| 摘要 |
The present invention relates to a dual acceleration sensor system usable for detecting impact, when strong impact works on a mobile device, and recording a history of applied impact, and workable with a low power consumption. It contains low range and high range acceleration sensors (1, 2), a signal processing circuit (4), and/or an operation mode controller (5) for switching signal between the two sensors and an operation mode of the signal processing circuit (4). The operation mode controller (5) switches between a low range mode in which a signal from the low range acceleration sensor (1) is processed at a low range operation rate and a high range mode in which a signal from the high range acceleration sensor (2) is processed at a high range operation rate. It is judged whether data processed in the low range mode exceeds a first threshold or not, and if not, the low range mode continues, while the mode switches to the high range mode if it does. In the high range mode, when a state that the data is less than a second threshold continues for a predetermined period of time, the mode returns to the low range mode, and if not, the high range mode remains. |
