Nikon Corporation

Hidetsugu Takagi

Miho Matsumoto

Atsushi Sekine

Hitoshi Hatada

A microscope objective lens (OL) is constituted by a first lens group (G), a second lens group (G) having a positive refractive power, a third lens group (G) having a concave surface facing the image side, and a fourth lens group (G) having a concave surface facing the object side. The first lens group (G) is constituted by a plano-convex positive lens (L) having a flat surface facing the object side, and a negative lens (L) and satisfies the following conditional: 1.8<H/H<3.5 and 1.3<DLe/H<3.5, where: His the distance between the optical axis and the light ray most separated from the optical axis in the second lens group (G), from among light rays emitted from an object (OB) on the optical axis; His the distance between the optical axis and the light ray most separated from the optical axis at a lens surface on the image side of a final lens (Le); and DLe is the length of the final lens (Le) on the optical axis.

Microscope objective lens, microscope optical system, and microscope device

An ocular optical system including a Fresnel lens having a plurality of Fresnel zones formed on a lens surface on an observation object side, the plurality of Fresnel zones being arranged concentrically side by side along an aspherical surface having a shape which is rotationally symmetric with respect to a central axis of the Fresnel lens, the ocular optical system satisfying the conditional expression 0<PAE1/PAC1≤0.50, where PAE1 represents an average pitch in a radial direction of Fresnel zones formed in a portion having a radius of 15 mm or more from the central axis of the Fresnel lens, and PAC1 represents an average pitch in the radial direction of Fresnel zones formed in a portion having a radius of 15 mm or less from the central axis of the Fresnel lens excluding a first Fresnel zone.

Ocular optical system and head mounted display

An ocular optical system (EL) comprises, in order from an eye point (EP), a first lens group (G) having a positive refractive power and a second lens group (G) having a positive refractive power. The second lens group (G) includes a cemented lens having two optical members cemented together. A cemented surface of the cemented lens is a diffraction optical surface configuring a diffraction grating. A lens surface on one side in a lens constituting the first lens group (G) is a first Fresnel surface (FSa), and a lens surface on one side in the cemented lens of the second lens group (G) is a second Fresnel surface (FSb).

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Yokohama, Japan

Hidetsugu Takagi