Double-quadrupole DAF gun for self-converging color CRTs

The authors have developed a novel dynamic astigmatism and focus (DAF) gun for high-resolution tubes, called the dynamic-quadrupole DAF gun, which gives better round spots than existing DAF guns. This has been achieved by using an additional quadrupole lens adjacent to the triode part driven commonly by the same DAF dynamic voltage. Thus, the problem of the elliptically distorted spot-shape still remaining in the DAF gun has been solved. With the new gun a much rounder spot is obtained over the entire screen under a high-resolution tube condition, improving the horizontal resolution and reducing risks of moire appearance while maintaining the self-convergence.<
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