| 摘要 |
An immersion microscope objective which has a magnification of about 60, an NA of 1.4, and a reduced number of constituent lens elements and yet which is satisfactorily corrected for spherical and axial chromatic aberrations and is also superior in the flatness of the image field. The objective has a 1-st lens unit (G1) having a positive refractive power as a whole and including a cemented lens having a cemented surface which is concave toward the object side, a 2-nd lens unit (G2) having a positive refractive power as a whole, a 3-rd lens unit (G3) including a cemented lens composed of a negative lens, a positive lens, and a negative lens, in order from the object side toward the image side, a 4-th lens unit (G4) of positive refractive power, a 5-th lens unit (G5) having a convex surface directed toward the object side at a position closest to the object side, and a concave surface directed toward the image side at a position closest to the image side, and a 6-th lens unit (G6) having a concave surface directed toward the object side at a position closest to the object side, and a convex surface directed toward the image side at a position closest to the image side.
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