COMPATIBLE TRACKING CONTROL METHOD, AN OPTICAL PICKUP AND AN OPTICAL RECORDING AND/OR REPRODUCING DEVICE, SPECIALLY RELATED TO COMPATIBLY TRACKING-CONTROLLING VARIOUS KINDS OF OPTICAL INFORMATION STORAGE MEDIA WITHOUT CHANGING A STRUCTURE OF THE EXISTING DEVICE

PURPOSE: A compatible tracking control method, an optical pickup and an optical recording and/or reproducing device are provided to emit 3 beams capable of being commonly used for information storage media having different track pitches through an optical pickup, so that a controller can compatibly tracking-control different kinds of information storage media by using signals for the 3 beams. CONSTITUTION: A light radiated from a light source is separated into a main beam(M), the first sub beam(S1), and the second sub beam(S2) by a diffracted optical element. The main beam(M), the first sub beam(S1), and the second sub beam(S2) are radiated on optical information storage media(40,41), so that distances 'D' between the main beam(M) and the first sub beam(S1) and between the main beam(M) and the second sub beam(S2) can be within a range obtained by using a common multiple of different track pitches. The main beam(M), the first sub beam(S1), and the second sub beam(S2) reflected from any one of the optical information storage media(40,41) are detected. Each tracking error signal is detected by using detection signals of the main beam(M), the first sub beam(S1), and the second sub beam(S2).