Gaseous, liguid and solid fuels are recovered from carbonaceous organic waste material by treating charges of waste material in several successive stages including preheating, drying and conversion into solid and gaseous phases, all as a result of heating in a common vessel or in two or three successive vessels. The solid phases are thereupon cooled prior to admission into a bin, either in a separate vessel or in the vessel for conversion into solid and gaseous phases. The gaseous phases are treated to separate oil from reaction water, combustible gases and inert gases. The charges are heated from without and are sealed from the atmosphere during all four stages of treatment. Each charge is mixed during heating and the intensity of mixing action, the heating action and/or the pressure in the vessel can be varied during one or more stages.

The invention relates to a process and to an apparatus for treating waste materials, especially for recovering fuel from organic substances. More particularly, the invention relates to improvements in processes and apparatus for treating waste materials at elevated temperatures and under exclusion of air.
The quantity of domestic and industrial waste is on the increase at an alarming rate and, therefore, orderly disposal of such waste is of utmost importance and urgency. Experts in the field of waste material disposal predict that, within decades, the expenditures for disposal of waste material will match those for numerous costly public projects such as education and road building. Moreover, while the available supplies of fuel and other basic materials are steadily decreasing, waste materials contain large quantities of recoverable and reusable ingredients. This applies not only for untreated refuse but also for decomposed waste materials such as sewage sludge as well as purely biological waste materials, for example, discarded surplus agricultural products and rapes which develop in wineries, breweries and similar plants.
Recovery of valuable substances from waste materials is an important industry in many developed countries. For example, it is well known to heat dried sewage sludge in the absence of air in order to convert it into coke, oil, combustible and non-combustible gases and reaction water.
Published German patent application No. 30 42 964 of Bayer discloses a process for recovering solid and flowable fuels from biological materials. The material to be treated is heated to between 200.degree. and 600.degree. C. for intervals of time which depend upon the nature of treated material.
Published European patent application No. 0 052 334 of Bayer discloses a continuous process for treatment of solid starting materials (such as granular or pulverulent sewage sludge) which involves conveying the material to be treated through a tubular reaction vessel by a feed screw. The treatment takes up an interval of 2-3 hours, and the material is heated at a rate of 5.degree.-30.degree. C. per minute.
Published German patent application No. 36 05 638 of Hatlapa discloses a process for recovery of gases from an organic material which is admitted into the narrower end of a conical centrifuge and is pushed forwardly by the following material. Admission of air at the outlet of the centrifuge results in pyrolysis which entails the generation of low-temperature carbonization gas.
German-language publication "Korrespondenz Abwasser" (Volume 6, 1982, pages 377-381) discloses four different apparatus for continuous recovery of oil from biomass, namely a furnace which employs a screw conveyor, a rotary tubular kiln, a furnace which operates with a conveyor band and a shaft furnace. Each such apparatus provides a single treating chamber for continuous transport of waste material therethrough. The apparatus differ from each other only in the nature of means for conveying the material. The pressure which is applied to the treated material is identical in each part of the chamber; as a rule, the pressure slightly exceeds atmospheric pressure so as to ensure expulsion of low temperature carbonization gases from the chamber. The speed of transport of treated material must be changed uniformly in each and every part of the chamber. Therefore, degasification of the material can be influenced merely by changing the period of dwell of successive increments of material in the chamber and by changing the temperature in the chamber.
Published European patent application No. 0 003 803 of Solbakken et al. discloses a process and a plant for manufacturing carbonaceous solids and hydrocarbons from discarded tires. The tires are comminuted, relieved of metallic reinforcing material and subjected to pyrolysis in a revolving tubular vessel. The treated material advances continuously, first through the tubular vessel and thereupon through a cooling unit.
U.S. Pat. No. 1,674,420 to Trumble discloses a process and an apparatus for recovering oils from oil shales. The material to be treated is admitted first into a preheater, thereupon into a main treating (distilling) chamber, and finally into a cooling chamber. The treatment involves contacting the material with steam.
Australian patent No. 119,700 to Jacomini discloses a process and an apparatus for treating oil shale. Batches of oil shale are admitted alternatingly into two retorts in each of which the admitted material remains until the treatment is completed. Distillation takes place as a result of admission of preheated gaseous fluids.
Published German patent application No. 29 11 905 discloses a process for neutralization of pulverulent brown coal which is stored in bunkers. The treatment includes filling the bunker prior to sealing its contents from the atmosphere.


An operational amplifier provided with input and output stages comprises detecting means for detecting a differential voltage between a normal input signal terminal and an inverted input signal terminal of aforesaid input stage; and current varying means for varying a current for biasing an output stage buffer in response to an output signal produced from the detecting means. The output stage is driven by an output signal produced from the input stage by means of a single ended output; the detecting means is formed of two transistors constituting a differential amplifying configuration, respective base electrodes of which are applied with respective input signals through the normal input signal terminal and the inverted input signal terminal; each of the two transistors bears each current mirror circuit as a load; one of the current mirror circuits drives one of a complementary SEPP-type transistors on the output stage; and another of the current mirror circuits drives another of the complementary SEPP-type transistors on the output stage through still another current mirror circuit.

1. Field of the Invention
The present invention relates in general to a high-speed and low power consuming operational amplifier employed, for instance, for driving a circuit having a high input capacity such as an analogue to digital (referred to as "A/D") converter or for fast driving a circuit having a low input impedance and, in particular, to those effective to applications which require of extremely low-power consuming operations among general purpose operational amplifiers.
2. Brief Description of the Related Art
Trends toward the low power dissipation, the high operational speed and the miniaturization of the components have been accelerated in response to the recent demands on thinning and down-sizing of equipment and to the technological progression. In the operational amplifiers which act as a sort of arithmetic circuits, the low power consumption and the extremely high operational speed have been achieved by means of a low supply voltage, an unbalanced power supply and a high density integration.
Constitutions shown in FIGS. 6 and 7 have been known up to now as conventional output stages of the operational amplifiers. FIGS. 6 and 7 are block diagrams for showing constitutions of the output stages of the operational amplifiers particularly in detail. FIG. 6 illustrates a circuit which is constituted of bipolar transistors while FIG. 7 illustrates the circuit which is constituted of metal-oxide-semiconductor (referred to as "MOS") transistors. In FIGS. 6 and 7, a numeric character 1 stands for an operational amplifying circuit except for a high drivability output stage, 5 stands for a normal input signal terminal and 6 stands for an inverted input signal terminal. Output signals produced from the operational amplifier 1 are applied to of the output stage wherein the signals are transformed in impedance to be applied to an output signal terminal 7. In either case, an emitter follower configuration or a source follower connection is biased with a constant current circuit 100 or 101 so that an idling current is kept constant. Such constitution of the output stage as mentioned above requires to allot large transistors in size to final stage transistors Q6, Q12, M6 and M12 in order to drive heavy loads which is connected to the output terminal 7.
However, because aforesaid conventional examples require to drive either a base or a gate electrode of the large transistor in chip size with a constant current, it is necessary to enlarge the constant current value for accelerating the driving speed. Accordingly, there has been a problem that an increase in dissipated current obstructs a reduction in power consumption.


Locating and recognizing characters on a machine produced label, for example, is accomplished faster and more accurately by searching for first and second identifiable objects within first and second search windows, respectively. The first and second search windows are typically much smaller than the label or image being searched. The first object is the top portion of the label and the second object is the bottom portion of the label. Having located each object, a reference point is determined on each. From these two reference points, precise character or bar code locations can be predicted for reading the characters or bar codes printed on the label at predetermined locations. A character search window superimposed over each character at its estimated location is searched to read the character located thereat. If the first or second object could not be located, due to a torn label for example, an alternate object may be searched and a reference point located thereon.

Computers, in performing many tasks previously accomplished by humans, are required to optically recognize objects or codes. Machine vision systems, therefore, are coupled to computers for performing recognition functions. Optical character recognition (OCR) software, for example, is used to drive a scanner for scanning a page of text. Characters recognized on the scanned page are electronically transferred to the computer.times.s memory, thereby relieving a data input operator from manually inputting the document contents. Another common function for machine vision systems is scanning items having bar codes impressed thereon. The bar code is more easily recognized than alpha-numeric characters and may therefore be useable in harsher environments. Bar codes, for example, are optically read from packages for inputting price and product description information into a computer.
More sophisticated systems merge a robot with a machine vision system, for example, a camera located on a robotic arm, the camera and robotic arm being controlled by a processing unit. The machine vision system can be taught to recognize certain objects so that the robot can grip and manipulate the identified objects. In automated data storage libraries, a robotic arm is directed to a slot storing a cartridge containing a data storage medium, i.e., a magnetic tape or optical disk. A camera located on the robotic arm, attempts to read alpha-numeric characters or bar code impressed on a label attached to the cartridge to identify the cartridge or verify the cartridge being picked by the robotic arm is the expected cartridge.
In the above described machine vision systems, the characters or bar code must first be located. Once located, the characters or bar code must be read. For a machine vision system to operate efficiently, it must locate the characters or bar code quickly and read the characters or bar code accurately. Locating characters or objects, for example, typically requires searching a large image or area, i.e., a page, a package, a label, or everything within a camera's field of vision. The time required to locate the characters or objects is related to the image size or area to be searched. Once the characters are located, a smaller search window is viewed in an attempt to identify individual characters. An erroneous character reading may occur when a character is not fully within a search window, or when more than one character appears in the search window.
A method for improving OCR efficiency is taught by Tanaka, et al., in U.S. Pat. No. 4,926,492. This invention searches an image, i.e., a page, and divides the image into character lines. Picture elements are then counted in several different directions for determining character positions. In Tanaka, et al., a large image must still be searched, and each individual character location must be determined within a window though the character line information is used to reduce the window size somewhat. Peppers, et al., in U.S. Pat. No. 4,809,344, describe segmenting a page by simultaneously identifying multiple features including separation between lines and separation between characters. A page having both vertical and horizontal text would be segmented so that each segment could be handled more efficiently. Like Tanaka, et al., this implementation still requires searching a large image for recognizable characters.
A method for locating bar codes, even on an image having background noise, is described by Raphael in U.S. Pat. No. 4,916,298. The bar codes are detected by comparing areas of the image to a predetermined threshold (indicating light reflection or absorption). Once a suspected bar code is located, a smaller image area or window surrounding the bar code is viewed in an attempt to read the bar code. Raphael provides a faster method for finding bar codes but still teaches first scanning an entire image and then windows within that image. Guthmueller, et al., in U.S. Pat. No. 4,822,986 takes advantage of the knowledge that postal zip codes printed on envelopes as bar codes will be printed near the envelope bottom. Guthmueller, et al., only searches the bottom portion of the envelope when locating the bar codes. Efficiency is improved by reducing the image area being searched. Finding the bar codes is then accomplished by recognizing the bar code image.
Another method of reducing the time required to locate regions of an image containing bar codes is set forth by Lee, et al., in U.S. Pat. No. 4,948,955. This method first reduces the background image, then rejects background noise while attempting to locate a bar code. Once the bar code is found, the four corner points defining the bar code's boundary are determined. Like the other prior art, this invention requires searching a relatively large image area while trying to identify characters or bar code, sometimes in the presence of background noise.
Machine identifiable characters or bar codes are often printed on a page or label at predetermined locations. Substantial processing time may be saved by quickly identifying easily recognizable objects for establishing reference points, and then determining where the identifying characters or bar codes are located. The need for scanning an image for recognizable characters in the presence of noise would no longer be required.
Thus what is needed is a machine vision system for quickly finding easily recognizable objects for establishing reference points from which actual character or bar code locations may be predicted.

Apparatus and method for locating characters on a label

International Business Machines Corporation


A barbell includes a bar assembly that includes a sleeve rotatably fitted over a rotating-locking mechanism at an end of a shaft; and an end cap attached to an open end of the sleeve to enclose the rotating-locking mechanism and the end of the shaft inside the sleeve, in which the rotating-locking mechanism includes a supporting ring rotatably fitted over the shaft and a joining ring attached to the end of the shaft, in which the supporting ring abuts, on one side, a shoulder on an inner surface of the sleeve and, on the other side, the joining ring.

1. Field of the Invention
The invention relates generally to exercise equipment. Specifically, this invention relates to weight-lifting equipment, such as Olympic bars.
2. Background Art
When one lifts a barbell from the ground to a position above one's head, the bar rotates 180 degrees. If weight plates do not rotate freely, they would generate a substantial torque that would be transmitted to the lifter's wrist/skeletal systems. Because the weights lifted by athletes may range from 100-500 lbs or more, such torque transfer not only can be painful, but also can cause an "overuse injury" to the athletes. For safety and comfort, barbells may be equipped with rotating sleeves to allow weight plates to rotate and to make strength training more productive and safer.
Olympic barbells (Olympic bars) are specially designed for professional use at Olympic games and other competitive events. Common features of Olympic bar designs include sleeves that can rotate freely and smoothly, while supporting the weight of the plates. This makes it easier for user to practice more "explosive" weight lifting.
An Olympic bar for men is about 2.2 m (7.22 ft) long and weighs about 20 kg (44.1 lbs). The outer ends (rotating sleeves) are about 50 mm (1.9685 in) in diameter for accommodating the weight plates, while the grip section is about 28 mm (1.1024 in) in diameter, and 1,310 mm (51.57 in) in length. A women's Olympic bar is similar to the men's bar, but is shorter—2.05 m (6.73 ft)—and lighter—15 kg (33.07 lbs)—with a smaller grip section diameter (25 mm).
To allow sleeves to rotate freely, Olympic bars typically incorporate bushings, ball bearings, or needle bearings in their rotation mechanisms. Because needle bearings have long, thin bearing elements that have more surface areas than ball bearings, needle bearings can take the weight loads better and are preferred over ball bearings. In addition, bushings are commonly used because of their durability and low maintenance.
In addition to the rotation mechanism, the Olympic bars also need to have a retention mechanism that allows the rotating sleeves to stay on a shaft (i.e., without longitudinal sliding), while allowing the rotating sleeves to have free rotation. Common retention mechanisms may include bolts, pins, or snap rings. An example that uses a bolt to secure a rotating sleeve to a handle bar is shown in FIG. 1, while an example that uses a roller pin is shown in FIG. 2.
FIG. 1 shows a cross-sectional view of a bar assembly 10 that uses a bolt to join the rotating sleeves and the shaft, as disclosed in U.S. Pat. No. 6,770,016 issued to Anderson et al. As shown, the bar assembly 10 includes a shaft 14 (a handle bar). A sleeve 12 is slide over the shaft 14. The sleeve 12 together with an end element 11 are retained on the shaft 14 by a bolt 16. The bolt 16 is threaded into a female threaded end portion 18 on the shaft 14. Once the bolt 16 is fixed at the end portion 18 of the shaft 14, it helps to retain the end element 11 and the sleeve 12 on the shaft 14 and prevent them from sliding off the end of the shaft 14.
To allow rotational freedom of the sleeve 12 around the shaft 14, the bolt 16 passes through a hole in the end element 11 and is then threaded into the end portion 18 of the shaft 14. The bolt 16 is inserted inline with the longitudinal axis of the shaft 14 (or the rotational axis of the sleeves 12) to allow the sleeve 12 to freely rotate around the shaft 14. However, sleeve rotation might from time to time exerts rotational force on the bolt 16. As a result, the bolt 16 may gradually come loose.
An alternative to a bolt is to use a roll pin or a snap ring to retain a rotating sleeve on a shaft. With this mechanism, a roll pin or a snap ring is lodged in matched grooves on the shaft and the rotating sleeve to prevent them from sliding in the longitudinal direction, while allowing rotational motions. FIG. 2 shows an example of a bar assembly 20 that uses a roll pin to retain a rotating sleeve on a handle bar.
As shown in FIG. 2, a bar assembly 20 includes a roll pin 26 to retain a sleeve 22 on a shaft 24. The roll pin 26 may be made by rolling a piece of metal in a way that it would exhibit elasticity such that it can be forced into a groove 28. Once lodged in the groove 28, the roll pin 26 can expand to lock the sleeve 22 on the shaft 24 to prevent the sleeve 22 from sliding off the end of the shaft 24. In a similar manner, a snap ring (in a form of an incomplete circle) can also be used (instead of a roller pin) to retain sleeve 22 on the shaft 24. In order to allow a roller pin 26 (or a snap ring) to fit into the groove 28, the thickness of the roll pin 26 must be smaller than the width of the groove 28. As a result, there is small gap (clearance) in the groove/roller pin setup. The gap allows the sleeve 22 to slide longitudinally on the shaft 24, albeit very slightly. In addition, while the grooves may be only millimeters deep, such grooves would weaken the bars and the sleeves.
While these prior art approaches to sleeve retentions on the shafts (e.g., using bolts, pins, and/or snap rings) are satisfactory in most situations, there is still a need for improved mechanisms to secure rotating sleeves on shafts.


A method and system for handover of a video call from a packet switched network to a circuit switched network by a first network entity associated with the packet switched network in a single radio environment is provided. A need to perform a video single radio voice call continuity (vSRVCC) handover from a packet switched network to a circuit switched network is detected during a video call session in the packet switched network. Accordingly, a vSRVCC handover request is transmitted to a second network entity associated with the circuit switched network for performing the vSRVCC handover of the video call session where the vSRVCC handover request includes vSRVCC capabilities of a user equipment (UE) associated with the video call session.

1. Field of the Invention
The present invention generally relates to wireless communication systems, and more particularly, to handover of video calls from a packet switched network to a circuit switched network in a single radio environment.
2. Description of the Related Art
An SAE/LTE system is a packet switched (PS) system in which voice and video calls are established through a PS domain. Therefore as a "default option", voice calls use the PS domain as packet video-calls and underlying call control protocol is SIP supported through an IP multimedia subsystem (IMS). Recently, there has been a slow migration of users from the SAE/LTE domain from a circuit switched (CS) domain to the LTE packet switched domain. Hence, the LTE system may be deployed in "islands" overlaying parts of the CS domain. This means that if a user makes a video-call over the LTE system, the video-call may not be just subject to an intra-domain handover (i.e., radio-level and intra-network-level handover) but is also likely to be subject to an inter-domain handover from the LTE packet domain to the CS domain due to mobility of the user during the video-call. This leads to the development of a functionality called Single Radio Voice Call Continuity (SRVCC) in the Third Generation Partnership Project (3GPP) technology. SRVCC is a functionality that allows a voice/video call in the LTE packet domain to be moved to the CS domain.
CS video-calls support a feature called "Service change for UDI/RDI fallback" (normally referred to as a service change and unrestricted digital information fallback (SCUDIF)). This service is available to UDI/RDI multimedia calls and allows users to achieve successful call establishment when end-to-end CS multimedia is not possible (fallback to speech) or when signaling of the feature is not possible in the CS network (fallback to preferred service or speech). Furthermore, it allows users to swap between a multimedia service and basic speech during an established call.
Nevertheless, in the case that the call (either voice-call or video-call) has been established in the IMS, there is no negotiation that normally takes place between user equipment (UE) and a mobile service centre (MSC) in order to mutually identify whether both the UE and MSC support the SCUDIF feature; hence it is not possible to use the SCUDIF feature when the UE moves to the CS domain from the PS domain. For example, if a voice/video call has been initiated with the PS network and later handed over to the CS network using an SRVCC, there is no communication that takes place between the UE and the MSC during the call setup time. As a consequence, the UE and the MSC are unaware of each other's SCUDIF capabilities (user-initiated or network-initiated) when the voice/video call is transferred to the CS network.
Further, a delay may be introduced by H.324 when performing the following steps for call setup:                H.223 Multiplexer level detection        Terminal Capability Exchange        Master Slave determination        Open Logical Channels        Multiplexer Table Entries Exchange
The procedure typically takes 5˜8 seconds. If link quality deteriorates or media configurations between UEs are not well-matched, this delay may increase even further. The delay can be suppressed to as low as a few seconds in limited cases when the acceleration techniques are supported by both UEs and little data is lost during the period. However, the call set up procedure of 3G-324M, outlined above, is likely to occur at cell edges under the SRVCC situations where radio link is unstable.
Given that the period of the current SRVCC handover with voice only is significantly smaller (e.g. in the range of 300-500 ms) if simultaneous transfer of voice and video is performed when a handover from PS-to-CS network with video SRVCC (given that a 64 kbps bearer is established on the UTRAN side and the increased call setup delay of 3G-324M from the negotiation between UEs using H.245 signaling procedures) interruption time might be significantly large, during which a message might be displayed to ask for patience from the user or recently-played video clips might be replayed until newly-decoded scenes become available.

Method and system for handover of video calls from a packet switched network to a circuit switched network in a single radio environment


An interpolating digital signal clipping circuit provides pre-clipping of the luminance component of a video signal. A difference circuit adjusts each sample so that a single bit indicates whether the sample value is closer to a positive or negative clipping limit. Interpolated samples are produced by phase shifting FIR filters and are applied, along with the actual current sample, to a minimum or maximum selecting circuit that selects the minimum or maximum sample depending on the state of the indicating bit. The selected sample is compared with the clipping limits to produce an excess signal that indicates how much the selected sample exceeds the relevant clipping limit. A gain control signal is generated to be a "1" when no clipping is required and less than one when clipping is required. A digital video signal clipping circuit receives this pre-clipped luminance signal and adjusts each sample as above. Multipliers square the chrominance components, and an adder adds the squares and applies the output as addresses to a memory that produces a chrominance magnitude signal. The chrominance magnitude signal is combined with the adjusted luminance signal to obtain a composite magnitude signal. Again, a gain control signal is generated that is a "1" when no clipping is required and less than one when clipping is required, and this signal is used to reduce the video components before they are combined into a clipped composite video output.

This invention relates to the clipping of digital signals, and more particularly to clipping of digital video luminance and chrominance components so that the resulting composite digital video signals are within desired clipping limits.
A typical prior art digital clipping circuit is shown in FIG. 1. As long as the value of the input signal is less than the positive clipping level and greater than the negative clipping level, the input signal is passed through the multiplexers to be the clipped signal output. However, if the value of the input signal becomes greater than the positive clipping level, the positive clipping level is substituted for the input signal as the clipped signal output. And, similarly, if the value of the input signal becomes less than the negative clipping level, the negative clipping level is substituted for the input signal as the clipped signal output.
Ideally, performing clipping operations on a signal input such as that shown in FIG. 2A leads to a clipped signal output as shown in FIG. 2B. However, in a digital implementation of a clipping circuit, as the frequency of the signal being clipped increases and begins to approach half of the sampling frequency, clipping of the individual sampled points does not necessarily provide adequate clipping of the reconstructed analog signal.
FIGS. 3A through 3C illustrate the problem that results from a low sampling rate relative to the frequency of the signal being clipped. The waveform shown in FIG. 3A clearly exceeds the positive and negative clipping levels indicated by the dotted lines. Even though four samples are taken, only one of these is a sample that occurs during the time that the signal is in excess of the clipping levels, and that sample occurred when the signal was only slightly above the positive clipping threshold. The whole negative excursion of the waveform below the negative clipping threshold occurred between the third and fourth sample points and, consequently, was not detected and produces no clipping. Thus, it can be seen that, at a low relative sampling rate, the effectiveness of the clipping of the signal depends on the phase relationship between the signal and the sampling times.
As can be seen in FIGS. 3B and 3C, even though the second sample is clipped to the positive clipping level and this somewhat diminishes the positive going amplitude of the reconstructed waveform, the reconstructed waveform still exceeds both clipping levels, especially the negative one. Moreover, the partial clipping that does occur introduces into the reconstructed waveform phase distortion and discontinuities that appear as higher frequency components.
Of course, a higher sampling rate is always one approach to avoiding this problem, but oversampling itself can produce some undesirable effects such as ringing, and is not economically feasible or technically desirable in most circumstances.
As shown in FIG. 7, conventional video processing amplifiers of the prior art generally include a circuit to permit controllable clipping of the luminance level before it is re-combined with the chrominance signal to produce the composite video and another circuit to permit controllable clipping of the composite video signal after the luminance and chrominance have been combined. A limitation that is inherent in this approach is that the composite signal is "hard" clipped without any attention to the subtleties of its component parts.

Interpolating digital signal clipping circuit and composite video clipping circuit utilizing same


An exemplary embodiment of the present invention is a flyer bow having a first surface and a second surface in opposition to the first surface. The first and second surfaces are joined to form an airfoil shape. A channel passes through the flyer bow between the first and second surface and a wire guide is disposed within the channel. There is at least one orifice through one of the first and second surface thereby establishing fluid communication between the channel and the ambient atmosphere.

This invention relates to flyer bows. Flyer bows for use on twisting machines are well known in the art. Twisting machines with flyer bows can be used to make twisted cables for a wide variety of uses. Flyer bows, including those related to this invention, can be used with pairing, tripling, quadding, bunching and twisted machines for wires. A typical flyer bow is generally rectangular in cross section. Wires to be twisted pass longitudinally along the inside surface of the flyer bow and are guided along the surface through ceramic or metal wire guides. A groove or recess in the inside surface of the flyer bow is often incorporated into the design of the flyer bow in order to nest the wires to be twisted close to the surface of the flyer bow. This configuration minimizes drag on the wires due to wind that sweeps transversely across the flyer bow during use. Flyer bows with airfoil shapes have been successfully used to increase speed of the winding machines with the benefits of minimum power draw and reduced operational noise. However, the airfoil does little, if anything, to minimize the effect of drag on the exposed wires. Furthermore, the exposed wire guides create additional drag on the flyer bow as it rotates.
A typical construction and operation of a twisting machine and flyer bow is disclosed and described in U.S. Pat. No. 3,945,182, the entire contents of which are incorporated herein by reference. As described in U.S. Pat. No. 3,945,182, a typical flyer bow is arcuate along its length and transversely flat. That is, it is generally rectangular, or at least has opposed flat parallel faces, and it is arcuate along its length. U.S. Pat. No. 3,945,182 discloses the feature of incorporating a groove or recess in the inside surface of the flyer bow and a corresponding ridge or protrusion on the outer surface of the flyer bow. The wires to be twisted nest within the groove to protect the wires from windage that sweeps transversely across the flyer bow as it rotates along its orbital path around a longitudinal axis.
Typical prior art flyer bows have wire guides mounted on the inner surface. These wire guides are typically semicircular in shape and present a flat and blunt exposed air surface. The prior art wire guides are typically secured to the flyer bow by nuts which extend above the top surface of the flyer bow and are exposed to air as the flyer bow rotates. All of this creates drag of the flyer bow as it rotates.
U.S. Pat. No. 5,509,260 discloses a guiding bow for an elongated element in a twisting or winding apparatus. At least part of the length of the guiding bow has a transversal cross section which is streamlined. The core of the guiding bow may be made of a load carrying material, the sheath of a synthetic material.
U.S. Pat. No. 5,809,763 discloses a flyer bow having inner and outer surfaces, and at least one surface is curved to form an airfoil in cross section.
U.S. Pat. No. 4,072,003 discloses a double twisting machine of a flyer type, which comprises a pair of rotatable fliers, a pair of bow guides formed with a through bore for allowing wire elements to pass therethrough, two pairs of guide holders each retained in one of each of the fliers for holding one end of each of the bow guides and two pairs of shock-absorbing elastic members each interposed between each of the fliers and each of the bow guides through the corresponding one of the guide holders. The fliers are in spherical contact with the guide holders so as to assure smooth swinging motions of the bow guides.

Flyer bow with integral enclosed wire guide


A method of locating a receiver in a navigation system comprising a constellation of satellites transmitting signals, includes the steps of:. measuring pseudo-distances between the receiver and the satellites from the signals received from the satellites, PA1 measuring pseudo-speeds between the receiver and the satellites from signals received from the satellites, and PA1 computing the position of the receiver from the combination of measured pseudo-distances and pseudo-speeds.. The position of the receiver is computed by minimizing the matrix of covariance of the measured pseudo-distances and pseudo-speeds. This provides an accurate position of the receiver in a simple manner, in particular for a constellation of satellites in low Earth orbit.

The invention concerns satellite navigation systems; these systems, using a constellation of satellites transmitting known signals, enable a receiver to compute its position within a geocentric frame of reference. These systems are used to navigate vehicles of all kinds, in particular ships and aircraft. The systems in use at present are the GPS and GLONASS systems, which comprise constellations of satellites at an altitude of 20 000 km. These systems are based on measuring pseudo-distances between the satellites and the receiver. A pseudo-distance is evaluated from the transmission time of a signal transmitted at a particular moment by the satellite and received by the receiver. For this purpose, the receiver measures the arrival time of the encoded signal transmitted by a satellite of the constellation and reads the time at which the signal was transmitted by the satellite in the received message. The receiver evaluates the transmission time by determining the time the message was received or by computing the phase of the signal.
Knowing the position of the satellites makes it possible to determine the position of the receiver by triangulation on the basis of the pseudo-distances. Existing prior art systems use four satellites to compute the position of the receiver; four measured pseudo-distances are thus used to determine the time and the position of the receiver station.
One of the main features of the above systems is that there is no limit on the number of users, in other words the system cannot be saturated; the satellites merely transmit and position is computed at each receiver. The receiver is therefore passive, operating in "listening" mode. This also implies that the pseudo-distances are measured on the one-way satellite-to-receiver path. Other details on the structure and operation of the above navigation systems can be found in the prior art documents cited below.
U.S. Pat. No. 5,420,592 describes the use of a GPS navigation system for positioning meteorological balloons; it proposes separating the GPS receiver into a mobile part carried by the balloon and a fixed part on the ground. A Kalman filter is used to predict the position of the balloon and enables positioning even with reduced visibility of the constellation of satellites. The system corrects the offsets induced by the Doppler effect in the signals from the satellites to enable correction of the signal from the satellite for fast computation of the pseudo-distance.
EP-A-0 460 862 describes a GPS type global positioning system receiver that can be implemented in a VLSI circuit. The receiver includes means for evaluating the pseudo-distance and the variation in the pseudo-distance in order to eliminate the Doppler effect from the carrier from the satellites.
U.S. Pat. No. 5,436,632 proposes to use the Doppler effect to compute corrections to be applied to the rate of variation of the pseudo-distances in a system for monitoring the integrity of the signals from a GPS type system.
U.S. Pat. No. 5,343,209 proposes to evaluate the Doppler shifts using an estimate of the speed of the receiver and the variations of the line of sight (LOS) of a GPS type positioning system. That evaluation produces an estimate of the phase of the carrier, the frequency of the carrier and the phase modulation of each of the received signals which is better than could be provided by each signal independently.
EP-A-0 518 146 describes a multi-point positioning system for a ship and towed buoys. That system uses a plurality of GPS receivers and Kalman filters to evaluate the quality of each position indication. It is again proposed to correct the Doppler shift for evaluating the pseudo-distances.
U.S. Pat. No. 5,594,453 describes a GPS receiver with a waiting mode to reduce power consumption; in order to enable rapid acquisition of the position on leaving the waiting mode, that document proposes to correct the influence of temperature on the clock frequency. The Doppler effect is used to compute the estimate of the frequency of the satellite in the new position, on leaving the waiting mode.
U.S. Pat. No. 5,557,284 proposes a system for detecting spoofing (the transmission of fake signals) in a global positioning system; it proposes to use the differences in the Doppler effect between two receivers on an aircraft or on the vehicle to detect fake signals.
In all the above documents, as in the prior art in general, the Doppler effect embodied in the signals from the satellites is seen as a drawback; it is proposed to correct the signals received to eliminate the Doppler effect or to allow for the Doppler effect in predicting the position of the receiver. None of the above documents proposes to use measurement of pseudo-speeds by the Doppler effect to improve the accuracy of the position determined. Also, all the above documents concern constellations of satellite in medium Earth orbit (MEO), such as the GPS or GLONASS systems.

Positioning by computing pseudo-speeds in a satellite navigation system


A radar absorbing material comprising multiple layers integrated to form a thin flexible and light weight structure. The material includes a substrate disposed thereon antenna elements that are relatively loaded to enable one to construct a device in relatively small and thin size. The broad handling of the device is carried out by multi-layering concepts in which different size antenna patterns are multi-layered with each layer designed to absorb frequencies in s specified range. The antenna elements are selected for their intrinsic broadband properties and to preferably be polarization insensitive.

The present invention relates in general to radar absorbing materials. More particularly, the invention pertains to an electro-magnetic energy absorber that is characterized by broadband operation. Even more particularly, the invention relates to an electro-magnetic energy absorber that is thin, flexible, lightweight, and preferably operates in a frequency band of 2-18 GHz with less than --15 dB reflectivity.
Two basic forms of radar absorbers are referred to in the prior art as a Salisbury screen and a Dallenbach layer. The Salisbury screen is a resonant absorber formed by placing a resistive sheet on a low dielectric constant spacer in front of a metal plate. The Dallenbach layer consists of a homogeneous lossy layer back by a metal plate. The Salisbury screen has found some limited usage, but is generally ineffective for broadband applications. One of the problems with the Dallenbach layer is the difficulty in providing the proper match of materials. Also, the Dallenbach layer does not provide sufficient bandwidth.
Much effort has been carried out in the past in an attempt to extend the bandwidth of radar absorbers through the use of multiple layers. In this regard, see by way of example, U.S. Pat. No. 2,951,247 to Halpern, et al, U.S. Pat. No. 2,992,425 to Pratt and U.S. Pat. No. 2,771,602 to Kuhnhold. Also refer to British patent 665,747.
In these prior art absorbers, the intention of the use of multiple layers is to slowly change the effective impedance from free space to zero ohms with distance into the material so as to minimize reflections or to provide an input impedance that matches that of free space as closely as possible over a selected range of frequencies. There are, generally speaking, two different types of multi-layer absorbers that are common in the art. These are referred to as the Jaumann absorber, and the graded dielectric absorber. All of these absorbers require the use of multiple layers and are typically relatively thick. Existing broadband radar absorbing materials require thickness of at least one or two inches to achieve any significant bandwidth. Also, the manufacturing process is relatively complex because of the multi-layering of different materials that are used to obtain the broadband enhancement. One example of a commercially available graded dielectric absorber is one made by Emerson & Cumming. This is referred to as their Model No. AN-74 which is a three-layer foam absorber that is over one inch thick.
Accordingly, it is an object of the present invention to provide an improved radar absorbing material that has excellent broadband characteristics and that is yet thin, preferably flexible and light in weight.
Another object of the present invention is to provide an improved radar absorbing material that is in particular usable over a frequency range of 2-18 GHz with preferred reflectivity of less than -15 dB.
A further object of the present invention is to provide a radar absorber that is relatively simple in construction and that can be easily manufactured in production quantities at relatively low cost.
A further object of the present invention is to provide an improved radar absorber in which the overall material thickness is made quite small by employing a process that includes the step of printing antenna patterns using a preferred resistive ink and wherein the antenna patterns may be printed using silk screening techniques.
Another object of the present invention is to provide an improved radar absorber that is characterized by its broadband absorption, and yet is carried out with a thin structure at least an order of magnitude thinner than one inch.
A further object of the invention is to provide an improved radar absorber that is in particular adapted for high temperature applications.

Broadband electromagnetic energy absorber


An optical waveguide device has a casing, a base member housed in the casing, at least one input optical fiber cable and at least one output optical fiber cable which are introduced into the casing, an optical waveguide substrate mounted on the base member and connected to respective ends of the input and output optical fiber cables for transmitting a light signal from the input optical fiber cable to the output optical fiber cable, support bases and holders fixed to the base member for holding end portions of the input and output optical fiber cables on the base member, and a bushing or bushings in the casing for introducing the input and output optical fiber cables into the casing. The optical waveguide substrate has an optical waveguide branched into a plurality of waveguide paths, and input and output optical fiber cables are coupled to each other through the optical waveguide.

1. Field of the Invention
The present invention relates to an optical waveguide device for use in optical communications, and more particularly to a shock-resistant optical waveguide device capable of keeping input and output optical fibers stably connected to an optical waveguide without causing an axial misalignment therebetween.
2. Description of the Prior Art
Known optical waveguide devices have a casing in the shape of a rectangular parallelepiped, a base member supporting an optical waveguide substrate with an optical waveguide formed therein, the base member being fixedly mounted in the casing through a support member of resin, and input and output optical fibers extending into the casing through a bushing on the casing.
The conventional optical waveguide devices are disadvantageous in that they are unable to sufficiently resist external forces such as shocks, tensile forces, or the like, i.e., the optical waveguide and the optical fibers tend to be disconnected or axially misaligned when subjected to external forces.
In many prior optical waveguide devices, the optical waveguide and the optical fibers are spliced by directly bonding and fixing a flat end face of the optical waveguide to flat end faces of the optical fibers. According to one splicing process, it has been necessary to position the optical waveguide and the optical fibers three-dimensionally along X-, Y-, and Z-axes, and then adjust the angles of the optical axes of the optical fibers with respect to the optical axis of the optical waveguide along the X-, Y-, and Z-axes so that the optical waveguide and the optical fibers are axially aligned for higher optical propagation efficiency. If the flat end faces of the optical waveguide and the optical fibers are not sufficiently bonded to each other, however, they can easily be axially misaligned under external forces.
The gap between the bushing and the optical fibers which extends through the bushing into the casing is filled with an adhesive that is simply applied from outside of the casing, thus hermetically sealing the casing. If the adhesive contains air bubbles or the bushing and the optical fibers are bonded through an insufficient adhesive area at the time the casing is shocked, then the casing may not be kept hermetically sealed well.

Optical fiber and optical waveguide connecting device


A sleeving machine and a method for automatically inserting a tray of postal mail into a sleeve. The tray is disposed on a transport station and advanced by a first belt. A second belt having a pusher thereon engages the tray for advancement through the machine. Collapsed sleeves are dispensed as required from a hopper into a sleeving station. Arcuate guides in the sleeving station open the sleeves to receive the tray. The second belt with the pusher advances the tray into the open sleeve and then advances the sleeve, with the tray therein, out of the sleeving station. Sensors are provided to control and coordinate movement of the second belt and dispensing of the sleeves from the hopper into the sleeving station. Safety features are provided.

The postal service has directed considerable resources to improving the sorting and delivery of letters and related postal matters. Automated scanners sort mail by zip code and automatic equipment is available for transporting the mail within the separate postal stations. As part of this concept the postal service employs a system in which mail, such as letters addressed to a single destination (e.g., one zip code), is placed in a marked tray. In order to prevent loss of the individual letters, or the introduction of letters for an alternate destination, the tray is inserted into an open-ended sleeve. Thus, the tray in the sleeve is easily transported. The insertion of the tray into the sleeve is presently being performed manually which is inefficient, slow and labor intensive and is a portion of the overall mail handling approach which is urgently in need of improvement.
An apparatus for inserting articles into open-ended receptacles is disclosed in U.S. Pat. No. 1,407,581 issued to Rose Feb. 21, 1922. Outer members are fed into the apparatus in a collapsed condition by a pair of arm-like pushers and opened by a wedge-shaped member. A reciprocatable slider thrusts the inner member into the outer member. U.S. Pat. No. 3,299,610 issued to Webster Jan. 24, 1967 discloses an apparatus for filling sleeve packages wherein a carton or sleeve is erected at the sleeving station with an open end thereof directed along the path of a package which is moving along a predetermined path toward the sleeving station. The carton or sleeve is held stationary while the package is pushed into the open end of the carton or sleeve. U.S. Pat. No. 4,012,887 issued to Calvert Mar. 22, 1977 discloses a packaging machine which withdraws collapsed sleeve-type containers from a hopper by suction means and sets up the sleeve to receive bottles through the open end. End flaps are closed on the sleeve. U.S. Pat. No. 4,693,055 issued to Olsen, Jr. et at Sep. 15, 1987 disclose a machine for feeding beverage cans to open-ended carrier sleeves. U.S. Pat. No. 4,869,052 issued to Calvert Sep. 26, 1989 discloses a packaging machine. Collapsed sleeve-type articles are withdrawn in sequence from a hopper by suction cup means which then holds each carton at a loading station while a plurality of articles are inserted through an open end of each container. Flaps for the open ends of the container are then closed.
Although the packaging machines are useful for the purposes for which they were designed, a simpler, more efficient sleeving machine is needed for the postal service requirements.


Polymerization of N-methyl norbornene dicarboximide yields polymers of high Tg, e.g. greater than 200.degree. C. Preferred polymers of exo N-methyl norbornene dicarboximide have number average molecular weight of at least 8,000.

Disclosed herein are inventions relating to high temperature-resistant thermoplastic polymers of norbornene dicarboximides and to methods of making and using such polymers. More particular aspects include inventions relating to polymers of N-methyl norbornene dicarboximide.
High temperature resistance, e.g. as measured by heat distortion temperature and glass transition temperature (T.sub.g), is provided in several existing polymer systems, e.g. the polyether imides and the polyamide-imides. In addition to high strength and high modulus, a desirable characteristic of such polymer systems includes processability like more conventional lower temperature thermoplastic polymers.
McKeon et al. in U.S. Pat. No. 3,330,815 disclose the vinyl-type addition polymerization of a variety of norbornene derivatives, including carboximides, to provide polymers free of unsaturation in the chain. Such polymerization is carried out with noble metal catalyst, i.e. palladium compounds.
Reding et al. in U.S. Pat. No. 3,494,897 disclose the vinyl-type addition polymerization including copolymerization with alkenes, of a variety of norbornene derivatives to provide polymers of saturated chains. Such polymerization of copolymers of norbornene derivatives including dicarboximides (see for instance Examples 24 and 25) is carried out in the presence of a free-radical catalyst, e.g. a peroxide.
See also French Brevet d'invention 1,594,934 which discloses polymerization of norbornene dicarboximides with noble metal catalyst, e.g. ruthenium compounds. Analyses reported by Michelotti et al. in
Journal of Polymer Science 3 (1965) pp. 895-905 suggest that ruthenium catalysts may effect polymerization to some extent through a bicyclic double bond without ring opening (see Michelotti et al. at p. 902).
Such noble-metal-catalyzed imide polymers as reported in Brevet 1,594,934 have somewhat low glass transition temperatures (Tg). See, for instance, Example 2 which reports the preparation of a polymer of N-methyl norbornene dicarboximide having a Tg of 185.degree. C. See also Example 14 which reports the preparation of a polymer of N-phenyl norbornene dicarboximide having a Tg of 162.degree. C.
Kurosawa et al., in U.S. Pat. No. 3,959,234 disclose the ring-opening polymerization of norbornene dicarboximides with a catalyst system comprising organic aluminum compounds and tungsten and/or molybdenum compounds. However, multiple polymerization mechanisms may have been involved perhaps due to contaminated catalyst since the tungsten-catalyzed polymers of the working examples are reported as having Tg's similar to the noble metal-catalyzed polymers reported in Brevet 1,594,934. In this regard in the U.S. patent poly (N-methyl norbornene dicarboximide) is reported to have a Tg of 189.degree. C.; in the Brevet a Tg of 185.degree. C. is reported. Similarly, in the U.S. patent poly (N-phenyl norbornene dicarboximide) is reported to have a Tg of 166.degree. C.; in the Brevet the Tg is 162.degree. C.
Other attempts at the metathesis ring-opening polymerization of norbornene dicarboximides have met with apparently limited success. For instance, see Matsumoto et al. at ACS Symposium Series 59 (1977), page 303, who report poor polymer yield (i.e. about 8 percent) in attempts to polymerize monomers of norbornene dicarboximide and N-propyl norbornene dicarboximide. The preparation of monomers by Matsumoto et al. suggests that endo stereoisomers of the dicarboximides were used. Related work by Matsumoto is found in U.S. Pat. No. 4,039,491, e.g. in Example 20, where low molecular weight polymers of N-propyl norbornene dicarboximide were apparently obtained especially since polymerization was carried out in the presence of 1-hexene, a molecular weight limiting material.
High molecular weight polymers of N-phenyl norbornene dicarboximide are disclosed in my copending application Serial No. 07/067,562, filed Jun. 26, 1987 now abandoned.


A method is described for fabricating an arrangement where a connector (12, FIG. 1) lies on a circuit board (14) and contacts (26) have forward contact parts lying in passages (18) of the connector insulator (16) and board-received contact parts lying in interference fit in holes (24) of the circuit board, which facilitates replacement of a single damaged contact. An installing tool (70, FIG. 3) has channels (80) that receive the forward contact parts (40) and leave the board-received contact parts (32) projecting therefrom. The installing tool with contacts therein is moved towards the circuit board to press the projecting board-received parts of the contacts into the circuit board holes (24). The installing tool is then removed, leaving the contacts behind with their forward parts projecting up from the circuit board. The connector insulator (16, FIG. 4) is then moved so its passages receive the forward contact parts, the connector then being fastened to the circuit board. Because of the fact that the insulator does not press the contacts into place, there is no need for abutments on the insulator to engage shoulders on the contacts, and therefore an individual contact can be pulled forwardly out of the circuit board and connector.

One type of solderless connector termination system, includes contacts with forward parts lying in the connector insulator, and with board-received parts press fit into plated-through holes of a circuit board or the like. Solder is not used to hold and connect the board-received parts to the plated holes in the board, principally where the circuit board has ground planes and is thick and difficult to quickly heat. The system is assembled by first inserting the forward connector parts into the insulator passages. The insulator is pressed forcefully towards the circuit board to press the board-received parts into interference fit with the circuit board holes. It may be noted that other systems use solid board-received contact parts for press fit in the circuit board holes, although newer systems use more compliant board-received parts such as those with a slot resembling the eye of a needle.
In order for the insulator to press firmly against the contacts to press fit the board-received contact parts into the board holes, the insulator was formed with rearwardly-facing abutments that abutted forwardly-facing shoulders on the contacts. If a contact should become damaged, it was replaced by removing screws that held the connector to the circuit board, removing the connector insulator, replacing the damaged contact from the rear of the insulator, and reinstalling the connector insulator. Some systems use a group of connectors and various fastening devices that hold them in place. In that case, the removal of a single connector insulator to replace one or a few damaged contacts, takes considerable time. It would be desirable if a single contact could be replaced from the front or mating end of the connector without having to detach the connector from the circuit board or other device in which the contacts are press fit.

Repairable solderless connector arrangement


Ferromagnetic resonant devices include special coupling loops formed of multi-conductor transmission lines to increase the RF electromagnetic coupling to the ferromagnetic resonators, while decreasing coupling to spurious resonant modes.

1. Field
This invention relates to improvements in ferromagnetic filters and, in particular, to a method for increasing the bandwidth while reducing spurious responses in such filters.
2. Prior Art
A ferromagnetic filter in its rudimentary form, consist of a coupling loop positioned close to a sphere of a ferromagnetic material located in a magnetic field. The ferromagnetic material, usually yttrium-iron-garnet (YIG), can be made to produce a principal resonance at a frequency determined by the strength of the magnetic field. The resonant frequency is given by fo=.gamma.Ho where Fo is the resonant frequency, .gamma. is the gyromagnetic ratio, 2.8 MHz/oersteds, and Ho is the applied magnetic field in gauss.
Bandwidths of such devices are usually small, typically less than 35 MHz about the center frequency. Increasing the bandwidth of these filters has been a long-standing objective. In prior art approaches to produce wider bandwidths, the coupling between the loop and the sphere has been increased by bringing the loop closer to the sphere or a strap with lower inductance has been substituted for the more commonly used single wire loop. These approaches have resulted in an increase in both crossing and tracking spurious responses. Tracking spurious are spurious responses which follow the principal resonance of the sphere as it is tuned across a frequency range. Crossing spurious are those which do not tune at the same rate as the principal resonance mode and therefore cross through the principal resonance mode as it is tuned through a frequency range.
Prior approaches designed to reduce the spurious responses have included decreasing the unloaded Q of the YIG sphere by means of roughening the surface of the sphere; however, this process increases the insertion loss at the principal resonance.
There are a number of additional problems associated with prior art YIG filters which may be explained with reference to a rudimentary YIG filter, such as that shown in FIG. 4. In this Figure, an input port 401 is connected to an output port 402 by way of a coupling loop 403, which surrounds a YIG sphere 404. Note that in all figures, dots on a line about a YIG sphere represent the initiation or termination of a coupling loop. For example, in FIG. 4B, the dots represent the initiation and termination of loop 403. In the operation of this device, a signal placed on the input port is transmitted to the output port. Signals which are at the principal resonance of the sphere are rejected and returned to the input port. In this mode of operation, the device functions as a band-stop filter.
The length of the line from the input port to the output port forms an inductance that is an integral part of the band-stop filter. This inductance limits the range over which the band-stop filter can operate because it functions as a portion of a separate low-pass filter structure. Increasing the inductance reduces the high frequency cutoff of the low-pass filter which, in turn, limits the high frequency response of the YIG filter.
One prior art approach, intended to increase the bandwidth of the YIG filter at its principal resonance, is to lower the external Q of the sphere and loop by increasing the coupling between the two. This is done by increasing the turns of the coupling loops about the sphere. The disadvantage of this approach is it increases the series inductance of the line between the input and output ports and consequently reduces the high frequency cutoff off the low-pass filter section formed by this line.
The desirability of reducing the line inductance in band-stop filters has been generally recognized; however, it has not been as well recognized for bandpass filter. Attempts to reduce the line inductance by again substituting a wide strap for the usual single wire loop has resulted in the increases spurious response described previously. As an alternative to the strap, a number of parallel, closely spaced or touching wires has also been used with similar unsatisfactory results.
Practical prior art ferromagnetic resonator filters, which have been, for the most part, band-pass filters, usually make use of the same components described in connection with the band-stop filter of FIG. 4. That is, they make use of a coupling wire for coupling to the ferromagnetic material, which is typically in the shape of a sphere. The coupling wire is often formed into a loop around the sphere for increased coupling to the sphere. The coupling loops and spheres are housed in a structure which provides RF shielding between stages, but which allows the coupling wires to pass from stage to stage through the shield. A stage, as used herein is a basic filter section comprising for example one YIG sphere and its associated circuitry which is typically one or more coupling loops positioned about the sphere. In FIG. 2, loop 206 positioned about YIG sphere 201 comprise a first stage, loop 207 and sphere 202 comprise a second, and loop 208 and sphere 203 comprise a third.
Interstage coupling is accomplished with a wire with two loops formed along it, both ends of this wire being electrically connected to the RF housing or ground. Input and output coupling is accomplished with a wire loop connected from the input or output transmission line to the RF housing or ground. The coupling loops in each stage are positioned orthogonally with respect to one another to minimize coupling from one loop to another.
It is generally known that a band-pass filter can be designed by using input and output stage external Q and interstage coupling coefficients because the internal Q is relatively high in comparison to the Q of the external circuitry. The coupling values required are available from published tables and are related to the basic filter network. Thus, it is possible to attain the band-pass filter response desired from a ferromagnetic filter by adjusting the coupling loops close to the sphere, or by using a sphere which is large compared to the diameter of the coupling loop. Unfortunately, the spurious problem encountered with band-stop filters is present in band-pass filters as well. Both of these approaches to wide bandwidths lead to increased coupling to spurious modes. The spurious modes are undesirable in a band-pass filter because the tracking spurious modes produce additional passbands which degrades the filter out-of-band rejection and the crossing spurious modes produce additional passband insertion loss. Coupling to these spurious modes can be reduced by decreasing the unloaded Q of the ferromagnetic sphere, but this also causes increased passband insertion loss and a reduction in filter bandwidth. Thus, increased bandwidth in prior art devices results in degraded filter performance.

Multi-conductor ferromagnetic resonant coupling structure


A circuit package has been described for routing long traces between an electronic circuit, such as a phase locked loop, and external circuit components. The traces are routed through two substrates. In each substrate, the traces are routed primarily on a layer adjacent to and between a pair ground planes located close to the traces. Degassing apertures are located to the side of the long traces to avoid interfering with the shielding provided by the grounds planes. The circuit package uses two power plated through holes and two ground plated through holes to reduce the noise on the power supply lines. The circuit package also separates the signal carrying plated through holes from the power plated through holes, which reduces noise on the long traces. Noise is further reduced on the long traces by using the ground plated through holes to shield the signal carrying plated through holes from noise generated at the power plated through holes.

This invention relates to circuit packages, and more particularly, to circuit packages capable of reducing noise in electronic systems.
Noise can interfere with the operation of electronic systems by corrupting the signals in the systems. In complex electronic systems, such as processor systems, design choices can increase the susceptibility of signals in the system to corruption by noise. For example, increasing the length of a power-carrying conductor increases the susceptibility of a power signal to noise corruption. Since the power signal is coupled from the power-carrying conductors through transistors, resistors, capacitors, and other electronic components, noise on the power signal can be coupled to the signal-carrying conductors. Noise coupled to the signal carrying conductors may in turn corrupt signals on the signal-carrying conductors. For example, if a signal-carrying conductor carries a clock signal, then noise coupled to the signal-carrying conductor can corrupt the clock signal and cause inconsistent operation of any systems synchronized to the clock signal. It is therefore desirable to design electronic packaging to reduce the likelihood of corrupting power carrying conductors with noise.
A number of techniques for reducing the effects of noise in electronic systems are described in Noise Reduction Techniques in Electronic Systems, 2nd Edition, by Henry W. Ott. For example, Ott describes electromagnetic shielding packages and grounding structures that can be used to reduce noise in electronic systems. Unfortunately, these shielding packages and grounding structures and the general principles that underlie their operation are difficult to apply to complex electronic systems. The difficulty in applying these general principles to a complex electronic system increases as the number of substrates in the system increases, as the number of conductive layers in the substrates increases, as the number of signal and power carrying conductors increases, and as the frequency of any system clocks increases. The problem becomes especially difficult when long, power-carrying conductors are coupled to components external to a die. Such a problem arises in phase-locked loop circuits used in processors to generate a system clock. These circuits are often coupled by a long conductor to an external power supply filter located on a second level substrate.
For these and other reasons there is a need for the present invention.


A magnetometer is desclosed in which a gas cell containing atomic vapor is pulse pumped at one of the transitions of the gas in the cell. After the pulse has passed through the gas cell, thereby causing alignment of all the individual atomic moments along the propagation direction of the pulse, a probe beam reads out the Larmor precession frequency of the freely precessing atoms in terms of the frequency of the amplitude modulation of the probe beam caused by the free precession within the gas cell. The system is suitable for laboratory measurements of the absolute value of a magnetic field and for packaging in an expendable battery powered water-born buoy becuase of the low power consumption of the subject system.

The subject invention relates to improvements in the measurement of magnetic fields in terms of providing a new laboratory instrument and also in terms of providing a new magnetometer for antisubmarine warefare (ASW) applications in which individual magnetometers are carried by air-dropped or moored water-born buoys, which are distributed over a given area to monitor either subsurface or surface activity.
It is well known that submarines and surface ships alter the local magnetic fields in the vicinity of the ship. In prior art ASW surveillance systems, a so-called "point" magnetometer is carrie don a boom mounted aft of an aircraft and the aircraft executes a search pattern in search of changes of the local magnetic field which would indicate the presence of a submarine or a surface ship. It will be appreciated that in this mode of operation only one point immediately below the point magnetometer is searched at a time and that a submarine or surface ship may avoid detection simply by not being at the point searched at the time that the magnetometer is overflying the point.
Up to the present time, it has been inexpedient to provide water-born buoys with magnetometers due to a number of factors. The first factor which is almost determinative of the situation is the power drain when utilizing present day "point" magnetometers. The usual point magnetometer is the so called nuclear magnetic resonance (NMR) spectrometer or optically pumped magnetometer which involves the use of a continuous pumping beam and the use of an RF feedback for stimulating the natural precession of the magnetic moments or magnetic angular momentum vectors of atoms in a gas cell about a local magnetic field. The use of a continuous pumping beam of sufficient magnitude to stimulate the gas would run down currently available batteries utilized in water-born buoys in a matter of minutes, thereby precluding the use of this type of system in buoys whose life must be in excess of one hour.
Moreover, in nuclear magnetic resonance spectrometers there is a problem with the intensity stability of the source. It is well known that the presence of a continuous pumping beam actually shifts the atomic precession frequency away from the value which it would have had in the absence of this beam. Fluctuations in pumping light intensity translate into fluctuations in atomic precession frequency, which fluctuations are indistinguishable from those caused by changes in magnetic field strength. Great sensitivity in such a magnetometer therefore requires an extremely stable light source, and the construction of a light source of this type is quite costly. Moreover, the maintenance of a stable light source in a buoy environment is all but impossible.
An additional power draining feature in prior art systems is the feature which requires the generation of a periodic magnetic field in the RF region of the electromagnetic spectrum to stimulate the Larmor precession. Not only does this additional source draw energy from the battery continuously, but the RF field also affects the measurement in the same manner as the continuous pumping beam by engendering shifts in the atomic resonance frequency (Bloch-Siegert Shift). It will be appreciated that most previous optically pumped magnetometers have required the presence of the RF magnetic field to drive the atomic precession and thus render it susceptible to observation.
Moreover, the alignment of the RF field with the pumping beam axis is extremely critical. It will be appreciated that the maintenance of this alignment in a buoy application is difficult due to the shock experienced when the buoy hits the water.
While the above problems exist specifically with respect to the water-born buoy application mentioned above, laboratory instruments involving the use of NMR spectrometers also suffer from the effect of the continuous pumping beam on frequency and the effect of the RF field on the measurement being made.
The above problems are solved by the subject invention in which, in one embodiment, a circularly polarized "pulse" of light from a high intensity source such as a laser is projected through a gas cell, with the wavelength of the light corresponding to a predetermined transition of the gas. A relatively weak continuous probe beam at this transition is projected through the gas cell in a direction normal to the direction of propagation of the "pulse". After the passage of the pulse through the cell, due to the high intensity of the pulse the angular moments of large numbers of atoms line up in the direction of the propagation of the "pulse" and thereafter freely precess about the local magnetic field at the Larmor frequency. The free precession frequency, which is proportional to the local magnetic field, is then read out in terms of the frequency of the amplitude modulation of the probe beam caused by the rapid periodic population shifts between weakly and strongly absorbing magnetic sublevels of the atoms in the gas as the atoms precess.
The purpose of the pumping source is to pump up large numbers of atoms in the gas cell. Because of the high degree of polarization which can be obtained by a single pulse of the laser, free precession can be observed for a relatively long period of time before the signal has decayed to an unobserved level. Thus, no reinforcement of the free precession is necessary.
Once pumping is accomplished, pumping energy is no longer needed and is, in fact, undesirable. By using a pulse of pumping energy, instead of continuous illumination, the effect of the pumping beam on the measurement is eliminated because once the pulse exits the cell, it has no effect on the gas in the cell.
While it is true that the presence of the probe beam will tend to shift the atomic precession frequency, this beam is much less intense than the beam used for pumping and its effect is correspondingly reduced and made quite negligible. It will be appreciated that the gas utilized is desirably one which has a zero orbital angular momentum state (S state), containing one or several unpaired electrons. Alternatively, other states having unpaired electrons may be utilized.
The S state is desirable because of its zero orbital angular momentum, which relaxes or decays at a slower rate than do states having non-zero orbital angular momenta. It is a finding of this invention that the decay is sufficiently slow to permit observation of the free precession which is measured by the subject system.
The magnitude of the magnetic field at the gas cell is determined from the frequency of the amplitude modulation of the probe beam. The probe beam is modulated at the frequency, .omega., of the precessing atoms in the gas by a process involving population shifts between weakly and strongly absorbing angular momentum sublevels after pumping has occurred. As is generally understood, the periodic population shift takes place at the same frequency as that of the precession. In this case, "free precession" refers to the absence of any external reinforcement of the natural precession either by feedback loops or otherwise. It is a finding of this invention that when using a high energy pumping pulse no feedback or direct stimulus is necessary in order to read out the Larmor frequency of the freely precessing atoms. While absolute value of the magnetic field may be obtained from the subject apparatus, in ASW applications, changes in the magnetic field, dHdt, representative of a passing ship or submarine may be detected without the detection of the absolute value of the magnetic field.
As will be appreciated, the obtaining of free precession without RF feedback eliminates the need for a direct coupled alternating magnetic field, the power associated with the generation of the field and the frequency shift engendered by the use of such a field, as well as the problem of aligning the RF field coils.
Secondly, by the use of a pulsed source, the effect of the source on the measurement is completely eliminated as well as reducing the power requirements by eliminating the need for a continuous beam. The source is pulsed at a rate which, in general, will be much longer than the rate of Larmor precession for the particular gas and the expected magnetic field. In water-born buoy operation to conserve power the source may be pulsed at a rate as low as 5 times a second. Finally, the requirement for a stable source is eliminated because the pumping beam has no effect on the observed resonance frequency.
The subject system has unique application to water-born buoys outfitted with the subject magnetometer because of the low power drain and the relatively limited effect of the marine environment on this type of magnetometer. It will be appreciated that for ASW applications it is only the change in magnetic field due to the passage of a ship or submarine, as opposed to the absolute value of the magnetic field, which need be monitored. The motion of the buoy due to wave action or currents can be designed to be outside of the change in magnetic field value expected due to the passage of surface or surface vessels, even though the motion of the buoy would have an effect on measurement of the absolute value of earth's magnetic field at the buoy.
As a laboratory instrument, the subject magnetometer is easily controlled with stability and alignment being considerably less critical than in the prior art optically pumped magnetometers. Moreover, the pumping source may be a low power semiconductor laser or a multimode laser which emits a relatively broad spectrum of radiation, one peak of which will be at the appropriate transition of the atoms in the gas.
While most optically pumped magnetometers have utilized RF feedback at the Larmor frequency, as illustrated in U.S. Pat. No. 3,173,082 issued to W. E. Bell et al on Mar. 9, 1965, one embodiment of a magnetometer is described in the Bell et al patent in which a directly-coupled alternating magnetic field is not used. In Bell et al, embodiment of FIG. 1 a continuous source is modulated at .omega.=Larmor precession frequency to "reinforce" the natural precession and the field is read out as the absolute amplitude of the pumping beam rather than .omega..
In this embodiment of the Bell et al system, there is no free precession because the modulation of the pumping beam "reinforces" the precession. Moreover, there is no pulsed source, as in the subject system. The Bell et al source is continuous, and interaction with the gas is required, while in the subject system, care is taken to prevent interaction of the pumping beam and the gas once the precession phenomenon has been initiated as a result of the pumping.
Moreover, Bell et al do not use a separate probe beam and do not measure "modulation" of this probe beam. Bell et al do measure the modulation of the pumping beam (see FIGS. 5-7). However, in the embodiments of FIGS. 5-7 regenerative feedback is employed.
Thus, unlike the Bell et al system, the subject system is pulse pumped and does not depend on reinforced or stimulated precession in order to detect the atomic resonance precession frequency.
It is therefore an object of this invention to provide an improved magnetometer utilizing pulse pumping.
It is a further object of this invention to provide a magnetometer in which free precession is allowed to exist and from which a measurement of the local magnetic field is made.
It is another object of this invention to provide a magnetometer suitable for use in ASW applications either from moored buoys or from expendable airdropped buoys in which power drain and stability requirements are minimized.
It is another object of this invention to provide an improved ASW system utilizing a pulsed pumped magnetometer.
It is still further object of this invention to provide an improved ASW system utilizing a magnetometer operating on the principle of free precession.
It is a still further object of this invention to provide a low cost, easily fabricated magnetometer.
These and other objects will be better understood in conjunction with the following specification taken in conjunction with the drawings in which:


The present invention is directed to a method for hydroprocessing Fischer-Tropsch products. The invention in particular relates to an integrated method for producing liquid fuels from a hydrocarbon stream provided by Fischer-Tropsch synthesis. The method involves separating the Fischer-Tropsch products into a light fraction and a heavy fraction. The heavy fraction is subjected to hydrocracking conditions, preferably through multiple catalyst beds, to reduce the chain length. The products of the hydrocracking reaction following the last catalyst bed, optionally after a hydroisomerization step, are combined with the light fraction. The combined fractions are hydrotreated, and, optionally, hydroisomerized. The hydrotreatment conditions hydrogenate double bonds, reduce oxygenates to paraffins, and desulfurize and denitrify the products. Hydroisomerization converts at least a portion of the linear paraffins into isoparaffins.

The majority of combustible liquid fuel used in the world today is derived from crude oil. However, there are several limitations to using crude oil as a fuel source. For example, crude oil is in limited supply, it includes aromatic compounds believed to cause cancer, and contains sulfur and nitrogen-containing compounds that can adversely affect the environment.
Alternative sources for developing combustible liquid fuel are desirable. An abundant source is natural gas. The conversion of natural gas to combustible liquid fuel typically involves converting the natural gas, which is mostly methane, to synthesis gas, or syngas, which is a mixture of carbon monoxide and hydrogen. An advantage of using fuels prepared from syngas is that they typically do not contain appreciable amounts of nitrogen and sulfur and generally do not contain aromatic compounds. Accordingly, they have less health and environmental impact than conventional petroleum-based fuels. Fischer-Tropsch synthesis is a preferred means for converting syngas to higher molecular weight hydrocarbon products.
Fischer-Tropsch synthesis is often performed under conditions which produce a large quantity of C20+wax, which must be hydroprocessed to provide distillate fuels. Often, the wax is hydrocracked to reduce the chain length, and then hydrotreated to reduce oxygenates and olefins to paraffins. Although some catalysts have been developed with selectivity for longer chain hydrocarbons, the hydrocracking tends to reduce the chain length of all of the hydrocarbons in the feed. When the feed includes hydrocarbons that are already in a desired range, for example, the distillate fuel range, hydrocracking of these hydrocarbons is undesirable.
It would be advantageous to provide a method for hydroprocessing Fischer-Tropsch wax which minimizes the hydrocracking of hydrocarbons in the distillate fuel range. The present invention provides such methods.
The present invention is directed to a method for hydroprocessing Fischer-Tropsch products. The invention in particular relates to an integrated method for producing liquid fuels from a hydrocarbon stream provided by Fischer-Tropsch synthesis. The method involves separating the Fischer-Tropsch products into a light fraction with normal boiling points below 700xc2x0 F. and including predominantly C5-20 components and a heavy fraction with normal boiling points above 650xc2x0 F. and including predominantly C20+components. The heavy fraction is subjected to hydrocracking conditions, preferably through multiple catalyst beds, to reduce the chain length. The products of the hydrocracking reaction following the last hydrocracking catalyst bed, optionally after a hydroisomerization step, are combined with all or a portion of the light fraction. The combined fractions are hydrotreated, and, optionally, hydroisomerized. Hydrotreatment hydrogenates double bonds, reduces oxygenates to paraffins and desulfurizes and denitrifies the fractions. Hydroisomerization converts at least a portion of the linear paraffins into isoparaffins.
When the products of the hydrocracking reaction have passed through the last bed of hydrocracking catalyst, they are at a relatively elevated temperature. When these products are combined with the light fraction, the light fraction acts as a quench fluid, cooling the fraction, preferably to a desired temperature for performing the hydrotreatment step.
In one embodiment, the light fraction is introduced into a reactor at a level below the last hydrocracking catalyst bed and above or within a hydrotreatment bed. In this embodiment, the temperature and/or pressure of the hydrotreatment bed can be, and preferably are essentially the same as that in the hydrocracking bed(s). In another embodiment, the products from the hydrocracking reactor are pumped to a separate hydrotreatment reactor, where they are combined with the light fraction. In this embodiment, the temperature and or pressure of the hydrotreatment reactor can be, and preferably are different than that in the hydrocracking reactor.
The products from this xe2x80x9csplit-feedxe2x80x9d hydroprocessing reaction can be separated into at least a hydrogen-rich gas stream, a distillate product predominantly in the C5-20 range, and a bottoms stream. The bottoms stream can optionally be resubjected to the hydrocracking conditions to provide an additional light fraction, or used, for example, to prepare a lube base stock.
In one embodiment, the heavy fraction and/or the light fraction include hydrocarbons in the same range derived from other sources, for example, petroleum refining.

Method for upgrading Fischer-Tropsch wax using split-feed hydrocracking/hydrotreating


A laser probe for measuring apertures in a sheet of material has a laser beam and a detection system. The laser beam has a major axis and a minor axis which are orthogonal to each other. The major axis is much larger than the minor axis. The dimensions of the apertures are determined from the fraction of the laser beam which passes through the sheet of material. Slot widths are measured by identifying relatively constant amounts of light passing through the sheet as the sheet moves relative to the laser beam.

This invention relates to measuring the size of apertures in a material having an array of similarly sized apertures. Specifically, it relates to measuring the size of apertures in shadow masks for cathode-ray tubes.
Shadow masks are used in color display tubes to insure correct color reproduction of objects at the cathodoluminescent screen. One type of shadow mask is made of a thin metal sheet with substantially parallel columns of slots cut into it. The slots are separated within a column by a tie bar and typically have a rectangular shape with rounded ends. Adjoining columns of slots are offset from each other such that the center of the slot in one column is aligned with the center of the tie bar of the adjoining columns. Other shadow masks have other aperture shapes including: complete column apertures similar to the columns of slots except without the tie bars; and circular apertures arranged in columns and rows across the sheet of material.
To insure proper shadow mask quality, a number of techniques have been developed to measure the dimensions of these various apertures. In most methods, the apertures are measured by projecting a beam of light towards one side of the shadow mask and studying the transmitted light on the other side. In the prior art, the laser beam has always had a circular cross-section where it intersects the shadow mask. In some methods, this circular laser beam is made large enough to cover several apertures. Because the beam is so large, only average dimensions for large sections of the apertures can be attained from such systems. The large beam does not provide any detailed information about particular regions of a given aperture.
Another method uses a circular beam that is smaller than the smallest measurable dimension of a given aperture. This small beam is swept over the shadow mask in one direction as the shadow mask moves in a transverse direction. As the laser spot traverses the shadow mask, light sensors on the opposite side of the shadow mask measure the intensity of the transmitted light. In order to calculate a dimension of the aperture, this method divides the shadow mask into square segments with a plurality of square segments assigned to each aperture. To scan an entire aperture, the small beam must traverse the aperture several times while the mask moves in the transverse direction. After scanning a large block of square segments, the dimensions of each aperture can be determined by comparing the relative intensities of each square segment. This system requires both a large amount of memory to track the intensity at each square segment and the ability to uniformly scan the shadow mask.


A solid-state imaging device having a high resolution, comprises a plurality of pixels disposed in rows and columns each converting optical signals into signal charges; a vertical charge coupled device (CCD) register disposed between two pixel trains forming one group for transferring said signal charges; a first charge read-out element for reading out signal charges of each pixel disposed in one pixel train of two pixel trains and for transferring the signal charges to the vertical CCD register; a second charge read-out element for reading out signal charges of each pixel disposed in another pixel train of two pixel trains and for transferring the signal charges to the vertical CCD register; a charge storage element for separately storing signal charges which are separately transferred from respective pixel of each train of two pixel trains through the vertical CCD register; and a horizontal CCD register for transferring signal charges as one line unit, which are sequentially read out from the charge storage element in the order.

The present invention relates to a solid-state imaging device, and more particularly, to a solid-state imaging device of a high-resolution type which is used in broadcasting video cameras and capable of promoting the high integration of elements in photosensitive region.
FIG. I shows an example of a construction of a conventional solid-state imaging device of a high resolution type which is used in broadcasting video cameras. The solid-state imaging device comprises a plurality of pixels 1 which are disposed in rows and columns, respectively, and for storing signal charges which are generated by light reception, vertical CCD (charge coupled device) registers 2 for transferring the signal charges which are generated and stored in the pixels 1, storage registers 3 which are disposed under the vertical CCD registers 2 and temporarily storing the signal charges, a horizontal CCD register 4 which is disposed near an undermost portion of the storage registers 3 and for transferring signal charges of one pixel line, and an output circuit 5 for externally outputting a voltage which is converted from the signal charges transferred from .the horizontal CCD register 4. The solid-state imaging device is called an FIT (frame interline transfer) type which is well known from our prior Japanese application (see Japanese Patent official gazette of Laid-open Publication No. 55-52675-1980-).
Since a solid-state imaging device of the FIT type has the storage registers 3, this type device can increase a transfer speed of the vertical CCD register 2 in comparison with the further conventional solid-state imaging device of a conventional interline type, so that it is possible to have extremely improved smear characteristics. Accordingly, this type of device is used in broadcasting video cameras and certain types of personal use cameras.
In this conventional solid-state imaging device, one unit cell has pixels 1, charge read-out regions 6, vertical CCD register 2, and an element separating region 7, as shown in FIG. 2, and a pitch P.sub.H in the horizontal direction is the sum of widths of the pixel 1, the register 2 and the distances between pixels 1 and register 2. Namely, the pitch P.sub.H is represented by the equation of "P.sub.H =L.sub.1 +L.sub.2 +L.sub.3 +L.sub.4 ".
Furthermore, a pitch P.sub.V in the vertical direction is the sum of the widths W.sub.1 and W.sub.2 of the pixel 1 and the element separating region. That is, the pitch P.sub.V is represented by the equation of "P.sub.V =W.sub.1 +W.sub.2 ".
As understood from the construction shown in FIG. 2, the pitch size in the horizontal direction is substantially the same as the size in the vertical direction in spite of providing the charge read-out region 6 between the pixel 1 and the vertical CCD register 2. Accordingly, it is difficult to integrate the circuit in the horizontal direction, so that the pitch size in the horizontal direction determines the upper limit o the number of the pixels. In accordance with increased pixels in the future, a high integration in the horizontal direction is required by means of the increase of the pixels in the horizontal direction because it is impossible to increase the pixel number in the vertical direction which is determined by the number of the horizontal scanning lines such as 525 lines in an NTSC system, 1125 lines in a high-vision and the like. However, high integration in the horizontal direction is difficult in comparison the high integration in the vertical direction as described above, and becomes a problem in that forcible integration results in the deterioration of the smear characteristics and sensitivity.

Solid-state imaging device having signal transferring groups formed of a CCD register and two pixel trains