| 摘要 |
A reproducing power control unit of a magneto-optical recording and reproducing apparatus comprising level detecting means, composed of a diode, a capacitor, a subtractor and a sample hold circuit, for detecting the signal levels of control marks of different lengths on a magneto-optical disk, control data generating means, composed of a divider, for outputting a comparing result between the signal levels, error reference generating means, composed of a CPU and a ROM, for generating a reference value representing a specific relation between the signal levels when a light beam has an optimal reproducing power, reference comparing means, composed of a subtractor, for comparing the comparison result with the reference value, and reproducing power changing means, composed of an operational amplifier and a transistor and a resistor, for changing the reproducing power of the light beam to approximate the comparison result to the reference value. The reproducing power is controlled in such a manner that the relation between the signal levels of various types of marks each having a different length becomes equal to the specific relation represented by the reference value. Accordingly, an aperture which minimizes noise components such as crosstalk is developed, and the probabilities of readout errors are reduced.
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