Patent application number | Description | Published |
20120217978 | BACKGROUND NOISE MEASUREMENT AND FREQUENCY SELECTION IN TOUCH PANEL SENSOR SYSTEMS - A touch panel sensor system that can dynamically measure noise and automatically switch to a frequency with minimal noise is described. The touch panel sensor system includes a sensor configured to detect a change in capacitance associated with a touch upon a touch panel. The system also includes a drive module configured to generate a drive signal having a first waveform characteristic (e.g., signal having a periodic waveform characteristic) during a first phase (e.g., sensor phase) and a second drive signal having a second waveform characteristic (e.g., constant voltage signal) during a second phase (e.g., noise detection phase). The first and second drive signals are configured to drive the sensor. The system also includes a measuring module coupled to the sensor that is configured to measure noise having the first waveform characteristic (e.g., periodic waveform characteristic) during the second phase. | 08-30-2012 |
20120217981 | CIRCUITS, DEVICES AND METHODS HAVING PIPELINED CAPACITANCE SENSING - Capacitance sensing circuits, systems and method can include sample and hold (S/H) circuits that can retain analog values for one set of capacitance sensors, and sequentially convert such analog values into digital values while analog values for another set of capacitance sensors values are generated. | 08-30-2012 |
20120218020 | CALIBRATION FOR MIXED-SIGNAL INTEGRATOR ARCHITECTURE - A mixed signal correlator utilizes coherent detection within a capacitance measurement application. In some applications, the mixed signal correlator is used to measure capacitance of a touch screen display. An external capacitor whose capacitance is measured is kept small for improved sensitivity and can be used for a variety of applications having varied integration periods for measurement. The external capacitor is kept small and can be used for varied applications by adjusting the output voltage within a range that is less than the supply voltage, and maintaining a count of the adjustments to later reconstruct an actual output voltage for the integration period. An output is a weighted sum of an analog integrator output and a digital counter output. | 08-30-2012 |
20120218222 | CANCELLING TOUCH PANEL OFFSET OF A TOUCH PANEL SENSOR - A touch panel sensor system for increasing the dynamic range of the system is disclosed. The touch panel sensor system comprises a sensor driver module for driving one or more sensors of a touchscreen and an offset cancellation driver module for driving an offset cancellation module. The signals generated by the sensors and the offset cancellation module are coupled to a measuring module at a node (N | 08-30-2012 |
20120218223 | CONTINUOUS TIME CORRELATOR ARCHITECTURE - An analog front end circuit utilizes coherent detection within a capacitance measurement application. The analog front end circuit uses coherent detection to measure capacitance of a touch screen display. An analog excitation signal is modulated by a capacitor to be measured. The modulated signal is synchronously demodulated using a correlator, which includes an integrated mixing and integration circuit. The correlator includes a programmable impedance element that generates a time-varying conductance according to a controlling digitized waveform. | 08-30-2012 |
20120274404 | MIXED-SIGNAL INTEGRATOR ARCHITECTURE - A mixed signal correlator utilizes coherent detection within a capacitance measurement application. In some applications, the mixed signal correlator is used to measure capacitance of a touch screen display. An external capacitor whose capacitance is measured is kept small for improved sensitivity and can be used for a variety of applications having varied integration periods for measurement. The external capacitor is kept small and can be used for varied applications by adjusting the output voltage within a range that is less than the supply voltage, and maintaining a count of the adjustments to later reconstruct an actual output voltage for the integration period. An output is a weighted sum of an analog integrator output and a digital counter output. | 11-01-2012 |
20120293455 | TOUCH PANEL TESTING USING MUTUAL CAPACITOR MEASUREMENTS - A capacitive touch panel is tested for the presence or absence of short and open circuits in drive and sense lines without the use of a tool that touches the surface of the panel. During a first stage of testing, drive lines of the touch panel are sequentially driven while the remaining drive lines are floated. Sense lines are read to indicate whether a driven drive line is shorted to an adjacent drive line, an open circuit, or coupled to a sense line that is an open circuit. During a second stage of testing, drive lines are driven while alternate sense lines are floated or enabled. The signals on the enabled sense lines are acquired to indicate whether the enabled sense lines are shorted to adjacent sense lines. This second stage can be repeated, switching the roles of the sense lines, to determine the locations of short and/or open circuits. | 11-22-2012 |
20130162586 | CAPACITIVE TOUCH SENSE ARCHITECTURE - An analog front end circuit utilizes coherent detection within a capacitance measurement application. The analog front end circuit uses coherent detection to measure capacitance of a touch screen display. An analog excitation signal is modulated by a capacitor to be measured. The modulated signal is synchronously demodulated using a correlator, which includes a discrete mixer and a discrete integrator. The excitation signal is also input to the mixer such that the modulated signal is multiplied by the excitation signal. The excitation signal is an analog signal having a sine wave function or other waveform. | 06-27-2013 |
20130194225 | TOUCH PANEL EXCITATION USING A DRIVE SIGNAL HAVING TIME-VARYING CHARACTERISTICS - A capacitive touch panel may include a driver and a drive electrode configured to be connected to the driver. The driver is configured to power the drive electrode with a drive signal having a first signal characteristic during a first time interval, and a second signal characteristic different from the first signal characteristic during a second time interval subsequent to the first time interval. The first signal characteristic may comprise one or more of a first frequency, a first phase, or a first amplitude during the first time interval, and the second signal characteristic may comprise one or more of a second frequency, a second phase, or a second amplitude, where one or more of the first frequency, first phase, or first amplitude may be different from one or more of the second frequency, second phase, or second amplitude, respectively. | 08-01-2013 |
20130207923 | CAPACITIVE TOUCH PANEL HAVING PROTRUSIONS FORMED BETWEEN DRIVE AND/OR SENSOR ELECTRODES - A capacitive touch panel includes elongated drive electrodes arranged next to one another and having a characteristic spacing between adjacent drive electrodes. The capacitive touch panel also includes elongated sensor electrodes arranged next to one another across the drive electrodes and having a characteristic spacing between adjacent sensor electrodes. The drive electrodes and/or the sensor electrodes have protrusions into the spaces between adjacent electrodes. The characteristic spacing between the sensor electrodes may be at least substantially greater than the characteristic spacing between the drive electrodes. The sensor electrodes may have a pitch based upon a touch diameter of a finger, and the touch panel may be capable of sensing a stylus having a touch diameter substantially less than the touch diameter of the finger. | 08-15-2013 |
20130207924 | CAPACITIVE TOUCH PANEL FOR MITIGATING AND/OR EXAGGERATING FLOATING CONDITION EFFECTS - A capacitive touch panel includes elongated drive electrodes arranged next to one another and elongated sensor electrodes arranged next to one another across the drive electrodes. Together, the drive electrodes and the sensor electrodes define a coordinate system where each coordinate location comprises a capacitor formed at an intersection between one of the drive electrodes and one of the sensor electrodes. In implementations, the drive electrodes and/or the sensor electrodes are configured to block capacitance between a touch at a coordinate location and the drive electrodes during a floating condition for the panel. In other implementations, the drive electrodes and/or the sensor electrodes are configured to exaggerate capacitance between a touch at a coordinate location and the drive electrodes during a floating condition for the panel. | 08-15-2013 |
20140104221 | CAPACITIVE TOUCH PANEL SENSOR FOR MITIGATING EFFECTS OF A FLOATING CONDITION - A capacitive touch panel includes elongated drive electrodes arranged next to one another and elongated sense electrodes arranged next to one another across the elongated drive electrodes. One or more of the elongated drive electrodes defines a notch along an edge of a drive electrode, where the notch is positioned between adjacent sense electrodes. In some embodiments, the drive electrode also defines a generally opposing notch on an opposing edge of the drive electrode. Additionally, one or more of the elongated sense electrodes can define an elongated aperture, and a second notch can be defined along the edge of the drive electrode proximate to the elongated aperture. | 04-17-2014 |
20140152328 | CONTINUOUS TIME CORRELATOR ARCHITECTURE - A system includes a signal generator and a correlator. The signal generator outputs a first signal to a first end of a capacitance to be measured. The correlator is connected to an output of the signal generator that outputs the first signal and to a second end of the capacitance. The correlator receives the first signal from the output of the signal generator and receives a second signal from the second end of the capacitance. The correlator correlates the first signal and the second signal and generates an output signal based on a correlation between the first signal and the second signal. The output signal is proportional to a capacitance value of the capacitance. | 06-05-2014 |
20140375598 | SYSTEM AND METHOD TO DRIVE TOUCH PANEL TO MEASURE HOVER - Techniques in accordance with the present disclosure allow the detection of hover events and/or touch events performed over the touch panel without requiring that the touch panel be equipped with additional hardware and/or materials. In one or more implementations, the apparatus includes a touch panel controller configured to operatively couple to a touch panel sensor. The touch panel sensor includes at least one drive electrode and at least one sense electrode. The touch panel controller includes output circuitry operatively coupled to the at least one drive electrode. The output circuitry is configured to generate drive signals to drive the drive electrode (i.e., drive the touch panel sensor). The touch panel controller also includes input circuitry operatively coupled to the at least one sense electrode. The input circuitry is configured to measure mutual-capacitance between the at least drive electrode and the at least one sense electrode to detect a hover event. The present disclosure is directed to driving a subset of rows (or columns) and senses the subset of the remaining rows (or columns). Thus, the same sensor can measure multi-touch event and hover without changes to sensor pattern. | 12-25-2014 |
20150048851 | CAPACITIVE TOUCH SENSE ARCHITECTURE HAVING A CORRELATOR FOR DEMODULATING A MEASURED CAPACITANCE FROM AN EXCITATION SIGNAL - An analog front end circuit utilizes coherent detection within a capacitance measurement application. The analog front end circuit uses coherent detection to measure capacitance of a touch screen display. An analog excitation signal is modulated by a capacitor to be measured. The modulated signal is synchronously demodulated using a correlator, which includes a discrete mixer and a discrete integrator. The excitation signal is also input to the mixer such that the modulated signal is multiplied by the excitation signal. The excitation signal is an analog signal having a sine wave function or other waveform. | 02-19-2015 |