Barco N.v.

Patrick Santy

Gerrit Verstraete

An automatic axial field compensation and quick-degauss control system is disclosed. Further, a CRT type monitor incorporating such an automatic compensation and quick-degauss control circuit, and a new degauss circuit are disclosed in accordance with the present invention. The compensation and quick-degauss control circuit relies upon three sensors to respectively detect and quantify the axial, lateral, and vertical components of a disturbing ambient magnetic field. The axial and lateral field component sensors have non-parallel axes of sensitivity such that the sum of values represented by the output signals from these sensors indicates the magnitude of the axial component of the disturbing field. Based upon this summation signal, the system applies a correction current to at least one correction coil. If more than one correction coil is employed, the coils are connected in series so that only one current need be generated to effect compensation. Outputs from all three of the sensors are involved in quick-degauss control. The third sensor is a vertical component sensor. The disclosed quick degauss system is different from the resonant types, it operates by a switched mode. Voltage over the degaussing coils is switched between a positive and negative voltage, which voltages are stored in large capacitors.

Growing community of inventors

Roeselare, Belgium

Patrick Santy