Patents Represented by Attorney, Agent or Law Firm Barry N. Young
  • Patent number: 5178476
    Abstract: A carriage is displaceable parallel to a record carrier and supports a head displaceable in a direction essentially perpendicular to the record carrier. In order to obtain a mounting free of play while maintaining parallelism of the head during its movement and at the same time reduce the risk of damage to the head in the event of a collision, the head is supported by at least one leaf spring pair. Each leaf spring pair consists of a front and a rear leaf spring attached between the carriage and the head in attachment points. The connecting lines between the attachment points of the leaf springs substantially form a parallelogram. The apparatus is used as a printer for printing information on record carriers of paper type.
    Type: Grant
    Filed: January 30, 1991
    Date of Patent: January 12, 1993
    Assignee: Digital Equipment Corporation
    Inventor: Ernst C. G. Lindelow
  • Patent number: 5177555
    Abstract: A method and apparatus for optically determining the distribution of normal force present at the mating surfaces of an electrical surface connector uses the birefringent properties of a photoelastic material. Photoelastic members are distributed between the two planar surfaces, and plane-polarized, narrow-band wave-length light is coupled into each member with an optical fiber. The light is directed to propagate along a principle strain axis of the photoelastic member. The temporarily birefringent photoelastic material provides a relative propagation delay between vector components of the light in each member which are perpendicular to the propagation direction. The light exiting each member is input to a plane polarizer, the output of which is measured with an intensity meter. The relative delay between the vector components creates a detectable change in intensity at the intensity meter.
    Type: Grant
    Filed: March 28, 1991
    Date of Patent: January 5, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Mark D. Stratton, Terri G. Laird
  • Patent number: 5175410
    Abstract: The present invention involves a hold-down fixture which is usable in connection with bonding an integrated circuit package to a printed circuit board in a surface mount environment. The purpose of the fixture is to hold each of the leads of the package in intimate contact with corresponding contact pads on the printed circuit board during the bonding process. The fixture includes a base with two bars for each group of leads extending from the perimeter of the housing of the package. Together the bars compressively force the entire foot of each lead to set flatly against its pad. The bars are spaced such that an aperture, which is defined by an opening through the base and positioned between the bars, can admit a bonding means, such as a laser beam, to reflow a solder composition at the lead/pad junction. Accordingly, with the leads compressed against the pads by the bars of the fixture, and with the reflow of the solder composition by means of the laser, a good bond between each lead and pad will be formed.
    Type: Grant
    Filed: June 28, 1991
    Date of Patent: December 29, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Gary M. Freedman, Maurice P. Brodeur, Peter J. Elmgren
  • Patent number: 5175814
    Abstract: A method and apparatus that translates a natural language query into a Boolean expression to be used to search a database. The Boolean expression is displayed on a screen so that the user can alter the Boolean expression using a mouse or similar input device and re-execute the search. The manipulations performed by the user include moving terms of the query, changing the order in which query terms are evaluated, adding terms, deleting terms, and selecting alternate versions of terms.
    Type: Grant
    Filed: January 30, 1990
    Date of Patent: December 29, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Peter G. Anick, Jeffrey D. Brennan, Rex A. Flynn, Bryan Alvey, David R. Hanssen, Jeffrey M. Robbins
  • Patent number: 5175613
    Abstract: A package for integrated circuit chips, or other electrical devices, provides mechanical shock and thermal protection for the chips, and in addition, protects the chips from electromagnetic interference and electrostatic discharge. The package includes a printed wiring board base for reception of one or more circuit chips, and a conductive heat sink and cover. The conductive heat sink, in conjunction with a reference plane in the wiring board base, acts as an EMI shield for the chips. The heat sink is covered with an insulating layer, on top of which, a conductive coating is placed. The conductive coating is electrically connected to the reference plane, and the two act to protect the chips from electrostatic discharges. Compliant pads support the chips, and a thermally conductive elastomer can be placed on top of each chip between the chips and the inner top surface of the heat sink. The chips are thereby held securely in position, and are thermally connected to the heat sink.
    Type: Grant
    Filed: January 18, 1991
    Date of Patent: December 29, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Charles R. Barker, III, Richard J. Casabona, David M. Fenwick
  • Patent number: 5175488
    Abstract: A master bias voltage regulator circuit (5) has an output node for supplying a temperature compensated reference voltage (VREF1) to an input node of at least one slave ECL bias regulator circuit (4). The temperature compensated reference voltage is also compensated for a temperature-related characteristic of at least one ECL load, such as an ECL gate (2), and is also compensated for a temperature-related characteristic of the at least one slave ECL bias regulator circuit. VREF1 is sourced from an emitter of an output transistor (5Q7) and the collector of the output transistor is coupled to the emitter of a matching transistor. This technique is shown to provide improvements, relative to the prior art, in output reference voltage stability over variations in power supply voltage, temperature and process variations, while also reducing power consumption.
    Type: Grant
    Filed: May 10, 1991
    Date of Patent: December 29, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Andrew P. Moroney
  • Patent number: 5172922
    Abstract: This invention relates to a self aligning, vacuum end effector which is capable of picking up objects which have a pick up surface which is not planar with the pick up surface of the end effector. The end effector is comprised of two parts: a nozzle base which fixedly attaches to an automatic assembly device, such as robotic arm; and a nozzle tip, which is the part of the end effector which actually comes in contact with the object to be picked up. The nozzle base and nozzle tip are secured together by a retention spring. The nozzle tip has a generally, semi-spherically shaped ball portion which is partly inserted into a bore within the nozzle base and rests against a quad ring which is secured within the bore. Consequently, when the nozzle tip makes contact with an object which is to be picked up and moved, the semi-spherical ball portion of the nozzle tip slides against the quad ring and the nozzle tip pivotally moves and aligns itself with the plane of the surface of the object to be picked up.
    Type: Grant
    Filed: April 25, 1991
    Date of Patent: December 22, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Kelli L. Kowaleski, Yuen-Foo M. Kou, Gary D. Roberts
  • Patent number: 5173853
    Abstract: A style of document format known as compound document architecture is known, in which a document is broken up into a tree of objects or segments (e.g. document: chapter: subtitle: para: para: etc.), possible with a second layout tree. Two styles of such architecture are ODA and CDA. Conversion from CDA to ODA presents difficulties, as in CDA, a segment can contain e.g. text and graphic elements, while ODA has stricter formatting rules. One of a plurality of DAPs (Document Application Profiles) 12 is selected, depending on which subset of full ODA is being used. The DAP contains a structure converter component which starts to construct the objects of the ODA document. When an information element is reached (text, graphics, etc.), it is sent to the appropriate one of a set of content handlers 13. These call back to callback units (text, graphics, footnote, etc.
    Type: Grant
    Filed: March 14, 1991
    Date of Patent: December 22, 1992
    Assignee: Digital Equipment International Ltd.
    Inventors: Jean Kelly, Paul McNelis, J. Mark Smith
  • Patent number: 5172755
    Abstract: An arcuate profiled heatsink is disclosed, over which is flexed and attached a substrate on which are mounted heat producing, temperature sensitive electronic devices. Flexing the substrate to conform with the arcuate surface of the heatsink minimizes air pockets between the two, which would ordinarily result due to warpage resulting from the fabrication of the substrate. The interface between heatsink and substrate, therefore, has lower thermal resistance, thus, increasing thermal conductivity between heatsink and substrate, and increasing the amount of heat dissipated by the heatsink. Because no hard joining of the two parts is required, they may be separated for repair, and stress resulting from thermal expansion mismatch will not be transferred to the substrate.
    Type: Grant
    Filed: April 1, 1992
    Date of Patent: December 22, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Victor M. Samarov
  • Patent number: 5170403
    Abstract: A laser diode modulation circuit for grayscale laser printing provides variable control for both the current through the laser diode and the modulation (switching) of the diode in time. The size of a printed area within a pixel region is determined in two dimensions by the power output of the laser diode and the modulation of the laser diode within the pixel region. The power output of the laser diode is detected with a photodiode detector which is part of a feedback loop for adjusting the maximum bias current value of the diode. The maximum bias current value is held as a digital value with a digital counter, and is adjusted by incrementing or decrementing the counter. A drive current for the laser diode is selected for each pixel as a percentage of the maximum bias current value using an analog multiplexer. A modulation signal is generated in response to modulation information received, and controls the switching of the laser diode within a pixel region.
    Type: Grant
    Filed: May 31, 1991
    Date of Patent: December 8, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Christopher M. Mayer
  • Patent number: 5168919
    Abstract: An air-cooled self-contained evaporator and condenser apparatus with no external power source, the apparatus including a cold plate having a first surface with recesses formed therein in a matrix or array corresponding to the matrix or array of chips on a multi-chip module or unit. The opposite surface of the cold plate includes a finned arrangement which, in conjunction with the cold plate, forms part of an isolated evaporation chamber of the cooling unit, with the chamber housing a boilable fluid which changes phase from liquid to vapor. Positioned above and contiguous with the isolated chamber is a condensing chamber, including a plurality of tubular passageways, the external portions of which are finned for ready removal of heat. For attachment of the cold plate portion of the unit to the chips, suitable heat transfer slugs, such as aluminum nitride slugs, are affixed in the recesses, with opposites surfaces thereof bonded to the exposed faces of the chips.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: December 8, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Jack Berenholz, John K. Bowman
  • Patent number: 5163551
    Abstract: This invention relates to a carrier for transporting integrated circuit devices. In particular, the carrier is configured to cradle devices which have preformed leads which usually extend around the perimeter of the device and tend to be fairly fragile. The carrier is made up of a carrier top and a carrier bottom, which are securely closed through the attachment of several spring clamps. The bottom provides a secure nest which is configured to the shape of the body of the device. The top includes a hold-down member which houses two rings, a compression ring and a contact ring, within a channel. The compression ring is made of a rubber like material that can elastically compress under contact pressure, while the contact ring is made of a hard material, which will not stick to the top of the device. The contact ring, which is positioned between the compression ring and the device, engages the device when the carrier top and the carrier bottom are mated.
    Type: Grant
    Filed: June 28, 1991
    Date of Patent: November 17, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Ram D. Bhatia
  • Patent number: 5161193
    Abstract: Cryptographic apparatus, and a related method for its operation, for in-line encryption and decryption of data packets transmitted in a communication network. A full-duplex cryptographic processor is positioned between two in-line processing entities of a network architecture. For example, in a fiber distributed data interface (FDDI) network, the processor is positioned between a media access control (MAC) sublayer and a ring memory controller (RMC). Incoming information packets are analyzed to decide whether or not they contain encrypted data and, if they do, are subject to decryption before forwarding. Outbound information packets have their data portions encrypted if called for, and are usually forwarded toward the network communication medium. Cryptographic processing in both directions is performed in real time as each packet is streamed through the processor.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: November 3, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Butler W. Lampson, William R. Hawe, Amar Gupta, Barry A. Spinney
  • Patent number: 5158912
    Abstract: An injection molded aluminum nitride heatsink forms the substrate of an integral heatsink semiconductor package in which a semiconductor chip is attached directly to the integrated heatsink forming an intimate thermal relationship between the heat generating source and the heat dissipating means. In a first embodiment, a planar surface of the heatsink component provides the substrate for the attachment of a semiconductor chip and a multilayer housing formed from a plurality of layers of dielectric glass ceramic lamina and conductive circuit layers. The multilayer housing is formed on top of the heatsink substrate creating a recessed cavity in which the semiconductor die sits and is attached directly to the heatsink. The semiconductor chip is attached to the circuit layers of the housing through any of the known electrical connection methods, such as wirebonding or tab tape. A cover plate is mounted over the cavity.
    Type: Grant
    Filed: April 9, 1991
    Date of Patent: October 27, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Dave Kellerman, Robert J. Hannemann, Stanley J. Czerepak, Robert J. Simcoe
  • Patent number: 5156371
    Abstract: A triaxially-equalized action shock and vibration-insulation mount is provided for the protection of a dynamic load-sensitive component, such as a mass-storage device, from external multidirectional dynamic loads above a predetermined magnitude. A substantially uniform, attenuated response of the component to such dynamic loads is the result, regardless of the direction of application of the loads. In order to achieve substantially uniform reactions to such external loads applied along any of the three orthogonal spatial axes, and further in order to achieve higher structural integrity of the mount by reducing flexural, tensile and/or shear stresses, the shock mount comprises a body of elastic, preferably foamed elastomer material, which is confined at its periphery in a rigid, stationary shell, substantially symmetrical relative to the orthogonal spatial axes and partially open at one side. The elastic material body is shaped at its geometrical center to provide a tight, e.g.
    Type: Grant
    Filed: June 20, 1991
    Date of Patent: October 20, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Victor M. Samarov
  • Patent number: 5157673
    Abstract: A masking comparison circuit outputs a signal "non-correspondence" if two binary signals received are unequal. However, there are provided masking means for masking this non-correspondence signal unless both binary signals for some time have been stable and, moreover, different. A comparison circuit of this kind forms part of, for example a data processing device based on redundancy.
    Type: Grant
    Filed: March 7, 1990
    Date of Patent: October 20, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Fredericus H. J. Feldbrugge
  • Patent number: 5153794
    Abstract: An assembly and method for securing head suspension members on shelf segments of metallic or ceramic actuator arms in a disk drive. The assembly comprises an actuator arm with a reduced thickness shelf segment, at least one head suspension member, a staking member having particular attributes and a staking plate also having particular attributes. The assembly is designed such that forcible expansion of the staking member takes place exclusively within the material of the staking plate member. The method is formulated such that the constituent elements of the assembly are aligned, placed under compression and staked together wherein an interference fit is formed between the staking member and staking plate member and no forcible pressure from the staking procedure is transmitted to the actuator arm. The assembly and method are ideally utilized in a multi-disk disk drive in which a plurality of head suspensions are secured to multiple arms of a single actuator in a single procedure.
    Type: Grant
    Filed: December 7, 1990
    Date of Patent: October 6, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Sigmund Hinlein
  • Patent number: 5150360
    Abstract: A method and related apparatus for establishing a point-to-point cross-link between two bridges in a bridged communication network. The bridged communication network is first configured in a loop-free arrangement by a spanning tree algorithm that selects which links of every bridge to activate in order to form the spanning tree active configuration. Then at least one cross-link not defined by the spanning tree configuration is established for routing of messages as an alternative to a spanning tree path. A protocol in each bridge ensures that no loops are formed and that only messages to preselected locations are passed over the cross-link. An optional optimization procedure measures message propagation times in both directions between the two bridges and over both the cross-link path and the spanning tree path, to determine whether to modify usage of the cross-link.
    Type: Grant
    Filed: March 7, 1990
    Date of Patent: September 22, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Radia J. Perlman, William Hawe, Anthony Lauck
  • Patent number: 5149210
    Abstract: A recording and/or reading head has a recording and/or read nose and is movably mounted. The head is preloaded against a record carrier with first and second preload values. A sensor device senses and maintains the distance between the record carrier and the nose constant. The preloading structure includes a spring loaded cam operated mechanism acting between the head and the record carrier via a spring loaded wheel secured to the head, the wheel engaging the record carrier. A switching mechanism switches the apparatus between the first and second preload conditions. The apparatus can print or operate with documents of different thicknesses.
    Type: Grant
    Filed: January 30, 1991
    Date of Patent: September 22, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Bjorn S. H. Eriksson
  • Patent number: 5148969
    Abstract: This invention relates to an apparatus and method by which electronic components can be reclaimed from printed circuit boards. In the preferred embodiment, the reclamation system includes a conveyor which grasps the edges of the boards and holds them at an angle so that the component sides of the boards are facing downward. The conveyor carries the boards past infrared panels which heat each board, so that the solder bonding the components to a given board is made to reflow. While the solder is in a reflow state, each board is struck with a tapper, the impact of which has a tendency to dislodge the components. Falling components are caught in bins where they can be collected. In addition, the reclamation system is configured such that a number of operators are able to work in front of the boards passing on the conveyor. Therefore, if the tapper fails to dislodge any components on a given board, an operator can manually remove the components before the board is itself removed from the conveyor.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: September 22, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Bernard J. Boucher, Kerry S. Dinsmore, John A. Malesky, Douglas A. Brochu