Abstract
The invention concerns a robust user interface for electronic devices where a single measurement circuit is used to measured inductance values due to user press events through sealable surface, as well as capacitance values due to user proximity and/or touch events, and with both the measured inductance and capacitance values used to determine user input commands.
Claims
1.-16. (canceled)
17. An electronic device comprising a measurement circuit, an inductive structure, a first electrically isolated conductive member and a second conductive member, wherein said measurement circuit is used to measure an inductance of said structure due to a user press event, said press event causing the first conductive member to move towards said structure, wherein said measurement circuit is further used to measure a capacitance of said second conductive member due to user proximity and/or touch events, and wherein the electronic device uses the measured capacitance and inductance to discern user input commands.
18. The electronic device of claim 17, wherein the measurement circuit also measures a capacitance of said first conductive member due to user proximity and/or touch events, and wherein the electronic device uses the measured capacitance and inductance to discern user input commands.
19. The electronic device of claim 17, wherein said first conductive member is an electrically isolated snap dome structure.
20. The electronic device of claim 17, wherein additional conductive or magnetic material is located near said inductive structure to provide a constant reference for inductance measurements.
21. The electronic device of claim 18, wherein a third conductive member is used as a conductive insert that is isolated from said user, and which transmits capacitive coupling from the user to the first conductive member.
22. The electronic device of claim 17, further comprising a magnetic member, and wherein the user press event causes said magnetic member to move closer to the inductive structure subsequent to the first conductive member moving closer to the inductive structure.
23. The electronic device of claim 22, wherein inductance measurements by the measurement circuit provides an indication when said magnetic member moves closer to the inductive structure, and wherein the electronic device utilizes said indication for discerning of user input commands.
24. The electronic device of claim 17, further comprising an additional plurality of conductive members, and wherein capacitance measurements with the measurement circuit for the second and said additional plurality of conductive members are used to form a swipe or slider interface.
25. The electronic device of claim 17, wherein said measurement circuit comprise charge transfer circuitry.
26. A method for controlling an electronic device comprising a measurement circuit, an inductive structure, a first electrically isolated conductive member and a second conductive member, wherein the method comprises the step of the measurement circuit measuring an inductance of said structure due to a user press event, said press event causing the first conductive member to move towards said structure, the step of the measurement circuit measuring a capacitance of said second conductive member due to user proximity and/or touch events, and the step of said electronic device using the measured capacitance and inductance to discern user input commands.
27. The method of claim 26, further including the step of the measurement circuit measuring a capacitance of the first conductive member, and the step of said electronic device using the measured capacitance and inductance to discern user input commands.
28. The method of claim 26, wherein said first conductive member is an electrically isolated snap dome structure.
29. The method of claim 26, wherein additional conductive or magnetic material is located near the inductive structure to provide a constant reference for inductance measurements.
30. The method of claim 27, wherein a third conductive member is used as a conductive insert that is isolated from said user, and which transmits capacitive coupling from the user to the first conductive member.
31. The method of claim 26, further comprising a magnetic member, and wherein the user press event causes said magnetic member to move closer to the inductive structure subsequent to the first conductive member moving closer to the inductive structure.
32. The method of claim 31, further including the step of the measurement circuit providing an indication when said magnetic member moves closer to said inductive structure, as well as the step of the electronic device utilizing said indication for discerning of user input commands.
33. The method of claim 26, further comprising an additional plurality of conductive members, and wherein capacitance measurements with the measurement circuit for the second and said additional plurality of conductive members are used to form a swipe or slider interface.
34. The method of claim 26, wherein said measurement circuit comprise charge transfer circuitry and wherein said measurement steps are performed with the charge transfer circuitry.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] The invention is further described by way of examples with references to the accompanying drawings in which:
[0050] FIG. 1A shows an exemplary Rocker Switch utilizing two such coil-plate pairs.
[0051] FIG. 1B shows a modification to the Rocker Switch include a coil-ferrite pair and create a tri-state switch.
[0052] FIG. 2A shows a momentary push-switch which may be waterproof.
[0053] FIG. 2B shows a modification to the deformation mechanism so as to enable additional capacitive sensing.
[0054] FIG. 3 shows a biased push button.
[0055] FIG. 4 shows a push button implementation using ferrite and metal rod.
[0056] FIG. 5 shows a coil configuration which reduces the capacitive effects during sensing.
[0057] FIG. 6A-6C shows an exemplary embodiment in the form of the stem of a TWS earphone.
[0058] FIG. 7 shows an exemplary embodiment in the form of a conductive member which amplifies or reduces the distance caused by user interaction.
[0059] FIG. 8 shows an exemplary embodiment in the form of a section of an electronic device enclosure using conductive structures for multiple parameter measurements and functionalities.
[0060] To further clarify the disclosure of the present invention, the following descriptions relating to the appended drawings are presented. These should not be construed as limiting to the claims of the invention and are merely used to support clarity of disclosure. A large number of alternative embodiments may be possible that still fall within the spirit and scope of the present invention, as may be recognised by one skilled in the relevant arts.
[0061] In the first embodiment, as drawn in FIG. 1A, inductive coil structures 1.7 on a PCB 1.3a with sense IC 1.4 may be inside a housing 1.2. Aligned above the inductive coil structures 1.7 may be flexible conductive plates 1.6—the deformation of these plates may change the nature of the current flowing in the inductive coil structure, which may be detected by the sense IC 1.4, in this way interactions (e.g. presses) may be detected.
[0062] Further, the embodiment may utilize two such coil-plate pairs 1.6 & 1.7, and a see-saw rocker structure 1.1a which may rotate about a centre 1.5a such that only one coil-plate pair may be momentarily depressed at a time.
[0063] Given the nature of ferrite to increase the mutual inductive coupling, as opposed to conductive metals which generally reduces the mutual inductive coupling, in the rocker switch embodiment using two sensors: one of the sensors may be metal and the other ferrite. The rocker action may then create a differential signal that may have greater signal to noise ratio and increased immunity to temperature effects.
[0064] In a modification to the first embodiment, shown in FIG. 1B, the PCB 1.3b may include a third additional inductive coil 1.7, below a ferrite plate 1.9 mounted on a spring 1.8. The ferrite-coil pair may be aligned directly below the rocking centre 1.5b of the modified button rocker 1.1b. The rocking centre 1.5b may be modified such that it may also translate such that pushing down on the middle of the button 1.1b may translate the rocking centre 1.5b such that the spring 1.8 compresses and the ferrite plate 1.9 may move towards the coil 1.7. Because of the ferrite plate 1.9 the signal may be easily differentiated from that of the conductive plates 1.6. Temperature effects may be accounted for as the signals in the two conductive plates 1.6 should change in the same direction, this may be differentiated from a centre push because of the way the ferrite plate 1.9 should affect the coil 1.7 associated with it.
[0065] In the second embodiment, as drawn in FIG. 2A, the flexible conductive plate 2.1 may be held in place by a lower support 2.9 and upper support 2.6. The push button 2.7 may push down on the flexible conductive plate 2.1 through the button post 2.8. The button post's movement may be limited by the upper support 2.6 and the flexible conductive plate 2.1. The whole push button and flexible conductive plate with support structures 2.6, 2.7, 2.8, 2.9, 2.1 may be removed from the housing 2.5. The presence of conductive material may be detected, and the interaction (e.g. deforming the material relative to the sensing coil) may also be detected. The push-button mechanism's support structures 2.6, 2.7, 2.8, 2.9, 2.1 are merely part of the example hardware and not integral or limiting to the invention and serve merely to illustrate one of many ways in which a waterproof switch may be implemented.
[0066] While inductive sensing overcomes some of the environmental drawbacks of capacitive sensing, for a given application, it may be beneficial to have an inductive switch that includes capacitive sensing. For example, proximity detection may be used to illuminate the switch so that the user knows where to press. To this end, a modification to the push button which deforms the conductive plate is show in FIG. 2B, here a conductive insert 2.10 may be secured inside the switch elements. The conductive insert 2.10 may still be electrically isolated from the user and from the sense-circuit 2.2, 2.3, 2.4, but may be electrically connected to the flexible conductive plate 2.1. In this way, capacitive coupling from the user to the conductive insert 2.10 may be transmitted to the flexible conductive plate 2.1 where it may be sensed from an additional capacitive sensing electrode or the coil 2.2 being used a capacitive sensing electrode with sensor or sensor IC 2.3.
[0067] In this way, capacitive proximity detection may be used, for example, to wake the sensors from a low-power sleep state when the user is close enough to begin activating the inductive switch.
[0068] To augment the spring-type action a latching mechanism could be implemented, creating for example a traditional ON-OFF switch which when pressed latches and remains in the position until released by a subsequent press.
[0069] In FIG. 3, a conductive plate 3.3 is placed below a coil 3.4 on a PCB 3.5. This may bias the signal detected by sensor or sensing IC 3.6. Above the coil 3.4 on a spring 3.2 may be a plate of ferrite 3.1. Depressing the ferrite plate 3.1 towards the coil 3.4 may increase the mutual inductive coupling, which may already be biased by the conductive plate 3.3 below the coil 3.4 on the underside of the PCB 3.5. In this method, a constant reference may always be established on the sensor 3.6. This may make the system immune to the presence of conductive materials in the working environment, e.g. placing the device comprising the inductive switch on a metal surface. It is also noted that the roles of the ferrite plate and the conductive plate may be reversed, such that the ferrite plate is always biasing the coil.
[0070] Again, using the difference between ferrite and metal, an example of a push button switch utilizing a rod mechanism is illustrated in FIG. 4 where in a plunger 4.1 may be connected to a rod made of one or more alternating conductive sections 4.5a & 4.5b and ferrite element 4.6. With the assistance of a spring 4.2 or similar mechanism, the rod may be translated through a hole 4.7 in the PCB 4.3 away from a rest position by pressing the plunger 4.1 and compressing the spring 4.2. The hole 4.7 may be located in the middle of one or more inductive sensing coils 4.8a & 4.8b, the passage of the ferrite 4.6 or conductive 4.5 elements through the coils 4.8 should change the nature of the signal sensed by the sensor or sensing IC 4.4. Having an element always in place while in the rest position means that there should always be a defined reference signal for the system to use. And, by implementing more than one coil, the system may use differential signals to remove environmental effects (e.g. temperature, etc.).
[0071] FIG. 5 illustrates an inductive coil which is between an input signal (TX) 5.1 and sensing port (RX) 5.2. Typically, when conductive material or ferrite is brought closer, the mutual inductance between the material and the coil may change the nature of the current flowing in the coil, and this may be sensed. However, when the coil's windings become numerous and tight, the capacitive coupling between the windings of the coil may become significant enough that capacitive interaction with the coil (e.g. human finger) may influence the capacitive coupling sufficiently so as to create a detectable change in the current. To reduce this, additional traces (shown in dashed-lines) may be included between the traces of the inductive coil. These are connected to Ground 5.3, but do not form a closed path for current to flow, and as a result only capacitive coupling may be formed to ground. This capacitive coupling may be significantly stronger, and as a result any additional capacitive interaction with the coil (e.g. human finger) should not be strong enough to influence the coil.
[0072] FIG. 6A shows a part of an electronic device which embodies the present invention, for example a stem 6.2 of a TWS earphone or earbud at 6.1. The stem enclosure may typically contain an inner enclosure such as that shown by 6.3, which may be used for sealing or to contain and locate electronics within the earphone. A user may interface with the electronic device via a push button 6.4. Inductive sensing circuitry may be used to monitor push button 6.4. To better describe the embodiment of FIG. 6A, stem enclosure 6.2 and inner enclosure 6.3 are drawn as transparent objects at 6.5 and a cross-sectional view along AA′ is provided at 6.12 in FIG. 6B. As shown, a substrate, such as a printed circuit board, 6.6 may be located within inner enclosure 6.3, with a coil structure 6.11 located on the substrate. For example, coil structure 6.11 may be fashioned out of etched copper tracks, as is known in the art. A circuit 6.7 may be used to measure the inductance of coil 6.11, for example using charge transfer techniques and circuitry. Push button 6.4 may be fashioned out of pliant material such as rubber or the one or other elastomer. A conductive member 6.13 may be placed on the bottom face of push-button 6.4. When a user presses onto the push button, it may deflect causing conductive member 6.13 to come closer to coil 6.11, which may cause a measurable change in the inductance of said coil. For example, such a change may be used to discern a user press event on the stem of a TWS earphone. Naturally, as would be perceived by those skilled in the art, the present invention is not limited to the use of a conductive member for 6.13, as it may also be a magnetic member, for example a ferrite member. In addition, the present invention is not limited to the push button structure depicted but may use any of the aforementioned structures described by this disclosure, or others. For example, it may use metallic snap domes, which is well known in the art. The push button structure may also be located within the outer enclosure 6.2 or inner enclosure 6.3 and may be pressed by the user through said enclosures, without departing from the teachings or scope of the present invention.
[0073] Also evident from the depictions at 6.5 and 6.12 are half-circle or round members 6.8, 6.9 and 6.10, located on the bottom side of substrate 6.6. These may be conductive members which may be connected, either directly or via an isolation barrier, to circuit 6.7 which may measure the capacitance (self-capacitance or mutual-capacitance) for each member or for combinations of the members. Said capacitance measurements may be used by circuit 6.7 or another circuit to discern user proximity and touch events. For example, conductive members 6.8, 6.9 and 6.10 may be used to form a slider or swipe structure, wherein a user input via touch or proximity may only be declared or annunciated if a specific sequence of changes in the capacitance measured for said members is detected, as is known in the art of capacitive sensing.
[0074] According to the present invention, an embodiment as depicted in FIGS. 6A, 6B and 6C may be used to provide an intuitive and robust user interface for an electronic device such as a TWS earphone. For example, a specific user command may require a specific sequence of a user press action or actions on push button 6.4 and touches or proximity events on conductive members 6.8, 6.9 and 6.10, or on material covering them, before said command will be declared or annunciated. Such an interface may advantageously also offer more options for commands than that held by the art due to a larger number of input parameters.
[0075] Said conductive members may also be used to seat or locate substrate 6.6 within the inner enclosure 6.3. Cross-sectional view along BB′ shown at 6.14 illustrates this aspect, where conductive member 6.9 can be seen to fit snugly against the inner wall of enclosure 6.3. As mentioned before during the current disclosure, conductive members such as 6.8, 6.9 and 6.10 may also be used for other functions, for example as antennas to send or receive radio communication signals. For example, they may be use as radio frequency antennas for communication with BLE® or other well-known wireless technologies and standards.
[0076] It is to be appreciated that the use of inner and outer enclosures in FIG. 6A to 6C is merely exemplary and should not be construed as a limit of the present invention. For example, and single enclosure may be used by the electronic device in lieu of an outer and inner enclosure, with said push button structure located on the outside of the single enclosure and electronic parts such as members 6.6 to 6.11, and others, located inside the enclosure. The enclosure may therefore be sealed against the ingress of liquids, solids and gasses, for example is may be sealed against the ingress of water or sweat.
[0077] In addition, in the above embodiment, members 6.13 may also be replaced by a metallic snap dome structure, the latter being ubiquitous and well known in the art. In such an exemplary embodiment, member 6.4, or another member not shown, may press down on said snap dome when a user applies pressure to member 6.4. With sufficient pressure this may cause the snap dome to snap through, providing tactile feedback to the user and causing the metal of the snap dome to move measurably closer to coil 6.11.
[0078] FIG. 7 shows two exemplary embodiments of the present invention at 7.1 and 7.8. A substrate 7.2, for example a printed circuit board, may have a conductive structure 7.4 located on it. A circuit (not shown) may measure the one or other parameter of structure 7.4 such as its inductance (self-inductance or mutual-inductance), capacitance (self-capacitance or mutual-capacitance), resistance, temperature and so forth. For example, structure 7.4 may be a coil or inductive structure of which the inductance is measured. A member 7.5 or 7.10 may be located above member 7.4 and may be fashioned out of e.g. conductive material. When a user, or other entity, causes 7.5 or 7.10 to move closer to 7.4, a change in inductance may be measured, similar to that described earlier during the current disclosure. According to the present invention, structures such as at 7.1 and 7.8 may be used to amplify the change in distance caused by a user. When a user presses on member 7.3, anchored to substrate 7.2 at 7.7, member 7.3 may deflect a first distance. However, due to the length of member 7.5 and the manner in which it is attached to 7.3, for example with fastener 7.6, the corresponding change in distance at d of member 7.5 over structure 7.4 may be much greater than said first distance. It may also be possible to decrease the corresponding change in distance at d relative to said first distance by choosing the length and position of member 7.5 correctly.
[0079] The embodiment shown at 7.8 is similar, except that a single conductive member 7.10, anchored at 7.9 to substrate 7.2, is used, wherein 7.10 is fashioned as shown, negating a need for fasteners and multiple members.
[0080] Capacitance measurements to discern user, or other, input may also be performed for conductive or magnetic members located over coil structures, according to the present invention. That is, a conductive or magnetic member may be pressed by a user, directly or indirectly, to cause it to move closer to or further from a coil, causing a measurable change in coil inductance, while capacitance, or another parameter, of said conductive or magnetic member may also be measured to provide additional information on user intent or other aspects. This is illustrated in exemplary manner by the embodiment shown at 8.1 in FIG. 8, where a section of the enclosure for an electronic device is shown. For example, the electronic device may a TWS earphone and the section shown may form part of the stem of said earphone. Said enclosure may have an outer surface 8.2 and inner surface 8.3, with a flexible and conductive member 8.5 located underneath an area 8.4 of the enclosure, said area being earmarked for user press inputs. A substrate 8.6, for example a printed circuit board, may be located in the enclosure, with flexible and conductive member 8.5 anchored to substrate 8.6. An inductive structure 8.8, for example a coil structure, may be present on the surface of the substrate facing said conductive member. A circuit (not shown) may measure the inductance (self-inductance or mutual-inductance) of coil 8.8. When a user presses down on area 8.4 it may deflect and cause flexible and conductive member 8.5 to move closer to coil 8.8, resulting in a measurable change in its inductance, akin to that described before. The same circuit (not shown) used to measure the inductance of coil 8.8, or another circuit (not shown), may be used to measure the capacitance (self-capacitance or mutual-capacitance) of flexible and conductive member 8.5. These capacitance measurements may be used to discern user proximity and touch events, for example.
[0081] In addition, another conductive structure 8.7 may be located on the opposite side of substrate 8.6 as shown. This conductive structure may be used to locate and seat the substrate within enclosure 8.2. It may also be used for capacitance measurements (self-capacitance mutual-capacitance) by the same circuit (not shown) used for said inductance measurements, or by another circuit (not shown). These capacitance measurements may be used in addition to, or separate from, the capacitance measurements for 8.5 to discern user proximity and touch events. In the preceding, the inductance and capacitance measurements may be performed with charge transfer circuitry and may be used in any combination to discern user input commands and intent.
[0082] Further, conductive members 8.5 and 8.7 may be a single unitary piece without departing from the current invention. That is, a single conductive member may be used for capacitance measurements to detect touch and proximity events on opposite sides of substrate 8.6 and to facilitate a user press action that influences the measured inductance of coil 8.8 by coming closer or moving further from said coil. Members 8.5 and 8.7, or said single member, may also be fashioned out of a magnetic material without departing from the present invention, with the requirement that said magnetic material has sufficient conductivity to allow the capacitance measurements.
[0083] Similar to that described earlier for FIG. 6A to 6C, conductive members 8.5 and 8.7 may also be used as radio frequency antennas to facilitate radio communication of signals to transmit voice or data. It may also be possible, according to the present invention, to use said conductive members as the antennas for distinct radio frequencies. In other words, as an example, member 8.5 may be used to communicate on one frequency and member 8.7 may be used to communicate on another frequency.
