By Reflection Patents (Class 359/263)
  • Patent number: 6384979
    Abstract: A color image display having a spatially uniform distribution of at least two different “types” of prism structure. The first type consists of a prism, a color filter associated with one of the prism's facets and two color absorbing control members, each of which can be biased away from or into optical contact with one of the prism's other two facets. The color filter has a first spectral absorption characteristic, and the control members have second and third spectral absorption characteristics respectively. The second type of prism structure consists of a second prism, a color filter associated with one of the second prism's facets and at least one color absorbing control member which can be biased away from or into optical contact with one of the second prism's other two facets. The second prism's color filter and control member have fourth and fifth spectral absorption characteristics respectively.
    Type: Grant
    Filed: November 30, 2000
    Date of Patent: May 7, 2002
    Assignee: The University of British Columbia
    Inventors: Lorne A. Whitehead, Michele Ann Mossman
  • Patent number: 6384953
    Abstract: Disclosed is an optical modulating device capable of use as a light-valve, display, optical filter or Fabry-Perot cavity, for example. The device lends itself to batch processing, and is compatible with monolithic integration with silicon, silicon-germanium, silicon-on-sapphire (SOS) or silicon-on-quartz (SOQ) advanced microelectronic technology (NMOS, PMOS and CMOS) for integrated control circuitry, electrical addressing, system interfacing, and the like. The device forgoes the complexities of liquid crystal constructions, and avoids the need to position and fix piezoelectric spacers within layers of the device. The invention includes first and second transparent layers that are disposed to oppose one another. Metallic layers are disposed upon the inwardly facing surfaces of the transparent layers and these are arranged to oppose each other. Spectral coupling layers are disposed upon the outwardly facing surfaces of the transparent layers opposite of the metallic layers.
    Type: Grant
    Filed: June 29, 2000
    Date of Patent: May 7, 2002
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Stephen D. Russell, Randy L. Shimabukuro
  • Publication number: 20020024711
    Abstract: An Interferometric Modulator (IMod) is a microelectromechanical device for modulating light using interference. The colors of these devices may be determined in a spatial fashion, and their inherent color shift may be compensated for using several optical compensation mechanisms. Brightness, addressing, and driving of IMods may be accomplished in a variety of ways with appropriate packaging, and peripheral electronics which can be attached and/or fabricated using one of many techniques. The devices may be used in both embedded and directly perceived applications, the latter providing multiple viewing modes as well as a multitude of product concepts ranging in size from microscopic to architectural in scope.
    Type: Application
    Filed: October 10, 2001
    Publication date: February 28, 2002
    Applicant: Iridigm Display Corporation, a Delaware corporation
    Inventor: Mark W. Miles
  • Publication number: 20010040717
    Abstract: A reflective display device includes a switching layer, placed between substrates, for switching between a transmissive state for allowing transmission of incident light and a scattering state for scattering the incident light, and a retro-reflector for reflecting an incident ray from the liquid crystal layer so that an outgoing ray of the reflected light is parallel to the incident ray. A pitch of smallest unit structures of the retro-reflector is set to be larger than 0 mm and not more than 5 mm. The retro-reflector is preferably in a form of a corner cube array and has light absorbing surface portions at borders of the smallest unit structures. With this reflective display device, brightness of white state and contrast ratio can be improved.
    Type: Application
    Filed: March 30, 2001
    Publication date: November 15, 2001
    Inventors: Kiyoshi Minoura, Shun Ueki, Masahiko Tomikawa, Teiyu Sako, Masayuki Okamoto, Seiichi Mitsui
  • Patent number: 6310713
    Abstract: An illumination system and display are disclosed that include a light for providing light, a polarizing beam splitter (PBS) having a first surface that receives the light from the backlight. The PBS passes a first polarization of the received light to a curved mirror located at a second PBS face, which second PBS face is opposite the first PBS face. The curvature of the mirror provides the optical power necessary for proper imaging, while limiting the reflecting area of the mirror provides an aperture stop that determines the numerical aperture of the optical system. The display also includes a quarter wave plate and a spatial light modulator (SLM). The quarter wave plate is located between the PBS and mirror and changes the first polarization of light, directed from the PBS to the mirror, to a second polarization which is reflected from the mirror back to the PBS.
    Type: Grant
    Filed: April 7, 1997
    Date of Patent: October 30, 2001
    Assignee: International Business Machines Corporation
    Inventors: Fuad Elias Doany, Rama Nand Singh
  • Patent number: 6304365
    Abstract: The invention provides an image display for viewing images in a preferred viewing direction. The display has parallel, macroscopically planar, structured surface, non-light absorptive light deflecting and reflecting portions which are longitudinally symmetrical in mutually perpendicular directions, both of which are perpendicular to the preferred viewing direction. A liquid containing a plurality of movable members contacts the light reflecting portion. A controller applies an electromagnetic force to selectively move the members into an evanescent wave region adjacent the light reflecting portion to frustrate TIR of light rays at selected points on the light reflecting portion. The structured surfaces on the light deflecting portion deflect light rays incident in the preferred viewing direction toward the light reflecting portion by imparting to the rays a directional component in the direction of longitudinal symmetry of the light reflecting portion.
    Type: Grant
    Filed: June 2, 2000
    Date of Patent: October 16, 2001
    Assignee: The University of British Columbia
    Inventor: Lorne A. Whitehead
  • Patent number: 6285487
    Abstract: A method and apparatus for modulating light, wherein a light source provides light of a certain wavelength to be modulated by a layer of superconducting material which forms part of a specifically configured plate assembly. The superconducting layer is placed in the optical path of the light source. Further the superconducting layer is switched between a partially transparent non-superconducting state and a substantially non-transparent superconducting state by a modulation circuit. The resulting optical pulses transmitted through the superconducting layer are converted from the original wavelength to a lower wavelength by a frequency converting device.
    Type: Grant
    Filed: August 10, 2000
    Date of Patent: September 4, 2001
    Assignee: TeraComm Research, Inc.
    Inventor: Kenneth A. Puzey
  • Patent number: 6278540
    Abstract: Efficient color filtering and beam steering by combining the total internal reflection and the electro-optic effect in a special way.
    Type: Grant
    Filed: March 26, 1999
    Date of Patent: August 21, 2001
    Assignee: California Institute of Technology
    Inventor: Yu Wang
  • Publication number: 20010004296
    Abstract: A transflective color display having apertures in reflective electrodes through which light from a backlight (9) passes in the transmissive mode. The switching behavior for both the reflective and the transmissive mode is made identical by introducing a retardation plate (11). The transmission efficiency is further increased by using only a monochrome green mode in transmission.
    Type: Application
    Filed: February 6, 2001
    Publication date: June 21, 2001
    Applicant: U.S. PHILIPS CORPORATION
    Inventors: Nicolass A.J.M. Van Aerle, Michael G. Pitt
  • Publication number: 20010003487
    Abstract: Light in the visible spectrum is modulated using an array of modulation elements, and control circuitry connected to the array for controlling each of the modulation elements independently, each of the modulation elements having a surface which is caused to exhibit a predetermined impedance characteristic to particular frequencies of light. The amplitude of light delivered by each of the modulation elements is controlled independently by pulse code modulation. Each modulation element has a deformable portion held under tensile stress, and the control circuitry controls the deformation of the deformable portion. Each deformable element has a deformation mechanism and an optical portion, the deformation mechanism and the optical portion independently imparting to the element respectively a controlled deformation characteristic and a controlled modulation characteristic. The deformable modulation element may be a non-metal.
    Type: Application
    Filed: August 20, 1999
    Publication date: June 14, 2001
    Inventor: MARK W. MILES
  • Patent number: 6169624
    Abstract: Micromachined grating modulators which exhibit achromatic behavior are described. One embodiment includes narrow and wide ribbons suspended above a substrate and alternatingly interleaved with each other. Narrow and wide reflective surfaces are formed on the narrow and wide ribbons. Compensating reflective surfaces are formed in the gaps between and beneath the ribbons. The width of the ribbons as well as the width of the gaps and the compensating reflecting surfaces are designed so that incident optical beam can be modulated or attenuated in an achromatic fashion.
    Type: Grant
    Filed: August 11, 1999
    Date of Patent: January 2, 2001
    Inventors: Asif A. Godil, David M. Bloom
  • Patent number: 6166846
    Abstract: A through silicon optical modulator alters a phase of a light beam which enters the back of a silicon die. The modulator can be formed as a PMOS transistor fabricated in an n-well, or can be an NMOS transistor having a negative gate to substrate voltage. By modulating the well voltage (or gate potential) the phase of a portion of the reflected light is altered. Two accumulation layers are selectively formed in the light path which is reflected from the transistor gate electrode. The phase change is detected to provide a signal from the integrated circuit having the through silicon optical modulator structure.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: December 26, 2000
    Assignee: Intel Corporaqtion
    Inventor: Timothy J. Maloney
  • Patent number: 6097456
    Abstract: A display system having a non-absorbing and reflective color filtering array and a reflector to improve light utilization efficiency. One implementation of the color filtering array uses a surface plasmon filter having two symmetric metal-dielectric interfaces coupled with each other to produce a transmission optical wave at a surface plasmon resonance wavelength at one interface from a p-polarized input beam on the other interface. Another implementation of the color filtering array uses a metal-film interference filter having two dielectric layers and three metallic films.
    Type: Grant
    Filed: August 12, 1998
    Date of Patent: August 1, 2000
    Assignee: California Institute of Technology
    Inventor: Yu Wang
  • Patent number: 6061166
    Abstract: A modulator for modulating an incident beam of light having a wavelength .lambda. including a base having a surface; an electrode formed over the surface of the base; a plurality of equally spaced apart deformable elements arranged over the electrode and being disposed parallel to each other and secured at opposite ends of each spaced apart deformable element and suspended above the base and having at least two spaced apart conductive and reflective portions and a central reflective portion electrically insulated from the two spaced apart conductive and reflective portions and disposed therebetween; a reflective layer disposed over the base between the spaced apart deformable elements; and applying a potential between the electrode and the spaced apart conductive and reflective portions so that the spaced apart conductive and reflective portions are movable between first and second positions which are substantially .lambda./4 apart.
    Type: Grant
    Filed: October 15, 1998
    Date of Patent: May 9, 2000
    Assignee: Eastman Kodak Company
    Inventors: Edward P. Furlani, Syamal K. Ghosh, Dilip K. Chatterjee
  • Patent number: 6028693
    Abstract: By applying a photonic signal to a microresonator that includes a photonic bandgap delay apparatus having a photonic band edge transmission resonance at the frequency of the photonic signal, the microresonator imparts a predetermined delay to the photonic signal. The photonic bandgap delay apparatus also preferably has a photonic band edge transmission resonance bandwidth which is at least as wide as the bandwidth of the photonic signal such that a uniform delay is imparted over the entire bandwidth of the photonic signal. The microresonator also includes a microresonator cavity, typically defined by a pair of switchable mirrors, within which the photonic bandgap delay apparatus is disposed. By requiring the photonic signal to oscillate within the microresonator cavity so as to pass through the photonic bandgap delay apparatus several times, the microresonator can controllably impart an adjustable delay to the photonic signal.
    Type: Grant
    Filed: January 14, 1998
    Date of Patent: February 22, 2000
    Assignees: University of Alabama in Huntsville, The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Richard Lynn Fork, Darryl Keith Jones, Andrew Scott Keys
  • Patent number: 5986796
    Abstract: Light in the visible spectrum is modulated using an array of modulation elements, and control circuitry connected to the array for controlling each of the modulation elements independently, each of the modulation elements having a surface which is caused to exhibit a predetermined impedance characteristic to particular frequencies of light. The amplitude of light delivered by each of the modulation elements is controlled independently by pulse code modulation. Each modulation element has a deformable portion held under tensile stress, and the control circuitry controls the deformation of the deformable portion. Each deformable element has a deformation mechanism and an optical portion, the deformation mechanism and the optical portion independently imparting to the element respectively a controlled deformation characteristic and a controlled modulation characteristic. The deformable modulation element may be a non-metal.
    Type: Grant
    Filed: November 5, 1996
    Date of Patent: November 16, 1999
    Assignee: Etalon Inc.
    Inventor: Mark W. Miles
  • Patent number: 5966234
    Abstract: An optical fiber compatible modulator device provides high-contrast levels switchable using modest applied voltages. As a two-port optical modulator, a normal light signal incident at a first port is deflected to a non-normal direction for passage through an absorption layer (e.g., a multiple-quantum well (MQW) layer), the absorption layer having an adsorption characteristic which changes as a function of a voltage applied across it. The non-normal direction light signal exiting the absorption layer is deflected to a normal light signal for output from a second port of the optical modulator. As a one-port optical modulator, a normal light signal received at a first port is deflected to a non-normal direction for passage through an absorption layer. A reflector reflects a non-normal direction light signal exiting the layer back through the layer to the deflector means and is output at the port of the optical modulator.
    Type: Grant
    Filed: June 24, 1997
    Date of Patent: October 12, 1999
    Assignee: Lucent Technologies Inc
    Inventors: Joseph Earl Ford, Anthony Lodovico Lentine, Ted Kirk Woodward
  • Patent number: 5959777
    Abstract: A variably reflective display device amenable to multiple pixel display applications. Each pixel has at least one element having a reflective state in which incident light undergoes total internal reflection, and having a non-reflective state in which total internal reflection is prevented. Such prevention is achieved by interfering with (scattering and/or absorbing) the evanescent wave adjacent the surface of the element. For example, a member can be positioned adjacent the element and deformed between first and second positions. In the first position a gap remains between the member and the element to allow the evanescent wave to behave normally. In the second position the member is in optical (but not atomic) contact with the element, such that the member interferes with the evanescent wave and thereby prevents total internal reflection. In one embodiment, each pixel is a grouping of retro-reflective elements, such as corner reflectors. An elastomeric material is provided adjacent each grouping.
    Type: Grant
    Filed: June 10, 1997
    Date of Patent: September 28, 1999
    Assignee: The University of British Columbia
    Inventor: Lorne A. Whitehead
  • Patent number: 5920418
    Abstract: The diffractive optical modulator of the invention includes: a plate having a portion functioning as a first electrode; a spacer layer formed on the plate; and a grating consisting of a plurality of beams having a portion functioning as a second electrode, both ends of the beams being supported on the spacer layer. In the diffractive optical modulator, by adjusting a voltage applied between the first electrode and the second electrode, a distance between the beams and the plate is varied, thereby controlling the diffraction efficiency. An insulating layer is further provided between the plate and the plurality of beams.
    Type: Grant
    Filed: June 20, 1995
    Date of Patent: July 6, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Teruhiro Shiono, Michihito Ueda, Tatsuo Ito, Kazuo Yokoyama, Shinichi Mizuguchi
  • Patent number: 5910855
    Abstract: A passive acousto-optic modulator for the modulation of a light beam as a function of a variation in air pressure comprising a beam splitter arranged relative to the beam so as to produce a signal beam and reference beam, the beam splitter ideally comprising a flat interface located between two optically transparent mediums such as the end of an optic fiber located within air, the interface being arranged relative to the light modulator such that when the light beam travels through the interface, some of the light beam is able to pass through the interface to form the signal beam, the rest of the light beam being reflected back off the interface to form the reflected reference beam; a light modulator which modulates the signal beam, the light modulator comprising an approximately flat optically reflective surface capable of movement, the reflective surface being located in a position which, at rest is a predetermined distance from the beam splitter and is approximately parallel to and facing the beam splitter
    Type: Grant
    Filed: September 3, 1997
    Date of Patent: June 8, 1999
    Assignee: The Secretary of State for Defense in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventor: Andrew James Thomas
  • Patent number: 5896005
    Abstract: A display device is disclosed including a plurality of pixels arranged in a predetermined configuration. Each pixel including a mirror element disposed over a flat surface. A light modulating material disposed over the mirror element for selectively modulating a predetermined wave length of light received from an external source by transitioning between a first and a second state. The light modulating material in the first state causes destructive interference in the predetermined wave length of light and in the second state causes constructive interference in the predetermined wave length of light.
    Type: Grant
    Filed: January 29, 1997
    Date of Patent: April 20, 1999
    Assignee: Copytele, Inc.
    Inventors: Michael Gurvitch, Maurice Halioua, Alexander Kastalsky, Sylvain Naar, Sergey Shokhor
  • Patent number: 5886807
    Abstract: A traveling-wave electro-optic modulator using reflected signals to achieve a one-time rephasing. For a given crystal length, the interaction length is effectively doubled and a 3-dB gain is automatically achieved compared to a conventional traveling-wave modulator.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: March 23, 1999
    Assignee: California Institute of Technology
    Inventor: Uri Cummings
  • Patent number: 5786925
    Abstract: A method for forming, and an arrangement for using arbitrary angle mirrors in substrates is disclosed. An erodible material, such as a photoresist, is applied to a substrate at a site and is exposed to radiation at that site which has a linear variation in energy at the surface of the erodible material. Due to this variation in exposure energy, a taper results in the erodible material after development. The tapered region is then etched in a manner which etches both the erodible layer and the underlying substrate. The taper in the erodible layer provides a varying attenuation during the etching process such that the taper of the erodible layer, or a multiple of it, is transferred to the substrate. In a first embodiment, a tapered reflective surface is formed in a substrate, which surface engages an optical signal and deflects it to an optical device or another surface.
    Type: Grant
    Filed: May 20, 1996
    Date of Patent: July 28, 1998
    Assignee: Lucent Technologies Inc.
    Inventors: Keith Wayne Goossen, James Albert Walker
  • Patent number: 5751466
    Abstract: A photonic signal is applied to a photonic bandgap structure having a photonic band edge transmission resonance at the frequency of the photonic signal and having a photonic band edge transmission resonance bandwidth which is at least as wide as the bandwidth of the photonic signal. When a photonic band edge transmission resonance is matched to the photonic signal which is being transmitted, a controllable delay is imparted to the photonic signal without significantly altering the photonic signal itself.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: May 12, 1998
    Assignee: University of Alabama at Huntsville
    Inventors: Jonathan P. Dowling, Michael Scalora, Mark J. Bloemer, Charles M. Bowden, Rachel J. Flynn, Richard L. Fork, Senter B. Reinhardt, Jr., Michael D. Tocci
  • Patent number: 5737113
    Abstract: An optical modulator includes a first diffraction grating for separating a light flux of a wide wavelength band into light fluxes of given wavelength bands. The optical modulator further includes an optical modulation element for modulating the separated light fluxes through corresponding picture elements, respectively, and outputting them. The optical modulator further includes a second diffraction grating for synthesizing the modulated light fluxes outputted from the optical modulation element, wherein the first diffraction grating, the optical modulation element and the second diffraction grating are integrally structured.
    Type: Grant
    Filed: August 1, 1996
    Date of Patent: April 7, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Junko Kuramochi, Michitaka Setani, Takehiko Nakai, Saburo Sugawara
  • Patent number: 5691836
    Abstract: An optically addressed spatial light modulator includes a reflective modulation element, a detector for detecting radiation, a micro-lens focusing a write beam on the detector and a read beam on the modulator element, and a circuit receiving a signal output from the detector generated in response to the write beam. The circuit alters the modulation element in accordance with the signal from the photodetector. The read beam is thus modulated in accordance with the amount of alteration of the modulation element. The read and write beams intercept the micro-lens at different angles and may have the same or differing wavelengths. Including multiple photodetectors on a single pixel allows use of a plurality of write beams. An array of the elements may be used to modulate a plurality of read beams.
    Type: Grant
    Filed: July 11, 1995
    Date of Patent: November 25, 1997
    Assignee: SY Technology, Inc.
    Inventor: Rodney L. Clark
  • Patent number: 5657148
    Abstract: A single-port, reflective, optical modulator with internal amplification. In one advantageous embodiment of the present invention, the single-port modulator includes a semiconductor waveguide amplifier with a high reflector at one end. The single-port geometry reduces the high packaging cost associated with two-port modulators, while the internal amplification compensates for splitting and coupling losses. The single-port optical modulator generally includes an input/output port for receiving a light input signal. A modulation region for modulating the light input signal in response to an electrical drive signal is included along with an amplification region for providing amplification of the light input signal. The modulation region and the amplification region include a waveguide for directing the light input signal.
    Type: Grant
    Filed: May 7, 1996
    Date of Patent: August 12, 1997
    Assignee: Lucent Technologies Inc.
    Inventors: Mark D. Feuer, Jay M. Wiesenfeld
  • Patent number: 5629801
    Abstract: A reflective/diffractive light valve system collects light from multiple dimensions around a single light source. From these multiple collection dimensions, the light is directed to impinge on the valve from multiple directions. When the valve is configured to be reflective, the light returns to the source. On the other hand, when the valve is configured to be diffractive, light from a first and third order diffraction are transmitted from the valve for each of the collection dimensions which greatly enhances the efficiency of the system.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: May 13, 1997
    Assignee: Silicon Light Machines
    Inventors: Bryan P. Staker, David M. Bloom, Bryan E. Loucks
  • Patent number: 5570139
    Abstract: A surface plasmon high efficiency HDTV projector employs voltage-induced color-selective absorption with surface plasmons at metal/liquid crystal interface. When a collimated p-polarized white light (9) is incident at metal (2) and liquid crystal (6) interface, surface plasmon resonance can be excited, certain frequencies of photons will be absorbed without reflection, and the reflected light shows the complementary color. This resonance frequency depends on the dielectric constant of both the metal film and the liquid crystal. If a voltage (8) is applied on the liquid crystal (6) to change its dielectric constant, then the absorption spectrum can be controlled by this voltage. When the p-polarized white light is reflected three times at three interfaces which are set a surface plasmon resonance at blue, green and red respectively, any color can be generated by switching these resonances.
    Type: Grant
    Filed: May 13, 1994
    Date of Patent: October 29, 1996
    Inventor: Yu Wang
  • Patent number: 5546219
    Abstract: In the forward direction, the light from an input fiber is polarized and separated in a polarized light separating and combining element, the separated polarized light is rotated by a polarized light rotating element, dispersed according to wavelength by a wavelength dispersing element, rotated again by the polarized light rotating element, and is further rotated by a phase plate, thereby combining the polarized lights in the polarized light separating and combining element, so that only the light of a desired wavelength is coupled with the optical fiber. In the reverse direction, the light from the output fiber is not coupled with the input fiber, and hence the light propagation direction is defined in one direction in the disclosed optical circuit. A light transmission system and method using this optical circuit is also presented.
    Type: Grant
    Filed: March 3, 1995
    Date of Patent: August 13, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Masanori Iida
  • Patent number: 5521747
    Abstract: A deformable media spatial light modulator utilizes a transmissive deformable media disposed between a deformable transmissive conductor and a substrate. A plurality of electrodes are affixed to the substrate. A potential control is provided to control the potential difference between each electrode and the conductor. A wavefront to be modulated is incident upon the transmissive conductor, traverses the media and is incident upon a reflector, reverses direction, traverses the media a second time and exits the modulator. By allowing the wavefront to be modulated to traverse the media, several enhancements occur including an increase in sensitivity. The increase in sensitivity exhibits a dependence upon the index of refraction of the media.
    Type: Grant
    Filed: January 11, 1994
    Date of Patent: May 28, 1996
    Inventor: Craig D. Engle
  • Patent number: 5521746
    Abstract: A surface deformation type spatial light modulator is electronically addressed by an active matrix array affixed to a second surface of an insulating substrate. Optically reflective electrodes are affixed to the substrate. Each electrode is electrically connected to a respective electronic addressing element by a feedthrough. Overlapping each electrode is a transmissive deformable media layer. Affixed to a first media layer face of the media layer is a transmissive conductor. A potential control is provided to control the potential difference between each electrode and the conductor in accordance with an information bearing signal. A wavefront to be modulated traverses the media, impinges on the electrodes, traverses the media layer a second time before exiting the modulator. Several advantages exist in the invention including increasing the modulation sensitivity of electronic addressed surface deformation type spatial light modulators.
    Type: Grant
    Filed: February 22, 1993
    Date of Patent: May 28, 1996
    Inventor: Craig D. Engle
  • Patent number: 5508841
    Abstract: A phase-contrast DMD based image system 36 for projecting an amplitude and phase modulated image. A flexure beam DMD array 34 is used to allow analog phase modulation of reflected light 38. The phase modulation is converted to amplitude modulation by the phase-contrast imaging optics including a phase plate 42. The resulting amplitude modulated wave is flicker-free and does not need to be synchronized to optical image sensors.
    Type: Grant
    Filed: January 9, 1995
    Date of Patent: April 16, 1996
    Assignee: Texas Instruments Incorporated
    Inventors: Tsen-Hwang Lin, James M. Florence, Michael Leddy, Mark Boysel
  • Patent number: 5508840
    Abstract: A light modulator useful for modulating a diverging light beam exiting from an optical fiber. In one embodiment, the modulator has a focusing lens and two flat partial mirrors. The lens collimates the light, one half of which respectively strikes each of the partial mirrors orthogonally. These mirrors reflect the light back onto itself causing, depending on the relationship between the wavelength of the incident light and the differences in path lengths, varying degrees of constructive or destructive interference. The difference in path length can be varied electrically if the partial mirrors are embodied as etched semiconductor foils which are controllably displaced in an electrostatic field set up between the foils and a substrate electrode.
    Type: Grant
    Filed: November 18, 1993
    Date of Patent: April 16, 1996
    Assignee: Ascom Tech Ltd.
    Inventors: Paul Vogel, Rainer Battig
  • Patent number: 5500587
    Abstract: An E-O probe with improved spatial resolution has a light transmissive base part, an electro-optic material which is fixed to the base part and has an index of refraction which varies in response to an electrical field from a measured object, and a mirror which is fixed to the electro-optic material and reflects an incident beam penetrating the base part and the electro-optic material. The mirror is formed to be smaller than the incident beam in diameter. The electro-optic material is formed very thin.
    Type: Grant
    Filed: September 9, 1993
    Date of Patent: March 19, 1996
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Hironori Takahashi, Shinichiro Aoshima, Isuke Hirano
  • Patent number: 5486946
    Abstract: An array of reflective LCSLM pixels and control circuits formed on a substrate with a light polarizing layer positioned in overlying relationship to the array. A housing having the array and polarizing layer mounted therein, and defining an opening covered by an optical layer with a reflective member affixed to the optical layer. A light source mounted in the housing so that light is directed onto the reflective member and is reflected uniformly onto the polarizing layer. Electrical connections are made from the array, through leads in the housing and to external contacts. The optical layer including a diffuser forming an image plane for reflected light from the array.
    Type: Grant
    Filed: December 21, 1994
    Date of Patent: January 23, 1996
    Assignee: Motorola
    Inventors: Karen E. Jachimowicz, George R. Kelly, Michael S. Lebby
  • Patent number: 5471584
    Abstract: A spatial light modulator of the so-called deformable mirror device (DMD) type has an array of individual mirror ments (20) arranged in lines. The elements are individually driven to change their orientations. Portions (30) of the mirror ments are non-reflecting such as to divide the mirror elements into substantially equal portions forming a greater number of lines of narrower width, with a view to reducing the subjectively visible line structuring.
    Type: Grant
    Filed: August 28, 1993
    Date of Patent: November 28, 1995
    Assignee: Rank Brimar Limited
    Inventors: Peter W. Blaxtan, John Gillespie
  • Patent number: 5467216
    Abstract: A spatial light modulation device of the type, in which information is written to a photoconductor by a light writing portion and read light impinging on a light modulator is reflected by a reflection portion. This spatial light modulation device is provided with a dielectric mirror mounted on a reflection surface of the photoconductor, which surface is opposed to the other surface on which write light is incident. The reflection surface of the photoconductor reflects lights having wavelengths near a wavelength at which the photoconductor has a maximum sensitivity. Thereby, the spatial light modulation device can have a high sensitivity.
    Type: Grant
    Filed: January 31, 1994
    Date of Patent: November 14, 1995
    Assignee: Victor Company of Japan, Ltd.
    Inventors: Masanobu Shigeta, Dai Imanishi, Shigeo Shimizu
  • Patent number: 5455709
    Abstract: Total internal light spatial light modulation apparatus includes a light source for projecting infrared light; a prism for reflecting the projected light from an internal surface therein; and an array of pixel posts made of electrostrictive material and positioned proximate a back face of the internal surface for selectively eliminating pixel areas of reflection of the projected light to form an image thereby. A multiplexer is provided to select a set of pixel posts to be electrically charged which corresponds with the image, and electrical contacts are formed on each pixel post no permit electrical charging of each selected pixel post.
    Type: Grant
    Filed: March 23, 1993
    Date of Patent: October 3, 1995
    Assignee: Martin Marietta Corporation
    Inventors: Thomas C. Dula, III, Paul J. Caldwell, Alex E. Bailey
  • Patent number: 5452121
    Abstract: A variable spectral resolution agile filter has instantly adjustable spectral resolution with no required mechanical motion and a quickly adjustable center wavelength. Adjustment of the center wavelength is accomplished by reliable piezoelectric actuators. Adjustment of the spectral resolution is achieved by changing the finesse of the system, the finesse being governed by the reflectivity of the faces. By making one of the faces exhibit electrically variable reflectivity, the finesse of the system is instantly changeable, and thus the spectral resolution is also instantly changeable.
    Type: Grant
    Filed: November 12, 1993
    Date of Patent: September 19, 1995
    Assignee: Northrop Grumman Corporation
    Inventor: Theodore W. Hilgeman
  • Patent number: 5345328
    Abstract: A wide band optical modulator is grown on a substrate as tandem Fabry-Perot resonators including three mirrors spaced by two cavities. The absorption of one cavity is changed relative to the absorption of the other cavity by an applied electric field, to cause a change in total reflected light, as light reflecting from the outer mirrors is in phase and light reflecting from the inner mirror is out of phase with light from the outer mirrors.
    Type: Grant
    Filed: August 12, 1992
    Date of Patent: September 6, 1994
    Assignee: Sandia Corporation
    Inventors: Ian J. Fritz, Joel R. Wendt
  • Patent number: 5311350
    Abstract: The present invention provides an optical device according to this invention comprising a light transmitting optical member of a high molecular material containing mobile ions, and a pair of electrodes formed on surfaces of the optical member, a required potential difference being provided between the electrodes so as to cause ion conduction in the optical member and to reversibly vary a refractive index of the optical member. According to this invention, a refractive index is reversibly varied due to ion conduction, whereby the modulation of a transmitted beam or a reflected beam by the optical device can be reversibly controlled.
    Type: Grant
    Filed: January 16, 1992
    Date of Patent: May 10, 1994
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Mitsuo Hiramatsu, Isuke Hirano, Tatsuo Fujinami
  • Patent number: 5285308
    Abstract: The present invention relates to a novel spatial light modulator comprising a plurality of individual pixels that each contain separate detectors, electronic circuitry, and optical modulators. A primary application of such a spatial light modulator is to provide the requisite nonlinear relationship between a plurality of optical beams fanned in to each detector on the one hand, and a plurality of optical beams fanned out from such modulator on the other, on a pixel-by-pixel basis. In one embodiment, the spatial light modulator is configured to differentially amplify the inputs to two separate detectors within each pixel, and to transform iORIGIN OF INVENTIONThe U.S. Government has certain rights in this invention pursuant to Contract No. F49620-87-C0007, awarded by the Department of the Air Force, and to Grant No. AFOSR-89-0466, awarded by the Defense Advanced Research Projects Agency through the Department of the Air Force.
    Type: Grant
    Filed: February 13, 1992
    Date of Patent: February 8, 1994
    Assignee: University of Southern California
    Inventors: B. Keith Jenkins, Armand R. Tanguay, Jr.
  • Patent number: 5255118
    Abstract: A technique for reducing interpixel crosstalk in an electrooptic total internal reflection light modulator image bar. A particular electrode length is selected to tailor a portion of the spatial frequency response of the image bar. The pixel size and quality resulting from a voltage difference between electrodes are determined primarily by the overall image bar spatial frequency response, and a set of preferred physical parameters can be determined by selecting parameter values to provide the desired spatial frequency response. It has been found that a desirable frequency response is one that approximates sin(.pi.Pf) for absolute values of f less than about 1/P, where f is the spatial frequency and P is the minimum pixel pitch. Further, it has been found that a particular electrode length provides the desired response for small absolute values of f. The particular electrode length is approximately E.sup.1/2 P/.gamma.
    Type: Grant
    Filed: December 31, 1991
    Date of Patent: October 19, 1993
    Assignee: Xerox Corporation
    Inventor: David L. Hecht
  • Patent number: 5227648
    Abstract: A photodiode array composed of sharply tuned at consecutively different wavelengths are disclosed with the vertical resonance cavity. Semiconductor superlattice distributed Bragg reflectors can be used as the resonance cavity to achieve sharp tuning and monolithic integration, and the wedged distributed Bragg reflector configuration resonance cavity provides a sequential wavelength detection range. A linear array having resolution a fraction of the photodiodes bandwidth and a square-matrix array with a wedged etalon for high resolution, are disclosed. The disclosed photodiode array make a pocket-type wavelength meter feasible and can be used as a substitute for a spectrometer.
    Type: Grant
    Filed: December 3, 1991
    Date of Patent: July 13, 1993
    Inventor: Jong-Chun Woo
  • Patent number: 5218469
    Abstract: A technique for reducing interpixel crosstalk by selecting particular illumination conditions and thus tailoring a portion of the spatial frequency response of an optical image bar. A desirable frequency response is one that approximates sin(.pi.Pf) for absolute values of f less than about 1/P, where f is the spatial frequency and P is the minimum pixel pitch. A skew angle of zero and a grazing angle that is approximately twice the interorder diffraction angle provides the desired cutoff of the response for absolute values of f above about 1/P. The desired frequency response for absolute values of f near zero can be achieved by selecting appropriate values for other physical parameters.
    Type: Grant
    Filed: December 31, 1991
    Date of Patent: June 8, 1993
    Assignee: Xerox Corporation
    Inventor: David L. Hecht
  • Patent number: 5210637
    Abstract: A device for modulating light, wherein a layer of material having a superconducting state is placed in the optical path of a light source and is switched between transparent, non-superconducting and non-transparent, superconducting states by a modulation circuit, thereby providing optical data modulation. A cooling device is provided to maintain the layer of material in its superconducting state. The light source is maintained at a constant optical output which reduces spectral dispersion.
    Type: Grant
    Filed: November 12, 1991
    Date of Patent: May 11, 1993
    Assignee: International Business Machines Corp.
    Inventor: Kenneth A. Puzey
  • Patent number: 5191464
    Abstract: The electrooptic internal reflection modulator of the present invention provides a technique for reducing interpixel crosstalk by using a compensation filter to help define the spatial frequency response of an image bar. The diffraction efficiency of the system is in part defined by a set of properties of the modulator, the illumination and the imaging subsystems, and is characterized by a spatial frequency response. It has been found that a desirable frequency response is one that approximates sin(.pi.Pf) for absolute values of f less then 1/P, where f is the spatial frequency and P is the minimum pixel pitch.
    Type: Grant
    Filed: December 31, 1991
    Date of Patent: March 2, 1993
    Assignee: Xerox Corporation
    Inventor: David L. Hecht
  • Patent number: 5189548
    Abstract: Increasing the addressing capability of an optical image bar having a particular pixel center-to-center spacing (pixel pitch) is accomplished by employing a plurality of N electrodes per pixel. Compared to an optical image bar with one electrode per pixel, this provides N times as many locations for the electric potential transition which establishes the center of the pixel. The provision of multiple electrodes per pixel interval can be used to implement interlacing.
    Type: Grant
    Filed: December 31, 1991
    Date of Patent: February 23, 1993
    Assignee: Xerox Corporation
    Inventor: David L. Hecht
  • Patent number: 5170281
    Abstract: A spatial light modulator includes an electro-optic crystal plate and a mesh electrode for capturing secondary electrons emitted from the crystal plate. Primary electrons carrying an image corresponding to an input optical image are incident on the front surface of the crystal plate to write a charge pattern thereon. In a writing operation, a dc voltage and a ramp voltage is applied to the mesh electrode and the back surface of the crystal plate, respectively. The dc voltage and a variation range of the ramp voltage are shifted to obtain a desired input/output characteristic of the device. Alternatively, a decreasing rate of the ramp voltage is changed to obtain a desired characteristic.
    Type: Grant
    Filed: April 8, 1991
    Date of Patent: December 8, 1992
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Yuji Kobayashi, Tsutomu Hara, Haruyoshi Toyoda