FALL DETECTION DEVICE, MAGNETIC DISK DEVICE, AND PORTABLE ELECTRONIC APPARATUS

摘要

By detecting that a differentiation value of the absolute value of acceleration is lower than a negative threshold value DAth1 in a negative direction from a first stage (S1: Stationary state) where the differentiation value of the absolute value of acceleration is approximately 0, it is considered that the stage is in a second stage (S2: Fall start state). When the absolute value of acceleration after that has become lower from a threshold value Ath1, it is considered that the fall detection device has entered a third stage (S3: Low gravity state). When the low gravity state has continued for a given time T3, it is considered that the stage is in a fourth stage (S4: Falling state), and a fall detection signal is output. Thus, the processing load when the determination is performed by software is reduced and the prediction of a fall can be performed.