Patents Represented by Attorney Francis J. Caufield

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  • Apparatus and method for modulating the area of pixels for tone reproduction
    Patent number: 5369497
    Abstract: Printing apparatus and method particularly suited to provide a hardcopy of an image produced by medical imaging equipment or the like. The method produces an area modulation hardcopy having a large number of gray levels per area modulation cell (pixel) and a strong density sensitivity. Pixel areas are modulated in patterns consisting of pels which in turn are made up of subpels referred to as slices which are preferably added to minimum sized pels by pulse width modulating two different sized printing radiation beams.
    Type: Grant
    Filed: October 1, 1992
    Date of Patent: November 29, 1994
    Inventors: Janet A. Allen, Guillermo S. Ferla
  • Printing apparatus
    Patent number: 5355303
    Abstract: Printing apparatus particularly suited to provide a hardcopy of an image produced by medical imaging equipment or the like. The apparatus produces an area modulation hardcopy having a large number of gray levels per area modulation cell (pixel) by generating in substantially adfacent columns units of subpixels called pels. The pels have an initial size that is increased by the addition of subpels referred to as slices.
    Type: Grant
    Filed: November 17, 1992
    Date of Patent: October 11, 1994
    Assignee: Polaroid Corporation
    Inventors: Guillermo S. Ferla, Fawwaz N. Habbal
  • Flexible transducers for photon tunneling microscopes and methods for making and using same
    Patent number: 5349443
    Abstract: A flexible transducer for use in a photon tunneling microscope apparatus, the transducer comprising an optically transmissive body having a totally internally reflecting (TIR) surface therein and a second surface plano-parallel to the TIR surface when the TIR surface and the second surface are in an unstressed state, the second surface comprising a combination light energy entrance surface and light energy exit surface, the TIR surface being oriented such that light energy introduced at the second surface within the critical angle normally is reflected totally from the interior of the TIR surface to the second surface. A light pattern of variable intensity emerges from the second surface as a result of frustration of total internal reflection at the TIR surface occuring as the TIR surface is brought sufficiently proximate a sample surface.
    Type: Grant
    Filed: November 25, 1992
    Date of Patent: September 20, 1994
    Assignee: Polaroid Corporation
    Inventor: John M. Guerra
  • Microbench
    Patent number: 5343546
    Abstract: In a laser light pump, a multiplicity of micromanipulators adjust the positions of a cylindrical lens and line of optical fiber ends relative to each other and relative to a light source composed of a line of laser diode facets. Each micromanipulator achieves extremely fine resolution by imposing a vernier or differential screw arrangement into a flexure ratio divider, and thereby multiplying its resolving capability. The vernier screw arrangement spreads two members of different stiffnesses, and the stiffer one of the members moves the lens or the line of fiber ends.
    Type: Grant
    Filed: March 26, 1993
    Date of Patent: August 30, 1994
    Assignee: Polaroid Corporation
    Inventors: David V. Cronin, Louis J. Brozyna
  • Hot sprue bushing with interchangeable tip having multiple edge gates
    Patent number: 5334006
    Abstract: A highly reliable hot sprue bushing with an interchangeable tip having multiple edge gates for use in controlling the temperature of plasticized material while it flows from the injection nozzle to the gates of a multiple cavity mold. Advantageously, the hot sprue bushing is adjustable in length so that it can be used with a full range of standard or custom mold plate thicknesses or other required lengths and the interchangeable tip does not require separate heating and temperature control.
    Type: Grant
    Filed: December 21, 1992
    Date of Patent: August 2, 1994
    Assignee: Polyshot Corporation
    Inventors: Douglas C. Hepler, David L. Pursel
  • Compact objective lens
    Patent number: 5327291
    Abstract: A lens system for a folding reflex camera is provided. The system includes: (a) a first group on the object side of the system's stop which (i) has a positive dioptric power, (ii) includes an aspheric surface, and (iii) has a concave surface adjacent to the stop; and (b) a second group on the image side of the stop consisting of either a single positive component or the combination of a single positive component and one or more focusing elements. The system includes at least two elements made of materials differing in dispersive powers where at least one of the elements is of plastic. The system can comprise just two plastic elements and even with such a simple configuration achieves excellent optical performance including a relatively flat field, relatively low distortion, and at least partial correction for lateral chromatic aberration.
    Type: Grant
    Filed: March 30, 1992
    Date of Patent: July 5, 1994
    Assignee: Polaroid Corporation
    Inventors: James G. Baker, William T. Plummer, Jon Van Tassell
  • Optical fiber laser and geometric coupler
    Patent number: 5268978
    Abstract: In an optical coupling system for a fiber laser, a cylindrical lens extends parallel to a number of aligned light sources and a series of aligned input ends of optical fibers facing the light sources. Output ends of the fibers pass light to a solid state medium in a laser cavity. A block with precision grooves holds the fibers to align them with the lens and the images of the light sources. The cylindrical lens is biaspheric with a longitudinal axis and two refractive surfaces whose axially transverse cross-sections follow paths other than the paths of a conic section.
    Type: Grant
    Filed: December 18, 1992
    Date of Patent: December 7, 1993
    Assignee: Polaroid Corporation
    Inventors: Hong Po, Stephen D. Fantone
  • Methods and means for reducing temperature-induced variations in lenses and lens devices
    Patent number: 5260828
    Abstract: A lens composed of a single material and having at least one refractive surface on one face and a kinoform on the other face. The purely refractive between the surfaces varies dimensionally and in refractive index in response to temperature changes and thereby changes a characteristic, such as back focal length, of the lens while the kinoform varies differently in response to the same temperature changes. The kinoform power is sufficient to vary the temperature induced characteristic changes of the lens in an opposing sense at a given wavelength and in an amount sufficient to athermalize the optical device. In one embodiment the kinoform power compensates for the combined temperature-induced effects upon the refractive portion and any mount that supports the lens.
    Type: Grant
    Filed: March 27, 1992
    Date of Patent: November 9, 1993
    Assignee: Polaroid Corporation
    Inventors: Carmina Londono, William T. Plummer
  • Area modulation printing apparatus
    Patent number: 5221971
    Abstract: Printing apparatus and method particularly suited to provide a hardcopy of an image which is produced by medical imaging equipment or the like. The apparatus produces hardcopy consisting of pixels whose size can be changed by area modulation to suit image tonal content and detail while still maintaining a large number of gray levels per area modulation cell (pixel). Preferably, the same area modulation patterns representing pixel tonal values are used for printing pixels of different sizes.
    Type: Grant
    Filed: November 21, 1990
    Date of Patent: June 22, 1993
    Assignee: Polaroid Corporation
    Inventors: Janet A. Allen, Daniel P. Bybell, Dana F. Schuh, Jay E. Thornton
  • Adjustable hot sprue bushing
    Patent number: 5213824
    Abstract: A highly reliable hot sprue bushing for use in controlling the temperature of plasticized material while it flows from the nozzle to the runner or sprue system in an injection molding machine. Advantageously, the hot sprue bushing is adjustable in length so that it can be used with a full range of standard or custom mold plate thicknesses or other required lengths.
    Type: Grant
    Filed: March 19, 1992
    Date of Patent: May 25, 1993
    Assignee: Polyshot Corporation
    Inventor: Douglas C. Hepler
  • Printing method
    Patent number: 5170261
    Abstract: Printing apparatus and method particularly suited to provide a hardcopy of an image which is produced by medical imaging equipment or the like. The method produces an area modulation hardcopy having a large number of gray levels per area modulation cell (pixel) and a strong density sensitivity preferably by pulse width modulating two different sized printing radiation beams.
    Type: Grant
    Filed: November 21, 1990
    Date of Patent: December 8, 1992
    Assignee: Polaroid Corporation
    Inventors: Ellen B. Cargill, Fawwaz N. Habbal, Andrew K. Juenger
  • Radiation source for a printer
    Patent number: 5161064
    Abstract: Source of laser radiation for a printer includes at least one laser diode array and an optical system which is telecentric in at least one azimuth for imaging the near field distribution from the laser diode array(s) on a recording medium.
    Type: Grant
    Filed: November 21, 1990
    Date of Patent: November 3, 1992
    Assignee: Polaroid Corporation
    Inventors: Peter P. Clark, Carmina Londono
  • Dynamic focusing system for use with discontinuous medium
    Patent number: 5159352
    Abstract: A printing system employs a rotating drum for carrying a photosensitive printing medium in the form of a discontinuous sheet, there being a clamp carried by the drum and rotating therewith for holding ends of the sheet to secure the sheet to the drum. The system includes a print head having a laser beam which is spatially and temporally modulated for gray-scale printing of individual pixels of an image. The head is scanned parallel to an axis of the drum. A servomechanism responsive to angular orientation of the drum produces a linear scan during rotation of the drum. An optical system within the head provides a common path through a common objective lens for both a write laser beam and for a focus laser beam of an automatic focusing apparatus which positions the objective lens rapidly by a dither motion to compensate for undulations in the surface of the print medium.
    Type: Grant
    Filed: January 15, 1992
    Date of Patent: October 27, 1992
    Assignee: Polaroid Corporation
    Inventors: Guillermo S. Ferla, Walter P. Haimberger, Robert F. Hartmann
  • Golf bag compartmentalizer
    Patent number: 5148915
    Abstract: This invention is a lightweight, inexpensive insert for partitioning the interior space of a conventional golf bag into separate compartments for storing one or more golf clubs so that they will not bind when transferring them to and from the bag. The insert is made of a durable, high strength cloth or fabric such as nylon or equivalent material and is suspended from the dividing bars of the bag by flaps and hook and loop materials while its bottom, in a preferred form, is retained in place via a base plate which provides resistance to turning and lateral movement.
    Type: Grant
    Filed: August 30, 1991
    Date of Patent: September 22, 1992
    Inventor: Daniel P. Ryan
  • Laser driver with plural feedback loops
    Patent number: 5123023
    Abstract: A laser driver circuit pulses of current to a laser diode to activate the diode to emit pulses of radiation suitable for operation of a laser printer. A field-effect transistor (FET) is serially connected with the laser diode and with a feedback resistor for applying the current pulses, the feedback resistor serving as a source of a feedback signal indicative of the magnitude of current flow. A photodetector senses radiation outputted by the laser diode and emits an optical feedback signal representative of radiated power of the laser diode. A combiner circuit, responsive to an input digital command signal, combines the current feedback signal and the optical feedback signal with the command signal to signal generate a drive signal for activating the FET.
    Type: Grant
    Filed: November 21, 1990
    Date of Patent: June 16, 1992
    Assignee: Polaroid Corporation
    Inventors: Bryan A. Santarelli, Marc T. Thompson
  • Bulk optic wavelength division multiplexer
    Patent number: 5119454
    Abstract: An optical multiplexing/demultiplexing device combines an etalon and weak diffraction grating along with temperature control to finely tune local resonant stations along the etalon to separate and/or combine a plurality of optical signals that are finely spaced in wavelength.
    Type: Grant
    Filed: May 23, 1988
    Date of Patent: June 2, 1992
    Assignee: Polaroid Corporation
    Inventor: Donald H. McMahon
  • Endoscopic gradient index optical systems
    Patent number: 5093719
    Abstract: Gradient index endoscopic or borescopic systems in forms ranging from basic to more complex depending on the optical task. The basic form comprises a gradient index objective of less than a quarter period in length followed by a gradient index relay whose length is at least one-quarter period longer than the distance of the first image of the object into the relay. The numerical aperture of the objective is preferably larger than that of the relay to provide a wide angle endoscope with an "entrance aperture tunnel" preceding the objective. In one embodiment with a line-of-view prism the entrance tunnel is placed in the most restricted aperture within the prism thus minimizing or eliminating vignetting of the field of view. A second embodiment of this subsystem is an endomicroscope wherein the entrance pupil moves and changes size as the ocular focus of the system is changed.
    Type: Grant
    Filed: October 23, 1989
    Date of Patent: March 3, 1992
    Assignee: Manx Optical Corporation
    Inventor: Rochelle Prescott
  • Holographic optical data storage medium
    Patent number: 4999234
    Abstract: A hologram is fabricated by opening a volume phase reflection hologram formed in a recording medium such as a positive photoresist. The opening occurs by forming a second hologram, such as an off-axis hologram, in the same recording medium. The opened hologram can be replicated in metal and the metal can be used to emboss the fringe pattern of the opened hologram into plastic. A full range of colors in the visible spectrum may be obtained by metallizing the embossed plastic structure and then by overcoating it with appropriate clear dielectric layers.
    Type: Grant
    Filed: June 10, 1988
    Date of Patent: March 12, 1991
    Assignee: Polaroid Corporation
    Inventor: James J. Cowan
  • Apparatus and method utilizing an LCD for printing
    Patent number: 4992824
    Abstract: Method and apparatus which utilize an LCD modulator array for printing and/or enlarging an image recorded in a color film negative, a positive transparency or a color print, which LCD modulator array has pixels whose "closing time" (the time it takes to convert a pixel from a condition wherein it transmits radiation to a condition wherein it blocks radiation) is substantially longer than their "opening time" (the time it takes to convert a pixel from a condition wherein it blocks radiation to a condition wherein it transmits radiation). In accordance with the present invention, each pixel of the LCD modulator array is opened and closed in a rapid sequence, one after the other, at intervals which are much shorter than the closing time of the pixels of the LCD modulator array.
    Type: Grant
    Filed: July 31, 1989
    Date of Patent: February 12, 1991
    Assignee: Polaroid Corporation
    Inventor: William T. Plummer
  • Anti-aliasing optical system with pyramidal transparent structure
    Patent number: 4989959
    Abstract: Optical, low-pass filter, anti-aliasing apparatus for an array of photosensor elements is a substantially wavelength independent optical, low-pass phase filter formed from a substantially transparent, convex or concave pyramidal structure.
    Type: Grant
    Filed: June 12, 1989
    Date of Patent: February 5, 1991
    Assignee: Polaroid Corporation
    Inventor: William T. Plummer