Patent ID: 7542399

Claim:
An optical reading device capable of detecting spherical aberration caused by a storage medium comprising: a light source for providing light to access data stored in a storage medium; a diffractive optical element (DOE) disposed in an optical path between the light source and the storage medium for diffracting the light provided by the light source and thereby generating light having different phases; a polarization beam splitter (PBS) disposed in an optical path between the DOE and the storage medium for splitting light; a reflective mirror for reflecting light sent from the PBS; a sensor for receiving first light generated by the DOE and reflected by the storage medium and second light generated by the DOE and reflected by the reflective mirror via the PBS, and for measuring optical signals of the first light and the second light; an adjusting device disposed in an optical path between the PBS and the storage medium for adjusting light sent from the PBS to the storage medium; and a control circuit coupled to the sensor and the adjusting device for updating settings of the adjusting device based on the optical signals measured by the sensor.