Cathode ray tube astigmatism correction apparatus.

摘要

Apparatus for correcting astigmatism produced by the electromagnetic deflection yoke of a cathode-ray-tube includes stigmator electrodes provided with elongated slots through which the cathode-ray-tube's electron beam or beams pass. Appropriate correction voltages, stored in digital memory, are applied to the stigmator and focus electrodes for bringing about re-focusing of the electron beam in appropriate axes for restoring a single point focus.