US Patent 9467033 Vibration motor and mobile terminal having the same

A vibration motor includes a housing, a coil, a moving portion, an elastic member and a roller member. The housing has a top surface, a bottom surface, and first to fourth side surfaces joining the top surface to the bottom surface, the first to fourth surfaces defining an inner circumferential surface of the housing. The coil is provided in the housing. The moving portion provided in the housing and the moving portion is configured to reciprocate between the first and third sides arranged opposite to each other. The elastic member is provided between the moving portion and the housing. The roller member is provided in the housing and arranged to come into rolling contact with the top or bottom surface of the housing.