Patent ID: 7170832

Claim:
An optical scanning device for scanning an information layer by means of a radiation beam in a writing mode and a reading mode, the device comprising: a radiation source for emitting said radiation beam, an objective lens having an optical axis, for converging said radiation beam so as to form a scanning spot in the position of said information layer, and a scanning spot power switch arranged in the optical path of said radiation beam, for switching the light power of said scanning spot between a first light power level at the writing mode and a second, lower light power level at the reading mode, characterized in that said scanning spot power switch is further arranged for switching the size of the cross-section of said radiation beam between a first size at the writing mode and a second, larger size at the reading mode so as to switch the rim intensity of said radiation beam between a first rim intensity level at the writing mode and a second, higher rim intensity level at the reading mode, thereby switching the light power of said scanning spot between said first light power level at the writing mode and said second light power level at the reading mode.