| 摘要 |
<p>[PROBLEMS] A magnetic sensing device for reliably sensing come-off of a needle with a simple structure. [MEANS FOR SOLVING PROBLEMS] A magnetic sensing device comprises a magnet for sensing an object, a magnetic bias magnet, a magnetic sensor, a control unit, a reset unit, a storage unit, and a warning unit. In response to a start signal sent from the reset unit, the control unit allows the magnetic sensor to measure the intensity of the magnetic field in an initial environment and the intensity of the magnetic field at regular time intervals, allows initial magnetic field intensity storage means of the storage unit to store therein the intensity of the magnetic field in the initial environment, allows computing means to compute a warning range in which a warning is issued from the intensity of the magnetic field in the initial environment and a threshold stored in threshold storage means of the storage unit and to send the warning range to comparing means, allows the comparing means to compare the intensity of the magnetic field measured at the regular time intervals with the warning range and to send a warning signal to the warning unit if the measured intensity of the magnetic field is over the warning range, and allows the warning unit to issue a warning of come-off of a needle in response to the warning signal.</p> |
