| 摘要 |
PROBLEM TO BE SOLVED: To continuously correct raster distortion at low cost by controlling a winding current of a coil placed for cancelling a magnetic field of a horizontal linearity coil, so as to control an inductance of the horizontal linearly coil thereby improving the horizontal linearity on a screen. SOLUTION: A horizontal operating frequency of an FH-V conversion circuit is digitized, based on a horizontal synchronizing signal received by a receiver. A variable linearity control circuit provides an output of a control signal, to provide optimum linearity to a variable linearity coil drive circuit, based on an FH-V voltage and a SIZE signal controlling a horizontal deflection size. The inductance of variable linearity coils L1, L2 inserted in series with a horizontal deflection coil LY is changed by canceling the magnetic flux to improve the distortion of a horizontal deflection current. The variable linearity coils L1, L2 are inserted to a horizontal output circuit, so that their saturation characteristics have polarities opposite to each other. |
