Abstract: A focusing method for a zoom lens system, including at least two lens groups, enables a portion of the zoom lens system to function as a focusing lens group over the entire focal length constituted by discrete focal length ranges. The portion of the zoom lens system, functioning as the focusing lens group, is changed to another portion thereof, in accordance with to the discrete focal length ranges.

Abstract: A zoom lens system includes at least three lens groups. Zooming is performed by moving at least two lens groups. The first lens group and the second lens group are formed as the focus-adjusting lens groups which are movable in the optical-axis direction for performing the narrower zoom adjustment when the zoom lens system is being assembled.

Abstract: An endoscope system is provided with a light guide including a plurality of optical paths, and a low-coherent light source that emits a low-coherent light beams. The low-coherent light source is provided at a proximal end side of the light guide. The light beams emitted by the low-coherent light source are incident on the plurality of optical paths, respectively. The endoscope system is further provided with an interferometer unit.

Abstract: An endoscope system which can obtain a tomographic image in accordance with optical coherence tomography (OCT). An OCT section of the endoscope system comprises a first optical fiber, a second optical fiber, an optical coupler, a super-luminescent diode (SLD), a photodetector, and a reference mirror. The first optical fiber is opposed to the SLD at its proximal end. The second optical fiber is opposed to the photodetector at its proximal end. The optical coupler establishes optical connection between the optical fibers. The reference mirror is arranged movable in front of the distal end of the second optical fiber. The distal end of the first optical fiber is introduced to an OCT scanning unit at a tip of an endoscope. This OCT scanning unit includes a polygon mirror having a plurality of reflecting surfaces, which are tilted in different angles from each other. The OCT scanning unit forms a plurality of scanning lines aligned in parallel over a subject at regular intervals.

Abstract: A high zoom-ratio zoom lens system includes a positive first lens group, a negative second lens group, a positive third lens group, and a negative fourth lens group. Zooming is performed by moving each of the lens groups along the optical axis.

Abstract: A zoom lens system includes a movable-positive first lens group, a movable-negative second lens group, a movable-positive third lens group, and a movable-positive fourth lens group. Upon zooming from the short to the long focal length extremities, all the lens group are arranged to move in a manner that the distance between the first lens group and the second lens group increases, the distance between the second lens group and the third lens group decreases, the distance between the third lens group and the fourth lens group increases, and the distance between the first lens group and the third lens group does not change. Upon zooming from the short to the long focal length extremities, the fourth lens group first moves toward the image and thereafter moves toward the object in a U-turn path.

Abstract: A zoom lens system includes a first lens group, a second lens group, a third lens group, and a fourth lens group. Zooming is performed by moving each of the first through fourth lens groups in the optical axis direction, and the zoom lens system satisfies the following conditions: 1.1<f23T/f23W<1.8  (1) 0.2<LD23W/fw<0.45  (2) 0.01<(D23W−D23T)/fT<0.

Abstract: A zoom lens system, covering a wide-angle range, includes a negative first lens group, a positive second lens group, and a negative third lens group.

Abstract: A zoom lens system includes a negative first lens group, a positive second lens group, and a positive third lens group. Upon zooming from the short to long focal length extremities, the distance between the first and second lens groups decreases, and the distance between the second and third lens groups increases.

Abstract: A zoom lens system includes a movable positive first lens group, a movable negative second lens group, a movable positive third lens group, and movable or stationary positive fourth lens group. Upon zooming, the distance between the first and second lens groups is increased; the distance between the second and the third lens groups is decreased; and the distance between the third and the fourth lens groups is increased.

Abstract: A fiber bundle for image transmission includes pluralities of first optical fibers and a plurality of second optical fibers. Both pluralities of optical fibers being tied at their distal ends to form a composite bundle portion. The first optical fibers being tied at their proximal ends to form a first branched bundle portion and the second optical fibers being tied at their proximal ends to form a second branched bundle portion.

Abstract: A zoom lens system includes a positive first lens group, and a negative second lens. Zooming is performed by varying the distance between the first lens group and the second lens group. The first lens group includes a negative first sub lens group and a positive second sub lens group. The zoom lens system satisfies the following conditions: 5.0<ft/f1<7.0  (1) 0.9<|fw/f1a|<1.8  (2) wherein ft designates the focal length of the entire zoom lens system at the long focal length extremity; f1 designates the focal length of the first lens group; fw designates the focal length of the entire zoom lens system at the short focal length extremity; and f1a designates the focal length of the first sub lens group of the first lens group.

Abstract: An endoscope system capable of obtaining a normal light image and/or fluorescent light image is further provided with an a low-coherent light source arranged on a proximal end side of one of first and second light guides. A scanning unit is provided to cause the low-coherent light beam emerged from a tip of the first light guide to scan on the object. The low-coherent light reflected by the object is directed to the first light guide by the scanning unit as detecting light. A mirror is provided to reflect the low-coherent light beam emerged from a tip of the second light guide. A detector is arranged on a proximal end side of the other of the first and second light guides to detect interference fringe pattern generated by interference between the detecting light and the reference light.

Abstract: A stereoscopic endoscope includes a primary optical system for transmitting a luminous flux, reflected by an object located near a first end of the optical system, to a second end of the optical system. A first image forming system forms a first image of the object in accordance with a first area of the luminous flux, and a second image forming system forms a second image of the object in accordance with a second area of the luminous flux, the second area not overlapping the first area. An imaging device detects the first image and the second image, the image detecting system outputting an image signal.

Abstract: A zoom lens system includes a first lens group, a second lens group, a third lens group, and a fourth lens group.

Abstract: A zoom lens system includes a positive first lens group, a positive second lens group, a diaphragm, and a negative third lens group. The first through third lens groups move in an optical axis direction for zooming. The positive first lens group includes a negative lens element, and at least one positive lens element. The negative lens element is positioned at the most object-side of the positive first lens group, and is provided with a concave surface on the object-side surface thereof.

Abstract: An endoscope system is provided with a normal light image capturing system, a fluorescent light image capturing system, and an OCT (Optical Coherence Tomography) image capturing system. The normal light image, the fluorescent light image and the OCT image are displayed on a screen of a display device simultaneously. Optionally, one of the normal light image or the fluorescent light image is displayed as an animated image, and the OCT image is also displayed as an animated image. A cursor indicating a scanning position corresponding to the OCT image is indicated on one of the normal light image and the fluorescent light image displayed as the animated image.

Abstract: A fiber bundle for image transmission includes pluralities of first optical fibers and a plurality of second optical fibers. Both pluralities of optical fibers being tied at their distal ends to form a composite bundle portion.

Abstract: An endoscope system is provided with first and second light guides, which are optically coupled by an optical coupler. A low-coherent light source is provided, and the light emitted therefrom is incident on the first or second light guide. Further provided is a scanning unit that causes the light beam emerged from the first light guide to scan on a predetermined surface of the object. The light beam reflected by the object is directed, by the scanning unit, to the first light guide as a detection light beam. A light beam emerged from the second light guide is reflected by a reflector and returned to the second light guide as a reference beam. By varying the optical path length of the reference beam relative to that of the detection beam, two beams interfere. A signal processing system generates OCT image based on the signal detected by a light detecting device which receives the interfering beams.

Abstract: An illumination optical system includes a luminous body, and an illumination lens element through which light rays from said luminous body is diffused and emitted. The illumination lens element has peaks and troughs alternately provided on an incident surface or an exit surface thereof. A cross-sectional shape of the peaks and troughs is a curved surface defined by a periodic function which can be differentiated, or the peaks and troughs are formed by a plurality of straight lines approximating the curved surface.