TILT CORRECTING DEVICE

PROBLEM TO BE SOLVED: To obtain a tilt correcting device capable of correcting the relative tilt between an information medium and a a head at a low cost. SOLUTION: In the tilt correcting device correcting the tilt between an information medium having a surface structure capable of generating an amplitude fluctuation in the difference signal of reflected lights and a head forming a light spot on the information medium, this device is provided with a photodetector 15 receiving lights reflected from the optical spot, means obtaining the difference signal of outputs of the photodetector 15 and tilt control means controlling the relative tilt between the information medium and the head so that an index approaches the extremun while using the amplitude of the obtained difference signal as the index.