Patent ID: 6268671
Filing Date: 2001-07-31
Classification: H02K

Abstract:
A vibration generation apparatus comprising:a vibratory assembly comprising a coil and a yoke, the yoke providing a magnetic circuit, wherein the vibratory assembly is configured to vibrate in at least one mode of vibration and the at least one mode of vibration includes generating at least one shock;a driving mechanism supplying the coil with rectangular-pulse drive current of a constant peak value to vibrate the vibratory assembly such that the amplitude of the vibration corresponds to the duration of the rectangular pulse;a control mechanism varying the frequency of the rectangular pulse-drive current supplied by the driving means and the duration of the rectangular pulse independently of each other;a columnar plunger which cooperates with the yoke in providing the magnetic circuit and which is slidably received in the vibratory assembly; andurging means comprising a protrusion formed on the yoke so as to oppose an end of the plunger and magnetized in a polarity opposite to that of the end of the plunger, whereby the plunger and the protrusion are urged away from each other.