The present disclosure relates to a linear vibrator, and more particularly to a small-sized linear vibrator having a structure capable of generating a great vibratory force, outputting various types of vibrations in broadband and accurately coupling a magnet.
Generally, a linear vibrator is employed for generating vibration in electronic appliances, such as mobile phones, gaming machines, portable information terminals or the like, using electromagnetic force between a magnet and a coil. Particularly, the linear vibrator is variably used to haptic devices due to high demand on tactility. Recently, as devices using a trembler are diversified and miniaturized, a small-sized linear vibrator capable of generating a large vibration volume is greatly demanded.
A conventional linear vibrator is such that when a current is applied to a coil, operation of the vibrator is initiated by electromagnetic force formed between the coil and the magnet to vertically vibrate the trembler in association with elasticity of a spring.
However, the conventional linear vibrator has a disadvantage in that vibration thereof can be felt only in the vicinity of resonant frequency. A trembler according to the conventional linear vibrator is such that one resonant frequency exists in a 100˜300 Hz band, and a moving distance and vibration volume reach a peak value in a limited range near the resonant frequency, wherefrom the vibration can be felt by a man.
It is understood that vibration volume felt by a man in the haptic devices is over 0.1 G, a frequency band from which vibration can be well detected by a man is generally in the range of 100˜300 Hz, and a frequency band detectable in sound is in the range of 20 Hz to 20,000 Hz.
Meanwhile, a mobile terminal using haptic technology largely uses a linear vibrator whereby miniaturization can be realized and tactility can be provided when a button on a touch screen is depressed. The linear vibrator needs an additional member such as a weight to increase vibration volume due to limit of the vibration volume. The limit of vibration volume is mainly solved by a method of using a peak value in the resonant frequency, in relation to limit of vibration volume and vibratory force in the linear vibrator.
Due to the fact that a difference of fine frequency can be detected at about 10 Hz in the resonant frequency band, only one vibration can be felt in the haptic devices.
Therefore, there is a disadvantage in the conventional linear vibrator in that it is difficult to realize various vibratory feelings through frequency variation due to the fact that the vibration range mainly felt by a man is limited to near 10 Hz when a touch screen is touched.
In case of broadening an actually usable frequency band (i.e., usable band from which vibratory force exceeding approximately 0.1 G detectable by a man can be generated) for generating various types of vibrations, vibrations having a broadened range of resonant frequency must be generated. However, due to the limit of size of linear vibrator and limit of vibratory force, the conventional linear vibrator cannot help but use vibrations of a narrow region near the resonant frequency.
In addition, the conventional linear vibrator is disadvantageous in that there is no means to centralize a position of a magnet in a yoke coupling the magnet, such that it is difficult to centralize the magnet in the coupling process. In case the magnet is not centrally and accurately positioned in the yoke, an unfavorable vibration may be generated due to mass center of vibration not being centrally positioned on the yoke, and an impediment to accurate control of vibration may be generated.
The present disclosure is disclosed to solve the abovementioned disadvantages in whole or in part, and it is an object of the present disclosure to provide a linear vibrator capable of generating vibrations in a broad range deviated from resonant frequency and having a structure capable of generating a high vibratory force in a broad band to allow detecting various vibrations.
It is another object of the present disclosure to provide a linear vibrator capable of outputting in a frequency band generating a sound and various vibrations through a structure capable of providing a high vibratory force.
It is still another object of the present disclosure to provide a linear vibrator capable of providing an accuracy and rapidity in coupling process of vibrator.