Asymmetric (e.g., Prismatic Or Eccentric, Etc.) Patents (Class 359/720)
  • Patent number: 6215596
    Abstract: An optical element integrally has an optically acting surface, which is a rotationally asymmetric, aspherical surface, and a monitor surface for evaluation of whether the optical element is defective or not. The monitor surface is provided in a portion effecting no optical action, except for the optically acting surface.
    Type: Grant
    Filed: September 13, 1999
    Date of Patent: April 10, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keisuke Araki, Tsunefumi Tanaka, Hiroaki Hoshi
  • Patent number: 6208468
    Abstract: A distortion-free and compact image-forming optical system with a minimal number of optical components which provides a wide image area and which is favorably corrected for ray aberrations and arranged in a compact structure by folding an optical path. A pentagonal prism member (5) has a first surface (1), a second surface (2), a third surface (3), and a fourth surface (4). The first surface (1) and the fourth surface (4) are refracting surfaces. The second surface (2) and the third surface (3) are reflecting surfaces. The first surface (1) is formed from a spherical surface. The second surface (2), the third surface (3) and the fourth surface (4) are formed from three-dimensional surfaces. Light rays from an object plane O provided on the back side of a cover glass (6) pass through the cover glass (6) and enter the prism member (5) through the first surface (1). The incident light rays are reflected successively by the second surface (2) and the third surface (3).
    Type: Grant
    Filed: January 5, 1999
    Date of Patent: March 27, 2001
    Assignee: Olympus Optical Co., Ltd.
    Inventors: Takayoshi Togino, Tsutomu Uzawa
  • Patent number: 6166866
    Abstract: A reflecting-type optical system according to the invention includes an optical element composed of a transparent body having an entrance surface, an exit surface and at least three curved reflecting surfaces of internal reflection. A light beam coming from an object and entering at the entrance surface is reflected from at least one of the reflecting surfaces to form a primary image within the optical element and is, then, made to exit from the exit surface through the remaining reflecting surfaces to form an object image on a predetermined plane, In the optical system, 70% or more of the length of a reference axis in the optical element lies in one plane.
    Type: Grant
    Filed: February 26, 1996
    Date of Patent: December 26, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kenichi Kimura, Tsunefumi Tanaka, Toshiya Kurihashi, Shigeo Ogura, Keisuke Araki, Makoto Sekita, Nobuhiro Takeda, Yoshihiro Uchino, Toshikazu Yanai, Norihiro Nanba, Hiroshi Saruwatari, Takeshi Akiyama
  • Patent number: 6157500
    Abstract: A flow cell 2, a composite lens 15, and first to third detectors 16 to 18 are arranged in this sequence in the light pathway of light emitted from a laser light source 1. The composite lens 15 is configured by a convex lens 15a, and lens elements 15b and 15c. These lenses have different focal lengths. When the posture of the composite lens is correct, light impinging on the convex lens forms an image on the first detector. Therefore, the positioning of the composite lens is enabled. When particles in the flow cell are irradiated with laser light, forward scatter is produced. Forward small angle scatter having a small scattering angle impinges on the first lens element 15b to be collected thereby, and is then received by the second detector 17. Forward large angle scatter having a large scattering angle impinges on the second lens element 15c in the outermost periphery to be collected thereby, and is then received by the third detector 18 which is remotest from the composite lens.
    Type: Grant
    Filed: December 9, 1999
    Date of Patent: December 5, 2000
    Assignee: Nihon Kohden Corporation
    Inventors: Masao Yamazaki, Yutaka Nagai, Katsuhiro Tsuchiya, Yoshiyuki Takahara
  • Patent number: 6124989
    Abstract: A high-performance image-forming optical system made compact and thin by folding an optical path using reflecting surfaces arranged to minimize the number of reflections. The image-forming optical system has only one prism member. The prism member has a first surface through which a light beam enters the prism member, a second surface reflecting the incident light beam in the prism member, a third surface reflecting the reflected light beam in the prism member, and a fourth surface through which the light beam exits from the prism member. At least one of the second and third surfaces has a curved surface configuration that gives a power to a light beam. The curved surface configuration has a rotationally asymmetric surface configuration that corrects aberrations due to decentration. A pupil is provided between the first and fourth surfaces, for example, on the second surface.
    Type: Grant
    Filed: June 14, 1999
    Date of Patent: September 26, 2000
    Assignee: Olympus Optical Co., Ltd.
    Inventors: Hisashi Oode, Takayoshi Togino
  • Patent number: 6104540
    Abstract: An optical system capable of correcting aberrations due to three-dimensional decentration by using a rotationally asymmetric surface having no plane of symmetry. The optical system includes, from the ray bundle entrance side, a first surface (3) serving as both a first transmitting surface and a second reflecting surface, a second surface (4) as a first reflecting surface, and a third surface (5) as a second transmitting surface. The space between these surfaces is filled with a medium having a refractive index larger than 1. The first surface (3) is a three-dimensional surface having no plane of symmetry.
    Type: Grant
    Filed: January 8, 1999
    Date of Patent: August 15, 2000
    Assignee: Olympus Optical Co., Ltd.
    Inventors: Kazuhito Hayakawa, Takayoshi Togino
  • Patent number: 6097421
    Abstract: In a scanning optical system in which image-surface curvature in the traverse direction is corrected properly without degrading imaging performance in the scanning direction and in which the transverse magnification is approximately uniform irrespective of the deflection angle, the influence of form errors in the imaging lens upon the image is substantially suppressed so as not to degrade the quality of the image. The scanning optical system is provided with a aspherical lens having a refractive power only in the traverse direction and having a TSL shape whose curvature radius increases as the distance in the scanning direction from the center of the lens (the position in which the curvature radius in the traverse direction is smallest) increases. The aspherical lens is disposed in such a way that the line of symmetry that passes through its center is parallel to and at a distance from the optical axis of a first lens unit on the upstream side of a scanning path in the scanning direction.
    Type: Grant
    Filed: November 4, 1996
    Date of Patent: August 1, 2000
    Assignee: Minolta Co., Ltd.
    Inventors: Kenji Takeshita, Nobuo Kanai
  • Patent number: 6094315
    Abstract: A high-performance and low-cost image-forming optical system made compact and thin by folding an optical path using reflecting surfaces having power. The optical system has a plurality of reflecting surfaces having power. Among the reflecting surfaces, a reflecting surface (12) of negative power is placed closest to the object side, and a reflecting surface (22) of positive power is placed closer to the image side than the reflecting surface (12). At least one reflecting surface (13) is provided between the reflecting surface (12) and the reflecting surface (22). An axial principal ray (1) incident on the reflecting surface (13) satisfies the condition of 45.degree.<.vertline..theta..vertline., where .theta. is the angle formed between the axial principal ray and a line normal to the reflecting surface (13) in the decentration direction at a point where the axial principal ray (1) intersects the reflecting surface (13).
    Type: Grant
    Filed: May 18, 1999
    Date of Patent: July 25, 2000
    Assignee: Olympus Optical Co., Ltd.
    Inventor: Norihiko Aoki
  • Patent number: 6078441
    Abstract: An array of graduated prisms disposed in a circle for rotating an incident image, the prisms are disposed with their end faces at the periphery of the circle and their apices at the center. The end faces are all oriented in the same direction either clockwise or counterclockwise, depending on the direction of rotation.
    Type: Grant
    Filed: May 14, 1999
    Date of Patent: June 20, 2000
    Inventor: Michael Lahood
  • Patent number: 6069724
    Abstract: An optical scanning apparatus includes an optical scanning lens composed of a single lens which is arranged and adapted to correct for placement errors of optical elements. The shapes of both surfaces of the optical scanning lens are non-arc in a deflective surface and at least one surface thereof has a special toric surface. The scanning lens is meniscus having a concave shape in a sub-scanning direction and is biconvex in a main scanning direction.
    Type: Grant
    Filed: February 10, 1998
    Date of Patent: May 30, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshinori Hayashi, Seizo Suzuki, Koji Masuda
  • Patent number: 6018423
    Abstract: The present invention is an optical apparatus, e.g. an image display apparatus, which enables observation of a clear image at a wide field angle with substantially no reduction in the brightness of the observation image, and which is extremely small in size and light in weight and hence unlikely to cause the observer to be fatigued. The optical apparatus has an image display device (6), and an ocular optical system (7) for leading an image of the image display device (6) to an observer's eyeball (1). The ocular optical system (7) includes, in order from the image side, a third surface (5) which forms an entrance surface, a first surface (3) which forms both a reflecting surface and an exit surface, and a second surface (4) which forms a reflecting surface. The first to third surfaces (3 to 5) are integrally formed with a medium put therebetween which has a refractive index larger than 1.
    Type: Grant
    Filed: June 11, 1998
    Date of Patent: January 25, 2000
    Assignee: Olympus Optical Co., Ltd.
    Inventor: Koichi Takahashi
  • Patent number: 5999147
    Abstract: A head-coupled display device for use in presenting electronically generated visual images to a viewer. The device includes a headpiece worn by a viewer, and an image display screen mounted in the headpiece for presenting electronically generated images. A fresnel lens is positioned adjacent the screen for focusing images from the screen at a selected position for viewing as a virtual image. The lens has a set of concentric converging rings whose surface curvatures act to minimize rectilinear distortion of the virtual images perceived by the viewer over the entire field of view of the image.
    Type: Grant
    Filed: November 28, 1997
    Date of Patent: December 7, 1999
    Assignee: Sun Microsystems, Inc.
    Inventor: Michael A. Teitel
  • Patent number: 5995291
    Abstract: The invention relates to an image-forming optical system which is compact and light in weight with well corrected aberrations, and is suitable for use on an image display device designed to form no intermediate image, and an optical system. This optical system comprises a prism member and a diffraction optical element that are mutually decentered. The prism member comprises at least three juxtaposed optical surfaces, at least one of which is constructed of a curved surface. Between the optical surfaces, at least two reflections occur. Spaces between the optical surfaces arc filled with a medium having a refractive index greater than 1.
    Type: Grant
    Filed: June 30, 1998
    Date of Patent: November 30, 1999
    Assignee: Olympus Optical Co., Ltd.
    Inventor: Takayoshi Togino
  • Patent number: 5917656
    Abstract: An optical system capable of correcting aberrations due to three-dimensional decentration by using a rotationally asymmetric surface having no plane of symmetry. The optical system includes, from the ray bundle entrance sides, a first surface (3) serving as both a first transmitting surface and a second reflecting surfaces a second surface (4) as a first reflecting surfaces and a third surface (5) as a second transmitting surface. The space between these surfaces is filled with a medium having a refractive index larger than 1. The first surface (3) is a three-dimensional surface having no plane of symmetry.
    Type: Grant
    Filed: May 7, 1997
    Date of Patent: June 29, 1999
    Assignee: Olympus Optical Co., Ltd.
    Inventors: Kazuhito Hayakawa, Takayoshi Togino
  • Patent number: 5905597
    Abstract: The present invention is characterized in that when a phototaking lens system forms image information on a image pickup device in which a plurality of light-receiving elements are arranged in a non-square lattice pattern and a signal from the image pickup device is sampled in a square lattice to obtain a two-dimensional digital image, the phototaking lens system forms an image as optically correcting for a distortion of aspect ratio of image caused upon sampling in the square lattice.
    Type: Grant
    Filed: October 17, 1995
    Date of Patent: May 18, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Satoru Mizouchi, Tsunefumi Tanaka
  • Patent number: 5867327
    Abstract: Method for manufacturing cylindrical microlenses having exceptional optical properties, and the lenses manufactured according to the process. According to the present invention, a method is provided for fabricating cylindrical microlenses, the method comprising the steps of forming a glass preform by means of grinding at least one face thereof in the direction transverse to longitudinal axis of the lens, the preform having the shape of a cylindrical lens, and drawing the glass preform to reduce its cross-sectional dimensions while retaining its cross-sectional shape, thereby providing a cylindrical microlens with a high numerical aperture or other desirable characteristics. The drawing step may be facilitated by means of the application of heat to the preform. Further, the preform may be roughly formed to a shape intermediate to its finished form by casting, sintering, extruding, or other glass forming methodology.
    Type: Grant
    Filed: April 23, 1997
    Date of Patent: February 2, 1999
    Assignee: Blue Sky Research
    Inventor: James J. Snyder
  • Patent number: 5861997
    Abstract: A catadioptric projection optical system is provided, which can use a beam splitting optical system smaller in size than a conventional polarizing beam splitter, can set a long optical path from a concave reflecting mirror to an image plane, allows easy adjustment of the optical system, and has excellent imaging performance. A light beam from an object surface forms a first intermediate image through a refracting lens group. A light beam from the first intermediate image passes through a polarizing beam splitter and is reflected by a concave reflecting mirror to form a second intermediate image in the polarizing beam splitter. A light beam from the second intermediate image is reflected by the polarizing beam splitter means to form a final image on the image plane via a refracting lens group. The polarizing beam splitter means is arranged near the positions at which the intermediate images are formed.
    Type: Grant
    Filed: August 16, 1995
    Date of Patent: January 19, 1999
    Assignee: Nikon Corporation
    Inventor: Tomowaki Takahashi
  • Patent number: 5784209
    Abstract: An optical lens is disclosed that is suitable for use in a line scanner or analogous device. The lens has multiple optical axes individually corresponding to a respective refractive combination comprising a first and an opposing second refractive surface. The lens is movable, preferably by rotation about an axis, relative to an axis of light propagation so as to permit selection of a desired refractive combination by aligning the optical axis of the refractive combination with the axis of light propagation.
    Type: Grant
    Filed: May 17, 1996
    Date of Patent: July 21, 1998
    Assignee: Nikon Corporation
    Inventor: Yuji Manabe
  • Patent number: 5677796
    Abstract: An improved spherical gradient lens and a method of fabricating same. A uniform sphere of a material such as high density irradiated polystyrene or a methylpentene copolymer in the polyolefin family having a uniform relative dielectric constant is provided. A plurality of radially extending holes are formed therein, for example by drilling, the holes having a predetermined cross sectional geometry along axes extending radially from the center of the sphere. The geometry of holes is selected to control the resultant local density of material, and thus the relative dielectric constant as a function of distance from the center of the sphere. Hole diameters are chosen so as to be small compared to the shortest wavelength of interest with which the lens will be used.
    Type: Grant
    Filed: August 25, 1995
    Date of Patent: October 14, 1997
    Assignee: EMS Technologies, Inc.
    Inventors: Kurt A. Zimmerman, Donald L. Runyon
  • Patent number: 5648871
    Abstract: A projection apparatus in which in order that an original image, which is compressed in a horizontal direction, may be projected onto a screen at a predetermined location by a master lens, the original image is disposed with the center thereof deviated relative to the optical axis of the master lens and in which an anamorphic lens having an optical axis inclined with respect to the optical axis of the master lens and having refractive power in a horizontal direction is disposed on the screen side of the master lens.
    Type: Grant
    Filed: January 18, 1995
    Date of Patent: July 15, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Atsushi Okuyama, Hideo Yokota, Katsumi Azusawa
  • Patent number: 5598205
    Abstract: An imaging apparatus includes an objective lens system for forming an image of an object, a solid-state image pickup device, a signal processor and a display device. The objective lens system includes at least one revolutionally asymmetrical refractive surface for deforming the image formed by the objective lens system and is configured so as to deform further the image which is deformed by the signal processor.
    Type: Grant
    Filed: April 22, 1994
    Date of Patent: January 28, 1997
    Assignee: Olympus Optical Co., Ltd.
    Inventor: Kimihiko Nishioka
  • Patent number: 5559629
    Abstract: A Dyson lens system includes a radiation source, a concave mirror, and a plano-convex lens. There is also incorporated in the system an additional lens that is spaced from the plano-convex lens a large part of the distance from the plano-convex lens to the mirror. A roof prism and a turning prism are provided to conduct radiation from the radiation source to the plano-convex lens and also from the plano-convex lens to an image plane. An image adjustor or compensator is provided between the prisms and either the image plane or an object plane--the latter being disposed between the radiation source and the prisms. An adjustment mechanism is provided to effect highly accurate adjustment of the location of the image, the adjustment mechanism including physical shifting to a slight degree of a portion of one or both prisms.
    Type: Grant
    Filed: November 30, 1994
    Date of Patent: September 24, 1996
    Assignee: Tamarack Scientific Co., Inc.
    Inventors: Ronald E. Sheets, Yanrong Yuan
  • Patent number: 5553178
    Abstract: The present invention provides an asymmetrical lens showing different sets of optical characteristics as projected on two planes that are parallel to the optical axis of the lens and perpendicular to each other and satisfying the following simultaneous system of equations.(w.perp.2)/(w.perp.1)=(f.perp.2)/(f.perp.1) [2](w.parallel.2)/(w.parallel.1)32 (f.parallel.2)/(f.parallel.1)[3](d.perp.1)=.vertline.(s.perp.1).vertline.(s.parallel.1) [4](d2)=.vertline.(s.perp.2)-(s.parallel.
    Type: Grant
    Filed: April 22, 1994
    Date of Patent: September 3, 1996
    Assignee: The Furukawa Electric Co., Ltd.
    Inventor: Shu Namiki
  • Patent number: 5381266
    Abstract: A stereoviewer for observing a stereo pair of photographs three-dimensionally through binocular lenses is shown and described. The stereoviewer comprises a box-shaped main body case having a space for accommodating stereoscopic photographs; a lid for covering the main body case; holder portions provided on one side surface of the box-shaped main body case so as to position and hold the stereoscopic photographs in a non-perpendicular standing state; and binocular lenses provided thereon are inclined in such a manner that the binocular lenses face the vertical center portion of the stereoscopic photographs. This stereoviewer also serves as a package and has a simple structure. The thickness of the binocular lenses are varied so that the focal distance is different between the upper portion and the lower portion of said binocular lenses and the binocular lenses are decentered outwardly in the horizontal direction.
    Type: Grant
    Filed: February 9, 1993
    Date of Patent: January 10, 1995
    Assignee: Fuji Photo Optical Co., Ltd.
    Inventors: Shigeo Mizukawa, Tsuneo Yokoyama
  • Patent number: 5280386
    Abstract: The invention relates to a windshield deflector shield for deflecting insects and debris above the hood and windshield of a vehicle and for increasing the driver's field of vision. The deflector shield includes a lens coupled to the middle deflector section for increasing the field of vision in front of the vehicle. The deflector shield may also include rearview mirrors coupled to the ends of the deflector shield for increasing the driver's field of vision at the sides of the vehicle.
    Type: Grant
    Filed: July 10, 1991
    Date of Patent: January 18, 1994
    Assignee: Paccar Inc.
    Inventor: Douglas P. Johnson
  • Patent number: 5241423
    Abstract: An optical system of a NX reduction catadioptric relay lens having sub-half micron resolution over the ultraviolet band width is described. A spherical mirror with a stop at the mirror is used to work at substantially the desired reduction ratio and the desired high numerical aperture sufficient to provide the desired high resolution. A beam splitting cube with appropriate coatings is used to form an accessible image of an object on an image plane. Refracting correctors in the path of the slow beam incident on the mirror and in the path of the fast beam reflected on the mirror are designed to fix the aberrations of the image formed by the mirror.
    Type: Grant
    Filed: August 1, 1991
    Date of Patent: August 31, 1993
    Assignee: International Business Machines Corporation
    Inventors: George L. Chiu, Rama N. Singh, Janusz S. Wilczynski
  • Patent number: 5218470
    Abstract: A stereoviewer for observing a stereo pair of photographs three-dimensionally through binocular lenses is shown and described. The stereoviewer comprises a box-shaped main body case having a space for accommodating stereoscopic photographs; a lid for covering the main body case; holder portions provided on one side surface of the box-shaped main body case so as to position and hold the stereoscopic photographs in a non-perpendicular standing state; and binocular lenses provided thereon are inclined in such a manner that the binocular lenses face the vertical center portion of the stereoscopic photographs. This stereoviewer also serves as a package and has a simple structure. The thickness of the binocular lenses are varied so that the focal distance is different between the upper portion and the lower portion of said binocular lenses and the binocular lenses are decentered outwardly in the horizontal direction.
    Type: Grant
    Filed: December 26, 1991
    Date of Patent: June 8, 1993
    Assignee: Fuji Photo Optical Co., Ltd.
    Inventors: Shigeo Mizukawa, Tsuneo Yokoyama
  • Patent number: 5173723
    Abstract: A multifocal lens configuration is disclosed having a lens body with first and second surfaces wherein at least one of the surfaces is defined three dimensionally as being rotationally non-symmetric about the optical axis of the lens. The lens surface may be described and modeled as having angular zones or sectors of differing curvature responsible for near, intermediate or distance vision or combinations thereof. The lens surface is defined by a plurality of individually defined semi-meridian sections radiating centrifugally from the apical umbilical point or polar axis of the lens surface, wherein each of the semi-meridian sections are tangent to one another at the apical umbilical point and form a continuous smooth surface in conjunction with one another. Each of the semi-meridian sections may be differently and uniquely shaped, and are defined according to shape and magnitude, wherein the semi-meridian sections within an angular zone may be constant or may vary in a continuous and regular manner.
    Type: Grant
    Filed: October 2, 1990
    Date of Patent: December 22, 1992
    Inventor: Donald A. Volk
  • Patent number: 5159491
    Abstract: An optical element for collimating and rectifying divergent incident radiation comprises a first optical surface and a second optical surface titled with respect to the first optical surface. The first optical surface has sufficient power to collimate incident radiation, while the second optical surface is tilted sufficiently to provide rectification.
    Type: Grant
    Filed: February 20, 1990
    Date of Patent: October 27, 1992
    Assignee: Eastman Kodak Company
    Inventor: David A. Richards
  • Patent number: 5157535
    Abstract: An optical system having a single, monolithic scan element as shown in the drawing in which surface 6 is concave, surface 7 is convex, surface 8 is convex, surface 9 is convex and the circumference of surface 9 is convex, surface 10 is convex, surface 11 is convex, and surface 13 is flat. f-theta correction is made primarily at surfaces 6, 9, 10 and 13. The element is molded from optical grade plastic and provides improved performance, no assembly adjustment, performance enhancement from its complex surfaces, and low cost.
    Type: Grant
    Filed: January 29, 1992
    Date of Patent: October 20, 1992
    Assignee: Lexmark International, Inc.
    Inventors: Philip J. Heink, Daniel L. Huber, Wilson M. Routt, Jr., Scott S. Williams
  • Patent number: 5134526
    Abstract: A focus detecting optical system comprises two imaging optical systems which are composed of an integrally molded prism, and is adapted to perform focus detection on the basis of relative positional relationship between an image of an object formed with one of the imaging optical systems and another image of the object formed with the other imaging optical system. Ineffective optical path regions of the surfaces of the prism which allow transmission or reflection of the rays entering the prism are designed as light diffusing surfaces and/or surfaces coated with a light absorption substance. An aperture stop arranged before each surface of incidence of light is arranged eccentrically with regard to the optical axis of incident rays or each surface of incidence of light has a refractive power asymmetrical with regard to said optical axis so that all the rays incident on the totally reflecting surfaces arranged in the two imaging optical systems are totally reflected.
    Type: Grant
    Filed: December 28, 1990
    Date of Patent: July 28, 1992
    Assignee: Olympus Optical Co., Ltd.
    Inventor: Tatsuo Inabata
  • Patent number: 5094520
    Abstract: An axiosymmetric eccentric spherical polycarbonate lens (2) for goggles (1), comprising inner (7) and outer (8) spherical surfaces defined by centers of curvature 0.sub.1 and 0.sub.2 and by radii R.sub.1 and R.sub.2, respectively, 0.sub.1 and 0.sub.2 being both located on the lens's axis of symmetry (5), at a distance D from each other, the lens being more distal from 0.sub.1 than from 0.sub.2, the length of R.sub.2 being about 1.025-1.035 R.sub.1, and that of D about 0.0510-0.0564.
    Type: Grant
    Filed: February 22, 1991
    Date of Patent: March 10, 1992
    Assignee: Bezalel Research and Development Ltd.
    Inventors: Yaron Reshef, Uri Alon
  • Patent number: 5081639
    Abstract: The present invention provides a diffraction limited, high numerical aperture (fast) cylindrical microlens. The method for making the microlens is adaptable to produce a cylindrical lens that has almost any shape on its optical surfaces. The cylindrical lens may have a shape, such as elliptical or hyperbolic, designed to transform some particular given input light distribution into some desired output light distribution. In the method, the desired shape is first formed in a glass preform. Then, the preform is heated to the minimum drawing temperature and a fiber is drawn from it. The cross-sectional shape of the fiber bears a direct relation to the shape of the preform from which it was drawn. During the drawing process, the surfaces become optically smooth due to fire polishing.
    Type: Grant
    Filed: October 1, 1990
    Date of Patent: January 14, 1992
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: James J. Snyder, Patrick Reichert
  • Patent number: 5073017
    Abstract: A telephoto lens is provided, in succession from the object side to the image surface side, with a first lens component having a positive refractive power and a second lens component having a negative refractive power. At least one curved lens surface of the second lens component is inclined relative to the optic axis to thereby deflect the image. Particularly the lens surface which near the image surface is inclined.
    Type: Grant
    Filed: November 13, 1989
    Date of Patent: December 17, 1991
    Assignee: Canon Kabushiki Kaisha
    Inventor: Shigeyuki Suda