Optical recording and reproducing apparatus and method

A method for recording and/or reproducing data into and/or from a first recording medium into or from which data is recorded or reproduced using a light of a first wavelength, and a second recording medium into or from which data is recorded or reproduced using a light of a second wavelength, by focusing the light of the first or second wavelength onto the first or second recording medium by a focusing means, comprising the steps of:

• disposing off the optical axis of the focusing means a first means for generating a light of the first wavelength;
• disposing on the optical axis of the focusing means a second means for generating a light of the second wavelength;
• correcting a coma aberration in the light of the first wavelength and guiding the corrected light along the optical axis of the focusing means;
• detecting the light of the first or second wavelength reflected from the first or second recording media;
• and
• incorporating the first and the second light generating means in a single package.

An optical head for recording and/or reproducing data into and/or from a first recording medium into or from which data is recorded or reproduced using a light of a first wavelength and a second recording medium into or from which data is recorded or reproduced using a light of a second wavelength, comprising:

• a means of focusing a light of a first or second wavelength onto a first or second recording media;
• a first means disposed off the optical axis of the focusing means to generate a light of the first wavelength;
• a second means disposed on the optical axis of the focusing means to generate a light of the second wavelength;
• a means of correcting a coma aberration in the light of the first wavelength and guiding the corrected light along the optical axis of the focusing means;
• and a means of detecting the light of the first or second wavelength reflected from the first or second recording media;
• and
• means for incorporating the first and second light generating means in a single package.