Abstract: A microscope objective includes three groups that are in a positive-negative-positive configuration. The first lens group includes a plurality of cemented lenses, and includes, closest to the object, a meniscus lens having its concave surface on the object side. The second lens group includes a first meniscus lens component having its concave surface on the image side and a second meniscus lens component having its concave surface on the object side. At least one of the lens components of the third lens group is a cemented lens.

Abstract: A microscope tube lens that forms an enlarged image of an object by being combined with an infinity-corrected objective, the tube lens including in an order from an object side: a first lens group that has positive power and that includes a cemented lens; a second lens group that has negative power; and a third lens group that has positive power. A following condition expression is satisfied, where NA is a numerical aperture on an image side of the tube lens, FN is a field number of the tube lens, and ? is an airy disk diameter with respect to d line (588 nm) of the tube lens: 0.04<NA; and 1700?FN/?.

Abstract: A microscope tube lens that forms an enlarged image of an object by being combined with an infinity-corrected objective, the tube lens including in an order from an object side: a first lens group that has positive power and that includes a cemented lens; a second lens group that has negative power; and a third lens group that has positive power. A following condition expression is satisfied, where NA is a numerical aperture on an image side of the tube lens, FN is a field number of the tube lens, and ? is an airy disk diameter with respect to d line (588 nm) of the tube lens: 0.04<NA; and 1700?FN/?.

Abstract: A microscope objective includes three groups that are in a positive-negative-positive configuration. The first lens group includes a plurality of cemented lenses, and includes, closest to the object, a meniscus lens having its concave surface on the object side. The second lens group includes a first meniscus lens component having its concave surface on the image side and a second meniscus lens component having its concave surface on the object side. At least one of the lens components of the third lens group is a cemented lens.

Abstract: A tube lens for a microscope includes, in the order from an object, a first lens group that has positive power and that includes a cemented lens, a second lens group that has negative power, and a third lens group has positive power. The tube lens satisfies the following condition expressions, where NA is a numerical aperture on an image side of the tube lens, FN is a field number of the tube lens, and ? is an airy disk diameter with respect to d line of the tube lens (588 nm): 0.04<NA; and 1700?FN/?.

Abstract: A relay optics includes a positive first lens group, a positive second lens group, and a positive third lens group. The second lens group includes, closest to the object, a lens having the concave surface facing toward the object. The relay optics is configured in such a manner that a light flux passing between the second and third lens groups is a substantially-parallel light flux, and satisfies condition expressions below, where f1 represents the focal length of the first lens group, d1 represents the length from the primary image to a surface closest to the object in the first lens group, f12 represents the combined focal length of the first and second lens groups, and exp12 represents the length from an exit pupil position of an optics consisting of the first and second lens groups to a surface closest to the object in the second lens group: 1?f1/d1?4.3 0.16?exp12/f12?1.2.

Abstract: A relay optics includes a positive first lens group, a positive second lens group, and a positive third lens group. The second lens group includes, closest to the object, a lens having the concave surface facing toward the object. The relay optics is configured in such a manner that a light flux passing between the second and third lens groups is a substantially-parallel light flux, and satisfies condition expressions below, where f1 represents the focal length of the first lens group, d1 represents the length from the primary image to a surface closest to the object in the first lens group, f12 represents the combined focal length of the first and second lens groups, and exp12 represents the length from an exit pupil position of an optics consisting of the first and second lens groups to a surface closest to the object in the second lens group: 1?f1/d1?4.3 0.16?exp12/f12?1.2.

Abstract: A tube lens for a microscope includes, in the order from an object, a first lens group that has positive power and that includes a cemented lens, a second lens group that has negative power, and a third lens group has positive power. The tube lens satisfies the following condition expressions, where NA is a numerical aperture on an image side of the tube lens, FN is a field number of the tube lens, and ? is an airy disk diameter with respect to d line of the tube lens (588 nm): 0.04<NA; and 1700?FN/?.