Optical information recording/reproducing apparatus

An optical information recording/reproducing apparatus comprising:

• optical means for converging laser beams from a laser light source on an optical disc formed with guide tracks;
• first focus control means for focusing a laser beam on a guide track on said optical disc;
• second focus control means for focusing the laser beam on a surface of a substrate of said optical disc;
• and
• high frequency component detection means for detecting a high frequency component in excess of a reference value from reflection of the laser beam which is focused on the surface of said optical disc substrate, said high frequency component detection means producing an output signal having a level which is representative of detection of contaminants on the surface of said optical disc.

An optical information recording/reproducing apparatus for recording/reproducing information on or from an optical disc formed with guide tracks, comprising:

• optical means for converging laser beams from a laser light source on said optical disc;
• focus control means for focusing a laser beam on a guide track on said optical disc;
• recording means for modulating and recording information;
• reproducing means for receiving reflection of a focused laser beam to produce a signal;
• and
• test signal detection means for detecting a test signal containing predetermined frequency components from the output signal delivered out of said reproducing means,
• said test signal being recorded on a specified track and containing at least two frequency components, said test signal detection means detecting a difference between amplitudes of said two frequency components to detect contaminants on the surface of said optical disc in accordance with the difference.