Abstract: A photographing unit for a microscope has a photometric detector to measure brightness of light from a sample and includes a changing member which changes a brightness of light toward an observation system and a control unit which controls the light based on a detection output of the photometric detector. In addition, the changing member can be controlled based on the presence of an observer. A shielding member can be provided that automatically shields an optical path of the observation system. An illumination system for an index on a reticle can be provided so that the illumination of the reticle can be performed or extinguished at desired times. Additionally, the color of light with which the index is illuminated may be made distinguishable from the color of light from a sample, and the contrast of the index to the sample can be controlled.

Abstract: A photographing unit for a microscope has a photometric detector to measure brightness of light from a sample and includes a changing member which changes a brightness of light toward an observation system and a control unit which controls the light based on a detection output of the photometric detector. In addition, the changing member can be controlled based on the presence of an observer. A shielding member can be provided that automatically shields an optical path of the observation system. An illumination system for an index on a reticle can be provided so that the illumination of the reticle can be performed or extinguished at desired times. Additionally, the color of light with which the index is illuminated may be made distinguishable from the color of light from a sample, and the contrast of the index to the sample can be controlled.

Abstract: This invention relates to a focal position detection apparatus for detecting a positional shift between the imaging position of an object image formed by a predetermined objective optical system and the detection surface of the object image. This apparatus includes a beam splitter for extracting part of a light beam from the objective optical system, splitting the light beam into at least three light beams, and guiding the split light beams to the light-receiving surface of a photo-sensing device arranged at a predetermined position. This beam splitter guides at least the three split light beams to a standard optical path and a pair of reference optical path and forms a standard image at a predetermined position in the standard optical path and a pair of reference images at predetermined positions in the pair of optical paths, respectively.

Abstract: In a focusing apparatus, a beam of light from a light beam source is imaged on an object to be inspected through one half of the pupil of an imaging optical system and a reflected beam of light from the object to be inspected passes through the other half of the pupil. The object to be inspected and the imaging optical system are moved relative to each other to effect focusing. A light divider divides the reflected beam of light from the object to be inspected into first and second reflected beams of light which are received by first and second light receiving members, respectively. A light intercepting member intercepts the reflected beam of light from the back of the object to be inspected, which is included in the second reflected beam of light. A controller moves the object to be inspected and the imaging optical system relative to each other on the basis of the outputs of the first and second light receiving members.

Abstract: An apparatus for detecting a rotation operation of revolver is provided with a rotation direction detecting device for detecting a rotation direction of revolver by detecting a displacement of a position indication portion indicating a position of objective mount portion. In case that the rotation of revolver is carried out either in a manual manner or in an automatic manner, an address of mount hole in revolver which is to be next located at the predetermined position may be determined at start of rotation operation of revolver.