Abstract: Thin film interference filter consists of alternating first and second layers, the first layers being silica, the second layers being a mixture of tantala and niobia. The filter may be used on a high temperature lamp in an inert atmosphere if the niobia in the mixture is less than 40% by weight. For higher percentages a partial pressure of oxygen has been found to prevent blackening of the layers.

Abstract: An improved method for Time Division Multiple Access (TDMA) communications particularly applicable to a network comprising transmitters having significantly different transmission paths to a common receiver. The common receiver measures the response time from each transmitter, relative to a common time reference, then instructs each transmitter to delay all subsequent responses by an amount specific to each transmitter, as determined from these measured response times. This imposed delay results in a more time efficient TDMA protocol, improved error detection capability, and improved security capabilities. This invention is particularly applicable to bi-directional communications to and from a provider of Cable TV, Telephony, and Data Services.

Abstract: A bus bridge for interconnecting a plurality of buses, which bridge includes a plurality of bridge portals, each portal being coupled to a respective one of the buses, and further includes a plurality of switching subsystems, each of which is coupled to a respective one of the bridge portals. The plurality of switching subsystems collectively constitute a switching system which interconnects the plurality of bridge portals. The bus bridge further includes a plurality of cycle clock subsystems, each of which is operatively associated with a respective bridge portal and the respective switching subsystem coupled thereto. Each cycle clock subsystem includes a cycle clock generator which generates a cycle clock, and a cycle counter which receives the cycle clock at a reset input thereof and produces a cycle count output which constitutes a common timing reference for the respective switching subsystem and the respective bridge portal. The bus bridge is preferably an IEEE 1394 serial bus bridge.

Abstract: A frequency calibration circuit for use in a spread spectrum receiver. The receiver includes circuitry for receiving a spread spectrum signal from a base station and for recovering a network clock signal therefrom, a low frequency oscillator for producing an oscillator clock signal, and a frequency comparator that takes as inputs the network clock signal and the oscillator clock signal and produces a calibration factor based on the difference between the clock signals. A controller coupled to the low frequency oscillator amd the frequency comparator utilizes the calibration factor together with the low frequency oscillator clock signal to output a accurate and precision timed signal thereby being able to accurately require the timing of the paging channel.

Abstract: An information storage system is described which comprises a reading device (6) and an optical record carrier (5) having at least two information planes (1, 2, 3). The radiation from the record carrier is converted in a detection system (15) into a detection signal (16) which is applied to a detection circuit (17). In order that this circuit can derive the read information from the detection signal in a reliable manner, the interference signals generated by the information planes which are not to be read should comply with a requirement, referred to as the interference requirement, which is characteristic of the detection circuit. Values for the parameters of the record carrier, such as the thickness of the layers between the information planes and the reflection and transmission coefficients of the information planes then follow from this interference requirement.

Abstract: HID lamp has a U-enhancer connected between first and second leads for an arc tube. The UV-enhancer has a quartz envelope containing an electrode connected to the first lead, and is surrounded by a metal ring which is spaced from the envelope by a sleeve of borosilicate glass. The ring is capacitively coupled to the envelope and is electrically connected to the second lead, which may also support the sleeve.

Abstract: A microwave monolithic integrated circuit includes a coplanar waveguide (CPW) formed by a composite silicon structure constituted by a relatively high resistivity substrate, a first oxide layer on the upper surface thereof, a relatively thin silicon layer formed on the surface of the first oxide layer, and a very thin second oxide layer formed on the surface of the thin silicon layer. The silicon layer and the first oxide layer on which it is formed constitutes a silicon-on-insulator or SOI structure. A metallic signal line and ground planes are bonded to the surface of the second oxide layer. The zone of the thin silicon layer which extends between the ground planes is doped with an active impurity to produce high conductivity therein. As a result, the electric component of a quasi-TEM wave traversing the waveguide is substantially restricted to the thin silicon layer and does not penetrate to the underlying bulk silicon substrate.

Abstract: A method of achieving seamless switching of digitally compressed signals. The method includes the steps of identifying the point in a video signal where splicing to a second video signal is desired, and thereafter, maintaining adherence to certain parameters in the encoder buffer to ensure that the input signal is not being compressed at a rate that causes either underflow or overflow in the encoder buffer. The method also includes the steps of constraining the upper bound of the encoder buffer to ensure that data is not being outputted from the encoder buffer to the decoder buffer too slowly so as to cause an underflow of data in the decoder buffer. The method may also include the steps of constraining the lower bound of the encoder buffer to ensure that data is not being outputted from the encoder buffer to the decoder buffer too quickly so as to cause an overflow of data in the decoder buffer.

Abstract: A high pressure gas discharge lamp and the method of making same utilizing integrated circuit fabrication techniques. The lamp is manufactured from heat and pressure resistant planar substrates in which cavities are etched, by integrated circuit manufacturing techniques, so as to provide a cavity forming the gas discharge tube. Electrodes are deposited in the cavity. The cavity is filled with gas discharge materials such as mercury vapor, sodium vapor or metal halide. The substrates are bonded together and channels may be etched in the substrate so as to provide a means for connection to the electrodes. Lamps having ignition enhancing and hot restrike features, as well as single-sided electrodes, are disclosed.

Abstract: A structure and method for a collection system for a projector includes a collector for reflecting light and a correcting mechanism for receiving the reflected light. The collector and the correcting mechanism, in combination, correct the light and output a light beam having a uniform image size.

Abstract: A high pressure gas discharge lamp and the method of making same utilizing integrated circuit fabrication techniques. The lamp is manufactured from heat and pressure resistant planar substrates in which cavities are etched, by integrated circuit manufacturing techniques, so as to provide a cavity forming the gas discharge tube. Electrodes are deposited in the cavity. The cavity is filled with gas discharge materials such as mercury vapor, sodium vapor or metal halide. The substrates are bonded together and channels may be etched in the substrate so as to provide a means for connection to the electrodes. Electrodeless RF activated lamps may also be fabricated by this technique. Lamps fabricated from three or more planar substrates are disclosed.

Abstract: A high-pressure discharge lamp is disclosed having a discharge vessel, an outer bulb enclosing said discharge vessel and defining an intervening space therebetween, a UV-enhancer positioned in the space between the outer bulb and the discharge vessel, the UV-enhancer provided with a wall fabricated of a ceramic material and an internal electrode, wherein an end portion of the UV-enhancer is closed with a compressive seal.

Abstract: The invention provides a method of constructing an electrolytic capacitor with a heat sink, which includes attaching a surface area of the heat sink in intimate contact with a surface area of the capacitor. The invention also provides a method of constructing an electrolytic capacitor with a heat sink which includes the steps of (i) selecting a surface area of the electrolytic capacitor and a surface area of the heat sink for intimate contact, and (ii) attaching the surface area of the heat sink in intimate contact with and the surface area of the electrolytic capacitor. Moreover, the invention provides for an electrolytic capacitor constructed in accordance with the methods described above and also for a device including an electrolytic capacitor having a surface area in intimate contact with a surface area of a heat sink.

Abstract: A color control system for projection television displays having a projection lamp, a light valve and a device for varying the color of the light from the projection lamp, such as a color wheel. The color wheel driver provides an output signal which represents the position, that is the color, of the color wheel disposed in the lamp beam. The lamp driver varies the output power used to drive the lamp in response to the particular color of the color wheel disposed in the beam. If the projection lamp has a deficiency in a certain color the present system provides greater output power to the projection lamp during the presence of the filter for that color. A user input control provides for changing the tint of the system based on user preferences and/or any changes occurring in the color filters or projection lamp.

Abstract: In portable stereo radio receivers and television receivers, the loudspeakers therein may be separated only by a limited amount. This severely restricts the stereo image created by the loudspeakers. A circuit arrangement for creating an expanded stereo image may be incorporated in such receivers. This circuit arrangement includes, for each stereo channel, a first and a second all-pass 0.degree.-180.degree. phase shifter, wherein the first phase shifter shifts the input signal by 90.degree. at a frequency of 10 KHz, while the second phase shifter shifts the input signal by 90.degree. at a frequency of 100 Hz. The output from the first phase shifter in the left channel is combined with the output from the second phase shifter in the right channel to form the left channel output signal. Similarly, the output from the first phase shifter in the right channel is combined with the output from the second phase shifter in the left channel to form the right channel output signal.

Abstract: A method uses a computer-controlled algorithm that enables production of high-quality layouts and charge maps or set-ups for arbitrary printed circuit boards for electronic component placement machines alone or as one of many in a production line. A class of algorithms known as genetic algorithms employing an initial population of chromosomes are used. Each chromosome represents a set of parameters that control how a layout and charge maps are generated. Problem descriptors, based on one time code are generated. An adaptive searcher searches parameters and generates trial solutions as chromosomes and a heuristic layout generator interprets these chromosomes to generate the layout and charge maps using the problem descriptors.

Abstract: In portable stereo radio receivers and television receivers, the loudspeakers therein may be separated only by a limited amount. This severely restricts the stereo image created by the loudspeakers. A circuit arrangement for creating an expanded stereo image may be incorporated in such receivers. This circuit arrangement first forms a combined monaural signal and a differential signal from the two stereo signals. The differential signal is then subjected to a phase shift. The phase-shifted differential signal is then matrixed with the combined monaural signal to form output stereo signals. When reproduced through stereo loudspeakers, the stereo image appears to be greatly expanded, beyond the limited placement of the loudspeakers.

Abstract: A video server includes a plurality of input/output devices coupled to a plurality of memory arrays via a commutator. Within each memory array, a buffer is operative to collect data for transfer to and/or from an array controller. Each memory array includes an error correction system providing parity-based RAID type error correction. A plurality of disk controllers each having a FIFO buffer and respective pluralities of disk memories are commonly coupled to a communication bus which in turn is coupled to the error correction system by a FIFO buffer. A segment buffer having a plurality of low cost memory devices which are configured to provide a plurality of ring buffers is coupled to the data bus. An access logic circuit controls the data flow through the FIFO buffer and a central processing unit is operative to provide address sequence upon the communication bus for controlling data transfer to and from the segment buffer.

Abstract: Digital mammograms are automatically segmented into background, corresponding to the region external of the breast, and foreground, corresponding to the region within the breast, by the detection of the skinline which forms a border between these regions. A binary array is produced representing an initial coarse segmentation between foreground and background. The binary values are assigned in dependance on the sign of a spatial derivative approximating a gradient normal to the skinline. Spatial derivatives in fixed directions making a substantial angle with respect to the normal to the chest wall approximate the normal to the skinline direction in medial, lateral and lower contour sections of the breast, while a spatial derivative normal to the chest wall approximates the gradient normal to the skinline in anterior and upper contour sections of the breast.

Abstract: A method for pair-match Huffman transcoding a Huffman-encoded bit stream (e.g., an MPEG digital video bit stream) which includes a plurality of qualifying and non-qualifying types of variable length original code words to be processed by a variable length decoder (VLD) with two-word bit stream segmentation, wherein the VLD has a decoding, window N bits wide. The method includes the steps of pair-match Huffman transcoding at least selected ones of the qualifying types of code words to produce corresponding transcoded code words in such a manner that the combined length of any pair of the transcoded code words is .ltoreq.N. A device for implementing this method, as well as a high-performance variable length decoder with two-word bit stream segmentation which utilizes this method, are also disclosed.