Abstract: A three-dimensional position observation apparatus provided with a lens system having focusing and diaphragm mechanisms, for forming an image on an imaging plane by light from an observation object includes a beam steering member disposed in a light path extending from the observation object to the imaging plane, for changing a traveling direction of observation light into a plurality of different directions, and an image analyzing unit for analyzing a position of the observation object based on a positional relation between a plurality of images on the imaging plane formed by light passing through the beam steering member.

Abstract: A three-dimensional position observation apparatus provided with a lens system having focusing and diaphragm mechanisms, for forming an image on an imaging plane by light from an observation object includes a beam steering member disposed in a light path extending from the observation object to the imaging plane, for changing a traveling direction of observation light into a plurality of different directions, and an image analyzing unit for analyzing a position of the observation object based on a positional relation between a plurality of images on the imaging plane formed by light passing through the beam steering member.

Abstract: A dark field microscope is capable of providing illumination with a long focal distance condenser lens having a low numerical aperture without the need for a diaphragm for an objective lens. A method is provided for effectively adjusting its optical axis. In particular embodiments, the dark field microscope includes; a light source for emitting illumination light; a light collecting optical system including a light collecting side condenser lens for collecting the illumination light from the light source to illuminate an observation sample; and an image forming optical system including an objective lens for receiving scattered light from the observation sample to form a magnified image of the sample, the light collecting side condenser lens is a long focal distance lens, and a light shielding member for shielding the illumination light is provided on a back focal plane or at an image forming center of it in the image forming optical system.

Abstract: A three-dimensional position observation apparatus provided with a lens system having focusing and diaphragm mechanisms, for forming an image on an imaging plane by light from an observation object includes a beam steering member disposed in a light path extending from the observation object to the imaging plane, for changing a traveling direction of observation light into a plurality of different directions, and an image analyzing unit for analyzing a position of the observation object based on a positional relation between a plurality of images on the imaging plane formed by light passing through the beam steering member.

Abstract: [Summary] [Object] To provide a dark field microscope capable of providing illumination even with a long focal distance condenser lens having a low numerical aperture without the need for a diaphragm for an objective lens, and a method for effectively adjusting its optical axis. [Means for Settlement] In a dark field microscope including: a light source for emitting illumination light; a light collecting optical system including a light collecting side condenser lens for collecting the illumination light from the light source to illuminate an observation sample; and an image forming optical system including an objective lens for receiving scattered light from the observation sample to form a magnified image of the sample, the light collecting side condenser lens is a long focal distance lens, and a light shielding member for shielding the illumination light is provided on a back focal plane or at an image forming center of it in the image forming optical system.

Abstract: A three-dimensional position observation apparatus provided with a lens system having focusing and diaphragm mechanisms, for forming an image on an imaging plane by light from an observation object includes a beam steering member disposed in a light path extending from the observation object to the imaging plane, for changing a traveling direction of observation light into a plurality of different directions, and an image analyzing unit for analyzing a position of the observation object based on a positional relation between a plurality of images on the imaging plane formed by light passing through the beam steering member.