Electronic device and method for operating resonator element at resonant frequency

Abstract

The present invention provides an electronic device for operating a resonator element at a resonant frequency, the electronic device comprising: a control unit, a control unit configured to control driving of the resonator element connected to an output terminal of the amplifier unit in a manner in which a driving signal is acquired according to a first clock signal and input to the amplifier unit; a phase difference detection unit configured to detect a phase difference between a voltage and a current at the output terminal of the amplifier unit; and a frequency changing unit configured to change a frequency of the first clock signal based on the phase difference detected by the phase difference detecting unit to converge an operating frequency of the resonator element to the resonant frequency.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Korean Patent Application No. 10-2023-0093299, filed on Jul. 18, 2023, which is hereby incorporated by reference in its entirety for all purposes. Technical Field

[0003] The present invention relates to electronic devices and methods for operating a resonator element at a resonant frequency, and more particularly, to electronic devices and methods for operating a resonator element (such as a linear resonant actuator (LRA)) at a resonant frequency. Background Art

[0004] Linear resonant actuators (LRA, generally interpreted as a concept including a motor) are used to provide tactile feedback to users in mobile devices, game consoles, home appliances, medical devices, etc. Figure 1 As shown, it is composed of a vibrating body, a spring, a coil, and other chassis and a casing.

[0005] The linear resonant actuator is driven by the interaction between the coil and the vibrating body, and its operating principle is as follows. When current flows through the coil, a magnetic field is generated around the coil, the force generated by the magnetic field acts on the vibrating body, and the vibrating body fixed by the spring vibrates at a specific position. In this case, the vibration frequency of the vibrating body is determined by the characteristics and mass of the spring.

[0006] In the operation of such a linear resonant actuator, it is advantageous to operate at a resonant frequency, where the vibration is maximized by the resonance phenomenon, so as to maximize the momentum of the actuator and minimize the energy loss of the vibration. That is, when operating at a resonant frequency, the linear resonant actuator has a higher operating efficiency and is able to maximize the output of the input. The linear resonant actuator can be electrically modeled as an RLC parallel circuit, and the impedance of the RLC parallel circuit is maximum at a resonant frequency where the phase of the input voltage is the same as the phase of the current. When the impedance is maximum, the current is small compared to the input voltage, which means that the vibration is relatively large.

[0007] For high operating efficiency of the linear resonant actuator, an attempt is made to generate an actuator input signal (i.e., a driving voltage or a driving current) that matches the resonant frequency, and then input the actuator input signal. However, since the resonant frequency has the characteristic of varying with the magnitude of the actuator input signal, there is a limitation that the resonant frequency that varies with the magnitude of the input signal cannot be accurately matched. Specifically, the mass of the vibrating body constituting the linear resonant actuator determines the inertia of the vibrating body, which affects the vibration frequency. When the magnitude of the input signal changes, the magnitude of the force acting on the vibrating body changes, so the movement and inertia of the vibrating body may change, thereby affecting the resonant frequency. As described above, since the resonant frequency varies with the magnitude of the input signal, it is difficult to accurately predict the resonant frequency and input the resonant frequency to the actuator.

[0008] The background technology of the present invention is disclosed in Korean Patent Application Publication No. 10-2021-0138373 (published on November 19, 2021). Summary of the invention

[0009] The present invention is directed to solving the above-mentioned problems and, according to one aspect, aims to provide a method of operating a resonator element, such as a linear resonant actuator, at a resonant frequency.

[0010] The present invention provides an electronic device for operating a resonator element at a resonant frequency, which may include: a control unit, which is configured to control the driving of the resonator element connected to the output terminal of the amplifier unit in a manner in which a driving signal is obtained according to a first clock signal and the driving signal is input to an amplifier unit; a phase difference detection unit, which is configured to detect the phase difference between the voltage and the current at the output terminal of the amplifier unit; and a frequency changing unit, which is configured to change the frequency of the first clock signal based on the phase difference detected by the phase difference detection unit to converge the operating frequency of the resonator element to the resonant frequency.

[0011] In the present invention, the first clock signal can define the operating frequency of the resonator element because the control unit operates to control the drive of the resonator element connected to the output terminal of the amplifier unit in a manner in which the control unit obtains a drive signal based on the first clock signal and inputs the drive signal to the amplifier unit.

[0012] In the present invention, the frequency changing unit is operable to cancel the phase difference by changing the frequency of the first clock signal based on the phase difference to adjust the operating frequency of the resonator element.

[0013] In the present invention, when the phase difference is defined as the phase difference of the voltage relative to the current, the frequency changing unit may increase the frequency of the first clock signal to increase the operating frequency of the resonator element when the phase difference has a negative value, and reduce the frequency of the first clock signal to reduce the operating frequency of the resonator element when the phase difference has a positive value.

[0014] In the present invention, the frequency changing unit may include a multiplexer, an accumulator, a counter and a trigger, and when the accumulator and the counter operate according to a second clock signal, a state transition of the first clock signal may occur, the multiplexer outputs a first value or a second value according to the value of the phase difference, the accumulator accumulates the output value of the multiplexer to a default value (default value) preset as an initial value and outputs the accumulated value, the counter outputs a count value according to the second clock signal, and the trigger operates to switch when the output value of the accumulator is equal to the output value of the counter.

[0015] In the present invention, when the phase difference has a negative value, the first value having a negative value can be output from the multiplexer, so that the output value of the accumulator can be reduced, and the switching frequency of the trigger can be increased accordingly, so that the frequency of the first clock signal can be increased.

[0016] In the present invention, when the phase difference has a positive value, the second value with a positive value can be output from the multiplexer, so that the output value of the accumulator can be increased, and the switching frequency of the trigger can be reduced accordingly, so that the frequency of the first clock signal can be reduced.

[0017] In the present invention, the counter may be configured such that the count value is reset when the output value of the accumulator and the output value of the counter are equal.

[0018] The present invention provides a method for operating a resonator element at a resonant frequency, which may include: controlling the drive of the resonator element connected to the output terminal of the amplifier unit in a manner in which a drive signal is obtained according to a first clock signal and the drive signal is input to an amplifier unit; detecting the phase difference between the voltage and current at the output terminal of the amplifier unit; and changing the frequency of the first clock signal based on the detected phase difference to converge the operating frequency of the resonator element to the resonant frequency.

[0019] According to the present invention, the drive of the resonator element connected to the output terminal of the amplifier unit is controlled in a manner in which a drive signal is obtained based on the first clock signal and the drive signal is input to the amplifier unit, wherein the resonator element, such as a linear resonant actuator, can operate precisely at the resonant frequency by: detecting the phase difference between the voltage and the current at the output terminal of the amplifier unit; and adopting a feedback topology that changes the frequency of the first clock signal based on the detected phase difference to converge the operating frequency of the resonator element to the resonant frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a diagram showing an example of the structure of a general linear resonant actuator.

[0021] Figure 2 and Figure 3 is a block diagram showing an electronic device for operating a resonator element at a resonance frequency according to the present embodiment.

[0022] Figure 4 and Figure 5 is an exemplary diagram for describing a resonant frequency in an electronic device for operating a resonator element at a resonant frequency according to the present embodiment.

[0023] Figure 6 is a flow chart illustrating a method of operating a resonator element at a resonant frequency according to the present embodiment. DETAILED DESCRIPTION

[0024] Hereinafter, with reference to the accompanying drawings, embodiments of electronic devices and methods for operating resonator elements at a resonant frequency according to the present invention will be described. Here, for the sake of clarity and convenience of description, the thickness of the lines shown in the drawings, the size of the constituent elements, etc. may be exaggerated. In addition, the terms used below are defined in consideration of the functions in the present invention and may vary according to the intention or common practice of the user or operator. Therefore, the definition of terms should be based on the entire content of this specification.

[0025] Figure 2 and Figure 3 is a block diagram showing an electronic device for operating a resonator element at a resonance frequency according to the present embodiment, and Figure 4 and Figure 5 is an exemplary diagram for describing a resonant frequency in an electronic device for operating a resonator element at a resonant frequency according to the present embodiment.

[0026] First, refer to Figure 2The electronic device for operating a resonator element at a resonant frequency according to the present embodiment (hereinafter, the electronic device) includes a storage unit 10, a control unit 20, an amplifier unit 30, a first filter unit 41 and a second filter unit 42, a phase difference detection unit 50, and a frequency change unit 60, and is configured to control and operate the resonator element LRA. The resonant element LRA of the present embodiment may correspond to a linear resonant actuator (LRA) for providing tactile feedback to a user in a mobile device, a game console, a home appliance, a medical device, etc., and therefore, each configuration 10 to 50 of the electronic device of the present embodiment may be integrally implemented as a processor (e.g., an application processor) installed on the mobile device, the game console, the home appliance, or the medical device to control and operate the above-mentioned resonant element LRA.

[0027] The storage unit 10 may store driving data (e.g., voltage magnitude data and current magnitude data) required to drive the resonator element LRA, and the control unit 20 described below with reference to the driving data controls the driving of the resonant element LRA in a manner in which a driving signal is acquired (generated) and then input to the amplifier unit 30. The storage unit 10 for storing the driving data referred to in the acquisition of the driving signal may be implemented as a volatile storage medium and / or a nonvolatile storage medium, such as a read-only memory (ROM) and / or a random access memory (RAM), for example.

[0028] The control unit 20 may correspond to a memory controller that performs operations of reading and writing data for the memory cell 10 according to the first clock signal CLK1 output from the flip-flop 68 of the frequency change unit 60 described below. In the present embodiment, the control unit 20 controls the driving of the resonator element LRA connected to the output terminal of the amplifier unit 30 in a manner in which a driving signal (e.g., a voltage signal or a current signal) is acquired (generated) according to the first clock signal CLK1 and inputted to the amplifier unit 30. That is, the control unit 20 operates to read the driving data from the memory cell 10 in synchronization with the first clock signal CLK1 to acquire the driving signal and input the driving signal to the amplifier unit 30, and therefore, the first clock signal CLK1 is used as a factor defining the operating frequency of the resonator element LRA. The first clock signal CLK1 may correspond to a local clock signal for the read and write operations of the control unit 20 of the memory cell 10.

[0029] The amplifier unit 30 corresponds to a driver that substantially drives the resonator element LRA in a manner in which the driving signal input from the control unit 20 is amplified and input to the resonator element LRA, and may be implemented as a conventional amplifier. The voltage V and the current I at the output terminal of the amplifier unit 30 (i.e., the voltage and the current input to the resonator element LRA) may be sensed by an ADC interface of an electronic device, and the sensed voltage and current are denoised by the first filter unit 41 and the second filter unit 42 (e.g., LPF), respectively, and are input to the phase difference detection unit 50.

[0030] The phase difference detection unit 50 detects the phase difference between the sensed voltage and the sensed current at the output terminal of the amplifier unit 30, and detects the difference between the corresponding zero crossing points of the sensed voltage and the sensed current as the phase difference. In the present embodiment, the phase difference can be defined as "the phase difference of the voltage relative to the current", so that the phase difference with a negative value means that the phase of the voltage leads the phase of the current, and the phase difference with a positive value means that the phase of the voltage lags behind the phase of the current. Figure 4 A state is shown in which the phase of the voltage lags behind the phase of the current when the phase difference has a positive value.

[0031] At the same time, if Figure 5 As shown, the resonance frequency varies according to the magnitude of the input signal of the resonator element LRA (which may correspond to the driving signal output from the control unit 20). Near the resonance frequency at which the phase difference has a value of "0", when the phase difference has a negative value, it is necessary to increase the operating frequency of the resonator element LRA to converge the phase difference to the value of "0" ( Figure 5 direction ①), and when the phase difference has a positive value, it is necessary to reduce the operating frequency of the resonator element LRA to converge the phase difference to the value "0" ( Figure 5 As described above, in the present embodiment, the factor defining the operating frequency of the resonator element LRA corresponds to the first clock signal CLK1, and for this purpose, the frequency changing unit 60 is configured to change the frequency of the first clock signal CLK1.

[0032] Specifically, the frequency changing unit 60 changes the frequency of the first clock signal CLK1 based on the phase difference detected by the phase difference detecting unit 50 so as to converge the operating frequency of the resonator element LRA to the resonant frequency, and more specifically, the frequency changing unit 60 operates to eliminate the phase difference by changing the frequency of the first clock signal CLK1 based on the detected phase difference to adjust the operating frequency of the resonator element LRA.

[0033] In this case, when the phase difference has a negative value, the frequency changing unit 60 increases the frequency of the first clock signal CLK1 to increase the operating frequency of the resonator element LRA ( Figure 5direction ① in the middle), and when the phase difference has a positive value, the frequency changing unit 60 reduces the frequency of the first clock signal CLK1 to reduce the operating frequency of the resonator element LRA ( Figure 5 Direction ②).

[0034] In order to achieve the above functions, Figure 3 As shown, the frequency changing unit 60 may be configured to include first to third comparators 61 to 63, a multiplexer 64, an adder 65, an accumulator 66, a counter 67, and a flip flop 68. The accumulator 66, the counter 67, and the flip flop 68 may operate in synchronization with the second clock signal CLK2, and the second clock signal CLK2 may correspond to the system clock signal.

[0035] The phase difference detected by the phase difference detection unit 50 is input to the first comparator 61 and the second comparator 62, and the first comparator 61 determines whether the phase difference corresponds to the value "0", and the second comparator 62 determines whether the phase difference is less than the value "0", and then outputs the determination result to the multiplexer 64. Therefore, the multiplexer 64 is configured to output any one of the first value, the second value, and the third value according to the value of the phase difference. Figure 3 In the example, when the output from the first comparator 61 and the second comparator 62 is "00" (i.e., the phase difference is greater than the value "0"), the multiplexer 64 outputs the value "+1" as the first value (which is a positive value), when the output from the first comparator 61 and the second comparator 62 is "01" (i.e., the phase difference is less than the value "0"), the multiplexer 64 outputs the value "-1" as the second value (which is a negative value), and when the output from the first comparator 61 and the second comparator 62 is "10" or "11" (i.e., the phase difference is the value "0"), the multiplexer 64 outputs the value "0" as the third value.

[0036] The accumulator 66 accumulates the output value of the multiplexer 64 to a preset default value and outputs the accumulated value. The default value is a tuning parameter, which can be designed and defined as a specific value according to the designer's intention, and can be defined as a different value for the corresponding situation in which the phase difference has a positive value or a negative value, so as to adjust the frequency of the first clock signal CLK1. When the phase difference has a negative value, the first value with a negative value is output from the multiplexer 64, and the output value of the accumulator 66 is reduced (reduced by 1 in the above example, when the default value is x, the output value of the accumulator 66 is reduced to x, x-1, x-2 in synchronization with the second clock signal CLK2...), when the phase difference has a positive value, the second value with a positive value is output from the multiplexer 64, and the output value of the accumulator 66 is increased (increased by 1 in the above example, when the default value is y, the output value of the accumulator 66 is increased to y, y+1, y+2 in synchronization with the second clock signal CLK2...).

[0037] The counter 67 outputs a count value (i.e., a count value of a rising edge of the second clock signal CLK2) according to the second clock signal CLK2, and compares the output value of the accumulator 66 and the output value of the counter 67 in the third comparator 63. When the output value of the accumulator 66 and the output value of the counter 67 are different, a value "0" is output from the third comparator 63, and when the output value of the accumulator 66 and the output value of the counter 67 are the same, a value "1" is output from the third comparator 63 and the counter 67 is reset. The output of the third comparator 63 is input to the flip-flop 68.

[0038] The flip-flop 68 is a switching flip-flop that receives the output value from the third comparator 63 and outputs the first clock signal CLK1 to the control unit 20. When a value "1" is output from the third comparator 63, the flip-flop 68 operates to switch, and the switching operation of the flip-flop 68 causes a state transition of the first clock signal CLK1 (i.e., high level to low level or low level to high level).

[0039] The process of adjusting the frequency of the first clock signal CLK1 based on the circuit structure of the frequency changing unit 60 described above is as follows. First, when the phase difference detected by the phase difference detection unit 50 has a negative value, a first value (e.g., -1) having a negative value is output from the multiplexer 64, and the output value of the accumulator 66 decreases. As the output value of the accumulator 66 decreases, the time required for the output value of the accumulator 66 to be equal to the output value of the counter 67 decreases, which means that the switching frequency of the flip-flop 68 increases within a specific time period (e.g., a 10 time period of the second clock signal CLK2). Therefore, the frequency of the first clock signal CLK1 also increases as the switching frequency of the flip-flop 68 increases. As the frequency of the first clock signal CLK1 increases, the operating frequency of the resonator element LRA increases, and the phase difference is eliminated, so that the operating frequency of the resonator element LRA converges to the resonant frequency.

[0040] When the phase difference detected by the phase difference detection unit 50 has a positive value, a second value (e.g., +1) having a positive value is output from the multiplexer 64, and the output value of the accumulator 66 increases. As the output value of the accumulator 66 increases, the time required for the output value of the accumulator 66 to be equal to the output value of the counter 67 increases, which means that the switching frequency of the flip-flop 68 decreases within a certain time period (e.g., a 10 time period of the second clock signal CLK2). Therefore, the frequency of the first clock signal CLK1 also decreases as the switching frequency of the flip-flop 68 decreases. As the frequency of the first clock signal CLK1 decreases, the operating frequency of the resonator element LRA decreases, and the phase difference is eliminated, so that the operating frequency of the resonator element LRA converges to the resonant frequency.

[0041] like Figure 6As shown, the configuration of the present embodiment described above may also be implemented as a method for operating a resonator element at a resonant frequency, which method may include: step S100, controlling the driving of the resonator element LRA connected to the output terminal of the amplifier unit 30 in a manner in which a driving signal is acquired according to the first clock signal CLK1 and the driving signal is input to the amplifier unit 30; step S200, detecting a phase difference between a voltage and a current at the output terminal of the amplifier unit 30; and step S300, changing the frequency of the first clock signal CLK1 based on the phase difference detected in step S200 so as to converge the operating frequency of the resonator element LRA to the resonant frequency.

[0042] As described above, according to the present invention, the driving of a resonator element connected to an output terminal of an amplifier unit is controlled in a manner in which a driving signal is acquired according to a first clock signal and input to the amplifier unit, wherein the resonator element such as a linear resonant actuator (LRA) can be accurately operated at a resonant frequency by: detecting a phase difference between a voltage and a current at the output terminal of the amplifier unit; and adopting a feedback topology in which the frequency of the first clock signal is changed based on the detected phase difference to converge the operating frequency of the resonator element to the resonant frequency.

[0043] As used in this specification, the term "unit" may include a unit implemented in hardware, software or firmware, and may be used interchangeably with terms such as logic, logic block, component or circuit, for example. The unit may be a component configured as a whole, or the smallest unit or a part of a component that performs one or more functions. For example, according to one embodiment, the unit may be implemented in the form of an application-specific integrated circuit (ASIC). In addition, the configuration described in this specification may be implemented as a method or process, a device, a software program, a data stream or a signal. Even if only a single form of implementation is described (for example, only a method is described), the described features may also be implemented in other forms (for example, a device or program). The device may be implemented as appropriate hardware, software, firmware, etc. For example, the method may be implemented by a device such as a processor, which generally refers to a processing device including a computer, a microprocessor, an integrated circuit, a programmable logic device, etc. The processor also includes a communication device such as a computer, a cellular phone, a portable / personal information terminal (personal digital assistant (PDA)) and other devices that are conducive to information communication with an end user.

[0044] Although the present invention has been described with reference to the embodiment shown in the accompanying drawings, this embodiment is described for illustration only, and those skilled in the art will understand that various modifications of this embodiment and any other embodiments equivalent thereto are available. Therefore, the true technical protection scope of the present invention should be determined by the appended claims.

Claims

1. An electronic device for operating a resonator element at a resonant frequency, characterized in that The electronic device comprises: a control unit configured to control driving of the resonator element connected to an output terminal of the amplifier unit by acquiring a driving signal according to a first clock signal and inputting the driving signal to the amplifier unit; a phase difference detection unit for detecting a phase difference between a voltage and a current at the output terminal of the amplifier unit; and A frequency changing unit is configured to change the frequency of the first clock signal based on the phase difference detected by the phase difference detecting unit so as to converge the operating frequency of the resonator element to the resonance frequency.

2. The electronic device according to claim 1, characterized in that: The first clock signal may define the operating frequency of the resonator element, since the control unit controls the driving of the resonator element connected to the output terminal of the amplifier unit by acquiring the driving signal according to the first clock signal and inputting the driving signal to the amplifier unit.

3. The electronic device according to claim 1, characterized in that: The frequency changing unit is configured to cancel the phase difference by changing the frequency of the first clock signal based on the phase difference, so as to adjust the operating frequency of the resonator element.

4. The electronic device according to claim 3, characterized in that: When the phase difference is defined as a phase difference between the voltage and the current, the frequency changing unit increases the frequency of the first clock signal to increase the operating frequency of the resonator element when the phase difference has a negative value, and decreases the frequency of the first clock signal to decrease the operating frequency of the resonator element when the phase difference has a positive value.

5. The electronic device according to claim 4, characterized in that: The frequency changing unit includes a multiplexer, an accumulator, a counter and a flip-flop, and Wherein, the accumulator and the counter operate in response to a second clock signal, the multiplexer outputs a first value or a second value according to the value of the phase difference, the accumulator accumulates the output value of the multiplexer to a default value preset as an initial value and outputs the accumulated value, the counter outputs a count value according to the second clock signal, and the trigger is used to switch when the output value of the accumulator is equal to the output value of the counter to generate a state transition of the first clock signal.

6. The electronic device according to claim 5, characterized in that: When the phase difference has a negative value, the first value having a negative value is output from the multiplexer, so that the output value of the accumulator decreases, and the switching frequency of the flip-flop increases accordingly, so that the frequency of the first clock signal increases.

7. The electronic device according to claim 5, characterized in that: When the phase difference has a positive value, the second value having a positive value is output from the multiplexer, so that the output value of the accumulator increases, and the switching frequency of the flip-flop decreases accordingly, so that the frequency of the first clock signal decreases.

8. The electronic device according to claim 5, characterized in that: The counter is configured to reset the count value when the output value of the accumulator and the output value of the counter are equal.

9. A method of operating a resonator element at a resonant frequency, characterized in that The method comprises: controlling the driving of the resonator element connected to the output terminal of the amplifier unit by acquiring a driving signal according to a first clock signal and inputting the driving signal to the amplifier unit; detecting a phase difference between a voltage and a current at the output terminal of the amplifier unit; and The frequency of the first clock signal is changed based on the detected phase difference to converge the operating frequency of the resonator element to the resonant frequency.

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