Optical head device for recording/reproduction for recording medium using plural light spots

An optical head device in which the recording on or reproduction from a recording medium having a recording film on a surface of a transparent substrate is made using a plurality of light spots, comprising:

• a first laser source for emitting a first laser beam having a wavelength .lambda..sub.1 ;
• a second laser source for emitting a second laser beam having a wavelength .lambda..sub.2 different from the wavelength .lambda..sub.1 ;
• one objective lens used commonly to said first and second laser beams to converge said first and second laser beams on a recording surface of the recording film of said recording medium through said transparent substrate;
• a focusing control system for moving said objective lens in the direction of an optical direction to focus said first laser beam as a light spot on said recording surface;
• recording medium discriminating means for discriminating plural kinds of recording mediums having transparent substrates which have different refractive indices, respectively;
• and
• light spot displacing means for displacing, when at least one of said plural kinds of recording mediums is discriminated by said recording medium discriminating means, a light spot position of said second laser beam in a direction in which the amount of deviation of the light spot position of said second laser beam on the recording surface in the optical-axis direction caused by a difference of the refractive index of the discriminated recording medium from that of another recording medium is cancelled.