MAGNETIC BODY DETECTOR

• Main Authors: MASUBUCHI SHINICHI, UCHIDA HIROSHI
• Format: Patent
• Language: English
• Published: 04.02.2010
• Subjects: DETECTING MASSES OR OBJECTS; GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; MEASURING; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To provide a magnetic body detector which performs appropriate notification to a user, as a means of performing notification to prevent a magnetic body from being attracted by a strong magnet of an MRI diagnostic device, by arithmetic operation for inhibiting a detection value of a magnetic body which does not pass through a gate. SOLUTION: A plurality of magnetic sensors are provided in the front, rear, left and right of the gate to enhance the sensitivity of detection of a change in magnetic flux density, and their AC signal components are calculated and DC variation of each magnetic sensor is removed. In-phase signal components generated by a remote magnetic body are calculated/removed, calculation is performed by using the ratio of the signals of the magnetic sensors arranged in the front and back to inhibit magnetic bodies which do not move in the gate direction, a coefficient is calculated from in-phase signal components on the left and right basis to inhibit magnetic bodies which pass the outside of the gate, integration calculation is performed after absolute value calculation of the differences in the magnitude and variation time of peak values due to differences in the direction of movement and moving speed, and thereby, only a magnetic body in the vicinity which passes through the gate is regarded as a target for detection. COPYRIGHT: (C)2010,JPO&INPIT