Angle detection for passive dials attached to touch screens

Abstract

A touchscreen display and corresponding devices and methods are disclosed, the touchscreen display including a touchscreen having a plurality of capacitance sensors and a passive dial having one or more conductive elements mounted within an active area of ​​the touchscreen proximate a surface of the touchscreen and adapted to move with rotation of the passive dial. The touchscreen display may further include a touchscreen controller that detects the angle of the passive dial using conventional capacitance sensing technology.

Description

[Technical field]

[0001] Related Applications This application is an international application of U.S. Provisional Patent Application No. 16 / 826,723, filed March 23, 2020, which claims priority to U.S. Provisional Patent Application No. 62 / 885,029, filed August 9, 2019, both of which are incorporated herein in their entireties.

[0002] The present disclosure relates generally to sensing systems, and more particularly to capacitance measurement systems that can be configured to determine the angle or position of a passive device on a touch screen display. [Background technology]

[0003] A touch screen display typically includes a touch screen that uses capacitive, resistive, inductive, optical, acoustic or other technologies to determine the presence, position or movement of one or more fingers, styluses and / or other objects. For example, a capacitive sensing array works by measuring the capacitance of a capacitive sensing element and evaluating a delta in capacitance that indicates the touch or presence of a conductive object. When a conductive object (e.g., a finger, hand or other object) touches or is in proximity to a capacitive sensing element, the capacitance changes and the conductive object is detected. A capacitive sensing system can sense an electrical signal generated at an electrode that reflects the change in capacitance. Such a change in capacitance can indicate a touch event (i.e., the proximity of an object to a respective electrode). The change in capacitance can be measured by an electrical circuit that converts a signal corresponding to the measured capacitance of the capacitive sensing element into a digital value. The measured capacitance is typically received as a current or voltage that is integrated and converted into a digital value.

[0004] There are two typical types of capacitance: 1) mutual capacitance, where a capacitive sensing circuit measures the capacitance formed between two electrodes coupled to the capacitive sensing circuit, and 2) self-capacitance, where a capacitive sensing circuit measures the capacitance of one electrode. Touch panels have both types of (1) and (2) distributed capacitive loads, and some touch solutions sense both capacitances uniquely or in a hybrid fashion in various sensing modes.

[0005] Capacitive sensing elements can be used for the replacement of mechanical buttons, dials / knobs, and other similar mechanical user interface controllers. The use of such sensing elements can replace the functionality of complex mechanical switches and buttons while providing reliable operation under harsh conditions. In addition, these sensing elements are widely used in modern consumer applications to provide user interface options for existing products. These sensing elements can range from a single button to multiple arrangements in the form of capacitive sensing arrays for touch sensing surfaces.

[0006] Sensing arrays and touch buttons are ubiquitous in today's industrial and consumer markets: they can be found in mobile phones, GPS devices, set-top boxes, cameras, computer screens, MP3 players, digital tablets, and more.

[0007] Embodiments of the present invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. [Brief description of the drawings]

[0008] [Figure 1A] FIG. 1 is a block diagram illustrating a capacitive touch screen display according to some embodiments of the present disclosure. [Figure 1B] FIG. 2 is a block diagram illustrating a capacitive touch screen display with a passive dial attached, according to some embodiments of the present disclosure. [Figure 2A] FIG. 1 illustrates a passive dial according to some embodiments of the present disclosure. [Figure 2B] FIG. 1 illustrates a passive dial according to some embodiments of the present disclosure. [Figure 3A] FIG. 2 illustrates a reference response paraboloid for a touch screen according to some embodiments of the present disclosure. [Figure 3B] FIG. 2 illustrates a reference response paraboloid for a touch screen according to some embodiments of the present disclosure. [Figure 4A] 1A-1C illustrate actual and reference responses of a touchscreen at different angles, according to some embodiments of the present disclosure. [Figure 4B] 1A-1C illustrate actual and reference responses of a touchscreen at different angles, according to some embodiments of the present disclosure. [Figure 4C] 1A-1C illustrate actual and reference responses of a touchscreen at different angles, according to some embodiments of the present disclosure. [Figure 4D] 1A-1C illustrate actual and reference responses of a touchscreen at different angles, according to some embodiments of the present disclosure. [Figure 5A] FIG. 13 illustrates a correlation coefficient for each angle of the dial, according to some embodiments of the present disclosure. [Figure 5B] FIG. 13 illustrates a correlation coefficient for each angle of the dial, according to some embodiments of the present disclosure. [Figure 5C] FIG. 13 illustrates a correlation coefficient for each angle of the dial, according to some embodiments of the present disclosure. [Figure 5D] FIG. 13 illustrates a correlation coefficient for each angle of the dial, according to some embodiments of the present disclosure. [Figure 6] FIG. 1 is a flow diagram illustrating a method for detecting a dial angle according to some embodiments of the present disclosure. [Figure 7] FIG. 11 is a flow diagram illustrating a method for detecting an initial movement of a dial according to some embodiments of the present disclosure. [Figure 8]FIG. 1 illustrates a reference response modeled as a Gaussian, in accordance with some embodiments of the present disclosure. [Figure 9] FIG. 1 illustrates a dial with multiple conductive elements according to some embodiments of the present disclosure. [Figure 10] FIG. 2 illustrates a touch screen display according to some embodiments of the present disclosure. [Figure 11] FIG. 1 illustrates a system for calibrating a touchscreen display and a system for operating a touchscreen display according to some embodiments of the disclosure. [Figure 12] FIG. 1 illustrates an embodiment of a core architecture of a Programmable System-on-Chip (PSoC®) processing device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present embodiments. However, it will be apparent to one skilled in the art that the present embodiments may be practiced without these specific details. In other instances, well-known circuits, structures and techniques are shown in block diagram form without detailed illustrations in order not to unnecessarily obscure an understanding of this description.

[0010] References in this description to "one embodiment" or "an embodiment" mean that each particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment. The appearances of the phrase "in one embodiment" in various places in this description do not necessarily refer to the same embodiment.

[0011] Capacitive sensing arrays and touch buttons are widespread in today's industrial and consumer markets. Capacitive sensing elements can be used to replace the functionality of mechanical buttons, dials / knobs and other similar mechanical user interface controllers. Nevertheless, dials remain a popular option among users in many applications, e.g., automobiles, due to their inherent tactile preferences and human habitual preferences. However, in vehicles and other applications, the increasing size of touchscreens often reduces the space available for dials. In addition, a separate dial may become redundant, as the touchscreen may replace the functionality of the dial.

[0012] The embodiments described herein are directed to detecting the angle of a passive dial attached to a touch screen display using conventional capacitive sensing techniques. The dial can be a passive device and thus need not include any kind of electronics (e.g., an on-board measurement system) or be powered in any way. The dial can include a conductive element that can be attached to the dial in close proximity to the touch screen. In this manner, the conductive element can be electrically or capacitively coupled to the touch screen so that its angle can be detected. When the dial is rotated, the conductive element can rotate, and thus the rotation and current angle of the conductive element (and thus the dial) can be detected by the capacitive sensing array. The embodiments described herein also include detecting and removing negative parasitic responses resulting from the initial movement of the dial. The passive nature of the dial allows the embodiments described herein to be robust to noise and less susceptible to capacitance measurement drift due to temperature, as described in more detail herein. Additionally, there is no radius jitter because the angular position is calculated directly (i.e., the angular position is the primary variable). Other advantages may be realized instead of or in addition to those set forth herein.

[0013] Described herein are devices, methods and systems for determining a position of a passive dial attached to a touchscreen display using conventional capacitive sensing technology. In one embodiment, a touchscreen display is disclosed, comprising a touchscreen having a plurality of capacitive sensors and a passive dial having one or more conductive elements. The passive dial can be mounted within an active area of ​​the touchscreen such that the one or more conductive elements are proximate to a surface of the touchscreen and move with rotation of the passive dial. The touchscreen display can further comprise a touchscreen controller operably coupled to the touchscreen. The touchscreen controller can detect an angle of the passive dial as the passive dial rotates based at least in part on a capacitive response of each of a set of a plurality of capacitive sensors to the one or more conductive elements, and output data corresponding to the angle of the passive dial to a user interface controller.

[0014] Although described with respect to a capacitive sensing system, embodiments of the present disclosure may be implemented with a touch screen display utilizing any suitable sensing system (eg, inductive, resistive).

[0015] For example, an inductive sensing system may include one or more sensing elements that tap the loop current induced by a resonating coil or pair of coils, where some combination of the current magnitude, phase and frequency can be used to determine position information.

[0016] In another example, a resistive sensing system can include a first layer that is flexible and conductive and separated from a second conductive layer by one or more spacer elements. During operation, one or more voltage gradients are created across the layers. Pressing on the flexible first layer can cause the first layer to deflect sufficiently such that electrical contact is made between the layers, resulting in voltage outputs that reflect the points of contact between the layers. These voltage outputs can be used to determine position information.

[0017] FIG. 1A is a block diagram illustrating one embodiment of a touchscreen display 100. The touchscreen display 100 can include a touchscreen 105, a user interface controller 140 (FIG. 1B), and a touchscreen controller 120. The touchscreen 105 can include a capacitive sensing array 110, and the touchscreen controller 120 can be configured to measure the capacitance (self-capacitance or mutual capacitance) of the capacitive sensing array 110. In one embodiment, a multiplexer circuit can be used to connect the capacitive sensing circuit 125 of the touchscreen controller 120 to the sensing array 110 in various configurations. The touchscreen 105 (e.g., a touchscreen or touchpad) can be coupled to the touchscreen controller 120, which can be coupled to a host computing device (not shown). In one embodiment, the sensing array 110 is a two-dimensional sensing array that detects touches on the touchscreen 105 using the touchscreen controller 120.

[0018] In one embodiment, the sensing array 110 includes electrodes 111(1)-111(N), where N is a positive integer, arranged as a two-dimensional matrix (also referred to as an XY matrix). The sensing array 110 is coupled to the touch screen controller 120 via one or more analog buses 115 carrying multiple signals. In further embodiments, multiplexers (not shown) can be used to couple the capacitive sensing circuits 125 in various configurations as described herein. The capacitive sensing array 110 can include a multi-dimensional capacitive sensing array. The multi-dimensional sensing array includes multiple sensing elements organized as rows and columns. In another embodiment, the capacitive sensing array 110 operates as an all-points-addressable ("APA") mutual capacitance sensing array. In yet another embodiment, the capacitive sensing array 110 is an opaque capacitive sensing array (e.g., a PC touchpad). The capacitive sensing array 110 can be arranged to have a flat surface profile. Alternatively, the capacitive sensing array 110 may have a non-flat surface profile. Alternatively, other configurations of capacitive sensing arrays may be used. For example, instead of vertical columns and horizontal rows, the capacitive sensing array 110 may have a hexagonal arrangement, etc., as would be understood by one of ordinary skill in the art having the benefit of this disclosure. In one embodiment, the capacitive sensing array 110 may be included in a panel or touch screen panel made, for example, from indium tin oxide (ITO) or any other transparent conductor.

[0019] In one embodiment, the capacitance sensing circuit 125 may include one or more receive (RX) channels for measuring the charge on the electrodes 111. There are various ways to measure the capacitance on the capacitance sensing array 110, such as self-capacitance sensing and mutual capacitance sensing. The RX channel may include a relaxation oscillator or other means for measuring the capacitance and a counter or timer for measuring the oscillator output. In another embodiment, the RX channel includes a computational amplifier, a switch, and an integrator capacitor, as described and illustrated with respect to FIG. 2. The RX channel measures a signal representative of the self-capacitance of the electrodes 111(1)-111(N). The capacitance sensing circuit 125 also includes a converter circuit, such as an analog-to-digital converter (ADC), that converts the measured signal to a digital value. The touch screen controller 120 may further include a software component that converts the count value (e.g., capacitance value) to a touch detection decision (also referred to as a switch detection decision) or a relative amplitude. It should be noted that there are various known methods for measuring capacitance, such as current vs. voltage phase shift measurement, resistor-capacitor charging timing, capacitive bridge divider, charge transfer, successive approximation, sigma-delta modulator, charge storage circuit, field effect, mutual capacitance, frequency shift, or other capacitance measurement algorithms. However, it should be noted that in some embodiments, instead of evaluating the raw count against a threshold, the capacitance sensing circuit 125 may evaluate other measurements to determine user interaction. For example, in a capacitance sensing circuit 125 with a sigma-delta modulator, the capacitance sensing circuit 125 evaluates the ratio of the pulse widths of the output (i.e., density area) instead of the raw count being above or below a certain threshold. It should be noted that the RX channel may be one type of sensing channel that may be configured for different modes of operation. For example, the RX channel in self-capacitance mode is configured as a sensing channel for driving and sensing an electrode to measure the self-capacitance of the electrode to ground. The RX channel can also be configured as a sensing channel for a mutual capacitance mode to measure the mutual capacitance between a first electrode (RX) and a second electrode (TX).The TX electrodes in this mode are driven by the TX signal as described herein. Alternatively, the RX channel can be configured in a self-capacitance and mutual capacitance mode, in which the self-capacitance and mutual capacitance may be measured simultaneously or sequentially.

[0020] In another embodiment, the capacitive sensing circuit 125 may include a TX signal generator for generating a TX signal 125A applied to the TX electrodes, and a receiver (also referred to as a sensing channel), such as an integrator, coupled to measure the RX signal 125B on the RX electrodes. In a further embodiment, the capacitive sensing circuit includes an analog-to-digital converter (ADC) coupled to an output of the receiver to convert the measured RX signal into a digital value representing the capacitance value. The digital value may be further processed by the touch screen controller 120.

[0021] The touch screen controller 120 is configured to detect one or more conductive objects in contact with or in proximity to the touch screen 105. As used herein, "touch" may mean a conductive object in contact with or in proximity to the touch screen 105. The touch screen controller 120 may detect a conductive object such as a finger, a passive stylus, an active stylus, or any combination thereof. The capacitive sensing circuit 125 may measure touch data on the capacitive sensing array 110. The touch data may be represented as a number of cells, with each cell representing an intersection of sensing elements (e.g., electrodes) of the capacitive sensing array 110. An intersection between two sensing elements may be understood as a location where one sensing electrode crosses or overlaps another sensing electrode while maintaining galvanic isolation from each other.

[0022] The capacitive sensing element 111 is an electrode of a conductive material such as copper. The sensing element 111 may also be part of a panel made from ITO or any other transparent or semi-transparent conductive material. The capacitive sensing element 111 may be configurable to allow the capacitive sensing circuit 125 to measure self-capacitance, mutual capacitance, or any combination thereof. In another embodiment, the touch data is a two-dimensional capacitance image of the capacitive sensing array 110. In one embodiment, once the capacitive sensing circuit 125 measures the mutual capacitance of a touch sensing device (e.g., the capacitive sensing array 110), the capacitive sensing circuit 125 obtains a 2D capacitance image of the touch sensing device and processes the data for peaks and position information. In another embodiment, the touchscreen controller 120 is a microcontroller that obtains a data set of capacitive touch signals, such as from the sensing array 110, and finger detection firmware running on the microcontroller identifies regions of the data set indicative of a touch, detects and processes peaks, calculates coordinates, or any combination thereof. The firmware identifies the peaks using the embodiments described herein. The firmware can calculate precise coordinates of the resulting peaks. In one embodiment, the firmware can calculate the exact coordinates of the resulting peak using a correlation algorithm that calculates a correlation coefficient for each possible angle and identifies the angle with the highest correlation coefficient as the location of the touch. The X / Y coordinates of the peak can describe the exact location of the touch, as described in more detail herein. Alternatively, other coordinate interpolation algorithms can be used to determine the coordinates of the resulting peak. The touchscreen controller 120 can report the exact coordinates, as well as other information, to the host 150 (e.g., a host processor).

[0023] In one embodiment, the touch screen controller 120 further includes a processing device 130. The operation of the processing device 130 may be implemented in firmware, or alternatively in hardware or software. The processing device 130 may receive signals from the capacitive sensing circuitry 125 and determine the state of the sensing array 110, such as whether an object (e.g., a finger) has been detected on or in proximity to the sensing array 110 (e.g., determining the presence of an object), where the object is on the sensing array (e.g., locating the object), tracking the movement of the object, or other information regarding the object detected by the touch sensor.

[0024] In another embodiment, instead of performing the operations of the processing device 130 of the touchscreen controller 120, the touchscreen controller 120 can send raw or partially processed data to the host 150. The host 150 can include a decision logic 151 that performs some or all of the operations of the processing device 130 as shown in FIG. 1. The operations of the decision logic 151 can be implemented in firmware, hardware, software, or a combination thereof. The host 150 can include a high-level application programming interface (API) to the application 152 that performs routines on the received data, such as compensation for sensitivity differences, other compensation algorithms, baseline update routines, start-up and / or initialization routines, interpolation or scaling operations, etc. The operations described with respect to the processing device 130 can be implemented in the decision logic 151, the application 152, or other hardware, software, and / or firmware external to the touchscreen controller 120. In some other embodiments, the touchscreen controller 120 is or includes the host 150.

[0025] In another embodiment, the touchscreen controller 120 may also include a non-sensing action block 103. This block 103 may be used to process and / or receive / transmit data to / from the host 150. For example, additional components (e.g., a keyboard, keypad, mouse, trackball, LEDs, displays, or other peripheral devices) may be implemented to operate with the touchscreen controller 120 in conjunction with the sensing array 110.

[0026] As shown, the capacitive sensing circuit 125 can be integrated into the touchscreen controller 120. The capacitive sensing circuit 125 can include analog I / O for coupling to external components such as touch sensor pads (not shown), the capacitive sensing array 110, touch sensor sliders (not shown), touch sensor buttons (not shown), and / or other devices. The capacitive sensing circuit 125 can be configurable to measure capacitance using mutual capacitance sensing techniques, self-capacitive sensing techniques, charge-coupled techniques, and the like. In one embodiment, the capacitive sensing circuit 125 operates using a charge storage circuit, a capacitance modulation circuit, or other capacitive sensing methods known by those skilled in the art. In an embodiment, the capacitive sensing circuit 125 is a Cypress TMA-4xx or TMA-xx family of touchscreen controllers. Alternatively, other capacitive sensing circuits may be used. The capacitive sensing arrays or touchscreens described herein can include a transparent conductive sensing array disposed on top of, within, or underneath either the visual display itself (e.g., LCD monitor) or a transparent substrate in front of the display.

[0027] In an embodiment, the TX and RX electrodes are arranged as rows and columns, respectively. It should be noted that the rows and columns of electrodes may be configured by the touchscreen controller 120 (or the capacitive sensing circuitry 125) in any combination as individual electrodes for self-capacitance measurements and as TX or RX electrodes for mutual capacitance measurements. Similarly, the touchscreen controller 120 (or the capacitive sensing circuitry 125) may configure electrodes as RX electrodes for self-capacitance sensing and one or more electrodes as barrier electrodes, such as through a multiplexer. In a further embodiment, the touchscreen controller 120 (or the capacitive sensing circuitry 125) may also be configured such that some electrodes are driven by a shield signal. An intersection between two sensing elements may be understood as a location where one sensing electrode crosses or overlaps another sensing electrode while maintaining galvanic isolation from one another. When a touch object, such as a finger or stylus, approaches the capacitive sensing array 110, the object causes a decrease in mutual capacitance between some of the TX / RX electrodes. In another embodiment, the presence of the finger increases the coupling capacitance of the electrodes. Thus, the location of the finger on the capacitive sensing array 110 can be determined by identifying the RX electrodes where the coupling capacitance between the TX and RX electrodes has decreased, to which the TX signal was applied at the time a decrease in capacitance was measured on the RX electrodes. Thus, the location of one or more inputs can be determined by sequentially determining the capacitance associated with the intersections of the electrodes. It is noted that the process can calibrate the sensing elements by determining the baseline of the sensing elements. It is also noted that, as will be appreciated by those skilled in the art having the benefit of this disclosure, interpolation can be used to detect the location of the finger with better resolution than the row / column pitch. In addition, as will be appreciated by those skilled in the art having the benefit of this disclosure, various types of coordinate interpolation algorithms can be used to detect the center of the touch.

[0028] It should also be noted that the embodiments described herein are not limited to having a configuration of a processing device coupled to a host, but can include a system that measures capacitance on a sensing device and transmits the raw data to a host computer where the data is analyzed by an application. Essentially, the processing performed by touchscreen controller 120 can also be performed in the host.

[0029] The touchscreen controller 120 may reside on a common carrier substrate, such as, for example, an integrated circuit (IC) die substrate or a multi-chip module substrate. Alternatively, the components of the touchscreen controller 120 may be one or more separate integrated circuits and / or discrete components. In one embodiment, the touchscreen controller 120 may be a Programmable System-on-Chip (PSoC®) processing device developed by Cypress Semiconductor Corporation (San Jose, Calif). Alternatively, the touchscreen controller 120 may be one or more other processing devices known by those skilled in the art, such as a microprocessor or central processing unit, a controller, a special purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable device. In an alternative embodiment, for example, the touchscreen controller 120 may be a network processor having multiple processors, including a core unit and multiple micro-engines. Additionally, the touchscreen controller 120 may include any combination of general purpose and special purpose processing devices.

[0030] The capacitive sensing circuit 125 may be integrated into the IC of the touch screen controller 120, or alternatively, may be integrated into another IC. Alternatively, a description of the capacitive sensing circuit 125 may be generated and compiled for incorporation into another integrated circuit. For example, behavioral level code describing the capacitive sensing circuit 125, or a portion thereof, may be generated using a hardware description language such as VHDL or Verilog, and stored on a machine-accessible medium (e.g., CD-ROM, hard disk, floppy disk, etc.). Additionally, the behavioral level code may be compiled into register transfer level ("RTL") code, a netlist, or a circuit layout, and stored on a machine-accessible medium. The behavioral level code, RTL code, netlist, and circuit layout may represent different levels of abstraction for describing the capacitive sensing circuit 125.

[0031] It should be noted that the components of the touchscreen display 100 may include all of the components described above. Alternatively, the touchscreen display 100 may include only some of the components described above.

[0032] In one embodiment, the touch screen display 100 is used in a tablet computer. Alternatively, the electronic device may be used in other applications, such as a notebook computer, a mobile handset, a personal digital assistant ("PDA"), a keyboard, a television, a remote controller, a monitor, a portable multimedia device, a portable media (audio and / or video) player, a portable gaming device, a signature input device for point-of-sale transactions, an e-book reader, a global positioning system ("GPS"), or a control panel. The embodiments described herein are not limited to touch screens or touch sensor pads for implementation in notebooks, but may be used in other capacitive sensing implementations, for example, the sensing devices may be touch sensor sliders (not shown) or touch sensor buttons (e.g., capacitive sensing buttons). In one embodiment, these sensing devices include one or more capacitive sensors or other types of capacitive sensing circuits. The operations described herein are not limited to notebook pointer operations, but may include operations such as lighting control (dimming), volume control, graphic equalizer control, speed control, or other control operations requiring stepwise or discrete adjustments. It should also be noted that these embodiments of capacitive sensing implementations can be used in conjunction with non-capacitive sensing elements, such as, but not limited to, pick buttons, sliders (e.g., display brightness and contrast), scroll wheels, multimedia controllers (e.g., volume, track advance, etc.), handwriting recognition and numeric keypad operation.

[0033] FIG. 1B illustrates the touchscreen display 100 of FIG. 1A with a dial 200 attached to the touchscreen 105. The dial 200 can be any suitable rotating mechanism (e.g., a knob) and can be attached to the active area of ​​the touchscreen 105 (e.g., where the capacitive sensor 111 is located). Although shown as being fully attached to the active area of ​​the touchscreen 105, the passive dial 200 may in some embodiments be partially attached to the active area of ​​the touchscreen 105 such that a portion of the passive dial 200 overlaps an area of ​​the touchscreen 105 that is not within the active area. The dial 200 can be attached in any suitable manner. In some embodiments, the dial 200 can include an acrylic panel adhered to the surface of the touchscreen 105. The dial 200 can be a passive device and need not include any type of electronics (e.g., an on-board measurement system) or be powered in any manner. FIGS. 2A and 2B illustrate bottom and side views of the dial 200 of FIG. 1B. The dial 200 can include a conductive element 205 (shown in FIGS. 2A and 2B and also referred to herein as a "finger simulator") that can be attached to the dial 200 in close proximity (e.g., 0.1-0.5 millimeters) to the touch screen 105. In this manner, the conductive element 205 can be electrically or capacitively coupled to the touch screen 105 such that the angle of the dial 200 can be detected. Rotating the dial 200 allows the conductive element 205 to rotate, such that the rotation and current angle of the conductive element 205 (and thus the dial 200) can be detected by the capacitive sensing array 110, as discussed herein.For example, the touchscreen controller 120 may obtain a data set of capacitive touch signals from the capacitive sensing array 110 resulting from rotation of the conductive element 205 through every angle (1-360), and position detection firmware executing on the touchscreen controller 120 may identify a region of the data set indicative of the angle of the conductive element 205 based on peaks in the data set, as discussed further herein. For example, the firmware may use a correlation algorithm to calculate the exact angle of the conductive element 205 and display the angle on the touchscreen 105 in any suitable manner. As used herein, the angle of a dial or conductive element may refer to the current angle of the dial or conductive element.

[0034] The conductive element 205 may be made of any suitable metal and may have any suitable shape (e.g., rectangular) although it is shown in Figures 2A and 2B as a cylinder. The dial 200 may include a rotating metal plate 215 and a trunk 210. The metal plate 215 may be made of any suitable metal and the trunk 210 may be made of metal, plastic or any other suitable material. The dial 200 may be passive, making it resistant to noise and less susceptible to grip fingers. Although shown as having a single conductive element, the dial 200 may include any suitable number of conductive elements.

[0035] Referring again to FIG. 1B, upon power-up of the touchscreen display 100, the touchscreen controller 120 can measure the raw count value of each capacitive sensor 111(1)-111(N) in the capacitive sensor array 110. The raw count of an individual capacitive sensor 111 can represent the measured sensor capacitance of that capacitive sensor. The touchscreen controller 120 can then initialize the baseline capacitance of each capacitive sensor 111 to the raw count (measured sensor capacitance) of that capacitive sensor 111. The baseline capacitance of a capacitive sensor 111 can represent the capacitance of the sensor without a user touch (e.g., no conductive element nearby). The touchscreen controller 120 assumes that no conductive element is nearby any of the capacitive sensors 111 when initializing the baseline capacitance of each capacitive sensor 111 to its raw count. The differential count for an individual capacitive sensor 111 can refer to the response of the capacitive sensor to a user touch / proximity to a conductive element and can be defined as the raw count minus the baseline capacitance of the capacitive sensor. The touchscreen controller 120 can continuously perform measurements of the raw count values ​​of each capacitive sensor 111(1)-111(N).

[0036] The touchscreen controller 120 may execute a correlation algorithm firmware, as discussed in more detail herein, to determine a correlation coefficient for each angle of the dial 200. The correlation coefficient for an individual angle may refer to a level of similarity between a measured difference count value of the matrix of the capacitive sensors 111 at that individual angle and a reference response value of the matrix of the capacitive sensors 111 at that individual angle of the dial 200. Thus, the touchscreen controller 120 may determine a correlation coefficient for an individual angle of the dial 200 based on a measured difference count value of the matrix of the capacitive sensors 111 at that individual angle and a reference response value of the matrix of the capacitive sensors 111 at that individual angle of the dial 200. Although discussed in terms of correlation coefficients, any suitable method of determining the similarity between a measured difference count value of the matrix of the capacitive sensors 111 at that individual angle and a reference response value of the matrix of the capacitive sensors 111 at that individual angle of the dial 200 may be used. For example, the touchscreen controller 120 can use a least mean square algorithm to determine the level of similarity between the measured difference count values ​​of the matrix of capacitive sensors 111 at a discrete angle and the reference response values ​​of the matrix of capacitive sensors 111 at that discrete angle of the dial 200. FIGS. 3A and 3B show a reference response 300 for a discrete angle of the dial 200. As shown in FIGS. 3A and 3B, the reference response 300 is modeled as a paraboloid with (X, Y, Z) coordinates. FIG. 3B shows an xy and xz view of the reference response 300 (each block of the xy view grid can represent a capacitive sensor 111), where O is the origin of the touchscreen, C is the center of rotation of the dial, R is the radius of the dial, and α is the rotation angle of the dial. The reference response 300 can represent an ideal capacitive response of the matrix of capacitive sensors (shown by the shaded sensors in FIG. 3B) at a discrete angle. In the example of Figure 3B, the matrix is ​​a 3x3 matrix centered on the center of the reference paraboloid indicated by the (X0,Y0) coordinates, which depends on the radius of the dial 200, as shown in Figure 3B.The baseline response for each angle of the dial 200 can be predetermined (e.g., during manufacture of the touchscreen display 100) and stored in the memory 135 of the touchscreen controller 120. The baseline paraboloid 300 can have two main tuning parameters: height (h) and radius (r). The r of the baseline paraboloid 300 can be adjusted to fit the sensor matrix of the capacitive sensors (in the example of FIG. 3B, a 3×3 sensor matrix) whose capacitive responses at each individual angle contribute to the measured capacitive response. The baseline response is ideally the same for each angle, but there may be slight variations from angle to angle. Note that a compensation algorithm may be used to normalize the response of the sensing electrodes for each position / angle to compensate for the widely differing baseline responses from angle to angle.

[0037] In this case, the touchscreen controller 120 can determine a measured difference count value for each possible angle of the dial 200. The measured difference counts for the discrete angles can refer to the measured difference count values ​​of a matrix of capacitive sensors 111 at discrete angles. The matrix of sensors can be defined as discussed above with respect to the reference response 300. FIGS. 4A and 4C show the measured difference count values ​​for two different angles of the dial 200, and FIGS. 4B and 4D show modeled reference response paraboloids for the same two angles of the dial 200. In this case, the touchscreen controller 120 can determine a correlation coefficient (K j ) for each angle j, i ) and the reference paraboloid coordinates of each angle j (X i ,Y i ,Z ij ), where i is the capacitive sensor matrix index (e.g., i=1...9 for a 3x3 capacitive sensor matrix) and j is the angle index (e.g., j=1...360). The touch screen controller 120 can identify the angle at which the correlation coefficient is maximum as the current angle of the dial 200. This can be done based on the equation, i.e. K max =MAX(Kj ) when α max =j (1) It can be expressed as:

[0038] The touch screen controller 120 can determine the correlation coefficient using the following equations:

number

[0039] 5A-5D show graphs of the correlation coefficient for each angle j (1...360). As shown, the angle at which the correlation coefficient is maximized corresponds to the position of the dial 200. FIGS. 5A-5D also show the angle at which the correlation coefficient is minimized (K min =MIN(K j ) which is expressed as follows: K j =MIN(K j ) when α neg =j (8) This can be shown as:

[0040] In some embodiments, the touchscreen controller 120 can use the angle at which the correlation coefficient is minimal to eliminate negative parasitic responses after power-on and initial movement. After the touchscreen display 100 is powered on, the touchscreen controller 120 can initialize the baseline capacitance of each capacitive sensor 111, including the capacitive sensor currently under (or in close proximity to) the conductive element 205 (finger simulator) of the dial 200, to the raw count of the sensor (as discussed herein). The baseline capacitance of the majority of the capacitive sensors 111 can be zero since their raw count (measured capacitance) was zero. However, for sensors that are under the conductive elements at the time of initialization, their raw count is a positive non-zero value (because they are responding to the conductive elements) and their baseline capacitance is initialized to this positive non-zero value. As a result, the difference count (difference count = raw count - baseline capacitance) for each capacitive sensor 111 is zero. However, after an initial rotation of the dial 200, the difference counts for the matrix of sensors around the new position of the conductive element 205 are positive, but the difference counts for the matrix of sensors around the old position of the conductive element 205 are persistently negative. This is because the new raw counts for the matrix of sensors around the old position are zero, but the baseline capacitance of these capacitive sensors was initialized to its previous positive value because the conductive element 205 was over the sensors during initialization. As a result, the correlation coefficient for this position is persistently negative. Thus, the (negative) difference counts (represented by the angle at which the correlation coefficient is minimal) for the matrix of sensors around the old position of the conductive element 205 form a negative parasitic peak, which may distort the detection of the main peak representing the maximum value of the correlation coefficient. The touch screen controller 120 can determine whether there has been an initial rotation of the dial 200, as discussed in more detail herein (e.g., with respect to FIG. 7).

[0041] Thus, in some embodiments, once the correlation algorithm firmware has been executed to determine the correlation coefficient for each angle of the dial 200, the touchscreen controller 120 can determine the correlation coefficient of the negative peak and apply a reset of the baseline capacitance for each capacitive sensor 111 in the sensor matrix around the position corresponding to the correlation coefficient of the negative peak. In other words, the touchscreen controller 120 can reinitialize the baseline capacitance of each capacitive sensor 111 in the sensor matrix to its current raw count value (after the initial movement of the dial 200). Once the baseline capacitance of each of these capacitive sensors 111 has been reinitialized, the touchscreen controller 120 can execute the correlation algorithm firmware to again determine the correlation coefficient for each angle of the dial 200. In this case, the touchscreen controller 120 can identify the angle at which the correlation coefficient is maximized as the angle of the dial 200. In this manner, the determination of the correlation coefficient peak is not affected by the parasitic negative peak discussed above. The touchscreen controller 120 may output data corresponding to the angle of the dial 200 to the user interface controller 140, which may display the angle on the touchscreen 105 in any suitable manner. In some embodiments, the data corresponding to the current angle of the dial 200 may include the current angle of the dial 200 as well as the change in angle from a previous position of the dial 200. In some embodiments, the touchscreen controller 120 may output data corresponding to the current angle of the dial 200 incrementally, for example, as the dial 200 is moved.

[0042] 6 is a flow diagram of a method 600 for determining a position of a passive dial using capacitive sensing, according to some embodiments. Method 600 can be implemented by processing logic, which may include hardware (e.g., circuitry, dedicated logic, programmable logic, processor, processing device, central processing unit (CPU), system on chip (SoC), etc.), software (e.g., instructions operating / executed on a processing device), firmware (e.g., microcode), or a combination thereof. For example, method 600 can be implemented by touchscreen controller 120 executing correlation algorithm firmware.

[0043] 1B, at block 605, upon power-on of the touchscreen display 100, the touchscreen controller 120 can measure the raw count value of each capacitive sensor 111(1)-111(N) in the capacitive sensor array 110. The raw count of an individual capacitive sensor 111 can represent the measured sensor capacitance of that capacitive sensor. Then, at block 610, the touchscreen controller 120 can initialize the baseline capacitance of each capacitive sensor 111 to the raw count (measured sensor capacitance) of that capacitive sensor 111. The baseline capacitance of the capacitive sensor 111 can represent the capacitance of the sensor without a user touch (e.g., no conductive element nearby). The touchscreen controller 120 assumes that no conductive element is nearby any of the capacitive sensors 111 when initializing the baseline capacitance of each capacitive sensor 111 to its raw count. The differential count for an individual capacitive sensor 111 may represent the response of the capacitive sensor to a user touch / proximity of a conductive element and may be defined as the raw count minus the baseline capacitance of the capacitive sensor. The touchscreen controller 120 may continuously perform measurements of the raw count values ​​of each capacitive sensor 111(1)-111(N).

[0044] At block 615, the touchscreen controller 120 may then continue to perform measurements of the raw count values ​​of each capacitive sensor 111(1)-111(N). At block 620, the touchscreen controller 120 may then execute correlation algorithm firmware to determine a correlation coefficient for each angular position of the dial 200, as discussed in more detail herein. At block 620, the touchscreen controller 120 may determine whether an initial movement of the dial 200 has been detected, as discussed further with respect to FIG.

[0045] If an initial movement of the dial 200 is detected in block 625, the touch screen controller 120 can use the angle at which the correlation coefficient is at a minimum to perform a baseline reset for the matrix of sensors around the angle at which the correlation coefficient is at a minimum to remove the negative parasitic response in block 630. As discussed herein, after the touch screen display 100 is powered on, the baseline capacitance of each capacitive sensor 111, including the capacitive sensor under the conductive element 205 (finger simulator) of the dial 200, is initialized to the raw count of that sensor. Thus, the difference count (difference count = raw count - baseline capacitance) for each capacitive sensor 111 will be zero. However, after an initial rotation of the dial 200, the difference count for the matrix of sensors around the new position of the conductive element 205 will be positive, while the difference count for the matrix of sensors around the old position of the conductive element 205 will be persistently negative. This is because the new raw counts for the matrix of sensors around the old position will be zero, but the baseline capacitance of these capacitive sensors was initialized to its previous positive value because the conductive element 205 was over the sensors during initialization. As a result, the correlation coefficient for this position will be persistently negative. Thus, the (negative) difference counts (represented by the angle at which the correlation coefficient is minimal) for the matrix of sensors around the old position of the conductive element 205 will form a negative parasitic peak, which may distort the detection of the main peak representing the maximum value of the correlation coefficient. The touch screen controller 120 can determine whether there has been an initial rotation of the dial 200, as discussed in more detail herein (e.g., with respect to FIG. 7).

[0046] Thus, in some embodiments, once the correlation algorithm firmware is executed to determine the correlation coefficient for each angle of the dial 200, the touchscreen controller 120 can determine the correlation coefficient of the negative peak and apply a reset of the baseline capacitance for each capacitive sensor 111 in the sensor matrix around the position corresponding to the correlation coefficient of the negative peak. In other words, the touchscreen controller 120 can reinitialize the baseline capacitance of each capacitive sensor in the sensor matrix to the current raw count value (after the initial movement of the dial 200). Once the baseline capacitance of each of these capacitive sensors 110 is reinitialized, the touchscreen controller 120 can execute the correlation algorithm firmware to again determine the correlation coefficient for each angle of the dial 200. In this case, the touchscreen controller 120 can identify the angle / position at which the correlation coefficient is maximized as the angle / position of the dial 200. In this way, the determination of the correlation coefficient peak is not affected by the parasitic negative peak discussed above.

[0047] Then, in block 635, the touch screen controller 120 can perform another raw count value measurement of each capacitive sensor 111(1)-111(N), and in block 640, the dial position can be determined using a correlation algorithm, as discussed herein (e.g., with respect to Figures 3 and 4).

[0048] 7 is a flow diagram of a method 700 for detecting an initial movement of a passive dial, according to some embodiments. Method 700 may be implemented by processing logic, which may include hardware (e.g., circuitry, dedicated logic, programmable logic, processor, processing device, central processing unit (CPU), system on chip (SoC), etc.), software (e.g., instructions operating / executed on a processing device), firmware (e.g., microcode), or a combination thereof. For example, method 700 may be implemented by touchscreen controller 120 executing correlation algorithm firmware.

[0049] In block 705, the touch screen controller 120 determines the maximum correlation coefficient (Max K j ) is greater than the peak detection threshold and the minimum correlation coefficient (Min K j ) is less than the negative peak detection threshold. If not, the touch screen controller 120 may determine that there has been no initial movement of the passive dial (block 710). If the touch screen controller 120 determines that the condition is met in block 705, then it may determine in block 715 whether the distance between the main peak and the negative average peak is greater than twice the radius of the reference paraboloid. If not, the touch screen controller 120 may determine that there has been no initial movement of the passive dial (block 710). If the touch screen controller 120 determines that the condition is met in block 715, then it may determine that there has been an initial movement of the passive dial (block 720).

[0050] In some embodiments, the reference response 300 of FIG. 3 can be modeled as a Gaussian instead of a paraboloid. A Gaussian reference model may have a greater similarity to the response of the actual conductive element, but may involve more complex and processor-intensive mathematical calculations. FIG. 8 shows the reference response 300 modeled as a Gaussian in a three-dimensional (X,Y,Z) coordinate system. The touch screen controller 120 can calculate the correlation coefficient as above for the reference response modeled as a paraboloid (as discussed with respect to FIG. 3), but with the Gaussian model height (Z) being the focal length. i )teeth, z i =he{(x i -x 0 ) 2 +(y i -y 0 ) 2} / 2c 2 (9) It may be calculated as follows.

[0051] In the above equation, c can denote the radius coefficient of the Gaussian.

[0052] In some embodiments, the dial 200 can include more than one conductive element. For example, the dial 200 can include four or more conductive elements randomly distributed on the dial 200 at pseudo-random distances from each other. FIG. 9 shows an xy view of a sensor grid 900 when the dial 200 includes conductive elements A, B, D, and E (AB≠BD≠DE≠EA) with pseudo-random distances from each other. As shown in FIG. 9, the reference pattern (sensor matrix around the conductive elements) is expanded from a 3×3 square matrix to an n×n square matrix, resulting in a combination of reference models of single conductive elements distributed at exactly the same positions around the dial center C according to the actual conductive elements. The touch screen controller 120 can perform the correlation coefficient calculations in the same way as in the embodiment with a single conductive element, but the sum in equation (2) is expanded from 3×3 to n×n to reflect the larger size of the reference response model. That is,

number

[0053] The same equations (1) and (8) as in the embodiment with a single conductive element are then used to define the dial angle position and the negative peak position after the initial movement. The use of multiple conductive elements has much better noise immunity than the single conductive element embodiment because more sensor data is used in the correlation coefficient calculation. However, the amount of mathematical calculations required also increases by a factor of M. That is, M=n 2 / 3 2 (11) It becomes.

[0054] In some embodiments, instead of calculating the correlation coefficient of the two parameters at each angle, the touch screen controller 120 can utilize a least squares method to determine the similarity between the difference count response for the conductive element at each angle and the reference response model. min is the resolution angle of the conductive finger simulator, as shown in the following formula: L min =MIN(L j ) when α min =j (12)

number

[0055] In the above formula, L j is the least squared distance of angle j.

[0056] FIG. 10 is an exemplary representation of a touchscreen display (such as touchscreen display 100 of FIG. 1) having a passive dial 200 attached thereto.

[0057] 11 illustrates a system 1000 for calibrating a touchscreen display and a system 1050 for operating it, according to some embodiments of the present disclosure. In the system 1000, during manufacturing, for example, the capacitive response of the touchscreen is measured at each dial angle using dedicated measurement software (e.g., on the computing device 1010). The computing device 1010 can adjust the height and radius of the reference paraboloid to the measured values ​​of the height and radius of the main peak and store these parameters in the memory of the touchscreen controller 120.

[0058] System 1050 illustrates a similar operating environment to that described in FIG. 1B in an embodiment in which determination of the angle of the passive dial is performed by a host CPU in a separate device.

[0059] 12 illustrates one embodiment of a core architecture 1100 of a PSoC® processing device, such as that used in the PSoC3® family of products sold by Cypress Semiconductor Corporation of San Jose, California. In one embodiment, the core architecture 1100 includes a microcontroller 1102. The microcontroller 1102 includes a CPU (central processing unit) core 1104 (which may correspond to the processing device 130 of FIG. 1), flash program storage 1106, a DOC (debug on chip) 1108, a prefetch buffer 1110, a private SRAM (static random access memory) 1112, and special function registers 1114. In one embodiment, the DOC 1108, the prefetch buffer 1110, the private SRAM 1112, and the special function registers 1114 are coupled to the CPU core 1104 (e.g., CPU core 1006), and the flash program storage 1106 is coupled to the prefetch buffer 1110.

[0060] The core architecture 1100 may also include a CHub (Core Hub) 1116, which includes a bridge 1118 and a DMA controller 1120 coupled to the microcontroller 1102 via a bus 1122. The CHub 1116 may provide a primary data and control interface between the microcontroller 1102 and its peripherals (e.g., peripherals) and memory, and the programmable core 1124. The DMA controller 1120 may be programmed to transfer data between system elements without burdening the CPU core 1104. In various embodiments, these subcomponents of the microcontroller 1102 and the CHub 1116 may differ depending on each selection or type of CPU core 1104. The CHub 1116 may also be coupled to a shared SRAM 1126 and a SPC (System Performance Controller) 1128. The private SRAM 1112 is separate from the shared SRAM 1126, which is accessed by the microcontroller 1102 via the bridge 1118. The CPU core 1104 accesses the private SRAM 1112 without going through the bridge 1118, thus allowing access to local registers and RAM simultaneously with DMA access to the shared SRAM 1126. Although referred to here as SRAM, these memory modules may be any suitable type of a wide variety of (volatile or non-volatile) memory or data storage modules in various other embodiments. The core architecture 1100 may also include an analog front end 1138 that performs measurement and digitization of the capacitance value (similar to the capacitance sensing circuit 125 shown in FIGS. 1A and 1B).

[0061] In various embodiments, the programmable core 1124 may include various combinations of subcomponents (not shown), such as, but not limited to, digital logic arrays, digital peripherals, analog processing channels, global routing analog peripherals, DMA controllers, SRAM and other suitable types of data storage, IO ports, and other suitable types of subcomponents. In one embodiment, the programmable core 1124 includes a GPIO (general purpose IO) and EMIF (extended memory interface) block 1130 for providing a mechanism to expand the external off-chip access of the microcontroller 1102, a programmable digital block 1132, a programmable analog block 1134, and a specialized function block 1136, each configured to implement one or more of the subcomponent functions. In various embodiments, the specialized function block 1136 may include a dedicated (non-programmable) function block and / or may include one or more interfaces to a dedicated function block, such as USB, a crystal oscillator drive, JTAG, etc.

[0062] The programmable digital block 1132 may include a digital logic array that includes an array of digital logic blocks and associated routing. In one embodiment, the digital block architecture is configured as a Universal Digital Block (UDB). For example, each UDB may include an ALU in addition to the functionality of a CPLD.

[0063] In various embodiments, one or more of the UDBs of the programmable digital block 1132 can be configured to perform various digital functions, including, but not limited to, one or more of the following functions: basic I2C slave; I2C master; SPI master or slave; multi-wire (e.g., 3-wire) SPI master or slave (e.g., MISO / MOSI multiplexed on a single pin); timers and counters (e.g., a pair of 8-bit timers or counters, one 16-bit timer or counter, one 8-bit capture timer, etc.); PWM (e.g., a pair of 8-bit PWMs, one 16-bit PWM, one 8-bit deadband PWM, etc.); level-sensitive I / O interrupt generator; quadrature encoder; UART (e.g., half-duplex); delay line; and any other suitable type or combination of digital functions that can be implemented in multiple UDBs.

[0064] In other embodiments, a group of two or more UDBs can be used to implement additional functionality. By way of example only and not limitation, multiple UDBs can be used to implement the following functionality: I2C slave supporting hardware address detection, the ability to handle complete transactions without intervention of a CPU core (e.g., CPU core 1104), and features that help prevent forced clock stretching on any bit in the data stream; I2C multi-master, which may include slave options in a single block; any-length PRS or CRC (up to 32 bits); SDIO; SGPIO; digital correlator (e.g., up to 32 bits with 4x oversampling and supporting configurable thresholds); LINbus interface; delta-sigma modulator (e.g., for a class-D audio DAC with differential output pairs); I2S (stereo); LCD drive control (e.g., to implement timing control for the LCD drive block and address the display RAM). a UDB can be used for any of the following: full duplex UART (e.g., 7-bit, 8-bit or 9-bit with 1 or 2 stop bits and parity, RTS / CTS support); IRDA (transmit or receive); capture timer (e.g., 16-bit, etc.); deadband PWM (e.g., 16-bit, etc.); SMbus (including formatting of SMbus packets with CRC in software); brushless motor drive (e.g., supporting 6 / 12 step commutation); automatic BAUD rate detection and generation (e.g., automatically determines BAUD rate for standard rates of 1200 to 115200 BAUD and, after detection, generates the necessary clocks to generate the BAUD rate); and any other suitable type or combination of digital functions that can be implemented in multiple UDBs.

[0065] The programmable analog block 1134 may include analog resources such as, but not limited to, comparators, mixers, PGAs (programmable gain amplifiers), TIAs (transimpedance amplifiers), ADCs (analog-to-digital converters), DACs (digital-to-analog converters), reference power supplies, current sources, sample and hold circuits, and any other suitable type of analog resources. The programmable analog block 1134 may support a variety of analog functions such as, but not limited to, analog routing, LCD drive IO support, capacitive sensing, voltage measurement, motor control, current-to-voltage conversion, voltage-to-frequency conversion, differential amplification, light measurement, inductive position monitoring, filtering, voice coil drive, magnetic card reading, acoustic Doppler measurement, acoustic ranging, modem transmit and receive encoding, or any other suitable type of analog function.

[0066] The embodiments described herein can be used in various designs of mutual capacitance sensing systems, self-capacitance sensing systems, or a combination of both. In one embodiment, a capacitive sensing system can detect multiple sensing elements operating in an array and analyze the signal patterns for adjacent sensing elements to separate noise from the actual signal. The embodiments described herein are not tied to a discrete capacitive sensing solution and can be used with other sensing solutions as well, including optical sensing solutions, as will be appreciated by one of ordinary skill in the art having the benefit of this disclosure.

[0067] Although the above description sets forth numerous details, it will be apparent to one skilled in the art having the benefit of this disclosure that the embodiments of the present disclosure may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the description.

[0068] Some portions of the detailed description are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. Each step requires physical manipulations of physical quantities. Usually, but not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, primarily for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.

[0069] It should be noted that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. As is apparent from the above discussion, unless specifically stated otherwise, discussions utilizing terms such as "determining," "detecting," "comparing," "resetting," "adding," "calculating," and the like throughout this description will be understood to refer to the actions and processes of a computing system or similar electronic computing device that manipulates and converts data represented as physical quantities (electronic quantities) in the registers and memory of the computing system into other data similarly represented as physical quantities in the memory or registers of the computing system or other such information storage, transmission, or display devices.

[0070] The word "example" or "exemplary" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as an "example" or "exemplary" should not necessarily be construed as preferred or advantageous over other aspects or designs. Rather, the use of the word "example" or "exemplary" is intended to present concepts in a specific manner. As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or." That is, unless otherwise specified or clear from the context, "X includes A or B" is intended to mean any of the natural inclusive permutations. That is, "X includes A or B" satisfies any of the cases where X includes A, where X includes B, or where X includes both A and B. In addition, as used in this application and the appended claims, the article "a" or "an" should generally be construed to mean "one or more" unless otherwise specified or clear from the context to mean the singular form. Furthermore, use of the terms "in one embodiment" or "one embodiment" or "an implementation" or "one implementation" throughout is not intended to refer to the same embodiment or implementation, unless so stated.

[0071] The embodiments described herein may also relate to an apparatus for carrying out the operations of the embodiments. This apparatus may be specially constructed for the required purposes or may comprise a general purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a non-transitory computer readable storage medium, such as, for example, but not limited to, a floppy disk, an optical disk, a CD-ROM, any type of disk including a magneto-optical disk, a read-only memory (ROM), a random access memory (RAM), an EPROM, an EEPROM, a magnetic or optical card, a flash memory, or any type of medium suitable for storing electronic instructions. The term "computer readable storage medium" should be understood to include a single medium or multiple media (e.g., a centralized or distributed database and / or associated caches and servers) that store one or more sets of instructions. The term "computer readable medium" should also be understood to include any medium that can store, encode or carry a set of instructions for execution by a machine and cause a machine to perform any one or more of the methodologies of the present embodiments. The term "computer-readable storage medium" should be understood to include, but is not limited to, solid-state memory, optical media, magnetic media, and any medium that can store a set of instructions for execution by a machine and that causes a machine to perform any one or more of the methodologies of the present embodiments.

[0072] The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will appear from the description that follows. In addition, the present embodiments are not described with reference to any particular programming language. It will be understood that a variety of programming languages ​​can be used to implement the teachings of the embodiments as described herein.

[0073] The above description reveals numerous specific details, such as examples of specific systems, components, and methods, to provide a good understanding of some embodiments of the present disclosure. However, it will be apparent to those skilled in the art that at least some embodiments of the present disclosure can be practiced without these specific details. In other instances, well-known components or methods have not been described in detail or have been presented in a simple block diagram format so as not to unnecessarily obscure the present embodiments. Thus, the specific details described above are merely illustrative. Individual implementations may differ from these illustrative details and still be considered to be within the scope of the present embodiments.

[0074] It should be understood that the above description is intended to be illustrative, and not limiting. Many other embodiments will be apparent to those of ordinary skill in the art upon reading and understanding the above description. Accordingly, the scope of the embodiments should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. a touch screen having a plurality of capacitive sensors; a passive dial having one or more conductive elements; a touch screen controller operably coupled to the touch screen; 1. A capacitive touch screen display comprising: the passive dial is at least partially mounted within an active area of ​​the touchscreen such that the one or more conductive elements are proximate to a surface of the touchscreen and move with rotation of the passive dial; The touch screen controller includes: detect a current angle of the passive dial based at least in part on a measured capacitive response of one or more capacitive sensors of the plurality of capacitive sensors to the one or more conductive elements as the passive dial rotates; outputting data corresponding to the current angle of the passive dial to a user interface controller; It is structured as follows: To detect the current angle of the passive dial, the touch screen controller determining a correlation coefficient based on a baseline response of a set of the plurality of capacitance sensors and a measured capacitance response of the set of capacitance sensors for each angle of the passive dial; identifying the angle of the passive dial having the greatest correlation coefficient as the current angle of the passive dial; It is configured as follows: Capacitive touchscreen display.

2. The sets of capacitance sensors for the individual angles form a matrix whose centers are located on the edges of the passive dial at the individual angles.

2. The capacitive touch screen display of claim 1.

3. The reference response of the set of capacitive sensors is modeled as a paraboloid.

3. The capacitive touch screen display of claim 2.

4. The reference response of the set of capacitive sensors is modeled as a Gaussian.

3. The capacitive touch screen display of claim 2.

5. The touch screen controller includes: measuring a raw count value for each of the plurality of capacitive sensors; initializing a baseline response value of each of the plurality of capacitive sensors to a measured raw count value; [0023] 2. The capacitive touch screen display of claim 1.

6. The touch screen controller includes: Identifying the passive dial angle having the smallest correlation coefficient corresponding to a negative parasitic peak; and in response to detecting an initial movement of the passive dial, resetting, for each of the second set of the plurality of capacitance sensors, a baseline response value of the capacitance sensor to a respective current raw count value. wherein the second set of capacitive sensors form a matrix centered on an edge of the passive dial at an angle corresponding to the minimum correlation coefficient.

6. The capacitive touch screen display of claim 5.

7. providing a passive dial mounted within an active area of ​​a touchscreen comprising a plurality of capacitive sensors, the passive dial including one or more conductive elements proximate a surface of the touchscreen and adapted to move with rotation of the passive dial; detecting, with a processing device, a current angle of the passive dial based at least in part on a measured capacitive response of one or more capacitive sensors of the plurality of capacitive sensors to the one or more conductive elements as the passive dial rotates; outputting data corresponding to the current angle of the passive dial to a user interface controller; Including, The step of detecting the current angle of the passive dial includes: determining, for each angle of the passive dial, a degree of similarity between a baseline response of a set of the plurality of capacitive sensors and a measured capacitive response of the set of capacitive sensors; identifying the angle of the passive dial that has the greatest similarity as the current angle of the passive dial; Including, method.

8. The sets of capacitance sensors for the individual angles form a matrix whose centers are located on the edges of the passive dial at the individual angles. The method of claim 7.

9. The method of claim 8, wherein the reference response of the set of capacitive sensors is modeled as a paraboloid. The method of claim 8.

10. The method of claim 1, wherein the reference response of the set of capacitive sensors is modeled as a Gaussian. The method of claim 8.

11. The method comprises: measuring a raw count value for each of the plurality of capacitive sensors; initializing a baseline response value of each of the plurality of capacitive sensors to a measured raw count value; Further comprising: The method of claim 7.

12. The method comprises: identifying an angle of the passive dial having a minimum similarity between a reference response of the set of capacitance sensors and a measured capacitance response of the set of capacitance sensors, the angle corresponding to a negative parasitic peak; responsive to detecting an initial movement of the passive dial, resetting, for each of a second set of the plurality of capacitance sensors, a baseline response value of the capacitance sensor to a respective current raw count value, the second set of capacitance sensors forming a matrix centered on an edge of the passive dial at an angle corresponding to the minimum similarity; Further comprising: The method of claim 11.

13. Memory, a processing device operably coupled to the memory; A touch screen controller comprising: the memory stores a reference response for each angle of a passive dial, the passive dial being at least partially mounted within an active area of ​​a touch screen having a plurality of capacitance sensors, one or more conductive elements of the passive dial being proximate to a surface of the touch screen and moving with rotation of the passive dial, the reference response for each angle corresponding to a set of the plurality of capacitance sensors; The processing device comprises: detect a current angle of the passive dial based at least in part on a reference response for each angle of the passive dial and a measured capacitive response of one or more capacitive sensors of the plurality of capacitive sensors to the one or more conductive elements for each angle of the passive dial; outputting data corresponding to the angle of the passive dial to a user interface controller; It is structured as follows: To detect the current angle of the passive dial, the processing device comprises: determining a similarity between a baseline response of the set of the plurality of capacitive sensors and a measured capacitive response of the set of capacitive sensors for each angle of the passive dial; identifying the angle of the passive dial having the greatest similarity as the current angle of the passive dial; It is configured as follows: Touchscreen controller.

14. The sets of capacitance sensors for the individual angles form a matrix whose centers are located on the edges of the passive dial at the individual angles.

14. The touch screen controller of claim 13.

15. the reference response of the set of capacitive sensors is modeled as a paraboloid; 15. The touch screen controller of claim 14.

16. The touch screen controller includes: measuring a raw count value for each of the plurality of capacitive sensors; initializing a baseline response value of each of the plurality of capacitive sensors to a measured raw count value; [0023] 14. The touch screen controller of claim 13.

17. The touch screen controller includes: identifying an angle of the passive dial having a minimum similarity between a reference response of the set of capacitance sensors and a measured capacitance response of the set of capacitance sensors, the angle corresponding to a negative parasitic peak; and in response to detecting an initial movement of the passive dial, resetting, for each of the second set of the plurality of capacitance sensors, a baseline response value of the capacitance sensor to a respective current raw count value. wherein the second set of capacitive sensors form a matrix centered on an edge of the passive dial at an angle corresponding to the minimum similarity.

17. The touch screen controller of claim 16.

Images