With Lamp Focusing Patents (Class 356/122)
  • Patent number: 9700957
    Abstract: Methods of fabricating reduced weight components for apparatuses include providing a plurality of layers from a component core including a relatively lightweight material to an outer layer including a relatively heavyweight material heavier in weight than the relatively lightweight material, the plurality of layers having increasingly higher proportions of the relatively heavyweight material than the relatively lightweight material from the component core to the outer layer; and diffusion bonding the plurality of layers and the outer layer by consolidation of the layers.
    Type: Grant
    Filed: September 25, 2014
    Date of Patent: July 11, 2017
    Inventor: Steven P. Burgess
  • Patent number: 8988672
    Abstract: A method of aiming a light source includes using an image-capturing device to capture a light beam pattern from the light source. Here, the light beam pattern is configured to include a plurality of contrast ratios transitioning from a first intensity region to a second intensity region. The method includes processing the contrast ratios of the light beam pattern to obtain corresponding values of the contrast ratios, transitioning from the first intensity region to the second intensity region, where the corresponding values are logarithmic values, which in turn generate a related response curve. Finally, the method provides for using the logarithmic values and the response curve to aim the light source.
    Type: Grant
    Filed: July 13, 2012
    Date of Patent: March 24, 2015
    Assignee: Ford Global Technologies, LLC
    Inventors: John Wesley Wilds, Michael Wegrzyn, Stephanie Askew, Albert Ekladyous, Arun Kumar, Diane Marie LaHaie
  • Patent number: 8891077
    Abstract: A wavefront measuring method using a Shack-Hartmann sensor includes the steps of provisionally determining one of a plurality of light receiving elements as a center-of-gravity position in a spot having a light intensity distribution of light condensed on the light receiving element, calculating a distance between the provisionally determined center-of-gravity position and an adjacent center-of-gravity position, setting an area smaller than and inside of a spot that partially overlaps another spot, and setting a spot that does not overlap another spot to the area, calculating a center-of-gravity position for each area, and calculating the wavefront based upon a shift amount between an ideal center-of-gravity position when parallel light enters the micro lens array and the center-of-gravity position of each area.
    Type: Grant
    Filed: August 9, 2013
    Date of Patent: November 18, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yuuichi Takaie
  • Patent number: 8848178
    Abstract: An in-line laser beam waist analyzer system includes an optical prism that picks off a portion of a second surface reflection from either a laser processing focus lens or a protective debris shield for the processing lens and directs that focused light to a pixelated detector. This provides real time monitoring of the focused laser beam while it is processing material by welding, cutting, drilling, scribing or marking, without disrupting the process.
    Type: Grant
    Filed: April 28, 2014
    Date of Patent: September 30, 2014
    Assignee: Haas Laser Technologies, Inc.
    Inventor: Michael J. Scaggs
  • Patent number: 8848179
    Abstract: An in-line laser beam waist analyzer system includes an optical prism that picks off a portion of a second surface reflection from either a laser processing focus lens or a protective debris shield for the processing lens and directs that focused light to a pixelated detector. This provides real time monitoring of the focused laser beam while it is processing material by welding, cutting, drilling, scribing or marking, without disrupting the process.
    Type: Grant
    Filed: April 28, 2014
    Date of Patent: September 30, 2014
    Assignee: Haas Laser Technologies, Inc.
    Inventor: Michael J. Scaggs
  • Patent number: 8848177
    Abstract: An in-line laser beam waist analyzer system includes an optical prism that picks off a portion of a second surface reflection from either a laser processing focus lens or a protective debris shield for the processing lens and directs that focused light to a pixelated detector. This provides real time monitoring of the focused laser beam while it is processing material by welding, cutting, drilling, scribing or marking, without disrupting the process.
    Type: Grant
    Filed: April 28, 2014
    Date of Patent: September 30, 2014
    Assignee: Haas Laser Technologies, Inc.
    Inventor: Michael J. Scaggs
  • Patent number: 8836928
    Abstract: Providing a method for measuring wavefront aberration measured by detecting light that is emanated from a light source, incident on a test lens, and transmitted through the test lens, the method comprising steps of: measuring wavefront aberration in a state where an aperture stop of the test lens is fully opened; measuring a position of the center of a pupil of the test lens in a state where the aperture stop is stopped down; and expanding wavefront aberration by polynomials with making the position of the center of the pupil to be an origin, and a wavefront aberration measuring apparatus.
    Type: Grant
    Filed: October 19, 2010
    Date of Patent: September 16, 2014
    Assignee: Nikon Corporation
    Inventor: Issei Tanaka
  • Patent number: 8780361
    Abstract: In an embodiment of the disclosure, there is provided an apparatus for calibrating a laser projection system. The apparatus has a structural frame assembly extending along three mutually orthogonal axes. The apparatus further has a plurality of non-movable reflective targets disposed on the structural frame assembly. The apparatus further has at least three positioning stages coupled to the structural frame assembly respectively about each of the three mutually orthogonal axes. At least one movable reflective target is disposed on each positioning stage. The non-movable reflective targets and the at least one movable reflective target are each configured to reflect a laser beam from a laser projection system.
    Type: Grant
    Filed: February 3, 2012
    Date of Patent: July 15, 2014
    Assignee: The Boeing Company
    Inventors: Curtis M. Ashford, Brian A. Bollinger
  • Patent number: 8736827
    Abstract: A system for obtaining a propagation factor for determining the performance of a light beam (32) includes a light sensor (10), a lens element (30) operable to focus a beam from a light source to be tested towards the sensor element (10); wherein the lens element is a variable focus lens (30).
    Type: Grant
    Filed: April 28, 2010
    Date of Patent: May 27, 2014
    Assignee: The Secretary of State for Business Innovation and Skills of Her Majesty's Brittannic Government
    Inventor: Simon Richard Geoffrey Hall
  • Patent number: 8711343
    Abstract: An in-line laser beam waist analyzer system includes an optical prism that picks off a portion of a second surface reflection from either a laser processing focus lens or a protective debris shield for the processing lens and directs that focused light to a pixelated detector. This provides real time monitoring of the focused laser beam while it is processing material by welding, cutting, drilling, scribing or marking, without disrupting the process.
    Type: Grant
    Filed: October 22, 2012
    Date of Patent: April 29, 2014
    Assignee: Haas Laser Technologies, Inc.
    Inventor: Michael J. Scaggs
  • Patent number: 8670112
    Abstract: Disclosed is a method for operating a test apparatus for an LED lamp. The method includes: forming a self-holding circuit by switching on a first switching means such that an up and down shifter provided in the test apparatus for the LED lamp moves down; moving down and stopping the up and down shifter from a determined initial position to a measurement position; measuring the quality of the LED lamp equipped with the test apparatus for the LED lamp; releasing the self-holding circuit by switching on the second switching means such that the up and down shifter moves up; and moving up and down shifter from the measurement position to the determined initial position.
    Type: Grant
    Filed: January 6, 2011
    Date of Patent: March 11, 2014
    Assignee: LG Innotek Co., Ltd.
    Inventors: Sungho Hong, Jang Gu Oh, Tae Young Choi, Jong Tae Park
  • Publication number: 20140009753
    Abstract: A wavefront aberration measuring apparatus comprising: an illumination optical system provided to an incident side of a test lens; and a measuring optical system provided to an exit side of the test lens, the illumination optical system including an aperture stop capable of being opened and closed, and the illumination optical system being movable along an optical axis of the illumination optical system so as to adjust positions of the aperture stop and an entrance pupil of the test lens to have an optically conjugate relation with each other. Accordingly, it becomes possible to provide a wavefront aberration measuring apparatus capable of suppressing errors in measured result.
    Type: Application
    Filed: September 10, 2013
    Publication date: January 9, 2014
    Applicant: Nikon Corporation
    Inventor: Tatsuro OTAKI
  • Publication number: 20130188178
    Abstract: A method of optimising the focus of a fibre laser is described, which comprises positioning the output of a fibre laser relative to a workpiece; measuring at least a portion of back reflected radiation from the workpiece (step 52); determining an integral of this; changing the relative position of the output and the workpiece one or more times (step 54,56), each time determining an integral of values for the back-reflection, and using the integrals to determine optimum focus.
    Type: Application
    Filed: July 19, 2011
    Publication date: July 25, 2013
    Applicant: GSI Group Limited
    Inventor: Steve Keen
  • Patent number: 8492682
    Abstract: A micro heater includes a first electrode, a second electrode, a first carbon nanotube, and a second carbon nanotube. The first carbon nanotube extends from the first electrode. The second carbon nanotube branches from the second electrode. The first carbon nanotube and the second carbon nanotube intersect with each other to define a node therebetween.
    Type: Grant
    Filed: December 30, 2010
    Date of Patent: July 23, 2013
    Assignees: Tsinghua University, Hon Hai Precision Industry Co., Ltd.
    Inventors: Xue-Shen Wang, Qun-Qing Li, Shou-Shan Fan
  • Patent number: 8427633
    Abstract: An apparatus that enables real time measurement of the spatial profile, circularity, centroid, astigmatism and M2 values of a laser beam generated by a high power laser beam. The apparatus employs the optics used in a process application, including a focus lens and cover glass. An attenuation module includes a pair of high reflecting mirror plates disposed in parallel, spaced apart relation to one another at a common angle of incidence to the laser beam. A beam dump is positioned out of a path of travel of the laser beam and in receiving relation to light reflected by the first and second mirrors. A camera detects spots of light that pass through the first and second mirrors. A high power attenuator formed by a highly reflective mirror pair is positioned between the source and the attenuation module. A second embodiment includes a single mirror plate having highly reflective surfaces.
    Type: Grant
    Filed: May 25, 2012
    Date of Patent: April 23, 2013
    Assignee: Haas Laser Technologies, Inc.
    Inventor: Michael J. Scaggs
  • Patent number: 8351028
    Abstract: According to an embodiment, a measuring device for measuring a laser beam comprises a magnification lens system with a total of two lenses which are arranged in series in the beam path of the laser beam and whose foci are coinciding, as well as a camera which is arranged behind the two lenses in the focus of the last lens and includes an electronic image sensor which generates an electronic image of the magnified laser beam. The lenses together with the camera are adjustable along the beam path relative to a reference point of the measuring device, for the purpose of locating the beam waist of the laser beam and of determining a diameter profile of the laser beam. The measuring device further comprises an adapter enclosing the beam path for coupling the measuring device to a laser system which provides the laser beam.
    Type: Grant
    Filed: September 12, 2008
    Date of Patent: January 8, 2013
    Assignee: Wavelight GmbH
    Inventors: Bernd Zerl, Olaf Kittelmann
  • Patent number: 8289504
    Abstract: A Shack Hartmann (“SH”) wavefront sensor comprising an optical device, such as a wave front dissector including a lenslet array, for transmitting, dissecting and focusing an incoming optical wave, an optical system, including, for example, an optical sensor, for receiving the transmitted incoming optical wave, and a removable kinematic mount for repeatable precision mounting of the optical device to the optical system.
    Type: Grant
    Filed: July 20, 2010
    Date of Patent: October 16, 2012
    Assignee: Thorlabs, Inc.
    Inventors: Alex E. Cable, Egbert Krause, John Taranto
  • Publication number: 20120206719
    Abstract: Providing a method for measuring wavefront aberration measured by detecting light that is emanated from a light source, incident on a test lens, and transmitted through the test lens, the method comprising steps of: measuring wavefront aberration in a state where an aperture stop of the test lens is fully opened; measuring a position of the center of a pupil of the test lens in a state where the aperture stop is stopped down; and expanding wavefront aberration by polynomials with making the position of the center of the pupil to be an origin, and a wavefront aberration measuring apparatus.
    Type: Application
    Filed: October 19, 2010
    Publication date: August 16, 2012
    Applicant: NIKON CORPORATION
    Inventor: Issei Tanaka
  • Patent number: 8237922
    Abstract: An apparatus that enables real time measurement of the spatial profile, circularity, centroid, astigmatism and M2 values of a laser beam generated by a high power laser beam. The apparatus employs the optics used in a process application, including a focus lens and cover glass. An attenuation module includes a pair of high reflecting mirror plates disposed in parallel, spaced apart relation to one another at a common angle of incidence to the laser beam. A beam dump is positioned out of a path of travel of the laser beam and in receiving relation to light reflected by the first and second mirrors. A camera detects spots of light that pass through the first and second mirrors. A high power attenuator formed by a highly reflective mirror pair is positioned between the source and the attenuation module. A second embodiment includes a single mirror plate having highly reflective surfaces.
    Type: Grant
    Filed: April 8, 2010
    Date of Patent: August 7, 2012
    Assignee: Haas Laser Technologies, Inc.
    Inventor: Michael J. Scaggs
  • Publication number: 20120086936
    Abstract: A system for obtaining a propagation factor for determining the performance of a light beam (32) includes a light sensor (10), a lens element (30) operable to focus a beam from a light source to be tested towards the sensor element (10); wherein the lens element is a variable focus lens (30).
    Type: Application
    Filed: April 28, 2010
    Publication date: April 12, 2012
    Applicant: The Secretary of State foer Business Innovation ans skills of /herMajesty's Britannic Government
    Inventor: Simon Richard Geoffrey Hall
  • Patent number: 8125628
    Abstract: A light baffle arrangement for sensors is used to limit the sensing field of view. Arranging multiple said limited view sensors in a linear array provides a means to accurately locate and analyze the position of a beam pattern along said array axis as in checking vehicle headlamp beam alignment.
    Type: Grant
    Filed: January 17, 2009
    Date of Patent: February 28, 2012
    Inventor: Joe J. Lones
  • Publication number: 20110317153
    Abstract: A method and apparatus for determining a focus point of a laser system is described. A reference datum surface is aligned with a laser emitter arranged to emit a laser beam. A portion of the laser beam reflects from the reference datum surface and is captured by a photon detector. Based upon the captured photons, intensity level data is generated each time the laser emitter is moved relative to the reference datum surface. A maximum intensity level is then determined in accordance with the distance moved by the laser emitter associated with the focus point of the laser system. In some cases, an interpolation is performed to provide a more accurate determination of the location of the focus point, the interpolation being in one case a second order polynomial.
    Type: Application
    Filed: June 24, 2010
    Publication date: December 29, 2011
    Applicant: APPLE INC.
    Inventor: Michael Bruce Holmberg
  • Patent number: 8064058
    Abstract: A disclosed optical testing apparatus comprises: a plurality of optical fibers, each optical fiber having a collection end in optical communication with an output end; and a support member supporting the collection ends of the optical fibers so as to simultaneously view an examination region from different angles. A disclosed optical testing apparatus comprises a plurality of optical fibers having collection ends arranged to simultaneously view an examination region from a plurality of different angles. A disclosed optical testing apparatus comprises a plurality of optical fibers, each optical fiber having a collection end, the collection ends of the optical fibers arranged in fixed spatial relationship respective to one another to simultaneously view an examination region from different angles.
    Type: Grant
    Filed: July 15, 2008
    Date of Patent: November 22, 2011
    Assignee: GE Lighting Solutions, LLC
    Inventors: Boris Kolodin, Emil Radkov, Mark J. Mayer
  • Publication number: 20100253937
    Abstract: According to an embodiment, a measuring device for measuring a laser beam comprises a magnification lens system with a total of two lenses which are arranged in series in the beam path of the laser beam and whose foci are coinciding, as well as a camera which is arranged behind the two lenses in the focus of the last lens and includes an electronic image sensor which generates an electronic image of the magnified laser beam. The lenses together with the camera are adjustable along the beam path relative to a reference point of the measuring device, for the purpose of locating the beam waist of the laser beam and of determining a diameter profile of the laser beam. The measuring device further comprises an adapter enclosing the beam path for coupling the measuring device to a laser system which provides the laser beam.
    Type: Application
    Filed: September 12, 2008
    Publication date: October 7, 2010
    Applicant: WAVELIGHT AG
    Inventors: Bernd Zerl, Olaf Kittelmann
  • Patent number: 7612876
    Abstract: A measure of the quality of a laser beam is obtained by comparing the power of a theoretical Gaussian beam through a (certain sized area) pinhole to the power of a test beam through a same sized (area) pinhole. The theoretical surrogate Gaussian beam with the same second moment of intensity as the test beam is used to determine the “bucket size” used in “power-in-the-bucket” techniques. The bucket size is an interaction area determined by the wavelength of the laser light, the focusing distance, and the 1/e2 radius of the near field intensity. The beam quality is determined by taking the square root of the ratio of the theoretical power through a bucket and the actual power through a pinhole with the same size as the bucket. The beam quality of different types of beam profiles can be obtained with a single method or measure.
    Type: Grant
    Filed: May 29, 2008
    Date of Patent: November 3, 2009
    Assignee: The Boeing Company
    Inventor: Kenneth C. Widen
  • Patent number: 7072030
    Abstract: An optical sheet optimization method includes the steps of: extracting a statistic sample using transmissivity, haze data and luminance data of an optical diffusion sheet corresponding to the transmissivity and the haze data; making a regression model for the extracted statistic sample; calculating a regression coefficient to minimize an error term (residual) of the regression model and deriving a regression expression using the calculated regression coefficient; and predicting a luminance of the optical diffusion sheet due to changes of the transmissivity and the haze data using the derived regression expression.
    Type: Grant
    Filed: October 29, 2003
    Date of Patent: July 4, 2006
    Assignee: LG.Philips LCD Co., Ltd.
    Inventors: Don Gyou Lee, Ki Yon Song, Soon Ho Lee, Jang Ryang Kim
  • Patent number: 6765660
    Abstract: A system is disclosed for analyzing an illumination field of a line of laser illumination. The system includes a first movable unit, a second movable unit, and a sensor unit. The first movable unit includes a first opening through which at least a portion of the illumination field may pass. The first movable unit is adapted for movement in a first direction. The sensor unit is adapted to receive illumination and to produce a sensor output signal representative a characteristic of the illumination field. The second movable unit includes a second opening through which at least a portion of the illumination field may pass. The second movable unit is positioned between the first movable unit and the sensor unit and is adapted for movement between at least a first position in which very little or no light from the illumination field may reach the sensor unit, and a second position in which a relatively high amount of light from the illumination field may reach the sensor unit.
    Type: Grant
    Filed: April 28, 2003
    Date of Patent: July 20, 2004
    Assignee: Agfa Corporation
    Inventor: John F. Nolan
  • Publication number: 20040125362
    Abstract: An optical sheet optimization method includes the steps of: extracting a statistic sample using transmissivity, haze data and luminance data of an optical diffusion sheet corresponding to the transmissivity and the haze data; making a regression model for the extracted statistic sample; calculating a regression coefficient to minimize an error term (residual) of the regression model and deriving a regression expression using the calculated regression coefficient; and predicting a luminance of the optical diffusion sheet due to changes of the transmissivity and the haze data using the derived regression expression.
    Type: Application
    Filed: October 29, 2003
    Publication date: July 1, 2004
    Applicant: LG.PHILIPS LCD CO., LTD.
    Inventors: Don Gyou Lee, Ki Yon Song, Soon Ho Lee, Jang Ryang Kim
  • Patent number: 6646728
    Abstract: The invention relates in general to calibrating a focused beam of energy in a solid freeform fabrication apparatus, and, in particular, to a method of measuring the propagation characteristics of the beam to produce beam propagation data. The beam propagation data can be used to verify that the beam is operating within tolerance, and/or produce a response that can be used to further calibrate the beam. The invention is particularly useful in determining asymmetric conditions in the beam. The beam propagation data is produced in accord with the “M2” standard for characterizing a beam. In one embodiment, the response indicates the beam is unacceptable for use in the apparatus. In another embodiment, the response is provided to calibrate the focal position of the beam. In still another embodiment, the response is provided to an adjustable beam that eliminates the asymmetric condition.
    Type: Grant
    Filed: July 9, 2001
    Date of Patent: November 11, 2003
    Assignee: 3D Systems, Inc.
    Inventors: Nansheng Tang, Jouni P. Partanen
  • Patent number: 6618131
    Abstract: A system is disclosed for analyzing an illumination field of a line of laser illumination. The system includes a first movable unit, a second movable unit, and a sensor unit. The first movable unit includes a first opening through which at least a portion of the illumination field may pass. The first movable unit is adapted for movement in a first direction. The sensor unit is adapted to receive illumination and to produce a sensor output signal representative a characteristic of the illumination field. The second movable unit includes a second opening through which at least a portion of the illumination field may pass. The second movable unit is positioned between the first movable unit and the sensor unit and is adapted for movement between at least a first position in which very little or no light from the illumination field may reach the sensor unit, and a second position in which a relatively high amount of light from the illumination field may reach the sensor unit.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: September 9, 2003
    Assignee: Agfa Corporation
    Inventor: John F. Nolan
  • Patent number: 5877853
    Abstract: A method of measuring the radius of curvature of the convex tip of a core protruding from the end of an optical transmission path is disclosed. The transmission path is implemented by an optical fiber. A measuring unit accommodating a condenser and an infrared camera is located to face the convex tip of the core. A semiconductor laser is connected to the end of the fiber remote from the convex tip. A laser beam issuing from the convex tip of the core is once condensed by the convex tip. The measuring unit determines the condensing point of the beam, and then measures the distance between the condensing point and the convex tip. Subsequently, after the space between the convex tip and the condenser has been filled with a medium different in refractive index from air, the measuring unit again measures the above distance. The radius of curvature of the convex tip is determined on the basis of a difference or a radio between the measured distances.
    Type: Grant
    Filed: April 1, 1997
    Date of Patent: March 2, 1999
    Assignee: NEC Corporation
    Inventor: Hiroshi Honmou
  • Patent number: 5647031
    Abstract: A device is provided for checking the positioning and/or the focusing of a focused light beam. This integrated optical device for checking the positioning and/or the focusing of a focused light beam having an integrated optics guidance structure includes a multimode waveguide or an array of monomode guides distributed so as to be able to exchange energy. The waveguide or monomode guide array is integrated into the guidance structure and is able, when the distribution of the light beam directed at the input of the guide or the array of guides has a single maximum, to transform the distribution into a distribution having N (N.gtoreq.2) maxima at the output of the guide or array of guides. The guideance structure fruther includes a detector for measuring the distribution of the intensity at the output of the waveguide or monomode guide array, and an analyzer for analyzing the intensity distribution connected to the detector.
    Type: Grant
    Filed: April 24, 1995
    Date of Patent: July 8, 1997
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Valerie Lapras, Pierre Gidon, Patrick Pouteau
  • Patent number: 5619322
    Abstract: That illuminating pattern of the headlight which appears on a screen disposed in front of the vehicle is pictured. The optical axis of the headlight is adjusted based on an image of the illuminating pattern. A distribution of illuminance of the illuminating pattern along a scanning line which bridges a light portion and a dark portion of the image of the illuminating pattern is measured. A position of a reference point which serves as a reference in adjusting the optical axis is obtained from that point on the scanning line which corresponds to a crossing point of a first straight line and a second straight line. The first straight line is obtained from a portion corresponding at least to one of the light portion and the dark portion of a curve which represents the measured distribution of illuminance. The second straight line is obtained from a portion corresponding to a transient region which is positioned between the light portion and the dark portion.
    Type: Grant
    Filed: March 28, 1995
    Date of Patent: April 8, 1997
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Nagatoshi Murata, Hisaya Ooiwa, Takeshi Masaki
  • Patent number: 5056916
    Abstract: An optical axis adjusting system comprises at least one lighting unit such as a vehicle's head lamp unit, and at least one optical instrument. The lighting unit comprises a housing having a reflector, and a lens having first and second portions which are positioned so that the first and second portions intersect, respectively, imaginery first and second straight lines that are parallel to the optical axis of the lighting unit and symmetrical with respect to the optical axis. The optical instrument has a light projecting unit for projecting a light beam such as a laser beam to the reflector through the first portion of the lens, and a light receiving unit for receiving a reflected beam reflected from the reflector and transmitted through the second portion of the lens. The lighting unit has at least one adjusting screw by which the aim of the lighting unit is adjusted so that reflected beam is correctly received by the receiving unit.
    Type: Grant
    Filed: September 24, 1990
    Date of Patent: October 15, 1991
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Yoichi Kikuchi, Miyoshi Iwamoto
  • Patent number: 4871947
    Abstract: Disclosed is an apparatus for stabilizing the light output of a high pressure discharge lamp comprising a coil generating a magnetic field acting upon the arc of the high pressure discharge lamp, an arc position detector detecting deviation of the position of the arc, and a magnetic field control circuit controlling the coil in response to the deviation detection output signal of the the arc position detector thereby setting right the position of the arc of the high pressure discharge lamp.
    Type: Grant
    Filed: June 13, 1988
    Date of Patent: October 3, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Tsune Miyashita, Makoto Yasuda
  • Patent number: 4455085
    Abstract: A method and apparatus for detecting a focussing error signal of an objective lens with respect to a video disc on which a light beam emitted from a laser light source is to be focussed as a light spot by the objective lens. A light flux reflected by the video disc is made incident upon a detection prism surface which is set substantially at a critical angle with respect to a central light ray in the reflected light flux, and two light fluxes which situate on respective sides of a boundary plane including the central light ray and perpendicular to a plane of incidence, and are reflected by the reflection surface are separately received by two light receiving regions which are divided along a boundary plane including the central light ray reflected by the reflection surface and perpendicular to the plane of incidence. The focussing error signal is derived as a difference between output signals from the two light receiving regions.
    Type: Grant
    Filed: August 14, 1981
    Date of Patent: June 19, 1984
    Assignee: Olympus Optical Co. Ltd.
    Inventors: Kiichi Kato, Kenichi Ito, Tohru Musha
  • Patent number: 4009966
    Abstract: A headlamp with a parabolic reflector has a filament mounted on lead wires attached to a support disc which is slidably and angularly adjustable within a cylindrical ferrule attached to the reflector so as to permit positioning the filament at the reflector focal point whereupon light from the filament will be reflected as a parallel beam from the reflector. The invention contemplates an improved method for focusing the filament including locating a planar mirror on the optical axis of the parabolic reflector for redirecting light parallel to the optical axis from the reflector back to the focal point of the mirror and wherein terminals of the filament are electrically connected to a power supply and to a meter to detect electrical resistance changes in the filament to indicate location of the filament at the focal point where light rays reflected from the flat planar mirror directly impinge on the filament to cause increase in its electrical resistance.
    Type: Grant
    Filed: September 24, 1975
    Date of Patent: March 1, 1977
    Assignee: General Motors Corporation
    Inventor: Gale M. Craig
  • Patent number: 3969575
    Abstract: In an opto-electronic focus detection system for determining a deviation between the plane of focussing of an objective and a radiation-reflecting surface the path of a focussing beam which is reflected by said surface includes an assembly of two radiation-sensitive detection elements. The difference in the output signals of said elements is proportional to said deviation. By disposing a lenslike element of which only the outer zone has a lens action before the detection elements, the measuring range can be extended while maintaining the sensitivity for small deviations.
    Type: Grant
    Filed: December 6, 1974
    Date of Patent: July 13, 1976
    Assignee: U.S. Philips Corporation
    Inventors: Gerrit Berend Gerritsen, Gerard Eduard VAN Rosmalen