Patents by Inventor Louis F. Schaefer
Louis F. Schaefer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 5604838Abstract: The present invention relates to video recording and playback techniques and devices which create relative movement between a laser and an optical medium such as a flexible optical tape to permit recording of relatively high bandwidth signals. Further, the present invention relates to video recording and playback techniques and devices which optimize relative movement between a laser source and the optical medium in a cost-effective manner. Data spots having a set of predetermined feature sizes (i.e., set of varying hole sizes) can thus be recorded at a rate useful for high bandwidth signals (e.g., television video signals). Further, recording on a flexible optical medium (e.g., optical tape) can be performed in a manner which optimizes space efficiency on the tape.Type: GrantFiled: November 15, 1994Date of Patent: February 18, 1997Assignee: Samsung Electronics Co., Ltd.Inventor: Louis F. Schaefer
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Patent number: 5557418Abstract: Digital video information recorded on a recording medium is read from the medium by scanning a fraction of a video signal field stored on the recording medium during a scan cycle over the recording medium, reading data during the scan cycle, which data includes video signal information and video signal identification information, and storing at least a portion of the video signal information in a field memory at a location identified by the video signal identification information.Type: GrantFiled: December 9, 1993Date of Patent: September 17, 1996Assignee: Samsung Electronics Co., Ltd.Inventor: Louis F. Schaefer
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Patent number: 5343458Abstract: The present invention relates to video recording and playback techniques and devices which create relative movement between a laser and an optical medium such as a flexible optical tape to permit the recording of different bandwidth signals. Further, the present invention relates to video recording and playback techniques and devices which optimize relative movement between a laser source and the optical medium in a cost-effective manner.Type: GrantFiled: September 15, 1992Date of Patent: August 30, 1994Assignee: SamSung Electronics Co., Ltd.Inventors: Louis F. Schaefer, Hugh E. Frohbach, Gerald A. Pierce, Norman A. Peppers
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Patent number: 5321684Abstract: In a preferred embodiment, the invention relates to systems and methods for storing digital video information on an optical recording medium comprising the steps of moving the optical recording medium in a first direction, sinusoidally scanning a beam of light over the moving optical recording medium in a second direction substantially perpendicular to the first direction to establish a scan path over the optical recording medium, and periodically deflecting the sinusoidal scanning beam in the first direction to linearize at least a portion of the scan path. By linearizing at least a portion of the scan path, two traces can be made per cycle of a primary sinusoidal deflection, thereby doubling scanning efficiency.Type: GrantFiled: September 15, 1992Date of Patent: June 14, 1994Assignee: SRI InternationalInventors: Louis F. Schaefer, Hugh F. Frohbach, Norman A. Peppers
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Patent number: 4791494Abstract: A photographic printer for producing a visible image of information received in the form of a plurality of discrete electrical signals in which the signals are applied respectively to a plurality of devices each of which acts as a source of light in response to an electrical signal and which devices are arranged in an array adjacent to a photosensitive surface to direct light thereon in response to said signals thus to produce an image of the information on the surface. It is preferred form the printer is an electrophotographic printer in which the photosensitive surface is a charged photoconductor so that light from the sources produces a latent electrostatic image which may be developed and transferred to plain paper, for example.Type: GrantFiled: April 30, 1984Date of Patent: December 13, 1988Assignee: Savin CorporationInventor: Louis F. Schaefer
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Patent number: 4730293Abstract: An optical data reading and writing system in which a laser beam records data spots on a medium and a wide light beam is used for simultaneously reading the data spots and prerecorded information. The laser beam records spots of a uniform size which is less than about ten micrometers. The wide beam which may be emitted by an LED illuminates a substantially larger area of the medium than the laser beam. Prerecorded information, if present, may include parallel track lines, the wide beam illuminating adjacent pairs of track lines in addition to the data spots and prerecorded clock spots in data tracks between the track lines. Multiple data paths may be present between track lines, which may then be read simultaneously by a photodetector. The photodetector may have a plurality of detector elements which have apertures such that simultaneously illuminated data spots are distinguished.Type: GrantFiled: September 15, 1986Date of Patent: March 8, 1988Assignee: Drexler Technology CorporationInventors: Gerald A. Pierce, Louis F. Schaefer, Norman A. Peppers, William F. Mullen
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Patent number: 4714310Abstract: Beam focusing and scanning method and apparatus are shown comprising a plane mirror (40) upon which a laser beam (32) is directed through a focusing lens (38). The beam is reflected back through the focusing lens (38) onto a pivotal mirror (52). The plane mirror (40) is movable back and forth along the beam axis, and the movement of plane mirror (40) and pivotal mirror (52) is synchronized whereby the beam is focused at the face of an object (54) while scanned across the object.Type: GrantFiled: April 21, 1986Date of Patent: December 22, 1987Assignee: SRI InternationalInventors: Norman A. Peppers, Louis F. Schaefer
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Patent number: 4480179Abstract: An apparatus for coding and/or decoding a document, comprising a light path (27,28,29) formed of optic fibres and capable to direct light from a lens for focusing the light from a document to be coded or decoded to a light-sensitive device for recording a coded and, respectively, decoded copy of an uncoded and, respectively, coded document. The light path (27,28,29) consists at least along a section of a coding and/or decoding unit (29) comprising a code disc (32) provided with optic fibres (62), the respective ends of which are connected to a first and, respectively, second light guide (27 and, respectively, 28), associated with the light path. The fibres (62) at one end surface of the code disc (32) have a different mutual order than at the other end surface of the code disc. The fibres (62) of the code disc (32) and the fibres (60,61) of the light guides (27, 28) at the end surfaces of the code disc (32) and, respectively, at the ends of the light guides ( 27,28) are located along a circle.Type: GrantFiled: September 21, 1982Date of Patent: October 30, 1984Assignee: Esselte Nordia ABInventors: Louis F. Schaefer, Termpoon Kovattana, Tommy Henningson
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Patent number: 4410968Abstract: Information is stored, using a relatively low-power light beam, by redistributing the material in a deformable film. In a disc configuration, positioning of the light beam is achieved by referencing to a previously recorded track. In a document storage and retrieval system the document is scanned with the resultant scanned signal modulating the writing light beam producing a recorded track. This track is optically read with the resultant signal applied to a printer. For optimum utilization of the area, the recording and readout take place at constant velocity.Type: GrantFiled: September 16, 1980Date of Patent: October 18, 1983Assignee: Thomas Lee SiweckiInventors: Hugh F. Frohbach, Robert E. Myers, Norman A. Peppers, Thomas L. Siwecki, Louis F. Schaefer
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Patent number: 4310847Abstract: A color image is recorded on film at the television field rate. A portion of the film is illuminated, corresponding to a line in the color image, and decomposed into its component colors. The decomposed light from the line is imaged onto two or more line scanning photosensitive arrays which provide scanned signals. These scanned signals are decoded and used to provide the standard color television signals.Type: GrantFiled: August 4, 1978Date of Patent: January 12, 1982Assignee: World Development LaboratoriesInventors: Hugh F. Frohbach, Albert Macovski, Norman A. Peppers, Thomas L. Siwecki, Louis F. Schaefer
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Patent number: 4261007Abstract: A color image is recorded on film at the television field rate with alternate film frames representing the luminance and chrominance information. The chrominance information is encoded by filtering the color image through a striped color filter. On playback two line scanners are used to simultaneously scan the luminance and chrominance frames to provide the desired information simultaneously. A decoding signal is used to decode the encoded chrominance information and derive color-difference signals.Type: GrantFiled: June 4, 1979Date of Patent: April 7, 1981Assignee: Laser-File Inc.Inventors: Hugh F. Frohbach, Robert E. Myers, Norman A. Peppers, Thomas L. Siwecki, Louis F. Schaefer, Albert Macovski
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Patent number: 4205338Abstract: A prerecorded track on a disc is automatically tracked resulting in a radial tracking signal. Components of this signal are stored during a prerecording interval. During recording these stored components are used to produce a restored radial tracking signal which is used to radially position the recording energy source and keep the newly recorded tracks at a fixed distance from the previously recorded tracks.Type: GrantFiled: November 3, 1977Date of Patent: May 27, 1980Assignee: Laser File Inc.Inventor: Louis F. Schaefer
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Patent number: 4141347Abstract: Pulsed real-time B-scan ultrasonic method and apparatus are disclosed together with pulsed Doppler Ulrasonic method and apparatus. The B-scan apparatus includes a pulse operated transmitter and receiver operating at a first frequency, and the Doppler apparatus includes a pulse operated transmitter and receiver operating at a second frequency sufficiently far removed from the B-scan frequency to avoid interference therebetween. A synchronous pulse operation of the B-scan and Doppler systems is provided. The sysem includes a visual display means to which the receiver outputs are connected through a multiplexer operated to pass the B-scan receiver output to the visual display means whenever such B-scan output is present. The Doppler apparatus includes means for temporarily storing the Doppler receiver output, which stored Doppler signals subsequently are read out through the multiplexer to the visual display means between select lines of B-scan display.Type: GrantFiled: September 21, 1976Date of Patent: February 27, 1979Assignee: SRI InternationalInventors: Philip S. Green, Louis F. Schaefer, Jon C. Taenzer, John F. Holzemer, S. David Ramsey, Jr., Joe R. Suarez
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Patent number: 4006292Abstract: An information transfer system having a high information transfer rate of the type utilizing a storage medium and associated transducer means, the combination including a movable storage medium having an information path formed thereon and having an information storage capacity. Transducer means is adapted to sequentially scan the information stored along said information path and respond to information stored along said path. The combination further includes a first information reproduction channel including a first information track formed along said path on said medium and a first transducer responsive to said first track, said first channel having a rate limited information transfer capacity of C1 and a second information reproduction channel including a second information track formed along said path on said medium and a second transducer responsive to said second track, said second channel having a rate limited information transfer capacity of C2.Type: GrantFiled: September 3, 1974Date of Patent: February 1, 1977Assignee: Sharp CorporationInventor: Louis F. Schaefer
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Patent number: 3999687Abstract: A toner concentration detecting and toner replenishing system for use in an electrostatic copier having a magnetic brush which carries dry developer comprising a mixture of ferromagnetic carrier particles and toner particles into contact with the surface of a photoconductor upon which a latent electrostatic image has been formed, in which system a quantity of developer is removed from the magnetic brush after development of the image and the brush leaves the surface. The removed developer is directed into a dielectric tube having a restricted outlet which inhibits unstable flow through the tube so that developer in the tube determines the inductance of a coil surrounding the tube. The coil is one element of the tuned circuit of a sensing oscillator, the output frequency of which is compared with that of a tunable reference oscillator to provide a frequency difference signal which is a measure of the relative proportion of toner to carrier in the developer.Type: GrantFiled: November 17, 1975Date of Patent: December 28, 1976Assignee: Savin Business Machines CorporationInventors: James A. Baer, Charles B. Clark, Louis F. Schaefer
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Patent number: 3981267Abstract: An electrophotographic liquid developing system for overcoming the effect of photoconductor background potential in which during the passage of the image area through the developer unit a constant current source supplies a small current to the development electrode to raise the electrode to a potential of the same polarity as and of a magnitude greater by predetermined amount than that of the average background potential of the image area. In a preferred embodiment the constant current source is provided by a small plate mounted in and insulated from the transfer corona housing and having such dimensions as to provide the required current. Preferably, the output of the constant current source is controlled in response to a measurement of the conductivity of the developer.Type: GrantFiled: May 20, 1975Date of Patent: September 21, 1976Assignee: Savin Business Machines CorporationInventors: Kenneth W. Gardiner, Louis F. Schaefer
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Patent number: 3980811Abstract: A contacting pickup optical waveguide reproduction system and method for reproducing information carried on a recording medium. The recording medium is of the type having optically reflective pits formed in an information path. Information is stored as a function of pit modulation. The system includes an optical pickup adapted to slidably contact an information path along a recording medium and means for illuminating the pits. Optical waveguide means is provided for receiving illumination reflected by said pits and an optical-to-electrical energy transducer is coupled to said optical waveguide means. A particular embodiment includes a remote optical-to-electrical energy transducer.Type: GrantFiled: September 3, 1974Date of Patent: September 14, 1976Assignees: Nihon Denshi Kabushiki Kaisha, Sharp Kabushiki KaishaInventors: Louis F. Schaefer, Philip J. Rice, Hugh F. Frohbach
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Patent number: 3970036Abstract: A toner concentration detecting and toner replenishing system for use in an electrostatic copier having a magnetic brush which carries dry developer comprising a mixture of ferromagnetic carrier particles and toner particles into contact with the surface of a photoconductor upon which a latent electrostatic image has been formed, in which system a quantity of developer is removed from the magnetic brush after development of the image and the brush leaves the surface. The removed developer is directed into a dielectric tube having a restricted outlet which inhibits unstable flow through the tube so that developer in the tube determines the inductance of a coil surrounding the tube. The coil is one element of the tuned circuit of a sensing oscillator, the output frequency of which is compared with that of a tunable reference oscillator to provide a frequency difference signal which is a measure of the relative proportion of toner to carrier in the developer.Type: GrantFiled: July 17, 1974Date of Patent: July 20, 1976Assignee: Savin Business Machines CorporationInventors: James A. Baer, Charles B. Clark, Louis F. Schaefer
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Patent number: RE30477Abstract: An electrophotographic liquid developing system for overcoming the effect of photoconductor background potential in which during the passage of the image area through the developer unit a constant current source supplies a small current to the development electrode to raise the electrode to a potential of the same polarity as and of a magnitude greater by predetermined amount than that of the average background potential of the image area in a preferred embodiment the constant current source is provided by a small plate mounted in and insulated from the transfer corona housing and having such dimensions as to provide the required current. Preferably, the output of the constant current source is controlled in response to a measurement of the conductivity of the developer.Type: GrantFiled: May 10, 1979Date of Patent: January 13, 1981Assignee: Savin CorporationInventors: Kenneth W. Gardiner, Louis F. Schaefer
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Patent number: RE31964Abstract: An automatic control system for the bias on a development electrode in which a plurality of ground-insulated, narrow floating electrodes are spaced along a line adjacent the entrance of a liquid developer applicator unit. The floating electrodes relatively scan image areas of the surface of an organic photoconductor carried by a conductive support moving through the developer unit. Owing to conduction of a charge from the photoconductive surface through the developer liquid to the floating electrodes, they assume potentials each of which is a function of the average potential of the image area subtended by the floating electrode. The potential of each floating electrode is sensed by a high input impedance measuring circuit which selects the potential of the lowest value, amplifies the selected potential and applies the amplified voltage to the biasing electrode or electrodes of the developer system.Type: GrantFiled: June 27, 1983Date of Patent: August 6, 1985Assignee: Savin CorporationInventors: Louis F. Schaefer, Kenneth W. Gardiner