Optical disk and apparatus for reproducing signal without crosstalk

An apparatus for reproducing signal recorded on an optical disc, said optical disc comprising a signal recording track spirally formed on the surface of the optical disc;

• information pits formed on said signal recording track;
• and a plurality of non-signal regions periodically formed on said signal recording track wherein no information pit is formed in the non-signal regions and each of the plurality of non-signal regions comprises a mirror-finished surface and is positioned out of alignment with at least one non-signal region out of two non-signal regions formed on both inner and outer neighboring tracks in a radial direction of the optical disc, said apparatus comprising:
• means for irradiating a light beam onto the surface of said optical disc;
• means for detecting a light beam reflected by the surface of said optical disc and producing an electrical signal;
• means for storing the electrical signal and simultaneously and synchronously outputting stored electrical signals of a plurality of neighboring tracks;
• means for converting frequency characteristics of the electric signals in accordance with individually-alterable converting coefficients;
• means for adding the electrical signals to output a sum signal as a reproduction signal;
• means for detecting said non-signal regions;
• and
• means for setting the converting coefficients of said frequency characteristics converting means in accordance with the reproduction signal when the non-signal region is detected.