Abstract: This invention provides a method and apparatus for accurately measuring the flying height of a magnetic head at high speed by using a white lamp and a color CCD camera. The invention entails substituting tentative refraction coefficients and extinction coefficients representative of colors in theoretical equations expressing the relationship between interference light intensity and flying height, thereby optimizing the parameters by non-linear regression. The flying height of a magnetic head is measured by using the coefficient thus determined. Also, this invention enables determination of flying height at very high speed through effecting the above optimization in consideration of constants associated with the shape of the head under consideration, and adapting the above theoretical equations.

Abstract: Described is a network addressing scheme in which a message sent from a source node to a destination node includes a path address which defines the path over which the message should travel to reach the destination node. At each node along the path between the source and destination, the path address is compared against a predetermined value, and on determining that the address and predetermined value are different, the node modifies the address before forwarding the message onto the next node. In a switch node having three or more ports, the identity of the output port is determined from the path address and a portion of the address is deleted before sending the message out on that output port. Also described is a method of configuring a network in which one or more initiator nodes are defined, the initiator nodes issuing query messages to an adjacent node which responds by sending the initiator details of the number of operational ports which are implemented in the adjacent node.

Abstract: A computer-based system and method is provided for positioning a cutter tool to an edge of a solid model in a computer aided manufacturing environment. A shortest distance and direction required to position the machine tool cutter to the edge of the solid model is determined. Edges are defined as three dimensional space curves. The machine tool cutter is defined as a convex envelope. Using the space curve definition, the cutter location, and the center axis of rotation for the cutter, computations are executed to determine a directional vector and distance such that moving the cutter along the vector for the prescribed distance will cause it to be in contact with the curve. Adjustments are available which cause the cutter to travel to offsets from the curve, including aligning the front of the cutter to the curve, the end of the cutter on the curve, or the back of the cutter past the curve.

Abstract: Manipulation of distributed heterogeneous data in a data processing system having multiple diverse data sources is permitted by providing a global data directory which maps the location of data, specific data entity attributes and data source parameters. An attribute table is provided within the global data directory which sets forth desired attributes in a logical data model for each data entity within the data processing system. A domain table related to the attribute table is utilized to specify domain information for each data entity attribute. Route and cross-reference tables are provided and utilized to specify data source or database parameters and a cross-reference between logical names within the logical data model and the diverse data sources. Desired heterogeneous data is then accessed utilizing the route and cross-reference tables and converted utilizing any known technique into an output having the desired attributes set forth within the attribute table.

Abstract: An apparatus and method are provided for disabling the clocking of a processor in a battery operated computer during non-processing times. The clocking is disabled at the conclusion of a processing operation. The clocking can then be re-enabled using interrupts from any one of a plurality of sources, such as an I/O device or a direct memory access. Application programs and operating system programs running on the system can specify the stopping of the system clock and the central processor until a specified event which had been requested occurs, or until an optional time-out period has expired. In this situation, the event is defined as one that results in either a system interrupt from an I/O device or from a direct memory access operation. The stopping of the system clock is a two part operation wherein in the first part the stopping mechanism is first armed. If an interrupt is received subsequent to arming, then it will be processed and the arming mechanism will be reset.

Abstract: In a signal processing environment, voice messages are stored into and read out of a buffer in real time. Since voice messages are being stored and read from the buffer, different sizes and rates of information are being stored therein. Small packets of digitized voice are input to the buffer at a very high rate, while larger packets of data are output from the buffer at a lower rate and can be stored into permanent memory. The buffering of this digitized voice data occurs in real time using a ringed buffer. The transfer of data into and out of the buffer is under the control of a software application running on a host processing system. The producer of the digitized voice data is a signal processing system which converts an input analog voice signal into a compressed digitized signal. The consumer of the buffered digitized voice data is a software application program which removes blocks of multiple data records from the buffer for program execution.

Abstract: Operation of an AC plasma display panel requires the three control operations of write, erase, and sustain. Sustain, write and erase signals are stored in a plurality of sections in a storage device and the sections are selectively accessed according to the specific operation to be provided to the plasma panel display. The control signals stored within a given sequence are selected so that no dimming occurs during write and erase operations. A brightness control is provided to modulate the average repetition rate of signals applied to the plasma display panel. In this manner, a plurality of flicker-free brightness levels may be chosen.

Abstract: A driving system for a plasma panel display which uses VFETs for output switches controls the transition time of an output waveform to a constant time. Transformerless circuitry for communicating low voltage digital logic signals across a floating boundary to VFET control circuitry is provided. Low voltage control circuitry is isolated from high voltage sources by semiconductor circuitry which eliminates the need for transformer isolation techniques. In an alternative embodiment, the transition of an output waveform is controlled at a constant slew rate.

Abstract: Method and apparatus for automatic optical inspection of a substantially two-dimensional pattern using digital image processing techniques are described. In a first processing step, all regions of a digitized stored image derived from the two-dimensional pattern are scanned for edges or lines, that is, transitions between regions having optically different characteristics. The scanned edge regions are marked in the image storage. In a subsequent second processing step all non-marked regions of the image storage are scanned and tested for the presence of permissible grey levels. A meander-shaped scanning track is used for scanning the edge or lined regions. The apparatus for implementing this method includes special latch circuitry for eliminating the further processing of marked regions, thus increasing the overall speed at which the two-dimensional pattern can be optically inspected.

Abstract: A method for etching a batch of semiconductor wafers to end point using optical emission spectroscopy is described. The method is applicable to any form of dry plasma etching which produces an emission species capable of being monitored. In a preferred embodiment, as well as a first alternative embodiment, a computer simulation is performed using an algorithm describing the concentration of the monitored etch species within the etching chamber as a function of time. The simulation produces a time period for continuing the etching process past a detected time while monitoring the intensity of emission of the etch species. In a second alternative embodiment, this latter time period is calculated using mathematical distributions describing the parameters of the etching process. In all three embodiments, the actual time that end point of an etching process is reached is closely approximated.

Abstract: A central clock signal generator generates a plurality of odd and even clock pulses which are distributed to a plurality of logic and circuit modules by clock signal lines of equal length. The central signal generator also generates a plurality of gate pulses which are supplied to the modules on signal lines which can be different in length from one to another. The gate pulses are wide enough to coincide with the clock pulses with appropriate allowance for skew between the pulses. For each pair of pulses engaged delivered to a module a detection circuit is provided which detects if the gate pulse and the clock pulse begin and end in the proper sequence. If an improper sequence occurs, the information is stored in a scannable latch and a machine stop control is generated. The exact failing module can be traced readily from the information supplied in this manner.

Abstract: A method of making a plurality of multi-wire nonimpact printheads provides precise inter-wire spacing accuracy and repeatability of manufacturing steps to enable mass production.A plurality of slats are molded, one alongside another on a cylindrical support shell, parallel to the shell axis. A helical thread is engraved on the slats along the axial length of the support shell. A continuous wire is wrapped in the thread and the portions of the wire on the slats are encapsulated. The support shell and wrapped wire is cut between adjacent slats to obtain a plurality of printhead blanks. Each blank is machined to smooth the exposed print wires. The resultant printheads may be used in page- width nonimpact printers.

Abstract: A receiver for demodulating a single sideband signal which is subject to rapid phase jitter employs a Hilbert splitter for obtaining the Hilbert transform of the single sideband signal, and a local oscillator for signal demodulation. A post-oscillator feedback loop instantaneously derives the amount of phase jitter in the single sideband signal, and employs the derived phase jitter to adjust the phase of the local oscillator so that the local oscillator tracks the single sideband signal.Instantaneous derivation of the phase jitter is obtained because all post-oscillator signal manipulations are algebraic; post-oscillator Hilbert transform generation is not required. A first embodiment derives the exact amount of phase jitter. A second embodiment, more simple than the first, derives the approximate amount of phase jitter.