Patent application number | Description | Published |
20090002206 | Noise resistant capacitive sensor - A switch capacitor unit for implementing a capacitive sensor includes a charging switch, a charge transfer switch, and a first switch. The charging switch is coupled between a first supply voltage and a circuit node to selectively couple a sensing capacitor to the first supply voltage through the circuit node. The charge transfer switch is coupled between the circuit node and a first terminal of a second capacitor to selectively couple the sensing capacitor through the circuit node to the second capacitor. The first switch is coupled between the circuit node and a second terminal of the second capacitor to selectively couple the second terminal to the sensing capacitor through the circuit node. | 01-01-2009 |
20090120697 | DISCERNING BETWEEN SUBSTANCES - A method and apparatus to detect the presence of a material at a sensing device and to determine whether the material is a first material having a first material property or a second material having a second material property. | 05-14-2009 |
20090153152 | COMPENSATION CIRCUIT FOR A TX-RX CAPACITIVE SENSOR - A capacitive sensor may include a transmit electrode and a receive electrode capacitively coupled with the transmit electrode. A capacitance sensing circuit senses a capacitance between the transmit and receive electrodes by applying a signal to the transmit electrode and rectifying a current waveform induced at the receive electrode. A compensation circuit reduces the effect of a mutual and parasitic capacitances of the transmit and receive electrode pair by adding a compensation current to the rectified current. | 06-18-2009 |
20120043973 | CAPACITANCE TO CODE CONVERTER WITH SIGMA-DELTA MODULATOR - An apparatus and method of converting a capacitance measured on a sensor element to a digital value. The apparatus may include a switching capacitor as a sensor element, a modulation circuit coupled to the sensor element, and a switching circuit having a plurality of switches controlled by a variable-period clock. The modulation circuit is configured to measure a capacitance on the sense element and to convert the measured capacitance to a digital value. | 02-23-2012 |
20120105361 | CAPACITIVE STYLUS WITH PALM REJECTION - A system comprising a sensing device and a capacitive sense array configured to detect a presence of a passive touch object and a stylus where the capacitive sense array receives a transmit signal from the stylus via capacitive coupling. The system further comprising a processing device configured to determine the stylus location on the capacitive sense array based on the transmit signal and to synchronize the stylus to the capacitive sense array. | 05-03-2012 |
20120105362 | SYNCHRONIZING A STYLUS WITH A CAPACITIVE SENSE ARRAY - A system and method for tracking a stylus on a capacitive sense array. The system comprising the capacitive sense array configured to detect a presence of the stylus, a processing device to generate a synchronization signal, and a transmitter to transmit the synchronization signal to the stylus to synchronize the stylus to the capacitive sense array. The system further comprises a magnetic antenna configured to inductively transmit the synchronization signal to the stylus, wherein the magnetic antenna is disposed around the outer edges of the capacitance sense array, according to an embodiment of the invention. | 05-03-2012 |
20120200307 | COMPENSATION CIRCUIT FOR A TX-RX CAPACITIVE SENSOR - A capacitive sensor may include a transmit electrode and a receive electrode capacitively coupled with the transmit electrode. A capacitance sensing circuit senses a capacitance between the transmit and receive electrodes by applying a signal to the transmit electrode and rectifying a signal induced at the receive electrode. A compensation circuit reduces the effect of a mutual and parasitic capacitances of the transmit and receive electrode pair by adding a compensation signal to the rectified signal. | 08-09-2012 |
20120268142 | CAPACITIVE PANEL SCANNING WITH REDUCED NUMBER OF SENSING CIRCUITS - Embodiments described herein provide capacitive sensor devices and methods for operating capacitive sensor devices. A first number of electrodes on the capacitive sensor array is activated. A signal is received from each of the first number of electrodes with a second number of receiver circuits on a controller associated with the capacitive sensor array. The first number is greater than the second number. It is determined if an object is proximate the capacitive sensor array based on the signals received from the first number of electrodes. | 10-25-2012 |
20120268415 | METHOD AND APPARATUS TO IMPROVE NOISE IMMUNITY OF A TOUCH SENSE ARRAY - A method for improving noise immunity of capacitive sensing circuit associated with a touch sense array is disclosed. The capacitive sensing circuit receives a response signal from a touch sense array. The capacitive sensing circuit measures a noise component of the response signal. When a level of noise of the noise component within a passband of the capacitive sensing circuit is greater than a threshold, the capacitive sensing circuit changes at least one parameter of capacitive sensing circuit to move the passband substantially outside the frequency spectrum of the noise component. | 10-25-2012 |
20120268416 | CAPACITIVE SENSING WITH PROGRAMMABLE LOGIC FOR TOUCH SENSE ARRAYS - A touch sense controller configured to be coupled to a touch sense array is disclosed. The touch sense controller includes programmable logic that includes programmable logic elements configured to manage measurement of capacitance associated with the touch sense array. | 10-25-2012 |
20130021291 | QUADRATURE SIGNAL RECEIVER USING SYNCHRONIZED OSCILLATOR - A system comprises a processing device, a signal generator to generate a first signal and a single receiver to receive a second signal from a capacitive sense array. The single receiver is configured to process the second signal for stylus sensing of a stylus proximate to the capacitive sense array in a first mode of operation and to process the second signal for touch sensing of a passive touch object proximate to the capacitive sense array in a second mode of operation. The second signal is unsynchronized with the first signal. | 01-24-2013 |
20130027346 | METHOD AND APPARATUS FOR PARALLEL SCANNING AND DATA PROCESSING FOR TOUCH SENSE ARRAYS - A parallel pipelining method of operation of a touch sense controller for processing data into a touch map is disclosed. A current full scan of response signals to at least one excitation of a touch sense array is received using a first thread of a processing device. The current full scan of response signals is processed using a second thread of the processing device to render a touch map corresponding to the touch sense array. A next full scan of response signals is received using the first thread. Receiving the next full scan and processing the current full scan are performed substantially simultaneously. | 01-31-2013 |
20130207926 | STYLUS TO HOST SYNCHRONIZATION - A system and method for synchronizing a stylus to a capacitive sense array. The system including a capacitive sense array which includes a plurality of electrodes. A synchronization signal is transmitted to the stylus using the plurality of electrodes. The synchronization signal is transmitted to the stylus by capacitively coupling the stylus to the capacitive sense array. | 08-15-2013 |
20130207938 | ACTIVE STYLUS TO HOST DATA TRANSMITTING METHOD - Apparatuses and methods of active stylus to host device data transmitting. One method receives, at a stylus, an indication that a host device is performing a first coordinate scan to determine coordinates of the stylus proximate to a capacitive sense array of the host device. While the host device is performing the first coordinate scan, the stylus transmits at least two bits of stylus data to the host device. | 08-15-2013 |
20130207939 | STYLUS TO HOST SYNCHRONIZATION USING A MAGNETIC FIELD - A system and method for synchronizing a stylus to a capacitive sense array. The system including a capacitive sense array which includes a plurality of electrodes. A magnetic field is generated using the plurality of electrodes. The magnetic field is used to synchronize the operation of the stylus and the capacitive sense array. | 08-15-2013 |
20130278447 | CAPACITANCE TO CODE CONVERTER WITH SIGMA-DELTA MODULATOR - An apparatus and method of converting a capacitance measured on a sensor element to a digital value. The apparatus may include a matrix-scanning device including drive lines and sense lines. A sense element is located at an intersection of one of the drive lines and one of the sense lines. The apparatus also includes a modulation circuit coupled to the drive lines and the sense lines, and a switching circuit having first switches controlled by a clock. The modulation circuit is configured to measure a mutual capacitance on the sense element and to convert the measured mutual capacitance to a first digital value. The modulation circuit is configured to measure a self-capacitance on at least one of the drive lines and to convert the measured self-capacitance to a second digital value. | 10-24-2013 |
20130314109 | MULTI-FUNCTIONAL CAPACITANCE SENSING CIRCUIT WITH A CURRENT CONVEYOR - An apparatus for and a method of sensing capacitance of one or more sensor elements in multiple capacitance sensing modes, including a self-capacitance sensing mode and a mutual capacitance sensing mode. | 11-28-2013 |
20140316729 | HARDWARE DE-CONVOLUTION BLOCK FOR MULTI-PHASE SCANNING - Apparatuses and methods of hardware de-convolution for multi-phase scanning of a touch arrays are described. One apparatus includes a memory device configured to store a capacitance map including convolved capacitance data. The convolved data are results of multi-phase transmit (TX) scanning of a sense array with multiple TX patterns. The apparatus further comprises a de-convolution circuit block coupled to the memory device. The de-convolution circuit block is configured to de-convolve the convolved capacitance data with inverses of the multiple TX patterns to obtain capacitance data for a de-convolved capacitance map. | 10-23-2014 |