| 摘要 |
A technique is provided for very efficiently injecting DC current into a horizontal deflection yoke to achieve raster shifting. The DC current (which is bi-directional) is used to unbalance the scan current, thereby providing a means to shift the horizontal scan raster to the left and right. This ability makes it is possible to offset symmetry problems in the yoke and CRT gun system. The amount of current and the direction of the current is both user adjustable and system adjustable, and is controlled through a microcontroller. Preferably, the microcontroller uses an H-synchronized clock generated by an on-screen display (OSD) controller, thereby avoiding the need to separately generate a high frequency clock. Using a current switching approach, low power losses are achieved in a circuit that is low cost and requires few components.
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