Optical disc tracking system with switching of tracking error signals at boundary between track guide and track address

A tracking system for an optical memory disc having a plurality of recording tracks thereon including track address regions and track information regions comprising:

• an optical head assembly including light beam producing means for producing a main light beam and two auxiliary light beams, said main and auxiliary beams being scanned over said plurality of tracks;
• detector means for detecting light beams reflected from said tracks as a result of said scanning and producing a first tracking error signal in response to the light reflected from said main beam and a second tracking error signal in response to the light reflected from said two auxiliary beams;
• and
• tracking control means for performing tracking control of said main beam on one of said tracks in response to said first tracking error signal at a boundary between a track address region and a track information region, and said second tracking error signal at track regions other than said boundary.