| 摘要 |
<p>A 3-beam-generating grating (2), a collimating lens (3), a polarizing beam splitter (4), a mirror (5), and an object lens (6) are arranged sequentially in the optical path between a semiconductor laser element (1) and an information recording medium (7). The reflective side of the polarizing beam splitter (4) has a reflection characteristic such that the reflectance is minimum for return light (L2) at an angle of incidence of 45 degrees whereas the reflectance increases as the angle of incidence of the return light (L2) deviates from 45 degrees. This realizes an optical head device that is not likely to cause the decrease in tracking error signal if the object lens shifts in radial directions of the recording medium.</p> |
