Abstract: A portable single lens microscope that provides structure between the eye and the microscope slide, preferably including a single lens having an aperture optimized to attain the best image resolution, preferably including a focus mechanism, preferably including a slide holding and moving mechanism, and preferably including a slide position locking mechanism, or any combination of these structures and mechanisms. Methods are disclosed for determining an optimum aperture size for a single lens microscope (and other uses) including a lens of any type, and methods are disclosed for designing a single lens microscope lens system that provides superior image quality. A single lens microscope according to the present invention can provide substantial and unexpected imaging benefits over previous single lens microscopes and compound microscopes.

Abstract: A rough motion shaft 54 and a fine motion shaft 55 are provided on a front side of a stage 37 with respect to an optical axis of an observation optical system of a microscope. Further, a rough motion shaft 45 and a fine motion shaft 46 are provided on a rear side with respect to the optical axis. The rough motion shaft 54 and the fine motion shaft 55 are linked with the rough motion shaft 45 and the fine motion shaft 46 so as to move objective lenses 43 selectively in rough motion or fine motion. Objective lenses 43A, 43B are arranged in a circular shape on a fixing member 111 and a rotating member 113 is provided for rotating these objective lenses 43A, 43B along the direction of the arrangement. This rotating member 113 is provided with a weight 123 and this weight 123 applies a rotation force in inverse direction larger than a rotation force by a rotating body comprised of the rotating member 113 and the objective lenses 43A, 43B depending on a rotation angle of the rotating member 113.

Abstract: A microscope according to the invention comprises an aberration correcting objective lens facing a specimen and having an aberration correcting lens correcting an aberration due to an error in the thickness of a cover, a Petri dish or a slide glass; a moving amount detector detecting moving amount of the aberration correcting lens; a focusing unit moving the specimen; a driver unit driving the focusing unit; and an arithmetic unit obtaining a defocus amount based on a moving amount detected by the moving amount detector. When the aberration correcting lens is moved, the specimen is put out of focus. On the basis of a defocus amount obtained by the arithmetic unit, the driver unit drives The focusing unit so that the lens may focus on the specimen.

Abstract: A beam splitting optical system for an automatic focusing apparatus includes a telescopic system having an objective optical system and a viewing optical system, a beam splitter which splits object-carrying light transmitted through the objective optical system from the telescopic optical system by a splitter surface, and a focus detection optical system having a pair of light receivers which receive beams of the object-carrying light split by the splitter surface. The focus detection optical system is arranged so that beams of the object-carrying light to be respectively received by the light receiver are incident upon the splitter surface of the beam splitter at different incident angles. The transmittance and reflectance of the splitter surface of the beam splitter is not uniform in distribution and changes depending on the incident angle of the object-carrying light incident thereupon.

Abstract: This invention provides an angled-dual-axis confocal scanning microscope comprising a fiber-coupled, angled-dual-axis confocal head and a vertical scanning unit. The angled-dual-axis confocal head is configured such that an illumination beam and an observation beam intersect optimally at an angle &thgr; within an object. The vertical scanning unit causes the angled-dual-axis confocal head to move towards or away from the object, thereby yielding a vertical scan that deepens into the object, while keeping the optical path lengths of the illumination and observation beams unchanged so to ensure the optimal intersection of the illumination and observation beams in the course of vertical scanning. The angled-dual-axis confocal scanning microscope may further comprises a transverse stage, causing the object to move relative to the angled-dual-axis confocal head along transverse directions perpendicular to the vertical direction, thereby producing a transverse scan.

Abstract: A microscope system has an objective unit including an objective lens, an objective holding device for holding the objective lens so that the objective lens can be spatially moved, at least one actuator for driving the objective lens, and an outer frame member for integrally supporting the objective lens, the objective holding device, and the actuator. Thus, an optical apparatus which is small in size, low in cost, and high in resolution can be obtained.

Abstract: A position adjusting means is provided at an outer periphery of an objective lens opposite to an observation sample and the observation sample is moved by the position adjusting means in an optical axis direction of the objective lens to set a focal point of the objective lens to the observation sample.

Abstract: A beam splitting optical system for an automatic focusing apparatus includes a telescopic system having an objective optical system and a viewing optical system, a beam splitter which splits object-carrying light transmitted through the objective optical system of the telescopic optical system by a splitter surface, and a focus detection optical system having a pair of light receivers which receive beams of the object-carrying light split by the splitter surface. The focus detection optical system is arranged so that beams of the object-carrying light to be respectively received by the light receivers are incident upon the splitter surface of the beam splitter at different incident angles. An optical element is provided in a light path of at least the larger quantity of beams of the object-carrying light, among those to be received by the pair of light receivers so as to reduce the quantity of light to be transmitted therethrough.

Abstract: There is disclosed a microscope causing a variable-magnification optical system provided in the optical path of the microscope and having at least an optical member movable in the direction of optical axis of the optical path, to vary the magnification of the observed image of the specimen, a rotary knob for moving the optical member in the direction of optical axis, a position indicating device for indicating when the rotary knob is in a rotary position where the optical member is in a predetermined position and a varying device for varying the predetermined position.

Abstract: A beam splitting optical system for an automatic focusing apparatus includes a telescopic system having an objective optical system and a viewing optical system, a beam splitter which splits object-carrying light transmitted through the objective optical system from the telescopic optical system via a splitter surface, and a focus detection optical system having a pair of light receivers which receive object-carrying light beams split by the splitter surface. The focus detection optical system is arranged so that the object-carrying light beams to be received by the light receivers are incident upon the splitter surface of the beam splitter at different incident angles. The splitter surface is coated with a thin metal coating.

Abstract: A stereoscopic microscope comprises a body tube provided with an objective lens, a base provided with a stage on which a sample as an object to be observed is mounted, a guide mechanism for driving the body tube to change a distance between the body tube and the sample for conducting a focusing operation, a focus driving unit for transmitting the driving force to a movable portion of the guide mechanism, and a focus operating unit which can be operated externally for giving the driving force to the focus driving unit in order to drive the guide mechanism. The guide mechanism is placed on one end of the base, the focus driving unit is placed inside the base, and the focus operating unit is placed on the other end of the base.

Abstract: A microscope unit of the present invention having a supplementary lens by means of which the distance between a view object and the viewing end of a microscope is adjustable. The unit has an intermediate member which is attachable between the microscope viewing end and the supplementary lens and has a dimension in the direction of the optical axis, where a first engagement part which is detachably fastenable to a lens attachment part at the microscope viewing end and a second engagement part which is detachably fastenable to the supplementary lens are formed in the intermediate member.

Abstract: The invention describes a focusing drive for optical instruments that has, in addition to a pinion (1) and toothed rack arrangement (1, 2), slide rods (4) as guidance means for continuously changing the relative position of optical assemblies with respect to one another. The toothed rack (2) has a plurality of support elements (3) that are arranged—for example in angled fashion—on either side of its longitudinal extent. The support elements (3) are designed so that they have a shallow S-shape in cross section. In addition, they are dimensioned in such a way that they touch the contact surface of the one housing module (5) only with their planar end regions (3a). The result is a resilient or flexing motion upon actuation of the pinion (1), thus achieving smooth and zero-backlash adjustment.

Abstract: A microscope suitable for use together with MRI, and a support stand for the microscope are provided. A microscope 1 is a non-magnet type where any electric motor is not used, and hence does not induce fluctuations of magnetic field having effects on image quality of an MRI 3 by focusing or zooming. Hence, the microscope of the invention is suitable for use together with MRI 13. Since a clutch C is of non-magnet type, a support stand 2 does not induce changes in the surrounding magnetic field environments if the clutch is operated, and hence it is suitable for use, for example, in proximity to the MRI.

Abstract: An apparatus and method for efficiently observing a biochemical substance with focusing accurately and rapidly on the substance disposed on an inside of a container is provided. A focusing mark, which is used as a reference when a focal point of an optical system is adjusted, is disposed on the outside of a transparent bottom of each wells in a micro plate. A focus-shift-distance corresponding to a distance between the mark and a desired position to be observed is determined. The optical system focuses on the mark, and then, the focal point the optical system is shifted by the focus-shift-distance. This shift allows an object to be focused on accurately and rapidly even when unclear images are obtained.

Abstract: A microscope collision protection apparatus for a remote control microscope which protects the optical and associated components from damage in the event of an uncontrolled collision with a specimen, regardless of the specimen size or shape. In a preferred embodiment, the apparatus includes a counterbalanced slide for mounting the microscope's optical components. This slide replaces the rigid mounts on conventional upright microscopes with a precision ball bearing slide. As the specimen contacts an optical component, the contacting force will move the slide and the optical components mounted thereon. This movement will protect the optical and associated components from damage as the movement causes a limit switch to be actuated, thereby stopping all motors responsible for the collision.

Abstract: A magnifying scope and accessory holder having a main body having an upper end of reduced dimension for supporting a viewing aperture including an eye cup and window arrangement and a lower portion that includes an open-ended bore occupied by a focus tube in the form of a movable cylinder. The eye cup and window arrangement further includes a viewing lens which is of a suitable magnifying power. A mount is carried on the end of the focusing tube cylinder that detachably receives a variety of specimen holders.

Abstract: A method for aligning the optical beam path of a microscope, in particular of a confocal microscope having a light source (1), a microscope optical system, a detection stop (12), and a detection device (13), is configured, in the interest of simplified alignment with reduced service and maintenance costs, in such a way that the detection stop (12) is used as the optical reference. Also provided is a microscope assemblage, having a light source (1), a microscope optical system, a detection stop (12), and a detection device (13), in which the detection stop (12) is usable as the optical reference.

Abstract: A confocal microscope for observing the image of an object to be observed by scanning a spot light for illuminating the object through an objective lens, comprises an aperture stop for adjusting the numerical aperture of the objective lens; and a control unit for calculating a contrast of the image of the object corresponding to each focal position while varying the focal position of the objective lens along the direction of the optical axis so as to determine the height of the unevenness on the surface of the object from a change of the contrast, thereby setting the aperture stop to have the focal depth substantially equal to the height of the unevenness.

Abstract: A crash protection mechanism for a microscope objective includes a tapered, self-centering combination of sleeves interposed between the objective and its housing in an interferometric profiler. A three-lobed, tapered inner sleeve is affixed to the objective, while a matingly tapered outer sleeve is attached to the objective housing. A spring-loaded mechanism urges the objective outward toward the sample surface, so that it can move inward axially under crash conditions and then return to its original axial position. The mating tapered sleeves create an outward seated position that provides a high degree of repeatability when the objective is returned to its position after a crash.

Abstract: An operating microscope having an image projecting optical system (9) for introducing an image derived from an endoscopic optical system, which is provided separate from an operating-microscopic optical system, into an eyepiece optical system (18) of the operating microscope so that the operating-microscopic image and the endoscopic image can be simultaneously observed. The image projecting optical system (9) includes a collimating optical system (10), which collimates a beam of rays emergent from the image derived from the endoscopic optical system, and an imaging optical system (13), which forms an image on an image surface of the operating-microscopic optical system provided for observation via eyepiece using the beam of parallel rays emergent from the collimating optical system (10). The imaging optical system (13) is constructed to be movable at least in such a range that its entrance aperture can receive the beam of parallel rays.

Abstract: The present invention is an automatic focal point detection device. In a broad visual field and high resolution observation, when focusing is impossible in a splitting visual field obtained by splitting a specimen in a visual field in plural number, a stage is moved to an in-focus position stored in advance and focusing is executed. Besides the device is provided with an excitation light shutter for intercepting an excitation light with which a specimen is irradiated and when stray light corresponding to a difference detected by closing and opening the shutter in fluorescence observation is smaller than a specific value, specimen search is performed and focusing is executed at a level exceeding stray light, while the difference is equal to or larger than the specific value, focusing is executed with nothing more done.

Abstract: A stage assembly for holding a work-piece in a charged particle microscopy system includes a magnetic motor (e.g., brushless linear servo motor) for driving an X-platform riding on a base along the X axis, a non-magnetic linear motor (e.g., piezoelectric motor) for driving a Y-platform riding on the X-platform along the Y axis, and a non-magnetic rotary motor (e.g., piezoelectric motor) for rotating a rotary platform over the Y-platform, wherein the duty cycle of the magnetic motor is substantially greater than the duty cycle of the non-magnetic linear and rotary motors. This along with the particular arrangement of the motors and the platforms yields a compact, durable, and vacuum compatible stage which has minimal mechanical vibrations, minimal interference with the charged particle microscope, minimal particle generation, and high speed area coverage.

Abstract: A microscope including a support section for supporting a viewing section and an objective lens section and slidably supporting a stage section and a lighting section. The objective lens section includes a plurality of objective lenses having different magnifying factors and arranged linearly in a direction perpendicular to the support section and the objective lenses are contained in a downwardly directed housing while the stage section is contained in an upwardly directed housing so that a hermetically sealed housing can be formed of the downwardly directed housing and the upwardly directed housing by driving the stage section to slide.

Abstract: A light collecting optical system wherein the position where light is collected is scanned in the optical axis direction by using a wavefront converting element capable of changing power without using a mechanical device, and aberration occurring during the scanning is canceled by using the wavefront converting element to minimize the degradation of light collecting performance due to the scanning in the optical axis direction.

Abstract: A microscope having a mirror for deflecting light from an illumination light source in a direction of an objective lens and illuminating a specimen via a condenser lens disposed above the mirror includes a stage support which is mounted on the upper surface of a base portion to permanently hold a stage, on which a specimen is placed, with respect to the optical axis direction of the objective lens, a condenser body mounted on the upper surface of the base portion, a condenser lens holding member for holding the condenser body, an elevating mechanism for vertically moving the condenser lens holding member, and a focusing mechanism for moving the objective lens in the optical axis direction.

Abstract: An optical unit switching apparatus having a type-display section for displaying types of all optical units mounted on a movable member for switching and moving the optical units; and indicators arranged corresponding to respective mounting positions for the optical units for indicating a type of the optical unit inserted into an optical path. Since these indicators are located at different positions with respect to the centers of the corresponding mounting positions for the optical units, the indicators point at different positions in the type-display section when switching operations are performed. Accordingly, the type of the optical unit presently inserted into the optical path can be recognized by printing the names and the like of the respective optical units at the positions pointed at by the indicators corresponding to the respective optical units.

Abstract: An active optical image enhancer for a microscope, and a method of enhancing an image for a microscope, are provided. The image enhancer has a tube for attachment to a microscope. Photo-detector elements are disposed on an end of the tube remote from an end thereof that is attachable to the microscope. Lens elements are disposed in or on the tube between the photo-detector elements and the end of the tube that is attachable to the microscope. The optical path length of the tube is adjustable via an appropriate device.

Abstract: A near-field optical or magneto-optical data storage system uses an optical focusing device for focusing an incident optical beam to a small size focal spot. The optical focusing device includes an objective lens, an optically transparent base plate, and an optically transparent adapter. The adapter is secured to, and disposed intermediate the objective lens and the base plate, and includes an opening that faces the base plate. A fluid fills the adapter opening to form a fluid cell when the adapter is secured to the base plate. The fluid has an index of refraction that substantially matches the index of refraction of the base plate.

Abstract: Disclosed is an optical device with at least one lens and at least one swiveling observation tube, exhibiting the following characteristics: The observation tube comprises a base section fixedly connected to the optical device, and an eyepiece carrier which rolls along an arc of a circle so that swiveling can occur on the base section; a first rotatable deflecting mirror whose rotational axis orthogonally intersects the optical axis of an objective lens of the optical device and which is forcibly rotated by the movement of the eyepiece carrier on the base section; a second rotatable deflecting mirror is arranged in the eyepiece carrier and whose rotational axis orthogonally intersects the optical axis as deflected by the first deflecting mirror and which is forcibly rotated by the movement of the eyepiece carrier on the base section.

Abstract: An optical-path-difference automatic focusing apparatus for a microscope uses four automatic focusing control modes including an object search mode in which an object to be observed is searched for, a rough focus mode in which the object is brought to a roughly focused position with a lower accuracy of focusing, a front and back defocus sensing mode in which the degrees of front and back focusing of the object in at least a front and a back place with respect to the roughly focused position in the rough focus mode, and a fine focus mode in which the degree of focusing of the object with a higher accuracy of focusing is approximated linearly on the basis of the degrees of front and back focusing determined in the front and back defocus sensing mode and the object is brought to the focused position. Use of those modes realizes a highly reliable automatic focusing apparatus for a microscope capable of achieving a higher accuracy of focusing, regardless of the change of the optical condition.

Abstract: In a microscope such as for the examination of specimens in specimen vessels, a device for changing objectives is provided. The microscope includes at least a first objective. The device comprises an arrangement for providing an operating control so that the at least first objective can be raised and lowered vertically and is displaceable horizontally vertical to an optical axis of the microscope.

Abstract: For focusing an operation microscope within a defined focusing range, a main objective and parts of an illuminating device are arranged in a focusing module that is separate from the microscope body. The focusing module is movable along the optical axis in a defined manner by means of manual or motor drives, so that focusing on a desired object detail is possible. Desired fine focusing can thus take place, in addition to coarse focusing by spatial positioning of the operation microscope by means of a stand. The advantages are a compact design, prevention of reflections through the main objective, and widely varied possibilities for filling of additional accessories.

Abstract: An electrically-driven coarse and fine movement apparatus comprises a movable member, a driving device for driving the movable member, a first operation handle, a first rotary shaft fixed to the first operation handle, a second operation handle, disposed coaxially with the first operation handle, for rotating the first rotary shaft, a rotation restricting member for restricting a rotation of the second operation handle, which is accompanied with the rotation of the first operation handle, a rotation detector for detecting a rotational quantity and a rotational direction of the first rotary shaft, a discriminating device, linked to the second operation handle, for judging whether the second operation handle is operated or not to output a judging signal, and a controlling circuit for controlling the driving device so as to provide the movable member with a coarse movement in accordance with an operation of one operation handle of the first and second operation handles and to provide the movable member with a fi

Abstract: The invention relates to an operating microscope provided with at least one motor for a magnification adjustment (zoom 1), a distance or focus adjustment (focus 6), an X adjustment or canting (7) and a Y adjustment or tilt (8), in which the zoom adjustment serves as setting signal for the focus, the X and/or the Y adjustment both as to position as well as to speed (FIG. 1).

Abstract: A focusing apparatus for an optical apparatus comprises an operating member having a rotary shaft and an operating handle for rotating the rotary shaft, a support member provided with a bearing member and supporting a lens barrel having the focusing optical system of the optical apparatus and also rotatably supporting the rotary shaft of the operating member through the bearing member, a guide member engaged with the rotary shaft to move the support member in a predetermined direction with the rotation of the operating handle, and a rotational couple adjusting member disposed between the bearing member and the operating handle for adjusting the rotational couple of the operating handle.

Abstract: The preceding-profile of a specimen image upon inserting a preceding objective lens in the optical path to a specimen placed on a stage is detected. The succeeding-profile of the specimen image upon inserting a succeeding objective lens in the optical path is predicted on the basis of the preceding- and succeeding-optical parameters of the preceding and succeeding objective lenses inserted in the optical path, and the preceding-profile. The position of the stage with respect to the specimen is adjusted on the basis of the succeeding-profile obtained by this prediction.

Abstract: A confocal microscope is based on a low mass objective that is driven in one or more axis, with at least one of the axes being driven by a low mass device to provide mechanical scanning of the objective. The scanning mechanism has a low resonance so as to allow the scan length, rate, and range to be easily varied. Control of the objective's position can be either open or closed-loop servoed. The position of the objective can be determined in open-loop systems by calibration, by an internal reference signal coupled with a timing system, or via a means for an absolute or relative determination of the objective's position.

Abstract: A microscope capable of being fitted with a strap includes a microscope unit incorporating an optical system, a focusing unit supporting the microscope unit and movable to focus the optical system on an object to be observed, and a stage serving as a sustainer base for sustaining the microscope through the focusing unit. The focusing unit is provided with a strap fitting portion.

Abstract: A viewing arrangement includes an objective (5) having a variable intersection distance and an intersection-distance dependent oblique illumination (7) which is separate from the objective (5). The oblique illumination (7) includes two illuminating beam paths (9, 11) for completely illuminating contoured objects without shadows. The illuminating beam paths (9, 11) are inclined toward each other ahead of the object (13, 16) to be viewed. The mutual inclination of the two illuminating beam paths (9, 11) is dependent upon the particular intersection distance of the objective (5).

Abstract: An optical system which is telecentric to an image, having an objective optical system for forming a model image based on rays from the model magnified by a predetermined ratio to an actual object. An eyepiece lens is included for observing the model image formed through the objective optical system. The distance between the objective optical system and the eyepiece lens is varied so that a visual impression obtained by observing the model image through the eyepiece lens becomes substantially equal to a visual impression obtained by observing the actual object directly with the eyes.

Abstract: A microscope having a high effective numerical aperture (NA) is achieved in an apparatus in which a real, three-dimensional image is formed of an object placed in an aperture at the apex of one of two facing, axially-aligned concave mirrors. The three-dimensional image is acquired by a video camera positioned in a counterpart aperture at the apex of the other mirror and the acquired image is processed by computer. The processing corrects the acquired image using the point spread function of the mirror system which was previously obtained by positioning a point source of light throughout the object space and measuring the pixel values recorded by the camera's array of sensing element while the camera was positioned at different axial distances in the image space.

Abstract: A drive system for the conversion of a rotary motion into a linear motion contains a belt drive similar to a block and pulley system, and a system of a rack and pinion that is driven synchronously with the belt drive. The pinion and the rack are adjusted with respect to each other such that the teeth of the pinion engage with relatively large play in the rack. When driving under normal load, the drive takes place without loading of the rack and pinion system by the belt drive, so that the reversal backlash and the play of the rack and pinion system remain without effect on the displacement motion. When an overloading of the moving part and a corresponding stretching of the drive belt occur, the tooth flanks of the pinion and of the rack are supported against each other and in this manner prevent tearing or overloading of the drive belt.

Abstract: A gear unit (1) for focusing microscopes and having coarse adjustment, fine adjustment and extra-fine adjustment is described, in which, for the purpose of focusing, the object stage (5) is moved via a toothed gear (6). Coaxially arranged control knobs (7, 8) are provided on the microscope as manual control elements. The control knobs (7, 8) are connected via a drive shaft (9) and the gear unit (1) to a toothed rack (10) of the object stage. The control knob (7) for fine adjustment is provided on a rotation shaft (11) arranged so as to be capable of longitudinal displacement. Arranged on this rotation shaft (11) are at least two gear wheels (12, 13) of different diameter for fine adjustment and extra-fine adjustment. One of the gear wheels (12, 13) is connected to the gear unit (1) via the longitudinal displacement of the rotation axis (11).

Abstract: A stereotactic adapter on which a surgical therapeutic and/or diagnostic instrument is reproducibly mounted and attached to a surgical microscope that can be positioned in several spatial degrees of freedom. A position recognition system integrated in the surgical microscope permits safe positioning of the instrument used, given the geometric arrangement and the geometric dimensions of the surgical microscope, the adapter, and the instrument.

Abstract: An illuminating device for a stereo microscope having an objective with variable imaging focal intercept includes first coupling mechanism, which effects a coupling between the imaging focal intercept of the objective and the likewise adjustable focal intercept of the illuminating optical system, separate from the observation optics, in such a manner that the illuminating focal intercept is in agreement with the imaging focal intercept of the objective. Moreover, adjusting mechanism is provided for the defined adjustment of the diameter of the illuminated field. In particular, the illuminating device is suitable for a surgical microscope.

Abstract: A confocal microscope equipped with a light source, a rotary disk having holes, a highly sensitive image receiver or camera, an immersion lens, and a contact endpiece for contacting the skin and in which is engaged at least a lower part of the lens. The endpiece includes a central opening and abuts the skin about the central opening. The microscope allows for relative axial displacement of the contact endpiece relative to the lens.

Abstract: An automatic focus detection device for microscopes includes an optical system for forming an image of a sample; an image sensor for photoelectrically converting an optical image derived from the optical system; a device for storing image data such that an electric signal obtained from the image sensor is converted from analog to digital form and for processing the image data to compute contrast values; a device for comparing the contrast values; a device for moving an objective lens or a stage for the sample; and a device for storing the position of the objective lens or the stage.

Abstract: A coarse and fine adjustment focusing apparatus secured to a microscope body for moving a movable member includes a sun gear secured to a fine adjustment knob shaft, an internal gear unrotatably provided on the same axis as the fine adjustment knob shaft, a first planetary gear meshing with both the sun gear and the internal gear, a second planetary gear being equal in the number of teeth and module to the first planetary gear and disposed on the same shaft as the first planetary gear and meshing with the sun gear, a first resilient number for imparting rotational forces in opposite directions to the first planetary gear and the second planetary gear, a third planetary gear being equal in the number of teeth and module to the first planetary gear and disposed on the same shaft as the first planetary gear and meshing with the internal gear, a second resilient member for imparting rotational forces in opposite directions to the first planetary gear and the third planetary gear, and a power transmitting shaft to