Abstract: An optical film has a transparent film and an adhesive layer provided on one surface of the transparent film. The adhesive layer has a refractive index different by 0.12 or less from that of a layer of the one surface of the transparent film. The transparent film has an average in-plane retardation of not larger than 30 nm. A repetitive prismatic structure is provided on the other surface of the transparent film, the repetitive prismatic structure having optical path changing slopes aligned in a substantially constant direction at an inclination angle in a range from 35 to 48 degrees with respect to a plane of the transparent film.

Abstract: A real image type zoom finder that, albeit being reduced in size and thickness, can gain high enough zoom ratios and an imaging system equipped with such a real image type zoom finder. The real image type zoom finder comprises an objective optical system, an image-erection optical system and an eyepiece optical system. The objective optical system comprises a negative first lens group, a positive second lens group, a negative third lens group and a positive fourth lens group. Upon zooming, the first lens group and the fourth lens group remain fixed, the second lens group moves toward the object side at the telephoto, not the wide-angle end, and the third lens group moves toward the image side at the telephoto, not the wide-angle end. The first lens group consists of one single lens of double-concave shape, and that single lens satisfies condition regarding a shape factor.

Abstract: The invention concerns a stereomicroscope (1) for magnifying an object (T), having at least one zoom (22) through which, in the operating state, an object beam (K1) emitted from the object (T) is directed, the stereomicroscope (1) comprising a first deflection device (P4), arranged physically behind (after) the zoom (22) in the light path, for deflecting the light beam directed through the zoom (22) into a direction (A3) that deviates by less than 45° from the direction opposite to the object beam (K1). The light beam (A1) directed through the zoom (22) is advantageously deflected substantially into the direction opposite to the object beam (K1).

Abstract: A variable power finder is proposed, which comprises: an objective system; an inverting system; and an ocular system, in order from object side. The third lens group of the objective system is constituted by one lens prism having at least one reflection surface, and following expressions are satisfied: f3/fw?2.5??(1) ?1.0>R32+R31)/(R32?R31)>1.0??(2) L1/fw2?0.45 1/mm??(3) L2/fw2?0.03 1/mm??(4) where f3 is a focal distance of in millimeters (mm) third lens group, fw is a focal distance in mm at wide angle end of objective system, R31 is a curvature radius of object side lens surface of lens prism, R32 is a curvature radius of image side lens surface of lens prism, L1 is an air equivalent distance in mm from middle imaging surface to object side lens surface of lens prism, and L2 is a distance in mm from middle imaging surface to image side lens surface of lens prism.

Abstract: A terrestrial telescope with digital camera has an imaging optical system having a group of objective lenses and an imaging element disposed at a position at which an optical image is formed by the group of objective lenses. An observation optical system is provided for observing the optical image transmitted by the group of objective lenses. An optical element is inserted into the optical axis so as to be retractable from the optical axis during imaging. The optical element has a transmission surface having a single-eccentric toroidal configuration with different curvatures in vertical and horizontal planes of the optical element for correcting the position on the imaging element at which the optical image is formed so that the position on the imaging element at which the optical image is formed remains substantially unchanged regardless of whether the optical element is inserted into or retracted from the optical axis of the group of objective lenses.

Abstract: A compact spotting scope includes a housing with an outer surface having a grasping region sized and shaped to fit in the palm of a user's hand so that the spotting scope can be held at eye level with one hand in an ergonomic arm and wrist position for steady support. An optical element positioned within the housing is adjusted by manually rotating a side-mounted adjustment knob that extends laterally from the outer surface of the housing opposite the grasping region. The side-mounted position of the adjustment knob allows the arm and wrist of the focusing hand to be maintained in an ergonomic position during manipulation of the adjustment knob, thereby further facilitating steady support. An internal support member of the spotting scope includes a frame portion and a generally tubular portion, which are preferably formed together of unitary one-piece construction for aligning optical elements of the spotting scope.

Abstract: A real image type variable magnification finder comprises, an object optical system having positive refracting power which forms an objective image as a middle image, a view frame arranged near a position of the middle image, and an eyepiece optical system having positive refracting power which forms a pupil for observing the middle image, wherein an erect image optical surface for making the erect image by bending optical path is formed on the way of these optical paths. The object optical system comprises, in order from an object side, a negative lens element which is a single lens, a positive lens element which is a single lens, wherein both lens elements are moved by changing a distance between the negative lens element and the positive lens element when magnification is varied.

Abstract: Microscope, particularly a stereomicroscope, for simultaneous observation of an object by a first and a second observer, comprising a main objective (2) having an optical axis (2a); an optical viewing path; a plurality of deflector elements (5, 6, 7) for deflecting the optical viewing path into a first plane I extending at an angle to the optical axis of the main objective and subsequently into a second plane II substantially parallel to and above the first plane I; an uncoupling device (7) in the optical viewing path for uncoupling an optical viewing path of the second observer from an optical viewing path of the first observer; and a deflector element (20) for deflecting the optical viewing path of the second observer into a third plane III which extends substantially parallel to the first and second planes I, II, wherein the second plane II is located between the first plane I and the third plane III.

Abstract: A variable power finder is proposed, which comprises: an objective system; an inverting system; and an ocular system, in order from object side. The third lens group of the objective system is constituted by one lens prism having at least one reflection surface, and following expressions are satisfied: f3/fw?2.5??(1) ?1.0<(R32+R31)/(R32?R31)<1.0??(2) L1/fw2?0.45 1/mm??(3) L2/fw2?0.03 1/mm??(4) where f3 is a focal distance in millimeters (mm) of third lens group, fw is a focal in mm distance at wide angle end of objective system, R31 is a curvature radius of object side lens surface of lens prism, R32 is a curvature radius of image side lens surface of lens prism, L1 is an air equivalent distance in mm from middle imaging surface to object side lens surface of lens prism, and L2 is a distance in mm from middle imaging surface to image side lens surface of lens prism.

Abstract: A variable power finder is proposed, which comprises: an objective system; an inverting system; and an ocular system, in order from object side. The third lens group of the objective system is constituted by one lens prism having at least one reflection surface, and following expressions are satisfied: f3/fw?2.5??(1) ?1.0<(R32+R31)/(R32?R31)<1.0??(2) L1/fw2?0.45 1/mm??(3) L2/fw2?0.03 1/mm??(4) where f3 is a focal distance of in millimeters (mm) third lens group, fw is a focal distance in mm at wide angle end of objective system, R31 is a curvature radius of object side lens surface of lens prism, R32 is a curvature radius of image side lens surface of lens prism, L1 is an air equivalent distance in mm from middle imaging surface to object side lens surface of lens prism, and L2 is a distance in mm from middle imaging surface to image side lens surface of lens prism.

Abstract: Stereomicroscope having an objective (6) and a zoom system (8) downstream of the objective, the optical axis (6a) of the objective forming an angle with an axis (9) of the zoom system (8), and a plurality of deflector elements (10, 12a to 12e) by means of which at least one observation beam emerging from the objective (6) can be guided into the zoom system (8), and at least one observation beam emerging from the zoom system (8) can be guided at least on to another axis (15) extending substantially parallel to the axis (9) of the zoom system (8), while on the axis (9) of the zoom system (8) and/or on the minimum of one axis (15) extending substantially parallel thereto, there is provided at least one optical element (19) for extending the beam path of the at least one observation beam along the optical axis (9) of the zoom system (8) and/or the at least one axis (15) parallel thereto.

Abstract: A vision assisting apparatus includes a casing for forming an inversely U-shaped optical path, a light entry, provided at one end of the optical path, through which light enters, a light exit, provided at another end of the optical path, through which light exits in an opposite direction to the light entry, an optical system for processing an image entered via the light entry by using the optical pass and outputting a processed image via the light exit, and attaching structure for attaching the casing to a wearer so that the light exit is positioned close to an eye of the wearer. By forming the inversely U-shaped optical path with the casing, it is possible to provide a sufficiently long optical path in a compact form.

Abstract: Microscope, particularly a stereomicroscope, for simultaneous observation by a first and a second observer, comprising a main objective (2) defining an optical axis (2a) and an optical beam path (17) following a direction of the optical axis (2a); a magnification system (12, 13) mounted after the main objective (2); a beam splitter device (5) mounted after the main objective (2) for deflecting a first partial optical beam path (17a) into a first plane (I) of the microscope, and for transmitting a second partial optical beam path (17b) in the direction of the optical axis (2a); a plurality of deflector elements (6a, 6b) for deflecting the first partial optical beam path (17a) out of the first plane (I) and into a second plane (II) of the microscope extending substantially parallel to the first plane (I); and a further deflector element (6c) for deflecting the second partial optical beam path (17b) into a third plane (III) of the microscope extending substantially parallel to the first and second planes (I, II)

Abstract: An optical device uses in a plane image input device. The optical device comprises a body including an incident end and an emergent end. After a light beam enters the body via the incident end, undergoes a total reflection, and emerges from the emergent end. Thus, the size of the plane image input device can be minimized and the optical energy attenuation can be reduced during the transmission process.

Abstract: A compact magnification-varying viewfinder optical system includes an objective lens unit for forming a primary image, the objective lens unit having at least one curved reflection surface arranged to reflect a light flux and a lens surface, and an eyepiece lens unit for observing the primary image, wherein an optical power is imparted to the curved reflection surface.

Abstract: A real-image finder optical system includes a positive objective optical system, an erecting optical system, and a positive eyepiece optical system, thereby an object image, which is formed by the objective optical system, and is upside down and reversed from left to right, is reinverted by the erecting optical system to the proper orientation. The erecting optical system includes a plurality of reflection surfaces, at least one of which is provided along an optical path on the object side with respect to the position where the object image is formed, and at least another of which is provided along an optical path on the eyepiece side with respect to the position where the object image is formed. The eyepiece optical system includes a positive lens element having a transverse magnification of more than 1.0 provided between the object image (finder image) and the reflection surface provided on the eyepiece side with respect to the position where the object image is formed.

Abstract: An image-erecting viewing optical system includes a first prism having an incident surface and at least two reflection surfaces, a front lens group of an objective optical system, a second prism having an incident surface and at least two reflection surfaces, a rear lens group of the objective optical system, a field stop, and an eyepiece optical system, in this order from the object. One reflection surface of the first or second prism includes a roof-mirror surface. The following conditions are satisfied: sin(????)>1/n??(1) 6°<?<16°??(2) wherein ? designates an angle between the incident surface and the first reflection surface of the first prism; ? designates a real field-of-view ? (half amount); ?? designates an angle between a light ray of a real field-of-view ? (half amount) and the optical axis within the first prism; and n designates the refractive index of the first prism.

Abstract: A fusion monitor system for vehicles which includes a sideview mirror unit having an object lens and an eye lens at both sides of a housing which is disposed backwardly from inside and outside of the vehicle and a movable reflecting mirror between two lenses to form an afocal optical system, a movable reflecting mirror driving unit for rotating the movable reflecting mirror, a terminal holder for accepting a mobile phone, a display panel for outputting the same information as that of a display window of the mobile phone through the mirror unit. According, air resistance can be reduced, information outputted on the display window of the mobile phone can be enlarged for easy viewing and reading, and it allows hands free for user's convenience.

Abstract: A microscope tube comprises a housing (1) having a lower housing part (3) and an upper housing part (2), input optics (9) mounted on the lower housing part (3), which are provided for coupling to an infinite optical path of a microscope, a tube lens (12) mounted in the upper housing part (2), which is arranged on a common optical axis (OA1) with the input optics (9) and combines ray pencils supplied by the input optics (9) in an intermediate image, so that a finite optical path is formed between the tube lens (12) and the intermediate image, and a prism unit (13) mounted in the upper housing part (2) and arranged following the tube lens (12), said prism unit (13) deflecting the further optical path (OA2) by a solid angle of between 65° and 75° and being arranged in the finite optical path such that the intermediate image is viewable without further intermediate imaging by binocular optics (4) mountable on the upper housing part (2), said upper housing part (2) and said lower housing part (3) being mut

Abstract: An observation optical system of the present invention comprises an image erect optical system and an eyepiece optical system for observing an object image.

Abstract: A compact spotting scope includes a housing with an outer surface having a grasping region sized and shaped to fit in the palm of a user's hand so that the spotting scope can be held at eye level with one hand in an ergonomic arm and wrist position for steady support. An optical element positioned within the housing is adjusted by manually rotating a side-mounted adjustment knob that extends laterally from the outer surface of the housing opposite the grasping region. The side-mounted position of the adjustment knob allows the arm and wrist of the focusing hand to be maintained in an ergonomic position during manipulation of the adjustment knob, thereby further facilitating steady support. An internal support member of the spotting scope includes a frame portion and a generally tubular portion, which are preferably formed together of unitary one-piece construction for aligning optical elements of the spotting scope.

Abstract: The invention concerns an optical instrument having at least one binocular viewing port, in which in the two channels of at least one binocular beam path there are provided beam splitters that make it possible to reflect a portion of the beam path out onto an imaging device or the like, and to reflect into the respective channel, toward the viewing port, data or images that have been made available.

Abstract: A compact Keplerian optical system includes a telescope having an image-rotator (Pechan roof prism pair), and an eyepiece and objective lens operative to form an intermediate image plane within the image-rotator, thereby decreasing the overall length. The objective lens optionally forms part of a replaceable cap, and plurality of replaceable caps may be provided, each with a different focal length to adjust for working distance. In the preferred embodiments, the eyepiece includes a singlet and a doublet lens to minimize eyestrain, and the objective lens includes a doublet and singlet field lens operative to increase depth of field and field of view. A practical implementation includes a pair of the telescopes, one for each eye of a user. Such a configuration may take the form of loupes mounted relative to eyeglass frames for surgical, medical or dental viewing applications.

Abstract: An optical instrument for observation includes, in order from the object side, an objective lens system having positive refractive power, an erecting optical system, and an ocular lens system having positive refractive power. When an anti-vibration mechanism is used to maintain the erecting prism at an orientation in space that is stabilized so as to prevent image degradation due to vibrations of the optical instrument for observation, the erecting prism is constructed to satisfy specified conditions so that ghost light is not generated and so that the optical instrument for observation may be compact.

Abstract: A viewing optical system includes an objective optical system and an eyepiece optical system. The objective optical system includes a positive first meniscus lens element having the convex surface facing toward the object, a positive second meniscus lens element having the convex surface facing toward the object, a negative third lens unit constituted by two negative lens elements, and a positive fourth lens element. The fourth lens constitutes an image-blur correcting optical system movable in a direction perpendicular to the optical axis. The viewing optical system satisfies the following conditions: 0.5<|tan 1°/(&phgr;1-4−&phgr;1-3)|<5 (mm) . . . (1) 0.5<SF4<1.0 . . .

Abstract: A viewfinder optical system includes an objective lens unit, an image inverting unit for converting an object image formed via the objective lens unit into a non-inverted erecting image, and an eyepiece lens unit for observing the non-inverted erecting image, wherein the image inverting unit comprises a first transparent body and a second transparent body which are disposed with an interval put therebetween, the second transparent body having only a function of transmitting a ray of light, and wherein the interval between the first transparent body and the second transparent body is not uniform.

Abstract: The invention relates to apparatus and methods for increasing visual acuity through the use of a bioptic telescope which is at least partially embedded in a spectacle lens. In one embodiment, the telescope includes a vision lens having a vision axis and a first surface for placement substantially in front of an eye of a user. The telescope further includes a plurality of optical elements defining an optical path for viewing an object in front of the first surface. At least one of the plurality of optical elements is positioned such that at least a portion of the optical path is located within the vision lens in a plane substantially orthogonal to the vision axis.

Abstract: An optical sight for a combat vehicle, intended to be mounted in a weapon turret of the vehicle in order to make possible sight lines at elevations between roughly −10° and 90° of a weapon barrel mounted pivotably about a horizontal axis in the weapon turret. The sight comprises a lower standard sight unit, which deflects vertical incident light by 90° to an eyepiece, and a top mirror, located above the standard sight unit and pivotable in synchronism with elevating movements of the barrel, likewise about a horizontal axis. Positioned above the standard sight unit is a deflection prism which has an upper surface which faces the top mirror, is inclined at roughly 45° to the vertical and is designed to reflect incident light at an angle of roughly 45° to the surface and less, but to transmit light which is incident at roughly 90° to the surface.

Abstract: A high-performance real-image finder optical system reduced in size, particularly in thickness, includes a positive objective optical system, an image-inverting optical system for erecting an intermediate image formed by the objective optical system, and a positive ocular optical system. The objective optical system has at least two movable units moving when zooming is performed. A prism is placed on the object side of the intermediate image. At least one reflecting surface of the prism has a rotationally asymmetric surface configuration. At least one reflecting surface of the image-inverting optical system is formed from a roof surface. The finder optical system satisfies the following condition: 1.0<d/(fW·tan &thgr;W·Z)<2.

Abstract: A viewing apparatus in which an object image formed by an objective lens system is viewed through an eyepiece system includes a beam splitter which is located closer to an object than a focal plane of the objective lens system in a light path of the objective lens system, a negative lens provided in an optical path of light split by the beam splitter, and a photographing optical system attachment/detachment portion provided on a light emission side of the negative lens.

Abstract: A binoculars for capturing images includes two optical systems and a image-capturing device installed in one optical system. The optical system having the image-capturing device includes a beam-splitting element, and the beam-splitting element divides a beam into two beams, wherein one beam is received by eye and another beam is received by the image-capturing device simultaneously. Consequently, the image-capturing device takes photos through the optical system of the binoculars.

Abstract: An optical system comprises, in succession from the object side, a first optical element of negative optical power, a second optical element of positive optical power, and a third optical element of negative optical power, at least one of the first to third optical elements being a refracting optical element having a reflecting curved surface.

Abstract: An auxiliary binocular device for astronomical telescope, comprising a center tube, a left lens unit, a right lens unit and a beam splitter and image-inverting device, the objective lens of the binocular device being joined to the eyepiece of astronomical telescope, so the telescope becomes binocular. The beam splitter and image-inverting device is installed inside the center tube, the right lens unit and the left lens unit, comprising a beam splitter prism, three reflected mirrors and two lens sets, having beam splitting and image-inverting functions.

Abstract: A microscope has a light source that emits an illuminating light beam for illumination of a specimen, an apparatus for determining the light power level of the illuminating light beam and a beam splitter separating measuring light out of the illuminating light beam. The microscope permits determination of the light power level of the illuminating light beam with an apparatus for simultaneous color-selective detection of the measuring light.

Abstract: The invention relates to an image reversion system (500) which enables an image reversion and beam transposition of a plurality of observation beam paths (503a, 503b, 504a and 504b) to be carried out simultaneously. The system includes at least one Porro prism system and is designed in such a way that it can be arranged in a convergent beam path. The inventive system is suitable as an image reversion system in an ancillary module for operational microscopes used in ophthalmoscopy due to the low overall height thereof.

Abstract: In an illumination incoupling system for an optical viewing device, illumination incoupling is provided simultaneously into main observer beam paths and assistant observer beam paths using two semitransparent and two fully reflective deflection elements arranged crosswise and symmetrically with respect to the optical axis of the main objective. Homogeneous illumination of the specimen field may thereby be achieved for both the main observer and the assistant observer.

Abstract: A surface light source device includes a light guide plate. A light beam generated from a point light source is irradiated from a corner portion formed at a side surface of the light guide plate. The irradiated light beam is emitted from an upper surface on which prisms are formed. The prisms extend in a circular arc form so as to connect two side surfaces forming the corner portion.

Abstract: An astronomical viewing instrument with a helmet-mounted optical assembly comprising a pair of binocular tubes, each with an objective lens, attached to a base plate. The base plate is connected via a first hinge to the helmet worn by the viewer. The binocular tubes are also attached to a first pair of apertures in a mirror housing which has a second pair of apertures with threaded tees, at an angle relative to the first pair, for connection to a pair of prism housings ending in eyepieces for the viewer. The prism housings provide for a parallel offset such that their individual rotation around the mirror housing tees changes the distance between the eyepieces to match the distance between the pupils of the viewer. The first hinge serves to accommodate different head sizes of viewers and allows to adjust the weight, via the cushioned eye-pieces, on the eyes of a viewer.

Abstract: The invention relates to an optical device comprising a stereomicroscope having a lens (4, 13), and a laser (5) which emits a laser beam (8) for machining a workpiece (9). The inventive device is characterised in that a tiltable mirror (10) is provided, by means of which the laser beam (8) can be guided through the lens (4, 13) over the workpiece (9).

Abstract: The object of the present invention is to provide a real image viewfinder optical system with high optical performance and compactness, whose dimension of a whole optical system including an image inverter optical system is small in the thickness direction, and whose dimension to an object side of an eyepiece lens system is small in the thickness direction. A real image viewfinder optical system comprises, in order from an object side, an objective lens system having a positive refractive power as a whole, an eyepiece lens system for observing a real image formed by the objective lens system and having a positive refractive power, and an image inverter optical system for erecting the image to be observed and arranged to an exit pupil side of a lens located to the most object side of the objective lens system and also to the object side of a lens located to the most exit pupil side of the eyepiece lens system. Conditional expressions are satisfied.

Abstract: An optical instrument for observation includes, in order from the object side, an objective lens system having positive refractive power, an erecting optical system, and an ocular lens system having positive refractive power. When an anti-vibration mechanism is used to maintain the erecting prism at an orientation in space that is stabilized so as to prevent image degradation due to vibrations of the optical instrument for observation, the erecting prism is constructed to satisfy specified conditions so that ghost light is not generated and so that the optical instrument for observation may be compact.

Abstract: Binoculars having a prism assembly between the objective and ocular, wherein the prism assembly is secured on a prism holding device by means of a permanently elastic sealing compound.

Abstract: The observation instrument for a stereoscopic operation microscope, with input connections (1) for the two beam paths (2, 7, 19) of the operation microscope, with instruments (8) for connecting observation tubes for the main observer, with display-screen units (11) and projection instruments (13) for projecting the images from the display-screen units (11) into the observation beam paths (2, 7, 19), with instruments for connecting video cameras and with instruments (10) for connecting tubes for a co-observer, is distinguished in that the following are arranged in each of the two beam paths behind the input connections (1), as viewed in the direction of the beam paths (2, 7, 19): a first beam splitter (3) for deviating a part of the light of the observation beam path into a video camera, behind this a switchable shutter (4) for attenuating and/or blocking the light of the observation beam path, and behind this an optical element (21, 23) with a second beam splitter (22), which splits the light of the observati

Abstract: Improved binoculars are provided for viewing objects at a distance and for selectively recording a digital image of the objects. The binoculars include first and second monoculars each with an optical lightpath constructed to deliver an image of the object to one eye of the observer. Included within one of the monoculars is a beamsplitter designed to allow a portion of the light in the first optical lightpath to pass to the eye of the observer and to reflect a second portion of the light. The reflected portion of the light is directed to a digital image sensor and recording device. The other monocular includes compensating optics, such as a second beamsplitter, to alter the image to correct for the refraction and decrease in light intensity caused by the beamsplitter in the first light path. The second monocular does not include an image sensor and does not include an image recording device.

Abstract: The invention relates to an optical sight for a combat vehicle, intended to be mounted in a weapon turret (26) of the vehicle in order to make possible sight lines at elevations between roughly −10° and 90° of a weapon barrel mounted pivotably about a horizontal axis in the weapon turret. The sight comprises a lower standard sight unit (12), which deflects vertical incident light by 90° to an eyepiece (16), and a top mirror (18), located above the standard sight unit (12) and pivotable in synchronism with elevating movements of the barrel, likewise about a horizontal axis. Positioned above the standard sight unit (12) is a deflection prism (20) which has an upper surface (22) which faces the top mirror, is inclined at roughly 45° to the vertical and is designed to reflect incident light at an angle of roughly 45° to the surface and less, but to transmit light which is incident at roughly 90° to the surface (22).

Abstract: The invention relates to a tube for an optical instrument, such as a microscope, having several rotary joints (19, 20, 21) connected serially one behind the other. Each of the rotary joints (19, 20, 21) includes a brake (32, 33, 38) via which the rotary joints are secured against an unintended rotation. The brakes of the rotary joints (19, 20, 21), which are connected serially one behind the other, are simultaneously releasable by actuation of the single operator lever (39). For this purpose, a system of pins (42) and tilt levers (43) is mounted in the tube via which the actuation of the operator element (39) is transmitted to the brakes (32, 33, 38) connected serially one behind the other.

Abstract: An image-erecting viewing optical system includes a first prism having an incident surface and at least two reflection surfaces, a front lens group of an objective optical system, a second prism having an incident surface and at least two reflection surfaces, a-rear lens group of the objective optical system, a field stop, and an eyepiece optical system, in this order from the object. One reflection surface of the first or second prism includes a roof-mirror surface.

Abstract: An endoscope includes an optical train or image-to-video conversion device, defining a longitudinal axis, for receiving an image for transmission to a viewing device. A first prism having a reflective surface at 45° to the longitudinal axis and laterally offset from is mounted for rotation about an axis that is perpendicular to and intersecting the longitudinal axis and the axis intersecting the center of the reflective surface. A second prism with a reflective surface at 45° to and intersecting the longitudinal axis is also provided. The field of view is illuminated by light transmitted to a third prism with a reflective surface mounted symmetrically about the longitudinal axis with respect to the first reflector and rotatable synchronously with the first reflector. In this way, the direction of view and of illumination can an be varied synchronously over a range of about 120°.

Abstract: A telescope includes an erecting system having first, second, third and fourth reflecting surfaces from an object side, the first and second reflecting surfaces and the third and fourth reflecting surfaces facing each other at right angle, respectively. An objective lens located between the first and fourth reflecting surfaces has a positive refractive power to converge object light that is reflected by at least the first reflecting surface for forming an image. An eyepiece located between the fourth reflecting surface and an eye point, has a positive refractive power to magnify the image formed by the objective lens. The first reflecting surface is formed on a retractable mirror that can swing between a working position such that the first and second reflecting surfaces are perpendicular, and a retracted position such that a free end of the retractable mirror moves close to the second reflecting surface.

Abstract: Binoculars which are flat in the direction of view include two powerful Keplerian telescopes placed in two flat containers covering each eye and held by an eyeglass frame resting on the nose and ears; the binoculars can be easily converted into magnifying reading eyeglasses by touching a knob on the temple side of each telescope.