Phase calibration for capacitive touch sensing devices

Abstract

Phase calibration for a capacitive touch sensing device is provided. In an embodiment of the technology presented herein, a touch detection system includes: a touch sensor array having a transmit line, a receive line, and a unit cell defined at an intersection of the transmit line and the receive line; a transmit sequencer configured to generate a transmit signal on a transmit line; an analog-to-digital converter module configured to measure a response of the unit cell to the transmission signal; and a calibration unit configured to determine a first phase offset for a first one of the unit cells based on a first one of the responses of the first unit cell, determine a second phase offset for a second one of the unit cells based on a second one of the responses of the second unit cell, and setting a phase offset parameter of the touch sensor array based on the first phase offset and the second phase offset.

Description

Technical Field

[0001] This invention relates to phase calibration for capacitive touch sensing devices. Background Technology

[0002] Computing devices such as laptops, personal digital assistants (PDAs), and mobile handheld devices have user interface devices, such as touch sensor pads (often called touchpads), touch sensor sliders, touch sensor buttons, touch sensor keyboards, touchscreens, and touch panels. Capacitive sensing devices are sometimes used to replace mechanical buttons, knobs, and other similar mechanical user interface controls in user interface devices. Capacitive sensing devices have relatively fewer complex mechanical switches and buttons and can generally provide reliable operation under harsh conditions. In addition, capacitive sensing devices are widely used in modern customer applications, making it relatively easy to develop new user interface options in existing products. Summary of the Invention

[0003] The present invention is provided in a simplified form to introduce some concepts that are further described below in the detailed description. This summary is not intended to identify key elements or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0004] To achieve the foregoing and related objectives, the following description and accompanying drawings illustrate certain illustrative aspects and implementations. These merely indicate a few of the various methods in which one or more aspects may be adopted. Other aspects, advantages, and novel features of this disclosure will become apparent from the following detailed description when considered in conjunction with the accompanying drawings.

[0005] In one embodiment of the technology proposed herein, a method for touch detection includes: determining a first phase offset for a first unit cell of a touch sensor array, determining a second phase offset for a second unit cell of the touch sensor array, and setting a phase offset parameter of the touch sensor array based on the first phase offset and the second phase offset.

[0006] In one embodiment of the technology proposed herein, a touch detection system includes: a touch sensor array including a transmit line, a receive line, and unit cells defined at the intersection of the transmit line and the receive line; a transmit sequencer configured to generate transmit signals on the transmit lines; an analog-to-digital converter module configured to measure the response of the unit cells to the transmit signals; and a calibration unit configured to determine a first phase offset for a first unit cell based on a first response in the response of a first unit cell in the unit cells, determine a second phase offset for a second unit cell based on a second response in the response of a second unit cell in the unit cells, and set phase offset parameters of the touch sensor array based on the first phase offset and the second phase offset.

[0007] In an embodiment of the technology proposed herein, an apparatus includes: a display including a touch sensor array having a transmit line, a receive line, and unit cells defined at the intersections of the transmit and receive lines; a transmit sequencer configured to generate transmit signals for the transmit lines of the touch sensor array; an analog-to-digital converter module configured to measure the response of the receive lines to the transmit signals; and a calibration unit configured to determine a first phase offset for a first unit cell based on a first response in the response of a first unit cell in the unit cells, determine a second phase offset for a second unit cell based on a second response in the response of a second unit cell in the unit cells, and set a phase offset parameter for at least one of the transmit lines or the receive lines based on the first and second phase offsets.

[0008] In an embodiment of the technology proposed herein, a system for touch detection includes: means for determining a first phase offset for a first unit cell of a touch sensor array; means for determining a second phase offset for a second unit cell of the touch sensor array; and means for setting a phase offset parameter of the touch sensor array based on the first phase offset and the second phase offset. Attached Figure Description

[0009] Figure 1 This is a block diagram of a touch sensing system according to some implementation methods.

[0010] Figure 2 and Figure 3 This is a diagram of a phase calibration method for a touch sensing system according to some implementations.

[0011] Figure 4 This is a diagram illustrating a touch panel model according to some implementations.

[0012] Figure 5This is a diagram illustrating phase calibration according to some implementation methods.

[0013] Figure 6 This is a schematic diagram of a processing unit according to some implementation methods.

[0014] Figure 7 Exemplary embodiments of a computer-readable medium according to some implementations are shown. Detailed Implementation

[0015] The claimed subject matter will now be described with reference to the accompanying drawings, in which the same reference numerals are used throughout to refer to the same elements. In the following description, numerous specific details are set forth for illustrative purposes to provide a thorough understanding of the claimed subject matter. However, it will be apparent that the claimed subject matter can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form to facilitate the description of the claimed subject matter.

[0016] It should be understood that the following description of the embodiments should not be considered limiting. The scope of this disclosure is not intended to be limited to the embodiments or drawings described below, which are to be regarded as illustrative only. The drawings should be regarded as schematic diagrams, and the elements shown in the drawings are not necessarily shown to scale. Rather, the various elements are shown such that their function and general purpose will become apparent to those skilled in the art.

[0017] All numerical values ​​in the specific embodiments and claims herein are indicated values ​​modified by “about” or “approximately”, and take into account experimental errors and variations that would be expected by one of ordinary skill in the art.

[0018] Figure 1 This is a block diagram of a touch sensing system 100 according to some embodiments. In some embodiments, the touch sensing system 100 includes: a touch panel 101 (typically optically integrated to a display), the touch panel 101 including a touch sensor array 102, the touch sensor array 102 including a transmit (TX) line 104T and a receive (RX) line 104R; a multiplexer 106; a transmit sequencer 108; an analog-to-digital converter (ADC) module 110; a calibration unit 112; a signal processing unit (SPU) 114; and a post-processing unit 116. In some embodiments, one or more of the calibration unit 112, SPU 114, or post-processing unit 116 may be implemented using shared processing resources.

[0019] In some embodiments, the touch sensing system 100 uses capacitive sensing to determine the touch location on a human-machine interface (HMI) that provides user input to a device such as a smartphone, tablet, laptop, controller, or other user interface. The HMI may employ a touch-sensitive display that acts as both an output and input device. TX lines 104T and RX lines 104R define a grid of orthogonal electrodes. The intersection of TX lines 104T and RX lines 104R defines a unit cell of the touch sensor array 102. In some embodiments, TX lines 104T are vertical and RX lines 104R are horizontal. Alternatively, in some embodiments, TX lines 104T may be horizontal and RX lines 104R may be vertical.

[0020] Send signal (V) TX (For example, an excitation signal) is injected onto one or more selected TX lines 104T, and the response to the transmitted signal is measured on the RX line 104R. For example, the response of the RX line 104R can be measured in parallel using multiple sensing channels 104C in the ADC module 110 in response to the excitation of a single TX line 104T. In some embodiments, the transmitted signal (V... TX The signal is a conversion rate-limited signal, such as a sine wave, trapezoidal wave, or some other signal type. TX injection and RX measurement are repeated for each TX line 104T in the TX lines 104T until the scan cycle is complete. Transmit sequencer 108 controls the transmit signals on the TX lines 104T selected by multiplexer 106. In some embodiments, multiplexer 106 routes each RX line 104R in the RX lines 104R to a separate sensing channel 104C, allowing the response to be measured in parallel. In some embodiments, each sensing channel 104C includes an ADC 120 in ADC module 110 and a demodulator 122 and filter 124 in SPU 114. Demodulator 122 multiplies the output of ADC 120 by a demodulator reference signal (V). REF1…N The ADC 120 demodulates the RX response, and filter 124 filters the demodulated output, for example, through noise filtering, baseline filtering, hardware dejitter filtering, or some other filtering. In some embodiments, the ADC 120 is implemented as a Σ-Δ (sigma-delta) modulator, and filter 124 is a sinc filter or a chain of sinc filters with different decimation ratios. In some embodiments, the same demodulator reference signal (V...) REF (V) is used for each sensing channel 104C. In another embodiment, each sensing channel 104C may employ a different demodulator reference signal (V). REF1…N ).

[0021] SPU 114 processes data generated by ADC 120 for each of the TX lines 104T to generate response data for touch sensor array 102. In some embodiments, SPU 114 processes data from ADC 120 for noise reduction, gain equalization, etc. Post-processing unit 116 processes the response data to identify touch events, calculate one or more touch locations (e.g., single touch or multiple touches), determine touch attributes (e.g., direction of movement), or recognize gestures (e.g., over multiple scan cycles).

[0022] The performance of sensor array 102 is affected by the inherent signal propagation delay in the TX line 104T and RX line 104R. Lines 104T and 104R each have distributed line resistance and distributed line capacitance that increase with length based on a specific unit cell location, as well as parasitic capacitances appearing between adjacent lines 104T and 104R. The transmitted signal (V...) TX ) and receiver input current (I RX The phase delay between the RX and TX lines depends on the intersection location of the RX and TX lines (e.g., the unit cell location). Each TX line 104T and RX line 104R can be represented as a lumped delay line, where the net delay from the intersecting lumped delay line depends on the location of the unit cell. For example, with the received current (I... RX From the transmitted voltage (V) TX Compared to the ideal case with a 90° offset, the unit cell at position 2 exhibits the minimum delay. Compared to the ideal case, the unit cell at position 1 exhibits the highest delay, while the unit cells at positions 3 and 4 exhibit intermediate delays.

[0023] In some embodiments, calibration unit 112 determines one or more phase offset parameters based on the measured delay to account for touch signal inhomogeneities on the surface of touch sensor array 102. Sensing channel 104C is sensitive to the phase of the input current. Touch sensor array 102 comprises a conductive transparent material with limited conductivity, and the phase and amplitude of the input current vary per unit cell due to panel parasitic capacitance. Calibration unit 112 configures at least one phase offset parameter to account for phase variations on touch sensor array 102. In some embodiments, calibration unit 112 receives temperature data from temperature sensor 126 to trigger a calibration event. In some embodiments, calibration may be performed periodically to compensate for potential aging effects.

[0024] Figure 2 and Figure 3This is a diagram of phase calibration methods 200 and 300 for a touch sensing system 100 according to some embodiments. At 204, calibration unit 112 selects a first unit cell by configuring multiplexer 106 to select the first TX line 104T and the first RX line 104R. At 206, calibration unit 112 performs source phase calibration for the first unit cell to generate a first phase offset. Figure 3 Method 300 describes an example technique for performing source phase calibration. At 208, calibration unit 112 selects a second unit cell by configuring multiplexer 106 to select the second TX line 104T and the second RX line 104R. At 210, calibration unit 112 performs source phase calibration for the second unit cell to generate a second phase offset. At 212, calibration unit 112 configures the phase offset parameters of touch sensing system 100 based on the first phase offset and the second phase offset.

[0025] Reference Figure 3 Method 300 illustrates, for example, in Figure 2 The determination of the phase offset for the selected unit cell is performed at 206 or 210 of method 200. At 304, the unit cell is selected for calibration by configuring the transmit sequencer 108 and the multiplexer 106. In some embodiments, the multiplexer 106 may be configured to select a single TX line 104T and a single RX line 104R. In another embodiment, the multiplexer 106 may be configured to select a single TX line 104T and measure the responses of all RX lines 104R intersecting the selected TX line 104T in parallel. In yet another embodiment, the multiplexer 106 may be configured to select a subset of TX lines 104T and apply a transmit signal to that subset. The multiplexer 106 may be configured to select one RX line 104R for each TX line 104T in the subset, such that the transmit signal from a given TX line 104T appears only on one of the RX lines 104R.

[0026] At point 306, the touch sensing system 100 is initialized. For example, the signal transmission (V) can be set. TX ) and demodulator reference signal (V REF1 . N The parameters of the phase offset parameter are set at 308, and the initial value of the phase offset parameter is loaded at 310. In some implementations, the phase offset parameter is the phase offset applied to the TX signal. Alternatively, the phase offset can be applied to the reference signal (V) of the selected unit cell. REF1 . NAt 312, a scan of the touch sensor array 102 is performed. At 314, the response of the selected unit cell is determined for a given phase offset. In an embodiment where the ADC module 110 measures the responses of multiple RX lines 104R in parallel for a given transmitted signal, the responses of RX lines 104R not associated with the selected unit cell can be ignored. At 316, the calibration unit 112 determines whether the maximum phase offset has been reached. If the maximum phase offset has not been reached, the calibration unit 112 increments the phase offset at 318 and loads the offset register at 310. The scan at 312 and the response determination at 314 are repeated until the maximum phase offset is reached at 316. The calibration unit 112 determines the peak response at 320 and determines the phase offset associated with the peak response at 322. In other words, at 320, the phase offset that caused the peak system response is determined. Return to Figure 2 At 206, a first phase offset is generated using a phase offset associated with the peak response of the first unit cell, and at 210, a second phase offset is generated using a phase offset associated with the peak response of the second unit cell.

[0027] In some implementations, the calibration unit 112 uses a touch panel model 128 to perform the calibration. Figure 2 Phase calibration at 206 or 210. Touch panel model 128 can be used in... Figure 3 The response of a unit cell to a given phase offset is determined at position 314. In some implementations, reference is made to... Figure 4 The touch panel model 128 defines the lumped resistance and capacitance parameters of a specific unit cell, represented by the line resistance 400, line capacitance 402, and parasitic capacitance 404 of the unit cell. The TX output 406, specifying the TX signal attributes, is provided to the lumped parameters of the unit cell, and the RX input 408 is generated as the output of the touch panel model 128. The touch panel model 128 can be trained during manufacturing using actual measurements of the touch panel 101 or through simulation. The touch panel model 128 can generate responses for any unit cell specified by the row and column numbers or only for predetermined unit cells (i.e., the touch panel model 128 can be programmable). Figure 3 In the context of this, at 314, touch panel model 128 generates a panel response. In some embodiments, touch panel model 128 is used in applications where the characteristics of touch panel 101 are well characterized and exhibit low-level variation between panels, or in high-noise environments where readings are significantly affected by noise. Calibration unit 112 can use temperature data from temperature sensor 126 as input to touch panel model 128. For example, in some touch panel touch technologies, lumped resistance and capacitance parameters can be temperature-dependent (e.g., due to variations in the dielectric constant of the panel insulation layer).

[0028] In some implementations, calibration unit 112 can selectively use measured data or touch panel model 128 to calibrate the phase offset. Calibration unit 112 can compare the result of calibration using measured data with the result of calibration using touch panel model 128 to identify noisy environments. For example, if the results differ by a predetermined threshold amount, calibration unit 112 can use the result from touch panel model 128.

[0029] Figure 5 Figure 500 shows an example phase diagram 502 before calibration and a phase diagram 504 after calibration. In the phasor diagram, the transmitted signal (V... TX ) and demodulator reference signal (V REF1 . N The initial phase offset between them is 90°. The measured response I of the selected unit cell. RX1 I RX2 Relative to the demodulator reference signal (V) REF1 . N The transmitted signal (V) exhibits a first phase shift and a second phase shift. In phasor diagram 504, the transmitted signal (V) is modified based on the first and second phase shifts. TX ) relative to the demodulator reference signal (V REF1 . N The phase angle of the selected unit cell causes the response signal I. RX1 I RX2 The phase shift relative to the demodulator reference signal (V) REF1 . N The phase offset is reduced. The phase offset parameters of the touch sensing system 100 are calibrated based on the first and second phase offsets, thereby improving the performance of the touch sensing system by achieving a more uniform system response for different touch positions and providing better immunity to noise (e.g., from fingers or touch display 101) due to the final higher touch response.

[0030] In some implementations, the phase offset parameter modified by the calibration unit 112 based on the first phase offset and the second phase offset is related to the transmitted signal (V). TX The phase offset associated with the demodulator reference signal (V). Alternatively, the phase offset parameter modified by the calibration unit 112 based on the first and second phase offsets is related to the phase offset of the demodulator reference signal (V). REF1 . N The associated phase shift.

[0031] In some implementations, the phase offset parameter is globally associated with the touch sensing system 100. For example, in an implementation where the SPU 114 uses a common reference source for each sensing channel 104C, a first phase offset can be determined for a unit cell at position 1, a second phase offset can be determined for a unit cell at position 2, and the first and second phase offsets can be averaged to determine the signal to be applied to the transmitted signal (V). TX ) or common demodulator reference signal (V REF The phase offset parameter of ).

[0032] In the SPU 114, a different reference (V) is used for each sensing channel 104C. REF1 . N In the implementation of this method, it can be performed for each RX line 104R. Figure 2 and Figure 3 The calibration methods 200 and 300 involve selecting a first unit cell at one end of the selected RX line 104R and a second unit cell at the other end of the selected RX line 104R (e.g., positions 1 and 3 of the uppermost RX line 104R or positions 4 and 2 of the lowermost RX line 104R). The first and second phase offsets for each RX line 104R can be averaged to determine the demodulator reference signal (V0) to be applied to the selected RX line 104R. REF1…N The phase offset parameter of ).

[0033] In an implementation where SPU 114 uses a common reference for each sensing channel 104C, phase compensation can be provided for each TX line 104T by determining different phase offset parameters for each TX line 104T, generated based on a first phase offset at one end of the selected TX line 104T and a second phase offset at the other end of the selected TX line 104T. In this implementation, method 300 only needs to be performed once because the peak response and associated phase offset of the end unit cell of the selected TX line 104T can be determined based on the same set of iterative scan data. In some implementations, the calibration process is performed periodically or in response to various triggering events such as large touch panel temperature changes or other events affecting the parasitic capacitance and resistance of lines 104T and 104R. For example, calibration unit 112 may trigger calibration based on input from temperature sensor 126.

[0034] Figure 6This is a diagram of a processing unit 600 according to some embodiments. The processing unit 600 may implement one or more of a calibration unit 112, an SPU 114, or a post-processing unit 116. In some embodiments, the processing unit 600 includes a bus 602, a processor 604, a memory 606 storing software instructions or operations, an input device 608, an output device 610, a communication interface 612, and a power supply 614, such as a battery. The processing unit 600 may include... Figure 6 The components shown are fewer than those shown, with additional components, different components, and / or different arrangements of components.

[0035] According to some implementations, bus 602 includes paths enabling communication between components of processing unit 600. For example, bus 602 may include a system bus, address bus, data bus, and / or control bus. Bus 602 may also include bus drivers, bus arbitrators, bus interfaces, clocks, etc. Processor 604 includes one or more processors, microprocessors, data processors, coprocessors, application-specific integrated circuits (ASICs), controllers, programmable logic devices, chipsets, field-programmable gate arrays (FPGAs), application-specific instruction set processors (ASIPs), system-on-a-chip (SoCs), central processing units (CPUs) (e.g., one or more cores), microcontrollers, and / or other types of components that interpret and / or execute instructions and / or data. Processor 604 may be implemented as hardware (e.g., microprocessors, etc.), a combination of hardware and software (e.g., SoCs, ASICs, etc.), and may include one or more memories (e.g., caches, etc.).

[0036] Processor 604 performs one or more operations based on an operating system and / or various applications or computer programs (e.g., software). Processor 604 accesses instructions from memory 606, from other components of processing unit 600, and / or from sources outside processing unit 600 (e.g., a network, another device, etc.). Processor 604 may perform operations and / or processing based on various techniques including, for example, multithreading, parallel processing, pipelining, interleaved access, etc.

[0037] In some embodiments, memory 606 includes one or more memories and / or one or more other types of storage media. For example, memory 606 may include one or more types of memory, such as random access memory (RAM), dynamic random access memory (DRAM), cache, read-only memory (ROM), programmable read-only memory (PROM), static random access memory (SRAM), single in-line memory module (SIMM), dual in-line memory module (DIMM), flash memory, and / or some other suitable types of memory. Memory 606 may include hard disks, magnetic disks, optical disks, magneto-optical disks, solid-state drives, microelectromechanical systems (MEMS) based storage media, nanotechnology-based storage media, and / or some other suitable disks. Memory 606 may include drives for reading from and writing to the storage media. Memory 606 may be external to and / or removable from processing unit 600, for example, such as a Universal Serial Bus (USB) memory stick, dongle, hard disk, mass storage device, offline storage device, or some other type of storage media (e.g., CD, DVD, Blu-ray disc, etc.). The memory 606 may store data, software and / or instructions related to the operation of the touch sensing system 100.

[0038] Communication interface 612 enables processing unit 600 to communicate with other devices, networks, systems, sensors, etc., on the network. Communication interface 612 may include one or more wireless interfaces and / or wired interfaces. For example, communication interface 612 may include one or more transmitters and receivers, or transceivers. Communication interface 612 can operate according to protocol stacks and communication standards. In some embodiments, communication interface 612 includes an antenna. Communication interface 612 may include various processing logic or circuitry (e.g., multiplexing / demultiplexing, filtering, amplification, conversion, error correction, etc.). In some embodiments, communication interface 612 operates using one or more of long-range wireless protocols, short-range wireless protocols, or wired protocols.

[0039] In some embodiments, input device 608 allows input to processing unit 600. For example, input device 608 may include a keyboard, mouse, display, touchscreen, non-touchscreen, button, switch, input port, voice recognition logic, and / or other suitable visual, auditory, or tactile input components. Touch sensor array 102 may be incorporated into input device 608. Output device 610 allows output from processing unit 600. For example, output device 610 may include a speaker, display, touchscreen, non-touchscreen, projection display, lamp, output port, and / or other suitable visual, auditory, or tactile output components.

[0040] Figure 7 Embodiment 700 of a computer-readable medium 702 according to some embodiments is shown. One or more embodiments relate to a computer-readable medium including processor-executable instructions configured to implement one or more of the techniques presented herein. Embodiment 700 includes a non-transitory computer-readable medium 702 (e.g., a CD-R, DVD-R, flash drive, hard disk platter, etc.) thereon encoded computer-readable data 704. The computer-readable data 704 further includes a set of processor-executable computer instructions 706, which, when executed by a computing device 708 including a reader 710 for reading the processor-executable computer instructions 706 and a processor 712 for executing the processor-executable computer instructions 706, are configured to facilitate operation according to one or more of the principles set forth herein. In some embodiments, the processor-executable computer instructions 706, when executed, are configured to facilitate the execution of a method 714, such as at least some of the methods described above. In some embodiments, the processor-executable computer instructions 706, when executed, are configured to facilitate the implementation of a system, such as at least some of one or more of the aforementioned systems. Those skilled in the art can design many such computer-readable media configured to operate according to the techniques presented herein.

[0041] In an embodiment of the technology proposed herein, a method for touch detection includes: determining a first phase offset for a first unit cell of a touch sensor array; determining a second phase offset for a second unit cell of the touch sensor array; and setting a phase offset parameter of the touch sensor array based on the first phase offset and the second phase offset.

[0042] In the embodiments of the technology proposed herein, the touch sensor array includes a transmit line and a receive line, a unit cell is defined at the intersection of the transmit line and the receive line, and the phase offset parameter includes a phase offset parameter of the transmit signal applied to the transmit line.

[0043] In an embodiment of the technology proposed herein, the touch sensor array includes a transmit line and a receive line, defining a unit cell at the intersection of the transmit line and the receive line, and the phase offset parameter includes the phase offset of the demodulator reference signal applied to the output of the receive line.

[0044] In an embodiment of the technology proposed herein, the touch sensor array includes a transmit line and a receive line, defining a unit cell at the intersection of the transmit line and the receive line, a first unit cell located at a first end of a selected transmit line, a second unit cell located at a second end of a selected transmit line, and a phase offset parameter including a phase offset of a transmit signal applied to a selected transmit line.

[0045] In an embodiment of the technology proposed herein, a touch sensor array includes transmit lines and receive lines, defining unit cells at the intersection of the transmit lines and receive lines. A first unit cell is located at a first end of a selected receive line, and a second unit cell is located at a second end of a selected receive line. The selected receive line is connected to a sensing channel, which includes an analog-to-digital converter (ADC) and a demodulator. The demodulator is configured to multiply the output of the ADC by a demodulator reference signal, and a phase offset parameter includes a phase offset of the demodulator reference signal.

[0046] In the implementation of the technology proposed herein, determining the first phase offset includes using a touch panel model to determine the first phase offset, and determining the second phase offset includes using a touch panel model to determine the second phase offset.

[0047] In an embodiment of the technology proposed herein, a touch detection system includes: a touch sensor array including a transmit line, a receive line, and unit cells defined at the intersection of the transmit line and the receive line; a transmit sequencer configured to generate transmit signals on the transmit lines; an analog-to-digital converter module configured to measure the response of the unit cells to the transmit signals; and a calibration unit configured to determine a first phase offset for the first unit cell based on a first response in the response of the first unit cell, determine a second phase offset for the second unit cell based on a second response in the response of the second unit cell, and set phase offset parameters of the touch sensor array based on the first phase offset and the second phase offset.

[0048] In the implementation of the technology proposed herein, the phase offset parameter includes the phase offset parameter of the transmitted signal.

[0049] In an embodiment of the technology proposed herein, the touch detection system includes a demodulator connected to an analog-to-digital converter module, wherein the phase offset parameter includes the phase offset parameter of the demodulator.

[0050] In the implementation of the technology proposed herein, the demodulator is configured to multiply the output of the analog-to-digital converter module by a demodulator reference signal, and the phase offset parameter includes the phase offset of the demodulator reference signal.

[0051] In the implementation of the technology proposed herein, the first unit cell is located at a first end of a selected transmission line in the transmission line, the second unit cell is located at a second end of a selected transmission line in the transmission line, and the phase offset parameter includes the phase offset of the transmission signal applied to the selected transmission line in the transmission line.

[0052] In an embodiment of the technology proposed herein, a first unit cell is located at a first end of a selected receiver line in a receiver line, a second unit cell is located at a second end of a selected receiver line in a receiver line, the selected receiver line in the receiver line is connected to a sensing channel, the sensing channel includes an analog-to-digital converter and a demodulator, the demodulator is configured to multiply the output of the analog-to-digital converter by a demodulator reference signal, and the phase offset parameter includes the phase offset of the demodulator reference signal.

[0053] In an implementation of the technology proposed herein, the sensing channel includes a filter connected to a demodulator, which is configured to generate a response of a selected receiving line in the receiving line based on the output of the demodulator.

[0054] In the implementation of the technology proposed herein, the calibration unit is configured to determine a first phase offset using a touch panel model, and to determine a second phase offset using a touch panel model.

[0055] In an embodiment of the technology proposed herein, an apparatus includes: a display including a touch sensor array having a transmit line, a receive line, and unit cells defined at the intersections of the transmit and receive lines; a transmit sequencer configured to generate transmit signals for the transmit lines of the touch sensor array; an analog-to-digital converter module configured to measure the response of the receive lines to the transmit signals; and a calibration unit configured to determine a first phase offset of a first unit cell based on a first response in the response of a first unit cell in the unit cells, to determine a second phase offset of a second unit cell based on a second response in the response of a second unit cell in the unit cells, and to set a phase offset parameter for at least one of the transmit lines or the receive lines based on the first and second phase offsets.

[0056] In an embodiment of the technology proposed herein, the device includes a demodulator connected to an analog-to-digital converter module, wherein the phase offset parameter includes the phase offset parameter of the demodulator.

[0057] In the implementation of the technology proposed herein, the demodulator is configured to multiply the output of the analog-to-digital converter module by a demodulator reference signal, and the phase offset parameter includes the phase offset of the demodulator reference signal.

[0058] In the implementation of the technology proposed herein, the first unit cell is located at a first end of a selected transmission line in the transmission line, the second unit cell is located at a second end of a selected transmission line in the transmission line, and the phase offset parameter includes the phase offset of the transmission signal in the transmission signal applied to the selected transmission line in the transmission line.

[0059] In an embodiment of the technology proposed herein, the apparatus includes a sensing channel connected to a selected receiving line in a receiving line, comprising: an analog-to-digital converter in an analog-to-digital converter module; a demodulator configured to multiply the output of the analog-to-digital converter by a demodulator reference signal; and a filter connected to the demodulator configured to generate a response of the selected receiving line in the receiving line based on the output of the demodulator, wherein a first unit cell is located at a first end of the selected receiving line in the receiving line, a second unit cell is located at a second end of the selected receiving line in the receiving line, and a phase offset parameter includes a phase offset of the demodulator reference signal.

[0060] In the implementation of the technology proposed herein, the calibration unit is configured to determine a first phase offset using a touch panel model, and to determine a second phase offset using a touch panel model.

[0061] The term "computer-readable medium" can include communication media. Communication media typically implement computer-readable instructions or other data in a "modulated data signal" such as a carrier chip or other transmission mechanism, and include any information delivery medium. The term "modulated data signal" can include a signal whose characteristics are set or altered in a manner that encodes information in the signal.

[0062] Any aspect or design described herein as an “example” or similar is not necessarily to be construed as superior to other aspects or designs. Rather, the use of the word “example” is intended to present a possible aspect and / or implementation that may relate to the technology presented herein. Such examples are not necessary for such technology or are intended to be limiting. Various implementations of such technology may include such examples, alone or in combination with other features, and / or the examples shown may be modified and / or omitted.

[0063] Various operations of the embodiments are provided herein. In the embodiments, one or more of the described operations may constitute computer-readable instructions stored on one or more computer-readable media, which, if executed by a computing device, will cause the computing device to perform the described operations. The order in which some or all of the operations are described should not be construed as implying that these operations are necessarily sequentially related. Alternative orderings may be implemented without departing from the scope of this disclosure. Furthermore, it should be understood that not all operations are required to be present in every embodiment provided herein. Furthermore, it should be understood that in some embodiments, not all operations are necessary.

[0064] Although the subject matter has been described in language specific to structural features and / or methodological actions, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as examples of implementing at least some of the claims.

[0065] As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless otherwise stated or clearly indicated by the context, "X samples A or B" is intended to mean any natural inclusive arrangement. That is, if X takes A; X takes B; or X takes both A and B, then "X takes A or B" is satisfied in any of the foregoing cases. Additionally, unless otherwise stated or clearly indicated by the context, the articles "a" and "an" as used in this application and the appended claims are generally to be interpreted as meaning "one or more". Furthermore, unless otherwise stated, "first", "second", etc., are not intended to imply temporal, spatial, or sequential aspects. Rather, such terms are used only as identifiers, names, etc., of features, elements, items, etc. For example, a first element and a second element generally correspond to element A and element B, or two different or two identical elements, or the same element.

[0066] Furthermore, although this disclosure has been shown and described with respect to one or more embodiments, equivalent variations and modifications will occur to those skilled in the art upon reading and understanding of this specification and drawings. This disclosure includes all such modifications and variations and is limited only by the scope of the appended claims. In particular, with respect to the various functions performed by the aforementioned components (e.g., elements, resources, etc.), unless otherwise indicated, the terminology used to describe such components is intended to correspond to any component that performs the specified function of the described component (e.g., is functionally equivalent), even if it is not structurally equivalent to the disclosed structure that performs the function of the example implementations of this disclosure shown herein. Additionally, while certain features of this disclosure may have been disclosed with respect to only one of several implementations, such features may be combined with one or more other features of other implementations, as may be desired and advantageous for any given or particular application. Furthermore, to the extent that the terms “includes,” “having,” “has,” “with,” or variations thereof are used in the detailed description or claims, such terms are intended to be inclusive rather than encompassing, similar to “comprising.”

Claims

1. A method for touch detection, comprising: Determine the first phase offset for the first unit cell of the touch sensor array; Determine the second phase offset for the second unit cell of the touch sensor array; as well as The phase offset parameters of the touch sensor array are set based on the first phase offset and the second phase offset.

2. The method according to claim 1, wherein: The touch sensor array includes transmitting lines and receiving lines; A unit cell is defined at the intersection of the transmitting line and the receiving line; and The phase offset parameter includes the phase offset parameter of the transmitted signal applied to the transmit line.

3. The method according to claim 1, wherein: The touch sensor array includes transmitting lines and receiving lines; A unit cell is defined at the intersection of the transmitting line and the receiving line; and The phase offset parameter includes the phase offset of the demodulator reference signal applied to the output of the receiving line.

4. The method according to claim 1, wherein: The touch sensor array includes transmitting lines and receiving lines; A unit cell is defined at the intersection of the transmitting line and the receiving line; The first unit cell is located at the first end of a selected transmission line in the transmission lines; The second unit cell is located at the second end of the selected transmission line in the transmission line; and The phase offset parameter includes the phase offset of the transmitted signal applied to the selected transmit line in the transmit line.

5. The method according to claim 1, wherein: The touch sensor array includes transmitting lines and receiving lines; A unit cell is defined at the intersection of the transmitting line and the receiving line; The first unit cell is located at the first end of a selected receiving line in the receiving line; The second unit is located at the second end of the selected receiving line in the receiving line; The selected receiving line in the receiving line is connected to a sensing channel, the sensing channel comprising: Analog-to-digital converters; and A demodulator, configured to multiply the output of the analog-to-digital converter by a demodulator reference signal; and The phase offset parameter includes the phase offset of the demodulator reference signal.

6. The method according to claim 1, wherein: Determining the first phase offset includes using a touch panel model to determine the first phase offset; and Determining the second phase offset includes using the touch panel model to determine the second phase offset.

7. A touch detection system, comprising: A touch sensor array, comprising: Send line; Receive line; and The unit cell defined at the intersection of the transmitting line and the receiving line; A sequencer is configured to generate a transmission signal on the transmission line; An analog-to-digital converter module configured to measure the response of the unit cell to the transmitted signal; and The calibration unit is configured to: A first phase offset for the first unit is determined based on a first response in the response of the first unit in the unit cell; A second phase offset for the second unit is determined based on a second response in the response of the second unit in the unit cell; and The phase offset parameters of the touch sensor array are set based on the first phase offset and the second phase offset.

8. The touch detection system according to claim 7, wherein: The phase offset parameter includes the phase offset parameter of the transmitted signal.

9. The touch detection system according to claim 7, comprising: A demodulator, which is connected to the analog-to-digital converter module, wherein: The phase offset parameter includes the phase offset parameter of the demodulator.

10. The touch detection system according to claim 9, wherein: The demodulator is configured to multiply the output of the analog-to-digital converter module by a demodulator reference signal; and The phase offset parameter includes the phase offset of the demodulator reference signal.

11. The touch detection system according to claim 7, wherein: The first unit cell is located at the first end of a selected transmission line in the transmission lines; The second unit cell is located at the second end of the selected transmission line in the transmission line; and The phase offset parameter includes the phase offset of the transmitted signal applied to the selected transmit line in the transmit line.

12. The touch detection system according to claim 7, wherein: The first unit cell is located at the first end of a selected receiving line in the receiving line; The second unit is located at the second end of the selected receiving line in the receiving line; The selected receiving line in the receiving line is connected to a sensing channel, the sensing channel comprising: Analog-to-digital converters; and A demodulator, configured to multiply the output of the analog-to-digital converter by a demodulator reference signal; and The phase offset parameter includes the phase offset of the demodulator reference signal.

13. The touch detection system according to claim 12, wherein: The sensing channel includes: A filter connected to the demodulator is configured to generate the response of the selected receiver line among the receiver lines based on the output of the demodulator.

14. The touch detection system according to claim 7, wherein: The calibration unit is configured to: The first phase offset is determined using a touch panel model; and The second phase offset is determined using the touch panel model.

15. A display device, comprising: A display comprising a touch sensor array having a transmitting line, a receiving line, and a unit cell defined at the intersection of the transmitting line and the receiving line; A sequencer is configured to generate transmission signals for the transmission lines of the touch sensor array; An analog-to-digital converter module configured to measure the response of the receiving line to the transmitted signal; as well as The calibration unit is configured to: A first phase offset for the first unit is determined based on a first response in the response of the first unit in the unit cell; A second phase offset for the second unit is determined based on a second response in the response of the second unit in the unit cell; as well as The phase offset parameters for at least one of the transmit lines or the receive lines are set based on the first phase offset and the second phase offset.

16. The display device according to claim 15, comprising: A demodulator, which is connected to the analog-to-digital converter module, wherein: The phase offset parameter includes the phase offset parameter of the demodulator.

17. The display device according to claim 16, wherein: The demodulator is configured to multiply the output of the analog-to-digital converter module by a demodulator reference signal; and The phase offset parameter includes the phase offset of the demodulator reference signal.

18. The display device according to claim 15, wherein: The first unit cell is located at the first end of a selected transmission line in the transmission lines; The second unit cell is located at the second end of the selected transmission line in the transmission line; and The phase offset parameter includes the phase offset of the transmitted signal in the transmitted signal applied to the selected transmitted line in the transmitted line.

19. The display device according to claim 15, comprising: A sensing channel connected to a selected receiving line in the receiving line includes: The analog-to-digital converter module contains the analog-to-digital converter; A demodulator, configured to multiply the output of the analog-to-digital converter by a demodulator reference signal; and A filter connected to the demodulator is configured to generate the response of the selected receiver line among the receiver lines based on the output of the demodulator, wherein: The first unit cell is located at the first end of the selected receiving line in the receiving line; The second unit cell is located at the second end of the selected receiving line in the receiving line; and The phase offset parameter includes the phase offset of the demodulator reference signal.

20. The display device according to claim 15, wherein: The calibration unit is configured to: The first phase offset is determined using a touch panel model; and The second phase offset is determined using the touch panel model.

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