Patent ID: 6940794

Claim:
An information recording/reproducing apparatus for recording information on an information recording medium having one or two recording layers and for reproducing the information recorded on the information recording medium, comprising: a light source for emitting a first light beam having a predetermined light power P pre ; a determination section for determining whether the information recording medium has one recording layer or two recording layers; a light beam transmission adjustment section for adjusting the quantity of the first light beam transmitted therethrough based on a determination result of the determination section; and a light condensing section for condensing the first light beam transmitted through the light beam transmission adjustment section on the information recording medium, wherein when the determination section determines that the information recording medium has one recording layer, the light beam transmission adjustment section adjusts the predetermined light power P pre so as to be a first light power P 1 , when the determination section determines that the information recording medium has two recording layers, the light beam transmission adjustment section adjusts the predetermined light power P pre so as to be a second light power P 2 , and the predetermined light power P pre , the first light power P 1 , and the second light power P 2 satisfy the relationship of P 1 <P 2 ≦P pre .