lower frequency than the charge signal; a de-modulator, adapted to detect the plurality of sub-charge signal amplitudes from the second signal; and a decision unit, adapted to calculate the value about the capacitance from the sub-charge signal amplitudes. ### Claim 19 (depends on 18) The system of claim 18, wherein: the de-modulator includes a plurality of match filter decoders at the orthogonal frequencies.