Optical reader system for data stored on optical disc

摘要

The optical reader has a source (210) of light polarised into components P and S. One of these components is transmitted onto the reflective surface of the optical disc (250) and the other component is reflected. An optical device with a quarter wavelength plate (230) faces the light source to change the component of polarisation of the light passing through it. A second optical device also has a quarter wavelength plate (264) to change the polarisation of the light passing through it, and a plate (262) to reflect incident light . The detector (270) and the second optical device are placed facing each other on either side of the optical reader.