Abstract: A zoom lens system which includes a first lens unit having negative refractive power, a second lens unit having positive refractive power and a third lens unit having positive refractive power, and is configured to change a magnification from a wide-angle position to a telephoto position by moving the second lens unit along an optical axis on the object side and moving the third lens unit along the optical axis in which said second lens unit consists of four lens elements including, in order from the object side, two positive lens elements and a negative lens element, and which can be focused by moving a third lens unit, and in which each lens unit is thin and which is thin as a whole, and an image pickup apparatus which uses this zoom lens system and has a shallow depth.

Abstract: The invention relates to an electronic image pickup system whose depth dimension is extremely reduced, taking advantage of an optical system type that can overcome conditions imposed on the movement of a zooming movable lens group while high specifications and performance are kept. The electronic image pickup system comprises an optical path-bending zoom optical system comprising, in order from its object side, a 1-1st lens group G1-1 comprising a negative lens group and a reflecting optical element P for bending an optical path, a 1-2nd lens group G1-2 comprising one positive lens and a second lens group G2 having positive refracting power. For zooming from the wide-angle end to the telephoto end, the second lens group G2 moves only toward the object side. The electronic image pickup system also comprises an electronic image pickup device I located on the image side of the zoom optical system.

Abstract: An image pickup apparatus comprising a first lens unit which comprises at least a negative lens element and at least a positive lens element and has negative refractive power, a second lens unit which has positive refractive power, and an optical path bending reflecting optical element which has a variable reflecting surface disposed in an airspace between a most object side lens component of the first lens unit and a most object side lens component of the second lens unit. This image pickup apparatus changes a magnification by moving the second lens unit along an optical axis and corrects a deviation of an image location by varying a shape of the variable reflecting surface of the reflecting optical element.

Abstract: A zoom lens system which includes a first lens unit having negative refractive power, a second lens unit having positive refractive power and a third lens unit having positive refractive power, and is configured to change a magnification from a wide-angle position to a telephoto position by moving the second lens unit along an optical axis on the object side and moving the third lens unit along the optical axis in which said second lens unit consists of four lens elements including, in order from the object side, two positive lens elements and a negative lens element, and which can be focused by moving a third lens unit, and in which each lens unit is thin and which is thin as a whole, and an image pickup apparatus which uses this zoom lens system and has a shallow depth.

Abstract: A stereoscopic microscope comprising a uniaxial optical system consisting of an objective lens system and a vari-focal optical system which is coaxial with the objective lens system, and at least a pair of observation optical systems, wherein right and left optical axes of the observation optical systems pass through locations different from that of an optical axis of the uniaxial optical system and wherein the uniaxial optical system comprises a positive lens component made of an extraordinary dispersive optical material.

Abstract: A stereoscopic microscope comprising an objective lens system and a variable magnification optical system which are disposed coaxially with each other in addition to an eyepiece optical system, and configured so as to permit stereoscopic observation of an image of an object by leading, to right and left eyes of an observer by way of the eyepiece optical system, rays having passed through portions apart from optical axes of the objective lens system and the variable magnification optical system. This stereoscopic microscope has a length as measured from the observer's eyes to the object to be observed which is shortened by disposing at least two reflecting members in the variable magnification optical system for bending an optical path in the variable magnification optical system.

Abstract: A stereoscopic microscope comprising an objective lens system and a variable magnification optical system which are disposed coaxially with each other in addition to an eyepiece optical system, and configured so as to permit stereoscopic observation of an image of an object by leading, to right and left eyes of an observer by way of the eyepiece optical system, rays having passed through portions apart from optical axes of the objective lens system and the variable magnification optical system. This stereoscopic microscope has a length as measured from the observer's eyes to the object to be observed which is shortened by disposing at least two reflecting members in the variable magnification optical system for bending an optical path in the variable magnification optical system.

Abstract: A stereoscopic microscope having right and left eyepiece lens systems for observation of two aerial images formed with parallax. The stereoscopic microscope comprises a main body housing and an eyepiece body housing which comprises an optical system ranging to aerial images formed at locations nearest the observer's eyes and eyepiece lens systems including transmission type light diffusing devices which are disposed in the vicinities of the aerial images formed at the locations nearest the observer's eyes, thereby permitting enlarging the exit pupils and performing stereoscopic observation with little fatigue.

Abstract: A stereoscopic endoscope including an objective lens system for forming an image of an object which objective lens system is arranged at the front end of an inserting section and has a single optical axis; an image transmission device coaxially arranged with the objective lens system and adapted to transmit the image formed by the objective lens system; a pupil dividing device for dividing the image transmitted through the objective lens system and the image transmission device so as to obtain left and right images of the object; an image sensing device for picking up the left and right images obtained by the pupil dividing device; a first support structure containing at least the objective lens system; and a second support structure containing at least the pupil dividing device and the image sensing device, wherein the first and second support structures are rotatable relative to each other around an axis extending along the longitudinal dimension of the endoscope.

Abstract: A stereoscopic endoscope including an objective lens system for forming an image of an object which objective lens system is arranged at the front end of an inserting section and has a single optical axis; an image transmission device coaxially arranged with the objective lens system and adapted to transmit the image formed by the objective lens system; a pupil dividing device for dividing the image transmitted through the objective lens system and the image transmission device so as to obtain left and right images of the object; an image sensing device for picking up the left and right images obtained by the pupil dividing device; a first support structure containing-at least the objective lens system; and a second support structure containing at least the pupil dividing device and the image sensing device, wherein the first and second support structures are rotatable relative to each other around an axis extending along the longitudinal dimension of the endoscope.

Abstract: A surgical microscope system having a stereoscopic optical system, an imaging unit, and a monitor display. The stereoscopic optical system has two optical paths and forms a 3D image of an object. The imaging unit forms two images of the object from two light beams focused in the optical paths. The monitor display displays the images of the object which the imaging unit has formed. The surgical microscope system further comprises an observation-light receiving section located in the optical paths for determining an observation field, an observation-light emitting section located in the monitor display for applying the images formed by the imaging unit, and reflectors arranged between the observation-light receiving section and the observation-light emitting section. The observation-light receiving and the observation-light emitting sections are located close to each other and a barrel holds the sections together.

Abstract: A three-dimensional vision endoscopic apparatus according to the present invention comprises a pair of optical systems for transmitting an image of a subject as two subject images having a parallax between them, a pair of imaging devices for picking up subject images transmitted by the optical systems, at least one visual field mask, a display unit for displaying the two subject images alternately or concurrently, an adjusting mechanism for adjusting the position of one or both of the imaging devices so that the display images will become consistent on the screen of the display unit, and an adjusting mechanism for adjusting the relative position of the visual field mask.

Abstract: A stereomicroscope includes an objective optical system, a variable magnification optical system, and a plurality of imaging optical systems, in which the plurality of imaging optical systems can be moved in a plane perpendicular to the optical axis of the variable magnification optical system. Thus, the stereomicroscope has the advantage that where one of two observers wishes to observe a brighter image, the amount of light can be adjusted, without replacement of a light source, by moving the imaging optical systems.

Abstract: A stereomicroscope comprising an objective lens, an afocal vari-focal optical system disposed coaxially with the objective lens, a pair of right and left imaging optical systems for imaging parallel rays emerging from the afocal vari-focal optical system, and right and left eyepiece lens systems for magnifying images which are formed by the right and left imaging optical systems.This stereomicroscope permits observing images with adequate stereoscopic impressions and can be relatively compact owing to a fact that the microscope satisfies the following condition (1):0.005 .ltoreq.AD.multidot..beta./f.sub.0 .ltoreq.0.

Abstract: A stereomicroscope includes an objective lens for converting light from an object into parallel beams, an imaging lens for forming an image of the object, a prism for erecting the object image, and an eyepiece for observing the object image so that the object image is viewed stereoscopically through the eyepiece, in which the eyepiece is constructed from a single lens system equipped with a variable magnification optical system and an eye lens whose diameter is larger than a viewer's interpupil distance, and optical paths from the object image to the viewer's eyes traverse the positions outside the optical axis of the eyepiece. Thus, the stereomicroscope dispenses with the need for adjustment of the interpupil distance, causes the freedom of the eyepoint to be increased, and allows a viewer to observe the image from any direction whatsoever.

Abstract: A stereomicroscope is equipped with an objective lens, a variable magnification optical system having an optical axis common with that of the objective lens, a splitting optical system splitting emergent light from the variable magnification optical system into a plurality of optical paths, and an eyepiece disposed in at least one of the optical paths, having a diameter larger than the interpupil distance of an observer. Thus, the stereomicroscope has advantages that, with a simple structure and easy adjustment, many people can make observations, the mountings of photographic and TV devices are possible, the directions in which plural observers see through the microscope can be changed, and eyestrain is difficult to occur which may be caused by the difference in magnification between the images of a bilateral observation optical system.

Abstract: A stereomicroscope is equipped with an objective lens, a variable magnification optical system having an optical axis common with that of the objective lens, a splitting optical system splitting emergent light from the variable magnification optical system into a plurality of optical paths, and an eyepiece disposed in at least one of the optical paths, having a diameter larger than the interpupil distance of an observer. Thus, the stereomicroscope has advantages that, with a simple structure and easy adjustment, many people can make observations, the mountings of photographic and TV devices are possible, the directions in which plural observers see through the microscope can be changed, and eyestrain is difficult to occur which may be caused by the difference in magnification between the images of a bilateral observation optical system.

Abstract: An objective lens system for the rays within the ultraviolet region comprising, in the order from the object side, a first lens unit which has a positive refractive power, and comprises a meniscus lens component having a strongly concave surface on the object side and at least two cemented lens components, and a second lens unit which has a positive refractive power and comprises at least two cemented lens components, all the lens elements composing said objective lens system being made of optical materials having, when they are 5 mm thick, internal transmittance of at least 50% for a ray having a wavelength of 300 nm.