SEAT BELT DEVICE

摘要

A retractor (10) comprises a spindle (12) for winding a seat belt, a frame (11) for supporting the spindle (12) rotatably, a winding spring (130) for urging rotation of the spindle (12) in the winding direction of seat belt, and a magnetic disc (150) and a magnetic sensor unit (160) for detecting rotation of the spindle (12). The magnetic disc (150) and the magnetic sensor unit (160) are arranged between the frame (11) and the winding spring (130) composed of a magnetic material, respectively. With such an arrangement, rotation of the spindle can be detected with high reliability while suppressing the impact of disturbance magnetic field.