Abstract: A high resolution raster display includes a central processor for providing image data, a digital image processing circuit for converting the image data to display signals, and an analog display circuit for converting the display signals to drive signals for driving a CRT to form a color raster display on the screen of the CRT. The digital image processing circuit includes a display memory for storing the image data and a programmable attribute look-up table for storing attribute data. Under the control of the central processor, the image data stored in the display memory is read out and is used to address the attribute look-up table which provides attribute signals as an output. A pixel rate converter reads in the attribute signals at a first rate and outputs analog display signals at a second rate which is much higher than the first rate, with a video bandwidth of up to 210 MHz.
Abstract: A multimode fiber optic coupler includes a first multimode optical fiber having a core and cladding surrounding the core and having a first longitudinal segment in which the cladding has been substantially removed exposing the core and in which a portion of the exposed core forms a first biconical taper segment; a second multimode optical fiber having a core and a cladding surrounding the core and having a second longitudinal segment in which the cladding has been substantially removed exposing the core and in which a portion of the exposed core forms a second biconical taper segment; and a coupling region formed by portions of the first and second biconical taper segments being fused together in parallel juxtaposition with one another.
Abstract: A method for removing excess solder from a printed circuit board is practiced by mixing a quantity of ceramic beads with an oil to form a fluidized bed mixture. The fluidized bed mixture is heated to a temperature above the melting point of a solder on the printed circuit board. A surface of the printed circuit board to be cleaned is placed in contact with the heated fluidized bed and agitated against the bed to remove excess solder.
Abstract: A decoder for recovering data signals and clock signals from an encoded data stream includes: a delay circuit responsive to an encoded data stream for producing a delayed data stream, the delayed data stream being delayed a predetermined period of time from the encoded data stream; a D-type flip-flop responsive to the encoded data stream and to a clock signal for producing a data signal; and a phase comparator responsive to the delayed data stream and to the data signal for producing a clock signal.
Abstract: A data transfer controller allows data to be transferred from a network bus to a system bus in a host computer. The controller has a network bus interface for communicating with the network bus and a system bus interface for communicating with the system bus. The system bus interface has first and second buffers. A dual port memory is utilized and has one port operatively connected to one of the buffers in the system bus interface and to a microprocessor. The direct access channel is established and operatively connected to the other buffer of the system bus interface as well as coupled to the microprocessor and associated control logic. A switch under control of the control logic establishes connections between the second port of the dual port memory and either the direct access channel or the network bus interface.
Abstract: A multiple layer connection system for compactly connecting a plurality of surface mount integrated circuit packages to a printed circuit board is disclosed. A plurality of staggered metal legs is respectively inserted into a plurality of slots formed along an edge of an intermediate plastic sheet. A first outside sheet and a second outside sheet sandwich the intermediate sheet between themselves. The first outside sheet has a plurality of foil conductors formed on an inside layer thereof to connect with a first portion of the staggered legs. A plurality of feed through holes are in electrical connection with the first conductive traces and with a plurality of first outside foil traces which are connectable by soldering to the legs of a surface mount integrated circuit package. A second plurality of inside foil traces is formed on an inside layer of the second plastic sheet and contacts a second group of the legs.
Abstract: A temperature compensated complementary metal-insulator-semiconductor oscillator receives a temperature independent reference voltage from an external source. The temperature independent reference voltage is attenuated and summed with a threshold voltage in order to bias a gate electrode of MOSFET. A bipolar p-n junction diode is connected to the MOSFET at a source electrode in order to bias the MOSFET with a temperature dependent forward voltage drop to compensate for temperature variations therein. The MOSFET controls a temperature independent current. A current mirror assembly receives the current and controls a Schmitt trigger oscillator. The Schmitt trigger oscillator generates a signal having a temperature independent constant period.
October 15, 1985
Date of Patent:
December 22, 1987
Babu L. Jain, Pardeep K. Jain, Michael S. Briner
Abstract: A circuit for measuring small propagation delays associated with a digital logic circuit has first and second signal paths. The first signal path in the digital logic circuit has at least a first predetermined number of devices and has an input and an output. Similarly, the second signal path in the digital logic circuit has at least a second predetermined number of devices and also has an input and an output. The first predetermined number of devices is different than the second predetermined number of devices. An input multiplexer multiplexes a predetermined input signal to the inputs of the first and second signal paths. First and second output signals are thereby produced on the outputs of the first and second signal paths, respectively. An output multiplexer causes the output signals to be combined into a single multiplexed output signal. An average propagation delay is determined from the differential area between the output signals in the multiplexed output signal.
Abstract: This disclosure depicts a novel semiconductor device and the method of making it. A novel field effect transistor (FET) has a channel region which is heavily doped under the gate and between the gate and the source of the FET. The channel region between the gate and the drain is lightly doped. The FET is formed on a heavily doped semiconductor substrate. The method of making the novel FET comprises providing a mask layer over a lightly doped channel region and forming openings in the mask layer such that a portion of the mask is located at the gate location and has a predetermined width and height. Ion implanting is performed at a predetermined angle such that a first portion of the channel adjacent the source is heavily doped and a second portion of the channel adjacent the drain is not exposed due to the height of the mask at the gate.
Abstract: A package for thermal dissipation of heat from multiple integrated circuit chips is described. The package includes a silicon substrate for electrical connection to silicon integrated-circuit chips. The silicon substrate provides a high degree of thermal dissipation of heat generated by the chips. In addition, the invention comprehends that the silicon substrate is attached to a heat dissipating means. In the preferred embodiment, the heat dissipating means includes a metal heat sink. The package is capable of dissipating up to six watts per square centimeter of heat from the chips.
Abstract: A solid state relay is responsive to a control signal and is used with an impedance load and a source of alternating electrical power. The solid state relay is used to connect and disconnect the load from the source of alternating electrical power. The solid state relay turns on in response to a control signal and to a substantially zero voltage crossing of the alternating electrical power of the source. The solid state relay turns off in response to the control signal and to a substantially zero current crossing of the alternating electrical power of the source.
Abstract: A protector device as described for enhancing the security of a computer system which includes one or more user terminals in one or more host computers. The protector device includes a detection means for monitoring communications between the terminals and the host computers in which the detection means is independent from the host computers in the terminal but is connected to the computers and terminals such that certain information transmitted between the computers and terminals is transmitted through the detection means. The detection means includes additional means for user authentication, access control, command filtering, audit trail recording, audit trail analysis, interrogation, and cryptographic services. The detection means further includes means for generating an alarm in the event that certain potentially sensitive events occur and means for interrogating events generated and stored in the detection means.
Abstract: A gallium arsenide differential line receiver circuit has a first and second receiver means for receiving first and second differential input signal voltages. A pair of depletion transistor means for transforming the signal voltages into corresponding signal currents provides pull-up, and the depletion transistors have their gates operatively connected to the first and second receiver means. A pair of enhancement transistor means is operatively connected to the pair of depletion transistor means for outputting a gallium arsenide signal representation of the first and second differential input signal voltages. Positive feedback is provided for increasing the gain of the pair of enhancement transistors and is operatively connected to the pair of enhancement transistors. Shunting means is also provided for reducing hysteresis switching and is operatively connected to the pair of enhancement transistors.
Abstract: An enhanced differential pair amplifier circuit 28, 30 is described which provides a linearity correction technique. The linearity correction technique is designed to compensate for nonlinearities in the base-to-emitter output voltage of each transistor in a differential pair of transistors over the dynamic input range of the amplifier. The present invention comprises the inclusion of compensation diodes or transistors 42, 44 in the load circuit of each input transistor in the differential pair to compensate for nonlinearities.
Abstract: An improved conduit (50) communicating between a pressurized source (10) of solution and a partially filled reservoir (34) associated with a drip chamber (24) in a continuous-flush system. The conduit comprises a tube (54,56) that is bent at approximately a 45 degree angle so that solution discharging from the conduit (50) is diverted to impinge against the interior wall (58) of the reservoir (34) before interfacing with the solution (62) accumulated therein. The arrangement reduces bubble formation normally associated with turbulent discharge flow during filling and flushing of the system.
Abstract: A variable control device comprises a manually operable member (5) arranged to be moved in a first direction (A) by an operator. A substrate (2) is provided with a plurality of contacts (4) spaced apart in a plane transverse to the first direction. A further member (6) is disposed between the manually operable portion (5) and substrate (2), The further member (6) is provided with a conductive surface facing the substrate (2). Movement of the manually operable portion (5) in the first direction (A) causes deformation of the further member (6). Contacts 4 on the substrate are progressively bridged by the further member conductive surface as deformation of the further member (6) increases.
Abstract: A method for repairing clear defects on a photomask. The method includes the steps of coating the photomask with a positive photoresist; exposing the photoresist to a laser beam for localized heating thereof to a temperature above 500.degree. C. to darken or char the polymer; and removing the unexposed polymer from the photomask. The method may also include the intermediate step of heating the polymer to a temperature between 200.degree. C. and 500.degree. C. to brown the polymer before the polymer is exposed to the laser which heats it to a temperature above 500.degree. C.
June 20, 1984
Date of Patent:
June 3, 1986
Peter L. Young, Modest M. Oprysko, Mark W. Beranek
Abstract: A pressure sensor includes a diaphragm and an overpressure stop, with a gap inbetween for displacement of the diaphragm in response to an applied pressure, the diaphragm being formed of laser-recrystallized polysilicon. Data extraction is accomplished either by depositing or forming four piezoresistors on the diaphragm and connecting them as the elements of a Wheatstone bridge circuit or by using the appropriately doped laser-recrystallized diaphragm as a piezoresistor itself.
Abstract: A method for intermetallic diffusion bonding of piezoelectric components, wherein ceramic pieces with fired-on silver electrodes are stacked with a thin shim of solid indium alloy therebetween. The indium alloy preferably comprises 25% indium, 37.5% lead and 37.5% tin. The stack is placed under 150 psi compression and heated at a temperature of about 350.degree. for 30-48 hours in an inert gas. Almost immediately upon being heated, a liquid-solid diffusion takes place in which a small amount of the silver diffuses from the electrodes into the now liquid indium alloy. The alloy in the interface becomes saturated with silver producing a new quaternary alloy which has a higher melting point than the previous indium alloy shim. Thus, there is a gradual solidification of the alloy as the concentration of silver increases. After solidification of the new alloy during the remainder of the heating time, there is a gradual diffusion of the indium into the silver and vice versa.