| Patent application number | Description | Published |
|---|
| 20080309622 | Periodic sensor autocalibration and emulation by varying stimulus level - The automatic calibration of a sensor panel is disclosed by varying the amplitude of an input stimulus Vstim to simulate a full-touch condition and calibrating each pixel of the sensor panel in accordance with the difference between the simulated full-touch condition and a baseline full-touch condition. To accomplish this, a baseline full scale output FS_targ_cal can be measured at during pre-delivery calibration for each pixel using a test fixture capable of applying a no-touch to full-touch condition given a nominal Vstim. A full-touch condition can then be emulated for each pixel by lowering Vstim until the current full scale output FS_targ_current equals FS_targ_cal, and determining the Vstim value Vstim_cal at that point. During field calibration, Vstim_cal can be applied to each pixel to simulate a full-touch condition, and FS_targ_current can be obtained and compared against FS_targ_cal. Each analog channel can then be tuned so that in subsequent full-touch conditions, FS_targ_current will approximately equal FS_targ_cal. | 12-18-2008 |
| 20080309625 | Multiple simultaneous frequency detection - The use of multiple stimulation frequencies and phases to generate an image of touch on a touch sensor panel is disclosed. Each of a plurality of sense channels can be coupled to a column in a touch sensor panel and can have multiple mixers. Each mixer in the sense channel can utilize a circuit capable generating a demodulation frequency of a particular frequency. At each of multiple steps, various phases of selected frequencies can be used to simultaneously stimulate the rows of the touch sensor panel, and the multiple mixers in each sense channel can be configured to demodulate the signal received from the column connected to each sense channel using the selected frequencies. After all steps have been completed, the demodulated signals from the multiple mixers can be used in calculations to determine an image of touch for the touch sensor panel at each frequency. | 12-18-2008 |
| 20080309628 | Detection of low noise frequencies for multiple frequency sensor panel stimulation - The identification of low noise stimulation frequencies for detecting and localizing touch events on a touch sensor panel is disclosed. Each of a plurality of sense channels can be coupled to a separate sense line in a touch sensor panel and can have multiple mixers, each mixer using a demodulation frequency of a particular frequency, phase and delay. With no stimulation signal applied to any drive lines in the touch sensor panel, pairs of mixers can demodulate the sum of the output of all sense channels using the in-phase (I) and quadrature (Q) signals of a particular frequency. The demodulated outputs of each mixer pair can be used to calculate the magnitude of the noise at that particular frequency, wherein the lower the magnitude, the lower the noise at that frequency. Several low noise frequencies can be selected for use in a subsequent touch sensor panel scan function. | 12-18-2008 |
| 20090009483 | SINGLE-CHIP TOUCH CONTROLLER WITH INTEGRATED DRIVE SYSTEM - A touch controller for controlling a touch sensor panel is provided. The touch controller includes a plurality of sense channels that receive sensor signals from the touch sensor panel, a drive system that generates a plurality of stimulation signals based on a supply voltage on the order of digital logic level supply voltages, the stimulation signals for simultaneously stimulating multiple drive lines of the touch sensor panel, and a channel controller that controls the sense channels and the drive system. The plurality of sense channels, the drive system, and the channel controller are formed on a single chip. | 01-08-2009 |
| 20090189867 | Auto Scanning for Multiple Frequency Stimulation Multi-Touch Sensor Panels - The use of multiple stimulation frequencies and phases is disclosed to detect touch events on a touch sensor panel in a low-power state. Simultaneously during every frame, a number of rows of the touch sensor panel can be driven with a positive phase of one or more stimulation signals, and the same number of different rows can be driven with the anti-phase of those same stimulation signals. Because the same number of rows are stimulated with the in-phase and anti-phase components of the one or more stimulation signals, the resulting charges injected into a given column cancel each other out. However, a touch event will create an imbalance, and a non-zero charge will be detected. The detection of the touch event can then trigger the system to wake up, activate a panel processor, and perform a full panel scan, where the location of the touch event can be identified. | 07-30-2009 |
| 20090212642 | CHARGE RECYCLING FOR MULTI-TOUCH CONTROLLERS - The recycling of charge when two or more of the drive lines of a touch sensor panel are being simultaneously stimulated with the in-phase and anti-phase components of a stimulation signal is disclosed. To perform charge recycling, a discharge path can be selectively formed between drive lines being stimulated with the in-phase and anti-phase components of the stimulation signal. A multiplexer can be coupled to the driver of each drive line and the common discharge path. When charge recycling is to be performed, control logic can configure the multiplexers to isolate the driver and connect the drive lines being stimulated with the in-phase component of the stimulation signal with the drive lines being stimulated with the anti-phase component of the stimulation signal. The capacitance on the charged-up drive lines can then discharge to the capacitance on the discharged drive lines. | 08-27-2009 |
| 20090244014 | SAR ADC WITH DYNAMIC INPUT SCALING AND OFFSET ADJUSTMENT - An apparatus for generating an image of touch on or about a touch-sensitive surface comprising a touch panel is disclosed. The touch panel can include a plurality of touch sensors configured for detecting one or more touch events occurring at distinct locations at about the same time. Each touch event can comprise a touching of an object against the touch-sensitive surface. A plurality of receive channels can be coupled to the touch panel for generating values representative of detected touch events. The receive channels can include a charge redistribution successive approximation register digital-to-analog converter (SAR ADC) configured to convert an analog waveform into a digital representation via a binary search and outputting the digital representation to an output register. The SAR ADC architecture can be such that it the dynamic input range can be scaled and offset adjusted. | 10-01-2009 |
| 20090315850 | Multipoint Touch Surface Controller - A multipoint touch surface controller is disclosed herein. The controller includes an integrated circuit including output circuitry for driving a capacitive multi-touch sensor and input circuitry for reading the sensor. Also disclosed herein are various noise rejection and dynamic range enhancement techniques that permit the controller to be used with various sensors in various conditions without reconfiguring hardware. | 12-24-2009 |
| 20100059295 | Single-chip multi-stimulus sensor controller - A multi-stimulus controller for a multi-touch sensor is formed on a single integrated circuit (single-chip). The multi-stimulus controller includes a transmit oscillator, a transmit signal section that generates a plurality of drive signals based on a frequency of the transmit oscillator, a plurality of transmit channels that transmit the drive signals simultaneously to drive the multi-touch sensor, a receive channel that receives a sense signal resulting from the driving of the multi-touch sensor, a receive oscillator, and a demodulation section that demodulates the received sense signal based on a frequency of the receive oscillator to obtain sensing results, the demodulation section including a demodulator and a vector operator. | 03-11-2010 |
| 20100060590 | Channel Scan Architecture for Multiple Stimulus Multi-Touch Sensor Panels - A channel scan architecture for detecting touch events on a touch sensor panel is disclosed. The channel scan architecture can combine drive logic, sense channels and channel scan logic on a single monolithic chip. The channel scan logic can be configured to implement a sequence of scanning processes in a panel subsystem without intervention from a panel processor. The channel scan architecture can provide scan sequence control to enable the panel processor to control the sequence in which individual scans are implemented in the panel subsystem. Type of scans that can be implemented in the panel subsystem can include a spectral analysis scan, touch scan, phantom touch scan, ambient light level scan, proximity scan and temperature scan. | 03-11-2010 |
| 20100064160 | Circuit Having a Low Power Mode - Embodiments of the invention include an IC that includes a core used for ordinary operation and a thin power circuit. The thin power circuit can be configured to use very little power. The IC can also include a digital interface and a connection thereto. The IC can initiate transition to low power mode during which the core and various I/O pads can be shut down. However, the thin power circuit can be kept powered up. The thin power circuit can monitor the digital interface for a predefined wake up signal. When the wake up signal is detected, the thin power circuit can power up the core and any powered down I/O pads. The thin power circuit can also include a dedicated power on reset (POR) cell. This POR cell can be distinct than other POR cells used for the IC and can be specifically designed to for efficient operation. | 03-11-2010 |
| 20100164898 | Channel Scan Logic - A device that can autonomously scan a sensor panel is disclosed. Autonomous scanning can be performed by implementing channel scan logic. In one embodiment, channel scan logic carries out many of the functions that a processor would normally undertake, including generating timing sequences and obtaining result data; comparing scan result data against a threshold value (e.g., in an auto-scan mode); generating row count; selecting one or more scanning frequency bands; power management control; and performing an auto-scan routine in a low power mode. | 07-01-2010 |
| 20100173680 | CHANNEL SCAN LOGIC - A device that can autonomously scan a sensor panel is disclosed. Autonomous scanning can be performed by implementing channel scan logic. In one embodiment, channel scan logic carries out many of the functions that a processor would normally undertake, including generating timing sequences and obtaining result data; comparing scan result data against a threshold value (e.g., in an auto-scan mode); generating row count; selecting one or more scanning frequency bands; power management control; and performing an auto-scan routine in a low power mode. | 07-08-2010 |
| 20100188356 | CHANNEL SCAN LOGIC - A device that can autonomously scan a sensor panel is disclosed. Autonomous scanning can be performed by implementing channel scan logic. In one embodiment, channel scan logic carries out many of the functions that a processor would normally undertake, including generating timing sequences and obtaining result data; comparing scan result data against a threshold value (e.g., in an auto-scan mode); generating row count; selecting one or more scanning frequency bands; power management control; and performing an auto-scan routine in a low power mode. | 07-29-2010 |
| 20110025634 | DETECTION OF LOW NOISE FREQUENCIES FOR MULTIPLE FREQUENCY SENSOR PANEL STIMULATION - The identification of low noise stimulation frequencies for detecting and localizing touch events on a touch sensor panel is disclosed. Each of a plurality of sense channels can be coupled to a separate sense line in a touch sensor panel and can have multiple mixers, each mixer using a demodulation frequency of a particular frequency, phase and delay. With no stimulation signal applied to any drive lines in the touch sensor panel, pairs of mixers can demodulate the sum of the output of all sense channels using the in-phase (I) and quadrature (Q) signals of a particular frequency. The demodulated outputs of each mixer pair can be used to calculate the magnitude of the noise at that particular frequency, wherein the lower the magnitude, the lower the noise at that frequency. Several low noise frequencies can be selected for use in a subsequent touch sensor panel scan function. | 02-03-2011 |
| 20110061947 | Power Management for Touch Controller - Power management for a touch controller is disclosed. The touch controller can include a transmit section for transmitting stimulation signals to an associated touch sensor panel to drive the panel, where the touch controller can selectively adjust the transmit section to reduce power during the transmission. The touch controller can also include a receive section for receiving touch signals resulting from the driving of the panel, where the touch controller can selectively adjust the receive section to reduce power during the receipt of the touch signals. The touch controller can also include a demodulation section for demodulating the received touch signals to obtain touch event results, where the touch controller can selectively adjust the demodulation section to reduce power during the demodulation of the touch signals. The touch controller can also selectively reduce power below present low levels during idle periods. The touch controller can be incorporated into a touch sensitive device. | 03-17-2011 |
| 20110061948 | Touch Controller with Improved Diagnostics Calibration and Communications Support - A touch controller with improved diagnostics calibration and communication support includes a data capture register configured to sample data from one or a plurality of touch panel sense channels at an output of an analog to digital (A/D) converter. The sampled data is bit packed, and a demodulation waveform is captured, correlated with the sampled data. The contents of the data capture register, including the sampled data and the demodulation waveform, are transferred to a memory configured to create one or more records from the transferred contents. A processor can be used to extract the one or more records captured in the memory to display to a user for diagnostics or calibration. | 03-17-2011 |
| 20110061949 | MEASURING BODY CAPACITANCE EFFECT IN TOUCH SENSITIVE DEVICE - Measuring an effect of body capacitance in a touch sensitive device is disclosed. This effect can be caused by poor grounding of a user or other objects touching the device or of the device itself. The device can operate in a stray capacitance mode to measure a body capacitance effect and in a normal mode to detect a touch on the device. During the stray capacitance mode, the device can obtain a body capacitance measurement from the device. During the normal mode, the device can obtain a touch measurement from the device. The device can calculate a body capacitance factor based on a ratio between the body capacitance measurement and the touch measurement and use the body capacitance factor to compensate for erroneous or distorted touch output values from the device. Various components of the device can be switchably configured according to the particular mode. | 03-17-2011 |
| 20110063154 | TOUCH CONTROLLER WITH IMPROVED ANALOG FRONT END - A controller for a touch sensor includes a transimpedance amplifier, and a feedback resistor coupled to an input of the transimpedance amplifier and to an output of the transimpedance amplifier. At least one multiplexor may be coupled to the input of the transimpedance amplifier and configured to multiplex a plurality of analog inputs to one dedicated channel. The controller may further include a bandpass filter coupled to the output of the transimpedance amplifier. The output of the bandpass filter may be input to an anti-aliasing filter, which feeds into an analog to digital converter. Alternatively, the output of the bandpass filter may be input to a sigma-delta analog to digital converter. | 03-17-2011 |
| 20110063229 | METHOD TO COMPENSATE FOR THE FREQUENCY DEPENDENCE OF SENSE SIGNAL PREPROCESSING - Compensating for the frequency dependence of sense signal preprocessing in preprocessing channel circuitry is provided. The frequency dependence of the preprocessing channels can be modified to change a frequency dependent channel into a frequency independent channel, to change a frequency independent channel into a frequency dependent channel, or to change the frequency dependency characteristics of a frequency dependent channel. Modification of frequency dependency may be accomplished, for example, by modifying certain parameters of a preprocessing channel's components, which can include components for amplifying, filtering, phase adjusting, demodulating, decrypting, for example. A pipelined process may be used to modify the frequency dependency of multiple channels. Compensating for frequency dependencies can have multiple advantages, such as reduction of memory requirements and DIE size. | 03-17-2011 |
| 20110063993 | Automatic Low Noise Frequency Selection - Automatic low noise frequency selection for a touch sensitive device is disclosed. A low noise stimulation frequency can be automatically selected by device logic without intervention of the device processor to stimulate the device to sense a touch event at the device. The device logic can automatically select a set of low noise frequencies from among various frequencies based on the amount of noise introduced by the device at the various frequencies, where the frequencies with the lower noise amounts can be selected. The device logic can also automatically select a low noise frequency from among the selected set as the low noise stimulation frequency. The device logic can be implemented partially or entirely in hardware. | 03-17-2011 |
