Patent ID: 7946375

Claim:
A seat belt retractor to be installed in a vehicle comprising: an electric motor; a spool capable of winding a seat belt for occupant restraint in association with a driving of the electric motor; and a controller for controlling the electric motor, wherein a starting condition is defined by a state of the seat belt relative to a vehicle occupant and a state of a vehicle door corresponding to the seat belt, wherein, in cases where the starting condition is satisfied, the controller is configured to control the electric motor to rotate in a belt winding direction such that a motor output of the electric motor is varied according to a satisfaction pattern of the starting condition, wherein the satisfaction pattern comprises the state of the seat belt being changed from a worn state to a released state and the state of the vehicle door corresponding to the seat belt when the state of the seat belt is changed from the worn state to the released state, and wherein, in cases where the starting condition is satisfied, the controller is configured to control the electric motor to rotate in the belt winding direction at a first motor output sufficient to rotate the spool in response to a first satisfaction pattern and to rotate in the belt winding direction at a second motor output larger than the first motor output in response to a second satisfaction pattern.