An observation apparatus includes: an illumination optical system that radiates illumination light into a container from outside the container; an objective lens that collects signal light from a cell in the container; a detection optical system that detects the signal light collected by the objective lens; and a retroreflective member that has an array of a plurality of small reflective components, is disposed across from the illumination optical system with the container interposed therebetween, and reflects the illumination light transmitted through the container.

An apparatus includes a kinematic nest that supports an element having a spherical surface, a rotation mechanism that rotates the element, and processor that activates the rotation mechanism.

An apparatus includes a kinematic nest that supports an element having a spherical surface, a rotation mechanism that rotates the element, and processor that activates the rotation mechanism.

A state visualizer according to one aspect of the present disclosure includes an optical member including a fixed part that has a fixed relative positional relationship with an object to be measured and a movable part that is movably supported by the fixed part and keeps a constant angle with respect to a gravity direction, the optical member retroreflecting a light or an electromagnetic wave in a case where the fixed part and the movable part are in a predetermined positional relationship. The optical member changes an intensity of the light or the electromagnetic wave reflected in a retroreflection direction in accordance with a change of a relative positional relationship between the fixed part and the movable part.

A state visualizer according to one aspect of the present disclosure includes an optical member including a fixed part that has a fixed relative positional relationship with an object to be measured and a movable part that is movably supported by the fixed part and keeps a constant angle with respect to a gravity direction, the optical member retroreflecting a light or an electromagnetic wave in a case where the fixed part and the movable part are in a predetermined positional relationship. The optical member changes an intensity of the light or the electromagnetic wave reflected in a retroreflection direction in accordance with a change of a relative positional relationship between the fixed part and the movable part.

An imaging system is provided. The imaging system includes a display including a first display half screen and a second display half screen, a retroreflective device provided on the display, a first beam splitter facing the first display half screen, a second beam splitter facing the second display half screen, a first optical shutter located on a surface of the first beam splitter, and a second optical shutter located on a surface of the second beam splitter.

An imaging system is provided. The imaging system includes a display including a first display half screen and a second display half screen, a retroreflective device provided on the display, a first beam splitter facing the first display half screen, a second beam splitter facing the second display half screen, a first optical shutter located on a surface of the first beam splitter, and a second optical shutter located on a surface of the second beam splitter.

A reflector arrangement for position determination and/or marking of target points, comprising a retroreflector and a first sensor arrangement, by means of which the orientation measurement radiation passing through the retroreflector is acquirable. The first sensor arrangement comprises a first optical assembly providing a fisheye lens, and a first sensor, wherein the retroreflector and the first sensor arrangement are arranged in such a way that orientation measurement radiation passing through the retroreflector is projectable onto the detection surface of the first sensor by means of the first optical assembly.

A reflector arrangement for position determination and/or marking of target points, comprising a retroreflector and a first sensor arrangement, by means of which the orientation measurement radiation passing through the retroreflector is acquirable. The first sensor arrangement comprises a first optical assembly providing a fisheye lens, and a first sensor, wherein the retroreflector and the first sensor arrangement are arranged in such a way that orientation measurement radiation passing through the retroreflector is projectable onto the detection surface of the first sensor by means of the first optical assembly.

An apparatus includes a kinematic nest that supports an element having a spherical surface, a rotation mechanism that rotates the element, and processor that activates the rotation mechanism.