| 摘要 |
PURPOSE:To simplify an adjusting process and to improve the yield of products by comparing the level of a pilot signal reproduced from a recording medium and inputted through a deemphasis circuit and controlling the quantity of emphasis in the deemphasis circuit in accordance with the error signal between both the pilot signals. CONSTITUTION:When plural frequency levels, e.g. 2MHz and 0.5MHz, are used as pilot signals, the curves of emphasis characteristics can be simultaneously corrected and distortion or the like is reduced. When the quantity of deemphasis in the deemphasis circuit 15 is controlled, the transmission characteristics of the whole recording and reproducing system can be automatically corrected and the quantity of deemphasis in the deemphasis circuit 15 itself can be also automatically adjusted, so that it is unnecessary to adjust the deemphasis circuit individually. Even if dispersion in the characteristics of respective circuits or the influence or the like of temperature characteristics exists, the variation is practically absorbed and corrected by adjusting the quantity of deemphasis in the deemphasis circuit 15 to that the levels of pilot signals obtained before and after recording are equal. Consequently, non-adjustment can be practically attained and the yield of products can be improved.
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