Using Fourier Transform Spatial Filtering Patents (Class 359/559)
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Patent number: 7391570Abstract: A programmable optical processing device employing a plurality of controllable light modulator elements. First and second optical elements are positioned to create an optical region therebetween comprising a Fourier transform plane and at least one non-Fourier optical region from the Fourier transform plane. In one embodiment at least one of these non-Fourier optical regions comprises fractional Fourier regions. Multiple controllable light modulator elements located in a non-Fourier optical region may be adjacently stacked, spatially separated, or separated by GRIN material. The controllable light modulator elements further implement optical transfer functions that are positive-definite or non-positive-definite, and which may be controlled by electrical and/or optical control signals. In one embodiment the system may comprise a monolithic device and/or be comprised by a monolithic device.Type: GrantFiled: December 5, 2005Date of Patent: June 24, 2008Inventor: Lester F. Ludwig
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Publication number: 20080137193Abstract: An exemplary optical plate includes a first transparent layer (21), a second transparent layer (23) and a light diffusion layer (22). The first transparent layer includes an outer surface (210) and a plurality of first conical frustum protrusions (211) protruding out from the outer surface. The second transparent layer includes an outer surface (230) and a plurality of second conical frustum protrusions (231) formed at the outer surface. The first transparent layer, the light diffusion layer, and the second transparent layer are integrally formed, with the first transparent layer in immediate contact with the light diffusion layer, and the second transparent layer in immediate contact with the light diffusion layer. The light diffusion layer includes a transparent matrix resin (221) and a plurality of diffusion particles (222) dispersed in the transparent matrix resin.Type: ApplicationFiled: April 6, 2007Publication date: June 12, 2008Applicant: HON HAI precision Industry CO., LTD.Inventors: Tung-Ming Hsu, Shao-Han Chang
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Patent number: 7365917Abstract: An imaging arrangement and method for extended the depth of focus are provided. The imaging arrangement comprises an imaging lens having a certain affective aperture, and an optical element associated with said imaging lens. The optical element is configured as a phase-affecting, non-diffractive optical element defining a spatially low frequency phase transition. The optical element and the imaging lens define a predetermined pattern formed by spaced-apart substantially optically transparent features of different optical properties. Position of at least one phase transition region of the optical element within the imaging lens plane is determined by at least a dimension of said affective aperture.Type: GrantFiled: February 16, 2007Date of Patent: April 29, 2008Assignee: Xceed Imaging Ltd.Inventor: Zeev Zalevsky
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Patent number: 7345754Abstract: Fourier filters and wafer inspection systems are provided. One embodiment relates to a one-dimensional Fourier filter configured to be included in a bright field inspection system such that the bright field inspection system can be used for broadband dark field inspection of a wafer. The Fourier filter includes an asymmetric illumination aperture configured to be positioned in an illumination path of the inspection system. The Fourier filter also includes an asymmetric imaging aperture complementary to the illumination aperture. The imaging aperture is configured to be positioned in a light collection path of the inspection system such that the imaging aperture blocks light reflected and diffracted from structures on the wafer and allows light scattered from defects on the wafer to pass through the imaging aperture.Type: GrantFiled: September 16, 2005Date of Patent: March 18, 2008Assignee: KLA-Tencor Technologies Corp.Inventors: Guoheng Zhao, Mehdi Vaez-Iravani, Andrew V. Hill, Avijit K. Ray-Chaudhuri
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Patent number: 7330659Abstract: A wavelength filter, for filtering a WDM signal, comprises a demultiplexer, a multiplexer, and a control array connecting the demultiplexer and the multiplexer, where the demultiplexer and the multiplexer have a free spectral range (FSR) smaller than their wavelength channel span.Type: GrantFiled: March 2, 2001Date of Patent: February 12, 2008Assignee: Lucent Technologies Inc.Inventor: Christopher Richard Doerr
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Patent number: 7330657Abstract: An apparatus and method for demultiplexing multiple wavelengths of light. In one embodiment, an optical signal having a plurality of wavelengths is provided to an optical-to-electrical (OE) circuit configured to convert optical signals into electrical signals. The optical signal may include a plurality of wavelengths. The OE circuit converts the optical signal into a first electrical signal. The first electrical signal is received by a demodulating circuit, which also receives a demodulating signal. The demodulating circuit combines both the first electrical signal and the demodulating signal in order to produce a second electrical signal. Both the second electrical signal and the demodulating signal correspond to one of the wavelengths in the optical signal.Type: GrantFiled: April 1, 2004Date of Patent: February 12, 2008Assignee: Bookham Technology PLCInventor: Andrew C. Davidson
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Patent number: 7237940Abstract: A light guide plate (30) has a light incident surface (305) for receiving light, a light emitting surface (301) for emitting light, a bottom surface (303) opposite to the light emitting surface, and side surfaces (307, 309, 311). A subwavelength grating (302) is formed on the light incident surface for diffracting the light. The subwavelength grating is a zeroth-order grating which covers a wide wavelength band and diffracts the light into zeroth-order waves. So that the light guide plate has a high light utilization efficiency and yields high uniformity of outgoing light.Type: GrantFiled: December 23, 2004Date of Patent: July 3, 2007Assignee: Hon Hai Precision Industry Co. Ltd.Inventors: Tai-Cherng Yu, Charles Leu, Ga-Lane Chen
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Patent number: 7230603Abstract: An illumination device and display device using it display motion pictures without a blur and make a light utilizing efficiency of a backlight improved. An illumination device having a light pipe of a substantially parallel flat-form sheet, whose one surface is an outgoing light surface and a light source unit is placed at one side and both side edges, is equipped with a light axis of lights after having entered the light pipe from the light source unit being unparallel to the outgoing light surface of the light pipe, and a reflection body unit consisting of plural unit reflection bodies divided into m in a vertical direction of the light source unit at an opposite side surface of the outgoing light surface of the light pipe, wherein the reflection body unit can contact and separate from the opposite side surface the outgoing light surface of the light pipe for every unit reflection bodies.Type: GrantFiled: October 29, 2003Date of Patent: June 12, 2007Assignee: Hitachi, Ltd.Inventors: Tsunenori Yamamoto, Ikuo Hiyama, Akitoyo Konno, Osamu Ito
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Patent number: 7227687Abstract: One embodiment relates to a spatial light modulator (SLM) for modulating light incident thereon. The SLM includes a plurality of pixels, each pixel including a plurality of phase shift elements. The SLM also includes a transform filter adapted to control the imaging system to resolve each pixel but not each phase shift element in each pixel. The plurality of pixels are controlled to independently modulate phase and magnitude of light reflected therefrom. Other embodiments are also disclosed.Type: GrantFiled: June 22, 2005Date of Patent: June 5, 2007Assignee: Silicon Light Machines CorporationInventors: Jahja I. Trisnadi, Alexander P. Payne, Clinton B. Carlisle
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Patent number: 7221515Abstract: An optical diffraction element (1) comprises a diffraction layer (4) which is divided into diffraction strips (6) alternating with intermediate strips (8). The diffraction strips comprise nano-elements (10) which are aligned in one direction and absorb radiation (b) which is linearly polarized in this direction. The diffraction element may be a linear or two-dimensional grating (1) or a Fresnel lens (160). The polarization-sensitive grating can be used in optical systems in which only radiation with a specific polarization direction should be diffracted, or in an optical record carrier to allow reading of an information structure with high spatial frequencies.Type: GrantFiled: July 5, 2004Date of Patent: May 22, 2007Assignee: Koninklijke Philips Electronics N.V.Inventors: Ralph Kurt, Gert Wim 'T Hooft, Coen Theodorus Hubertus Fransiscus Liedenbaum, Robert Frans Maria Hendriks
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Patent number: 7215302Abstract: Even if a divided wavelength plate filter is mounted, it is possible to reliably display a three-dimensional image or perform a displaying operation on from one screen to a plurality of screens. In a display device, the relative positions of an image display section and a divided wavelength plate filter for rotating polarized light from image information at a first segment in a direction that is different from the direction of polarized light from image information at a second segment can be adjusted. At the time of positional adjustment, the display device displays a position adjustment pattern (112) having colors, figures, characters, symbols, diagrams, or designs, or combinations thereof which differ from each other depending on the segment.Type: GrantFiled: June 5, 2002Date of Patent: May 8, 2007Assignee: Sony CorporationInventors: Seiji Satoh, Hidehiko Sekizawa
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Patent number: 7106510Abstract: The present invention provides improved Wavefront Coding imaging apparatus and methods composed of optics, a detector, and processing of the detected image. The optics are constructed and arranged to have the characteristic that the transverse ray intercept curves form substantially straight, sloped lines. The wavefront coding corrects for known or unknown amounts of “misfocus-like” aberrations by altering the optical transfer function of the imaging apparatus in such a way that the altered optical transfer function is substantially insensitive to aberrations. Post processing then removes the effect of the coding, except for the invariance with regard to aberrations, thereby producing clear images.Type: GrantFiled: July 29, 2005Date of Patent: September 12, 2006Assignee: The Regents of the University of ColoradoInventor: Edward Raymond Dowski, Jr.
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Patent number: 7061693Abstract: An imaging arrangement and method for extended the depth of focus are provided. The imaging arrangement comprises an imaging lens having a certain affective aperture, and an optical element associated with said imaging lens. The optical element is configured as a phase-affecting, non-diffractive optical element defining a spatially low frequency phase transition. The optical element and the imaging lens define a predetermined pattern formed by spaced-apart substantially optically transparent features of different optical properties. Position of at least one phase transition region of the optical element within the imaging lens plane is determined by at least a dimension of said affective aperture.Type: GrantFiled: October 28, 2004Date of Patent: June 13, 2006Assignee: Xceed Imaging Ltd.Inventor: Zeev Zalevsky
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Patent number: 7057786Abstract: A grating coupled surface plasmon resonance optical modulator is disclosed. A electro-optic polymer dielectric is deposited on the metallic surface of a diffraction grating to provide a metal/dielectric interface. A surface plasmon will propagate at the metal/dielectric interface in a resonant condition, e.g., when the metal surface is illuminated by transverse magnetic (TM) polarized light of the appropriate wavelength, angle of incidence and phase velocity. In the present invention, phase velocity is controlled by the diffraction grating. A transparent electrode deposited on the electro-optic layer allows an electrical potential to be applied across the electro-optic polymer. The applied electrical potential (voltage) changes the index of refraction of the electro-optic polymer, thereby disrupting the resonant condition to produce an optically detectable change in reflectance of incident light from the metal layer.Type: GrantFiled: May 10, 2004Date of Patent: June 6, 2006Assignee: Ciencia, Inc.Inventors: Ray Sawin, Salvador M. Fernández
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Patent number: 7050235Abstract: A diffractive optical filter having a fractional level density s[j] and a transfer function C[m] that is an approximation to a desired Hermitian, passive transfer function B[m] is provided. The fractional level density s[j] is obtained by Fourier (or inverse Fourier) transforming B[m] to obtain t[j], calculating u[j]=t[j]?min(t[j]), calculating v[j]=u[j]/D where D is the sum of u[j] over j, and setting s[j] substantially equal to v[j]. A 2-D tiltable mirror array can be used to provide a 1024 tap optical filter having 10-bit tap resolution. Applications of the invention include laser tuning elements, spectroscopy and wavelength-division multiplexing, switching, and/or filtering.Type: GrantFiled: February 22, 2005Date of Patent: May 23, 2006Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Ruslan Belikov, Olav Solgaard
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Patent number: 7012749Abstract: A method of performing a DFT (discrete Fourier transform) or a DFT derived transform on data, comprising: providing spatially modulated light having spatial coherence, said spatially modulated light representing the data to be transformed; Fourier transforming said spatially modulated light, using an at least one optical element; and compensating for at least one of a scaling effect and a dispersion effect of said at least one optical element, using an at least one dispersive optical element.Type: GrantFiled: May 19, 2000Date of Patent: March 14, 2006Assignee: Lenslet Ltd.Inventors: David Mendlovic, Efraim Goldenberg, Naim Konforti, Zeev Zalevsky, Aviram Sariel
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Patent number: 7006215Abstract: A method and apparatus to illuminate a target. The apparatus can comprise a first lens configured to receive light from the light source, a diffractive optical element configured to receive the light from the first lens and to regulate the light into regulated light, and second lens configured to receive the regulated light and to direct the regulated light onto a selected area of the target.Type: GrantFiled: May 4, 2004Date of Patent: February 28, 2006Assignee: Applera Corporation Applied Biosystems GroupInventors: Louis B. Hoff, Mark F. Oldham
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Patent number: 6975786Abstract: An optical switch uses two ferroelectric liquid crystal spatial light modulators (10, 11) with an interconnect region in between. The switch uses bulk lenses (2, 8) to focus light from an input fibre array (1) to a first spatial light modulator (10), and from the second spatial light modulator (11) to an output array (9). Each spatial light modulator displays a respective hologram selected from a previously calculated set, to cause a desired switching of light from the input fibre array to the output array.Type: GrantFiled: October 4, 2000Date of Patent: December 13, 2005Assignee: Thomas Swan & Co. Ltd.Inventors: Steven Warr, Kim Leong Tan, William Crossland, Ilias Manolis, Maura Redmond, Timothy Wilkinson, Melanie Holmes, Brian Robertson
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Patent number: 6972905Abstract: Fractional Fourier transform properties of lenses or other optical environments are applied to one or more positive-definite optical transfer functions at locations outside the Fourier plane to realize or closely approximate arbitrary non-positive-definite transfer functions varying in both amplitude and phase. Controllable filter elements can be employed to create controllable optical processors which may be used for image filtering and optical computations using complex-valued arithmetic for monochromatic, color, and wide-spectrum optical signals. Applications include integrated optics, optical computing systems, particle beam systems, radiation accelerators, astronomical observation systems, and controllable lens systems.Type: GrantFiled: September 4, 2003Date of Patent: December 6, 2005Inventor: Lester F. Ludwig
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Patent number: 6961456Abstract: A method and apparatus is disclosed for reading and decoding information extracted from a form. In the system of the present invention, packages are randomly placed on a conveyor belt, with their labels facing a two-camera subassembly. As the conveyor belt moves, the two-camera subassembly continuously takes images of the belt underneath the overhead camera. The design of the camera permits it to take a high resolution image of a non-singulated, unjustified package flow. A digital image of the packages within the field of view of the camera is then transferred to the processing system for analysis. The processing system identifies individual packages in the image, extracts them and then analyzes the information written on the package labels. The analysis process utilizes conventional Optical Character Recognition (OCR) and Intelligent Character Recognition (ICR) techniques to evaluate the information written on the package label.Type: GrantFiled: March 2, 2004Date of Patent: November 1, 2005Inventors: Brett Bracewell Bonner, Ole-Petter Skaaksrud, Andris Jankevics
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Patent number: 6911637Abstract: Systems for optical wavefront sensing and control based on a phase contrast Fourier domain filtering technique. Optically or electronically controlled phase spatial light modulators (SLM) are used as the Fourier domain filter. A direct adaptive-optic feedback system using the optical wavefront sensing systems. A differential Zernike filter is also disclosed.Type: GrantFiled: May 23, 2002Date of Patent: June 28, 2005Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Mikhail A. Vorontsov, Eric W. Justh, Leonid I. Beresnev, Perinkulam Krishnaprasad, Jennifer C. Ricklin
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Patent number: 6907124Abstract: The invention relates to securing of information utilising optical imaging technologies and more specifically to phase encryption and decryption of images. An image is encrypted into a mask having a plurality of mask resolution elements (Xm, Ym) by encoding the image using e.g. a phase mask with an encoded phase value ? (Xm, Ym) and an encoded amplitude value a (Xm, Ym), and by further encrypting the mask (using e.g. a spatial light modulator) by addition of an encrypting phase value ?c (Xm, Ym) to the encoded phase value ? (Xm, Ym) and by multiplication of an encrypting amplitude value ac (Xm, Ym) with the encoded phase value a (Xm, Ym).Type: GrantFiled: June 16, 1999Date of Patent: June 14, 2005Assignee: Forskningscenter RisoInventor: Jesper Glũckstad
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Patent number: 6894748Abstract: A bump structure of a scattering reflective board and a method for manufacturing the bump structure. Multiple strip-shaped shielding sections are arranged on an optical mask at intervals. Multiple irregularly arranged circular holes are distributed in the respective strip-shaped shielding sections. Multiple irregularly arranged circular shielding sections are distributed in spacing sections between the adjacent strip-shaped shielding sections. Multiple irregularly arranged arch notches and arch shielding sections are distributed on the edges of the strip-shaped shielding sections. After exposed and developed, multiple scattered and irregularly arranged bumps are formed on the photosensitive material layer laid on the substrate. Then a reflective film is laid on the substrate and the bumps to form the reflective board.Type: GrantFiled: June 2, 2003Date of Patent: May 17, 2005Assignee: Wintek CorporationInventor: Yi Fan Chen
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Patent number: 6844947Abstract: A technique for processing optical input signals to produce optical output signals using only a single hologram for a plurality of circularly shifted code words used to encode the input signals. A spatial light modulator coupled to the each of the optical input signals encodes a corresponding one of the input optical signals, and the optical signals are linear combined for further processing. A matched filter composed of the single hologram receives the linear combination, and a two-dimensional microlens arrangement coupled to the matched filter emits each of the optical output signals from a corresponding microlens in the arrangement. Switching is engendered by controlling each spatial light modulator to thereby direct each input signal to the desired one of the microlens in the arrangement.Type: GrantFiled: January 2, 2003Date of Patent: January 18, 2005Inventors: Jawad Ahmed Salehi, Mohammad Abtahi
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Patent number: 6842285Abstract: The present invention provides a method and a system for generating a phase-modulated wave front. According to the present invention, the spatial phase-modulation is not performed on the different parts of the wave front individually as in known POSLMs. Rather, the spatial phase-modulation of the present invention is performed by generating an amplitude modulation in the wave front, Fourier or Fresnel transforming the amplitude modulated wave front, filtering Fourier or Fresnel components of the Fourier or Fresnel distribution with a spatial filter such as a phase contrast filter, and regenerating the wave front whereby the initial amplitude modulation has transformed into a phase-modulation.Type: GrantFiled: December 19, 2001Date of Patent: January 11, 2005Assignee: Riso National LaboratoryInventor: Jesper Glückstad
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Patent number: 6832003Abstract: A system and method for reading the information stored in holograms and other diffractive objects. The information is read by analyzing the diffraction pattern produced when a laser beam is focused onto a small spot on the object and scanned across the object.Type: GrantFiled: February 14, 2003Date of Patent: December 14, 2004Inventor: Stephen P. McGrew
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Patent number: 6762882Abstract: An imaging system is disclosed that includes an illumination source, a modulator and a variable Fourier diaphragm. The illumination source produces a first illumination field having a first frequency and a second illumination field having a second frequency. The modulator receives the first illumination field and the second illumination field, and produces a first modulated illumination field and a second modulated illumination fields. The variable Fourier diaphragm selectively passes one of the first modulated illumination field and the second modulated illumination field.Type: GrantFiled: November 14, 2002Date of Patent: July 13, 2004Assignee: Agfa COrporationInventors: Volker Melzer, Tobias Damm, Peter Mueller, Ralph Thoma
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Patent number: 6747781Abstract: A method of reducing speckle includes dividing a laser illuminated area into phase cells, subdividing the phase cells into cell partitions, and applying a temporal phase variation to the cell partitions within an integration time of an intensity detector viewing the laser illuminated area. An apparatus for reducing speckle includes illumination optics, a diffuser, and projection optics. The illumination optics couple a laser illumination to the diffuser, which is located in a first image plane. The diffuser divides the laser illumination into the phase cells and subdivides the phase cells into the cell partitions. The diffuser also applies the temporal phase variation to the cell partitions. The projection optics project an image of the first image plane onto a diffuse surface. A display apparatus adds a light modulator to the apparatus for reducing speckle and places the light modulator in a third image plane located between a laser source and the diffuser.Type: GrantFiled: July 2, 2001Date of Patent: June 8, 2004Assignee: Silicon Light Machines, Inc.Inventor: Jahja I. Trisnadi
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Patent number: 6744502Abstract: A method and apparatus to illuminate a target. The apparatus can comprise a first lens configured to receive light from the light source, a diffractive optical element configured to receive the light from the first lens and to regulate the light into regulated light, and second lens configured to receive the regulated light and to direct the regulated light to a selected area of the target.Type: GrantFiled: September 28, 2001Date of Patent: June 1, 2004Assignee: PE Corporation (NY)Inventors: Louis B. Hoff, Mark F. Oldham
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Publication number: 20040075901Abstract: An optical system for reforming a laser beam with azimuthal polarization having X and Y components into a beam with linear polarization has a multiplicity of optical elements, one of which has a mirror having an absorbing thin film reflective coating to remove the Y-component of the azimuthal beam polarization, thereby reflecting only the X or linear component as a linearly polarized beam. The absorbing thin film reflective coating is comprised of a plurality of layers alternately having high and low indices of refraction. The optical elements include a spatial filter and the beam is passed through the spatial filter to adjust the beam quality. At least one other optical element is collimating and the beam with adjusted beam quality is transmitted to the collimating element to effect its collimation. The collimated linearly polarized laser beam may thereafter be passed through a phase shifter to convert the polarization of the laser beam from linear to circular.Type: ApplicationFiled: October 21, 2002Publication date: April 22, 2004Inventors: Jochen Deile, Joachim Schulz
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Publication number: 20040067422Abstract: A photomask for use in photolithography has substrate, a main pattern at one side of the substrate, and a transparency-adjusting layer at the other side of the substrate. The transparency-adjusting layer has a characteristic that allows it to change the intensity of the illumination incident on the main pattern during the exposure process accordingly. In manufacturing the photomask, a first exposure process is carried out on a wafer using just the substrate and main pattern. The critical dimensions of elements of the pattern formed on the wafer as a result of the first exposure process are measured. Differences between these critical dimensions and a reference critical dimension are then used in designing a layout of the transparency-adjusting layer in which the characteristic of the layer is varied to compensate for such differences.Type: ApplicationFiled: July 22, 2003Publication date: April 8, 2004Inventors: Jong-Rak Park, Seong-Woon Choi, Gi-Sung Yeo, Sung-Hoon Jang
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Publication number: 20040057112Abstract: Fractional Fourier transform properties of lenses or other optical environments are applied to one or more positive-definite optical transfer functions at locations outside the Fourier plane to realize or closely approximate arbitrary non-positive-definite transfer functions varying in both amplitude and phase. Controllable filter elements can be employed to create controllable optical processors which may be used for image filtering and optical computations using complex-valued arithmetic for monochromatic, color, and wide-spectrum optical signals. Applications include integrated optics, optical computing systems, particle beam systems, radiation accelerators, astronomical observation systems, and controllable lens systems.Type: ApplicationFiled: September 4, 2003Publication date: March 25, 2004Inventor: Lester F. Ludwig
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Patent number: 6678411Abstract: An optical image characterizer 10 detects light energy as discrete angular orientations of a slit in a rotating spatial filter positioned at the focal plane of a Fourier transform lens, where a Fourier transform pattern of spatial frequencies of an image are formed. Detection of light energy with a small array (e.g., 16×16) photodetector is enhanced by splitting the beam containing the filtered light energy pattern and projecting it onto two photodetector arrays in offset, virtual juxtaposed relation to each other. Detected light intensities I at discrete angular orientations R are stored in RIXel data arrays with or without searchable flags X, such as distortion factors.Type: GrantFiled: March 27, 2000Date of Patent: January 13, 2004Assignee: Look Dynamics, Inc.Inventor: Rikk Crill
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Patent number: 6671452Abstract: An optical device for collecting light and selectively outputting or concentrating the light. A layer has an optical index of referaction n1, and top, bottom and side surfaces defining an angel of inclination &phgr;. A back surface spans the top, bottom and side surface. A first layer is coupled to the bottom surface of the layer and has an index of refraction n2. The first layer index n2 causes light input through the back surface of the layer to be preferentially output into the first layer. A second layer is coupled to the bottom of the first layer and selectively causes output of light into ambient. Additional layers, such as alight polarization layer, a polarization converting layer and a post LCD diffuser layer can be used to make preferential use of polarized light of diffuse light having passed through the LCD layer to enhance viewing of the output light.Type: GrantFiled: November 27, 2001Date of Patent: December 30, 2003Assignee: 3M Innovative Properties CompanyInventors: Roland Winston, Robert L. Holman, Benjamin A. Jacobson, Robert M. Emmons, Philip Gleckman
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Patent number: 6657786Abstract: The present invention relates to a method for synthesizing supergratings using Fourier analysis. The method divides the synthesis process into two stages: synthesis of an “analog” grating profile, followed by a quantization step. The method provides a generalized procedure for analog synthesis by drawing on the Fourier approximation and on finite-impulse-response (FIR) filter design theory, while it interprets the simple threshold quantization as a “zeroth order” Delta-Sigma Modulator, which it improves.Type: GrantFiled: May 13, 2002Date of Patent: December 2, 2003Assignee: Digital LightCircuits, Inc.Inventors: Daniel Levner, Martin F. Fay, Jingming Xu
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Image processing utilizing non-positive-definite transfer functions via fractional fourier transform
Patent number: 6650476Abstract: Fractional Fourier transform properties of lenses or other elements or optical environments are used to introduce one or more positive-definite optical transfer functions outside the Fourier plane so as to realize or closely approximate arbitrary non-positive-definite transfer functions. Designs can be straightforwardly obtained by methods of approximation. The invention provides for single and multiple channel controllable optical processors which may be used for image or other types of computation, including computation with complex-valued arithmetic, visual color, and wide-spectrum optical signals. The invention also provides for synthesis of Fractional Fourier transforms, extensions to non-Hermite basis functions, phase-shifting filter elements and non-quadratic graded-index materials (which do not naturally invoke the Fractional Fourier transform operation).Type: GrantFiled: February 25, 2000Date of Patent: November 18, 2003Inventor: Lester Frank Ludwig -
Patent number: 6636293Abstract: A method and apparatus for transferring a fine pattern (12) on a mask (11) onto a substrate (17) by a projection exposure apparatus including an illumination optical system (1-10) for irradiating an illuminating light on the mask (11), and a projection optical system (13) for projecting an image of the fine pattern (12) on the illuminated mask onto the substrate (17).Type: GrantFiled: August 19, 1999Date of Patent: October 21, 2003Assignee: Nikon CorporationInventor: Naomasa Shiraishi
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Patent number: 6631017Abstract: A matched amplification correlator transforms input images projecting a real time hologram upon a holographic storage device and a spatial light modulator, optically coupled to the storage device, modulates the hologram with a correlation filter, and the modulated signal is Fourier transformed to produce an output correlation signal. Alternatively, Fourier transforms of beams bearing the signals to be correlated are projected upon a beam controlled semi-conductor absorption modulator for selectively switching the Fourier transform of the noisy cluttered image through the device, and a spatial light modulator, modulates the hologram with a correlation filter, and the transform produces an output correlation signal. These compact adaptive, noise robust correlators can be made as small as one cubic centimeter. In a correlation system of exemplary figure one, nearly one hundred million correlations per second (0.1 Ghz) are possible. Front end components of the correlators can be used to clean noisy images.Type: GrantFiled: October 9, 2001Date of Patent: October 7, 2003Inventor: Jed Khoury
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Patent number: 6602596Abstract: There is provided a light diffusion sheet comprising a light diffusion layer formed on a transparent substrate and containing a binder resin and resin particles that impart an uneven surface, wherein the uneven surface of the light diffusion layer exhibits an arithmetical mean deviation of 2.0 &mgr;m or more in three-dimensional surface roughness measurement and/or ten point height of irregularities of 10.0 &mgr;m or more in three-dimensional surface roughness measurement. This light diffusion sheet is high luminance in the front direction, is excellent in light-diffusing property, and is resistant to damage.Type: GrantFiled: May 15, 2001Date of Patent: August 5, 2003Assignee: Kimoto Co., Ltd.Inventors: Yoshihisa Kimura, Kenji Fukui, Junji Ichinokawa, Teruo Ohnuma
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Patent number: 6577429Abstract: A display apparatus includes a laser light source for emitting a light beam having a coherence length; a beam expander for expanding the light beam; a spatial light modulator; beam shaping optics for shaping the expanded laser beam to provide uniform illumination of the spatial light modulator, the beam shaping optics including a fly's eye integrator having an array of lenslets; a diffuser located in the light beam between the laser light source and the beam shaping optics; an electrically controllable de-speckling modulator for modifying the temporal and spatial phase of the light beam; and a projection lens for producing an image of the spatial light modulator on a distant screen.Type: GrantFiled: January 15, 2002Date of Patent: June 10, 2003Assignee: Eastman Kodak CompanyInventors: Andrew F. Kurtz, Brian E. Kruschwitz, Sujatha Ramanujan
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Publication number: 20030099423Abstract: An integrated dispersion compensator planar lightwave circuit (PLC). The PLC includes an input for receiving a fiber optic signal. The input couples the signal to a Fourier filter. The filter is configured to add a phase compensation to the signal to correct a chromatic dispersion of the signal. An output is coupled to transmit the dispersion compensated signal from the Fourier filter to other components on the PLC or to other external devices. The Fourier filter can be implemented using a tap delay filter. The tap delay filter can be implemented by using a plurality of delay lines for implementing the phase compensation for the signal. The delay lines can be implemented using Mach Zehnder couplers, wherein the Mach Zehnder couplers are configured to distribute power from signal between the delay lines and to recombine the power from the delay lines to generate the dispersion compensated signal. A plurality of thermal optic phase shifters can be coupled to the delay lines to generate the phase compensation.Type: ApplicationFiled: November 29, 2001Publication date: May 29, 2003Inventors: Koorosh Aflatooni, Anthony J. Ticknor
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Patent number: 6570708Abstract: An optical coherent processor or correlator for processing an input image produced by an imaging device illuminated by a coherent light source utilizes an optical key for preventing unauthorized use of the processor. The principle underlying processing apparatus and method according to the invention uses an optical lock in combination with an encoded software key superimposed on a filter image. The optical lock, which is preferably in hardware form, consists of a first optical mask implementing a locking mask function that is preferably complex (phase and/or amplitude), which first optical mask is included in the optical path of the processor. The mask is fixed during assembly of the processor or correlator and a unique pattern is encoded thereon. The software key consists of a pattern defined by a key mask function that is displayed preferably using a spatial light modulator as part of a second optical mask included on the processor optical path.Type: GrantFiled: September 18, 2000Date of Patent: May 27, 2003Assignee: Institut National d'OptiqueInventors: Alain Bergeron, Michel Doucet, Donald Prévost
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Patent number: 6555955Abstract: The present invention provides to a front panel for a display in which the light transmittance of the front panel at a wavelength of 450 nm is higher than the light transmittance at a wavelength of 525 nm and the light transmittance at the wavelength of 525 nm is higher than the light transmittance at a wavelength of 630 nm. The front panel for a display of the present invention improves image contrast and color reproducibility of the display, when it is installed at the front side of a projection television receiver, a liquid crystal display, a plasma display, or the like.Type: GrantFiled: July 26, 1999Date of Patent: April 29, 2003Assignee: Sumitomo Chemical Company, LimitedInventor: Satoshi Honda
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Patent number: 6525879Abstract: An optical filtering apparatus and method, wherein at least one polarizer is located in the path of radiation passing through a birefringent medium. The invention can be used to process complementary bands of spatial frequency spectra. The invention can be practiced using a polarizing beam splitter. The invention can also be practiced using an optical storage layer forming part of the birefringent medium.Type: GrantFiled: May 25, 2000Date of Patent: February 25, 2003Assignee: Fuji Xerox Co., Ltd.Inventors: Katsunori Kawano, Jiro Minabe, Takehiko Niitsu, Tsutomu Ishii, Yasunari Nishikata, Kazuo Baba
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Publication number: 20020159152Abstract: This invention relates to an apparatus for optical beam shaping and diffusing, a method for making the apparatus, and a method for using the apparatus. The apparatus comprises a crystalline material object shaped to fit within an optical train and with a pattern of surface texture along an optical path. Surface removal processes are applied to a portion of a surface of an object made of a crystalline material to form a surface texture pattern at that portion of the surface of the object. The surface texture pattern depends upon: (1) the identity of the crystalline material and (2) the orientation of crystal lattice axes within the object with respect to the portion of the surface of the object where the pattern of surface texture is to be formed. Processes for making the apparatus include, but are not limited to, mechanical grinding, ablating, chemical etching, plasma etching, ion milling, and combinations thereof.Type: ApplicationFiled: April 25, 2002Publication date: October 31, 2002Applicant: ASML US, Inc.Inventor: Matthew E. Hansen
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Publication number: 20020154410Abstract: The present invention relates to a method for synthesizing supergratings using Fourier analysis. The method divides the synthesis process into two stages: synthesis of an “analog” grating profile, followed by a quantization step. The method provides a generalized procedure for analog synthesis by drawing on the Fourier approximation and on finite-impulse-response (FIR) filter design theory, while it interprets the simple threshold quantization as a “zeroth order” Delta-Sigma Modulator, which it improves.Type: ApplicationFiled: May 13, 2002Publication date: October 24, 2002Inventors: Daniel Levner, Martin F. Fay, Jingming Xu
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Publication number: 20020122254Abstract: The present invention provides a method and a system for generating a phase-modulated wave front. According to the present invention, the spatial phase-modulation is not performed on the different parts of the wave front individually as in known POSLMs. Rather, the spatial phase-modulation of the present invention is performed by generating an amplitude modulation in the wave front, Fourier or Fresnel transforming the amplitude modulated wave front, filtering Fourier or Fresnel components of the Fourier or Fresnel distribution with a spatial filter such as a phase contrast filter, and regenerating the wave front whereby the initial amplitude modulation has transformed into a phase-modulation.Type: ApplicationFiled: December 19, 2001Publication date: September 5, 2002Inventor: Jesper Gluckstad
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Publication number: 20020114075Abstract: The invention concerns a device for optically transforming at least a radiation beam having a width extending in the plane X-Y. The device including optical elements provided with optically active interfaces, arrange in the radiation path. So as to obtain a more homogeneous intensity distribution in the output radiation beam and minimize internal losses, the invention includes at least one optical element in the form of a continuous angular transformation element including an optical interface having, along the x axis, an inclination continuously varying in the radiation direction, relative to the Y axis. The invention further concerns a method for continuously transforming a beam width extending in the X-Y plane, at least in the direction X, with defined divergence distribution.Type: ApplicationFiled: April 5, 2002Publication date: August 22, 2002Inventors: Vitalij Lissotschenko, Alexei Mikhailov
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Patent number: 6424449Abstract: A collimator optical system collimates light from the coherent light source. A reflection type spatial light modulator returns collimated light from the collimator optical system to the collimator optical system. A Fourier transformation optical system Fourier-transforms light from the reflection type spatial light modulator and shares at least partial optical system with the collimator optical system. An emission light from another coherent light source passes through an incident light path composed of another collimator optical system, spatial modulator and polarized beam splitter in this order and reaches the reflection type spatial light modulator. Then, a reflection light from the reflection type spatial light modulator passes through a reflection light path which is reverse to the incident light path and reaches a polarized beam splitter. That is, the incident light path and reflection light path are split by the polarized beam splitter.Type: GrantFiled: April 19, 2000Date of Patent: July 23, 2002Assignee: Olympus Optical Co., Ltd.Inventor: Mitsuru Namiki
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Patent number: 6421178Abstract: The invention concerns a device for optically transforming at least a radiation beam having a width extending in the plane X-Y. The device including optical elements provided with optically active interfaces, arrange in the radiation path. So as to obtain a more homogeneous intensity distribution in the output radiation beam and minimize internal losses, the invention includes at least one optical element in the form of a continuous angular transformation element including an optical interface having, along the x axis, an inclination continuously varying in the radiation direction, relative to the Y axis. The invention further concerns a method for continuously transforming a beam width extending in the X-Y plane, at least in the direction X, with defined divergence distribution.Type: GrantFiled: September 8, 2000Date of Patent: July 16, 2002Assignees: Joachim HentzeInventors: Vitalij Lissotschenko, Alexei Mikhailov