Abstract: A fixation sight apparatus for an ophthalmological instrument is disclosed. It has a unique arrangement including light source and mirrors for presenting a plurality of fixation mark images on a measuring optical axis. An eye to be tested selectively fixedly gazes at the most clearly sightable one among the plurality of fixation mark images according to the sight confirmation characteristic thereof.

Abstract: An eye fundus camera including an illuminating optical system having a photographing light source such as a xenon lamp, and a photographing optical system having an image forming lens and a photographing film plane. A light measuring system is provided and includes a half mirror disposed in the photographing optical system to reflect a part of light passing through the photographing system, the reflected light being received by a photodetector. The signal from the light measuring system is used to control the operation of the xenon lamp to thereby control the exposure. The light measuring system includes a variable aperture device conjugate with the film plane, the aperture device having a plurality of apertures of different diameters so that the field of measurement of light can be changed in accordance with the photographing field.

Abstract: An optical adapter for a light-wave rangefinder comprising a light emitting means for emitting a distance measuring light wave modulated by a predetermined modulation frequency, and a light receiving means for receiving a reflecting light wave reflecting from a target point to which the distance measuring light wave is directed, wherein a time delay between the distance measuring light wave and the reflecting light wave is utilized to determine the distance to the target point, the optical adapter comprising at least one photoconduction means for conducting distance measuring light wave and the reflecting light wave, and at least one single objective optical means for projecting the distance measuring light wave from the photoconduction means towards the target point, for condensing the reflecting light wave reflecting form the target point and for guiding the light wave to the photoconduction means.

Abstract: Inclination measuring instrument having a tube having a concave inside surface and filled with liquid so as to have a bubble, a first electrode provided on the outside surface of the tube opposite to the bubble, second and third electrodes provided on the outside surface of the tube opposite to the first electrode and located along the direction of shift of the bubble, a guard electrode provided on the outside surface of the tube to frame the first, second and third electrodes and to be supplied with a predetermined voltage, and processing means for connecting a first capacitor consisting of the first and second electrodes and second capacitor consisting of the first and third electrodes so as to calculate the inclination of the tube from the output of the first and second capacitors.

Abstract: An eyefundus camera including an observing and photographing optical system having a focusing lens, a mark projecting optical system for projecting a plurality of mark images on patient's eyefundus. The mark projecting optical system is interconnected with the focusing lens of the observing and photographing optical system. There is provided a focusing signal detecting device including a photoelectric device for photoelectrically scanning the mark images projected on the fundus of the patient's eye to produce mark image signals, a horizontal synchronizing signal counting circuit for counting horizontal synchronizing signals for the photoelectric means, a mark image counting circuit for counting number of the mark image signals to determine that a predetermined number of mark image signals exist in a single scanning line, an operation circuit responsive to outputs of the two circuits for determining a horizontal scanning line which is used for judgement of focus conditions.

Abstract: Exposure control system for ophthalmic photographing apparatus including a focusing mark projecting optical system for projecting focusing mark on a patient's eye so that the focusing condition can be clearly recognized. A detector is provided for detecting the intensity of the light from the mark image. The signal from the detector is used to control the exposure control system by for example determining the time in which the photographing light source is energized.

Abstract: Binocular microscope having a pair of converging optical paths, each including a magnification changing optical device which comprises two or more lens groups. The lens groups are rotatably mounted on the lens housing so that they can be alternately brought into alignment with the optical path for changing the magnification power.

Abstract: An apparatus is provided comprising a slit illumination system for projecting a slit illumination light along a slit axis, and a recording optical system including a taking lens and an image plane, said taking lens having an optical axis intersecting at an angle with a plane containing said slit illumination light, said taking lens further having a major plane which includes a line of intersection of said plane of slit illumination light with said image plane. Also provided are means for supporting said slit illumination system and said recording optical system as a unit for rotation about said slit axis so that orientation of the slit illumination light can be changed as desired.