Abstract: A reimager comprises precisely two positive lenses wherein the chromatic longitudinal aberration lies within the depth of focus and the thermal image position variation likewise lies within the depth of focus over a temperature range of more than .+-.30.degree. (in the embodiment from -40.degree. C. to +70.degree. C.). Aspheric and diffractive surfaces are utilized and, if required, are joined on respective lens surfaces (31, 51, 53, 71, 73).

Abstract: An achrathermalized reimager includes a front objective defining an optical axis and a relay optic arranged on the optical axis downstream of the front objective. The front objective is both achromatic and athermalized and includes precisely one negative lens made of a material selected from the group consisting of ZnSe and ZnS and one positive lens made of chalcogenide glass.

Abstract: A method and apparatus to correct and eliminate optical anomalies and geometrical distortions in an intensified imaging system, specifically a night vision system. An image is received from the original objective lens assembly of an unintensified imaging system which, presumably, has been designed to produce images sized in accordance with the image sensor size of its host camera or camcorder. The format matching lens assembly receives the image from the original objective lens system and magnifies it so that it is output onto the entire circular active area of a mechanically inserted image intensifier. Having received an image across its entire circular active area, the image intensifier is able to amplify or intensify the image using the received light without creating any optical distortions. Once intensified without distortion, the image must be still further modified to fit its original format size.

Abstract: A low cost optical viewing device includes an objective lens section, a relay lens section and an eye piece section. The relay lens section is devoid of glass rods and includes a minimal number of lenses each preferably fabricated from plastic material. The illumination system includes a plurality of optical fibers also preferably fabricated from plastic material.

Abstract: An image detection system (10) uses an optical configuration for both image forming and calibration phases of operation. A field lens (20) has an inner portion (36) of a conventional prescription to allow for collection of scene based energy for an opto-electronic approximation of the infrared detail within the afocal field of view by a focal plane array (32). The field lens (20) also has an outer portion (38) that collects far field energy from a scene area (A.sub.I) through a converging point (P.sub.I). The energy collected from the scene area (A.sub.I) is indicative of the average energy level within the scene. The electrical equivalent values of all energy received from the unique area (A.sub.I) is stored in a multidimensional range used for subsequent gain and offset calibration coefficient calculations.

Abstract: A real image mode finder optical system has an objective system constructed with an objective lens including a single lens with positive refracting power and a first reflecting member; an intermediate image plane; and an ocular system constructed with a second reflecting member and an eyepiece including a single lens with positive refracting power. This finder optical system satisfies the following conditions:-4<r1/r2<-1, r2<0where r.sub.1 and r.sub.2 are radii of curvature of the surfaces of the objective lens which are located on the object and image sides, respectively.

Abstract: In a non-flexible endoscope consisting of an insertion section and an eyepiece section which are separable from each other, an optical system configured so as to correct chromatic aberration produced by an observation optical system disposed in the insertion section with an eyepiece optical system disposed in the eyepiece section. The optical system according to the present invention selects a simple composition for the observation optical system so that it is manufacturable at a low cost and disposable, and is configured so as to have favorable optical performance as a whole by correcting chromatic aberration produced by the observation optical system with the eyepiece optical system.

Abstract: The present invention allows one to take an intermediate image formed by a microscope objective lens system and reform a clear image of it, at relatively low magnification, on a film surface. The present invention provides for a lens system which comprises, in order, from the observed object end, a first lens group having a convex surface facing toward the objective lens system end, and having positive refractive power, a second lens group, positioned to the rear of the intermediate image, and having negative refractive power, and a third lens group having positive refractive power. The lenses in the system are set to follow predetermined parameters.

Abstract: A head-up display system comprising an optical combiner 5 for positioning in front of a pilot's head, in-line with the pilot's normal line of sight and in a plane substantially transverse to said line of sight. Sensor means, comprising a pair of optical sensors 9,10, is arranged to detect motion of the pilot's head towards the combiner 5 and to cause a trigger signal to be generated, prior to impact between the pilot's head and the combiner, if the velocity of said motion exceeds a threshold velocity. Retraction means 7 are coupled to the sensor means for receiving therefrom said trigger signal and are arranged, in response to receipt of said trigger signal, to retract the combiner 5 out of the trajectory of the pilot's head prior to impact between the head and the combiner.

Abstract: Optical systems for endoscopes, borescopes, dental scopes, and the like which are characterized by having three groups of lenses of positive optical power and an external entrance pupil. Typically, all three groups of lenses are displaced from the pupil and focal planes. As a consequence, the displaced groups take part in the image transfer as well as in the pupil transfer. The optical power requirements can thus be shifted from one group to another, distributing as well as reducing the overall power requirement. Moreover, the aberration correction can also be shared between these groups. The first group, which conventionally has the highest optical power, and consequently a large amount of aberrations to be corrected, can in this way transfer some of the optical aberration correction to the other groups. The sharing of the optical functions and aberration correction results in a fully integrated optical system.

Abstract: The light-weight high-magnification clinical viewer includes a three-element objective lens and a two-element eyepiece lens. Use of multiple lenses allows for a more compact package. The doublet eyepiece lens serves to reduce chromatic aberration at high magnification. The triplet objective serves to avoid vignetting while providing a wide field of view and reduced chromatic aberration. Image quality is further enhanced, while keeping the weight of the viewer down, through the use in the objective of light-weight high index glass.

Abstract: An display apparatus has an image displaying device for modulating light by a spatial light modulation element and displaying an image, a relay optical system for forming the image on an imaging plane at a location differing from the image displaying device, an eyepiece optical system for directing the light from the imaging plane to an observer's pupil, and light beam controlling device provided in a portion of the relay optical system for controlling the amount of transmission of a light beam from the image displaying device correspondingly to the inclination of the contrast distribution of the light beam.

Abstract: A double sided telecentic measurement objective for contactless length measurement in two-dimensional and three-dimensional space. The objective has an image-side optical system consisting of three elements equivalent to those of an object-side optical system but in the reverse order, including a cemented positively refracting lens element turned toward the object of image respectively, a collecting lens spaced by an air gap from the cemented lens, and a dispersive meniscus spaced by an air gap from the collecting lens. The widths of the air gaps between the collecting lenses and the meniscus are substantially greater than the widths of air gaps between the cemented lens elements and the collecting lenses.

Abstract: A stereomicroscope comprising an objective lens system and eyepiece lens systems, the objective lens system comprising at least two lens units, permitting a working distance thereof by varying at least one airspace and having a concave surface at a location farthest from an object to be observed so as to minimize lowering of the magnification of the stereomicroscope and stereoscopic impressions of images observed through the stereomicroscope.

Abstract: A monolithic relay lens system for an endoscope is provided and includes a plurality of alternating individual polymeric lens elements bonded together with optical cement lenses of predetermined optical properties. In particular, multiple biconcave lenses of a first polymeric material are bonded to and alternated with multiple biconcave lenses of a second polymeric material by biconvex optical cement material lenses, in order to provide a monolithic and cylindrical achromatic optical structure. The polymeric lens elements of the system can be mass produced using injection molding. Low temperature polymeric material combinations, such as polystyrene and acrylic, are most easily injection molded and may, together with the optical cement, be used to manufacture disposable and very inexpensive relay lens systems. On the other hand, where a temperature resistant, autoclavable endoscope is preferred, high temperature polymeric lens combinations, such as polycarbonate and TPX can be used.

Abstract: A stereoscopic-vision endoscope having an objective optical system consisting of a front optical system having a single optical axis including a field conversion optical system, and a rear optical system including optical systems that have a plurality of optical axes. A light beam is received from the front optical system so as to form images on the optical axes, and thus form a plurality of images. The front and rear optical systems can be turned relative to each other. Thus, a magnitude of parallax permitting a sufficient sense of three-dimensionality can be provided, and the postures of images can be corrected responsively to a change in direction of view resulting from the rotation of an insertional part.

Abstract: A relay lens system to be incorporated in an endoscopic optical assembly is provided. The relay lens system includes at least one relay lens module for relaying an image between successive image planes. The relay lens module consists of two identical optical assemblies arranged in bilateral symmetrical relation relative to a median plane disposed between the two assemblies. Each optical assembly includes a glass plano cylinder and first and second curved lens components attached to each end of the plano cylinder. The lenses forming the lens components are fabricated from different optical materials including polymeric materials to correct aberrations within the system. The physical and geometrical characteristics of the components are selected to effectively transfer a bright image to the viewer.

Abstract: A method for producing a lens system is provided in which an exact field curvature (EFC) value is determined for at least one principal ray, the EFC value being given by:EFC=-.SIGMA.(n'-n)c/nn'the summation being taken over the surfaces of the system, and for each of the surfaces, n is the index of refraction on the object side of the surface, n' is the index of refraction on the image side of the surface, and c is the curvature of the surface at the intersection of the surface with the principal ray, c being positive if the center of curvature is on the image side of the surface.

Abstract: A line light source illuminator for a film scanner of the type having a linear image sensor, a film gate through which an area of film to be scanned can be positioned, and an aperture at the film gate for defining the area of film to be scanned. The illuminator includes a light source which produces a light beam; an optical condenser between the lamp and the film gate to condense and shape the beam; and optics adapted to diffuse and direct the light beam so as to produce a uniform line of controlled diffuse illumination at the film gate. A spherical relay lens between the lamp and the optical condenser has a focal length nominally equal to a distance between the relay lens and the optical condenser to constrain the beam within the entrance pupil of the optical condenser. A spectral filter is between the lamp and the film gated to remove unwanted wavelengths of radiation from the light beam.

Abstract: An image stabilizer has, in succession from the object side, an objective lens group having at least positive refractive power, variable angle prism having its vertical angle variable, and optical prism, and which satisfies the following condition:-20<.nu..sub.VAP -.nu..sub.RP <40,when .nu..sub.VAP is the Abbe's number of the variable angle prism, and .nu..sub.RP is the mean value of the Abbe's number of the optical prism.

Abstract: An objective has a first group of lenses with a first optical axis and a second group of lenses with a second optical axis. The optical axes are offset from and parallel to one another. A pair of Porroprisms is disposed between the first lens group and the second lens group and serves to rotate images. The Porroprisms cause a shift in optical axis, and the first and second optical axes are spaced from each other by a distance corresponding to this shift. The arrangement is such that light travelling along the optical axis of one lens group can enter the Porroprisms for reflection to the optical axis of the other lens group. The first lens group has negative refractive power while the second lens group has positive refractive power. A rhomboidal prism is located on the side of the second lens group remote from the Porroprisms and functions to cause a shift in optical axis equal but opposite to the shift caused by the Porroprisms.

Abstract: A monolithically integrated optical disk pickup head is comprised of three-dimensional collimating focusing lenses, a beam splitter and 45-degree reflectors that define an optical axis in free-space using surface micromachining technology to fabricate hinged vertical optical structures.

Abstract: The light-weight clinical viewer includes a two-element objective lens and a single-element eyepiece lens. Use of multiple lenses allows for a more compact package. The doublet objective serves to reduce vignetting while providing a wide field of view and reduced chromatic aberration. Image quality is further enhanced, while keeping the weight of the viewer down, through the use in the objective of light-weight high index glass. Moreover, the invention permits the use of a single mounting barrel assembly for different eyepieces to reduce manufacturing costs.

Abstract: A telecentric relay lens system is provided with field lenses in the vicinity of an object and an image, respectively, at both sides of a centrally arranged lens member. In order to produce distortion the field lenses include cemented surfaces, the cemented surface of one of the field lenses being a collective surface, the cemented surface of the other of the field lenses, being oppositely arranged relative to the central lens member, being a diverging surface.

Abstract: An optical apparatus that enables an object at a first location to be viewed from a second remote location. The optical apparatus includes at least one objective lens assembly that views the object at the first location. The objective lens assembly focuses the viewed image onto the input plane of an image conduit. The fiber optic conduit propagates the image to the second remote location, wherein the image is projected from the image conduit onto the back surface of a substantially transparent planar member. The back surface of the planar member is not highly polished. As a result, the image projected onto the back surface does not pass directly through the planar member. The reflections caused by the unpolished nature of the surface allow the image to be viewed on the back surface of the planar member through the body of the planar member.

Abstract: A nonimaging radiant energy device may include a hyperbolically shaped reflective element with a radiant energy inlet and a radiant energy outlet. A convex lens is provided at the radiant energy inlet and a concave lens is provided at the radiant energy outlet. Due to the provision of the lenses and the shape of the walls of the reflective element, the radiant energy incident at the radiant energy inlet within a predetermined angle of acceptance is emitted from the radiant energy outlet exclusively within an acute exit angle. In another embodiment, the radiant energy device may include two interconnected hyperbolically shaped reflective elements with a respective convex lens being provided at each aperture of the device.

Abstract: A collimator lens system for collimating diverging light bundle emitted from a light source into a parallel light bundle includes first to third lens elements arranged in this order from the side of the parallel light bundle. The first lens to third elements are a positive double-convex lens, a negative lens concave to the side of the parallel light bundle and a positive lens convex to the side of the parallel light bundle, respectively. The following formulae (1) to (5) are satisfied0.8<f.sub.1 /f.sub.3 <2.0 (1)1.5<{r.sub.2 (n.sub.2 -1)}/{r.sub.3 (n.sub.1 -1)}<2.7 (2)0.8<r.sub.5 /{f(n.sub.3 -1)}<1.4 (3)0.8<-r.sub.1 /r.sub.2 <2.4 (4)0.5<-f.sub.2 /f<6.0 (5)wherein f represents the overall focal length of the collimator lens system, f.sub.i represents the focal length of i-th lens element, i standing for 1, 2 or 3, r.sub.i represents the radius of curvature of i-th refracting surface as numbered from the side of the parallel light bundle, i standing for 1, 2, 3, 4, 5 or 6 and n.

Abstract: A telescope includes a master telescope whose aberration has been independently corrected and which has an objective lens and an ocular lens. A rear conversion lens is provided on the image side of the objective lens of the master telescope and is made of a single lens having a concave surface that faces an object side. The rear conversion lens meets the requirements defined by the following relationships: f.sub.o '/f.sub.o >1 and 0.5<(dx.sub.2 /dh.sub.2)/(dx.sub.1 /dh.sub.1)<1.3, wherein "f.sub.o " represents the focal length of the objective lens of the master telescope; "f.sub.o '" represents the resultant focal length of the objective lens of the master telescope and the rear conversion lens; "dx.sub.1 /dh.sub.1 " represents an inclination of an incident surface of the rear conversion lens at an incident point thereof, upon which light is incident at a height h.sub.1 ; "dx.sub.2 /dh.sub.

Abstract: A finder optical system including an objective system, an image erecting system for erecting an object image formed by the objective system, and an eyepiece system for observing the object image. These systems are constructed of low-hygroscopic organic materials. Thus, the finder optical system can prevent transient variations of optical properties caused by hygroscopicity.

Abstract: An endoscope comprising, in order from the object side, an objective optical system and image relaying optical systems disposed in a number of n, and using, in a (n-1)th or nth image relaying optical system, an optical system for producing positive distortion so as to cancel negative distortion produced by the objective optical system, thereby correcting distortion favorably in the endoscope as a whole.

Abstract: A relay lens system for an endoscope is provided and includes three axially aligned cylindrical lens pairs, each lens pair having two substantially rod-like lenses. Each rod-like lens includes a convexo-concave polymeric aspheric lens and a concavo-convex polymeric aspheric lens which are symmetrically placed and affixed about a glass rod with flat ends by means of plano-convex optical cement lens elements. The optical cement lens elements form lens-like elements which contribute to both the color and geometric aberration correction of the lens system. When inserted as a component of an endoscope or laparoscope, the distal end of the relay lens system is axially aligned with an objective lens and the proximal end is axially aligned with a viewing eyepiece. The image formed at the distal end of the endoscope by the objective lens is transmitted by the relay lens system, which inverts once and refocuses twice before forming a final upright image in front of the eyepiece for viewing or recording.

Abstract: A compact, simple real image finder includes an objective, a field lens, erecting optics and an eyepiece. The field lens is separated from an internal image sufficiently that it contributes substantially to the magnification of the finder.

Abstract: A field curvature corrector is provided which has a positive power and a positive exact field curvature (EFC) value for at least one principal ray, where the EFC value is given by:EFC=-.SIGMA.(n'-n)c/nn'the summation being taken over the surfaces of the corrector, and for each of the surfaces, n is the index of refraction on the object side of the surface, n' is the index of refraction on the image side of the surface, and c is the curvature of the surface at the intersection of the surface with the principal ray, c being positive if the center of curvature is on the image side of the surface. By means of the corrector, the field curvature of a positive lens system can be corrected without the use of negative lens elements.

Abstract: A nonimaging radiant energy device may include a hyperbolically shaped reflective element with a radiant energy inlet and a radiant energy outlet. A convex lens is provided at the radiant energy inlet and a concave lens is provided at the radiant energy outlet. Due to the provision of the lenses and the shape of the walls of the reflective element, the radiant energy incident at the radiant energy inlet within a predetermined angle of acceptance is emitted from the radiant energy outlet exclusively within an acute exit angle. In another embodiment, the radiant energy device may include two interconnected hyperbolically shaped reflective elements with a respective convex lens being provided at each aperture of the device.

Abstract: An objective lens for microscopes has an optical unit removably disposed at the front end of the objective lens. The optical unit includes at least two kinds of optical elements having different optical properties. Thus, the objective lens for microscopes can always maintain good imaging performance in the case where either a glass or plastic vessel is used.

Abstract: The light-weight high-magnification clinical viewer includes a three-element objective lens and a two-element eyepiece lens. Use of multiple lenses allows for a more compact package. The doublet eyepiece lens serves to reduce chromatic aberration at high magnification. The triplet objective serves to avoid vignetting while providing a wide field of view and reduced chromatic aberration. Image quality is further enhanced, while keeping the weight of the viewer down, through the use in the objective of light-weight high index glass.

Abstract: An optical subassembly for transferring light between an optoelectronic converter and an optical fiber where the housing and the lens are of plastic in which the housing is made to dimensions within the precision of molded plastic and the lens imparts focusing properties that compensate for the limitations of the plastic technology. Alignment in the X-Y plane only is employed. The lens has a first surface focused on the optoelectronic converter which substantially collimates the light through the lens and a second surface that introduces deliberate longitudinal spherical aberration that compensates for component position. Attachment or fixing of the optoelectronic converter to the housing is accomplished by RF heating a TO can to quickly cure an epoxylayer.

Abstract: A multiple lens element macrolens system operative as a single lens has a high light transmission value and a wide field of view of an object to be viewed. The macrolens system provides a long object working distance and an extended back focal distance to an image plane. An object group of lens elements is spaced by a substantial axial gap from an image group of lens elements. The gap and the working and back focal distances facilitate inclusion of various auxiliary components into an optical instrument which incorporates the macrolens system.

Abstract: An optical instrument for indirectly observing an object includes a first lens system for producing a first image of the object, and an adjustable second lens system for producing a second image of the object. The second lens system is continuously adjustable between a first position wherein the second image has maximum magnification and/or a minimum area of view, and a second position wherein the second image is of a minimum magnification and/or a maximum area of view. In one aspect of the invention, the second lens system is a zoom lens system having two substantially fixed conjugate planes. In another aspect of the invention, the instrument defines a folded optical path through the lens systems which includes a generally U-shaped portion so as, in use, to reduce the separation of the observer and the observed object.

Abstract: Aperture stops are positioned in the optical train of a partially overlapped binocular display in a such a manner that overlapping portions the binocular boundaries of the left and right fields of view are substantially out of focus, and therefore do not appear as well defined, distracting contours in the visual field. The present invention is particularly well suited for use in virtual reality systems employing head mounted displays.

Abstract: An illumination optical system for endoscopes which comprises a lens component having at least one aspherical surface in a shape F(h) satisfying the condition mentioned below, and satisfies relationship of h=f.cndot..theta. or h=f.cndot.sin.theta.. This illumination optical system is capable of providing favorable luminance distributions on all planar surfaces, spherical surfaces and tubular surfaces.

Abstract: A light-weight clinical viewer includes a two-element objective lens and a single-element eyepiece lens. Use of multiple lenses allows for a more compact package. The doublet objective serves to reduce vignetting while providing a wide field of view and reduced chromatic aberration. Image quality is further enhanced, while keeping the weight of the viewer down, through the use in the objective of light-weight high index glass. Moreover, the invention permits the use of a single mounting barrel assembly for different eyepieces to reduce manufacturing costs.

Abstract: The present invention relates to a relay lens system, wherein all image aberrations are corrected. This permits modular use with no stand-alone lenses or lenses with great focal distance. The relay lens system comprises at least two subsystems, wherein at least one positive lens and at least one negative lens are placed in at least one subsystem near the intermediate image, and the refractive index N(+) of at least one positive lens and the refractive index N(-) of at least one negative lens and the total focal distance F(FLD) of the lenses of the subsystem near the intermediate image correspond to the following relations:N(+)>N(-)and F(FLD)>0.

Abstract: A collapsible terrestrial telescope having a lens system which includes an objective lens and a terrestrial eyepiece, wherein the eyepiece includes an erecting lens group, and an eyepiece lens. The objective lens and the erecting lens group each include an aspheric surface. The objective lens may be one of an optically interchangeable doublet including a positive element having the aspheric surface and a negative element, or a singlet having the aspheric surface and a diffractive surface.

Abstract: A lens system disposed between the emitting area of a laser diode and a focal plane for focusing the output beam of the laser diode on the focal plane is disclosed, in which system, as regards a direction parallel to the lengthwise direction of the emitting area of the laser diode, the emitting area and the focal plane are conjugate, and a telescopic optical system is formed of the lens system to form a telescopic image indicative of the exit pupil of the lens system at an infinite distance and to make small the convergent angle of the laser beam incident on the focal plane.

Abstract: A real image type of finder optical system, provided separately from a photographing optical system. A real image is formed by an objective optical system and is observed through an ocular optical system. The objective optical system includes at least one lens that is made of synthetic resin and has at least one lens surface coated with an anti-reflection material.

Abstract: A low cost optical viewing device for viewing a remote location comprises three sections of an objective lens, relay lens and eye piece wherein all three sections of the present invention are free of conventional and relatively expensive glass rods. The preclusion of the glass rods leads to an overall lower cost (e.g., disposable) optical viewing device (e.g, borescope and endoscope). In addition, the optical viewing device of the present invention achieves lower cost by the use of a combination of molded plastic lenses and glass lenses. In accordance with still another important feature of this invention, the method of illuminating the remote location to be viewed is accomplished by using low cost plastic optical fibers which are twisted so that the field of illumination is increased and may be tailored to match (or be no less than) the size of the field of view of the optical viewing device. Still another significant feature of the present invention is its low weight.

Abstract: An afocal optical system is formed by a paraboroid mirror and an optical element having a stereographic projection characteristics which is defined by the following equation:hi'=2.multidot.f.multidot.tan (.theta.i/2)where hi' is a height of a light beam, leaving the optical element, taken from the optical axis or a heigh of an image taken from the optical axis, f is a focal length of the optical element and .theta.i is an angle of incidence with respect to the optical element. The focal point of the optical element coincide with that of the first paraboroid mirror. Thus, a compact afocal optical system which satisfies hi'=m.multidot.hi is manufactured at low costs.

Abstract: An endoscope including a disposable probe and a non-disposable focusing ocular. The probe comprises negative and positive gradient index of refraction objective elements and a transfer module.

Abstract: The present invention provides an image processing apparatus capable of forming a sharp image of a detection mark formed in a plane. The image processing apparatus comprises a camera unit (1) comprising a lens system (12) and a photodetecting device (13) inclined at a predetermined angle to the optical axis (L') of the lens system. The camera unit (1) is disposed with the optical axis (L') of the lens system (12) inclined at a predetermined angle to a perpendicular line (L) to the plane including the detection mark so that the difference in length between respective sections of light paths between diametrically opposite portions of the detection mark and the lens system is canceled by the difference in length between respective sections of the same light paths between the lens system and the photodetecting device.