| 摘要 |
Improved fluorescent light collection efficiency and sensitivity are provided while suppressing an increase in the size of an objective lens. An objective lens (17) is configured so as to have a convex lens portion (26) in the central portion and a truncated conical cylindrical body (27) on the periphery of the convex lens portion (26). Therefore, of the fluorescent light emitted from a sample (16), the fluorescent light (b) having a large radiation angle that is not incident on the convex lens portion (26) can be completely reflected by the outer peripheral surface (27b) of the cylindrical body (27) and collected, thereby enabling light having a large radiation angle, which cannot be collected by a conventional convex lens, to be collected. As a result, a highly sensitive fluorescent light information reading device can be realized in which fluorescent light collection efficiency can be improved while suppressing an increase in the size of the objective lens, and in which S/N deterioration caused by the presence of undetected fluorescent light blocked by the prism (20) can be prevented. |
