KR102185046B1 - Switching operatiion sensing apparatus capable of identifying a touch object, and electronic devices - Google Patents

Abstract

According to one embodiment of the present invention, an electronic device capable of improving the sensing precision of a touch input comprises: an operation input unit including a first switching member integrally formed with the housing; an oscillation circuit generating an oscillation signal having a resonant frequency, which is variable based on a capacitive change or an inductive change, according to an object of an operation input when the operation is inputted through the first switching member; a frequency digital converter converting the oscillation signal from the oscillation circuit into a count value; and a touch detection circuit identifying and detecting capacitive sensing and inductive sensing based on a slope change with respect to a count value inputted from the frequency digital converter, and outputting touch detection signals having different levels based on the detection.

Description

Switching operation sensing devices and electronic devices that can identify touch targets {SWITCHING OPERATIION SENSING APPARATUS CAPABLE OF IDENTIFYING A TOUCH OBJECT, AND ELECTRONIC DEVICES}

The present invention relates to a switching operation sensing device and an electronic device capable of identifying a touch object.

In general, a thinner, simpler, and neat design is preferred for wearable devices, and accordingly, existing mechanical switches are disappearing. This has been made possible by the implementation of dustproof and waterproof technologies and the development of a model with a sense of unity in a smooth design.

Currently, technologies such as ToM (touch on metal) technology that touches the metal, capacitor sensing technology using a touch panel, MEMS (Micro-Electro-Mechanical-System), and micro strain gauges are being developed. Furthermore, there is a trend of developing a force touch function.

In the case of the existing mechanical switch, a large size and space are required internally to implement the switch function, and the design and large space are not neat due to the shape that protrudes to the outside or the structure that is not integrated with the external case. The disadvantage is that it is necessary.

In addition, there is a risk of electric shock due to direct contact of a mechanical switch that is electrically connected, and in particular, there is a disadvantage in that it is difficult to prevent dust and waterproof due to the structure of the mechanical switch.

(Prior technical literature)

(Patent Document 1) KR 10-2002-0077836 (2002.10.14)

(Patent Document 2) KR 10-2009-0120709 (2009.11.25)

(Patent Document 3) KR 10-2011-0087014 (2011.08.02)

(Patent Document 4) KR 10-2011-0087004 (2011.08.02)

(Patent Document 5) KR 10-2018-0046833 (2018.05.09)

(Patent Document 6) US 2018-0093695 (2018.04.05)

(Patent Document 7) JP 2012-168747 (2012.09.06)

(Patent Document 8) JP 2015-095865 (2015.05.18)

An embodiment of the present invention uses a switching member that is integral with the housing of an electric device, and inputs manipulation based on a slope change of a capacitive change and an inductive change according to an object of manipulation input such as a human body or a non-human body. It provides a switching operation sensing device and an electronic device capable of identifying an object of.

According to an embodiment of the present invention, the operation input unit including a first switching member made integral with the housing; An oscillator circuit for generating an oscillation signal having a resonant frequency that is variable based on a capacitive change or an inductive change according to an object of the manipulation input when an operation input through the first switching member is input; A frequency digital converter converting the oscillation signal from the oscillation circuit into a count value; And a touch detection circuit that identifies and detects capacitive sensing and inductive sensing based on a slope change with respect to a count value input from the frequency digital converter, and outputs touch detection signals having different levels based on the detection. ; An electronic device comprising a is proposed.
In addition, according to an embodiment of the present invention, in the switching operation sensing device applied to an electronic device, including an operation input unit integrally formed with a housing, and the operation input unit including a first switching member, the first switching An oscillator circuit for generating an oscillation signal having a resonant frequency that is variable based on a change in capacitive or inductive according to an object of the manipulation input when an operation input through a member is input; A frequency digital converter converting the oscillation signal from the oscillation circuit into a count value; And a touch detection circuit that identifies and detects capacitive sensing and inductive sensing based on a slope change with respect to a count value input from the frequency digital converter, and outputs touch detection signals having different levels based on the detection. ; A switching operation sensing device comprising a is proposed.

According to an embodiment of the present invention, in a touch switching structure using a housing that is a case of an electric device, an operation input based on a slope change of a capacitive change and an inductive change according to an object of an operation input such as a human body or a non-human body The object of can be identified, and based on this, the sensing precision of the touch input can be improved, and a malfunction that may be caused by a contact error caused by a non-human body rather than a human body can be prevented.

1A and 1B are schematic external views of electronic devices to which the present invention is applied.
FIG. 2 is an exemplary view of a touch input sensor device including a cross-sectional structure taken along line I-I' of FIG. 1A.
3 is another exemplary view of a switching operation sensing device including a cross-sectional structure of line II′ of FIG. 1B.
4 is an exemplary diagram illustrating an oscillation circuit and a circuit part of a switching operation sensing device according to an embodiment of the present invention.
5 is an exemplary diagram of an oscillation circuit when there is no touch.
6 is a diagram illustrating a capacitive sensing method when a human body is touched.
7 is an exemplary diagram of an oscillation circuit when a human body is touched.
8 is a partial detailed exemplary diagram of the oscillation circuit of FIG. 7.
9 is an explanatory diagram of an inductive sensing method when a non-human body is touched.
10 is an exemplary diagram of an oscillation circuit when a non-human body is touched.
11 is an exemplary diagram of a frequency digital converter.
12 is a diagram illustrating the operation of a periodic timer.
13 is an exemplary diagram of a touch detection circuit.
14 is an exemplary diagram of the slope detection circuit of FIG. 13.
15 is an exemplary diagram of a count value and a difference value (a slope value of a count value) when a human body is touched.
16 is an exemplary diagram of a count value and a difference value when a non-human body is touched.
17 is an exemplary diagram for a drift and a difference value of a count value when a human body is touched.
18 is an exemplary diagram illustrating a difference value change, a polling threshold, a rising threshold, and a touch detection signal.
19 is a diagram illustrating an application of a switching operation sensing device according to an embodiment of the present invention.

Hereinafter, it is to be understood that the present invention is not limited to the described embodiments, and may be variously changed without departing from the spirit and scope of the present invention.

In addition, in each embodiment of the present invention, the structure, shape, and numerical values described as an example are only examples for helping the understanding of the technical matters of the present invention, and thus the spirit and scope of the present invention are not limited thereto. It should be understood that various changes can be made without departing. Embodiments of the present invention may be combined with each other to form various new embodiments.

In addition, in the drawings referred to in the present invention, components having substantially the same configuration and function in light of the overall contents of the present invention will be denoted by the same reference numerals.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to allow those of ordinary skill in the art to easily implement the present invention.

1A and 1B are schematic external views of electronic devices to which the present invention is applied.

Referring to (a) of FIG. 1, the electronic device 10 to which the present invention can be applied includes a touch screen 11, a housing 500, and a first switching member SM1 that replaces a mechanical button type switch. It may include a containing operation input unit (SWP).

Referring to (b) of FIG. 1, the electronic device 10 to which the present invention can be applied includes first and second switching members replacing the touch screen 11, the housing 500, and a mechanical button type switch ( It may include a manipulation input unit (SWP) including SM1, SM2).

1B shows a case where the operation input unit SWP includes the first and second switching members SM1 and SM2, but this is for convenience of explanation, and the two first and second 2 It can be understood that the number of switching members is not limited to the switching member, and the number of switching members may be expanded in the same manner as the first and second touch members.

For example, referring to FIGS. 1A and 1B, the electronic device 10 may be a portable mobile device, such as a smartphone, or a wearable device, such as a smart watch. In addition, it is not limited to a specific device, and may be a portable or wearable electronic device, or an electronic device having a switch for controlling an operation.

The housing 500 may be an outer case exposed to the outside of the electronic device. For example, when the switching operation sensing device is applied to a mobile device, it may be a cover disposed on the side (side) of the electronic device 10. For example, the housing 500 may be integrally formed with a cover disposed on the rear surface of the electronic device 10, or may be formed separately from a cover disposed on the rear surface of the electronic device 10.

In this way, the housing 500 may be an outer case of an electronic device, and it is not necessary to be limited to a specific location, shape, or structure.

Referring to FIG. 1B, each of the first and second switching members SM1 and SM2 may be disposed in the housing 500 of the electronic device, but is not limited thereto.

The first and second switching members SM1 and SM2 may be disposed on a cover of an electronic device. In this case, the cover may be disposed on a cover other than a touch screen, for example, a side cover, a rear cover, or a part of the front surface. It may be a cover that may be formed, and for convenience of description, as an example of a housing, a case of being disposed on a side cover of a mobile device will be described, but the present invention is not limited thereto.

FIG. 2 is an exemplary view of a touch input sensor device including a cross-sectional structure taken along line I-I' of FIG. 1A.

Referring to FIG. 2, the switching operation sensing device 50 according to an embodiment of the present invention includes an operation input unit (SWP), an oscillation circuit 600, a frequency digital converter 700, and a touch detection circuit 800. I can.

The manipulation input unit SWP may include at least one first switching member SM1 integrally formed with the housing 500 of the electronic device. For example, the first switching member SM1 may include the same material as that of the housing 500.

The oscillation circuit 600 is an oscillation signal LCosc having a resonant frequency that is variable based on a change in capacitive or inductive according to an object of the manipulation input when a manipulation input through the first switching member SM1 is input. Can be created. For example, the oscillation circuit 600 includes an inductance circuit 610 and a capacitance circuit 620. In this document, the manipulation object (or manipulation input object) may include a human body such as a human hand, and a non-human body such as plastic other than the human body. In this document, the manipulation input may be a concept including a touch input or a force input.

The frequency digital converter 700 may convert the oscillation signal LCosc from the oscillation circuit 600 into a count value. For example, the frequency digital converter 700 may convert the oscillation signal LCosc into a count value L_CNT in a frequency count method.

In addition, the touch detection circuit 800 identifies and detects capacitive sensing by the human body and inductive sensing by a non-human body based on the count value (L_CNT) input from the frequency digital converter 700). A touch detection signal (DF: Detect_Flag) having different levels based on detection may be output.

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

As an example, the manipulation input unit SWP includes a first switching member SM1, and the first switching member SM1 may be integrally formed with the housing 50, and accordingly, the first switching member ( SM1) may be made of the same material as that of the housing 500.

For example, if the housing 500 is a conductor such as metal, the first switching member SM1 may also be a conductor, and if the housing 500 is an insulator such as plastic, the first switching member SM1 is also an insulator. I can.

Referring to the front view of the first coil element in the direction A of FIG. 2, the inductance circuit 610 includes a first coil element 611 disposed inside the first switching member SM1 and having an inductance (Lind). can do.

The capacitance circuit 620 may include a capacitor element 621 connected to the inductance circuit 610 and having a capacitance Cext. For example, the capacitance circuit 620 may include a touch capacitance Ctouch generated when the manipulation input unit SWP is touched, and the touch capacitance Ctouch (FIG. 7) is shown in FIGS. 7 and 8 Together, the total capacitance of the oscillation circuit 600 can be increased.

For example, the first coil element 611 includes a coil pattern 611-P connected in a winding type between a first pad PA1 and a second pad PA2 disposed on the PCB substrate 611-S. can do.

Referring to FIG. 2, a first coil element 611 may be disposed on one side (eg, an upper surface) of the substrate 200, and a circuit portion is disposed on the other side (eg, a lower surface) of the substrate 200. Capacitor elements 621 such as (CS) and MLCC may be disposed.

For example, the circuit unit CS may be an integrated circuit including a part of the oscillation circuit 600, a frequency digital converter 700, and a touch detection circuit 800.

The board 200 may be a printed circuit board (PCB) or a flexible printed circuit board (FPCB), but is not limited thereto, and a board on which a circuit pattern can be formed (eg, one of various circuit boards including a PCB). ) Or a panel (eg, a panel for a panel level package (PLP)).

The structure of the switching operation sensing device shown in FIG. 2 is only an example, and the structure is not limited thereto.

Meanwhile, in FIG. 2, the first switching member SM1 has been described, but the description of the first switching member SM1 may also be applied to the second switching member SM2 (FIG. 1B). For example, in the case of including the first switching member SM1 and the second switching member SM2, one circuit unit CS may process different oscillation signals corresponding to each of the first and second switching members. I can.

For each drawing of the present invention, unnecessary and redundant descriptions of components having the same reference numerals and functions may be omitted, and possible differences may be described for each drawing.

The switching operation sensing device according to each embodiment of the present invention may include the plurality of switching members, in which case, the plurality of switching members may be arranged in a row, or a matrix arranged horizontally and vertically It can be structured.

Meanwhile, in (a) and (b) of FIG. 1, a case where the switching operation sensing device 50 includes one or two switching members is illustrated, but this is an example for convenience of description and is limited thereto. It doesn't work.

Accordingly, it can be understood that one and two as well as three or more switching members may be included.

In this document, the switching member is made integrally with the housing 500, wherein the integral means, regardless of the same or different material, is manufactured as one body at the time of manufacture, and after manufacture, the switching member is It is not a structure that cannot be separated from the housing, is not mechanically or mechanically separated, and may mean a single structure with no gaps at all.

Meanwhile, for example, the first coil element 611 may be a PCB coil element formed in a printed circuit board (PCB) pattern, but is not limited thereto.

For example, the first coil element 611 may be a PCB coil element implemented on a double-sided PCB or a multilayer PCB, but is not limited thereto.

For example, the first coil element 611 may be formed in various shapes such as a circle, a triangle, and a square, and is not particularly limited to the shape.

For each drawing of the present invention, unnecessary and redundant descriptions of components having the same reference numerals and functions may be omitted, and possible differences may be described for each drawing.

3 is another exemplary view of a switching operation sensing device including a cross-sectional structure taken along line I-I' of FIG. 1(b).

Referring to FIG. 3, a switching operation sensing device according to an embodiment of the present invention includes an operation input unit SWP including a first switching member SM1 and a second switching member SM2.

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

In addition, the inductance circuit 610 (FIG. 2) of the oscillation circuit 600 (FIG. 2) includes a first coil element 611 and a second coil element 612, and the capacitance of the oscillation circuit 600 (FIG. 2) The circuit 610 may include a capacitor element 621. The first coil element 611, the second coil element 612, the capacitor element 621, and the circuit unit CS may be mounted on the substrate 200.

The first coil element 611 may be disposed inside the first switching member SM1, and the second coil element 612 may be disposed inside the second switching member SM2.

The switching operation sensing device of the present invention may include a plurality of switching members, and in this case, corresponding to each of the plurality of switching members in order to generate different oscillation signals based on the touch of each of the plurality of switching members. It may include a plurality of coil elements.

For example, the first switching member SM1 and the second switching member SM2 may be made of the same material as that of the housing 500. If the housing 500 is a conductor such as metal, the first switching member SM1 and the second switching member SM2 may also be conductors. If the housing 500 is an insulator such as plastic, the first switching member SM1 and the second switching member SM1 2 The switching member SM2 may also be an insulator.

In addition, a first coil element 611 and a second coil element 612 may be disposed on one side (eg, an upper surface) of the substrate 200, and the other side (eg, a lower surface) of the substrate 200 A circuit unit CS and a capacitor element 621 such as an MLCC may be disposed on the surface). This arrangement structure is an example, and is not limited thereto.

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

As an example, when the conductors constituting the first and second switching members SM1 and SM2 are made of metal having high resistance (eg, 100 KΩ or more), two first and second switching members SM1 and SM2 Since interference between the liver can be reduced, it can actually be applied to electronic devices.

In this document, manipulation means a touch, force, or touch and force input through the manipulation input unit.

4 is an exemplary diagram illustrating an oscillation circuit and a circuit part of a switching operation sensing device according to an embodiment of the present invention.

Referring to FIG. 4, the switching operation sensing device according to an embodiment of the present invention may include an oscillation circuit 600, a frequency digital converter 700, and a touch detection circuit 800. The oscillation circuit 600 may include an inductance circuit 610 and a capacitance circuit 620 as described above.

In one example of the present invention, the oscillation circuit 600 may be, for example, an LC oscillation circuit, but is not limited thereto, and oscillation using a capacitance variable according to a human body touch or an inductance variable in a non-human touch It can be an oscillating circuit that generates a signal.

Meanwhile, the circuit unit CS may include a part of the oscillation circuit 600, a frequency digital converter 700, and a touch detection circuit 800. In this case, a part of the oscillation circuit 600 may be an amplifying circuit 630. For example, the amplifying circuit 630 may include an inverter or an amplifying element, and is not limited to the above example as long as the resonance signal can be maintained as an oscillation signal.

In addition, the circuit unit CS may or may not include a capacitor element. When the capacitor element 621 is not included in the circuit unit CS, the switching operation sensing device may include a capacitor element 621 such as an MLCC disposed independently from the circuit unit CS. In each embodiment of the present invention, the circuit unit CS may be an integrated circuit (IC) or may not be an integrated circuit (IC).

The frequency digital converter 700 divides a reference frequency signal (fref, FIG. 11) using a reference frequency division ratio (N) to generate the divided reference clock signal (DOSC_ref, FIG. 11), and the oscillation signal The divided reference clock signal DOSC_ref (FIG. 11) may be counted by using, and the count value L_CNT may be output.

The touch detection circuit 800 differentiates the count value L_CNT input from the frequency digital converter 700 to generate a difference value (Diff, FIG. 13), and the difference value (Diff, FIG. 13) and By comparing preset thresholds (F_THL, R_TH, FIG. 13), the touch detection signal DF (Detect_Flag) having a level for identifying a human or non-human touch may be output based on the comparison result.

In this document, the difference value Diff may correspond to a slope change value of a resonant frequency, a slope change value of a count value, or a derivative value.

In this document, the count value (L_CNT) is a digital value generated by a count processing operation by digital signal processing rather than analog signal processing. Accordingly, the count value L_CNT cannot be generated by signal amplification by a simple analog amplifier, and may be generated according to the count processing operation by the frequency digital converter 700 proposed in the present invention. Such a count processing operation requires a reference clock signal (eg, a reference frequency signal) and a sample clock signal (eg, an oscillation signal), which will be described later.

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

The inductance circuit 610 may include a first coil element 611 disposed inside the first switching member SM1, and the capacitance circuit 620 may include a capacitor element connected to the inductance circuit ( 621) may be included.

For example, the oscillation circuit 600 generates an oscillation signal LCosc having a first frequency characteristic when the first switching member SM1 is touched by the human body, and the first switching member SM1 is When touched by a human body, an oscillation signal LCosc having a second frequency characteristic may be generated.

For example, the inductance circuit 610 may include an inductance that is variable when the first switching member SM1 is touched by a non-human body, and the capacitance circuit 620 includes the first switching member SM1 It may include a capacitance that is changed when touched by the human body.

For example, the first coil element 611 may be mounted on the substrate 200 and attached to the inner surface of the first switching member SM1.

5 is an exemplary diagram of an oscillation circuit when there is no touch.

Referring to FIG. 5, the oscillation circuit 600 may include an inductance circuit 610, a capacitance circuit 620, and an amplifying circuit 630 as described above. Here, the amplifying circuit 630 may include at least one inverter INT or at least one amplifying element, and the oscillating circuit 600 may maintain the oscillating signal by the amplifying circuit 630.

The inductance circuit 610 may include an inductance (Lind) of the first coil element 611 when there is no non-human touch. The capacitance circuit 620 may include (Cext)(2Cext, 2Cext) of a capacitor element 621 such as an MLCC when there is no human body touch.

First, referring to FIG. 5, the oscillation circuit 600 includes an inductance circuit 610 including an inductance (Lind) of a first coil element 611 and a capacitance (Cext) (2Cext) of the capacitor element 621. ,2Cext) may be a parallel oscillation circuit including a capacitance circuit 620 including).

For example, when there is no touch such as a human body or a non-human body, the first resonant frequency fres1 of the oscillation circuit 600 may be expressed as Equation 1 below.

[Equation 1]

fres1 ≒ 1/2π sqrt (Lind * Cext)

In Equation 1, ≒ means that it may be the same or similar, and that similar means that other values may be further included.

Meanwhile, a resistor (not shown) may be further connected between the first coil element 611 and the capacitor element 621, which may perform an electrostatic discharge (ESD) function.

In the present invention, when a human body is touched according to an object touching the contact surface of the first switching member SM1 integrally formed with the housing 500 of the electronic device, a capacitive sensing method may be applied. When a human body is touched, an inductive sensing method may be applied, and accordingly, a human body and a non-human body can be distinguished among objects.

6 is a diagram illustrating a capacitive sensing method when a human body is touched, and FIG. 7 is an exemplary view of an oscillation circuit when a human body is touched.

Referring to FIGS. 6 and 7, when there is a human body touch, the capacitance circuit 620 of the oscillation circuit 600 may further include a touch capacitance (Ctouch) formed by the human body touch. The capacitance can be varied.

For example, when the human body (hand) touches the contact surface of the first switching member SM1, the capacitive sensing principle is applied, thereby increasing the total capacitance value. Accordingly, the resonant frequency (Equation 1) of the oscillation circuit 600 decreases.

In contrast, referring to FIGS. 9 and 10 below, when a non-human body such as a conductor (metal) touches the contact surface of the first switching member SM1, the principle of inductive sensing is applied to reduce the inductance due to the eddy current, resulting in resonance. The frequency will increase.

As described above, when a touch sensing switching structure in which the two sensing methods are mixed is used, it is possible to distinguish between a human body touch and a non-human touch according to an increase or decrease in the resonance frequency of the oscillation signal.

8 is a partial detailed exemplary diagram of the oscillation circuit of FIG. 7.

7 and 8, the oscillation circuit 600 includes a capacitance (Cext) (2Cext, 2Cext) of a capacitor element 621 included in the capacitance circuit 620, as well as a touch capacitance formed when a human body is touched. Ctouch) (Ccase, Cfinger, Cgnd) may be included.

8, the touch capacitance (Ctouch) (Ccase, Cfinger, Cgnd) is a case capacitance (Ccase) connected in series with each other, a finger capacitance (Cfinger), and a ground capacitance between the circuit ground and the earth (earth). (Cgnd) can be.

Accordingly, it can be seen that the total capacitance of the oscillation circuit 600 of FIG. 8 is variable compared to the oscillation circuit 600 of FIG. 5.

For example, when the capacitance (2Cext, 2Cext) is expressed as an equivalent circuit separated by one capacitance (2Cext) and another capacitance (2Cext) based on the circuit ground, the one capacitance (2Cext) or another The case capacitance Ccase, the finger capacitance Cfinger, and the ground capacitance Cgnd may be connected in parallel to one capacitance 2Cext.

For example, when there is a human body touch, the second resonant frequency fres2 of the oscillation circuit 600 may be expressed as Equation 2 below.

[Equation 2]

fres2 ≒ 1/{2π sqrt (Lind * [2Cext ∥ (2Cext + CT)])}

CT ≒ Ccase∥Cfinger∥Cgnd

In Equation 2, ≒ means that it may be the same or similar, and that similar means that other values may be further included. In Equation 2, Ccase is a parasitic capacitance that exists between the case (cover) and the first coil element 611, Cfinger is a capacitance that the human body has, and Cgnd is the circuit ground and earth. It is the ground return capacitance between.

And, in Equation 2, when ∥ is defined as follows,'a ∥ b'is a series connection of'a' and'b' in a circuit, and the sum value is'(a*b)/( It is defined as being calculated as a+b)'.

Comparing Equation 1 (when there is no touch) and Equation 2 (when there is a human body touch), since the capacitance (2Cext) of Equation 1 is increased to the capacitance (2Cext + CT) of Equation 2, the touch It can be seen that the absent first resonant frequency fres1 is lowered to the second resonant frequency fres2 with touch.

Again, referring to FIGS. 7 and 8, the oscillation circuit 600 is an oscillation signal having a first resonant frequency (fres1) when there is no human body touch or an oscillation having a second resonant frequency (fres2) when there is a human body touch A signal may be generated and output to the frequency digital converter 700.

9 is a diagram illustrating an inductive sensing method when a non-human body is touched, and FIG. 10 is an exemplary diagram of an oscillation circuit when a non-human body is touched.

9 and 10, when a non-human body such as a conductor (metal) touches the contact surface of the first switching member SM1, the principle of inductive sensing is applied so that the inductance by the eddy current decreases and the resonance frequency increases. do. In this way, a non-human touch can be detected based on an increase in the resonant frequency.

Referring to FIG. 10, when a non-human body such as metal is touch input to the first switching member SM1, inductance decreases due to a change in magnetic force between the first switching member SM1 and the first coil element 611 (Lind- ΔLind) increases the resonant frequency, and accordingly, a non-human touch can be detected.

Meanwhile, the principle of inductive sensing is as follows.

When the oscillator circuit is operated, AC current is generated in the inductor and a magnetic field (H-Field) is generated by this. At this time, when the metal is in contact, the inductor's magnetic field (H-Field) affects the metal to generate a circulating current, that is, an eddy current, and then a reverse magnetic field (H) by the eddy current. -Field) is generated, which decreases the inductance of the existing inductor as it operates in the direction of reducing the magnetic field (H-Field) of the inductor, and eventually increases the resonant frequency (sensing frequency).

In other words, depending on whether it is the human body (hand) or conductor (metal) that comes into contact with the switching member of the housing, it is determined whether the resonant frequency C (capacitance) changes or L (inductance) changes, thereby reducing the frequency, The increase is determined.

As described above, two types of sensing are possible using the structure of one touch sensing device, and a human body touch and a non-human touch can be detected, and they can be distinguished from each other. Explain

11 is an exemplary diagram of a frequency digital converter.

Referring to FIG. 11, the frequency digital converter 700 converts an oscillation signal LCosc into a count value L_CNT. As an example, the frequency digital converter 700 may count a reference frequency signal (reference clock signal) using an oscillation signal LCosc for a reference time (eg, one cycle). Unlike this, the frequency digital converter 700 May count the oscillation signal LCosc using a reference frequency signal (reference clock signal) for a reference time (eg, one cycle).

For example, as shown in Equation 3 below, the frequency digital converter 700 divides the reference frequency signal fref using the reference frequency division ratio N and divides the divided reference clock signal (DOSC_ref = fref/ N) is generated, and the oscillation signal (LCosc) from the oscillation circuit 600 is divided using a sensing frequency division ratio (M), and the divided oscillation signal (LCosc)/M) is used. The count value LC_CNT generated by counting the reference clock signal DOSC_ref may be output.

Conversely, the divided reference signal may be counted using the divided sensing signal.

[Equation 3]

L_CNT = (N * LCosc)/(M * fref)

In Equation 3, LCosc is the frequency (oscillation frequency) of the oscillation signal, fref is the reference frequency, N is the reference frequency (eg, 32Khz) division ratio, and M is the division ratio of the resonance frequency.

As shown in Equation 2, dividing the oscillation frequency (LCosc) by the reference frequency (fref) means that the period of the reference frequency (fref) is counted by using the resonance frequency (LCosc), in this manner. If the count value L_CNT is calculated as, it is possible to use a low reference frequency fref, and there is an advantage in that the accuracy of the count can be increased.

Referring to FIG. 11, the frequency digital converter (CDC) 700 may include a frequency down converter 710, a period timer 720, and a Cascaded Integrator-Comb (CIC) filter circuit 730.

The frequency down converter 710 receives the reference clock signal CLK_ref, which is the reference of the time period of the timer to be counted, and reduces the frequency of the reference clock signal CLK_ref.

For example, the reference clock signal CLK_ref input to the frequency down converter 710 may be 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 sensing frequency signal LCosc has a frequency down such as'DOSC_ref = LCosc /M', where M is externally It can be set in advance. As another example, when the reference clock signal CLK_ref is the reference frequency signal fref, the reference clock signal CLK_ref is frequency down, such as'DOSC_ref = fref /N', where N is externally Can be set.

The period timer 720 counts one period time of the divided reference clock signal DOSC_ref input from the frequency down converter 710 using a sample clock signal CLK_spl, and generates a period count value (PCV). Can be printed.

For example, the CIC filter circuit 730 may include the decimator CIC filter, and the decimator CIC filter is a count value (L_CNT) generated by performing cumulative amplification on the received period count value (L_CNT). Can be printed.

As another example, the CIC filter circuit 730 may further include a primary CIC filter. The primary CIC filter may remove noise by taking a moving average of the output from the decimator CIC filter.

For example, the decimator CIC filter performs a cumulative amplification on the period count value from the period timer using the accumulated gain determined based on a preset integration stage order, a decimator factor, and a comb derivative delay order. And, it is possible to provide the accumulated amplified period count value.

For example, if the decimator CIC filter includes an integrating circuit, a decimator and a derivative circuit, based on the stage order (S) of the integrating circuit, the decimator factor (R), and the delay order (M) of the derivative circuit The cumulative gain can be obtained as [(R*M)^S]. For example, when the stage order (S) of the integrating circuit is 4, the decimator factor (R) is 1, and the delay order (M) of the derivative circuit is 4, the accumulated gain is 256[(1*4)^4] Can be

12 is a diagram illustrating the operation of a periodic timer.

Referring to FIG. 12, as described above, in the period timer 720, the reference clock signal CLK_ref may be any one of the resonance frequency signal LCosc and the reference frequency signal fref. The reference frequency signal (fref) can be a signal by an external crystal and can be an oscillation signal such as an IC internal PLL or RC.

For example, if the reference clock signal CLK_ref is a resonant frequency signal LCosc input from the oscillation circuit, the sample clock signal CLK_spl may be a reference frequency signal fref. In this case, the divided oscillation signal is Can be'LCosc /M'.

Alternatively, if the reference clock signal CLK_ref is the reference frequency signal fref, the sample clock CLK_spl may be a resonance frequency signal LCosc, and in this case, the divided oscillation signal may be'fref /N'. .

13 is an exemplary diagram of a touch detection circuit.

13, the touch detection circuit 800 differentiates the count value L_CNT received from the frequency digital converter 700 to generate a difference value Diff, and calculates the difference value Diff. Compared with each of a preset polling threshold (F_TH) and a rising threshold (R_TH), and outputs the touch detection signal DF having a level for discriminating a touch by capacitive sensing and a non-human body based on the comparison result can do.

For example, the touch detection circuit 800 generates a difference value (Diff) by subtracting a delay count value (L_CNT_Delay) generated by delaying the count value (L_CNT) by a preset time and the count value (L_CNT). And, comparing the difference value (Diff) with the polling threshold (F_TH) and the rising threshold (R_TH), if the difference value (Diff) is less than the polling threshold, outputs a touch detection signal (Detect_Flag) of the first level, Alternatively, when the difference value Diff is greater than a rising threshold, a second level touch detection signal Detect_Flag may be output.

Referring to 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 input from the frequency digital converter 700 by a time determined based on the delay control signal Delay_Ctrl, and output a delay count value L_CNT_Delay. Here, the delay time may be determined according to the delay control signal Delay_Ctrl.

The subtraction circuit 820 subtracts the delay count value L_CNT_Delay and the count value L_CNT, and outputs a difference value. The count value L_CNT corresponds to the current counted value, and the delay count value L_CNT_Delay corresponds to a value counted before a predetermined delay time from the present.

The slope detection circuit 830 compares the difference value Diff received from the subtraction circuit 820 with each of a preset polling threshold F_TH and a rising threshold R_TH, and based on the comparison result, the capacitive The touch detection signal DF having a determined first level or a second level for sensing and identifying a touch caused by a non-human body may be output.

As an example, the slope detection circuit 830 compares a difference value (Diff) for a slope output from the subtraction circuit 820 with a polling threshold value (F_TH) and a rising threshold value (R_TH), and the difference value (Diff) is polled. If it is smaller than the threshold value, a low-level touch detection signal Detect_Flag is output. Unlike this, when the difference value Diff is greater than the rising threshold, a high-level touch detection signal Detect_Flag may be output.

For example, based on the polling threshold F_TH, an upper limit value FU_Hys and a lower limit value FL_Hys of polling hysteresis may be set and used. Based on the rising threshold R_TH, an upper limit value RU_Hys and a lower limit value RL_Hys of rising hysteresis may be set and used.

As described above, if the difference value (Diff) for the slope is used, an error for temperature drift can be prevented, and the upper and lower limits of polling hysteresis (FU_Hys, FL_Hys) and the upper and lower limits of rising hysteresis (RU_Hys, RL_Hys) are used. Touch detection accuracy can be improved. In FIG. 13, RH_Time is a predetermined time for determining polling maintenance and rising maintenance.

14 is an exemplary diagram of the slope detection circuit of FIG. 13.

Referring to FIG. 14, the detection signal generator 834 refers to a touch by the human body when the difference value Diff rises after falling, based on the polling detection signal F_Det and the rising detection signal R_Det. A touch detection signal (Detect_Flag) having a first level is generated, and when the difference value (Diff) rises and falls, a touch detection signal (Detect_Flag) having a second level indicating a non-human touch can be generated. have.

For example, referring to 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. have.

The slope detector 831 determines whether the input slope difference value (Diff) is polling (falling) or rising (rising). For example, the slope detector 831 determines whether the difference value Diff is polling (falling) or rising (rising), and when polling (falling), an active enable signal (Enb = 1) is generated. Output, and if rising (rising), an enable signal (Enb=0) in an inactive state may be output.

For example, if the input difference value is polling (falling), an active enable signal (Enb = 1) to start an operation is output to the polling slope detector 832 and the rising slope detector 833, and rising (rising). In this case, an inactive enable signal (Enb=0) in which no operation is performed is output.

When the enable signal becomes active (Enb=1), the polling slope detector 832, when the input difference value (Diff) falls below the polling threshold (F_TH) for a predetermined time (FH_Time), the polling detection signal ( F_Det) is generated.

Rising slope detector 833, when the enable signal is in the active state (Enb = 1), when the input difference value (Diff) is equal to or greater than the rising threshold value (R_TH) for a predetermined time (RH_Time), the rising detection signal ( R_Det) is generated. As an example, the rising slope detector 833, when the enable signal is in the active state (Enb = 1), the difference value (Diff) is more than a rising period (R_TH, RU_Hys, RL_Hys) for a predetermined time (RH_Time) When the value is reached, a rising detection signal R_Det may be generated.

The detection signal generator 834 may generate the touch detection signal Detect_Flag having a first level or a second level based on the input polling detection signal F_Det and the rising detection signal R_Det.

In other words, the process of generating the touch detection signal (Detect_Flag) includes whether the polling detection signal (F_Det) and the rising detection signal (R_Det) are simultaneously activated, and activation of the signals (F_Det, R_Det). It can be generated based on the time interval (PH_Time).

When the generation of the final touch detection signal (Detect_Flag) is completed, the detection signal generator 834 generates an initialization signal (clr) to the slope detector 831, the polling slope detector 832, and the rising slope detector 833 Can be provided.

FIG. 15 is an exemplary diagram of a count value and a difference value (a slope value of a count value) when a human body is touched, and FIG. 16 is an exemplary diagram of a count value and a difference value when a non-human body is touched.

First, the waveform of FIG. 15 is an exemplary diagram of a waveform for a difference value that is a change in a slope and a count value measured when a first coil element mounted under the first switching member is contacted with a human body (hand). The waveform is an example of a waveform for a difference value, which is a measured count value and a slope change when contacted with a conductor such as metal.

Referring to FIG. 15, when the first switching member on the first coil element is touched by the human body (hand), the counter value L_CNT decreases and the human body (hand) becomes a non-contact state by operating in a capacitive manner. If so, it can be seen that the count value (L_CNT) increases to its original state. If the slope value is checked based on this phenomenon, it can be confirmed that it descends when contacted and rises when non-contact.

In this way, when the human body (hand) is touched, it can be seen that the slope change, which is the difference value, appears as a pair of rising slopes after the polling slope.

In contrast, referring to FIG. 16, when the first switching member above the first coil element is contacted with a conductor (metal), the counter value (L_CNT) increases and the conductor (metal) operates in an inductive manner. It can be seen that the count value (L_CNT) decreases to the original state in case of disconnection.

In this way, when a conductor (metal) is touched, it can be seen that the slope change, which is the difference value, appears as a pair of the falling slope after the rising slope.

That is, when a human body (hand) or a conductor (metal) touches the first switching member on the first coil element, the slope change must appear as a pair of the falling slope and the rising slope, and the order in which the falling slope and the rising slope appear. It can be seen that is different according to the touch object.

17 is an exemplary diagram for a drift and a difference value of a count value when a human body is touched.

Referring to FIG. 17, when the first coil element is continuously contacted by the human body (hand), a downward drift of the counter value occurs due to a temperature change of the first coil element. For this reason, if an absolute counter level is not used and a slope change is used to determine contact or not, the influence by temperature drift can be excluded.

Accordingly, in the initial state of contact with the human body (hand), the change of the slope falls below the polling threshold and then rises above the rising threshold.

In addition, when the contact between the human body and the conductor is mixed, both the touch of the human body and the touch of the conductor are treated as a pair of the falling slope and the rising slope, and the human body uses the rising slope as a pair after the falling slope, and the conductor (metal ) Makes the falling slope after the rising slope one phase, so it is possible to detect and remove the motion of the touch of the conductor (falling slope after the rising slope).

In addition, if a fall below the polling threshold is detected without rising after falling below the polling threshold in the initial state, a malfunction can be prevented through initialization.

18 is an exemplary diagram illustrating a difference value change, a polling threshold, a rising threshold, and a touch detection signal.

FIG. 18 is a description of a polling threshold (F_TH), a rising threshold (R_TH), a polling hysteresis period (FU_Hys, FL_Hys) and a rising hysteresis period (RU_Hys, RL_Hys) for each threshold, and a final touch detection signal for each threshold. An example of (Detect Flag) is shown.

Each of the above-described thresholds and hysteresis sections can be changed and reset according to the state of the set or module by storing them in a memory (EEPROM or Register) by the user.

19 is a diagram illustrating an application of a switching operation sensing device according to an embodiment of the present invention.

Referring to FIG. 19, a plurality of application examples 1 to 7 of a switching operation sensing device according to an embodiment of the present invention are shown.

Application example 1 of FIG. 19 is an example that can be applied in place of an operation control button of a Bluetooth headset, and application example 2 of FIG. 19 is an example that can be applied by replacing an operation control button of a Bluetooth headset. For example, it may be applied by replacing the on/off power switch of a Bluetooth headset and a Bluetooth earphone.

Application example 3 of FIG. 19 is an example that can be applied in place of a button for controlling the operation of glasses. For example, it may be applied by replacing buttons that perform functions such as phone, mail, and home buttons of devices such as Google Glass, VR, and AR.

Application example 4 of FIG. 19 is an example that can be applied by replacing a door lock button of a vehicle. Application example 5 of FIG. 19 is an example that can be applied by replacing a button of a smart key of a vehicle. Application example 6 in Fig. 19 is an example that can be applied in place of a button for operation control of a computer. In addition, Application Example 7 of FIG. 19 is an example that can be applied in place of an operation button for controlling the operation of a refrigerator.

In addition, it can be used by replacing the volume and power switch of the laptop, switches such as VR, HMD (Head Mounted Display), Bluetooth earphone, and style rush touch fan, and also replaces buttons of monitors, refrigerators, and laptops of home appliances. Can be used.

For example, a button for operation control may be integrated and disposed in a cover or frame or housing of a device to be applied, and is used to perform power on/off, volume control, and other specific functions (backward, home movement, locking, etc.). Can be used.

In addition, a plurality of touch switches may be included to perform a plurality of functions in performing a corresponding function (backward movement, home movement, locking, etc.).

The touch switch of the present invention is not limited to the above-mentioned devices, and can be applied to portable devices such as mobiles and wearables with switches. Also, by applying the touch switch of the present invention, an integrated design can be implemented.

When the above-described embodiment of the present invention is applied to a mobile device, it is possible to implement a thinner, simpler, and clean design, and unlike the capacitive sensing method, there is no need for a converter (ADC), and the application structure is applied directly to the target surface of the switching member. It has the advantage that it can be easily implemented because there is no spacer structure, and it is possible to implement a dustproof and waterproof switch, and it is possible to sense differently from capacitive sensing even in a humid environment.

In the above, the present invention has been described as an example, but the present invention is not limited to the above-described embodiment, and those of ordinary skill in the field to which the present invention belongs without departing from the gist of the present invention claimed in the claims Anyone can make a variety of variations.

200: substrate
500: housing
600: oscillation circuit
611,612: first and second coil elements
700: frequency digital converter
800: touch detection circuit
SWP1, SWP2: 1st, 2nd touch switch
CS: Integrated circuit

Claims (30)

An operation input unit including a first switching member integrally formed with the housing;
An oscillator circuit for generating an oscillation signal having a resonant frequency that is variable based on a capacitive change or an inductive change according to an object of the manipulation input when an operation input through the first switching member is input;
A frequency digital converter converting the oscillation signal from the oscillation circuit into a count value; And
A touch detection circuit for identifying and detecting capacitive sensing and inductive sensing based on a slope change with respect to a count value input from the frequency digital converter, and outputting touch detection signals having different levels based on the detection;
Electronic device comprising a.
The method of claim 1, wherein the frequency digital converter
Counting a reference clock signal using the oscillation signal to generate the count value
Electronics.
The method of claim 2, wherein the first switching member,
An electronic device comprising the same material as that of the housing.
The method of claim 3, wherein the operation input unit
Further comprising a second switching member formed integrally with the housing and disposed at a different position from the first switching member,
The second switching member includes the same material as that of the housing.
The method of claim 1, wherein the oscillation circuit,
An inductance circuit including a first coil element disposed inside the first switching member; And
A capacitance circuit including a capacitor element connected to the inductance circuit; Including,
The oscillation circuit,
When the first switching member is touched by a human body, an oscillation signal having a first frequency characteristic is generated, and when the first switching member is touched by a non-human body, an oscillation signal having a second frequency characteristic is generated,
Electronics.
The method of claim 1, wherein the oscillation circuit,
An inductance circuit including a first coil element disposed inside the first switching member and having an inductance that varies when the first switching member is touched by a non-human body; And
A capacitance circuit including a capacitor element connected to the inductance circuit, and having a capacitance that changes when the first switching member is touched by a human body;
Electronic device comprising a.
The method of claim 5, wherein the first coil element
Mounted on the substrate and attached to the inner surface of the first switching member
Electronics.
The method of claim 1, wherein the frequency digital converter
Dividing a reference frequency signal using a reference frequency division ratio to generate a divided reference clock signal, and outputting the count value generated by counting the divided reference clock signal using the oscillation signal.
Electronics.
The method of claim 1, wherein the frequency digital converter
A reference frequency signal is divided using a reference frequency division ratio to generate a divided reference clock signal, the oscillation signal from the oscillation circuit is divided using a sensing frequency division ratio, and the division is performed using the divided oscillation signal To output the count value generated by counting the reference clock signal
Electronics.
The method of claim 1, wherein the frequency digital converter
A frequency down converter configured to receive a reference frequency signal as a reference clock signal, divide the reference clock signal using a reference frequency division ratio to generate a divided reference clock signal, and to down the frequency of the reference frequency signal;
A period timer for receiving the oscillation signal as a sample clock signal and outputting a period count value generated by counting one period time of the divided reference clock signal received from the frequency down converter using the sample clock signal; And
A CIC filter circuit for outputting the count value generated by performing cumulative amplification on the period count value input from the period timer;
Electronic device comprising a.
The method of claim 10, wherein the CIC filter circuit,
A decimator CIC filter for outputting the count value generated by performing cumulative amplification on the period count value input from the period timer,
The decimator CIC filter performs cumulative amplification on the period count value from the period timer by using the cumulative gain determined based on a preset integration stage order, a decimator factor, and a comb derivative delay order, and An electronic device that provides an amplified period count value.
The method of claim 11, wherein the touch detection circuit,
Differentiating the count value received from the frequency digital converter to generate a difference value, comparing the difference value with each of a preset polling threshold and a rising threshold, and performing capacitive sensing and inductive sensing based on the comparison result. Outputting the touch detection signal having a level for identification
Electronics.
The method of claim 12, wherein the touch detection circuit,
A delay circuit for delaying the count value received from the frequency digital converter by a time determined based on a delay control signal, and outputting a delay count value;
A subtraction circuit outputting a difference value generated by subtracting the count value from the delay count value from the delay circuit; And
Comparing the difference value input from the subtraction circuit with each of a preset polling threshold and a rising threshold, and having a determined first level or a second level for discriminating capacitive sensing and inductive sensing based on the comparison result. A slope detection circuit for outputting the touch detection signal;
Electronic device comprising a.
The method of claim 13, wherein the slope detection circuit,
A slope detector that determines whether the difference value is polling (falling) or rising (rising), outputting an active enable signal if polling (falling), and outputting an inactive enable signal if rising (rising) ;
A polling slope detector 832 that generates a polling detection signal when the enable signal is in an active state and the difference value is less than or equal to a polling threshold for a predetermined time;
A rising slope detector generating a rising detection signal when the enable signal is in an active state and a difference value exceeds a rising threshold for a predetermined time; And
A detection signal generator for generating the touch detection signal having a first level or a second level based on the polling detection signal and the rising detection signal;
Electronic device comprising a..
The method of claim 14, wherein the detection signal generator,
On the basis of the polling detection signal and the rising detection signal, if the difference value rises after falling, generating a touch detection signal having a first level indicating a touch by a human body
Electronics.
The method of claim 14, wherein the detection signal generator,
On the basis of the polling detection signal and the rising detection signal, when the difference value rises and falls, generating a touch detection signal having a second level indicating inductive sensing
Electronics.
In the switching operation sensing device applied to an electronic device comprising an operation input unit made integral with the housing, the operation input unit including a first switching member,
An oscillator circuit for generating an oscillation signal having a resonant frequency that is variable based on a capacitive change or an inductive change according to an object of the manipulation input when an operation input through the first switching member is input;
A frequency digital converter converting the oscillation signal from the oscillation circuit into a count value; And
A touch detection circuit for identifying and detecting capacitive sensing and inductive sensing based on a slope change with respect to a count value input from the frequency digital converter, and outputting touch detection signals having different levels based on the detection;
Switching operation sensing device comprising a.
The method of claim 17, wherein the frequency digital converter
Counting a reference clock signal using the oscillation signal to generate the count value
Switching operation sensing device.
The method of claim 17, wherein the oscillation circuit,
An inductance circuit including a first coil element disposed inside the first switching member; And
A capacitance circuit including a capacitor element connected to the inductance circuit; Including,
The oscillation circuit,
When the first switching member is touched by a human body, an oscillation signal having a first frequency characteristic is generated, and when the first switching member is touched by a non-human body, an oscillation signal having a second frequency characteristic is generated,
Switching operation sensing device.
The method of claim 17, wherein the oscillation circuit,
An inductance circuit including a first coil element disposed inside the first switching member and having an inductance that varies when the first switching member is touched by a non-human body; And
A capacitance circuit including a capacitor element connected to the inductance circuit, and having a capacitance that changes when the first switching member is touched by a human body;
Switching operation sensing device comprising a.
The method of claim 19, wherein the first coil element
Mounted on the substrate and attached to the inner surface of the first switching member
Switching operation sensing device.
The method of claim 17, wherein the frequency digital converter
Dividing a reference frequency signal using a reference frequency division ratio to generate a divided reference clock signal, and outputting the count value generated by counting the divided reference clock signal using the oscillation signal.
Switching operation sensing device.
The method of claim 17, wherein the frequency digital converter
A reference frequency signal is divided using a reference frequency division ratio to generate a divided reference clock signal, the oscillation signal from the oscillation circuit is divided using a sensing frequency division ratio, and the division is performed using the divided oscillation signal To output the count value generated by counting the reference clock signal
Switching operation sensing device.
The method of claim 17, wherein the frequency digital converter
A frequency down converter configured to receive a reference frequency signal as a reference clock signal, divide the reference clock signal using a reference frequency division ratio to generate a divided reference clock signal, and to down the frequency of the reference frequency signal;
A period timer for receiving the oscillation signal as a sample clock signal and outputting a period count value generated by counting one period time of the divided reference clock signal received from the frequency down converter using the sample clock signal; And
A CIC filter circuit for outputting the count value generated by performing cumulative amplification on the period count value input from the period timer;
Switching operation sensing device comprising a.
The method of claim 24, wherein the CIC filter circuit,
A decimator CIC filter for outputting the count value generated by performing cumulative amplification on the period count value input from the period timer,
The decimator CIC filter performs cumulative amplification on the period count value from the period timer by using the cumulative gain determined based on a preset integration stage order, a decimator factor, and a comb derivative delay order, and A switching operation sensing device that provides an amplified period count value.
The method of claim 25, wherein the touch detection circuit,
Differentiating the count value received from the frequency digital converter to generate a difference value, comparing the difference value with each of a preset polling threshold and a rising threshold, and performing capacitive sensing and inductive sensing based on the comparison result. Outputting the touch detection signal having a level for identification
Switching operation sensing device.
The method of claim 26, wherein the touch detection circuit,
A delay circuit for delaying the count value received from the frequency digital converter by a time determined based on a delay control signal, and outputting a delay count value;
A subtraction circuit outputting a difference value generated by subtracting the count value from the delay count value from the delay circuit; And
Comparing the difference value input from the subtraction circuit with each of a preset polling threshold and a rising threshold, and having a determined first level or a second level for discriminating capacitive sensing and inductive sensing based on the comparison result. A slope detection circuit for outputting the touch detection signal;
Switching operation sensing device comprising a.
The method of claim 27, wherein the slope detection circuit,
A slope detector that determines whether the difference value is polling (falling) or rising (rising), outputting an active enable signal if polling (falling), and outputting an inactive enable signal if rising (rising) ;
A polling slope detector 832 that generates a polling detection signal when the enable signal is in an active state and the difference value is less than or equal to a polling threshold for a predetermined time;
A rising slope detector generating a rising detection signal when the enable signal is in an active state and a difference value exceeds a rising threshold for a predetermined time; And
A detection signal generator for generating the touch detection signal having a first level or a second level based on the polling detection signal and the rising detection signal;
Switching operation sensing device comprising a.
The method of claim 28, wherein the detection signal generator,
On the basis of the polling detection signal and the rising detection signal, if the difference value rises after falling, generating a touch detection signal having a first level indicating a touch by a human body
Switching operation sensing device.
The method of claim 28, wherein the detection signal generator,
On the basis of the polling detection signal and the rising detection signal, when the difference value rises and falls, generating a touch detection signal having a second level indicating inductive sensing
Switching operation sensing device.

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