Abstract: A method for controlling the operation of a brushless DC fan for cooling heat generating components of a system is provided. The method includes providing a system temperature signal indicative of a system temperature and providing an intelligent shutdown enable signal. The system temperature signal is compared with a shutdown temperature signal if the intelligent shutdown enable signal has a first value. The shutdown temperature signal is representative of a shutdown temperature value. The fan is operated at a generally temperature proportional speed after comparing the system temperature signal with the shutdown temperature signal if the system temperature as indicated by the system temperature signal is greater than the shutdown temperature value as indicated by the shutdown temperature signal.

Abstract: A heat sink for an arc lamp comprises a thin-wall copper strip that is brazed in pleated folds between inner and outer cylindrical rings to create cooling fins. The thickness of the material used for the cooling fins can therefore be exceedingly thin, e.g., 0.012 inches. The cylindrical rings act as fin supports and provide mechanical sturdiness. The thinness of the fin material allows a large number of fins to be included and the efficiency is increased thereby.

Abstract: An electronic distance meter comprises an integrated circuit from a GPS navigation receiver having a local pseudo-random number code generator for code demodulation that is connected to modulate either a polychromatic or a monochromatic light source. An optical system focuses the light on a distant target with an unknown range. Reflections from the distant target are focused on a light detector that produces a phase-delayed copy of the original pseudo-random number code. The time-of-flight to and back from the distant target is a function of the distance. The GPS receiver integrated circuit computes the range based on the code-phase delay to a precision better than one centimeter. The position of a remote target can be triangulated from several electronic distance meters each having known positions, e.g., determined by included GPS navigation receivers.

Abstract: A mechanical linkage within a computer disk drive is used to ensure that the disk drive heads are parked prior to diskette ejection. An eject frame moves with respect to the chassis and drives a latch in an arcuate path. The latch engages an actuator and drives the actuator to an inner diameter position. The mechanical linkage ensures that the actuator is captured in its parked position whenever the eject frame is in an ejected position. The latch is returned to a stowed position when a diskette is installed in the disk drive. The mechanical linkage protects the heads by ensuring proper clearances from the diskette, and by positioning the actuator in a structurally rigid portion of the receiver plate. The invention has particular applicability to disk drives for portable computers.

Abstract: A processor is connected to a display screen to generate a screen display of individual characters in groups together with the selector indication. Such characters typically belong in a language set, e.g., English, Japanese, Greek, etc. The processor receives from the numeric keypad a user selection of a number "1-9" that is associated with a particular one of the individual characters in a group highlighted by the selector indication. An index-and-fetch mechanism, typically implemented as a computer program sub-routine, provides for an indexed fetch of a digital data representation in a font memory of a character indexed according to the number "1-9". The fetched digital data is then available for more general use by a larger computer system, for example in the form of an "ASCII" output character.

Abstract: A sand/liquid separator provides for the conditioning of oil sands. Clean sand is separated from the ore and discharged for use as backfill. The sand/liquid separator machine includes horizontal shafts with paddles that act on a fluidized bed. The overall height of the machine is increased over prior art devices so the water volume is expanded. For a given residence time, more sand can be separated out than is otherwise possible. The water-to-sand ratio is an independent variable, water is recycled independent of the sand. The rate of water recycle depends only on the heat input needed and the clay content of the feed. The rate of water input is limited by the rise velocity needed to separate sand larger than forty-four micron from the water/liquid phase. This, in turn, determines the maximum oil sand feed rate based on the total clay in the feed at up to six percent, by weight, of clay in the middlings in the machine.

Abstract: A primary color lamp comprises a glass envelope with a krypton arc doped with metal halides. A cesium bromide or cesium iodide solution is included with lithium iodide (LiI) to produce red light, thallium iodide (TlI) to produce green light and indium iodide (InI) to produce blue light. The solution controls the vapor pressures of the lithium iodide (LiI), thallium iodide (TlI) and indium iodide (InI) and allows them to be balanced for light amplitude output. No mercury is used in order to eliminate a corresponding yellow light output and the filter complications that result in a system that operates on the primary colors.

Abstract: The present invention includes a method for automatically reconstructing most of the power, ground and clock prerouting without significant user involvement. This enables several floorplans to be tried concurrently in a batch mode. The method automatically migrates many floorplans in increments to find the best result for each starting floorplan. The user is then free to select a floorplan that looks best from the candidates generated with all the special net routing patterns already considered and updated for each.

Abstract: A process for extraction of alumina from ore bodies containing aluminum is disclosed. The process comprises the steps of acid leaching an aluminum bearing ore to produce a leach liquor that includes aluminum values and silicon values. Any ferrous sulfate in the leach liquor is oxidized with an oxidizing agent comprising ozone to ferric sulfate. The oxidized leach liquor is hydrolyzed at about 130.degree. C. to form a gel of ferric values which are then removed. Any ferric sulfate remaining in the leach liquor after hydrolyzing is reduced to ferrous sulfate. The reduced leach liquor is then hydrolyzed at 165-180.degree. C. to remove precipitated basic aluminum alkali sulfate. The basic aluminum alkali sulfate is then dried and calcined at around 950.degree. C. to produce alumina and alkali sulfate which releases any SO.sub.2 and any SO.sub.3. The alumina is washed to remove any alkali sulfate and the washed alumina is then agglomerated and dried.

Abstract: A computer-automation tool for dentists and insurance companies to communicate dental patient information is provided. Such system has a specialized PC-peripheral that produces digital images from transparency films and dental intra-oral intra-oral radiographs, e.g., x-ray films, for storage, retrieval, viewing, transmission, and processing on computer networks. For example, dental intra-oral radiograph images can be captured at a local dentist's office and transmitted over the internet to support quick insurance claim processing. The digitizer peripheral is automatic enough that no special skills beyond that of an office clerk are required. To digitize an x-ray film frame, the film is simply dropped into a slot on the digitizer peripheral. No menu items or key needs to be selected on the computer. The sensing of the film insertion, its positioning, and releasing it after digitization are all automatic.

Abstract: A cartridge-filter cleaning spinner comprises a handheld spindle rod that can accommodate a variety of filter sizes. The spindle rod has two inward pointing slip-ring hand-tightened hubs. A cartridge filter is loaded on the spindle rod by removing one of the slip-ring hand-tightened hubs, slipping the cartridge filter onto the spindle snug against the other slip-ring hand-tightened hub, and then reinstalling the first slip-ring hand-tightened hub on the spindle rod. The cartridge filter is then free to spin around while the spindle rod handles themselves remain stationary. A water jet from a garden hose is then directed at one end of the cartridge filter to one side so the cartridge filter begins spinning. The water jet is then worked down slowly to the opposite end while keeping the spinning action going. The process is then repeated, but with the water jet directed to the other side so the cartridge filter spins in the opposite direction.

Abstract: An on-the-fly error detection and correction hardware core for a mass storage hard disk drive comprises a microcode machine optimized and limited to doing Galois Field arithmetic (GF[2.sub.8 ]) in support of Reed-Solomon error detection and correction (RS-EDC). The microcode machine is implemented as a hardware core in a system-on-a-chip design that includes a general purpose core RISC-processor. A dual-input arithmetic logic unit (ALU) includes a set of basic arithmetic blocks necessary to support the RS-EDC operations, i.e., a multiplier, a dedicated adder, a general purpose adder, a divider, a log unit, a quadratic solution lookup, a cubic solution lookup, and a move datapath. The operations and outputs of all the basic arithmetic blocks are presented in parallel to an op-code selector. The selected output is routed back for deposit to one of eight general purpose registers (R0-R7).

Abstract: A battery-operated navigation satellite receiver with an antenna, a radio frequency stage, a down-converter, a digital signal processor and a microcomputer for demodulating L-band microwave carrier frequency spread spectrum transmissions from orbiting navigation satellites that each use their own unique pseudo-random number spreading code. The digital signal processor and a microcomputer each receive system clocks that can be varied in steps from full-speed down to any number of fractions including zero, or full stop. The system clocks to the digital signal processor and a microcomputer are lowered during periods of little or no acquisition or navigation activity. Scheduled updates, communication traffic, user activity, etc., are used to ramp the system clocks back up when the processing load demands it, e.g., when the tasks become CPU-bound at the current clock speed or when a particular task is predetermined to need the full processing speed capability of a particular navigation receiver.

Abstract: A position sensor and a method of creating the same which sensor has an incoherent light source, multiple light detectors and a sinusoidal pattern that can be directly installed to the sensor. The light source and detectors are positioned along the axis of motion of the element whose position is to be determined. In a device containing such a movable target element, light from the sensor is directed through the sinusoidal pattern to and reflected from a periodic reflection profile to create detectable sinusoid signals that can be used for positioning purposes.

Abstract: A method for obtaining integer ambiguity solutions based on externally provided constraints, e.g., altitude. Such constraints are useful in reducing the computational burden created by the search problem, and using constraints is particularly more effective when a more limited number of satellite vehicles are visible than is ordinarily the case. The constraints are exercised in a search algorithm. As the branches of the integer ambiguity search tree are traversed, an additional test is used to determine if the current search candidate is compatible with such external constraint. Because a three-dimensional position is associated with each search candidate, the branch clipping is straightforward. The ambiguity candidates are each only acceptable if their locations in space are within a confidence region bound set determined from the external constraint.

Abstract: A pulsed high energy arc-tube flashlamp comprises a quartz flashlamp envelope that is about 2000 mm long and has an outside diameter of approximately forty-eight mm. Each end necks down to an outside diameter of about thirty-eight mm to accommodate an anode re-entrant seal assembly at one end and a cathode re-entrant seal assembly at the other end. Each anode and cathode comprises a beaded electrode rod of tungsten with an unusually large 0.25 inch diameter. A reflective metal paint or white oxide paint is added to the end necks to improve the lamp starting characteristics and to protect the cassette mounting o-ring and lamp cable junction box from radiation. A TEFLON shrink sleeve is shrunk over each outside end of the flashlamp envelope and such provides a small amount of cushion for the lamp mounts in the laser cassette. The monocoque body structure does not need separate lamp mounting bases, and thus overall provides a mechanically simpler and superior structure that is far more reliable.

Abstract: An incoming audio analog signal is sampled at a Nyquist criterion rate. The particular analog value sampled at each period causes one of a suite of programming algorithms to be selected and applied to a particular EEPROM memory cell. For example, there can be 256 different programming algorithms in the suite that open-loop result in a zero to full range analog multi-state data being recorded in each memory cell. The programming algorithms can vary the programming pulse heights, pulse widths and number of pulses applied to the selected memory cell. For a corrected readback, each or a representative spread of programming algorithms are "test-fired" at corresponding reference memory cells to establish a calibrator scale customized for each whole EEPROM device. The readback mechanism compares the multi-state data returned from analog sensing each memory cell to the reference memory cell calibration values to find a match.

Abstract: A GPS antenna comprises an antenna body that can rotate between horizontal and vertical positions between the handle horns on the top of an optical total station. A GPS receiver embodiment comprises an integrated body and antenna that can similarly be rotated between horizontal and vertical positions between the handle horns on the top of an optical total station to avoid interference with the total station optics.

Abstract: A video cassette recorder includes a tape transport and servo that records digital data at one tape speed and plays back the digital data at one twentieth of the recording speed, both with a fixed speed of rotation of a drum head. On playback, each recorded segment of data on the tape is read from ten slightly different longitudinal positions on the magnetic tape, with the highest amplitude read-back signal being selected. The drum head comprises two playback heads that each have playback widths that are approximately twice as wide as each of four recording heads in the drum head.