| 摘要 |
An optical device compatible with at least three different types of information carrier. It comprises a main optical branch comprising detecting means (203), a collimator (201), a first beam splitter (214) at a first distance dl from the collimator, a second beam splitter (224) at a second distance d2 from the collimator and a third beam splitter (234) at a third distance d3 from the collimator. It also comprises, located substantially perpendicular to the main optical branch - a first optical branch for scanning an information carrier with a first numerical aperture NA1; the first optical branch comprises a first radiation source (211), a first pre-collimator (212) and the first beam splitter (214); - a second optical branch for scanning an information carrier with a second numerical aperture NA2; the second optical branch comprises a second radiation source (221), a second pre-collimator (222) and the second beam splitter (224); - a third optical branch for scanning an information carrier with a third numerical aperture NA3; the third optical branch comprises a third radiation source (231), a beam shaper (232) and the third beam splitter (233); In this optical scanning device, dl >d2>d3 and NA2<NA 1 <NA3. |
