Olympus Optical Company, Ltd.

Isamu Misawa

Akira Matsueda

In an apparatus for reproducing digital information recorded on a track in an optical record medium as discrete record portions representing bit '1' signals in the digital information, main and sub-reading light beams are projected on the optical record medium such that the sub-reading light beam is situated on the same track as that on which the main reading light beam is situated, but is shifted forwardly with respect to the main reading light beam relative to the scanning direction. The main and sub-reading light beams reflected by the optical record medium are photo-electrically converted into main and sub-reproduced signals, respectively. Peaks of the sub-reproduced signal are detected to derive a peak signal, and then the amplitude and offset of the peak signal are adjusted to produce a threshold signal. Alternatively, an average of the sub-reproduced signal is detected to derive an average value signal and the amplitude and offset of the average signal are adjusted to produce a threshold signal. The main and sub-reproduced signals are supplied to a voltage comparator to derive a bivalent signal which represents the recorded digital information.

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Okaya, Japan

Isamu Misawa