| 摘要 |
For a multi-scan display having a single S-capacitor incorporated, a S-distortion correcting circuit capable of correcting S distortion at any horizontal scanning frequency. The S-distortion correcting circuit comprises a first circuitry for cancelling out horizontal S-distortion making appearance in dependence on geometrical relation between scanning locus of an electron beam and the plane of screen of a picture tube, a second circuitry for cancelling out horizontal S-distortion generated in a horizontal scanning circuit in inverse proportion to the second power of the horizontal scanning frequency and an auxiliary deflection coil. The outputs of the first and second circuitries are added together. A current supplied to the auxiliary deflection coil is so controlled that a signal representing the result of the addition substantially coincides with a feedback signal from the auxiliary deflection coil. Thus, the first circuitry makes available the S-distortion correcting quantity independent of the horizontal scanning frequency, while the second circuitry cancels out a correction quantity of the S-capacitor which is proportional to the second power of the horizontal scanning frequency, whereby the correction of the S-distortion by the S capacitor is essentially cancelled out with only the correction by the first circuitry being rendered effective. The S-distortion correction is made possible independent of the horizontal scanning frequency.
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