SYSTEM AND METHOD FOR NON-CONTACT INTERACTION WITH MOBILE DEVICES
20180004298 · 2018-01-04
Assignee
Inventors
Cpc classification
G06F3/017
PHYSICS
International classification
Abstract
Disclosed is a system and method for controlling handheld devices without contact by interacting with their wireless charging coils or other inductive coil antennae. The present disclosure utilizes the interaction between human body and the coil wherein the coil is used to send alternating magnetic field to interact with a control signal, such as a hand, instead of simply using the coil in the smart phone as a power receiver. The hand movement in front of the wireless charging coil changes the coil's conductivity distribution, which creates effective coil impedance also known as reflected impedance.
Claims
1. A control circuit suitable for contactless interaction with a mobile device, the circuit configured to control the functionality of a mobile device, the control circuit comprising: a power supply, an oscillator circuit configured to electromagnetically engage a control element, the oscillator circuit comprising: at least one inductive coil, a gain device, and a parallel LC circuit, the at least one inductive coil configured to generate a resonant frequency and to generate an electromagnetic field, the oscillator circuit configured to enable the control element to vary the resonant frequency of the at least one inductive coil without contacting the mobile device, wherein certain functionality within the mobile device can be controlled by varying the resonant frequency of the oscillator circuit.
2. The control circuit of claim 1, wherein the gain device includes a bipolar junction transistor.
3. The control circuit of claim 1, wherein the gain device includes a field effect transistor.
4. The control circuit of claim 1, wherein the gain device includes an operational amplifier.
5. The control circuit of claim 1, wherein at least one inductive coil is additionally configured to operate as a power transfer device to receive power from a power source and provide power to the mobile device to charge the mobile device.
6. The control circuit of claim 1, wherein the parallel LC circuit is included in a feedback loop connected to the gain device such that the output of the gain device is connected to the input of the feedback loop.
7. The control circuit of claim 6, wherein the parallel LC circuit includes at least two capacitors that are disposed in parallel with the inductive coil.
8. The control circuit of claim 6, wherein the parallel LC circuit includes a bandpass filter to set the frequency of oscillation within the inductive coil.
9. The control circuit of claim 1, wherein the control circuit is configured to detect when the control element engages the oscillator circuit to control the mobile device to display at least one of the following, a field to enter a URL for a mobile web site, a calculator, a numerical Roman numeral telephone display, a menu, an icon, an alarm clock, a calendar, a field to enter text information, text messages, text messaging information, a game, a document, global positioning system information, global positioning system functionality, navigation functionality, push to talk functionality, roaming information, roaming functionality, cellular network information, a website, web content, a power management setting, email information, email content, email functionality, a folder, folder content, a note, a reminder, music, digital photographs, videos, locally stored information, and software application content.
10. The control circuit of claim 7, wherein the parallel LC circuit further includes a variable capacitor that is connected in parallel to the inductive coil and configured to tune the oscillator circuit.
11. The control circuit of claim 10, wherein the control circuit is further configured to detect a time interval wherein the control element engages the oscillator circuit.
12. The control circuit of claim 11, wherein the control circuit is further configured to use the detected time interval to control the mobile device.
13. The control circuit of claim 1, wherein the mobile device is one of a computer, a notebook computer, a laptop computer, a personal data assistant (PDA), a mobile telephone, a smart phone, an electronic book reader, a radio, an MP3 player, and a portable music player.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing and other objects, features, and advantages of the disclosure will be apparent from the following description of embodiments as illustrated in the accompanying drawings, in which reference characters refer to the same parts throughout the various views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating principles of the disclosure:
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[0019]
DETAILED DESCRIPTION OF THE DISCLOSURE
[0020] While the making and using of various embodiments of the present disclosure are discussed in detail below, it should be appreciated that the present disclosure provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the disclosure and do not delimit the scope of the disclosure.
[0021] All publications and patent applications mentioned in the specification are indicative of the level of skill of those skilled in the art to which this disclosure pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
[0022] The present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, specific example embodiments. Subject matter may, however, be embodied in a variety of different forms and, therefore, covered or claimed subject matter is intended to be construed as not being limited to any example embodiments set forth herein; example embodiments are provided merely to be illustrative. Likewise, a reasonably broad scope for claimed or covered subject matter is intended. Among other things, for example, subject matter may be embodied as methods, devices, components, or systems. Accordingly, embodiments may, for example, take the form of hardware, software, firmware or any combination thereof (other than software per se). The following detailed description is, therefore, not intended to be taken in a limiting sense.
[0023] Throughout the specification and claims, terms may have nuanced meanings suggested or implied in context beyond an explicitly stated meaning. Likewise, the phrase “in one embodiment” as used herein does not necessarily refer to the same embodiment and the phrase “in another embodiment” as used herein does not necessarily refer to a different embodiment. It is intended, for example, that claimed subject matter include combinations of example embodiments in whole or in part.
[0024] In general, terminology may be understood at least in part from usage in context. For example, terms, such as “and”, “or”, or “and/or,” as used herein may include a variety of meanings that may depend at least in part upon the context in which such terms are used. Typically, “or” if used to associate a list, such as A, B or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B or C, here used in the exclusive sense. In addition, the term “one or more” as used herein, depending at least in part upon context, may be used to describe any feature, structure, or characteristic in a singular sense or may be used to describe combinations of features, structures or characteristics in a plural sense. Similarly, terms, such as “a,” “an,” or “the,” again, may be understood to convey a singular usage or to convey a plural usage, depending at least in part upon context. In addition, the term “based on” may be understood as not necessarily intended to convey an exclusive set of factors and may, instead, allow for existence of additional factors not necessarily expressly described, again, depending at least in part on context.
[0025] The present disclosure is described below with reference to block diagrams, formulas, and operational illustrations of methods and devices. It is understood that each block of the block diagrams or operational illustrations, and combinations of blocks in the block diagrams or operational illustrations, can be implemented by means of analog or digital hardware and computer program instructions. The present disclosure provides systems and methods for operating a mobile device, such as a smart phone, without physically touching the device. For example, hand movement in front of an inductive coil interrupts the electromagnetic near-field introduced by the coil, which results in the impedance change of the coil. This enables us for non-contact interaction with the coil by impedance measurements, which can be modeled with a transformer model, as shown in
[0026] The non-contact interaction can be described with using transformer equations. The coil is modeled as inductor L.sub.1 with resistor R.sub.1 in series considering the resistance of the coil itself, while the human hand is modeled as L.sub.2 and R.sub.2 in parallel. When the human hand is brought into electromagnetic field generated by the inductance coil, the coil and the hand are electromagnetically coupled via the mutual inductance M.sub.12=M.sub.21. This interrelationship can be described by two equations in the frequency domain:
U.sub.1=R.sub.1I.sub.1+jwL.sub.1I.sub.1−jwM.sub.12I.sub.2 (1)
U.sub.2=jwL.sub.2I.sub.2−jwM.sub.12I.sub.1 (2)
[0027] In (2) U.sub.2 is zero considering that a control element, such as a the hand, has high resistance. Solving (2) for I.sub.2 and inserting the result into (1) gives the input impedance of the first mesh, which is the reflected impedance of the inductive coil Z.sub.ind,r due to electromagnetic coupling with the hand:
Z.sub.ind,=R.sub.1+jwL.sub.1+w.sub.2M.sup.2.sub.12/jwL.sub.2 (3)
[0028] Separating equation (3) into the real and imaginary parts provides information on the effective resistance and reactance of the reflected coil impedance, which will directly affect the resonant frequency of the oscillator circuit, which consists of the inductive coil and a capacitor. One embodiment of an oscillator circuit whose frequency is determined by the coil impedance Z.sub.ind is shown in
where L.sub.ind,0 is the inductance and R.sub.ind,0 is the resistance of the empty coil. The frequencies of the coil fosc with and without any object in front of the coil acting as a damping resistance can be calculated with (4) by R.sub.ind=R.sub.ind,0 and R.sub.ind=.sub.Rind,0+ΔR.sub.ind, respectively. As discussed, changes in conductivity distribution in front of the inductive coil due to control element movement will affect the impedance of the coil and will eventually change the resonant frequency of the oscillator circuit.
[0029] One embodiment of an oscillator circuit utilized in the control circuit and mobile device control system is depicted in
[0030]
[0031] Experiments were performed by setting the oscillator circuit upright on a table, with an oscilloscope connected to the oscillator output to measure the real-time circuit response while a control signal, in the form of a hand, was waving in front of the wireless charging coil. As discussed in herein, the impedance change directly affects the resonant frequency of the circuit.
[0032] Turning to
[0033] In a series of experiments utilizing one embodiment of the present invention, the subject person waved her hands once, twice and three times in front of the coil without touching it. The whole waveform was recorded during this 0.8 second period using the oscilloscope with a sampling rate of 50 MHz. Then short-time FFT was applied to analyze the data recorded. These signals including the measurements of impedance, charge, voltage, current, or other suitable electrical signal information at the oscillator circuits may be utilized to control the functionality of a mobile device.
[0034] As is illustrated in
[0035]
[0036] Where the oscillatory sensor device 800 utilizes multiple oscillatory circuits 804, sensor device 800 may include an array of inductive coils that may each form a resonant frequency node. When a control element is used to interact with the mobile device, a change in the resonant frequency of the inductive coil may occur at the resonant frequency node and the controller 610 may determine the position of the control element, the strength of the resonant frequency, the change in the resonant frequency and the duration of the resonant frequency at each of the frequency nodes. Additionally, one or more sense lines 802 may run horizontally across the oscillatory sensor device 800 to intersect the vertical sense lines 802 shown in
[0037] In an alternative embodiment, the vertical oscillator sensing lines 802 and the horizontal oscillator sensing lines 802 (not shown) may come near each other but not make electrical contact with one another. In another embodiment of the present invention, a pulsed or alternating voltage may be applied to each of the oscillator circuits. As in the other embodiments of the present invention, a change in the resonant frequency of each of the resonant inductive coils due to the interaction of a control element with the oscillatory sensor device 800 may be measured along with other parameters by the controller to control one or more functionalities of the mobile device. By measuring changes in the resonant frequency throughout the array of one or more oscillator circuits, controller 610 may determine the position of the mobile control element, the duration of interaction between the one or more oscillator circuits and the one or more control elements and, in combination with host processor 700 shown in
[0038] In particular embodiments of the present invention, one or more oscillator circuits may together form a resonant sense line 802 running horizontally or vertically or in any suitable configuration. Similarly, one resonant sense line 802 running horizontally and one resonant sense line 802 running vertically may intersect or come nearest each other to form a resonant inductive node. The change in resonant frequency across one or more oscillator circuits 804 as a result of interaction with a control element may be measured at the inductive coils that are included in the oscillator circuits 804, at one or more resonant frequency nodes, or any combination of the two. Moreover, this disclosure contemplates any suitable method to detect a change in the resonant frequency of an inductive coil.
[0039] After detecting a change in resonant frequency, controller 610 may then communicate information about the resonant frequency to one or more components (such one or more central processing units (CPUs)) of a device that includes oscillator sensor circuit device 800 and controller 610, which may respond to the resonant frequency input by initiating a function of the mobile device or a software application running on the mobile device, or help in initiating or performing some function of the mobile device. Although this disclosure describes a particular controller having particular functionality with respect to a mobile device and a particular oscillator circuit 804, this disclosure contemplates any suitable controller that has the ability to determine the types of measurements necessary to initiate a function of a mobile device or a software application running on the mobile device, or help to initiate or perform one or more functions of the mobile device.
[0040] Controller 610 may be one or more integrated circuits (ICs), general-purpose microprocessors, microcontrollers, programmable logic devices (PLDs) or programmable logic arrays (PLAs), or application-specific ICs (ASICs). In particular embodiments, controller 610 comprises analog circuitry, digital logic, and digital non-volatile memory. In particular embodiments, controller 610 is disposed on a flexible printed circuit (FPC) bonded to the substrate of oscillatory sensor device 800. The FPC may be active or passive, where appropriate. In particular embodiments multiple controllers 610 are disposed on the FPC. In accordance with one embodiment as depicted in
[0041] The oscillator I/O circuitry may supply drive signals to the oscillator sensors of oscillatory sensor device 800. Drive signals may take any suitable waveform or be of any suitable frequency, number, or duration, in particular embodiments. Drive signals may be periodic signals driven at a suitable frequency. The oscillator I/O circuitry may sense resonant frequency, impedance, charge, voltage, current, or another other suitable electrical signal information at the oscillator circuits 804 and/or the resonant frequency nodes of oscillatory sensor device 800 and provide measurement signals to the processor unit representing the change in resonant frequency at the inductive coils. Controller 610 can simultaneously resolve and track multiple resonant frequency fluctuations that occur due to the mobile device control element interacting with the electromagnetic field generated by the inductive coils included in the oscillator circuits. The aforementioned fluctuations that are measured by the controller 610 to control the functionality of the mobile device occur without requiring the mobile device control element to come into contact with the mobile device or the oscillatory sensor device 800. A high refresh rate allows the controller 610 to track rapid fluctuations within the resonant frequency of the one or more oscillator circuits and interactions between a mobile device control element due to movements of the same through the electromagnetic field(s) generated by the oscillator circuits and any additional movements without appreciable delay. The embedded processor filters the data, identifies the resonant frequency fluctuation coordinates and reports them to the host. The embedded firmware can be updated via patch loading. Processing may be performed on the sensed signals to determine any suitable characteristic of the signals, such as resonant frequency of the one or more signals, spectral frequencies of the one or more signals, signal amplitude, and changes in the aforementioned signal characteristics. The processor unit may also control the drive signals to the oscillator circuits disposed within the oscillatory sensor device 800 by the oscillator I/O circuitry and process measurement signals transmitted from the oscillator I/O circuitry to detect and process the presence, duration, and location of a change in the resonant frequency due to the interaction of a mobile control element with the mobile device via one or more electromagnetic-sensitive areas of oscillatory sensor device 800. The processor unit may also track changes in the position of the mobile control element or resonant input within the electromagnetic-sensitive areas of oscillatory sensor device 800 and the duration of the time intervals in which these oscillator circuits are impacted. The storage unit may store programming for execution by the processor unit, including programming for controlling the oscillator I/O circuitry to supply drive signals to the oscillator circuits disposed within the oscillatory sensor device 800, programming for processing measurement signals from the oscillator I/O circuitry, and other suitable programming to enable the controller to communicate the necessary information to the mobile device host processor to interact with and control the mobile device functionality.
[0042] The mobile device that may be controlled by the one or more embodiments of the present invention include a computer, a notebook computer, a laptop computer, a personal data assistant (PDA), a mobile telephone, a smart phone, an electronic book reader, a radio, an MP3 player, and a portable music player, or any other suitable mobile device known by those having skill in the art and have a display. The mobile device may have a display and an oscillatory sensor device 800 with a electromagnetically sensitive areas due to the one or more oscillator circuits disposed within the oscillatory sensor device 800. The mobile device display may be a liquid crystal display (LCD), a LED display, a LED-backlight LCD, plasma display, or other suitable display.
[0043] The functionality of a mobile device, for example a feature or smartphone, may be controlled using the mobile device control signals transmitted from the controller 610 to the mobile host processor. In turn, the mobile device electronics provide the functionality of mobile device, including the mobile device functionality that may be controlled due to the interaction of the mobile device control element with the oscillatory sensor device 800 disposed adjacent to the mobile device display and in another suitable location upon or within the mobile device. For example, a mobile device may include electronics and other circuitry to enable the mobile device to communicate wirelessly to or from the device to display information to a user, execute programming on the device, generate graphical or other user interfaces (UIs) for the device, manage power functions and enter into and out of different states of power consumption, take and/or transmit pictures, record audio/visual information, or any suitable combination of these and other functionalities well-known in the art. Additionally, a mobile device may be controlled by the aforementioned embodiments of the present invention to display a field to enter a URL for a mobile web site, a calculator, a numerical Roman numeral telephone display, a menu, an icon, an alarm clock, a calendar, a field to enter text information, text messages, text messaging information, a game, a document, global positioning system information, global positioning system functionality, navigation functionality, push to talk functionality, roaming information, roaming functionality, cellular network information, a website, web content, a power management setting, email information, email content, email functionality, a folder, folder content, a note, a reminder, music, digital photographs, videos, locally stored information, and software application content, or any other information known to be displayed by a mobile device by a person having ordinary skill in the art.
[0044]
[0045] The zoom-in view of the fundamental frequency variation clearly demonstrates the effect that hand movement on the coil's resonant frequency. Taking
[0046] According to the exemplary embodiments, the present disclosure utilizes the above approach to utilize inductive coils of mobile devices as a wireless sensor for non-contact hand interaction based on standard smart phone WPT/NFC coils. An oscillator circuit is built using the inductive coil as part of the resonant circuit to send electromagnetic field to interact with human hand. Hand movement without touching anything will affect the impedance of the coil, which will result in variation of the oscillator resonant frequency.
[0047] In another embodiment, smaller inductive coils and respective oscillator circuits may be utilized to control the functionality of a mobile device. Indeed, any configuration of X by X or Y by Y arrays of uniformly spaced or non-uniformly spaced oscillator circuits may be utilized by the present invention. For example, if the control circuit of the present invention receives oscillator sensor circuitry signals for a swipe wherein the sensor includes a plurality of oscillator circuits formed in a 2×2, 4×4, 16×16, etc. array, this means that the resonant frequency of multiple oscillator circuits have been impacted due to the non-contact interaction between a mobile device control element and the induction coils of the oscillator circuits such that they are measurable. In this instance, measurements of electrical characteristics, such as the resonant frequency, may be taken across inductance coils electromagnetically engaged and adjacent coils to figure out the type of gesture that was performed. These measurements may include a comparison of measurements across multiple oscillator circuits to determine direction of swipe, duration of swipe, and the change in resonance frequency. Alternatively, the speed of the swipe may also be calculated if the host processor requires that information within the control signals sent by controller to control the functionality of the mobile device. One or more oscillator circuits may be disposed anywhere within or adjacent to any surface of the mobile device, not just adjacent to the display screen, to control mobile device functionality.
[0048] In other embodiments, the variation of the oscillation frequency is shown, hence making noncontact interaction between human and smart phones possible. A standard smart phone WPT/NFC coil is measured 2.8 cm×3.2 cm, which is much smaller than a mobile device. It is thus possible to embed a 2×2 coil array inside a mobile device, such as a smart phone. With this arrangement, the smart phone can detect relative distance of the hand, more gesture patterns, and the direction of hand movements in a plane parallel with the phone.
[0049] Those skilled in the art will recognize that the methods and systems of the present disclosure may be implemented in many manners and as such are not to be limited by the foregoing exemplary embodiments and examples. In other words, functional elements being performed by single or multiple components, in various combinations of hardware and software or firmware, and individual functions, may be distributed among software applications at either the client level or server level or both. In this regard, any number of the features of the different embodiments described herein may be combined into single or multiple embodiments, and alternate embodiments having fewer than, or more than, all of the features described herein are possible.
[0050] Functionality may also be, in whole or in part, distributed among multiple components, in manners now known or to become known. Thus, myriad software/hardware/firmware combinations are possible in achieving the functions, features, interfaces and preferences described herein. Moreover, the scope of the present disclosure covers conventionally known manners for carrying out the described features and functions and interfaces, as well as those variations and modifications that may be made to the hardware or software or firmware components described herein as would be understood by those skilled in the art now and hereafter.
[0051] Furthermore, the embodiments of methods presented and described as flowcharts in this disclosure are provided by way of example in order to provide a more complete understanding of the technology. The disclosed methods are not limited to the operations and logical flow presented herein. Alternative embodiments are contemplated in which the order of the various operations is altered and in which sub-operations described as being part of a larger operation are performed independently.
[0052] While various embodiments have been described for purposes of this disclosure, such embodiments should not be deemed to limit the teaching of this disclosure to those embodiments. Various changes and modifications may be made to the elements and operations described above to obtain a result that remains within the scope of the systems and processes described in this disclosure.