APPARATUS FOR CONTROLLING MAGNETIC FIELD INTENSITY Russian patent published in 2002 - IPC

FIELD: magneto-optic systems for storing information, namely, control of magnetizing with use of bias winding in such systems for storing information. SUBSTANCE: apparatus includes first controller, second controller, digital-analog converter, electric current shaper and bias winding. First controller detects position of focal spot of objective and transmits respective data to second controller for forming signal related with said position. Digital-analog converter converts digital signal to exciting voltage and applies said voltage to electric current shaper for applying to bias winding electric current related with exciting voltage. Bias winding forms magnetic field whose intensity depends upon magnetizing electric current. Second controller takes into account magnetic leakage fields at forming digital signal. Magnetic leakage may have constant or variable intensity depending upon position of objective, circumferential or linear velocity of information carrier. Apparatus may have in addition electric current pickup for measuring magnetizing electric current and feedback circuit for applying to electric current shaper feedback voltage related with magnetizing electric current. EFFECT: uniform magnetic field, lowered leakage power. 4 cl, 12 dwg