Abstract: A lens-aperture control mechanism is provided for use in a lens unit to control the aperture of the lens unit. The lens-aperture control mechanism includes a plurality of blades, each being movable radially inward into the lens barrel and outward from the lens barrel; a rotatable ring coupled to the blades, capable of urging the blades to move radially inward into the lens barrel when being turned in a first direction and outward from the lens barrel when being turned in a second direction; and a power driver for driving the rotatable ring to turn in a specified direction by a specified angular displacement so as to move the blades to a specific radial position to define a specific aperture for the lens unit. The inner end of each of the blades is formed in a concave shape or a curved haft-cutaway portion. When combined, the inner ends of the blades can define a near-circular aperture for the lens unit.

Abstract: A zoom lens having three lens groups of positive, positive, and negative refractive power, in order from the object side. A diaphragm is positioned between the first and second lens groups. When zooming from the wide-angle end to the telephoto end, the diaphragm and the third lens group are moved as a unit while the spacing between the first lens group and the diaphragm increases, the spacing between the diaphragm and the second lens group increases, and the spacing between the second lens group and the third lens group decreases. Further, the zoom lens is constructed so as to satisfy the following condition-0.75<R.sub.G21 /f.sub.w <-0.23where R.sub.G21 is the radius of curvature of the surface of the second lens group that is nearest the object side, and f.sub.w is the focal length of the zoom lens at the wide-angle end.

Abstract: The present invention is directed toward a wide-angle lens. Because of a small quantity (two) of lens elements, the wide-angle lens facilitates size and weight reduction and permits low-cost manufacture. The lens is made from plastic, which permits further cost reduction. The lens is particularly useful when employed in CCD cameras.

Abstract: A collimator lens having five lens elements of negative, negative, positive, positive, and negative refractive power, in order from a collimated luminous flux side of the collimator lens, and designed to have a large back focus, to thereby prevent heat from the light source from causing aberrations in the collimator lens. The collimator lens includes a negative first lens element L.sub.1 of a meniscus shape with its concave surface on the collimated luminous flux side, a positive fourth lens element L.sub.4 with a convex surface on the collimated luminous flux side, and a negative fifth lens element L.sub.5 with a concave surface on the collimated luminous flux side. In addition, a diaphragm stop is arranged on the collimated luminous flux side of the first lens element, and certain conditions are satisfied to reduce aberrations and provide a large back focus.

Abstract: A lens system has the first and second lens components from the object side. The first lens component has a negative optical power. The second lens component has a positive optical power. The lens system fulfills the conditions: 0.0<PR.sub.L /Y'<0.5, 0.5<Pf/f<1.0. In the conditions, PR.sub.L represents a distance in a direction perpendicular to the optical axis between the optical axis and an incident position where a lower ray of a most off-axial rays enters said second lens component, Y' represents a largest image height, f represents a focal length of the entire lens system, and Pf represents a focal length of said second lens component.

Abstract: In a lens barrel, a flare diaphragm is disposed on an optical path of lenses or in the vicinity thereof such that the flare diaphragm can advance into and retreat from the optical path for cutting deleterious light corresponding to the lenses moving in the direction of the optical axis. This lens barrel can reliably cut deleterious light flux in a simple structure.

Abstract: Successively from an object side, a stop, a biconvex lens, a biconcave lens, a biconvex lens, and a meniscus lens having a convex surface directed onto the image side are disposed, while the image-side surfaces of the second and third lenses are set to have a predetermined range of power, thereby favorably correcting various kinds of aberration, such as distortion in particular, while reducing the size of the whole lens system. Disposed successively from the object side are a stop i, a first lens L.sub.1 made of a biconvex lens, a second lens L.sub.2 made of a biconcave lens, a third lens L.sub.3 made of a biconvex lens, and a fourth lens L.sub.4 made of a meniscus lens having a convex surface directed onto the image side. These lenses satisfy the following conditional expressions :0.4<R.sub.5/ f<2.00.4<.vertline.R.sub.7 .vertline./f<2.2whereinR.sub.5 is a radius of curvature of the surface of the second lens on the image side;R.sub.

Abstract: An optical unit provided between a plurality of light sources and a deflecting system in a multiple beam scanning optical system in which the appropriate intensity and appropriate intensity distribution of each beam on the scanned surface change are maintained regardless of foreseen changes in ambient temperature. The optical unit includes a condenser lens which condenses the beams emitted from the light sources and an aperture which regulates diameters of beams projected from the condenser lens. A connecting member which connects the condenser lens and the aperture at a distance corresponding to a focal length of the condenser lens.

Abstract: Disclosed is an apparatus for producing an original plate for optical discs, which is allowed to produce original plates for a plurality of kinds of optical discs satisfying various standards. The apparatus includes a laser light generator for generating laser light; a diaphragm mechanism for limiting laser light generated by the laser light generator; and an objective lens for refracting the laser light limited by the diaphragm mechanism in such a manner that the laser light is focussed on a photosensitive layer or a surface layer formed on the original plate; wherein a spot diameter of a beam of the laser light is changed by varying a diaphragm diameter of the diaphragm mechanism.

Abstract: An optical arrangement including a stop, and an optical element with a diffractive optical surface, wherein the diffractive optical surface is defined on a spherical surface of a curvature radius r, and wherein, where the distance from a point on the diffractive optical surface, which is on an optical axis, to a center of the stop as viewed from the diffractive optical surface is t, a relation 0.8.ltoreq.r/t.ltoreq.1.2 is satisfied.

Abstract: A reading lens system composed, in order from the object side, of a first positive biconvex lens component, a second positive meniscus lens component convex toward the image side and an aperture stop disposed on the image side of the second lens component. By setting a distance as measured from a first surface to an aperture stop of the reading lens system adequately, it is configured so as to have a short total length and allow little variation of a size of an image even when the image is defocused due to a variation of an object location.

Abstract: An optical scanner includes a housing having first and second obliquely adjoining windows. Disposed in the housing is a laser for projecting a laser beam against a rotatable spinner having a plurality of mirrored facets for sequentially reflecting the laser beam to effect a scan beam. A plurality of pattern mirrors are optically aligned with the spinner for reflecting the scan beam through the first and second windows to effect a plurality of individual scan lines arranged in first and second patterns corresponding with the first and second windows. The pattern mirrors include a triad set of mirrors optically aligned in series between the spinner and the first window for scanning the first scan pattern to a back edge of the first window for scanning at least the back side of a multisided item.

Abstract: A zoom lens system includes, in order from the object side to the image side, a first lens unit, having a negative refractive power, which moves along an optical axis during a zooming operation, a stop diaphragm which moves along the optical axis with the first lens unit at one body during the zooming operation, and a second lens unit having a positive refractive power.

Abstract: Distance L between best focus surface BF to reading opening 22 is in a range satisfying the condition: 2 mm.ltoreq..vertline.L.vertline..ltoreq.2a.multidot..omega./D, where "D" represents the size of a short side of an elongated hole of a diaphragm 34a, "a" represents a distance from an objective-side principal point of an imaging lens 34 to the best focus surface BF, ".omega." represents a minimum width of a module of bar code 8, "L" represents a distance measured from the best focus surface BF toward imaging lens 34, and .vertline.L.vertline. represents an absolute value of distance L. With this arrangement, adverse effect of stains, wounds and scratches of bar code 8 can be averaged or decentralized along the longitudinal direction of the bar of bar code 8 without deteriorating a reading accuracy in the lateral direction.

Abstract: An optical system for endoscopes which comprises a stop having a variable aperture and is configured so as to produce spherical aberration for preventing an image surface thereof from being shifted in a direction opposite to the object side by narrowing the aperture of the stop, whereby the optical system is free from insufficiency in brightness and degradation in resolution thereof on a side farther from the optical system within a depth of field thereof, and has another side of the depth of field brought close to the optical system.

Abstract: The present invention takes advantage of the efficiency of high-brightness red, infra-red, or other color LEDs arranged in a single row, the properties inherent to a focusing element such as a cylindrical lens, as well as the advantages of having a straight-edged diaphragm and a light-absorbing enclosure to produce an illumination source for machine-vision systems. The illumination source exhibits multi-directional properties on one side of an imaginary plane defined by the positions of the row of LEDs, the straight-edged diaphragm, and the focusing element, and minimize light cast on the other side of the plane. The present invention provides a compact light line generator which has no shadowing or secondary lines. The present invention also provides a method for measuring the height of a raised surface.

Abstract: A catadioptric reduction objective has a concave mirror 19', a beam splitter 150' and several lens groups (100', 200'; 300', 400'). The system diaphragm 40' is mounted between beam splitter surface 15' and image plane 36' and especially within the last lens group 400'. NA=0.7; for UV, DUV; image side or both sides telecentric; also achromatized.

Abstract: An optical pickup device for condensing the light from a light source on a signal recording surface by an objective lens and for detecting the return light from the signal recording surface by a light detection unit is disclosed. The optical pickup device is capable of recording and/or reproducing at least two different sorts of optical recording media. The light beam radiated from a light source is condensed by an objective lens. An aperture varying unit varies the size of an aperture of the objective lens depending upon the sorts of the optical recording media. The return light from the optical recording medium is detected by a light detection unit. The size of the aperture of the objective lens for condensing the light from the light source is varied depending upon the difference in substrate thickness of the different sorts of the optical recording media, thus assuring high-quality recording/reproduction for two or more different sorts of optical recording media.

Abstract: A controllable horizon diaphragm for planetaria with a housing and a cup-shaped diaphragm arranged in the beam path of a lens projecting fixed star transparencies into a dome. The controllable horizon diaphragm comprises a housing, a first and second bevel gear and a bearing ring. The housing, bevel gears and bearing rings are supported so as to be rotatable about an optical axis of the projecting lens. Separate driving devices drive each of the first and second bevel gears. The driving devices are coupled to a control unit. A third bevel gear is included which is rotatable about an axis extending vertically to the optical axis supported in the bearing ring. The diaphragm has a diaphragm body which is arranged at the third bevel gear in a stationary manner. The third bevel gear engages with the first and second bevel gears.

Abstract: An objective lens system for an endoscope comprises from the subject end to the image end a meniscus lens element of negative optical power having a concave image side surface, a plano-convex lens element of positive optical power having a convex subject side surface, an aperture element, a plano-convex lens element of positive optical power having a convex image side surface and a biconvex lens element of positive optical power.

Abstract: An optical transmission system permitting any desired machining to be done by radiating to an object to be irradiated a laser beam having an optimum intensity distribution in the direction of its optical axis or in a plane perpendicular to the optical axis, comprising a laser oscillator 1, an optical fiber 3 for propagating the laser beam emitted from the laser oscillator 1 by a predetermined distance, a condenser lens 2 for converging the laser beam from the laser oscillator 1 into the optical fiber 3, a first lens 6 for forming images with aberration from the laser beam emerging from the optical fiber 3, a mask 7 disposed in a position having a predetermined light intensity distribution out of the positions of the images formed by the first lens 6, and a second lens 4 for forming the image passing through the mask 7 onto an object 5 to be irradiated.

Abstract: An optical system composed of two lens elements and a postpositional aperture stop, which are arranged in such a manner as to facilitate mounting on a casing of a camera or lens-equipped photographic film package and to suppress spherical aberration to ensure high quality performance from center to peripheral regions despite asymmetric lens disposition. The optical system includes, from the object side, a first lens element L.sub.1, a second lens element L.sub.2, and a postpositional aperture stop D located behind the second lens element on the side of the image field. The first lens element is a positive meniscus having a convex surface disposed on the object side, and the second lens element is a biconvex lens. Alternatively, the first lens element is a biconvex lens, and the second lens element is a positive meniscus having a convex surface disposed on the side of the image field. The image surface of the optical system is curved in a convace shape on the object side.

Abstract: A photographic lens apparatus secures a sufficiently large back focus while sufficiently distancing the exit pupil position from the image-forming surface. From the object side along an optical axis L, a stop, a first lens, a second lens, a third lens having a meniscus form, and a fourth lens group, in which a lens having a negative refractive power and a lens having a positive refractive power are cemented together to yield a positive refractive power, are successively disposed. Refractive index n.sub.1 and abbe number .nu..sub.1 of the first lens, abbe number .nu..sub.2 of the second lens, radius of curvature r.sub.7 of the surface facing the object and radius of curvature r.sub.8 of the surface facing the image in the third lens, abbe number .nu..sub.4 of the lens having the negative refractive power and abbe number .nu..sub.5 of the lens having the positive refractive power in the fourth lens group, focal length f.sub.

Abstract: A diaphragm for an objective for imaging an image original to be scanned line-by-line onto an optical CCD sensor is provided in the optical part of a scanner device for automatic optical character recognition. The diaphragm has a diaphragm aperture expanded in a direction proceeding orthogonally relative to the CCD sensor. The shape of the diaphragm aperture deviates from a circular diaphragm aperture shape.

Abstract: The present invention relates to a projector using laser light, and more particularly to a ring-shaped laser spot capable of forming a projected image having a ring-shaped projected image formed from a diffraction fringe, by interposing a diaphragm between a collimator lens and a target. The collimator lens transmits laser light emitted from a laser light source to the target to form a first projected image on the target. The diaphragm shapes the laser light transmitted through the collimator lens to form a ring-shaped second projected image as a diffraction fringe on the target.

Abstract: An eyeguard for use on the eye-end of an optical instrument is provided having an instrument-end member adapted for connection to the optical instrument, an eye-end member adapted to interface with the periocular portion of the user's face, a hinge member disposed between the instrument-end and eye-end members having two flexible annular hinges, and a diaphragm comprising a plurality of segments attached to the interior of the hinge member between the annular hinges. The force of the user's eye pressing the eye-end member toward the instrument-end member deforms the annular hinges such that the normally closed diaphragm segments move to an open position, allowing light to pass through the eyeguard.

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 triplet lens using plastic lens elements is disclosed. The triplet lens includes, in order from the object side, a glass lens element that is positively meniscus having the convex surface on the object side, a plastic lens element formed of polycarbonate, polystyrene, or a copolymer of polystyrene and methacrylate which is biconcave in shape with a more pronounced concave surface on the image side, a plastic lens having a copolymer of polystyrene and methacrylate that is biconvex in shape, and a diaphragm. Lens characteristics are chosen to satisfy various conditions for optimum imaging.

Abstract: An external projection lens aperture, including a holder; an adjustable aperture mounted in the holder; and a self-centering clamping mechanism mounted in the holder for attaching the holder to an end of a projection lens barrel.

Abstract: A variable focus color corrected field lens for accepting rays having a divergence of from 0, wherein the rays are collimated, to a divergence of 10 milliradians full angle and directing the rays to the same point of an optical system. The present lens is corrected for wavelengths from the ultraviolet to the red spectrum of wavelengths for directing the wavelengths to the same point.

Abstract: The present invention provides a wide-angle lens for film-combined type cameras, comprising a first lens element having a negative refractive power and a second lens element having a positive refractive power which have more than one aspherical surface.

Abstract: A lens system 10 suitable for use in imaging on film F in panoramic cameras 100. The lens system 10 comprising an aperture stop ST, a front lens unit 20 located behind the aperture stop ST, the front lens unit 20 including a triplet; and a rear lens unit 30, preferably a meniscus lens element 32, located behind the front lens unit 20. The triplet consists of two negative power lens elements 22, 26 and a positive power lens element 24 located between the negative power lens elements 22, 26.

Abstract: Zoom lens systems for use with moderately large image formats, such as those found in instant photography cameras, are provided. The systems include three lens units arranged in a negative/positive/negative power sequence and have a fixed aperture stop associated with the unit nearest the image. The positive unit is used for zooming and either the first or the third negative unit is used for compensating and focusing. Alternatively, the negative unit nearest the image is used for compensating and the negative unit farthest from the image is used for focusing. The systems achieve a long back focal length, a short front vertex to image distance, and in their simplest embodiments can consist of just three lens elements.

Abstract: An optical device comprises a single lens of a meniscus-type lens whose index of refraction is distributed in a radial direction perpendicular to the optical axis thereof, and a diaphragm having an aperture and provided at the concave side of the meniscus-type lens, wherein the optical device satisfies following formulas,7.ltoreq.F.ltoreq.1620.degree..ltoreq.2.omega..ltoreq.90.degree. .

Abstract: A photographic lens system includes a positive meniscus lens whose the both lens surfaces are shaped in a aspherical surface respectively, the lens is arranged to satisfy the following inequality:0.02<t/L<0.05wherein the length of a diagonal line of an image forming plane on said image forming surface is 2L and the lens thickness on the optical axis is t.

Abstract: A magnetic element is provided on the outer periphery of a ring member which is operatively connected with diaphragm blades. This magnetic element is either shaped or constructed so that it exhibits a magnetic gradient (viz., produces non-uniform magnetic leakage flux properties). A Hall sensor is mounted stationarily with respect to the ring member so as to respond to the change in magnetic leakage flux and indicate the amount of rotation of the ring.

Abstract: A taking lens system for a camera includes a positive meniscus type of single component bi-aspherical lens and an aperture stop disposed facing a convex aspherical surface of the single component bi-aspherical meniscus lens. The single component bi-aspherical lens is designed and adapted such that a ratio of a radius of curvature of a reference concave spherical surface of the concave aspherical surface to a radius of curvature of a reference convex spherical surface of the convex aspherical surface is between 1.0 and 2.5.

Abstract: An objective lens for a free-space photonic switching system is disclosed. The objective lens is utilized to change a collimated array of beams into an array of spots which will focus on the array of spatial light modulating elements (S-SEEDs, for example). The requirements for the lens (low f-number, field of view, etc.), result in a lens which includes an external stop, positive doublet, a positive (e.g., plano-convex) lens and a negative (e.g., field flattener) lens, the latter pair of lenses being separated by a predetermined distance d.

Abstract: An optical apparatus for image scanning for reading image information recorded on an original by irradiating the original with reading light and reading the light transmitted through or the light reflected from the original using a photoelectric converter. In the optical apparatus for image scanning, a light source irradiates the original with the reading light. A slit is disposed between the light source and the original so as to control a range where the original is irradiated with the reading light. Condenser lenses are disposed between the slit and the original so as to concentrate the reading light transmitted through the slit on an image reading portion of the original. The photoelectric converter receives the reading light from the original and converts the received light into an electric signal. Another condenser lens is disposed between the original and the photoelectric converter so as to converge the reading light from the original on the photoelectric converter.

Abstract: An image reading lens that is constructed of, in succession from the object side, a stop, a meniscus-shaped positive first lens having its convex surface at the image plane side, and a negative second lens having its concave surface at the image plane side. Both the lens surfaces of the first lens and at least one lens surface of the second lens are constructed of an aspherical surface. The shape of the object side aspherical surface of the first lens is formed so as to be inside a reference spherical surface.

Abstract: A system and method for transmitting and monitoring laser light includes a laser for emission of a first beam with a given wavelength into a transmission path. A second beam is generated with a wavelength differing from the given wavelength. The second beam is coupled into the transmission path of the first beam and the first and second beams are superimposed in a propagation direction. The second beam is wavelength-selectively reflected in the transmission path as a reflected second beam. The reflected second beam is decoupled from the transmission path. A detector is provided for the reflected second beam. An interruptor is operatively connected to the detector for interrupting the first beam.

Abstract: Zoom projection lens systems are provided which have 1) an entrance pupil which remains at a substantially fixed position as zooming takes place, and 2) a operative aperture stop, distinct from the system's physical aperture stop, which moves through lens surfaces as zooming takes place. The fixed entrance pupil allows for efficient coupling to a light source throughout the magnification range of the system. Methods which can be used to design and produce zoom lens systems of this type and which employ a pseudo-aperture stop are also disclosed.

Abstract: A video camera in which an iris in an optical system is composed of a plurality of diaphragms, and at least two of the plurality of diaphragms are respectively provided with a light amount limiting filter such that the light amount limiting filters attached on the at least two diaphragms completely surround a transparent portion when the iris is half closed, to thereby provide satisfactory characteristics of the optical system when the iris is half closed.

Abstract: There is disclosed an simplified apparatus that enables optical scanners to achieve minimum field curvature and at the same time provide uniformly distributed light on an image sensor. A single element lens, preferably an aspherical lens made of a plastic material is combined with an aperture stop. The combination is capable of reducing lens aberrations and minimizing image field curvature for an object plane that contains indicia to be scanned or read. A suitably demagnified image of the indicia is focused onto an image sensor such as a CCD array. The spatial light distribution function in the image plane can be equalized by an attenuator, such as a neutral density filter or a slit, suitably configured to compensate for the reduced optical efficiency at large field angles. An aspherical lens containing a dye or a cold mirror can be used for limiting light transmission to a range of wavelengths.

Abstract: A lens system comprising, in order from the object side, a first lens component having a positive refractive power, a second lens component having a negative refractive power and a thrid lens component having a positive refractive power; the first lens component or the third lens component being a radial type graded refractive index lens component. The lens system is composed of the lens component in a number as small as three and has favorable optical performance.

Abstract: An exposure device in which a row of LED's is provided in the form of parallelograms having unequal sides, in which each of the corner points of one short side of a light-emitting surface is always in line, as considered in a direction perpendicular to the row, with one of the corner points of the other short side of an adjacent light-emitting element, and a printing device in which said exposure device is used.

Abstract: A device for microscopic sectioning and imaging of an object specimen illuminated with light comprises an objective lens, a diaphragm, and a pixel filter array. The objective lens focuses light from the object specimen to an image focal plane. The diaphragm blocks a portion of the focused light from the objective lens thereby creating a shadow. Each pixel filter in the pixel filter array has an axis and is arranged so as to cooperate with the shadow so that light from an object focal plane and parallel to the pixel filter axes reaches an output image plane.

Abstract: An apparatus for confining or limiting laser beams of medium and high power comprises a diaphragm 1, 1' which is mirrored and is arranged with respect to the laser beam 2 in such a manner that the beam portions (3, 3') reflected by the diaphragm are directed away from the laser beam axis A.

Abstract: There is provided a behind stop wide angle lens system which comprises a positive lens L.sub.1 formed by joining a negative meniscus lens L.sub.11 whose convex surface faces an object and a positive meniscus lens L.sub.12 whose convex surface similarly faces the object, a biconcave negative lens L.sub.2, a biconvex positive lens L.sub.3 and an aperture stop S, disposed in this order from the side of the object. The behind stop wide angle camera achieves a wider angle of view and has an excellent imaging performance in spite of a simple structure and a compact size thereof.

Abstract: A compact-size, light-weight, low-cost zoom lens system with high optical quality is achieved by using a ray restrictor placed at the most object side of the zoom lens system. In one type, the ray resistor shifts toward the object at a speed different from that of the most object side lens of the zoom lens system as the zoom lens system is zoomed toward the longest focal length, which effectively blocks harmful rays causing coma flare in the peripheral area. In another type, the aperture diameter of the ray restrictor varies according to a zooming operation. The ray restrictor of any type is especially effective when used in a zoom lens system composed of two lens groups. By introducing one or more aspherical surfaces satisfying a certain condition (or conditions) in the zoom lens system, various aberrations are further favorably corrected.