A linear vibration motor is provided that includes a housing, a vibrator, a first shaft, and a second shaft. The vibrator vibrates along a first direction, and has a first through-hole and a space extending along the first direction. The first shaft and the second shaft, which are guides, are disposed along a second direction and are fixed to the housing so as to support the vibrator slidably along the first direction. In the linear vibration motor, the first shaft is fitted together by insertion into the first through-hole, and the second shaft is inserted into the space. The second shaft and part of a wall determining the space are in contact with each other in a third direction.

An ultrasound probe includes: a metal case including a bottom wall portion having a vibration surface, and a side wall portion connected to the bottom wall portion; a coil mounted on one surface of the side wall portion; and a magnet mounted in such a way as to sandwich the coil between the magnet and the one surface of the side wall portion, in which the coil causes an eddy current to occur in the one surface of the side wall portion, and causes the bottom wall portion to vibrate, by using a Lorentz force occurring in the side wall portion because of the interaction between the eddy current and a magnetic field generated by the magnet.

An ultrasound probe includes: a metal case including a bottom wall portion having a vibration surface, and a side wall portion connected to the bottom wall portion; a coil mounted on one surface of the side wall portion; and a magnet mounted in such a way as to sandwich the coil between the magnet and the one surface of the side wall portion, in which the coil causes an eddy current to occur in the one surface of the side wall portion, and causes the bottom wall portion to vibrate, by using a Lorentz force occurring in the side wall portion because of the interaction between the eddy current and a magnetic field generated by the magnet.

A linear vibration motor includes a housing with a first accommodation space, a vibration unit, an elastic part and a coil assembly fixed on the housing. The vibrating unit includes a support connected with the elastic part, and includes a top wall perpendicularly to a vibrating direction of the vibrating unit, a side wall bending and extending from a periphery of the top wall, a through hole penetrating the top wall, and two separation walls respectively bending and extending from the two opposite sides of the through hole. The top wall and the side wall enclose to form a second accommodation space which is divided by the two separation walls into a main accommodation space and two auxiliary accommodation spaces. The linear vibration motor further includes at least one weight block accommodated and fixed in the auxiliary accommodation spaces, and at least one magnet respectively fixed to the support.

The invention provides a vibration motor includes a housing, a vibrator in the housing, a stator accommodated in the housing, and a number of elastic parts suspending the vibrator in the housing. One of the vibrator and the stator includes a magnetic circuit system, and the other includes a coil. The elastic part is in an H shape, each has a first fixation part fixedly connected with the magnetic circuit system, and two second fixation parts perpendicularly extending from two opposite ends of the first fixation part. In addition, an interval is formed between the two second fixation parts. The second fixation parts and the first fixation part are fixedly connected with the housing. Therefore, the amount of parts of the vibration motor is reduced, the structure of the elastic part is simple, the machining and forming are simplified, and the cost is lower.

A mini subwoofer double drive low-frequency vibrator includes a base, an upper cover, a side cover, a flexible printed circuit, a coil, a magnetic body, a counterweight, a spring piece, an internal welding piece, an external welding piece, an insulating tape, and a buffer. The magnetic body and the coil includes a symmetrical double-driving structure at both upper and lower part to mutually offset components in a non-vibration direction of an electromagnetic force and cancel vibration noises. The spring piece adopts a V-shape structure to increase an effective length of a deformation zone and to make a response frequency even lower. Two V-shape springs are distributed symmetrically in a center, making an operation more stable. The buffer is adopted to enhance service life, for fear of a spring damage caused by high circuit voltage.

An electromagnetic drive device includes a permanent magnet attached to a surface of a first yoke facing a second yoke; and first and second excitation coils to generate magnetic flux when being energized. The second yoke includes a base, and a first protruding part protruding from the base toward the first yoke, between the first and second excitation coils. The permanent magnet includes a first region; and second and third regions positioned on respective sides of the first region. The first region is magnetized to be a first pole, and the second region and the third region are magnetized to be second poles. The first region is opposite to the first protruding part, a boundary between the first and second regions is opposite to the first excitation coil, and a boundary between the first and third regions is opposite to the second excitation coil.

An electromagnetic drive device includes a permanent magnet attached to a surface of a first yoke facing a second yoke; and first and second excitation coils to generate magnetic flux when being energized. The second yoke includes a base, and a first protruding part protruding from the base toward the first yoke, between the first and second excitation coils. The permanent magnet includes a first region; and second and third regions positioned on respective sides of the first region. The first region is magnetized to be a first pole, and the second region and the third region are magnetized to be second poles. The first region is opposite to the first protruding part, a boundary between the first and second regions is opposite to the first excitation coil, and a boundary between the first and third regions is opposite to the second excitation coil.

A vibration generating device includes a housing; a diaphragm supported by the housing, and configured to generate sound by vibrating in a first direction; and a vibration providing part attached to the housing, and configured to vibrate the housing. The vibration providing part vibrates the housing in the first direction at a first frequency, and vibrates the housing in a second direction at a second frequency lower than the first frequency.

A linear vibration motor and a linear vibration system include a housing, a moving member, a drive unit including a driving coil and driving magnets, and a bias unit including a biasing electromagnet and biasing magnets. The moving member vibrates in a first direction substantially orthogonal to a winding axis of the driving coil with Lorentz force generated by a magnetic field formed by the driving coil and a magnetic field formed by the driving magnets. The biasing electromagnet and the biasing magnets are disposed such that the same poles substantially face each other, and the moving member is biased in the first direction by a magnetic spring generated from a repulsive force between the biasing electromagnet and the biasing magnets. Moreover, a magnetic spring constant of the magnetic spring varies with variation in a value of a current flowing through a biasing coil.