CN112187244A - Switch operation sensing apparatus and detection apparatus - Google Patents

Abstract

The present disclosure provides a switching operation sensing apparatus including an input operation unit, an oscillation circuit, a frequency-to-digital converter, and a touch detection circuit. The input operation unit includes a first switch member integrally formed with a housing. The oscillation circuit is configured to generate an oscillation signal whose resonance frequency changes during an input operation based on a change in capacitance or a change in inductance according to a touch input member in contact with the first switch member. The frequency-to-digital converter is configured to convert the oscillation signal into a count value. The touch detection circuit is configured to detect capacitive sensing and inductive sensing based on a slope change of the count value received from the frequency-to-digital converter, and to output corresponding different levels of touch detection signals based on the detection.

Description

Switch operation sensing apparatus and detection apparatus

This application claims the benefit of priority of korean patent application No. 10-2019-0080120, filed in the korean intellectual property office at 7/3/2019, and korean patent application No. 10-2019-0132912, filed in the korean intellectual property office at 10/24/2019, the entire disclosures of which are incorporated herein by reference for all purposes.

Technical Field

The present disclosure relates to a switch operation sensing apparatus with touch input member recognition.

Background

In general, it is desirable for wearable devices to be thin and have a simple, clean design. To achieve this, existing mechanical switches in wearable devices have been replaced with non-mechanical switches implemented with dust and water resistant technologies, thus developing a seamless model.

Current technologies such as metal touch (ToM) technology that touches a metal surface, capacitive sensing methods using a touch panel, Micro Electro Mechanical Systems (MEMS), micro strain gauges, and other technologies have been developed. In addition, even force-touch functionality that can determine the strength with which a button is pressed is under development.

In the case of existing mechanical switches, for example, a relatively large size and internal space are required to implement the switching function (which may have a somewhat untidy design and may require a large amount of space due to the convex shape of the switch), and the structure of the switch may not be integrated into the housing.

Furthermore, there is a risk of electric shock due to direct contact with the electrically connected mechanical switch. In addition, the structure of the mechanical switch makes it difficult to prevent dust and water.

Disclosure of Invention

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

In one general aspect, a switch operation sensing apparatus includes an input operation unit, an oscillation circuit, a frequency-to-digital converter, and a touch detection circuit. The input operation unit includes a first switch member integrally formed with a housing. The oscillation circuit is configured to generate an oscillation signal whose resonance frequency changes during an input operation based on a change in capacitance or a change in inductance according to a touch input member in contact with the first switch member. The frequency-to-digital converter is configured to convert the oscillation signal into a count value. The touch detection circuit is configured to: capacitive sensing and inductive sensing are detected based on a slope change of the count value received from the frequency-to-digital converter, and corresponding different levels of touch detection signals are output based on the detection.

The frequency-to-digital converter may be further configured to generate the count value by counting a reference clock signal using the oscillation signal.

The first switch member and the housing may be formed using the same material.

The input operation unit may further include a second switch member integrated with the housing and disposed at a position different from that of the first switch member, and the second switch member and the housing may be formed using the same material.

The oscillating circuit may include an inductive circuit and a capacitive circuit. The inductive circuit may comprise a first coil element arranged on an inner side of the first switching means. The capacitive circuit may include a capacitive element connected to the inductive circuit. The oscillating signal may have a first frequency characteristic when the first switching member is touched by a human body part, and may have a second frequency characteristic when the first switching member is touched by a non-human body input member.

The oscillating circuit may include an inductive circuit and a capacitive circuit. The inductive circuit may include a first coil element disposed on an inner side of the first switch member and having an inductance that varies when the first switch member is touched by a non-human body input element. The capacitive circuit may include a capacitive element connected to the inductive circuit and have a capacitance that changes when the first switching member is touched by a human body part.

The first coil element may be mounted on a substrate and attached to an inside surface of the first switch member.

The frequency-to-digital converter may be further configured to: a divided reference clock signal is generated by dividing a reference frequency signal by a reference dividing ratio, and the count value generated by counting the divided reference clock signal by the oscillation signal is output.

The frequency-to-digital converter may be further configured to: the method includes generating a divided reference clock signal by dividing a reference frequency signal using a reference division ratio, dividing the oscillation signal from the oscillation circuit using a sensing division ratio, and outputting the count value generated by counting the divided reference clock signal using the divided oscillation signal.

The frequency-to-digital converter may include a down-converter, a period timer, and a cascaded integrator-comb (CIC) filter circuit. The down-converter may be configured to: a reference frequency signal is received as a reference clock signal and a divided reference clock signal is generated by dividing the reference clock signal using a reference divide ratio to down-convert the frequency of the reference frequency signal. The cycle timer may be configured to: the oscillation signal is received as a sampling clock signal, and a cycle count value generated by counting the divided reference clock signal of one cycle time received from the down-converter using the sampling clock signal is output. The cascaded integrator-comb (CIC) filter circuit may be configured to output the count value generated by performing cumulative amplification on the period count value received from the period timer.

The CIC filter circuit can include a decimator CIC filter configured to: performing an accumulation amplification of the period count value from the period timer using a predetermined number of integration stages, a predetermined decimator factor, and a predetermined comb differential delay order; and providing a cycle count value of the accumulated amplification.

The touch detection circuit may differentiate the count value received from the frequency digitizer to generate a difference value, and compare the difference value with each of a predetermined falling threshold value and a predetermined rising threshold value to output the touch detection signal having one of different levels for identifying capacitive sensing and inductive sensing based on a comparison result.

The touch detection circuit may include a delay circuit, a subtraction circuit, and a slope detection circuit. The delay circuit may be configured to: delaying the count value received from the frequency-to-digital converter by a time determined based on a delay control signal to output a delayed count value. The subtraction circuit may be configured to: subtracting the count value from the delay count value to generate and output a difference value. The slope detection circuit may be configured to: comparing the difference value received from the subtraction circuit with each of a predetermined falling threshold value and a predetermined rising threshold value to output the touch detection signal having the first level or the second level for identifying capacitance sensing and inductance sensing based on a comparison result.

The slope detection circuit may include a slope detector, a falling slope detector, a rising slope detector, and a detection signal generator. The slope detector may be configured to: determining whether the difference decreases or increases, and outputting an enable signal in an active state when the difference decreases, and outputting an enable signal in an inactive state when the difference increases. The falling slope detector may be configured to: generating a fall detection signal when the enable signal enters the active state and the difference is less than or equal to a fall threshold for a predetermined time. The rising slope detector may be configured to: generating a rise detection signal when the enable signal enters the active state and the difference is greater than or equal to a rise threshold for the predetermined time. The detection signal generator may be configured to: generating the touch detection signal having a first level or a second level based on the falling detection signal and the rising detection signal.

When the difference increases after falling, the detection signal generator may generate the touch detection signal having a first level based on the falling detection signal and the rising detection signal in response to capacitance sensing.

When the difference value decreases after rising, the detection signal generator may generate the touch detection signal having a second level based on the falling detection signal and the rising detection signal in response to inductance sensing.

The electronic device may be any one of a bluetooth headset, a bluetooth ear bud headphone, smart glasses, a VR (virtual reality) headset, an AR (augmented reality) headset, a fob button of a vehicle, a laptop computer, a Head Mounted Display (HMD), and a stylus.

In another general aspect, a detection apparatus includes: the touch panel includes a housing, an input operation unit, an oscillation circuit, and a touch detection circuit. The input operation unit includes a first switch member integrally formed with the housing. The oscillation circuit is configured to generate an oscillation signal based on a contact to a touch input member on the first switch member. The touch detection circuit is configured to: one of capacitance sensing and inductance sensing is determined based on a slope change of a count value of the oscillation signal, and a detection signal is output based on the determined sensing.

The oscillation circuit may be further configured to: generating the oscillation signal having a resonance frequency corresponding to the touch input member contacting the first switch member during an input operation.

The detection device may further include a frequency-to-digital converter connected to the oscillation circuit and configured to convert the oscillation signal to the count value.

The input operation unit may further include a second switch member formed integrally with the housing and disposed at a position different from that of the first switch member.

When the contact of the touch input member is a human touch, the contact may be determined to be the capacitive sensing, and when the contact of the touch input member is a non-human input member touch, the contact may be determined to be the inductive sensing.

Other features and aspects will be apparent from the following detailed description, the accompanying drawings, and the claims.

Drawings

Fig. 1A and 1B are diagrams of an example of a mobile device according to the present application.

Fig. 2 is a sectional view taken along line I-I' in fig. 1A showing an example of the structure of the touch input sensing apparatus in fig. 1A.

Fig. 3 is a sectional view taken along line I-I' in fig. 1B showing an example of the structure of the touch input sensing apparatus in fig. 1B.

Fig. 4 is a block diagram of an example of an oscillating circuit and circuit components of a switch operation sensing device according to the present application.

Fig. 5 is an example of a circuit diagram of the oscillation circuit when not touched.

Fig. 6 shows an example of a capacitive sensing method when touched by a human body part.

Fig. 7 is an example of a circuit diagram of an oscillation circuit when touched by a human body part.

Fig. 8 is a detailed circuit diagram of the oscillation circuit in fig. 7.

Fig. 9 shows an example of an inductance sensing method when touched by a non-human input member.

Fig. 10 is an example of a circuit diagram showing an example of an oscillation circuit when touched by a non-human body input member.

Fig. 11 is a block diagram showing an example of a frequency-to-digital converter.

FIG. 12 illustrates an example operation of the cycle timer.

Fig. 13 is a block diagram showing an example of the touch detection circuit.

Fig. 14 is a block diagram showing an example of the slope detection circuit in fig. 13.

Fig. 15 shows an example of the count value and the difference value (slope value of the count value) when touched by a human body part.

Fig. 16 shows an example of the count value and the difference value when touched by the non-human body input member.

Fig. 17 shows an example of a drift of the count value and the difference value when touched by a human body part.

Fig. 18 shows examples of the difference value change, the falling threshold value, the rising threshold value, and the touch detection signal.

Fig. 19 shows examples of various applications of the switch operation sensing device of the present application.

Like reference numerals refer to like elements throughout the drawings and the detailed description. The figures may not be drawn to scale and the relative sizes, proportions and depictions of the elements in the figures may be exaggerated for clarity, illustration and convenience.

Detailed Description

The following detailed description is provided to assist the reader in obtaining a thorough understanding of the methods, devices, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and/or systems described herein will be apparent after understanding the disclosure of the present application. For example, the order of operations described herein is merely an example, and is not limited to the order of operations set forth herein, but rather, in addition to operations that must occur in a particular order, changes may be made to the order of operations described herein that will be apparent upon an understanding of the disclosure of the present application. In addition, descriptions of features known in the art may be omitted for the sake of clarity and conciseness.

The features described herein may be embodied in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many possible ways to implement the methods, devices, and/or systems described herein that will be apparent after understanding the disclosure of the present application.

Throughout the specification, when an element such as a layer, region or substrate is described as being "on," "connected to" or "coupled to" another element, it may be directly on, "connected to" or "coupled to" the other element or one or more other elements may be present therebetween. In contrast, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element, there may be no intervening elements present.

As used herein, the term "and/or" includes any one of the associated listed items and any combination of any two or more.

Although terms such as "first", "second", and "third" may be used herein to describe various elements, components, regions, layers or sections, these elements, components, regions, layers or sections should not be limited by these terms. Rather, these terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section referred to in the examples described herein could also be referred to as a second element, component, region, layer or section without departing from the teachings of the examples.

The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the disclosure. The singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," and "having" specify the presence of stated features, quantities, operations, elements, components, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and/or combinations thereof.

As will be apparent after understanding the disclosure of the present application, the features of the examples described herein may be combined in various ways. Moreover, while the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

Fig. 1A and 1B are external views of an example of a mobile device according to the present application.

In fig. 1A, the mobile device 10 includes a touch panel 11, a case 500, and an input operation unit SWP. The input operation unit SWP may include a first switch member SM1 instead of the mechanical button switch. In fig. 1B, the mobile device 10 includes a touch panel 11, a case 500, and an input operation unit SWP. The input operation unit SWP may include a first switch member SM1 and a second switch member SM2 instead of the mechanical button switch. Here, it should be noted that the use of the term "may" with respect to an example or embodiment (e.g., with respect to what the example or embodiment may include or implement) indicates that there is at least one example or embodiment that includes or implements such a feature, and all examples and embodiments are not limited thereto.

In fig. 1B, the input operation unit SWP is shown to include a first switch member (or first touch member) SM1 and a second switch member (or second touch member) SM 2. However, this is only an example for easy description, and the input operation unit SWP is not limited to the two switch members SM1 and SM2, and it will be understood that the number of touch members may be expanded in the same manner as the first and second touch members.

By way of example, in fig. 1A and 1B, the mobile device 10 may be a portable device (such as a smartphone) or a wearable device (such as a smartwatch), but is not limited to any particular device. The mobile device 10 may be a portable electronic device or a wearable electronic device, or any electronic device having a switch for operating a control.

The case 500 may be a housing for an electronic device. For example, when the switch operation sensing apparatus is applied to a mobile device, the case 500 may be a cover provided on a side portion (side surface) of the mobile device 10. As an example, the case 500 may be integrated with a cover provided on a rear surface of the mobile device 10, or may be separated from a cover provided on a rear surface of the mobile device 10.

As described above, the housing 500 may be a housing of an electronic device, but is not limited to any particular location, shape, or configuration.

In fig. 1B, each of the first and second switching members SM1 and SM2 may be disposed inside the case 500 of the mobile device 10, but the disposition thereof is not limited thereto.

The first and second switching members SM1 and SM2 may be provided on a cover of the mobile device 10. In this case, the cover may be a cover that does not include a touch screen, for example, a side cover, a rear cover, or a cover that may be provided on a portion of the front surface. For convenience of description, a case provided on a side cover of a mobile device will be described as an example, but the case is not limited thereto.

Fig. 2 is a sectional view taken along line I-I' in fig. 1A showing an example of the structure of the touch input sensing apparatus in fig. 1A.

In fig. 2, the switch operation sensing apparatus includes an input operation unit SWP, an oscillation circuit 600, a frequency-to-digital converter 700, and a touch detection circuit 800.

The input operation unit SWP may include at least one first switch member SM1 integrated with the case 500 of the electronic device. As an example, the first switching member SM1 may comprise the same material as the housing 500.

The oscillation circuit 600 may generate an oscillation signal LCosc whose resonant frequency varies based on a capacitance variation or an inductance variation according to the touch input member during an input operation through the first switching member SMl. For example, the oscillating circuit 600 includes an inductive circuit 610 and a capacitive circuit 620. In examples described in the present application, the touch input member (or the object of the input operation) may include a human body part (such as a human hand) and a non-human body input member (such as plastic). In the examples described in the present application, the input operation may be a concept including a touch input or a force input.

The frequency to digital converter 700 may convert the oscillation signal from the oscillation circuit 600 into a count value. For example, the frequency digitizer 700 may convert the oscillation signal LCosc into the count value L _ CNT in a frequency counting manner.

The touch detection circuit 800 may be configured to recognize and Detect capacitance sensing by a human body part and inductance sensing by a non-human body input member based on the count value L _ CNT input from the frequency digitizer 700, and may output a touch detection signal (DF) Detect _ Flag having different levels from each other based on the detection.

A first example of the input operation unit SWP will be described with reference to a front view of the housing in the direction a in fig. 2.

As an example, the input operation unit SWP may include the first switch member SM1, and the first switch member SM1 may be integrated with the case 500. Accordingly, the first switching member SM1 may be formed using the same material as that of the case 500.

As an example, when the housing 500 comprises a conductor, such as a metal, the first switching member SM1 may also comprise a conductor. On the other hand, when the case 500 includes an insulator such as plastic, the first switching member SM1 may also include an insulator.

For a front view of the first coil element in the direction a in fig. 2, the inductive circuit 610 may be disposed on an inner side of the first switching member SM1 and may have the first coil element 611, the first coil element 611 having the inductance Lind.

Capacitive circuit 620 may include a capacitive element 621 having a capacitance Cext connected to inductive circuit 610. For example, the capacitance of the capacitance circuit 620 may include a touch capacitance Ctouch generated when the input operation unit SWP is touched, and as shown in fig. 7 and 8, the touch capacitance Ctouch (see fig. 7) may be generated, thereby increasing the total capacitance of the oscillation circuit 600.

As an example, the first coil element 611 may include a first coil pattern 611-P having a spiral shape connected between a first land PA1 and a second land PA2 provided on the PCB substrate 611-S.

In fig. 2, the first coil element 611 may be disposed on one surface (e.g., an upper surface) of the substrate 200, and the circuit member CS and the capacitive element 621, such as a multilayer ceramic capacitor (MLCC) or the like, may be disposed on the other surface (e.g., a lower surface) of the substrate 200.

As an example, the circuit member CS may be an Integrated Circuit (IC) including a part of the oscillation circuit 600, the frequency-to-digital converter 700, and the touch detection circuit 800.

The substrate 200 may be a Printed Circuit Board (PCB) or a Flexible Printed Circuit Board (FPCB), but is not limited thereto. The substrate 200 may be a board (e.g., one of various circuit boards such as a PCB) or a panel (e.g., a panel for a Panel Level Package (PLP)) on which a circuit pattern is formed.

The structure of the switch operation sensing apparatus shown in fig. 2 is merely an example, and is not limited thereto.

A non-limiting example of the first switching member SM1 has been described in fig. 2, but the description of the first switching member SM1 is also applicable to the second switching member SM2 (see fig. 1B). For example, when the first and second switching members SM1 and SM2 are included, the single circuit member CS may process different resonance signals corresponding to the first and second switching members SM1 and SM2, respectively.

When describing the drawings of the present application, repetitive description may be omitted for components having the same reference numerals and the same functions, and only differences will be described.

Examples of the switch operation sensing apparatus described below may include a plurality of touch members. In an example, a plurality of touch members may be arranged in a row. Alternatively, the plurality of touch members may be arranged horizontally and vertically in a matrix arrangement.

The example of the switch operation sensing device 50 shown in fig. 1A and 1B may include one or more switch members. However, for convenience of description, the one or more switching members shown in fig. 1A and 1B are only non-limiting examples, and the touch member of the switching operation sensing apparatus is not limited thereto.

Accordingly, it will be understood that the switch-operation sensing device may comprise one or more touch members.

In the examples described in this application, the switch member may be integrated into the housing 500 or integrally formed in the housing 500. The term "integrated" refers to the fact that: regardless of whether the material of the touch member and the material of the case 500 are the same as or different from each other, the touch member and the case 500 are manufactured as one body such that they cannot be easily separated from each other after their manufacture and have an integrated structure (rather than a mechanically separated structure or a physically separated structure) with no discernible gap between the touch member and the case 500.

As an example, the first coil element 611 may be a Printed Circuit Board (PCB) coil element formed in a PCB pattern, but is not limited thereto.

As an example, the first coil element 611 may be a PCB coil element implemented on a double-sided PCB or a multi-layer PCB, but is not limited thereto.

As an example, the first coil element 611 may be formed in various shapes (such as a circle, a triangle, a rectangle, etc.), and the shape of the first coil element 611 is not limited thereto.

Unnecessary repetitive description thereof may be omitted as far as components having the same reference numerals and the same functions in the embodiments of the respective drawings are concerned, and differences between the embodiments of the respective drawings may be described.

Fig. 3 is a sectional view taken along line I-I' in fig. 1B showing another example of the structure of the switch operation sensing apparatus in fig. 1B.

In fig. 3, the switch operation sensing apparatus includes an input operation unit SWP including a first switch member SM1 and a second switch member SM 2.

Each of the first and second switching members SM1 and SM2 may be integrated with the same material of the housing 500 or formed integrally with the same material of the housing 500.

The inductive circuit 610 (see fig. 2) of the tank circuit 600 (see fig. 2) may comprise a first coil element 611 and a second coil element 612. The oscillation circuit 600 (see fig. 2) may include a capacitive element 621. The first coil element 611, the second coil element 612, the capacitance element 621, and the circuit member CS may be mounted on the substrate 200.

The first coil element 611 may be disposed on an inner side of the first switching member SM 1. The second coil element 612 may be disposed on an inner side of the second switching member SM 2.

The switch operation sensing apparatus of the present application may include a plurality of switch members. In this example, in order to generate different oscillation signals based on a touch to each of the plurality of switching members, the switching operation sensing apparatus may include a plurality of coil elements respectively corresponding to the plurality of switching members.

As an example, the first and second switching members SMl and SM2 may be formed using the same material as that of the case 500. When the housing 500 comprises a conductor, such as a metal, the first switch member SMl and the second switch member SM2 may also comprise a conductor. When the housing 500 includes an insulator such as plastic, the first and second switching members SM1 and SM2 may also include an insulator.

Further, the first and second coil elements 611 and 612 may be disposed on one side surface (e.g., an upper surface) of the substrate 200. In a non-limiting example, the circuit member CS and the capacitive element 621, such as an MLCC or other type of capacitor, may be disposed on the other side surface (e.g., the lower surface) of the substrate 200. Such an arrangement structure is merely an example, and is not limited thereto.

The first coil element 611 and the second coil element 612 are spaced apart from each other on one surface of the substrate 200, and are connected to a circuit pattern formed on the substrate 200. For example, each of the first coil element 611 and the second coil element 612 may be a separate coil element (such as a solenoid coil, a wound inductor, a chip inductor, or other type of separate coil element). However, each of the first coil element 611 and the second coil element 612 is not limited thereto, and may be any element having inductance.

As an example, when the first and second switching members SM1 and SM2 are formed using a conductive metal having a high resistance (e.g., 100K Ω or more), interference between the first and second switching members SM1 and SM2 may be reduced, and thus the first and second switching members SM1 and SM2 may be practically applied to an electronic device.

In the examples described in the present application, the term "operation" refers to a touch, a force, or both of the touch and the force input through the input operation unit.

Fig. 4 is a block diagram of an example of an oscillating circuit and circuit components of a switch operation sensing device according to the present application.

In fig. 4, a switch operation sensing apparatus according to the present application may include an oscillation circuit 600, a frequency-to-digital converter 700, and a touch detection circuit 800. As described above, the tank circuit 600 may include the inductive circuit 610 and the capacitive circuit 620.

In the example of the present application, the oscillation circuit 600 may be, for example, an LC oscillation circuit, but is not limited thereto. The oscillation circuit may be configured to generate the oscillation signal using a capacitance variation according to a touch of a human body part or an inductance variation according to a touch of a non-human body input member.

The circuit means CS may include a part of the oscillation circuit 600, the frequency-to-digital converter 700, and the touch detection circuit 800. In this example, a portion of the oscillation circuit 600 may be an amplifier circuit 630. As an example, the amplifier circuit 630 may include an inverter or an amplifier element, and is not limited thereto as long as the amplifier circuit 630 can hold the resonance signal as the oscillation signal.

The circuit member CS may include a capacitive element. When the capacitive element is not included in the circuit component CS, the switch operation sensing device may include a capacitive element 621 (such as an MLCC provided independently of the circuit component CS). In each example of the present application, the circuit member CS may or may not be an Integrated Circuit (IC).

The frequency digitizer 700 may divide the reference frequency signal fref (see fig. 11) by the reference frequency division ratio N to generate the divided reference clock signal DOSC _ ref (see fig. 11), and may count the divided reference clock signal DOSC _ ref (see fig. 11) using the oscillation signal to output the count value L _ CNT.

The touch detection circuit 800 may differentiate the count value L _ CNT received from the frequency digitizer 700 to generate a difference value Diff (see fig. 13). The touch detection circuit 800 may compare the difference value Diff (see fig. 13) with predetermined thresholds F _ TH and R _ TH (see fig. 13) to output a touch detection signal DF (Detect _ Flag) having a level for identifying a human touch or a non-human touch based on the comparison result.

In the examples described in this application, the difference value Diff may correspond to a slope change value of the resonance frequency, a slope change value of the count value, or a difference value.

In the example described in the present application, the count value L _ CNT is a digital value generated by a count processing operation using digital signal processing (not analog signal processing). Therefore, the count value L _ CNT may not be generated by signal amplification performed by a simple analog amplifier, but may be generated according to a counting process operation performed by the frequency-to-digital converter 700 of the present application. Such a counting process operation requires a reference clock signal (e.g., a reference frequency signal) and a sampling clock signal (e.g., an oscillation signal), which will be described later.

In fig. 2 and 4, for example, as described above, the oscillation circuit 600 may include the inductance circuit 610 and the capacitance circuit 620.

The inductive circuit 610 may comprise a first coil element 611 arranged inside a first switching member SMl, and the capacitive circuit 620 may comprise a capacitive element 621 connected to the inductive circuit 610.

As an example, when the first switching member SM1 is touched by a human body part, the oscillation circuit 600 may generate the oscillation signal LCosc having the first frequency characteristic. When the first switching member SM1 is touched by the non-human body input member, the oscillation circuit 600 may generate the oscillation signal LCosc having the second frequency characteristic.

As an example, the inductive circuit 610 may have an inductance that varies when the first switching member SM1 is touched by the non-human body input member, and the capacitive circuit 620 may have a capacitance that varies when touched by a human body part.

As an example, the first coil element 611 may be mounted on the substrate 200 and may be attached to an inner side surface of the first switch member SMl.

Fig. 5 is an example of a circuit diagram of the oscillation circuit when not touched.

In fig. 5, as described above, the oscillation circuit 600 may include the inductance circuit 610, the capacitance circuit 620, and the amplifier circuit 630. The amplifier circuit 630 may include at least one inverter INT or at least one amplifier element. The oscillation circuit 600 can hold the oscillation signal due to the amplifier circuit 630.

The inductive circuit 610 may have an inductance, Lind, of the first coil element 611 when not touched by the non-human input member. When not touched by a human body part, the capacitance circuit 620 may have a capacitance Cext (2Cext and 2Cext) of a capacitance element 621, such as an MLCC.

In fig. 5, the oscillation circuit 600 may be a parallel oscillation circuit including an inductance circuit 610 having an inductance Lind of the first coil element 611 and a capacitance circuit 620 having capacitances Cext (2Cext and 2 Cext).

As an example, the first resonance frequency fres1 of the oscillation circuit 600 when not touched by the human body part or the non-human body input member may be represented by equation 1 below.

fres1≒1/2πsqrt(Lind×Cext)(1)

In formula 1, approximately equal or similar means, and the term "similar" means that other values may be included.

In an example, a resistor may be connected between the first coil element 611 and the capacitive element 621. The resistor may perform an electrostatic discharge (ESD) function.

As disclosed herein, when the touch input member is in contact with the surface of the first switching member SM1 (integrated with the case 500 of the mobile device or integrally formed with the case 500 of the mobile device), the capacitive sensing method may be applied in case of being touched by a human body part, and the inductive sensing method may be applied in case of being touched by a non-human body input member. Thus, a distinction can be established as to whether the input member is a human body part or a non-human body input member.

Fig. 6 shows an example of a capacitive sensing method when touched by a human body part. Fig. 7 is a circuit diagram of an example of an oscillation circuit when touched by a human body part.

In fig. 6 and 7, the capacitance circuit 620 of the oscillation circuit 600 may further have a touch capacitance Ctouch formed due to the touch of the human body part when touched by the human body part. Thus, the total capacitance may vary.

For example, when a human body part (hand) touches the contact surface of the first switching member SM1, the capacitance sensing principle is applied to increase the total capacitance value. As a result, the resonance frequency of the oscillation circuit 600 is reduced (equation 1).

On the other hand, in fig. 9 and 10, when a non-human body input member such as a conductor (metal) touches the contact surface of the first switching member SM1, the inductance sensing principle is applied to reduce the inductance caused by the eddy current. As a result, the resonance frequency is increased.

As described above, in the case of the touch sensing switch structure in which the two sensing methods are mixed, the touch of the human body part and the touch of the non-human body input member can be distinguished from each other according to the rising or falling of the resonance frequency of the oscillation signal.

Fig. 8 shows a detailed example of the oscillation circuit in fig. 7.

In fig. 7 and 8, the oscillation circuit 600 may have a capacitance Cext (2Cext and 2Cext) from a capacitance element 621 included in a capacitance circuit 620 and a capacitance Ctouch (Ccase, Cfinger, and Cgnd) formed when touched by a human body part.

In fig. 8, the touch capacitances Ctouch (Ccase, Cfinger, and Cgnd) may be a case capacitance Ccase and a finger capacitance Cfinger connected in series with each other and a ground capacitance Cgnd between the circuit ground and the ground.

Therefore, it will be understood that the total capacitance of the oscillation circuit 600 in fig. 8 is variable as compared to the oscillation circuit 600 in fig. 5.

For example, when the capacitances 2Cext and 2Cext are expressed as equivalent circuits divided into one capacitance 2Cext and another capacitance 2Cext based on the circuit ground, the case capacitance Ccase, the finger capacitance Cfinger, and the ground capacitance Cgnd may be connected in parallel to the one capacitance 2Cext and the another capacitance 2 Cext.

As an example, the second resonance frequency fres2 of the oscillation circuit 600 may be represented by equation 2 below when touched by a human body part.

fres2≒1/{2πsqrt(Lind×[2Cext‖(2Cext+CT)])}

CT≒Ccase‖Cfinger‖Cgnd(2)

In equation 2, approximately equals or is similar, and the term "similar" means that other values may be included. In equation 2, Ccase represents a parasitic capacitance existing between the case (cover) and the first coil element 611, Cfinger represents a capacitance of a human body part, and Cgnd represents a ground return capacitance between the circuit ground and the ground.

In equation 2, "|" is defined as follows: "a | b" is defined as a series connection between "a" and "b" in the circuit, and the sum value thereof is calculated as "(a × b)/(a + b)".

When equation 1 (when not touched) and equation 2 (when touched by a human body part) are compared, the capacitance 2Cext of equation 1 increases to the capacitance (2Cext + CT) of equation 2. Thus, it will be appreciated that the first resonant frequency fres1 when not touched is reduced to the second resonant frequency fres2 when touched.

In fig. 7 and 8, the oscillation circuit 600 may generate an oscillation signal (having the first resonance frequency fres1 when not touched by the human body part or the second resonance frequency fres2 when touched by the human body part) and may output the oscillation signal to the frequency-to-digital converter 700.

Fig. 9 shows an example of an inductance sensing method when touched by a non-human body input member, and fig. 10 is a circuit diagram showing an example of an oscillation circuit when touched by a non-human body input member.

In fig. 9 and 10, when a non-human body input member such as a conductor (metal) touches the contact surface of the first switching member SM1, the inductance sensing principle is applied, and thus, the inductance caused by eddy current can be reduced to increase the resonance frequency. As described above, the touch of the non-human body input member may be detected based on the increase of the resonance frequency.

In fig. 10, when a touch of a non-human body input member such as metal is input to the first switching member SM1, the inductance is reduced (i.e., Lind- Δ L) due to a change in magnetic force between the first switching member SM1 and the first coil element 611, and thus, the resonance frequency may be increased to detect the touch of the non-human body input member.

The inductive sensing principle will be described below.

When the oscillating circuit is operated, an AC current is generated in the inductor, and a magnetic Field H-Field is generated due to the AC current. In this case, when the metal is touched, the magnetic Field H-Field of the inductor affects the metal to generate a circulating current, e.g., an eddy current. The eddy currents generate a reverse magnetic Field H-Field. The inductance of the existing inductor decreases when the tank circuit is operated in a direction in which the magnetic Field H-Field of the inductor decreases. As a result, the resonance frequency (sensing frequency) increases.

Further, a change in C (capacitance) or L (inductance) is determined according to whether the switching member of the housing is touched by a human body part (hand) or a conductor (metal), which allows determination of a decrease or an increase in frequency.

As described above, two types of sensing may be performed using the structure of a single touch sensing device, and a touch of a human body part and a touch of a non-human body input member may be detected and distinguished from each other and recognized, which will be described below.

Fig. 11 is a block diagram showing an example of a frequency-to-digital converter.

In fig. 11, the frequency digitizer 700 converts the oscillation signal LCosc into a count value L _ CNT. As an example, the frequency to digital converter 700 may count a reference frequency signal (reference clock signal) for a reference time (e.g., one cycle) using the oscillation signal LCosc. Alternatively, the frequency to digital converter 700 may count the oscillation signal LCosc for a reference time (e.g., one cycle) using a reference frequency signal (reference clock signal). The frequency digitizer 700 may be configured to perform a CAL _ hold function by enabling or disabling operation of the frequency digitizer 700. For example, when CAL _ hold is 0, the frequency digitizer 700 operates and updates the count value L _ CNT, and when CAL _ hold is 1, the frequency digitizer 700 stops operating and stops updating the count value L _ CNT.

For example, as shown in equation 3 below, the frequency digitizer 700 may divide the reference frequency signal fref using the reference division ratio N to generate the divided reference clock signal DOSC _ ref ═ fref/N, and may divide the oscillation signal LCosc from the oscillation circuit 600 using the sensing division ratio M. The frequency digitizer 700 may count the frequency-divided reference clock signal DOSC _ ref using the frequency-divided oscillation signal LCosc/M to output the generated count value L _ CNT.

In contrast, the frequency digitizer 700 may count the divided reference signal using the divided sensing signal.

L_CNT＝(N×LCosc)/(M×fref) (3)

In equation 3, LCosc denotes a frequency (resonance frequency) of the oscillation signal, fref denotes a reference frequency, N denotes a frequency division ratio of the reference frequency (for example, 32KHz), and M denotes a frequency division ratio of the resonance frequency.

As shown in equation 2, "dividing the resonant frequency LCosc by the reference frequency fref" means counting the period of the reference frequency fref using the resonant frequency LCosc. When the count value L _ CNT is obtained in the above manner, the low reference frequency fref can be used, and the counting accuracy can be improved.

In fig. 11, a frequency-to-digital converter (FDC)700 may include a down-converter 710, a period timer 720, and a cascaded integrator-comb (CIC) filter circuit 730.

The down converter 710 receives the reference clock signal CLK _ ref (a reference for the time period of the timer to be counted) to down-convert the frequency of the reference clock signal CLK _ ref.

As an example, the reference clock signal CLK _ ref input to the down converter 710 may be any one of the oscillation signal LCosc and the reference frequency signal fref. As an example, when the reference clock signal CLK _ ref is the oscillation signal LCosc input from the oscillation circuit, the frequency of the sensing frequency signal LCosc is down-converted to "DOSC _ ref ═ LCosc/M", where M may be set by an external entity in advance. As another example, when the reference clock signal CLK _ ref is the reference clock signal fref, the reference clock signal CLK _ ref is down-converted to "DOSC _ ref ═ fref/N", where N can be preset by an external entity.

The period timer 720 may count one period time of the divided reference clock signal DOSC ref received from the down-converter 710 using the sampling clock signal CLK _ Spl to generate and output a period count value PCV.

As an example, CIC filter circuit 730 may include a decimator CIC filter. The decimator CIC filter may perform cumulative amplification on the received cycle count value PCV to generate and output a count value L _ CNT.

As another example, CIC filter circuit 730 may also include a first order CIC filter. The first order CIC filter can compute a moving average to remove noise from the output value of the decimator CIC filter.

As an example, the decimator CIC filter may perform cumulative amplification on the period count value from the period timer using a cumulative gain determined based on the period count value from the period timer using a predetermined number of integration steps, a predetermined decimator factor, and a predetermined comb differential delay order, and may provide a cumulative amplified period count value.

For example, when the decimator CIC filter includes an integrating circuit, a decimator, and a differentiating circuit, the cumulative gain can be obtained as [ (R × M) ^ S ] based on the number of stages S of the integrating circuit, a decimator factor R, and a delay order M of the differentiating circuit. For example, when the number of stages S of the integration circuit is 4, the decimator factor R is 1, and the delay order M of the differential circuit is 4, the cumulative gain may be 256, i.e., [ (1 × 4) ^4 ].

Fig. 12 shows the operation of the cycle timer.

In fig. 12, as described above, in the period timer 720, the reference clock signal CLK _ ref may be any one of the resonant frequency signal LCosc and the reference frequency signal fref. The reference frequency signal fref may be a signal generated by an external crystal, and may be an oscillation signal such as PLL, RC, etc. in an Integrated Circuit (IC).

As an example, when the reference clock signal CLK _ ref is the resonant frequency signal LCosc received from the oscillation circuit, the sampling clock signal CLK _ spl may be the reference frequency signal fref. In this case, the frequency-divided oscillation signal may be "LCosc/M".

Alternatively, when the reference clock signal CLK _ ref is the reference frequency signal fref, the sampling clock signal CLK _ spl may be the resonant frequency signal LCosc. In this case, the frequency-divided oscillation signal may be "fref/N".

Fig. 13 is a block diagram showing an example of the touch detection circuit.

In fig. 13, the touch detection circuit 800 may differentiate the count value L _ CNT received from the frequency digitizer 700 to generate a difference value Diff, and may compare the difference value Diff with each of a predetermined falling threshold value F _ TH and a predetermined rising threshold value R _ TH to output a touch detection signal DF having a level for recognizing capacitive sensing (corresponding to a touch of a human body part) and inductive sensing (corresponding to a touch of a non-human body input member) based on the comparison result.

As an example, the touch detection circuit 800 may subtract the Delay count value L _ CNT _ Delay generated by delaying the count value L _ CNT by a predetermined time and the count value L _ CNT to generate a difference value Diff, and may compare the difference value Diff with the falling threshold value F _ TH and the rising threshold value R _ TH. The touch detection circuit 800 may output a touch detection signal Detect _ Flag having a first level when the difference Diff is less than the falling threshold F _ TH, and the touch detection circuit 800 may output a touch detection signal Detect _ Flag having a second level when the difference Diff is greater than the rising threshold R _ TH.

In fig. 13, the touch detection circuit 800 may include a delay circuit 810, a subtraction circuit 820, and a slope detection circuit 830.

The Delay circuit 810 may Delay the count value L _ CNT received from the frequency digitizer 700 by a time determined based on the Delay control signal Delay _ Ctrl to output a Delay count value L _ CNT _ Delay. The Delay time may be determined according to the Delay control signal Delay _ Ctrl.

The subtracting circuit 820 may subtract the Delay count value L _ CNT _ Delay and the count value L _ CNT to output a difference value. The count value L _ CNT corresponds to a current count value, and the Delay count value L _ CNT _ Delay corresponds to a value counted from the current to a predetermined Delay time.

The slope detection circuit 830 may compare the difference value Diff received from the subtraction circuit 820 with a predetermined falling threshold F _ TH and a predetermined rising threshold R _ TH, and may output a touch detection signal DF having a first level or a second level determined to recognize capacitive sensing (corresponding to a touch of a human body part) and inductive sensing (corresponding to a touch of a non-human body input member) based on the comparison result.

As an example, the slope detection circuit 830 may compare the difference Diff with a falling threshold F _ TH and a rising threshold R _ TH, and when the difference Diff is less than the falling threshold F _ TH, the slope detection circuit 830 may output a touch detection signal Detect _ Flag having a low level, and when the difference Diff is greater than the rising threshold R _ TH, the slope detection circuit 830 may output a touch detection signal Detect _ Flag having a high level.

As an example, the upper limit value FU _ Hys and the lower limit value FL _ Hys of the descent lag may be set and used based on the descent threshold value F _ TH. The upper limit value RU _ Hys and the lower limit value RL _ Hys of the rise hysteresis may be set and used based on the rise threshold R _ TH.

As described above, an error caused by temperature drift may be prevented using the difference value Diff of slopes, and touch detection accuracy may be improved using the upper limit value FU _ Hys and the lower limit value FL _ Hys of falling hysteresis and the upper limit value RU _ Hys and the lower limit value RL _ Hys of rising hysteresis. In fig. 13, RH _ Time denotes a predetermined Time for determining the falling hold and the rising hold.

Fig. 14 is a block diagram showing an example of the slope detection circuit in fig. 13.

In fig. 14, based on the falling detection signal F _ Det and the rising detection signal R _ Det, the detection signal generator 834 may generate a touch detection signal Detect _ Flag having a first level in a touch of a human body part when the difference Diff increases after falling, and the detection signal generator 834 may generate a touch detection signal Detect _ Flag having a second level in a touch of a non-human body input member when the difference Diff decreases after rising.

For example, in fig. 14, the slope detection circuit 830 may include a slope detector 831, a falling slope detector 832, a rising slope detector 833, and a detection signal generator 834.

The slope detector 831 determines whether the difference value Diff of the received slopes increases or decreases. For example, the slope detector 831 may determine whether the difference Diff decreases or increases, and when the difference Diff increases, the slope detector 831 may output the enable signal Enb in an active state as 1, and when the difference Diff decreases, the slope detector 831 may output the enable signal Enb in an inactive state as 0.

As an example, when the received difference value decreases, the slope detector 831 may output the enable signal Enb in an active state of 1 to the falling slope detector 832 and the rising slope detector 833 to start the operation. Meanwhile, when the received difference increases, the slope detector 831 may output the enable signal Enb equal to 0 to the falling slope detector 832 and the rising slope detector 833 not to perform an operation.

The falling slope detector 832 generates a falling detection signal F _ Det when the enable signal enters the active state Enb 1 and the received difference Diff is less than or equal to a falling threshold F _ TH for a predetermined Time FH _ Time.

The rising slope detector 833 generates a rising detection signal R _ Det when the enable signal enters the active state Enb 1 and the received difference Diff is greater than or equal to a rising threshold R _ TH for a predetermined Time RH _ Time. As an example, the rising slope detector 833 may generate the rising detection signal R _ Det when the enable signal enters the active state Enb of 1 and the difference Diff is greater than or equal to the values R _ TH, RU _ Hys, and RL _ Hys of the rising period for a predetermined Time RH _ Time.

The detection signal generator 834 may generate a touch detection signal Detect _ Flag having a first level or a second level based on the received falling detection signal F _ Det and the received rising detection signal R _ Det.

Further, the process of generating the touch detection signal Detect _ Flag is based on whether the falling detection signal F _ Det and the rising detection signal R _ Det are simultaneously activated and the activation Time interval PH _ Time of the signals F _ Det and R _ Det.

When the generation of the final touch detection signal Detect _ Flag is completed, the detection signal generator 834 may generate an initialization signal clr and transfer the initialization signal clr to the slope detector 831, the falling slope detector 832, and the rising slope detector 833.

Fig. 15 shows an example of a count value and a difference value (slope value of the count value) when touched by a human body part, and fig. 16 shows an example of a count value and a difference value when touched by a non-human body input member.

In fig. 15, the waveforms are examples of the waveform of the count value and the waveform of the difference (slope change) measured when the first coil element mounted below the first switching member is touched by a hand. In fig. 16, the waveforms are examples of waveforms of a count value and a difference value (slope change) measured when a conductor such as a metal touches a first coil element mounted below a first switching member.

In fig. 15, it can be seen that the first switching member on the first coil element operates in a capacitive manner to decrease the count value L _ CNT when a human body part (hand) touches the first switching member and to increase the count value L _ CNT to its initial state when the human body part (hand) does not touch the first switching member. If the slope value is checked based on the above phenomenon, it can be seen that the slope value decreases when touched by a human body part (hand) and increases when not touched by a human body part (hand).

As described above, when touched by a human body part (hand), the slope change (difference) appears as a pair of rising slopes following a falling slope.

In addition, in fig. 16, it can be seen that the first switching member on the first coil element operates inductively to increase the count value L _ CNT when the conductor (metal) touches the first switching member and to decrease the count value L _ CNT to its initial state when the conductor (metal) does not touch the first switching member.

As described above, when touched by a conductor (metal), the slope change (difference) appears as a pair of falling slopes after a rising slope.

For example, it can be seen that when a human body part (hand) or a conductor (metal) touches the first switch member on the first coil element, the slope change (a pair of rising slopes (corresponding to the human body part) and a pair of falling slopes (corresponding to the conductor)) and the order in which the falling slopes and the rising slopes occur change according to the touch input member.

Fig. 17 shows an example of a drift of the count value and the difference value when touched by a human body part.

In fig. 17, further, when the first coil element is continuously touched by a human body part (hand), a falling drift of the count value occurs due to a temperature change of the first coil element. For this reason, the slope change (rather than the absolute counter level) may be used to exclude effects caused by temperature drift to determine whether the first coil element is touched.

Therefore, the touch of the human body part (hand) can confirm that the slope in the initial state increases to the rising threshold or more after decreasing to the falling threshold or less.

Further, when a touch of a human body part and a touch of a conductor are mixed, both touches treat a falling slope and a rising slope as a pair, a touch of a human body part treats a rising slope after the falling slope as a pair, and a touch of a conductor treats a falling slope after the rising slope as a pair. Therefore, an operation (a falling slope after a rising slope) of a touch to a conductor can be detected and eliminated.

Further, when it is detected again that the drop below the drop threshold value is not raised after the drop below the drop threshold value in the initial state, the malfunction can be prevented by the initialization process.

Fig. 18 shows examples of the difference value change, the falling threshold value, the rising threshold value, and the touch detection signal.

In detail, fig. 18 shows examples of the falling threshold F _ TH and the rising threshold R _ TH, the falling hysteresis intervals FU _ Hys and FL _ Hys for the respective thresholds, and the rising hysteresis intervals RU _ Hys and RL _ Hys for the respective thresholds, and shows an example of the final touch detection signal Detect _ Flag for the respective thresholds.

The various thresholds and various hysteresis intervals described above may be stored by a user in a memory or register to be changed and reset depending on the state of the device or module.

Fig. 19 shows examples of various applications of the switch operation sensing device of the present application.

First to seventh application examples of the switch operation sensing device according to the present application are shown in fig. 19.

In fig. 19, the first application example may be an example of an operation control button applicable to an alternative bluetooth headset, and the second application example may be an example of an operation control button applicable to an alternative bluetooth ear headphone. As an example, the second application example may be applied to a power on/off switch instead of a bluetooth headset and a bluetooth headset.

In fig. 19, a third application example may be an example of an operation control button applicable to the substitute smart glasses. As an example, the third application example may be applied to a button for performing a function of a phone button, a mail button, a home button, or the like, instead of a device such as google glasses, a VR (virtual reality) head mounted device, an AR (augmented reality) head mounted device, or the like.

In fig. 19, a fourth application example may be an example of a door lock button applicable to an alternative vehicle. The fifth application example may be an example of a smart key button applicable to an alternative vehicle. The sixth application example may be an example of an operation control button applicable to an alternative computer. The seventh application example may be an example of an operation control button applicable to a substitute refrigerator.

Further, the switch operation sensing apparatus of the present application may be used to replace volume and power switches of laptop computers as well as switches of VR devices, Head Mounted Displays (HMDs), bluetooth ear buds, touch pens, and the like. In addition, the switch operation sensing apparatus may be used to replace a button of a monitor of a home appliance, a refrigerator, a laptop computer, or the like.

For example, the operation control buttons may be integrated with a cover, frame, or case of the device to which the operation control buttons are applied, and may be used to turn on/off power, adjust volume, and perform other specific functions (e.g., return, move to home, lock, etc.).

Further, the switch operation sensing device of the present application may include a plurality of touch switches to perform various functions while performing corresponding functions (e.g., return, move to home page, lock, etc.).

The touch switch of the present application is not limited to the above-described button of the device, and may be applied to devices such as mobile devices and wearable devices each having a switch. In addition, the touch switch of the present application can be applied to realize an integrated design.

When the above-described embodiments of the present application are applied to a mobile device, a thinner, simpler, more neat design can be achieved, and unlike a capacitive sensing method, a converter (ADC) is not required, and an application structure can be easily achieved by directly attaching a touch switch to a target surface of a switch member. Further, unlike capacitive sensing, a dustproof and waterproof switch can be realized, and sensing can be performed even in a humid environment.

As described above, in the touch switch structure using the case as the housing of the electronic device, the touch input member for the input operation may be recognized based on a change in slope including a change in capacitance and a change in inductance of the input member (such as a human body part or a non-human body input member) according to the input operation. Accordingly, sensing accuracy of touch input may be improved, and malfunction that may be caused by a touch error caused by a non-human body input member (not a human body part) may be prevented.

While the present disclosure includes particular examples, it will be apparent that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosure of the present application and its equivalents. The examples described herein are to be considered in a descriptive sense only and not for purposes of limitation. The description of features or aspects in each example will be considered applicable to similar features or aspects in other examples. Suitable results may be achieved if the described techniques were performed in a different order and/or if components in the described systems, architectures, devices, or circuits were combined in a different manner and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the present disclosure is defined not by the detailed description but by the claims and their equivalents, and all changes within the scope of the claims and their equivalents are to be construed as being included in the present disclosure.

Claims (23)

1. A switch operation sensing apparatus configured to be added to an electronic device, the switch operation sensing apparatus comprising:

an input operation unit including a first switch member provided in a housing;

an oscillation circuit configured to generate an oscillation signal whose resonance frequency changes during an input operation based on a change in capacitance or a change in inductance according to a touch input member in contact with the first switch member;

a frequency-to-digital converter configured to convert the oscillation signal into a count value; and

a touch detection circuit configured to: capacitive sensing and inductive sensing are detected based on a slope change of the count value received from the frequency-to-digital converter, and a corresponding touch detection signal is output based on the detection.

2. The switch-operation sensing device according to claim 1, wherein the corresponding touch detection signals have different levels from each other.

3. The switching operation sensing device of claim 1, wherein the frequency-to-digital converter is further configured to generate the count value by counting a reference clock signal using the oscillation signal.

4. The switch operation sensing device of claim 1, wherein the first switch member and the housing are formed from the same material.

5. The switch operation sensing device according to claim 4, wherein the input operation unit further includes a second switch member that is integrated with the housing and is provided at a position different from that of the first switch member, and

the second switch member and the housing are formed using the same material.

6. The switch operation sensing device of claim 1, wherein the oscillating circuit comprises:

an inductive circuit comprising a first coil element disposed on an inner side of the first switching member; and

a capacitive circuit comprising a capacitive element connected to the inductive circuit,

wherein the oscillating signal has a first frequency characteristic when the first switching member is touched by a human body part, and has a second frequency characteristic when the first switching member is touched by a non-human body input member.

7. The switch operation sensing device of claim 1, wherein the oscillating circuit comprises:

an inductance circuit including a first coil element disposed on an inner side of the first switching member and having an inductance that changes when the first switching member is touched by a non-human body input member; and

a capacitive circuit including a capacitive element connected to the inductive circuit and having a capacitance that changes when the first switching member is touched by a human body part.

8. The switch operation sensing device of claim 6, wherein the first coil element is mounted on a substrate and attached to an inside surface of the first switch member.

9. The switch operation sensing device of claim 1, wherein the frequency-to-digital converter is further configured to: a divided reference clock signal is generated by dividing a reference frequency signal by a reference dividing ratio, and the count value generated by counting the divided reference clock signal by the oscillation signal is output.

10. The switch operation sensing device of claim 1, wherein the frequency-to-digital converter is further configured to: the method includes generating a divided reference clock signal by dividing a reference frequency signal using a reference division ratio, dividing the oscillation signal from the oscillation circuit using a sensing division ratio, and outputting the count value generated by counting the divided reference clock signal using the divided oscillation signal.

11. The switching operation sensing device of claim 2, wherein the frequency-to-digital converter comprises:

a down-converter configured to: receiving a reference frequency signal as a reference clock signal and generating a divided reference clock signal by dividing the reference clock signal using a reference division ratio to down-convert a frequency of the reference frequency signal;

a cycle timer configured to: receiving the oscillation signal as a sampling clock signal, and outputting a cycle count value generated by counting the divided reference clock signal of one cycle time received from the down-converter using the sampling clock signal; and

a cascade integrator-comb filter circuit configured to output the count value generated by performing accumulation amplification on the cycle count value received from the cycle timer.

12. The switching operation sensing device of claim 11, wherein the cascaded integrator-comb filter circuit comprises a decimator cascaded integrator-comb filter configured to:

performing an accumulation amplification of the period count value from the period timer using a predetermined number of integration stages, a predetermined decimator factor, and a predetermined comb differential delay order; and

providing a cycle count value of the accumulated amplification.

13. The switch operation sensing device according to claim 12, wherein the touch detection circuit differentiates the count value received from the frequency-to-digital converter to generate a difference value, and compares the difference value with each of a predetermined falling threshold value and a predetermined rising threshold value to output the touch detection signal having one of the different levels for identifying capacitance sensing and inductance sensing based on a comparison result.

14. The switch-operation sensing device of claim 12, wherein the touch detection circuit comprises:

a delay circuit configured to: delaying the count value received from the frequency-to-digital converter by a time determined based on a delay control signal to output a delayed count value;

a subtraction circuit configured to: subtracting the count value from the delay count value to generate and output a difference value; and

a slope detection circuit configured to: comparing the difference value received from the subtraction circuit with each of a predetermined falling threshold value and a predetermined rising threshold value to output the touch detection signal having the first level or the second level for identifying capacitance sensing and inductance sensing based on a comparison result.

15. The switch operation sensing device of claim 14, wherein the slope detection circuit comprises:

a slope detector configured to: determining whether the difference decreases or increases, and outputting an enable signal in an active state when the difference decreases, and outputting an enable signal in an inactive state when the difference increases;

a falling slope detector configured to: generating a fall detection signal when the enable signal enters the active state and the difference is less than or equal to a fall threshold for a predetermined time;

a rising slope detector configured to: generating a rise detection signal when the enable signal enters the active state and the difference is greater than or equal to a rise threshold for the predetermined time; and

a detection signal generator configured to: generating the touch detection signal having a first level or a second level based on the falling detection signal and the rising detection signal.

16. The switch operation sensing device according to claim 15, wherein the detection signal generator generates the touch detection signal having a first level based on the falling detection signal and the rising detection signal in response to capacitance sensing when the difference increases after falling.

17. The switch operation sensing device according to claim 15, wherein the detection signal generator generates the touch detection signal having a second level based on the falling detection signal and the rising detection signal in response to an inductance sensing when the difference value decreases after rising.

18. The switch operation sensing apparatus of claim 1, wherein the electronic device is any one of a bluetooth headset, a bluetooth ear bud headset, smart glasses, a virtual reality headset, an augmented reality headset, a smart key button of a vehicle, a laptop computer, a head mounted display, and a stylus.

19. A detection apparatus, comprising:

a housing;

an input operation unit including a first switch member integrally formed with the housing;

an oscillation circuit configured to generate an oscillation signal based on a contact to a touch input member on the first switch member; and

a touch detection circuit configured to: one of capacitance sensing and inductance sensing is determined based on a slope change of a count value of the oscillation signal, and a detection signal is output based on the determined sensing.

20. The detection device of claim 19, wherein the oscillation circuit is further configured to: generating the oscillation signal having a resonance frequency corresponding to the touch input member contacting the first switch member during an input operation.

21. The detection device of claim 19, further comprising a frequency-to-digital converter connected to the oscillation circuit and configured to convert the oscillation signal to the count value.

22. The detection apparatus according to claim 19, wherein the input operation unit further includes a second switch member that is formed integrally with the housing and is provided at a position different from that of the first switch member.

23. The detection device of claim 19, wherein the contact of the touch input member is determined to be the capacitive sensing when the contact is a human touch and the contact is determined to be the inductive sensing when the contact of the touch input member is a non-human input member touch.

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