Tactile actuator and control method therefor

1. A tactile actuator, comprising:

a housing having an accommodation space therein;

a cap configured to cover at least a portion of the accommodation space;

a vibrator disposed in the accommodation space;

an elastic member configured to connect the housing and the vibrator such that the vibrator vibrates with respect to the housing;

a coil configured to form a magnetic field to drive the vibrator; and

a controller configured to determine one of a plurality of preset driving modes based on collected driving information, and determine a characteristic of a current to be applied to the coil based on the determined driving mode,

wherein the controller is configured to:

determine a frequency of the current to be a first set frequency when the driving mode is a first set mode, and

determine the frequency of the current to be a second set frequency when the driving mode is a set mode other than the first set mode, the second set frequency being lower than the first set frequency,

determine a waveform of the current to be a square wave or a pulse wave when the driving mode is a second set mode, and

determine the waveform of the current to be a sine wave when the driving mode is the first set mode,

wherein the first set frequency is equal to or greater than a threshold frequency of the tactile actuator,

wherein the second set frequency is smaller than the threshold frequency of the tactile actuator, and

wherein the threshold frequency is a minimum frequency at which periodic vibration is formed without showing collapse of a waveform generated based on an input current.

2. The tactile actuator of claim 1 , wherein a mass of the vibrator is below 2 grams (g), an elasticity coefficient of the elastic member is below 2.021 newtons per millimeter (N/mm), and a resonant frequency of the tactile actuator is below 160 hertz (Hz).

3. The tactile actuator of claim 1 , wherein the first set frequency is a value below 160 Hz.

4. The tactile actuator of claim 1 , wherein the controller is configured to:

determine the waveform of the current to be a sine wave when the driving mode is a third set mode.

5. The tactile actuator of claim 1 , wherein the driving mode includes a general vibration mode, a tapping mode, and a rolling mode.

6. The tactile actuator of claim 5 , wherein the controller is configured to:

determine a frequency of the current to be a first set frequency when the driving mode is the general vibration mode,

determine the frequency of the current to be a second set frequency when the driving mode is the tapping mode, the second set frequency being lower than the first set frequency, and

determine the frequency of the current to be a third set frequency when the driving mode is the rolling mode, the third set frequency being higher than the second set frequency and lower than the first set frequency.

7. The tactile actuator of claim 1 , further comprising:

an information providing device configured to provide information collected by the controller,

wherein the information providing device comprises at least one of a user interface configured to receive an instruction of a user, a sensor configured to sense an external environment, a memory configured to store data, and a communicator configured to receive information through communication with another communication device.

8. A control method for a tactile actuator including a housing having an accommodation space therein, a cap configured to cover at least a portion of the accommodation space, a vibrator disposed in the accommodation space, an elastic member configured to connect the housing and the vibrator such that the vibrator vibrates with respect to the housing, and a coil configured to form a magnetic field to drive the vibrator, the control method comprising:

collecting driving information;

determining one of a plurality of preset driving modes based on the collected driving information;

determining a frequency of a current to be applied to the coil based on the determined driving mode; and

applying the current to the coil,

wherein in the determining a frequency of a current to be applied to the coil,

determining a frequency of the current to be a first set frequency when the driving mode is a first set mode, and

determining the frequency of the current to be a second set frequency when the driving mode is a set mode other than the first set mode, the second set frequency being lower than the first set frequency,

determining a waveform of the current to be a square wave or a pulse wave when the driving mode is a second set mode, and

determining the waveform of the current to be a sine wave when the driving mode is the first set mode,

wherein the first set frequency is equal to or greater than a threshold frequency of the tactile actuator,

wherein the second set frequency is smaller than the threshold frequency of the tactile actuator, and

wherein the threshold frequency is a minimum frequency at which periodic vibration is formed without showing collapse of a waveform generated based on an input current.

9. The control method of claim 8 , further comprising:

determining a waveform of the current to be applied to the coil based on the determined driving mode.

10. The control method of claim 8 , wherein the driving information is an image or a sound to be played back in a device connected to the tactile actuator, and

the determining of the driving mode comprises determining the driving mode in real time based on whether the image or the sound includes a preset image pattern or a preset audio pattern.