| 摘要 |
<p>An objective lens of an optical pickup apparatus converges a divergent light flux onto an information recording surface. The following conditional formula is satisfied: verbar;dgr;SA1/dgr;Uverbar; bull; verbar;dgr;Uverbar; + verbar;dgr;SA2/dgr;Tverbar; bull; verbar;dgr;Tverbar; le; 0.07 lgr;rms where lgr; represents a wavelength of a light source, dgr;SA1/dgr;U represents a change of a spherical aberration for an object-to-image distance change dgr;U (verbar;dgr;Uverbar; le; 0.05 mm) and dgr;SA2/dgr;T represents a change of spherical aberration for a temperature change dgr;T (verbar;dgr;Tverbar; le; 30C), the object-to-image distance is a distance between the light source (a light emitting point) and the information recording surface.</p> |
