Patent ID: 7196989

Claim:
An optical recording medium driving device for recording and/or reproducing signals for at least two sorts of optical recording media having respective different values of the recording and/or reproducing power, comprising: an optical head for emitting a light beam on said optical recording medium; an optical coupling efficiency varying device configured to vary the optical coupling efficiency which is the ratio of the light volume of a light beam condensed on said optical recording medium to the light volume of a light beam emitted by said optical head; an optical coupling efficiency controlling device configured to control the optical coupling efficiency varying device; said optical coupling efficiency controlling device configured to control said optical coupling efficiency varying device depending on the sort of the optical recording media; and a temporal relationship controller configured to control a temporal relationship between a first timing of changing the optical coupling efficiency and a second timing of changing the light volume of light condensed on a recording surface of said optical recording medium, wherein said optical coupling efficiency varying device including an optical path branching device configured to branch an input light beam into at least two optical paths, and the ratio of branching of the light volume to said least two optical paths is varied to vary the optical coupling efficiency.