摘要 |
A method is provided for determining the magnitude of flatness deviation in high density information discs, such as video discs, manifesting irregularities in playback. Such flatness deviations are known as "orange-peel." A stylus riding over a relatively large area (4-5 grooves) of the disc surface provides a vertical velocity signal within a given spatial or temporal frequency band. The signal in velocity or displacement form is the quantitative measure of deviation. The method is useful for other type discs where quantitative measurements in flatness deviation are desired.
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