KR20210000177A - Inductive force sensor and mathod of operation thereof - Google Patents

Abstract

Disclosed are an inductive force sensor and an operation method thereof. According to one embodiment of the present invention, the inductive force sensor for recognizing a user gesture pattern comprises: a reference resonant circuit; a first resonant circuit; and a determination circuit obtaining information on a first resonant frequency and a reference resonant frequency due to a first inductance formed in an inductive coil based on a displacement between a target and an inductive coil formed by an external force inputted in a Z-axis direction. The determination circuit determines the displacement of the target and the external force in the Z-axis direction based on the first resonance frequency and the reference resonance frequency.

Description

Inductive force sensor and its operation method {INDUCTIVE FORCE SENSOR AND MATHOD OF OPERATION THEREOF}

The present invention relates to a force sensor and a method of operation thereof, and specifically, a target layer and a printed circuit board (PCB), or a flexible printed circuit board (FBCB) by an external force, or a transparent electrode. The present invention relates to an inductive force sensor that senses a degree of applied force using an inductance that varies according to a change in distance between formed coils, and an operating method thereof.

The recent touch recognition technology has made rapid progress, and in a two-dimensional touch recognition technology that recognizes a touch position using coordinates on the X and Y axes, the strength of the touch (the force applied in the Z-axis direction 3D touch recognition function that enriches the user interface by detecting the size) has emerged.

APPLE INC's 3D touch has introduced a technology that differentiates and recognizes the intensity of a touch by combining a touch sensor and a pressure sensor. However, the method of combining the pressure sensor with the touch sensor increases the hardware manufacturing cost, and the sensitivity of the pressure sensor is not high, so it is difficult to accurately recognize the user's touch strength.

US 2017/0269754 "Dual Touch Sensor Architecture With XY-Position And Z-Force Sensing For Touch-On-Surface Button" of Texas Instruments Inc. is a combination of a capacitive touch sensor and an inductive sensor. The position on the XY plane of is recognized by the capacitive touch sensor, and the touch force in the Z-axis direction at the touch position is recognized by the inductive sensor.

Another US published patent US 2018/0180450 "Inductive Touch Input" of Texas Instruments Inc. uses a plurality of inductive touch sensors to detect whether or not touch and force are touched at different locations, and whether or not to touch and the movement pattern of the touch force To recognize the touch scroll gesture.

As a prior art that detects the user's intention to lock or unlock the car door by applying such a 3D touch force recognition technology, Korean Patent Publication No. KR 10-2017-0007127 and US Patent Publication US 2017 /0016255 "Device for Detecting a User's Intention to Lock or Unlock a Motor Vehicle Door", etc., as a prior document that implements an inductive force sensor by implementing a coil on a flexible printed circuit board (FPCB). Korean Patent Registration KR 10-1920440 "Self Inductive Force Sensor Module for 3D Touch Implementation", Korean Patent Registration KR 10-1954368 "Mutual Inductive Force Sensor Module for 3D Touch Implementation" have been introduced.

Prior literature that detects the touch force using an inductive sensor introduces a technology that recognizes the touch force by selecting a new material or part such as the arrangement of parts and elements, and FPCB. However, when using only the inductive sensor, the touch position and touch There is a problem in that the precision of sensing force is low, and the hardware cost increases when the inductive sensor and other sensors are combined.

In addition, due to the recent emergence of mobile devices and smart devices, various needs for user interfaces and user experiences exist, and in order to meet these needs, a technology that recognizes the touch force by dividing each fine area is required. Densely arranged, but a technique for distinguishing and recognizing each sensor is also required, and it is difficult to meet such a demand with the prior techniques.

US Patent Publication US 2017/0269754 "Dual Touch Sensor Architecture With XY-Position And Z-Force Sensing For Touch-On-Surface Button" (September 21, 2017) US Patent Publication US 2018/0180450 "Inductive Touch Input" (June 28, 2018) Korean Patent Publication KR 10-2017-0007127 "Device that detects the intention of a user to lock or unlock a car door" (January 18, 2017) US Patent Publication US 2017/0016255 "Device for Detecting a User's Intention to Lock or Unlock a Motor Vehicle Door" (January 19, 2017) Korean Patent Registration KR 10-1920440 "Self-Inductive Force Sensor Module for 3D Touch Implementation" (November 14, 2018) Korean Patent Registration KR 10-1954368 "Mutual Inductive Force Sensor Module for 3D Touch Implementation" (February 26, 2019)

The prior art is to improve the sensitivity of the sensor through the arrangement of parts and elements, selection of parts or materials, or by combining an inductive sensor and another sensor to share and sense the touch force and the touch position, or to detect a plurality of inductive sensors. These are technologies that implement and track sensing information of inductive sensors to recognize user gesture patterns.

In addition, the prior arts vary the frequency of the input electrical signal applied to the resonant circuit, scan the size of the output electrical signal formed in the resonant circuit in response to the input electrical signal, and calculate the frequency in the case of having the maximum size as the resonant frequency. Take the composition. For this reason, the prior art has an error as much as the resolution of the variable frequency of the input electrical signal, is an indirect method of calculating the resonant frequency by detecting the size of the electrical signal, and the accuracy is low, and the frequency of the input electrical signal must be varied. There is a problem that it takes a considerable amount of time.

In addition, the prior art detects the magnitude of the electric signal and calculates the resonant frequency and inductance, so it is difficult to make precise measurements.For this reason, it is only possible to determine whether or not the inductance change exceeds a certain threshold, and quantitatively analyze the change in inductance. It doesn't provide as much accuracy as possible.

The present invention was derived in order to solve the problems encountered in the prior art, and the hardware cost is reduced by using only the inductive touch sensor, and even when only the inductive touch sensor is used, the touch position and the touch force can be accurately detected. It is an object of the present invention to provide an inductive force sensor and a method of operation thereof.

In addition, the present invention detects a change in inductance with only a single measurement without frequency fluctuation or input of different frequency components, so that even in the case of a multi-channel inductive force sensor, the touch position and touch force are quickly detected, and the user's intention is recognized. It is an object of the present invention to provide an inductive force sensor capable of and an operation method thereof.

The present invention not only uses an inductive touch sensor, but also does not require fluctuations in frequency or input of different frequency components, thereby reducing power consumption required to detect touch position and touch force, and multi-channel inductive force sensor An object of the present invention is to provide an inductive force sensor and a method of operating the same that can greatly reduce power consumption even in the case of

An object of the present invention is to propose a circuit and an operating method capable of effectively detecting a shift in a resonant frequency. In addition, since the inductive force sensor according to the present invention does not require a process of varying the frequency of an input electrical signal, the object of the present invention is to shorten the sensing time of the touch position and the touch force.

The inductive force sensor according to the present invention aims to shorten a sensing time and reduce power consumption during sensing by simultaneously recognizing a touch position and a touch force with only an inductive touch sensor without a capacitive sensor.

The present invention is a configuration derived to achieve the above object, the inductive force sensor according to an embodiment of the present invention is exposed to an external force in the Z-axis direction, the Z-axis direction by the external force in the Z-axis direction A first part elastically deformable along the line; An inductive coil formed on a substrate spaced apart from the first component; A first resonant circuit coupled to the inductive coil and having a first resonant frequency resulting from a first inductance formed in the inductive coil based on the displacement of the first component with respect to the inductive coil; A first oscillator for applying a first AC signal to the first resonance circuit; A reference resonant circuit having the same impedance as a predetermined first state among states that the first resonant circuit may have; A reference oscillator having the same characteristics as the first oscillator and applying a reference AC signal to the reference resonance circuit; And receiving a first electrical signal formed in the first resonant circuit, receiving a reference electrical signal formed in the reference resonant circuit, and receiving the first resonant frequency of the first electrical signal and a reference resonance of the reference electrical signal. And a determination circuit that determines the displacement of the first component and the external force in the Z-axis direction based on the frequency.

The determination circuit of the inductive force sensor according to an embodiment of the present invention includes the reference resonance frequency and the first reference electrical signal formed in the reference resonance circuit under the influence of the reference AC signal applied to the reference resonance circuit. The difference between the resonance frequencies is detected, and based on the difference between the reference resonance frequency and the first resonance frequency, the degree to which the first resonance circuit deviates from the first state, and the first component moves with respect to the inductive coil. It is possible to obtain quantified sensing information about the relative displacement and the external force in the Z-axis direction.

In the determination circuit of the inductive force sensor according to an embodiment of the present invention, if the difference between the reference resonant frequency and the first resonant frequency is greater than or equal to a first threshold value, the first resonant frequency is regarded as causing a significant change, and the Z It can be determined that the external force in the axial direction is input.

The inductive coil of the inductive force sensor according to an embodiment of the present invention may be formed by overlapping a plurality of unit coil windings in a concentric structure.

The inductive coil of the inductive force sensor according to another embodiment of the present invention is composed of a set of a plurality of unit coil windings, and the plurality of unit coil windings are arranged so as to be spaced apart from each other as they move away from a specific position. I can.

At this time, the determination circuit of the inductive force sensor according to another embodiment of the present invention is based on a change pattern of the difference between the reference resonant frequency and the first resonant frequency appearing in the time domain, in the region covered by the inductive coil. It is possible to recognize quantified sensing information about the external force in the Z-axis direction and a user gesture intended by the external force in the Z-axis direction.

The determination circuit of the inductive force sensor according to an embodiment of the present invention includes an operator for obtaining a difference between the first resonance frequency and the reference resonance frequency; A low pass filter connected to the output terminal of the operator to remove a high frequency component; And digitally counting the frequency of the differential frequency component signal corresponding to the difference between the first resonance frequency and the reference resonance frequency by being connected to the output terminal of the low pass filter (outputting a digitized value proportional to the frequency of the differential frequency component signal) It may include a) time-to-digital converter (Time-to-Digital Converter).

The determination circuit of the inductive force sensor according to an embodiment of the present invention is based on a difference between the first resonant frequency and the reference resonant frequency while the first resonant circuit is forcibly adjusted externally so that it is in the first state. Thus, the calibration process can be performed.

The inductive force sensor according to an embodiment of the present invention includes a plurality of individual regions that are exposed to an external force in the Z-axis direction and elastically deformable along the Z-axis direction by the external force in the Z-axis direction. 2 parts; A plurality of inductive coils formed on a substrate spaced apart from the second component, corresponding to each of the plurality of individual regions, and disposed to face each of the plurality of individual regions; A first inductive coil coupled to a first inductive coil among the plurality of inductive coils and formed in the first inductive coil based on a first displacement of the individual regions in the second component with respect to the first inductive coil. A first channel resonance circuit having a first resonance frequency due to inductance; A first oscillator for applying a first AC signal to the first channel resonance circuit; A second inductive coil coupled to a second inductive coil among the plurality of inductive coils and formed in the second inductive coil based on a second displacement of the individual regions in the second component with respect to the second inductive coil A second channel resonant circuit having a second resonant frequency due to inductance; A second oscillator for applying a second AC signal to the second channel resonance circuit; A reference resonance circuit having the same impedance as a predetermined first state among states that the first channel resonance circuit can have and a second predetermined state among states that the second channel resonance circuit can have; A reference oscillator having the same characteristics as the first oscillator and the second oscillator and applying a reference AC signal to the reference resonant circuit; And a first electrical signal formed in the first channel resonance circuit, a second electrical signal formed in the second channel resonance circuit, and a reference electrical signal formed in the reference resonance circuit. The first displacement, the second displacement, and the external force in the Z-axis direction are input based on the first resonance frequency, the second resonance frequency of the second electrical signal, and the reference resonance frequency of the reference electrical signal. And a determination circuit for determining the position and the external force.

The determination circuit of the inductive force sensor according to an embodiment of the present invention includes the reference resonance frequency and the first reference electrical signal formed in the reference resonance circuit under the influence of the reference AC signal applied to the reference resonance circuit. Detecting a difference between resonant frequencies, and based on the difference between the reference resonant frequency and the first resonant frequency, the degree to which the first channel resonant circuit deviates from the first state, and the first of the individual regions in the second component Acquires displacement and quantified sensing information about the external force in the Z-axis direction appearing in a first individual region corresponding to the first inductive coil, and detects a difference between the reference resonance frequency and the second resonance frequency, , A degree that the second channel resonance circuit deviates from the second state based on a difference between the reference resonance frequency and the second resonance frequency, the second displacement of the individual regions in the second component, and the second inductance. It is possible to obtain quantified sensing information about the external force in the Z-axis direction appearing in a second individual region corresponding to the Tv coil.

In the determination circuit of the inductive force sensor according to an embodiment of the present invention, at least one or more of the difference between the reference resonance frequency and the first resonance frequency, or the difference between the reference resonance frequency and the second resonance frequency is a first threshold. If the value is greater than or equal to the value, at least one of the first resonance frequency and the second resonance frequency may be regarded as causing a significant change, and it may be determined that the external force in the Z-axis direction is input.

The determination circuit of the inductive force sensor according to an embodiment of the present invention includes a first change pattern of a difference between the reference resonance frequency and the first resonance frequency in a time domain, and the reference resonance frequency and the second in a time domain. Based on the second change pattern of the difference in the resonance frequency, the quantified sensing information about the external force in the Z-axis direction in the first area covered by the first inductive coil, the second inductive coil covered by the second inductive coil In area 2, quantified sensing information about the external force in the Z-axis direction and a user gesture intended by the external force in the Z-axis direction may be recognized.

The determination circuit of the inductive force sensor according to an embodiment of the present invention is based on the difference between the reference resonance frequency and the first resonance frequency, and the difference between the reference resonance frequency and the second resonance frequency, Quantified sensing information on the external force in the Z-axis direction in a first area covered by the TV coil, and quantified sensing information on the external force in the Z-axis direction in a second area covered by the second inductive coil Is extracted, and it is possible to determine whether the external force in the Z-axis direction is an input intended by the user.

The determination circuit of the inductive force sensor according to an embodiment of the present invention includes an operator for multiplying the first resonance frequency and the reference resonance frequency, and multiplying the second resonance frequency and the reference resonance frequency; A low pass filter connected to the output terminal of the operator to remove a high frequency component; And digitally counting a frequency of a first differential frequency component signal that is connected to the output terminal of the low-pass filter and corresponding to a difference between the first resonance frequency and the reference resonance frequency, and the difference between the second resonance frequency and the reference resonance frequency. It may include a time-to-digital converter (Time-to-Digital Converter) digitally counting the frequency of the second differential frequency component signal corresponding to.

In the method of operating the inductive force sensor according to an embodiment of the present invention, a first oscillator is coupled to the inductive coil and formed in the inductive coil based on the displacement of the first component with respect to the inductive coil. Applying a first AC signal to a first resonant circuit having a first resonant frequency due to the first inductance; Applying, by a reference oscillator having the same characteristics as the first oscillator, a reference AC signal to a reference resonant circuit having the same impedance as a predetermined first state among states that the first resonant circuit may have; Receiving, by a determination circuit, a first electric signal formed in the first resonant circuit under the influence of the first AC signal; Receiving, by the determination circuit, a reference electric signal formed in the reference resonance circuit; And determining, by the determination circuit, the displacement of the first component and the external force in the Z-axis direction based on the first resonant frequency of the first electrical signal and the reference resonant frequency of the reference electrical signal.

In this case, the determining of the external force in the Z-axis direction by the determination circuit includes: detecting a difference between the reference resonance frequency and the first resonance frequency; And a degree that the first resonant circuit deviates from the first state based on a difference between the reference resonant frequency and the first resonant frequency, a relative displacement of the first component moving with respect to the inductive coil, and the Z-axis. It may include the step of obtaining quantified sensing information about the external force of the direction.

In the method of operating the inductive force sensor according to an embodiment of the present invention, an area covered by the inductive coil is based on a pattern of a difference between the reference resonance frequency and the first resonance frequency appearing in the time domain by the determination circuit. The method may further include recognizing the quantified sensing information of the external force in the Z-axis direction and a user gesture intended by the external force in the Z-axis direction.

In the method of operating an inductive force sensor according to an embodiment of the present invention, a first oscillator is coupled to a first inductive coil among the plurality of inductive coils, and the second component for the first inductive coil is Applying a first AC signal to a first channel resonance circuit having a first resonance frequency due to a first inductance formed in the first inductive coil based on the first displacement of the individual regions; The second oscillator is coupled to a second inductive coil among the plurality of inductive coils, and the second inductive coil is based on a second displacement of the individual regions in the second component with respect to the second inductive coil. Applying a second AC signal to a second channel resonance circuit having a second resonance frequency caused by a second inductance formed in the second inductance; A reference oscillator having the same characteristics as the first oscillator and the second oscillator may have a predetermined first state among states that the first channel resonance circuit may have and a state that the second channel resonance circuit may have. Applying a reference AC signal to a reference resonant circuit having the same impedance as the second state; Receiving, by a determination circuit, a first electric signal formed in the first channel resonance circuit under the influence of the first AC signal; Receiving, by a determination circuit, a second electric signal formed in the second channel resonance circuit under the influence of the second AC signal; Receiving, by the determination circuit, a reference electric signal formed in the reference resonance circuit; And the determination circuit comprises the first displacement and the second displacement based on the first resonance frequency of the first electric signal, the second resonance frequency of the second electric signal, and the reference resonance frequency of the reference electric signal. And determining the position where the external force in the Z-axis direction is input and the external force.

At this time, the determining, by the determination circuit, determining the position at which the external force in the Z-axis direction is input and the external force includes: detecting a difference between the reference resonance frequency and the first resonance frequency; Detecting a difference between the reference resonance frequency and the second resonance frequency; Based on the difference between the reference resonant frequency and the first resonant frequency, the degree to which the first resonant circuit deviates from the first state, the first displacement of the individual regions in the second component, and the first inductive coil Acquiring quantified sensing information about the external force in the Z-axis direction appearing in a first individual region corresponding to a; And a degree that the second resonance circuit deviates from the second state based on the difference between the reference resonance frequency and the second resonance frequency, the second displacement of the individual regions in the second component, and the second inductive. The method may further include obtaining quantified sensing information about the external force in the Z-axis direction appearing in a second individual region corresponding to the coil.

According to the present invention, it is possible to implement an inductive touch force sensor using only the inductive sensor, thereby reducing hardware cost.

According to the present invention, even when an inductive touch force sensor is implemented using only the inductive sensor, a touch position, a touch force, a touch pattern, and a gesture can be precisely sensed. In this case, the touch position and/or the touch force may be simultaneously indicated by one output value.

According to the present invention, since a change in inductance can be detected with a single measurement without scanning a frequency component, power consumption and sensing time can be shortened.

According to the present invention, since the change in inductance can be accurately detected with a single measurement for each sensor without scanning the frequency component, even if the inductive sensor array or the inductive sensor matrix is formed and operated, it is relatively free from the constraints of power consumption and sensing time. It is possible to accurately determine various touch patterns, touch gestures, and touch conditions using an array or matrix.

According to an embodiment of the present invention, a change in a time domain may be detected and a gesture may be recognized using an inductive sensor of a single channel or a single coil.

According to an embodiment of the present invention, it is possible to verify whether there is an error in the sensing result by combining sensing results simultaneously detected for a plurality of channels or coils. In consideration of a sensing result detected at the same time for a plurality of coils and a positional relationship between regions covered by the coils, it is possible to verify whether a touch force derived from the sensing result is due to a user's intention or an error.

Since the prior art detects the amplitude of the resonance signal or the analog AC signal, it is only possible to detect whether the detected result exceeds a predetermined threshold. However, according to the present invention, since the difference in the resonance frequency of the differential signal is calculated and digitally counted, quantified sensing information can be obtained, and a change in the touch force in time-space can be accurately detected using this.

1 is a diagram showing an inductive force sensor according to an embodiment of the present invention.
2 is a diagram illustrating an inductive force sensor according to an embodiment of the present invention.
3 is a diagram illustrating an inductive force sensor and an operating method thereof according to an embodiment of the present invention.
4 is a diagram illustrating an inductive force sensor and a method of operating the same according to an embodiment of the present invention.
5 is a diagram showing a coil structure of an inductive force sensor according to an embodiment of the present invention.
6 is a diagram showing a coil structure of an inductive force sensor according to an embodiment of the present invention.
7 is a diagram illustrating a circuit and an operating method of an inductive force sensor according to an embodiment of the present invention.
8 is a diagram showing a circuit and an operating method of an inductive force sensor according to an embodiment of the present invention.
9 is an operation flowchart illustrating a method of operating an inductive force sensor according to an embodiment of the present invention.
10 is a flowchart illustrating a method of operating an inductive force sensor according to an embodiment of the present invention.
11 is a diagram illustrating an inductive force sensor according to an embodiment of the present invention.
12 is a diagram illustrating an inductive force sensor according to an embodiment of the present invention.

In addition to the above objects, other objects and features of the present invention will become apparent through the description of the embodiments with reference to the accompanying drawings. A preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, when it is determined that a detailed description of a related known configuration or function may obscure the subject matter of the present invention, a detailed description thereof will be omitted. Hereinafter, an inductive force sensor according to an embodiment of the present invention and a method of operating the same will be described in detail with reference to FIGS. 1 to 10.

1 is a diagram illustrating an inductive force sensor 100 according to an embodiment of the present invention. FIG. 1 shows an inductive force sensor 100 assuming a single button/channel/coil.

Referring to Figure 1, the inductive force sensor 100 according to an embodiment of the present invention is exposed to an external force 150 in the Z-axis direction, and the Z-axis direction by the external force 150 in the Z-axis direction. A first part 130 elastically deformable along the line; A target layer 140 disposed to be movable along the Z-axis direction based on the deformation of the first part 130; An inductive coil 112 formed on the substrate 110 disposed to be spaced apart from the target layer 140; And a spacer layer 160 that supports the first component 130 and separates the inductive force sensor 100 from other sensors or sensing channels.

The inductive force sensor 100 shown in FIG. 1 forms a single channel. Depending on the embodiment, an array or matrix may be implemented by arranging a plurality of inductive force sensors 100 as shown in FIG. 1 in parallel.

When the first part 130 is elastically deformed by the external force 150 applied along the Z-axis direction, the target layer 140 may move along the Z-axis direction according to the degree of deformation of the first part 130. have. At this time, the inductive coil 112 and the target layer 140 formed on the printed circuit board 110 are inductively coupled.

In this case, a material having an elastic restoring force, for example, a foam may be disposed between the target layer 140 and the inductive coil 112. When the external force 150 is applied, the target layer 140 approaches the inductive coil 112, and accordingly, the inductance formed in the inductive coil 112 inductively coupled to the target layer 140 changes.

When the external force 150 is removed, the target layer 140 returns to the position before deformation by the elastic restoring force of the foam. That is, the change in inductance appears only while the external force 150 is applied, and when this is detected, the external force 150 in the Z-axis direction can be sensed.

The distance at which the target layer 140 is separated from the inductive coil 112 in the first state in which the external force 150 is not applied is denoted d0, and the target layer 140 is inductive when the external force 150 is applied. If the distance from the coil 112 is d, the displacement Δd = |d-d0| causes a change in inductance formed in the inductive coil 112 inductively coupled to the target layer 140. Therefore, when a change in inductance is detected, the displacement Δd can be detected, and the magnitude of the external force 150 can be quantified.

In this specification, for convenience of description, a unit for sensing the external force 150 of one inductive coil 112 and a region covered by the inductive coil 112 is referred to as a channel. The target layer 140 may be separated from other channels and disposed for each channel as illustrated in FIG. 1, or may be commonly disposed in a group consisting of a plurality of channels as illustrated in FIG. 2 to be described later. In FIG. 1, a target layer 140 is disposed for each individual channel, and an embodiment in which each channel is physically separated from other channels by a spacer layer 160 is illustrated.

The target layer 140 may be a non-magnetic metal or a magnetic metal. As for the target layer 140, a conductive conductor is preferred so that an Eddy current can be formed. Depending on whether the target layer 140 has magnetism, it may be determined whether the inductance increases or decreases when the external force 150 is applied. A material in which variables such as displacement versus inductance detection sensitivity are optimized based on the magnetic/nonmagnetic of the target layer 140 and the hardware design of the channel may be selected as the target layer 140.

The inductive coil 112 of the inductive force sensor 100 according to an embodiment of the present invention may be formed by overlapping a plurality of unit coil windings in a concentric structure.

The target layer 140 is moved in the Z-axis direction by the external force 150, but the target layer 140 may be implemented to maintain a state parallel to the inductive coil 112, but according to an embodiment of the present invention The target layer 140 may move while forming a slight inclination with the inductive coil 112 according to a position on the XY plane where the external force 150 is concentrated while the target layer 140 is not parallel to the inductive coil 112. In this case, in the prior art, it becomes a factor of measurement error, making it difficult to accurately sense the touch force, but in the present invention, since the change in inductance can be accurately quantified based on the differential detection of the inductance, it is not necessary to accurately detect the touch force. Of course, depending on the embodiment, the position on the XY plane where the external force 150 is concentrated may be detected in detail. This embodiment will be described later with reference to FIGS. 5 and 6.

Most wearable devices use mechanical buttons that require cutouts in the enclosure forming the boundary with the outside, so it is difficult to seal the device, and the IP rating, which means the dustproof and waterproof function, may be lowered. Mechanical buttons also use moving parts, metallic contacts, and gaskets, which have long-term reliability issues, cause cost increases, and are less resistant to environmental factors. It has a low problem.

If a cut out free enclosure can be implemented, a high IP rating can be implemented, and a wearable device having a higher IP rating can be used for various purposes that have not been previously utilized. If gasket-less and no moving parts are used, the wearable device can be physically more robust and embedded in wearable elements, e.g. gloves. It could be, and it could be used under water.

In order to achieve such a high IP rating, there is an attempt to utilize an electromagnetic device that recognizes a touch pressure instead of a mechanical button. As one of these attempts, there is a movement to use a capacitive proximity sensor, but the capacitive proximity sensor is affected by the electric field and is affected by whether or not the surrounding is energized, so it cannot be used underwater, and the range of application is limited. .

In place of the capacitive proximity sensor, an inductive touch sensor has been proposed that measures inductance by causing a change in a magnetic field in a way to recognize a touch pressure by measuring a change in impedance. The fact that inductive sensors are not sensitive to external disturbances compared to capacitive sensors is a reason for the spread of inductive sensors.

The method of implementing an inductive force sensor using an inductive touch sensor is described in the previously mentioned prior documents, for example, US Patent Publication No. US 2018/0180450 "Inductive Touch Input", US Patent Publication US 2017/0016255 "Device for Detecting a User's Intention to Lock or Unlock a Motor Vehicle Door", or Korean Patent No. KR 10-1920440 "Self-inductive force sensor module for 3D touch implementation".

On the other hand, compared to a capacitive sensor capable of precise detection using an electrical signal, an inductive sensor that must use a change in a magnetic field is not easy to increase detection accuracy. The inductive sensing technology of the prior literature is also mainly used for detecting a specific event to the extent that it detects whether it is above a certain threshold rather than precise measurement.

The configuration of FIG. 1 and the prior documents may be included as part of the configuration of the present invention, and by combining with the new configurations of the present invention to be mentioned later, the unique effects of the present invention will be achieved. In particular, in combination with recent mobile devices, smart devices, virtual reality, and augmented reality, the user interface aims to recognize a precise touch force, accurately recognize user gestures, and understand the user's intention. The present invention improves the inductive sensing of the prior art to precisely measure and quantify the change in the touch force, the displacement of the target due to the touch force, and the change in inductance, thereby proposing a technology to understand the user's intention and accurately recognize the user gesture. do.

According to one of the embodiments of the present invention, when a separate coil is not disposed on the target layer 140, the eddy current of the inductive coil 112 and the target layer 140 responds to each other in a self-inductive method. The displacement of the target layer 140 may be measured.

According to another embodiment of the present invention, a mutual inductive coil (not shown) is disposed on the target layer 140, the mutual inductive coil of the target layer 140 and the inductive coil 112 on the substrate 110 In response to this, the displacement of the target layer 140 may be measured in a mutual inductive method.

2 is a diagram showing an inductive force sensor 200 according to an embodiment of the present invention.

2, the inductive force sensor 200 according to an embodiment of the present invention is exposed to an external force in the Z-axis direction, and is elastically deformed along the Z-axis direction by the external force in the Z-axis direction. A second part 230 comprising a plurality of possible individual regions 232; A target layer 240 disposed to be movable along the Z-axis direction when at least one of the plurality of individual regions 232 of the second component 230 is deformed; And formed on the substrate 210 spaced apart from the target layer 240, corresponding to each of the plurality of individual regions 232, and disposed to face each of the plurality of individual regions 232 It includes a plurality of inductive coils 212.

The second component 230 may be made of a material that can be elastically deformable, and the individual regions 232 may be made of the same material as the remaining regions except for the individual regions 232 of the second component 230. That is, since the second component 230 may surround the entire area of the inductive force sensor 200 illustrated in FIG. 2 with a single shell, the IP rating of the inductive force sensor 200 may be increased. For example, assuming a smart watch in which the individual areas 232 have independent numbers as shown in FIG. 2, the individual areas 232 exposed by the smart watch are surrounded by a single shell, so excellent dustproof waterproof performance is achieved. It is expected. Since the individual regions 232 are arranged corresponding to the holes of the spacer layer 260, when an external force is applied to one or more of the individual regions 232, the corresponding region is elastic based on the elasticity of the second component 230. Can be sexually transformed.

According to an embodiment of the present invention, the inductive force sensor 200 of FIG. 2 may be located on the bezel, side, or rear of the mobile device, and the individual regions 232 have a small size so that they are not identified by the user. It can also be placed in a dense manner. In this case, the inductive force sensor 200 may be used as a means for determining whether the user is holding the corresponding device or whether a predetermined user gesture is input to the inductive force sensor 200 area of the corresponding device.

Unlike in FIG. 1, in FIG. 2, the target layer 240 is commonly disposed in a module including a plurality of individual regions 232 and inductive coils 212. Assuming that the spacer layer 260 also has a weak elastic restoring force, the target layer 240 is distorted in the XYZ space and asymmetrical to the inductive coils 212 according to which of the individual regions 232 the touch force is applied. Will provide a natural displacement. For example, the distribution of inductances formed in the inductive coils 212 when the 1st button is pressed and when the 6th button is pressed will be different, and this pattern is tested beforehand and then the inductive force sensor 200 ) Of the controller can store it. The inductive force sensor 200 may extract the input intended by the user by comparing the distribution of inductances displayed in the plurality of inductive coils 212 and the inductance distribution pattern stored in advance when an external force is actually applied. .

In the prior art, it is not easy to simultaneously detect the inductance of a plurality of channels. In the present invention, the inductance of a plurality of channels can be detected at the same time without substantially time difference, and since quantified data can be obtained, the spatial distribution of the touch force within the area covered by the inductance force sensor 200 can be obtained. You can understand your intentions.

According to an embodiment of the present invention, when a separate coil is not disposed on the target layer 240, the inductive coil 212 and the eddy current of the target layer 240 correspond to each other in a self-inductive method. The displacement of the target layer 240 may be measured.

According to another embodiment of the present invention, a mutual inductive coil (not shown) is disposed on the target layer 240, and the mutual inductive coil of the target layer 240 and the inductive coil 212 on the substrate 210 In response to this, the displacement of the target layer 240 can be measured in a mutual inductive method.

3 is a diagram illustrating an inductive force sensor 300 and an operating method thereof according to an embodiment of the present invention.

Referring to FIG. 3, as a set consisting of a set of a plurality of coils 312 in the inductive force sensor 300, one module 310a is shown.

In the module 310a, the user's touch force changes temporally and spatially within the area covered by the module 310a by tracking the spatial distribution of the inductance on the XY plane on the XY plane in the module 310a. You can trace the pattern.

The inductive force sensor 300 tracks the spatial distribution of the external force in the Z-axis direction on the XY plane recognized in individual regions covered by each of the plurality of coils 312 in the time domain, so that the center of the external force is the XY plane. It is possible to analyze the direction and speed of movement in the time domain. According to this, the inductive force sensor 300 is a pattern of a touch force applied by a user in the area covered by the inductive force sensor 300, for example, tapping, slide/scroll/swipe, zoom in/zoom out. User gestures, such as doing, can be recognized as an inductive sensing technique.

The inductive force sensor 300 combines the X-axis movement information in which the center position of the touch force moves along the X-axis direction and the Y-axis movement information in which the center position of the touch force moves along the Y-axis direction. It is also possible to derive movement information on the XY plane where the center position of the touch force moves. In another embodiment, the inductive force sensor 300 includes gesture information in which the center position of the touch force moves on the XY plane directly from the variation pattern of the touch force obtained in individual regions covered by each of the plurality of coils 312 You can also get In addition, since each channel information is obtained independently, the inductive force sensor 300 can recognize the user gesture without confusion even if a user gesture by multi-touch is input within the sensing area covered by the plurality of coils 312. have.

4 is a diagram illustrating an inductive force sensor 400 and an operating method thereof according to an embodiment of the present invention.

Referring to FIG. 4, as a set consisting of a set of a plurality of coils 412 in the inductive force sensor 400, one module 410a is shown.

For example, if the module 410a is an interface that is displayed externally by numbering individual areas, as shown in FIG. 4, the external force is difficult to specify the individual areas within the range 452 into which the external force is input. If this is measured equally, it is not intended that the user touches a specific number area, but it can be measured that the device is simply holding the device in hand or pressure is applied by other factors from the outside, thereby preventing malfunction of the device.

To this end, it is necessary to detect the inductance distribution pattern of the individual regions included in the module 410a and the plurality of coils 412 at substantially the same time. In the present invention, the inductance is determined based on the differential resonance signal with the reference inductance. This is achieved by detecting the change and the touch force of the individual regions associated with each of the coils 412. Related matters will be described later in the description of FIGS. 7 and 8.

5 is a diagram showing a coil structure of an inductive force sensor 500 according to an embodiment of the present invention.

5, the inductive channel coil 512 of the inductive force sensor 500 according to an embodiment of the present invention is made up of a set of a plurality of unit coil windings, and the plurality of unit coil windings are at a specific position. It can have a structure that is arranged so as to be spaced farther apart from each other as the distance increases.

The target layer 140 shown in FIG. 1 causes a displacement in the Z-axis direction when an external force in the Z-axis direction is applied. In this case, the target layer 140 must be able to maintain a state parallel to the inductive coil 512 no. Accordingly, the target layer 140 may cause displacement in the Z-axis direction while being distorted in the XYZ space. In this case, the displacement of the target layer 140 may differ according to a position on the XY plane where an external force is concentrated in the channel region 514 covered by one inductive channel coil 512. At this time, as shown in FIG. 5, if the coil structure of the inductive coil 512 is a structure in which the distance between the unit coil windings in the inductive coil 512 increases or becomes closer as the coil structure of the inductive coil 512 moves away from the center of the inductive force sensor 500 The inductance change detected by the inductive coil 512 will vary according to the position on the XY plane where the external force is concentrated in the channel region 514. Therefore, by comparing the quantification pattern of the inductance previously tested and stored with the quantification pattern of the actually measured inductance, the position on the XY plane where the external force is concentrated in the channel region 514 can be identified.

At this time, by identifying and tracking the position on the XY plane where the external force is concentrated in the channel region 514 in the time domain, even a single channel inductive force sensor can recognize a user gesture of tapping or sliding/scrolling/swiping.

In FIG. 5, the structure of each inductive coil 512 is asymmetric, but when one module is formed by being formed as a set of inductive coils 512, the module is an inductive force sensor 500 to have symmetry. ) Can be implemented.

6 is a diagram showing a coil structure of an inductive force sensor 600 according to an embodiment of the present invention.

6, the inductive channel coil 612 of the inductive force sensor 600 according to an embodiment of the present invention is made of a set of a plurality of unit coil windings, and the plurality of unit coil windings are at a specific position. It can have a structure that is arranged so as to be spaced apart from each other as the distance from the

At this time, the position on the XY plane where the external force is concentrated in the channel region 614 covered by one inductive channel coil 612 can be identified, and when tracking the position on the XY plane where the external force is concentrated in the time domain It is as described above with reference to FIG. 5 that the user gesture can be recognized even within the channel region 614.

In FIG. 6, when the structure of each inductive coil 612 is asymmetric and is formed as a set of inductive coils 612 to form one module, the module maintains asymmetry, but the regularity is inductive force. The sensor 600 may be implemented.

7 is a diagram illustrating a circuit and an operating method of the inductive force sensor 700 according to an embodiment of the present invention.

Referring to the inductive force sensor 100 of FIG. 1 and the circuit of FIG. 7 together according to an embodiment of the present invention, the inductive force sensors 100 and 700 are combined with the inductive coils 112 and 712 and the Based on the displacement of the target layer 140, 740 with respect to the inductive coils 112 and 712, the first resonant frequency ω1 is caused by the first inductance formed in the inductive coils 112 and 712. 1 resonant circuit 720 is included.

In this case, the inductive force sensors 100 and 700 according to an embodiment of the present invention include a first oscillator 722 for applying a first AC signal to the first resonant circuit 720; A reference resonant circuit (not shown in FIG. 7) having the same impedance as a first predetermined state (a state in which no external forces 150 and 750 are applied is preferred) among states that the first resonant circuit 720 may have. ); A reference oscillator (not shown in FIG. 7) that has the same characteristics as the first oscillator 722 and applies a reference AC signal to the reference resonant circuit; And receiving a first electrical signal formed in the first resonant circuit 720, receiving a reference electrical signal formed in the reference resonant circuit, and receiving the first resonant frequency (ω1) of the first electrical signal and the The displacement Δd of the target layers 140 and 740 based on the reference resonance frequency (ω_ref) of the reference electrical signal Δd = |d-d0| And a determination circuit 770 that determines the external forces 150 and 750 in the Z-axis direction.

The determination circuit 770 of the inductive force sensors 100 and 700 according to an exemplary embodiment of the present invention includes the reference electric signal formed in the reference resonance circuit under the influence of the reference AC signal applied to the reference resonance circuit. The first resonant circuit detects a difference between the reference resonant frequency ω_ref and the first resonant frequency ω1, and based on the difference between the reference resonant frequency ω_ref and the first resonant frequency ω1 The degree of deviation from the first state, the relative displacement Δd = |d-d0| that the target layers 140 and 740 moved with respect to the inductive coils 112 and 712, and the external force 150 in the Z-axis direction , 750) quantified detection information may be obtained.

The first resonant circuit 720 shown in FIG. 7 represents an equivalent circuit, and does not necessarily include a lumped RLC element. For example, the capacitance C 716 and the resistor R 718 may be independent devices or may represent parasitic components. In addition, even when the first resonant circuit 720 is implemented by using an independent element, the arrangement of the elements does not necessarily follow FIG. 7 and it is sufficient if the arrangement of the elements can correspond to the first resonant circuit 720 equivalently.

The determination circuit 770 of the inductive force sensor 100 and 700 according to an exemplary embodiment of the present invention comprises the reference resonance frequency ω_ref and the first resonance frequency ω1 when the difference between the reference resonance frequency ω_ref and the first resonance frequency ω1 is greater than or equal to a first threshold value. It may be determined that the external force 150 in the Z-axis direction is input by considering that the first resonance frequency ω1 has caused a significant change. That is, when the change in the first resonance frequency ω1 is detected due to noise, unintended motion, unintentional contact, and unintentional vibration, but below the first threshold, the first resonance frequency ω1 makes a significant change. It can be regarded as not causing it.

The determination circuit 770 of the inductive force sensors 100 and 700 according to an embodiment of the present invention is in a state that is forcibly adjusted from the outside so that the first resonance circuit 720 is in the first state (external A state in which the pressures 150 and 750 are not applied is preferred.) A calibration process may be performed based on a difference between the first resonance frequency ω1 and the reference resonance frequency ω_ref.

The determination circuit 770 may perform a calibration process. The determination circuit 770 may perform a calibration process in a state in which external forces 150 and 750 are not applied. At this time, the first resonance circuit 720 or the reference resonance circuit may be adjusted so that a difference between the first resonance frequency ω1 and the reference resonance frequency ω_ref becomes zero through the calibration process. In addition, the difference between the first resonant frequency (ω1) and the reference resonant frequency (ω_ref) detected in the first state in which no external force (150, 750) is applied through the calibration process is stored in a separate memory or storage. It may be processed as offset information in the inductive force sensing process. Adjustment of the difference between the first resonant frequency (ω1) and the reference resonant frequency (ω_ref) after calibration is performed by adjusting the value of the variable resistor R'that can be added to the first resonant circuit 720. Can be executed by

In general, the inductive sensing technology known to date is to measure the change in impedance after sequentially inputting a plurality of frequency signals through a variable frequency scan. This method is a prerequisite for accurately detecting and comparing the size of the signal. There was this. However, it is very difficult to accurately detect the magnitude of signals despite noise in a general inductive sensor.

In the present invention, instead of using the amplitude of the signals as the main detection object, the change of the resonance frequency is the main detection object. Also, a means of applying an AC signal of the same frequency without adopting a method such as variable frequency scanning is sufficient. Can be achieved. Therefore, using this method, the present invention can quickly detect and quantify the change in inductance at the time point. A real-time change of the first resonant frequency ω1 may be detected regardless of the amplitude of the resonant signal by the method of FIG. 8 to be described later. In addition, since the first resonant frequency (ω1) is not detected by an indirect method, but the value of the frequency is directly detected, it is easy to digitize using this, and the change in inductance and touch force are precisely controlled by using the digitized value. It has the advantage of being able to detect it. Also, since there is no process such as variable frequency scanning, the sensing process is fast and power consumption is low. Since the inductive sensing process for one coil and channel is quick and the sensing result is obtained as a digitized value, even when a plurality of channels are implemented, a change in inductance and a change in touch force can be detected substantially simultaneously. When each channel and coil corresponds to a position on the XY plane, the spatial change of the quickly obtained touch force on the XY plane makes it easy to identify whether the touch force is due to the user's intention, error or other cause. To be. In addition, by tracking the spatial change of the touch force on the XY plane in the time domain, it is possible to easily recognize a gesture by the user's intention.

Referring to the inductive force sensor 200 of FIG. 2 and the circuit of FIG. 7 according to another embodiment of the present invention, the inductive force sensors 200 and 700 according to an embodiment of the present invention are Combined with a first inductive coil among the inductive coils 212 and 712 and formed in the first inductive coil based on the first displacement of the target layer 240 and 740 with respect to the first inductive coil. A first channel resonance circuit 720 having a first resonance frequency ω1 due to the first inductance; A first oscillator (722) applying a first AC signal to the first channel resonance circuit (720); The second inductive coil is coupled to a second inductive coil among the plurality of inductive coils 212 and 712 and based on a second displacement of the target layer 240 and 740 with respect to the second inductive coil. A second channel resonant circuit (not shown) having a second resonant frequency (ω2) caused by a second inductance formed in the inductance; A second oscillator (not shown) for applying a second AC signal to the second channel resonance circuit; A reference resonance circuit having the same impedance as a predetermined first state among states that the first channel resonance circuit 720 may have and a second state of the states that the second channel resonance circuit may have; A reference oscillator having the same characteristics as the first oscillator 722 and the second oscillator and applying a reference AC signal to the reference resonance circuit; And a first electrical signal formed in the first channel resonance circuit 720, a second electrical signal formed in the second channel resonance circuit, and a reference electrical signal formed in the reference resonance circuit, and the first The first displacement, the second based on the first resonance frequency (ω1) of the electrical signal, the second resonance frequency (ω2) of the second electrical signal, and the reference resonance frequency (ω_ref) of the reference electrical signal And a determination circuit 770 for determining a displacement and a position at which the external force 750 in the Z-axis direction is input and the external force 750.

The determination circuit 770 of the inductive force sensors 200 and 700 according to an exemplary embodiment of the present invention includes the reference electric signal formed in the reference resonance circuit under the influence of the reference AC signal applied to the reference resonance circuit. Detecting a difference between the reference resonance frequency (ω_ref) and the first resonance frequency (ω1), and based on the difference between the reference resonance frequency (ω_ref) and the first resonance frequency (ω1), the first channel resonance circuit ( 720) deviates from the first state, the first displacement of the targets 240 and 740, and the external force 750 in the Z-axis direction appearing in a first individual region corresponding to the first inductive coil Obtaining the quantified detection information for, detecting a difference between the reference resonance frequency (ω_ref) and the second resonance frequency (ω2), and the difference between the reference resonance frequency (ω_ref) and the second resonance frequency (ω2) Based on the degree to which the second channel resonance circuit deviates from the second state, the second displacement of the targets 240 and 740, and the Z axis appearing in a second individual region corresponding to the second inductive coil Quantified sensing information on the external force 750 in the direction may be obtained.

The determination circuit 770 of the inductive force sensors 200 and 700 according to an exemplary embodiment of the present invention includes a difference between the reference resonance frequency (ω_ref) and the first resonance frequency (ω1), or the reference resonance frequency (ω_ref). ) And at least one of the differences between the second resonance frequency (ω2) and the first threshold value, at least one of the first resonance frequency (ω1) and the second resonance frequency (ω2) has caused a significant change. Considering that, it can be determined that the external force 750 in the Z-axis direction has been input.

Referring to the inductive force sensor 300 of FIG. 3 and the circuit of FIG. 7 according to another embodiment of the present invention together, the determination circuit of the inductive force sensor 300 and 700 according to an embodiment of the present invention ( 770) is a first change pattern of the difference between the reference resonance frequency (ω_ref) and the first resonance frequency (ω1) appearing in the time domain, and the reference resonance frequency (ω_ref) and the second resonance frequency (ω2) appearing in the time domain. ) Based on the second change pattern of the difference, quantified sensing information about the external force 750 in the Z-axis direction in the first area covered by the first inductive coil, and the second inductive coil covers In the second region, the quantified sensing information on the external force 750 in the Z-axis direction and the intended user gesture by the external force 750 in the Z-axis direction may be recognized.

At this time, even if the determination circuit is not allocated for each individual coil 312 of one module 310a and one determination circuit is allocated to one module 310a, the inductance distribution of the individual coils 312 is substantially timed apart. Can be measured without.

Referring to the inductive force sensor 400 of FIG. 4 and the circuit of FIG. 7 according to another embodiment of the present invention, the determination circuit of the inductive force sensor 400 and 700 according to an embodiment of the present invention ( 770) is based on the difference between the reference resonant frequency ω_ref and the first resonant frequency ω1, and the difference between the reference resonant frequency ω_ref and the second resonant frequency ω2, the first inductive Quantified sensing information on the external force 750 in the Z-axis direction in the first area covered by the coil, and the external force 750 in the Z-axis direction in the second area covered by the second inductive coil It is possible to extract the quantified detection information for and determine whether the external force in the Z-axis direction is an input intended by the user.

At this time, even if the determination circuit is not allocated to each individual coil 412 of one module 410a and one determination circuit is allocated to one module 410a, the inductance distribution of the individual coils 412 is substantially timed apart. Can be measured without.

Referring to the inductive force sensor 500 of FIG. 5 and the circuit of FIG. 7 according to another embodiment of the present invention, the determination circuit of the inductive force sensor 500 and 700 according to an embodiment of the present invention ( 770) is the Z-axis in the channel region 514 covered by the inductive coil 512 based on a change pattern of the difference between the reference resonant frequency (ω_ref) and the first resonant frequency (ω1) appearing in the time domain. The quantified sensing information on the external force 750 in the direction and the intended user gesture may be recognized by the external force 750 in the Z-axis direction. That is, even within the single channel region 514, a change in the position of the external force 750 on the XY plane can be recognized, and a change in the position of the external force 750 on the XY plane can be tracked in the time domain to recognize the user's intended gesture. have.

8 is a diagram illustrating a circuit and an operating method of the inductive force sensor 800 according to an embodiment of the present invention.

1 and 8 together, the inductive force sensors 100 and 800 according to an embodiment of the present invention include a first resonance circuit 820, a first oscillator 822, and a reference resonance circuit 820a. , A reference oscillator 822a. Since operations of the first resonance circuit 820, the first oscillator 822, and the reference resonance circuit 820a and the reference oscillator 822a of FIG. 8 are similar to those described in the embodiments of FIG. 7, overlapping descriptions Is omitted.

The determination circuit 870 of the inductive force sensors 100 and 800 according to an embodiment of the present invention includes an operator circuit that calculates a difference between the first resonance frequency ω1 and the reference resonance frequency ω_ref ( 872), a low pass filter 874 connected to the output terminal of the calculator circuit 872 to remove a high frequency component, and an output terminal of the low pass filter 874 to be connected to the first resonance frequency ( Time-to-digital converter (Time to digitally count the frequency of the differential frequency component signal corresponding to the difference between ω1) and the reference resonant frequency (ω_ref) (outputting a digitized value proportional to the frequency of the differential frequency component signal) -to-Digital Converter) 876 may be included.

The operator circuit 872 may immediately obtain a differential frequency component signal by using arithmetic operations (addition, subtraction, and multiplication) between the first electric signal and the reference electric signal. The time-to-digital converter 876 counts the number of pulses of a pulse signal having a differential frequency (or a frequency proportional to the differential frequency) for a certain period of time, or a pulse having a differential frequency (or a frequency proportional to the differential frequency). You can generate a digital count value for the pulse width or period of the signal.

Depending on the embodiment of the determination circuit 870, a sampler and a comparator for the differential frequency component signal may be included. In this case, the sampler and the comparator are sufficiently larger than the first threshold for smooth operation of the determination circuit 870. It can be designed by selecting an operating frequency that is large and sufficiently larger than the operating range of the resonance frequency component corresponding to the displacement to be detected.

At this time, the reference resonance circuit 820a is blocked from external influences and is managed to keep the initial settings.

Referring to the inductive force sensor 200 of FIG. 2 and FIG. 8, which is another embodiment of the present invention, the determination circuit 870 of the inductive force sensor 200 and 800 according to the embodiment of the present invention is described above. A calculator circuit 872 and a calculator circuit 872 that calculates the difference between the first resonance frequency ω1 and the reference resonance frequency ω_ref, and calculates the difference between the second resonance frequency ω2 and the reference resonance frequency ω_ref. ) Is connected to the output terminal of the low pass filter 874 to remove high frequency components, and the first resonance frequency ω1 and the reference resonance frequency ( The frequency of the first differential frequency component signal corresponding to the difference between ω_ref) is digitally counted, and the frequency of the second differential frequency component signal corresponding to the difference between the second resonance frequency (ω2) and the reference resonance frequency (ω_ref) is calculated. A digital counting time-to-digital converter 876 may be included.

When a plurality of inductive coils 212 and channels are added, a resonant circuit may be added one by one corresponding to each inductive coil 212 and channel. Even when a number of inductive coils 212 and channels are added, the reference resonant circuit 820a and the determination circuit 870 need not be added. The determination circuit 870 receives the electrical signals received from each of the plurality of inductive coils 212 and the channels by a time multiplexing technique, and between each of the channel resonance frequencies of the electrical signals of each received channel and the reference resonance frequency (ω_ref). By detecting the difference, inductance of each channel, displacement occurring in each channel, and touch force occurring in each channel can be detected. Although not shown, the inductance of each channel detected by the determination circuit 870, the displacement occurring in each channel, and the touch force data generated in each channel are associated with the channel identification information capable of identifying each channel, and thus the memory or storage Can be stored in.

In embodiments of the present invention, since the differential frequency component between the resonant frequency of each channel and the reference resonant frequency (ω_ref) can be immediately obtained by the determination circuits 770 and 870, the inductance of a plurality of channels substantially simultaneously without time delay, Displacement and touch force can be identified.

In embodiments of the present invention, the determination circuits 770 and 870 may detect the resonance frequency information of each channel independently (without detecting the amplitude) of the electric signal and the reference electric signal of each channel. At this time, depending on the embodiment, a conventional technique for detecting amplitude independently of the resonance frequency is applied in parallel, and two pieces of detection information obtained independently of each other (first detection information based on the detection of the amplitude, the resonance frequency independently of the amplitude The second detection information based on the detection of may be cross-verified.

9 is a flowchart illustrating a method of operating an inductive force sensor according to an embodiment of the present invention.

The operation method of FIG. 9 may be executed in the inductive force sensors 100, 700, and 800 with reference to FIGS. 1, 7, and 8.

In an operating method of the inductive force sensors 100, 700, and 800 according to an embodiment of the present invention, the first oscillators 722 and 822 are coupled to the inductive coils 112 and 712, and the inductive coil 112 , A first resonance circuit having a first resonance frequency (ω1) due to a first inductance formed in the inductive coils 112 and 712 based on the displacement of the targets 140, 740, and 840 with respect to 712 ( Applying a first AC signal to 720 and 820 (S910); The reference oscillator 822a having the same characteristics as the first oscillators 722 and 822 is a reference resonant circuit having the same impedance as a predetermined first state among states that the first resonant circuits 720 and 820 may have Applying a reference AC signal to (820a) (S920); Receiving, by a determination circuit (770, 870), a first electrical signal formed in the first resonance circuit (720, 820) under the influence of the first AC signal (S930); Receiving a reference electrical signal formed in the reference resonance circuit 820a by the determination circuits 770 and 870 (S930); And displacement of the targets 140, 740, 840 based on the first resonant frequency ω1 of the first electric signal and the reference resonant frequency ω_ref of the reference electric signal by the determination circuits 770 and 870 And determining the external forces 150 and 750 in the Z-axis direction (S960).

At this time, the determination circuits 770 and 870 perform step (S940) of detecting a difference between the reference resonance frequency (ω_ref) and the first resonance frequency (ω1), and based on the result of step (S940), the 1 The degree to which the resonance circuits 720 and 820 deviate from the first state, the relative displacement of the targets 140, 740 and 840 with respect to the inductive coils 112 and 712, and the Z-axis direction An operation (S960) of obtaining quantified sensing information about the external forces 150 and 750 may be performed.

At this time, the determination circuits 770 and 870 may determine whether the result of step S940 exceeds the first threshold value and perform step S950 of determining whether a significant change is detected.

In the method of operating the inductive force sensors 500, 700, and 800 according to another embodiment of the present invention, the reference resonance frequency ω_ref and the first resonance frequency appearing in the time domain by the determination circuits 770 and 870 Quantified sensing information about the external force 750 in the Z-axis direction in the channel region 514 covered by the inductive coils 512 and 712 based on the change pattern of the difference of (ω1), and the Z-axis It may further include recognizing a user gesture that is assumed to be intended by the user based on the external force 750 in the direction.

10 is a flowchart illustrating a method of operating an inductive force sensor according to an embodiment of the present invention.

The operating method of FIG. 10 may be executed by the inductive force sensors 200, 700, and 800 with reference to FIGS. 2, 7, and 8 together.

In the method of operating the inductive force sensors 200, 700, and 800 according to an embodiment of the present invention, steps S910 to S930 of FIG. 9 are performed for the first channel, and in particular, the determination circuits 770 and 870 are performed at step S930. Perform. In addition, steps S910 to S930 of FIG. 9 are individually performed for the second channel.

The determination circuit (770, 870) based on the first resonant frequency of the first electrical signal, the second resonant frequency of the second electrical signal, and the reference resonant frequency of the reference electrical signal, the first displacement, the Steps S1020 and S1040 of determining the second displacement and the position at which the external force in the Z-axis direction is input and the external force are performed.

At this time, the determining, by the determination circuit, determining the position at which the external force in the Z-axis direction is input and the external force may include detecting a difference between the reference resonance frequency and the first resonance frequency (S1010); Detecting a difference between the reference resonance frequency and the second resonance frequency (S1030); Based on the difference between the reference resonance frequency and the first resonance frequency, a degree of the first resonance circuit deviating from the first state, the first displacement of the target, and a first individual corresponding to the first inductive coil Obtaining quantified sensing information about the external force in the Z-axis direction appearing in an area (S1020, S1060); And a second corresponding to a degree that the second resonance circuit deviates from the second state, the second displacement of the target, and the second inductive coil based on a difference between the reference resonance frequency and the second resonance frequency. It may further include the steps of obtaining (S1040, S1060) quantified detection information on the external force in the Z-axis direction appearing in the individual region.

The determination circuits 770 and 870 determine whether the touch force sensed for the first channel and the second channel is an input intended by the user, based on the results of steps S1020 and S1040, and an error or other not intended by the user. It is determined whether there is a signal fluctuation due to a factor (S1050).

When the touch force is determined to be the input intended by the user as a result of performing step S1050, the determination circuits 770 and 870 determine the location where the touch force is input and the magnitude of the touch force with respect to the region including the first channel and the second channel. Digitize and quantify (S1060).

11 is a diagram illustrating an inductive force sensor 1100 according to an embodiment of the present invention. 11 shows an inductive force sensor 1100 assuming a single button/channel/coil.

11 is an embodiment modified so that the first component 1140 of FIG. 11 performs the functions of the target layer 140 and the first component 130 in the embodiment of FIG. 1. That is, in FIG. 11, there is no separate target layer, and the displacement in the Z-axis direction according to the deformation of the first component 1140 is caused by inductive coupling between the inductive coil 1112 and the first component 1140. It can be detected through a change in inductance and a change in resonant frequency.

In FIG. 11, since the external force 1150, the substrate 1110, and the spacer layer 1160 are the same as the external force 150, the substrate 110, and the spacer layer 160 of FIG. 1, overlapping descriptions will be omitted.

Conventional inductive sensing techniques are difficult to accurately measure the displacement in the Z-axis direction of the first component 1140 due to the external force 1150, so as part of an effort to increase the accuracy of the measurement, the first When the target layer 140 is separately disposed under the part 130 and the target layer 140 is displaced in the Z-axis direction based on the deformation of the first part 130 in the Z-axis direction, the displacement is detected. However, in the embodiment of the present invention, since the change in inductance is detected through the difference in the resonant frequency of the differential signal, it is easy to quantify and digitize the measured value, so that the sensitivity of the displacement is high. Accordingly, as shown in FIG. 11, it is possible to detect and quantify the external force 1150 in the Z-axis direction with only one first component 1140. At this time, the first component 1140 and the inductive coil 1112 are connected to the inductive coil 1112 by inductive coupling between the first component 1140 and the inductive coil 1112 according to the distance in the Z-axis direction. The inductance of the resonant circuit to be changed varies. Accordingly, a change in inductance and a change in resonance frequency are detected only by displacement of the first component 1140 in the Z-axis direction, and the external force 1150 in the Z-axis direction can be detected and quantified. At this time, when the first component 1140 is deformed and the eddy current is induced in the portion closer to the inductive coil 1112, the change in the composite inductance due to the displacement in the Z-axis direction of the first component 1140 Is detected. Therefore, the first component 1140 may be implemented to exhibit electrical conductivity.

12 is a diagram illustrating an inductive force sensor 1200 according to an embodiment of the present invention.

FIG. 12 is an embodiment modified so that the second component 1230 of FIG. 12 performs the functions of the target layer 240 and the second component 230 in the embodiment of FIG. 2. That is, in FIG. 12, there is no separate target layer, and the displacement in the Z-axis direction according to the deformation of the individual regions 1232 in the second component 1230 is the plurality of inductive coils 1212 and the second component. It may be detected through a change in inductance and a change in resonant frequency caused by inductive coupling between the individual regions 1232 in the 1230.

In FIG. 12, since the substrate 1210 and the spacer layer 1260 are the same as the substrate 210 and the spacer layer 260 of FIG. 2, overlapping descriptions will be omitted.

Conventional inductive sensing techniques are difficult to accurately measure the displacement in the Z-axis direction of each of the individual regions 1232 in the second part 1230 due to an external force, so as part of an effort to increase the accuracy of the measurement, FIG. 2 As shown in, if the target layer 240 is separately disposed under the second part 230 and the target layer 240 is displaced in the Z-axis direction based on the deformation of the second part 230 in the Z-axis direction, Displacement is detected. However, in the embodiment of the present invention, since the change in inductance is detected through the difference in the resonant frequency of the differential signal, it is easy to quantify and digitize the measured value, so that the sensitivity of the displacement is high. Therefore, as shown in FIG. 12, the target layer is not disposed, and each of the individual regions 1232 is formed by inductive coupling between the individual regions 1232 in the second component 1230 and the plurality of inductive coils 1212. The displacement can be detected and quantified.

When an external force is applied to the first individual region of the individual regions 1232, the first individual region is deformed and the first individual region is displaced in the Z-axis direction, a first individual region among the plurality of inductive coils 1212 Whether or not an external force is applied to the first individual region and a magnitude of the external force may be determined based on a change in inductance sensed by the first inductive coil opposite to. Due to the inductive coupling between the first inductive coil and the first individual region, the displacement in the Z-axis direction of the first individual region (the deformation of the first individual region with respect to the first inductive coil and the displacement in the Z-axis direction) is first It affects the inductance of the first resonant circuit to which the inductive coil is connected. Based on the changed inductance of the first resonant circuit, the change in the first resonant frequency ω1 of the first resonant circuit is determined by the difference between the reference resonant frequency ω_ref and the first resonant frequency ω1 in the determination circuits 770 and 870. Based on the detection, a change in the first resonance frequency ω1 is quantified based on the difference between the reference resonance frequency ω_ref and the first resonance frequency ω1. The quantified change in the first resonance frequency ω1 may be digitized and stored in a separate memory or storage.

In this case, the inductance of the resonant circuit connected to each of the inductive coils 1212 is varied by inductive coupling between the individual regions 1232 in the second component 1230 and the opposite inductive coils 1212. Accordingly, a change in inductance and a change in resonance frequency are detected only by displacement of the individual regions 1232 in the Z-axis direction, and external force in the Z-axis direction can be detected and quantified. At this time, if an eddy current is induced in a portion of the individual regions 1232 in the second part 1230 where the distance to the inductive coils 1212 is close due to an external force, it is synthesized by displacement in the Z-axis direction. A change in inductance is detected. When the individual regions 1232 are implemented so that the eddy current is easily induced, the change in the composite inductance is more pronounced, so that the sensitivity of the sensor can be improved. In this case, in order to easily induce the eddy current in the individual regions 1232, the individual regions 1232 in the second component 1230 will be implemented to have higher electrical conductivity than the remaining regions in the second component 1230. I can. For example, it is possible to increase the electrical conductivity of the individual regions 1232 by arranging a metal thin film such as aluminum, which is a nonmagnetic and electric conductor, in the individual regions 1232, and the displacement of the individual regions 1232 in the Z-axis direction It can improve the sensitivity.

A method of operating a circuit according to an embodiment of the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the present invention, or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -A hardware device specially configured to store and execute program instructions such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of the program instructions include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The above-described hardware device may be configured to operate as one or more software modules to perform the operation of the present invention, and vice versa.

However, the present invention is not limited or limited by the embodiments. The same reference numerals in each drawing indicate the same members. The length, height, size, width, etc. introduced in the embodiments and drawings of the present invention may be exaggerated to aid understanding.

As described above, in the present invention, specific matters such as specific components, etc., and limited embodiments and drawings have been described, but this is provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. , If a person of ordinary skill in the field to which the present invention belongs, various modifications and variations are possible from these descriptions.

Therefore, the spirit of the present invention is limited to the described embodiments and should not be defined, and all things that are equivalent or equivalent to the claims as well as the claims to be described later belong to the scope of the invention. .

100, 200, 300, 400, 500, 600, 700, 800, 1100, 1200: inductive force sensor
110, 210, 1110, 1210: PCB
310a, 410a: one module consisting of a set of multiple coils
112, 212, 312, 412, 1112, 1212: inductive coil
512, 612: channel coil
514, 614: channel area
130, 230: deformable parts
232, 1232: individual areas
140, 240: target layer
150, 750: external force (external force)
452: range in which external force is input
160, 260, 1160, 1260: spacer layer
770, 870: decision circuit

Claims (19)

A first component exposed to an external force in the Z-axis direction and elastically deformable along the Z-axis direction by the external force in the Z-axis direction;
An inductive coil formed on a substrate spaced apart from the first component;
A first resonant circuit coupled to the inductive coil and having a first resonant frequency resulting from a first inductance formed in the inductive coil based on the displacement of the first component with respect to the inductive coil;
A first oscillator for applying a first AC signal to the first resonance circuit;
A reference resonant circuit having the same impedance as a predetermined first state among states that the first resonant circuit may have;
A reference oscillator having the same characteristics as the first oscillator and applying a reference AC signal to the reference resonance circuit; And
Receiving a first electrical signal formed in the first resonant circuit, receiving a reference electrical signal formed in the reference resonant circuit, the first resonant frequency of the first electrical signal and the reference resonant frequency of the reference electrical signal A determination circuit for determining the displacement of the first component and the external force in the Z-axis direction based on the determination circuit;
Inductive force sensor comprising a. The method of claim 1,
The determination circuit is
Detecting a difference between the reference resonance frequency and the first resonance frequency of the reference electrical signal formed in the reference resonance circuit under the influence of the reference AC signal applied to the reference resonance circuit,
Based on the difference between the reference resonant frequency and the first resonant frequency, the degree to which the first resonant circuit deviates from the first state, the relative displacement of the first component with respect to the inductive coil, and the Z-axis direction An inductive force sensor that acquires quantified sensing information for the external force of. The method of claim 1,
The determination circuit is
If the difference between the reference resonant frequency and the first resonant frequency is greater than or equal to a first threshold value, the first resonant frequency is considered to have caused a significant change, and the inductive force sensor determines that the external force in the Z-axis direction is input. The method of claim 1,
The inductive coil is an inductive force sensor formed by overlapping a plurality of unit coil windings in a concentric structure. The method of claim 1,
The inductive coil is formed of a set of a plurality of unit coil windings, and the plurality of unit coil windings are arranged so as to be spaced apart from each other as they move away from a specific position. The method of claim 5,
The determination circuit is
Quantified sensing information about the external force in the Z-axis direction in the area covered by the inductive coil based on a change pattern of the difference between the reference resonance frequency and the first resonance frequency appearing in the time domain, and the Z-axis direction Inductive force sensor for recognizing an intended user gesture by the external force of. The method of claim 1,
The determination circuit is
An operator for obtaining a difference between the first resonance frequency and the reference resonance frequency;
A low pass filter connected to the output terminal of the operator to remove a high frequency component; And
A time-to-digital converter connected to the output terminal of the low-pass filter to digitally count a frequency of a differential frequency component signal corresponding to a difference between the first resonance frequency and the reference resonance frequency;
Inductive force sensor comprising a. The method of claim 1,
The determination circuit is
An inductive force sensor that performs a calibration process based on a difference between the first resonance frequency and the reference resonance frequency while the first resonance circuit is forcibly adjusted externally to be in the first state. A second component including a plurality of individual regions that are exposed to an external force in the Z-axis direction and elastically deformable along the Z-axis direction by the external force in the Z-axis direction;
A plurality of inductive coils formed on a substrate spaced apart from the second component, corresponding to each of the plurality of individual regions, and disposed to face each of the plurality of individual regions;
The first inductive coil is coupled to a first inductive coil among the plurality of inductive coils and is caused by a first inductance formed in the first inductive coil based on a first displacement of the individual regions with respect to the first inductive coil. A first channel resonance circuit having one resonance frequency;
A first oscillator for applying a first AC signal to the first channel resonance circuit;
The second inductance is coupled to a second inductive coil among the plurality of inductive coils and is caused by a second inductance formed in the second inductive coil based on a second displacement of the individual regions with respect to the second inductive coil. A second channel resonance circuit having 2 resonance frequencies;
A second oscillator for applying a second AC signal to the second channel resonance circuit;
A reference resonance circuit having the same impedance as a predetermined first state among states that the first channel resonance circuit can have and a second predetermined state among states that the second channel resonance circuit can have;
A reference oscillator that has the same characteristics as the first oscillator and the second oscillator and applies a reference AC signal to the reference resonant circuit; And
A first electrical signal formed in the first channel resonance circuit, a second electrical signal formed in the second channel resonance circuit, and a reference electrical signal formed in the reference resonance circuit are received, and the first electrical signal The first displacement, the second displacement, and the external force in the Z-axis direction are input based on the first resonant frequency, the second resonant frequency of the second electrical signal, and the reference resonant frequency of the reference electrical signal. A determination circuit for determining a position and the external force;
Inductive force sensor comprising a. The method of claim 9,
The determination circuit is
Detecting a difference between the reference resonance frequency and the first resonance frequency of the reference electrical signal formed in the reference resonance circuit under the influence of the reference AC signal applied to the reference resonance circuit,
Based on the difference between the reference resonant frequency and the first resonant frequency, a degree of the first channel resonant circuit deviating from the first state, the first displacement of the individual regions, and a first corresponding to the first inductive coil 1 Acquire quantified detection information about the external force in the Z-axis direction appearing in an individual area,
Detecting a difference between the reference resonance frequency and the second resonance frequency,
Based on the difference between the reference resonance frequency and the second resonance frequency, the second channel resonance circuit deviates from the second state, the second displacement of the individual regions, and a second corresponding to the second inductive coil. 2 An inductive force sensor that acquires quantified sensing information about the external force in the Z-axis direction appearing in individual regions. The method of claim 9,
The determination circuit is
If at least one of the difference between the reference resonance frequency and the first resonance frequency, or the difference between the reference resonance frequency and the second resonance frequency is greater than or equal to a first threshold value, at least one of the first resonance frequency or the second resonance frequency An inductive force sensor configured to determine that the external force in the Z-axis direction is input by considering at least one significant change. The method of claim 9,
The determination circuit is
Based on a first change pattern of the difference between the reference resonance frequency and the first resonance frequency in a time domain and a second change pattern of the difference between the reference resonance frequency and the second resonance frequency in the time domain, the first Quantified sensing information for the external force in the Z-axis direction in a first region covered by the inductive coil, and quantified sensing information for the external force in the Z-axis direction in a second region covered by the second inductive coil And an inductive force sensor for recognizing a user gesture intended by the external force in the Z-axis direction. The method of claim 9,
The determination circuit is
Based on the difference between the reference resonance frequency and the first resonance frequency, and the difference between the reference resonance frequency and the second resonance frequency, the external force in the Z-axis direction in a first region covered by the first inductive coil The quantified detection information for, and the quantified detection information for the external force in the Z-axis direction are extracted from the second area covered by the second inductive coil, and the external force in the Z-axis direction is intended by the user. Inductive force sensor to determine whether or not it is a faulty input. The method of claim 9,
The determination circuit is
An operator for multiplying the first resonant frequency and the reference resonant frequency, and multiplying the second resonant frequency and the reference resonant frequency;
A low pass filter connected to the output terminal of the operator to remove a high frequency component; And
The frequency of the first differential frequency component signal, which is connected to the output terminal of the low-pass filter and corresponds to the difference between the first resonance frequency and the reference resonance frequency, is digitally counted, and the difference between the second resonance frequency and the reference resonance frequency is calculated. A time-to-digital converter for digitally counting the frequency of the corresponding second differential frequency component signal;
Inductive force sensor comprising a. A first component exposed to an external force in the Z-axis direction and elastically deformable along the Z-axis direction by the external force in the Z-axis direction, and an inductive coil formed on a substrate spaced apart from the first component; In the method of operating the inductive force sensor comprising a,
A first resonant circuit having a first oscillator coupled to the inductive coil and having a first resonant frequency resulting from a first inductance formed in the inductive coil based on a displacement of the first component with respect to the inductive coil Applying a first AC signal to the device;
Applying, by a reference oscillator having the same characteristics as the first oscillator, a reference AC signal to a reference resonant circuit having the same impedance as a predetermined first state among states that the first resonant circuit may have;
Receiving, by a determination circuit, a first electric signal formed in the first resonant circuit under the influence of the first AC signal;
Receiving, by the determination circuit, a reference electric signal formed in the reference resonance circuit; And
Determining, by the determination circuit, a displacement of the first component and the external force in the Z-axis direction based on the first resonant frequency of the first electrical signal and the reference resonant frequency of the reference electrical signal;
Operating method of the inductive force sensor comprising a. The method of claim 15,
The step of determining the external force in the Z-axis direction by the determination circuit
Detecting a difference between the reference resonance frequency and the first resonance frequency; And
Based on the difference between the reference resonant frequency and the first resonant frequency, the degree to which the first resonant circuit deviates from the first state, the relative displacement of the first component with respect to the inductive coil, and the Z-axis direction Obtaining quantified sensing information about the external force of
Operating method of the inductive force sensor comprising a. The method of claim 15,
Quantified sensing information about the external force in the Z-axis direction in a region covered by the inductive coil based on a change pattern of the difference between the reference resonance frequency and the first resonance frequency appearing in the time domain by the determination circuit, and Recognizing a user gesture intended by the external force in the Z-axis direction;
The method of operating the inductive force sensor further comprising. In the operating method of the inductive force sensor,
The inductive force sensor
A second component including a plurality of individual regions that are exposed to an external force in the Z-axis direction and elastically deformable along the Z-axis direction by the external force in the Z-axis direction; And
A plurality of inductive coils formed on a substrate spaced apart from the second component, corresponding to each of the plurality of individual regions, and disposed to face each of the plurality of individual regions;
Including,
A first oscillator is coupled to a first inductive coil among the plurality of inductive coils and is formed in the first inductive coil based on a first displacement of the individual regions with respect to the first inductive coil. Applying a first AC signal to a first channel resonant circuit having a first resonant frequency due to inductance;
A second oscillator is coupled to a second inductive coil among the plurality of inductive coils, and is formed in the second inductive coil based on a second displacement of the individual regions with respect to the second inductive coil. Applying a second AC signal to a second channel resonant circuit having a second resonant frequency due to inductance;
A reference oscillator having the same characteristics as the first oscillator and the second oscillator may have a predetermined first state among states that the first channel resonance circuit may have and a state that the second channel resonance circuit may have. Applying a reference AC signal to a reference resonant circuit having the same impedance as the second state;
Receiving, by a determination circuit, a first electric signal formed in the first channel resonance circuit under the influence of the first AC signal;
Receiving, by a determination circuit, a second electric signal formed in the second channel resonance circuit under the influence of the second AC signal;
Receiving, by the determination circuit, a reference electric signal formed in the reference resonance circuit; And
The determination circuit comprises the first displacement, the second displacement, based on the first resonance frequency of the first electrical signal, the second resonance frequency of the second electrical signal, and the reference resonance frequency of the reference electrical signal, And determining a position to which the external force in the Z-axis direction is input and the external force.
Operating method of the inductive force sensor comprising a. The step of determining, by the determination circuit, a position to which the external force in the Z-axis direction is input and the external force
Detecting a difference between the reference resonance frequency and the first resonance frequency;
Detecting a difference between the reference resonance frequency and the second resonance frequency;
Based on the difference between the reference resonant frequency and the first resonant frequency, the first resonant circuit deviates from the first state, the first displacement of the individual regions, and a first corresponding to the first inductive coil Acquiring quantified sensing information on the external force in the Z-axis direction appearing in an individual area; And
Based on the difference between the reference resonant frequency and the second resonant frequency, the second resonant circuit deviates from the second state, the second displacement of the individual regions, and a second corresponding to the second inductive coil Acquiring quantified sensing information on the external force in the Z-axis direction appearing in an individual area;
Operating method of the inductive force sensor comprising a.

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