Patents Represented by Attorney Leonard Zalman
  • Patent number: 4138635
    Abstract: Parallel connections are provided from high voltage power supplies of opposite polarities through separate light dependent resistors to an electrical load. Separate light emitting diodes are associated with each of the light dependent resistors and are driven by a differential amplifier having one reference input and another input responsive to load current or voltage. The load current or voltage is regulated or programmed through a relatively low voltage power supply and a programmed or regulated amplifier which manipulates the illuminating effect of the light emitting diodes to vary the resistance of the light dependent resistors in a prescribed manner. This manipulation of the resistances imposed in the parallel power leads produces an alternating current across the load. The reference input to the differential amplifier is preferably adjustable.
    Type: Grant
    Filed: June 9, 1977
    Date of Patent: February 6, 1979
    Assignee: Xerox Corporation
    Inventor: Halsey P. Quinn
  • Patent number: 4133432
    Abstract: A goblet-type receptacle holder characterized by a plurality of receptacle receiving channels on each side of a central inlet channel with which the receiving channels communicate. The receiving channels can be defined by the parallel disposed legs of substantially W-shaped members. A first pair of substantially U-shaped members connected to the W-shaped members at the ends thereof remote from the inlet channel provide support for the holder via fasteners passed therebetween and a second pair of substantially U-shaped members provide additional support for the first pair of U-shaped members. The second pair of U-shaped members also provide for interconnecting and rigidizing the holder components. The character-shaped members and other support and linkage rods can be metallic rods or strips and can be of a material susceptible to resistance welding.
    Type: Grant
    Filed: October 4, 1976
    Date of Patent: January 9, 1979
    Inventor: William E. Den Blaker
  • Patent number: 4132960
    Abstract: A heterojunction laser in which single longitudinal mode operation is achieved by heavily doping the active region of the laser. The dopent density should be approximately 10.sup.19 /cm.sup.3 when the dopent is zinc. A doping density as heavy as possible should be used when the dopent is germanium or any other acceptor impurity. The heavy doping density of the active region excludes the injection of holes into the active region and that exclusion results in single longitudinal mode operation.
    Type: Grant
    Filed: March 28, 1977
    Date of Patent: January 2, 1979
    Assignee: Xerox Corporation
    Inventors: William Streifer, Donald R. Scifres, Robert D. Burnham
  • Patent number: 4126711
    Abstract: A liquid developer is presented to a charge pattern on a photoconductor surface as an evenly distributed array of droplets passing tangentially to it. The droplets emanate from a series of jets and are spread into an even pattern electromagnetically. The charge pattern is developed by the droplet which it draws to the photoconductor surface.
    Type: Grant
    Filed: September 4, 1975
    Date of Patent: November 21, 1978
    Assignee: Xerox Corporation
    Inventor: Richard Z. Marlow
  • Patent number: 4126824
    Abstract: A progressively shorted tapered resistance device including a body of material which undergoes an irreversible resistance decrease when heated beyond a threshold temperature in operative association with a tapered electrical resistance element which develops a non-uniform temperature profile when electrically energized. Upon sufficient energization, the tapered resistor element will cause portions of the heat sensitive material to be heated beyond its threshold temperature resulting in a shorting out of a portion of the tapered resistance element. The amount of the tapered resistance element shorted out is measured at low currents to provide an indication of the energizing current.
    Type: Grant
    Filed: April 21, 1977
    Date of Patent: November 21, 1978
    Assignee: Xerox Corporation
    Inventors: David D. Thornburg, Roy J. Lahr
  • Patent number: 4126894
    Abstract: A mapping arrangement for memory overlay wherein the address coordinates are referenced to a main serial memory. This main memory is partitioned into pages of equal size. An accelerator memory is concurrently loaded with a few pages representing a small portion of the main memory contents and is periodically overlayed with new memory contents on a page-at-a-time basis as the using system demands. During this overlay the fields of the accelerator memory are inscribed at corresponding main memory address coordinates together with code bits indicating whether certain memory fields go together and are therefore promoted as a single unit. The resulting effect is to cause an apparent increase in page size since more than one page is promoted as a consequence of a reference to a page not contained in the accelerator memory.
    Type: Grant
    Filed: February 17, 1977
    Date of Patent: November 21, 1978
    Assignee: Xerox Corporation
    Inventors: David Cronshaw, James R. Keddy, Jack E. Shemer, William D. Turner
  • Patent number: 4126893
    Abstract: A memory control processor adapted to expand a random access or accelerator memory by logical overlays which performs these overlays into memory fields (pages) on the basis of page usage history. To provide a quick reference to page use a chronological sequence is established by links rather than by reordering a stack. This link sequence is tied by very limited leads to the rest of the memory control processor and can therefore be updated during each memory access. In addition the memory control processor includes a task priority logic integrating various competing memory access requests with the overlay operations. To achieve the various transfer modes in the quickest time the memory control processor is organized around a wide control memory storing the task servicing sequences. The width of the control memory and the associated task logic allow general purpose microprogrammable direct memory access which may further be utilized in multiplexed fashion to accommodate various concurrent tasks.
    Type: Grant
    Filed: February 17, 1977
    Date of Patent: November 21, 1978
    Assignee: Xerox Corporation
    Inventors: David Cronshaw, William D. Turner, Jack E. Shemer
  • Patent number: 4121153
    Abstract: An improved analog meter is provided having no moving parts. This meter comprises a tapered resistor device having a tapered, electrically resistive element which develops a non-uniform temperature profile on electrical energization and a heat sensitive element operatively associated with the tapered resistive element. The heat sensitive medium employed is a reversible medium which either undergoes a change in color or contrast when heated to an appropriate temperature and when viewed under appropriate illumination. A method of metering employing this device is also disclosed.
    Type: Grant
    Filed: December 3, 1976
    Date of Patent: October 17, 1978
    Assignee: Xerox Corporation
    Inventor: David D. Thornburg
  • Patent number: 4119907
    Abstract: An apparatus for substantially eliminating the effects of a nonsinusoidal current from a reactive or nonlinear load as applied to a resistive load requiring an input current that appears to be sinusoidal. If the amplitude of the current source as applied to the resistive load can be controlled through a switching regulator by matching a sine wave reference signal with current inputed from the current source then said input current may be forced into a sinusoidal mode that is in phase with the voltage thereof. Accordingly, with the input current in a phased sinusoidal condition, harmonic elimination and power factor correction may be afforded to the inputed power relative to the resistive load.
    Type: Grant
    Filed: May 27, 1977
    Date of Patent: October 10, 1978
    Assignee: Xerox Corporation
    Inventor: Halsey P. Quinn
  • Patent number: 4118112
    Abstract: A tapered resistor device which includes generally a tapered resistive film comprising a semiconducting material or other suitable material with a negative temperature coefficient of resistivity is provided. It is apparent with reference to the curves which show the variation of .DELTA.E that large energy savings are possible at the narrow end of the taper with relatively small concomitant degradation in the temperature profile of the region of interest. It is therefore seen that employing a material with a negative temperature coefficient of resistivity provides an improvement in reducing power usage according to the principles of the instant invention.
    Type: Grant
    Filed: December 3, 1976
    Date of Patent: October 3, 1978
    Assignee: Xerox Corporation
    Inventor: David D. Thornburg
  • Patent number: 4115765
    Abstract: An autonomous processor for displaying on a video tube both text characters and facsimile data. To conserve memory space the facsimile data is stored in compressed form and is decompressed or unfolded in synchronism with the vertical and horizontal deflections in the video tube. Similarly the text characters are stored in coded form, together with interspaced commands, both inscribed in a list memory. Each character code in the list then selects an appropriate dot matrix from a font memory which also contains displacement data. Selected lines of the font dot matrices are then addressed by row coordinates to form a horizontal video signal, which is accumulated in a ping pong buffer concurrently unloading into a video register. This same video register merges the facsimile data which is concurrently unfolded.
    Type: Grant
    Filed: February 17, 1977
    Date of Patent: September 19, 1978
    Assignee: Xerox Corporation
    Inventor: David Hartke
  • Patent number: 4112389
    Abstract: A diode laser having an active region which has a section in the shape of a closed loop or ring, with the path length of the loop or ring causing a light wave traveling completely around the loop or ring section from a coupler section of the active region to undergo a phase shift of 180.degree. relative to its starting phase whereby the two waves interfere destructively, and thus provide optical feedback.
    Type: Grant
    Filed: January 21, 1977
    Date of Patent: September 5, 1978
    Assignee: Xerox Corporation
    Inventors: William Streifer, Donald R. Scifres, Robert D. Burnham
  • Patent number: 4111521
    Abstract: A semiconductor device which utilizes interferometric principles and electrical control to provide either light reflection or light transmission or partial light reflection/transmission. In a preferred embodiment, the device includes an input waveguide which divides into branch waveguides, with the branch waveguides being reunited at an output waveguide. When the optical path lengths of the branched waveguides varies by an integer multiple of the light wavelength in the guides, the light waves interfere constructively at the output waveguide causing light to be transmitted into the output waveguide. When the light wave in one branch waveguide undergoes a single pass phase shift of 180.degree. relative to the light wave in the other branch waveguide, the light waves interfere at the output waveguide and are caused to return to the input waveguide through the branch waveguides. The returning light wave in the one branch waveguide once again experiences a single pass 180.degree.
    Type: Grant
    Filed: January 21, 1977
    Date of Patent: September 5, 1978
    Assignee: Xerox Corporation
    Inventors: William Streifer, Donald R. Scifres, Robert D. Burnham
  • Patent number: 4110823
    Abstract: A distributed function processing system utilizing a conventional microprocessor operated as a text processor in combination with a plurality of other autonomous processing devices arranged to operate in a coherent processing system. One of the autonomous processors which is a memory control processor serves to periodically overlay a random access accelerator memory with the contents of a main memory system and concurrently resolves conflicts among various other autonomous memory service requests. This processor, therefore, accommodates the data rates of the main memory. The other processor is a display processor which generates signals to a video display system to provide a visual interface to the user and is therefore tied to the video rate. Accordingly, the processing burden is distributed within processors entailing differing rates operating autonomously.
    Type: Grant
    Filed: February 17, 1977
    Date of Patent: August 29, 1978
    Assignee: Xerox Corporation
    Inventors: David Cronshaw, Jack E. Shemer, William D. Turner, David Hartke, James R. Keddy, Wilbur E. DuVall, Warren M. Sterling
  • Patent number: 4104515
    Abstract: A consumable credit card is provided which comprises a recording device that is adapted to receive progressively advancing recording up to a limit at which time the card is consumed and thereafter is discarded. The card is adapted to be inserted into a reader which accepts, reads and advances the indication on the credit card or reading to indicate an additional use until the credit card is expended and the reader no longer allows the item or service to be dispensed because the credit card has been expended. This credit card employs tapered resistor technology in order to store a permanent record of expended credit and advance same upon energization of the tapered resistor element residing in the device. Methods of employing this device in billing systems are also disclosed.
    Type: Grant
    Filed: December 3, 1976
    Date of Patent: August 1, 1978
    Assignee: Xerox Corporation
    Inventors: David D. Thornburg, Roy J. Lahr
  • Patent number: 4099999
    Abstract: A method of making a diode laser in which a pump current confining channel is formed on the substrate side of a diode laser prior to growth of the active or recombination region of the diode laser. The current confining channel is formed by providing, by diffusion, a rectifying junction on a substrate surface and then forming, by etching, a narrow channel completely through a central portion of the diffused layer and the rectifying junction. The remaining layers of the diode laser are then successively grown. The portions of the rectifying junction on both sides of the channel are reverse biased when the primary junction of the diode laser is forward biased whereby pump current flow is confined to a path through the channel.
    Type: Grant
    Filed: June 13, 1977
    Date of Patent: July 11, 1978
    Assignee: Xerox Corporation
    Inventors: Robert D. Burnham, Donald R. Scifres
  • Patent number: 4099071
    Abstract: A tapered resistor heating element is provided which sequentially heats and actuates in a controlled fashion heat sensitive media. In one embodiment a tapered resistor heating element sequentially heats in a controlled fashion heat sensitive switches. Heat sensitive resistors and heat sensitive threshold switches may also be employed in this configuration. This system may be utilized as a meter relay or as described in another embodiment as a scanner. Novel exclusive OR gates are also disclosed which are employed in one embodiment of the scanner of the instant invention.BACKGROUND OF THE INVENTIONThis invention relates generally to scanning devices and more specifically to monolithic electronic scanning devices.It is known that a major problem with matrix addressed displays and the like is the requirement for numerous connections in their implementation between the matrix elements and the ancillary addressing and driving devices. For instance, a display panel with 10.sup.6 matrix elements requires about 2.
    Type: Grant
    Filed: December 3, 1976
    Date of Patent: July 4, 1978
    Assignee: Xerox Corporation
    Inventor: David D. Thornburg
  • Patent number: 4056823
    Abstract: An analog chart recorder is provided having a heater assembly which includes a tapered, electrically resistive element that develops a non-uniform temperature profile on electrical energization along its length. A substrate is provided under the resistive film which is in thermal contact with the film. A heat sink in thermal contact with the substrate provides that the temperature distribution will achieve steady state. Means are provided for advancing a heat sensitive medium past and in contact with the heater assembly thus providing the analog chart recorder.
    Type: Grant
    Filed: December 3, 1976
    Date of Patent: November 1, 1977
    Assignee: Xerox Corporation
    Inventor: David D. Thornburg
  • Patent number: 4056822
    Abstract: A paper transport system used in connection with a thermal analog recorder is provided. This system engages the paper for a predetermined length of time and subsequently releases it employing mechanical means. Roller means are provided for engaging and transporting a heat sensitive paper. When the test paper is inserted into the nip formed between the roller means, a tapered resistor element residing on at least one of the rollers is made to develop a non-uniform temperature profile when energized from the output of a test source which permanently marks or records on the test paper. An improved method of single channel thermal analog recording is also disclosed employing this device.
    Type: Grant
    Filed: December 3, 1976
    Date of Patent: November 1, 1977
    Assignee: Xerox Corporation
    Inventors: David D. Thornburg, Geoffrey O. Thompson
  • Patent number: 4024534
    Abstract: A keyboard encoding system having a pause built into the repeat key function. A multi-stage counter has a first of its stages coupled to a first bistable switching device and another, higher order stage coupled to a second bistable switching device. When a repeat key is closed, the counter is incremented past the first stage to the higher order stage which renders the second bistable switching device conductive and, due to the interconnection between the switching devices, primes the first bistable switching device. When the counter again increments to the first stage, the first bistable switching device conducts to produce, after the pause provided by the system, a repeat key encoding signal.
    Type: Grant
    Filed: November 24, 1975
    Date of Patent: May 17, 1977
    Assignee: Xerox Corporation
    Inventor: Wilbur E. DuVall