Methods for retrofitting a turbomachine are provided. A first trip cup of the turbomachine may be replaced with a second trip cup. The first trip cup may include a throw-out arm connected to a first trip cup spring. The second trip cup may include a plunger disposed in a hole defined by the second trip cup and a plunger spring encircling the plunger in the hole. The first trip cup may be removed from the turbomachine and the second trip cup installed such that a location of the plunger in the turbomachine is the same as a location of the throw-out arm in the turbomachine when the first trip cup was installed on the turbomachine. The tension in the plunger spring may be adjusted such that, when a speed of the turbomachine exceeds a predetermined value, the plunger actuates a trip paddle located adjacent the second trip cup.

Conventional steam turbines, for example, the Worthington single stage steam turbines, may use a trip cup (alternatively, referred to as a trip disk) having a throw out arm for shutting off a steam source supplying steam to the steam turbine when the steam turbine speed (generally measured in revolutions per minute (RPM)) exceeds a certain predetermined value, and a mechanical flyweight style governor for varying (increasing or decreasing) an amount of steam supplied from the steam source to the steam turbine to adjust (increase or decrease) the speed of the steam turbine as long as the predetermined value is not exceeded. The predetermined value indicates that the steam turbine is operating at overspeed. Overspeed refers to a condition in which the steam turbine runs at a speed beyond its design limit. For instance, the steam turbine may overspeed when there is no or little load while power is applied or when the governor malfunctions.
FIG. 1 illustrates a cross-sectional overview of a conventional steam turbine 100 including a trip cup 102 and a mechanical flyweight style governor 104. The trip cup 102 and the mechanical flyweight style governor 104 are enclosed in a housing 108. The trip cup 102 is connected to the shaft 110 of the steam turbine 100 and rotates with the shaft 110. The mechanical flyweight style governor 104 is connected to the shaft 110 and is also connected to a steam source 116 (FIG. 1C) via a system of governor linkages 106. The mechanical flyweight style governor 104 moves the governor linkages 106 based on the speed of the steam turbine 100. The motion of the governor linkages 106 varies the steam supplied from the steam source 116 to the steam turbine 100 and, in turn, adjusts the speed of the steam turbine 100. In this manner, the operating speed of the steam turbine 100 is maintained.
FIG. 1A illustrates an enlarged cross-sectional view of the trip cup 102 and the mechanical flyweight style governor 104 of the conventional steam turbine 100 of FIG. 1. The mechanical flyweight style governor 104 includes a coil spring 1041 surrounding the shaft 110 and two governor flyweights 1042 disposed adjacent the coil spring 1041. The coil spring 1041 is positioned between the two governor flyweights 1042 at an inner end (closer to the trip cup 102) of the coil spring 1041 and an outer collar 1043 at an outer end (farther from the trip cup 102) of the coil spring 1041. The two governor flyweights 1042 are disposed surrounding the shaft 110. The two governor flyweights 1042 are connected to the shaft 110 adjacent the inner end of the coil spring 1041. The two governor flyweights 1042 rotate with the shaft 110 and at the speed of the shaft 110. The outer collar 1043 is connected to the governor linkages 106 such that a compression of the coil spring 1041 moves the governor linkages 106. During operation, a centrifugal force acts on the two governor flyweights 1042 causing the two governor flyweights 1042 to move outward and away from the coil spring 1041. This action of the two governor flyweights 1042 compresses the coil spring 1041 and moves the governor linkages 106. The motion of the governor linkages 106 adjusts the amount of steam output from the steam source 116 to the steam turbine 100 to adjust the speed of the steam turbine 100.
FIG. 1B illustrates a cross-sectional view of the trip cup 102 taken along the line 1B-1B in FIG. 1A. The trip cup 102 defines an opening 1022 through which the shaft 110 of the steam turbine 100 extends. A partially drilled hole 1023 is defined by the body 1021 of the trip cup 102. The partially drilled hole 1023 extends radially inwards from an outer circumferential surface of the body 1021 toward the central axis of the trip cup 102. The partially drilled hole 1023 houses a weight spring 1024 disposed therein and connected to a first end 1027 of the throw out arm 1025. The throw out arm 1025 is located in a recess 1026 in the trip cup 102 and a second end 1028 of the throw out arm 1025 is connected to the trip cup 102. The tension in the weight spring 1024 is adjusted such that, when the rotational speed of the steam turbine 100 exceeds the predetermined value, the throw out arm 1025 flies out from the trip cup 102. This results in a tripping action, commonly referred to as a "trip," wherein the throw out arm 1025 deflects a trip paddle 112 (FIG. 1D) disposed adjacent the trip cup 102. Due to the deflection of the trip paddle 112, trip linkages 1029 (FIG. 1D) in contact with the trip paddle 112 are actuated, for example, released. Releasing the trip linkages 1029 shuts off the steam supplied to the steam turbine 100, thereby shutting off the steam turbine 100. In this manner, the steam turbine 100 is prevented from operating at overspeed.
FIG. 1C is a perspective view of the conventional steam turbine 100 of FIG. 1. Illustrated in FIG. 1 are the housing 108, the governor linkages 106, and the steam source 116. FIG. 1D is a top plan view of the trip cup 102 and the mechanical flyweight style governor 104 of the conventional steam turbine 100 of FIG. 1 contained in the housing 108. Also shown are the partially drilled hole 1023, the recess 1026, trip paddle 112, and the trip linkages 1029 connected to the steam source 116.
It has been found by those of ordinary skill in the art that the trip cup 102 may present a number of drawbacks. For example, the weight spring 1024 attached to the throw out arm 1025 may exhibit erratic behavior. As a result, sometimes the trip occurs prematurely, or sometimes the trip occurs too late. In addition, the throw out arm 1025 may break, thereby requiring replacement.
What is needed, therefore, is a steam turbine overspeed control system that provides reliable and efficient operation, requires low maintenance with ease of assembly and disassembly, and fits in the footprint of the existing trip cup.


The installation for cleaning the zone near the drill hole contains a hollow body (1) in which is arranged a subassembly for generating hydrodynamic waves that is designed in the form of a turbulence chamber (3) that has, arranged tangentially in its upper part, entry channels (4) with which the subassembly is connected to the cavity of the body (1). The outlet channel (5) of the turbulence chamber (3) is designed with a conical taper.

There is a known installation for cleaning the zone near the drill hole (S.M. Godiev "Inspolzovanie vibratsii v. dobyche nefti" (Utilization of vibrations in petroleum conveying), 1977, "Nedra" editions (Moscow), p. 50, FIG. 27) that contains a hollow body with a subassembly arranged in it for generating hydrodynamic waves. This subassembly constitutes a case housed in the body at minimal distances from its walls. The case is arranged rotatable around its axis in rolling bearings. There are openings on the walls of the body and the case that serve as channels for the liquid to pass through. The body has radial outlet channels and the case has tangential outlet channels. To prevent leakage of the liquid through the annular gap, a sleeve seal is arranged in the upper part between the body and the case. The outlet channels of the case and the body are on the same level.
The installation with ascending pipes is lowered into a drill hole until reaching the level of the arrangement of perforation openings. A working fluid is pressed in through the ascending pipes. By coming into the cavity of the case, the liquid also flows into the tangentially arranged outlet channels of the case. The liquid flows out of the outlet channels into the radial channels of the body and from there into the torus of the drill hole.
If the liquid flows out through the tangential channels of the case at a high velocity, a reaction torque is created at the case, whereby it is made to rotate around the body. In this process, the channels of the case and the body are periodically closed and opened with a certain frequency. Hydrodynamic liquid pulsations are created by the periodic covering of the channels in the zone near the drill hole. The amplitude and frequency of the hydrodynamic pulsations depend on the pressure of the liquid being flushed and the frequency of rotation of the case around the body.
Due to their insufficient strength, the hydrodynamic pulsations created do not contribute to the destruction of various deposits on the drill hole walls and do not provide for cleaning of the clogged pore channels of a petroleum-yielding seam.
Furthermore, the known installation has a complicated construction, which increases its production costs and reduces its operating reliability, while the presence of the moving subassemblies and parts in the construction leads to its intensive mechanical wear and reduces the service life of the installation.
All of this means that the known installations do not ensure an effective cleaning of the zone near the drill hole and do not promote an increase in productivity of a drill hole or in petroleum yield of a seam.

Installation for cleaning the zone near the drill hole


A remarkably low odor carbonless paper solvent is provided comprising a mixture of diisopropylbiphenyl and triisopropylbiphenyl, generally in an amount of 50 to 90% by weight diisopropylbiphenyl and 10 to 40% by weight triisopropylbiphenyl. The solvent and a chromogenic substance such as a leuco dye are encapsulated to form microcapsules which are coated onto one surface of a carrier sheet. A color developing substance is then applied to another sheet to form a carbonless marking system. When the microcapsules are ruptured, the solubilized chromogenic substance contacts and reacts with the developer to form an image.

This invention relates in general to solvents for use in solubilizing dyes and, more particularly, to solvents used in the production of carbonless paper, microcapsules containing a chromogenic compound solubilized by such solvents, and pressure sensitive marking and recording material coated with such microcapsules.
Carbonless paper and other marking systems depend upon localized contact between a chromogenic compound such as a leuco dye and a color developing substance to produce a visible indicia. In such marking systems, the dye is solubilized in a solvent and the dye and solvent are then emulsified in an aqueous solution to form tiny "oil" droplets. The oil droplets are then encapsulated by the polymerization or coagulation of a suitable material to form a wall around the individual droplets.
In one application, the microcapsules which are formed can be coated on the back side of a sheet of paper or other material to form a coated back sheet. A second sheet of paper is then coated on the front side with a color developing substance, typically a proton donating component such an acidic clay or phenolic resin. The microcapsule outer walls isolate the dye from the developer until the microcapsules are ruptured by the application of localized pressure. When pressure is applied by a stylus, pen, typewriter, printer or similar instrument, the microcapsules burst and the oil solution containing the solubilized dye is released and is transferred to the second sheet of paper where the dye reacts with the acid component to form an image. Carbonless paper systems of this type are described in U.S. Pat. Nos. 3,418,656 and 3,418,250, which are incorporated by reference herein in their entirety.
Solvents which are utilized in carbonless paper systems should be capable of solubilizing the leuco dye, have a low water solubility, a viscosity which is low enough to permit the microcapsule contents to be rapidly transferred to the developer upon rupture of the microcapsule, a low or negligible odor, low volatility to reduce evaporation during processing, low toxicity, negligible health risks, and low cost. Various solvents have been identified which satisfy many of the above requirements.
The suitability of particular carbonless paper solvents is dependent upon the characteristics of the particular dyes and developers utilized. For example, a low viscosity solvent is generally required when phenolic acid developers are utilized in order to achieve rapid image development. By contrast, when using an acid clay developer, a higher viscosity solvent can be used with acceptable results.
The presence of diisopropylbiphenyl and triisopropyl-biphenyl as impurities in a solvent comprising primarily mono-isopropylbiphenyl was disclosed in U.S. Pat. No. 3,627,581 to Phillips. In that patent, it was disclosed that a mixture of isopropylbiphenyl positional isomers provides better fad resistance and print intensities in comparison to higher alkylated biphenyls such as butylbiphenyl, amylbiphenyl, hexylbiphenyl, decylbiphenyl, diisopropylbiphenyl, and triisopropylbiphenyl. It was further disclosed that a certain amount of the higher alkylated biphenyl impurities could be tolerated in the isopropylbiphenyl isomer mixture. However, when the impurities are polyisopropylbiphenyls, namely diisopropylbiphenyl with trace amounts of triisopropylbiphenyl, it was taught that they should comprise no more than 55% by weight of the total biaryl content of the solvent.
Alkylated biphenyls having up to 24 carbon atoms in the substituent alkyl groups were identified as carbonless paper solvents in U.K. Patent Publication No. 1,352,597. Diisopropylbiphenyl was specifically identified as a suitable solvent in that patent.
The use of diisopropylbiphenyl as a component in a carbonless paper solvent was also disclosed in U.S. Pat. No. 4,774,136 to Okada et al. In that patent it was disclosed that diisopropylbiphenyl could be used to prevent the crystallization of p-monoisopropylbiphenyl at low temperatures. The solvent mixture consisted essentially of (i) 30 to 80% by weight of p-monoisopropylbiphenyl or a biphenyl mixture of not less than 80% by weight of p-monoisopropylbiphenyl, not more than 20% by weight of m-monoisopropylbiphenyl and not more than 10% by weight of diisopropylbiphenyl, and (ii) 70 to 20% by weight of diisopropylnaphthalene or a specified naphthalene mixture.
A carbonless paper solvent comprising diisopropylbiphenyl and minor amounts of triisopropylbiphenyl is commercially available from Koch Chemical Company under the trademark Sure-Sol 330. The solvent comprises approximately 81.6% by weight of a mixture of diisopropylbiphenyl positional isomers and 2.3% by weight of a mixture of triisopropylbiphenyl positional isomers.
While the suitability of diisopropylbiphenyl as both a minor and a major component of a carbonless paper solvent has been recognized in the patents and commercial product discussed above, the use of triisopropylbiphenyl as other than a trace component of such a solvent has not previously been disclosed.

Carbonless paper solvent comprising diisopropylbiphenyl and triisopropylbiphenyl and products utilizing same


The present invention relates to an electron microscope plasma cleaner for cleaning an electron microscope by using plasma, the cleaner including a vacuum chamber in which the sample is disposed; an electron gun for producing the electron beam and outputting the produced electron beam to the sample; an electron lens for magnifying the electron beam transmitting the sample and projecting the electron beam onto a fluorescent screen; a radio frequency controller for producing a first signal having radio frequency within a given range; and a plasma head for producing the plasma, receiving the first signal from the radio frequency controller, producing activated oxygen radicals and ions by using the plasma and the first signal, and supplying the activated oxygen radicals and ions to the interior of the vacuum chamber.

1. Field of the Invention
The present invention relates to an electron microscope plasma cleaner that has a triple plasma electrode and a multi gas injection nozzle, thus achieving the effective generation of plasma, and more particularly, to an electron microscope plasma cleaner that cleans the interior of a chamber of an electron microscope and the surface of a sample of the electron microscope with the radicals and ions produced by means of plasma, thus achieving the improvements in high resolution image observation and precision length measurement of the electrode microscope and the pattern distortion and damage of the image observed through the electrode microscope.
2. Background of the Related Art
An electron microscopes, which collects an electron beam and produces a focus thereon to observe and analyze the surface and interior of a sample, includes a scanning electron microscope (SEM), a critical dimension-scanning electron microscope (CD-SEM), a transmission electron microscope (TEM), dual beam (SEM+FIB (focused ion beam)), a nano prober and so on.
The electron microscope is a device that produces a high density electron current from an electron gun, collects an electron beam in an electron column, forms a focus thereon, radiates the electron beam onto a local observation point of a sample to be analyzed, produces and detects a signal, and magnifies (tens to millions of times) the image on the surface and interior of the sample.
With the development of nano technology, the electron microscope becomes necessary equipment for research, manufacturing process and quality management in all kinds of industrial fields like semiconductors, advanced materials, displays and so on.
On the other hand, cleaning organics and native oxide existing on the interior of a vacuum chamber of the electron microscope and the surface of a sample becomes a serious problem.
That is, the contamination caused by the organics on the vacuum chamber of the electron microscope and the surface of the sample gives bad interference in the observation of the image of the electron microscope, thus undesirably causing the contamination and deformation of the observed region and providing main interference in the spatial resolution like noise increment of the image.
The contamination on the vacuum chamber of the electron microscope is caused by the outgas from a photo resist as a main material of a semiconductor process and an organic material having high permittivity and weak bonding characteristics.
Further, the contamination of the vacuum chamber is caused by the contaminants of various structures (a sample stage, a sample holder and so on) of the vacuum chamber and the out-gas from grease.
Such organics have heavy mass and low motion energy, and accordingly, since most of organics are not pumped by means of a vacuum pump, they are absorbed/desorbed in the vacuum chamber and randomly move to collide against the beam incident thereon, thus being positively ionized. Further, the positive ions are deposited onto the area of the sample to which the electron beam is radiated having high negative charges therearound to form a black organic ion deposited film, which decreases the resolution of the image or deforming the observed pattern, thus making it hard to achieve accurate observation or fine measurement.
Further, the contamination of the organics on the surface of the sample is caused by various kinds of chemicals used for making the sample, residues reacting to the chemicals, water remaining after washing, and oil and water of a user′ body.
When the sample is kept in the air, further, native oxide is formed thereon to cause the surface of the sample to be contaminated.
If the contaminated sample is introduced into the sample chamber to observe the image of the electron microscope, the pattern distortion and the reduction of resolution of the observed image may become serious.
So as to solve the above-mentioned problems, accordingly, there is a definite need for the development of a new electron microscope plasma cleaner.

Hitachi High-Technologies Korea Co., Ltd.


A sample of a sample rack is sampled at analyzing units in the middle of a transfer line. A standby unit and a rack collecting unit are arranged near an exit of the transfer line. After sample, sampleracks are sorted out to the standby unit or the rack collecting unit at a first switching unit. The racks contained in the standby unit are sorted out to a returning line or the rack collecting unit in a second switching unit corresponding to a judged result of whether or not reexamination is required.

The present invention relates to automatic analysis apparatus, and more particularly to an automatic analysis apparatus in which a sample is pipetted from a sample container contained in a sample rack, and the sample is reexamined if necessary.
An automatic analysis apparatus for clinical inspection automatically performs analysis and inspection on analyzing items such as bilirubin, protein, GOT, GPT and the like for a sample such as blood, serum, blood plasma, urine and other body liquids. The automatic analysis apparatus has an analyzing unit for measuring a reaction liquid obtained by reacting a sample with a reagent. As to the methods of supplying the sample to the analyzing unit, there are a method in which a plurality of sample containers are mounted on a turntable and each of the sample containers is positioned at a sample pipetting position by intermittently rotating the turntable, and a method in which a sample rack containing sample containers is positioned at a sample pipetting position of an analyzing unit through a transfer line.
An example of the automatic analysis apparatus in which a sample rack is transferred through a transfer line is disclosed, for example, in Japanese Patent Application Laid-Open No. 4-65676 or in Japanese Patent Application Laid-Open No. 6-207943.
The automatic analysis apparatus disclosed in Japanese Patent Application Laid-Open No. 4-65676 is constructed such that a transfer line for transferring a sample rack in one direction and a transfer line for transferring a sample rack in the other direction are arranged in parallel, a sample rack supplied from a rack supply unit is transferred by the transfer line, a sample on the sample rack is pipetted to the analyzing unit at a sample sucking position provided on the transfer line, and the sample rack is placed in a rack collecting unit through the returning line after sampling. Further, in some midpoint of the returning line there is provided a rack standby space for keeping a reference sample for accuracy management on standby. The reference sample rack is periodically transmitted to the transfer line, and the sample rack is returned again to the rack standby by space through the returning line after sampling.
On the other hand, the analysis apparatus disclosed in Japanese Patent Application Laid-Open No. 6-207943 is constructed such that a standby unit for a sample rack is provided near a rack supply unit, a sample rack supplied from the rack supply unit is transferred by a transfer line, a sample is pipetted from the sample rack to the analyzing unit on the transfer line, and the sample rack is transferred to an exit of the returning line after sampling through the returning line. Further, sample racks having a probability of being reexamined are transferred from an exit of the returning line to the standby unit using a robot-hand, and sample racks not having a probability of being reexamined are transferred from the exit of the returning line to a rack collecting unit using the robot-hand. When an instruction of reexamination is made to a sample rack on standby in the standby unit, the corresponding sample rack is transferred to an entrance of a transfer line and pipetting of a sample to be reexamined is performed on the transfer line.
Both of the analysis apparatuses of the prior art disclosed in Japanese Patent Application Laid-Open No. 4-65676 and in Japanese Patent Application Laid-Open No. 6-207943 are constructed such that all the sample racks transferred by the transfer line are transferred through the returning line, and then contained in the standby unit or in the collecting unit.
In the practical work of sampling inspections, the in number of sample racks for general samples which are judged to need to be reexamined is less than the number of sample racks which are judged not to need to be reexamined; therefore, it can be said that a large number of sample racks which may be judged not to need be reexamined are transferred through the returning line.
When the above-mentioned prior art is applied to an automatic analysis apparatus so as to have a reexamination function for general samples, there occurs a problem in that a large number of sample racks are gathered at the exit of the returning line and a complex handling mechanism for solving the problem is required.


To provide a method of separating a pellicle and a device for separating a pellicle which can reduce the amount of residue left on an exposure original plate when the pellicle is separated from the exposure original plate and which can wash again the exposure original plate under mitigated washing conditions, a pellicle frame support pin is inserted into a jig hole provided in an outer surface of the pellicle frame, the pellicle frame support pin is moved in a direction in which the pellicle is separated from the exposure original plate, a separation force applied by the movement to the pellicle frame support pin is measured and the pellicle is separated from the exposure original plate while control is being performed such that the separation force is minimized.

In manufacturing semiconductor such as LSI, VLSI or the like, or in manufacturing a liquid crystal display board or the like, an exposure original plate is overlaid on a resist coated surface of a semiconductor wafer or a liquid crystal substrate, and a latent image pattern is formed on the resist by irradiating collimated light. At this time, when dust is adhered to the exposure original plate, the dust absorbs or bents the light causing deformation of a transferred pattern, roughen edges and black stains on a base, with the result that dimensions, quality, appearance and the like are disadvantageously degraded. It is noted that in the present invention, the "exposure original plate" collectively refers to a lithography mask and a reticle.
Hence, although a lithography operation is generally performed in a clean room, since it is difficult to constantly keep the exposure original plate clean, a method is adopted of adhering a pellicle which includes a pellicle film that is used as a dust fender on the pattern surface of the exposure original plate and that fully passes through the exposure light.
The pellicle is a dustproof protective cover for an exposure original plate which includes a pellicle frame (frame member), a pellicle film which is provided in a tensioned state on the upper end surface of the pellicle frame, an adhesive layer which is provided on the lower end surface of the pellicle frame and a liner which is intended for the protection of the adhesive layer, and the adhesive layer is stuck to the pattern surface of the exposure original plate.
When the pellicle is stuck to the pattern surface of the exposure original plate, the pellicle is located so as to surround a pattern region, and the pattern region and the outside of the pellicle are separated in the direction of thickness such that dust outside the pellicle is prevented from being adhered, with the result that the dust is not directly adhered on the surface of the exposure original plate but is adhered on the pellicle film. The dust on the pellicle film is not related to transfer as long as a focal point is located on the pattern of the exposure original plate at the time of lithography.
The pellicle is generally stuck to the exposure original plate with a dedicated device or a jig. In any device, a basic operation is the same, and a mutual position relationship between the pellicle and the exposure original plate is adjusted, the pellicle frame is thereafter pressurized parallel to the exposure original plate for a fixed time and thus the pellicle is stuck.
Incidentally, in recent years, as in the design rule of LSI, line widths have been progressively refined to a sub-quarter micron, wavelengths in exposure light sources have been progressively reduced. Specifically, the emission spectra of mercury lamps such as a g-line (436 nm) and an i-line (365 nm) which have so far been the mainstream are being shifted to KrF excimer laser (248 nm), ArF excimer laser (193 nm), F2 laser (157 nm) and the like. As a result of line widths being progressively reduced, an allowable size of a foreign substance and a haze (Haze: diffusion cloud value) that may occur on the pattern surface of an exposure original plate to which a pellicle is stuck is reduced.
As a film of a mask substrate which has been used in recent years, in order to cope with the refinement of the design rule, a phase-shifting film generally tends to be adopted in a phase-shifting mask (PSM: Phase-Shifting Mask). The phase-shifting film is significantly delicate, and thus the phase-shifting film may be damaged by excessive mask washing. It is noted that the phase-shifting mask is an exposure original plate in which, by addition of the phase-shifting film, the phase and transmittance of light passing through the phase-shifting film are controlled so as to improve a resolution and a depth of focus (DOF: Depth of Focus) at the time of exposure of a wafer and in which thus a transfer property is enhanced.
When a foreign substance or a haze occurs or a pellicle film is damaged for any reason, if a pellicle after being stuck to an exposure original plate needs to be replaced, the pellicle needs to be separated. Then, an operation called re-pellicle is needed in which the exposure original plate where the pellicle is separated is washed again, and in which a new pellicle is stuck.
In the separation of the pellicle, a method of carefully separating the pellicle while holding the pellicle with a hand has been mainly performed. Disadvantageously, however, there is a great danger that a photomask is damaged, and workability is significantly poor.
Hence, as a method of separating the pellicle with a separation jig, a method is proposed in which a pin-shaped separation jig is inserted into a round hole provided in a outer surface of a pellicle frame so as to lift the pellicle frame, and in which thus the pellicle is separated (IP Publication 1).

Method of separating pellicle and device for separating pellicle


An integrated circuit (IC) chip having circuitry adapted to detect and unlatch a latched transistor, and methods for operating the same are provided. In one example, an IC chip includes a body, a power rail disposed in the body and coupled to at least one of a plurality of contact pads disposed on the body, and a first core circuit disposed in the body. The first core circuit includes a first current limiting circuit, a silicon controlled rectifier (SCR) device having a first transistor, a second transistor, and a first latch sensing circuit. The first current limiting circuit is coupled to the power rail. First terminals of the first and second transistors are coupled to the first current limiting circuit. The first latch sensing circuit has a first input terminal coupled to second terminals of the first and second transistors. The first latch sensing circuit also has an output terminal coupled to the first current limiting circuit.

Single event latch-up (SEL) is generally an abnormal high-current state in a device caused by the passage of an energetic particle through sensitive regions of the device structure. SEL can result in the loss of device functionality. In complementary device structures in integrated circuits (such as in complementary metal-oxide-semiconductor (CMOS) structures), SEL can result in a parasitic silicon controlled rectifier (SCR) structure turning on to conduct a current. When the parasitic SCR structure is turned on, a voltage drop across the parasitic SCR structure can result in the parasitic SCR structure continuing to conduct the current. The continuous conduction of the current can damage the integrated circuit, such as by generating heat that can cause melting of components, migration of metal, or other problems.
The conventional approach for un-latching transistors in an integrated circuit (IC) die experiencing an SEL event is to reduce voltage applied across the SCR structure to a voltage low enough such that the latch-up can no longer be sustained and the high current disappear. The voltage applied across the SCR structure is typically reduced by removing power applied to the die or switching off the supply power within the IC die. However, removing power from the IC die causes the IC die to loose functionality until the power is restored. Additionally, memory states may be lost when the die is powered off.
Thus, there is a need for an improved structure and methodology for detecting and mitigating SEL events on integrated circuits.

Single event latch-up (SEL) mitigation detect and mitigation


The microwave frequency chip resistor assembly is used as a terminating device for a video jack. Such an assembly minimizes inductance variation and eliminate soldering associated with conventional metal film resistors.

1. Field of the Invention
The present invention is directed to a microwave frequency chip resistor assembly and, more specifically, to a chip resistor for terminating unused transmission lines to avoid interference with other signals.
2. Description of Related Art
As the TV industry uses more and more Serial Digital Data Signals for transmitting Television Signals and moves closer to a practical HDTV system, unterminated transmission lines must be terminated or risk interfering with other signals in the system.
Video jacks are commonly used switches in television studio master control rooms and editing suites. With the advent of Serial Digital techniques, unused signals in the switches must be terminated or risk interfering with the other transmission lines within the jack due to the high data rates. Conventionally, standard metal film resistors have been used as the terminating device.
In order to minimize reflections, the standard metal film resistor is soldered into a cylindrical housing of dimensions that provide a matched impedance (typically 75 ohms). As shown in FIG. 1, standard metal film resistor A is soldered in place at points B and C within housing D. This assembly is then installed in the video jack. A problem occurs because at microwave frequencies of 1 Ghz and above, variations in the reactance of the standard metal film resistor are significant. Typical metal film resistors are laser trimmed by etching a spiral groove in the body of the resistor to achieve a desired resistance. This causes variation in inductance due to the laser trimming and results in a need to vary the housing dimensions.
Additionally, soldering is a time-consuming operation that requires skilled operators, and the process requires cleaning of the assembly after the soldering process. Also, the variation of inductance in the metal film resistor causes unreliable microwave performance.

Microwave frequency chip resistor assembly


Generalized learning rules may be implemented. A framework may be used to enable adaptive spiking neuron signal processing system to flexibly combine different learning rules (supervised, unsupervised, reinforcement learning) with different methods (online or batch learning). The generalized learning framework may employ time-averaged performance function as the learning measure thereby enabling modular architecture where learning tasks are separated from control tasks, so that changes in one of the modules do not necessitate changes within the other. Separation of learning tasks from the control tasks implementations may allow dynamic reconfiguration of the learning block in response to a task change or learning method change in real time. The generalized spiking neuron learning apparatus may be capable of implementing several learning rules concurrently based on the desired control application and without requiring users to explicitly identify the required learning rule composition for that task.

1. Field of the Disclosure
The present disclosure relates to implementing generalized learning rules in stochastic spiking neuron systems.
2. Description of Related Art
Adaptive signal processing systems are well known in the arts of computerized control and information processing. One typical configuration of an adaptive system of prior art is shown in FIG. 1. The system 100 may be capable of changing or "learning" its internal parameters based on the input 102, output 104 signals, and/or an external influence 106. The system 100 may be commonly described using a function 110 that depends (including probabilistic dependence) on the history of inputs and outputs of the system and/or on some external signal r that is related to the inputs and outputs. The function F(x,y,r) may be referred to as a "performance function". The purpose of adaptation (or learning) may be to optimize the input-output transformation according to some criteria, where learning is described as minimization of an average value of the performance function F.
Although there are numerous models of adaptive systems, these typically implement a specific set of learning rules (e.g., supervised, unsupervised, reinforcement). Supervised learning may be the machine learning task of inferring a function from supervised (labeled) training data. Reinforcement learning may refer to an area of machine learning concerned with how an agent ought to take actions in an environment so as to maximize some notion of reward (e.g., immediate or cumulative). Unsupervised learning may refer to the problem of trying to find hidden structure in unlabeled data. Because the examples given to the learner are unlabeled, there is no external signal to evaluate a potential solution.
When the task changes, the learning rules (typically effected by adjusting the control parameters w={wi, w2, . . . , wn}) may need to be modified to suit the new task. Hereinafter, the boldface variables and symbols with arrow superscripts denote vector quantities, unless specified otherwise. Complex control applications, such as for example, autonomous robot navigation, robotic object manipulation, and/or other applications may require simultaneous implementation of a broad range of learning tasks. Such tasks may include visual recognition of surroundings, motion control, object (face) recognition, object manipulation, and/or other tasks. In order to handle these tasks simultaneously, existing implementations may rely on a partitioning approach, where individual tasks are implemented using separate controllers, each implementing its own learning rule (e.g., supervised, unsupervised, reinforcement).
One conventional implementation of a multi-task learning controller is illustrated in FIG. 1A. The apparatus 120 comprises several blocks 120, 124, 130, each implementing a set of learning rules tailored for the particular task (e.g., motor control, visual recognition, object classification and manipulation, respectively). Some of the blocks (e.g., the signal processing block 130 in FIG. 1A) may further comprise sub-blocks (e.g., the blocks 132, 134) targeted at different learning tasks. Implementation of the apparatus 120 may have several shortcomings stemming from each block having a task specific implementation of learning rules. By way of example, a recognition task may be implemented using supervised learning while object manipulator tasks may comprise reinforcement learning. Furthermore, a single task may require use of more than one rule (e.g., signal processing task for block 130 in FIG. 1A) thereby necessitating use of two separate sub-blocks (e.g., blocks 132, 134) each implementing different learning rule (e.g., unsupervised learning and supervised learning, respectively).
Artificial neural networks may be used to solve some of the described problems. An artificial neural network (ANN) may include a mathematical and/or computational model inspired by the structure and/or functional aspects of biological neural networks. A neural network comprises a group of artificial neurons (units) that are interconnected by synaptic connections. Typically, an ANN is an adaptive system that is configured to change its structure (e.g., the connection configuration and/or neuronal states) based on external or internal information that flows through the network during the learning phase.
A spiking neuronal network (SNN) may be a special class of ANN, where neurons communicate by sequences of spikes. SNN may offer improved performance over conventional technologies in areas which include machine vision, pattern detection and pattern recognition, signal filtering, data segmentation, data compression, data mining, system identification and control, optimization and scheduling, and/or complex mapping. Spike generation mechanism may be a discontinuous process (e.g., as illustrated by the input spikes sx(t) 220, 222, 224, 226, 228, and output spikes sy(t) 230, 232, 234 in FIG. 2) and a classical derivative of function F(s(t)) with respect to spike trains sx(t), sy(t) is not defined.
Even when a neural network is used as the computational engine for these learning tasks, individual tasks may be performed by a separate network partition that implements a task-specific set of learning rules (e.g., adaptive control, classification, recognition, prediction rules, and/or other rules). Unused portions of individual partitions (e.g., motor control when the robotic device is stationary) may remain unavailable to other partitions of the network that may require increased processing resources (e.g., when the stationary robot is performing face recognition tasks). Furthermore, when the learning tasks change during system operation, such partitioning may prevent dynamic retargeting (e.g., of the motor control task to visual recognition task) of the network partitions. Such solutions may lead to expensive and/or over-designed networks, in particular when individual portions are designed using the "worst possible case scenario" approach. Similarly, partitions designed using a limited resource pool configured to handle an average task load may be unable to handle infrequently occurring high computational loads that are beyond a performance capability of the particular partition, even when other portions of the networks have spare capacity.
By way of illustration, consider a mobile robot controlled by a neural network, where the task of the robot is to move in an unknown environment and collect certain resources by the way of trial and error. This can be formulated as reinforcement learning tasks, where the network is supposed to maximize the reward signals (e.g., amount of the collected resource). While in general the environment is unknown, there may be possible situations when the human operator can show to the network desired control signal (e.g., for avoiding obstacles) during the ongoing reinforcement learning. This may be formulated as a supervised learning task. Some existing learning rules for the supervised learning may rely on the gradient of the performance function. The gradient for reinforcement learning part may be implemented through the use of the adaptive critic; the gradient for supervised learning may be implemented by taking a difference between the supervisor signal and the actual output of the controller. Introduction of the critic may be unnecessary for solving reinforcement learning tasks, because direct gradient-based reinforcement learning may be used instead. Additional analytic derivation of the learning rules may be needed when the loss function between supervised and actual output signal is redefined.
While different types of learning may be formalized as a minimization of the performance function F, an optimal minimization solution often cannot be found analytically, particularly when relationships between the system's behavior and the performance function are complex. By way of example, nonlinear regression applications generally may not have analytical solutions. Likewise, in motor control applications, it may not be feasible to analytically determine the reward arising from external environment of the robot, as the reward typically may be dependent on the current motor control command and state of the environment.
Moreover, analytic determination of a performance function F derivative may require additional operations (often performed manually) for individual new formulated tasks that are not suitable for dynamic switching and reconfiguration of the tasks described before.
Some of the existing approaches of taking a derivative of a performance function without analytic calculations may include a "brute force" finite difference estimator of the gradient. However, these estimators may be impractical for use with large spiking networks comprising many (typically in excess of hundreds) parameters.
Derivative-free methods, specifically Score Function (SF), also known as Likelihood Ratio (LR) method, exist. In order to determine a direction of the steepest descent, these methods may sample the value of F(x,y) in different points of parameter space according to some probability distribution. Instead of calculating the derivative of the performance function F(x,y), the SR and LR methods utilize a derivative of the sampling probability distribution. This process can be considered as an exploration of the parameter space.
Although some adaptive controller implementations may describe reward-modulated unsupervised learning algorithms, these implementations of unsupervised learning algorithms may be multiplicatively modulated by reinforcement learning signal and, therefore, may require the presence of reinforcement signal for proper operation.
Many presently available implementations of stochastic adaptive apparatuses may be incapable of learning to perform unsupervised tasks while being influenced by additive reinforcement (and vice versa). Many presently available adaptive implementations may be task-specific and implement one particular learning rule (e.g., classifier unsupervised learning), and such devices invariably require retargeting (e.g., reprogramming) in order to implement different learning rules. Furthermore, presently available methodologies may not be capable of implementing generalized learning, where a combination of different learning rules (e.g., reinforcement, supervised and supervised) are used simultaneously for the same application (e.g., platform motion stabilization), thereby enabling, for example, faster learning convergence, better response to sudden changes, and/or improved overall stability, particularly in the presence of noise.
Stochastic Spiking Neuron Models
Where certain elements of these implementations can be partially or fully implemented using known components, only those portions of such known components that are necessary for an understanding of the present disclosure will be described, and detailed descriptions of other portions of such known components will be omitted so as not to obscure the disclosure.
Learning rules used with spiking neuron networks may be typically expressed in terms of original spike trains instead of their secondary features (e.g., the rate or the latency from the last spike). The result is that a spiking neuron operates on spike train space, transforming a vector of spike trains (input spike trains) into single element of that space (output train). Dealing with spike trains directly may be a challenging task. Not every spike train can be transformed to another spike train in a continuous manner. One common approach is to describe the task in terms of optimization of some function and then use gradient approaches in the parameter space of the spiking neuron. However gradient methods on discontinuous spaces such as spike trains space are not well developed. One approach may involve smoothing the spike trains first. Here output spike trains are smoothed with introduction of probabilistic measure on a spike trains space. Describing the spike pattern from a probabilistic point of view may lead to fruitful connections with the huge amount of topics within information theory, machine learning, Bayesian inference, statistical data analysis etc. This approach makes spiking neurons a good candidate to use SF/LR learning methods.
One technique frequently used when constructing learning rules in a spiking network, comprises application of a random exploration process to a spike generation mechanism of a spiking neuron. This is often implemented by introducing a noisy threshold: probability of a spike generation may depend on the difference between neuron's membrane voltage and a threshold value. The usage of probabilistic spiking neuron models, in order to obtain gradient of the log-likelihood of a spike train with respect to neuron's weights, may comprise an extension of Hebbian learning framework to spiking neurons. The use of the log-likelihood gradient of a spike train may be extended to supervised learning. In some approaches, information theory framework may be applied to spiking neurons, as for example, when deriving optimal learning rules for unsupervised learning tasks via informational entropy minimization.
An application of the OLPOMDM algorithm to the solution of the reinforcement learning problems with simplified spiking neurons has been done. Extending of this algorithm to more plausible neuron model has been done. However no generalizations of the OLPOMDM algorithm have been done in order to use it unsupervised and supervised learning in spiking neurons. An application of reinforcement learning ideas to supervised learning has been described, however only heuristic algorithms without convergence guarantees have been used.
For a neuron, the probability of an output spike train, y, to have spikes at times t_f with no spikes at the other times on a time interval [0, T], given the input spikes, x, may be given by the conditional probability density function p(y|x) as:
                    p        (                              y                                                    x              )                                =                                    Π                              t                f                                                                λ                                            (                                  t                  f                                )                                                                ⅇ                                                -                                      f                    0                    T                                                                                λ                                                        (                    τ                    )                                                                                ⅆ                  τ                                                                                (                  Eqn          .                                                    1                )            where λ(t) represents an instantaneous probability density ("hazard") of firing.
The instantaneous probability density of the neuron can depend on neuron's state q(t): λ(t)≡λ(q(t)). For example, it can be defined according to its membrane voltage u(t) for continuous time chosen as an exponential stochastic threshold:λ(t)=λoeκ(u(t)-θ)  (Eqn. 2)where u(t) is the membrane voltage of the neuron, θ is the voltage threshold for generating a spike, x is the probabilistic parameter, and λ0 is the basic (spontaneous) firing rate of the neuron.
Some approaches utilize sigmoidal stochastic threshold, expressed as:
                              λ                                (            t            )                          =                              λ            0                                1            -                          ⅇ                              -                                  κ                                                        (                                                                  u                                                                          (                          t                          )                                                                    -                      θ                                        )                                                                                (                  Eqn          .                                                    3                )            or an exponential-linear stochastic threshold:λ(t)=λ0 ln(1+eκ(u(t)-θ))  (Eqn. 4)where λ0, κ, θ are parameters with a similar meaning to the parameters in the exponential threshold model Eqn. 2.
Models of the stochastic threshold exist comprising refractory mechanisms that modulate the instantaneous probability of firing after the last output spike λ(t)={circumflex over (λ)}(t)R(t,tlastout), where {circumflex over (λ)}(t) is the original stochastic threshold function (such as exponential or other), and R(tlastout−t) is the dynamic refractory coefficient that depends on the time since the last output spike tlastout.
For discrete time steps, an approximation for the probability Λ(u(t))ε(0,1] of firing in the current time step may be given by:Λ(u(t))=1−e−λ(u(t))Δt  (Eqn. 5)where Δt is time step length.
In one dimensional deterministic spiking models, such as Integrate-and-Fire (IF), Quadratic Integrate-and-Fire (QIF) and others, membrane voltage u(t) is the only one state variable (q(t)≡u(t)) that is "responsible" for spike generation through deterministic threshold mechanism. There also exist plenty of more complex multidimensional spiking models. For example, a simple spiking model may comprise two state variables where only one of them is compared with a threshold value. However, even detailed neuron models may be parameterized using a single variable (e.g., an equivalent of "membrane voltage" of biological neuron) and use it with a suitable threshold in order to determine the presence of spike. Such models are often extended to describe stochastic neurons by replacing deterministic threshold with a stochastic threshold.
Generalized dynamics equations for spiking neurons models are often expressed as a superposition of input, interaction between the input current and the neuronal state variables, and neuron reset after the spike as follows:
                                          ⅆ                          q              →                                            ⅆ            t                          =                              V                                      (                              q                →                            )                                +                                                    ∑                                  t                  out                                                                                R                                                  (                                      q                    →                                    )                                                                          δ                                                  (                                      t                    -                                          t                      out                                                        )                                                              +                                    G                                            (                                  q                  →                                )                                                                I              ext                                                          (                  Eqn          .                                                    6                )            where:  is a vector of internal state variables (e.g., comprising membrane voltage); Iext is external input to the neuron; F—is the function that defines evolution of the state variables; G describes the interaction between the input current and the state variables (for example, to model synaptic depletion); and R describes resetting the state variables after the output spikes at tout.
For example, for IF model the state vector and the state model may be expressed as:{right arrow over (q)}≡u(t);V({right arrow over (q)})=−Cu;R({right arrow over (q)})=ures−u;G({right arrow over (q)})=1,  (Eqn. 7)where C is a membrane constant, and ures is the value to which voltage is set after output spike (reset value). Accordingly, Eqn. 6 becomes:
                                          ⅆ            u                                ⅆ            t                          =                              -            Cu                    +                                    ∑                              t                out                                                                                (                                                      u                    refr                                    -                  u                                )                                                          δ                                                  (                                      t                    -                                          t                      out                                                        )                                                              +                      I            ext                                              (                  Eqn          .                                                    8                )
For some simple neuron models, Eqn. 6 may be expressed as:
                                                        ⅆ              v                                      ⅆ              t                                =                                    0.04                                            v                2                                      +                          5                            v                        +            140            -            u            +                                          ∑                                  t                  out                                                                                (                                      c                    -                    v                                    )                                                                  δ                                                        (                                          t                      -                                              t                        out                                                              )                                                                        +                          I              ext                                                                                ⅆ              u                                      ⅆ              t                                =                                    a                                            (                                  bv                  -                  u                                )                                      +                          d                                                              ∑                                      t                    out                                                                                δ                                                        (                                          t                      -                                              t                        out                                                              )                                                                                where                            (                  Eqn          .                                                    9                )                                                                                q                →                            =                              (                                                                                v                                                                          (                          t                          )                                                                                u                                                                          (                          t                          )                                                                                )                                      ;                                          V                                                  (                                      q                    →                                    )                                            =                              (                                                                                0.04                                                                                v                              2                                                                                (                              t                              )                                                                                -                                                  5                                                                                v                                                                                (                              t                              )                                                                                +                        140                        -                                                  u                                                                                (                            t                            )                                                                                a                                                                          (                                                                                bv                                                                                (                                t                                )                                                                                -                                                          u                                                                                (                                t                                )                                                                                )                                                                                )                                      ;                                                                                R                                                        (                                          q                      →                                        )                                                  =                                  (                                                                                c                          -                                                      v                                                                                (                              t                              )                                                                                d                                                                              )                                            ;                                                G                                                        (                                          q                      →                                        )                                                  =                                  (                                                                                1                                                                                0                                                                              )                                                      ,                                              (                  Eqn          .                                                    10                )            and a, b, c, d are parameters of the model.
Many presently available implementations of stochastic adaptive apparatuses may be incapable of learning to perform unsupervised tasks while being influenced by additive reinforcement (and vice versa). Many presently available adaptive implementations may be task-specific and implement one particular learning rule (e.g., classifier unsupervised learning), and such devices invariably require retargeting (e.g., reprogrammed) in order to implement different learning rules.
Accordingly, there is a salient need for machine learning apparatus and methods to implement generalized stochastic learning in spiking networks that is configured to handle simultaneously any learning rule combination (e.g., reinforcement, supervised, unsupervised, online, batch) and is capable of, inter alia, dynamic reconfiguration using the same set of network resources.

Systems and apparatus for implementing task-specific learning using spiking neurons


A memory cooling fan tray is composed of a bracket and a plurality of fans. The bracket is formed respectively with a plurality of abutting members, insertion members, and pivoting members. An interior of the bracket is formed with notch members, with a quantity corresponding to the number of fans. After the fans are loosely pivoted at the pivoting members, the fans can rotate freely on the bracket. Upon using, the bracket is inserted into a memory socket, and the fans are electrically connected with a power supply. Blow angles of the fans are adjusted by turning over the fans to change wind directions, so as to actively dissipate heat from the memory.

a) Field of the Invention
The present invention relates to a cooling fan tray used for a purpose of cooling a memory, and more particularly to a memory cooling fan tray which is assembled into a memory socket and uses a feature that fans can be turned over with respect to a bracket for adjustment, to change blow angles.
b) Description of the Prior Art
As a clock speed of a computer is getting quicker and quicker, in addition to a central processing unit, other internal parts, such as memories, display cards, and hard disks, are speeded up correspondingly. As a result, heat generated will be higher and higher. However, there are a lot of places inside a computer case where a cooling flow is unable to reach, which are called hot spots or the locations where the heat is accumulated; especially for a narrow space between the memories, the heat cannot be dissipated successfully, and hence there will be an unstable phenomenon under a long term of usage.
Referring to FIG. 1, it shows a schematic view of a conventional cooling shield structure, wherein a plurality of clamp units 10 are used to attach two cooling shields 20 onto two surfaces of a memory 30, respectively. As a primary heat source of the memory 30 is chips 301 on its surface, the cooling shields 20 are made by a material which is easy to conduct heat, and heat generated from the chips 301 of the memory 30 will be conducted to the cooling shields 20 that are provided with larger areas, thereby dissipating the heat released from the memory 30 by using a merit of large heat dissipation area. However, this passive cooling method is not provided with a good effect. As a space between the memories 30 is very narrow, even that the heat is conducted to the surfaces of the cooling shields 20, the hot spots can be still formed due to that the cooling flow does not pass through these surfaces; therefore, an improvement is needed.


Electronic device configuration management systems and methods are disclosed. Configuration information for configuring at least one component of an electronic device is stored in a memory. A determination is made as to whether further configuration information capable of configuring the at least one component is available at the electronic device. Based on the determination, one of the configuration information and the further configuration information is loaded to configure the at least one component. The determination may be made, for example, by accessing compatibility information which is associated with the configuration information. Data structures supporting configuration management functions are also disclosed.

Electronic devices such as communication devices often incorporate hardware, software, and firmware which cooperate to support device functions. Common hardware components include processors such as Central Processing Units (CPUs), Field Programmable Gate Arrays (FPGAs), Programmable Logic Devices (PLDs), and memory devices, for example. Firmware generally refers to low-level, executable code which controls basic functions of hardware, and may be stored in various types of memory device, including Erasable Programmable Read Only Memory (EPROM), Electrically Erasable PROM (EEPROM), Random Access Memory (RAM) for instance, or effectively embedded into the hardware devices it controls, as in the case of FPGAs and PLDs. Higher-level functions are normally supported in software. Software is normally stored in non-volatile memory, and loaded into volatile memory, illustratively RAM, for execution. Operating system code and software applications represent illustrative examples of software.
A hardware change may be necessary for an electronic device due to a specification change for a particular component, cost reduction reworking of the device, component obsolescence, etc. Hardware changes can present an operations and maintenance problem when a change also necessitates a software or firmware change. This situation may be particularly problematic where an electronic device is an electronic circuit card in communication equipment or part of some other widely deployed electronic system. An enterprise which operates many systems in which particular circuit cards are used and kept as spares may wish to standardize its systems to a given specific version of hardware, software, and firmware. For example, telecommunications service providers typically have this requirement, as do other organizations which require reliable communication or computing networks, including banks, utilities, hospitals, etc.
U.S. patent applications Ser. No. 10/252,703, entitled "SYSTEM AND METHOD FOR MANAGING CONFIGURABLE ELEMENTS OF DEVICES IN A NETWORK ELEMENT AND A NETWORK", filed on Sep. 24, 2002, and published on Jul. 24, 2003 with Publication No. 2003/0140134, and Ser. No. 10/392,867, entitled "SYSTEM AND METHOD FOR TRACKING ENGINEERING CHANGES RELATING TO A CIRCUIT CARD", filed on Mar. 21, 2003, and published on Sep. 23, 2004 with Publication No. 2004/0186690, describe systems and methods for tracking the compatibility of various versions of hardware, software, and firmware associated with an electronic device or a system of electronic devices.
According to the compatibility tracking mechanisms described in the above applications, software and firmware which are compatible with particular hardware are identified and loaded into an electronic device. In the event that compatible software and firmware are not available on the device, new software and firmware may be downloaded from a remote location. Thus, hardware changes which are not fully compatible with previous versions of software and firmware may result in new software and firmware loads.
One disadvantage of distributing separate software and firmware upgrade files for new hardware is that customers must then separately apply patches or new software and firmware, which increases the number of aspects of hardware upgrades which are managed by a customer. Separate software and firmware upgrades also complicate efforts to standardize software for use in all electronic devices operated by an enterprise. Releasing a new application load to customers who have standardized on a previous release, for instance, would involve the customer re-deploying a new load standard. This additional level of upgrade complexity may tend to make customers reluctant to upgrade hardware.
In addition, manufacturers typically cannot ship hardware until they ensure that it works with software. If a new application load is required for new hardware, then this dependence on software may create operations slow-downs until the new application load is qualified. For example, if a new application load is required for a cost reduction hardware change, then the hardware change could not normally be made until the majority of the customer base has moved to a minimum software version that supports the new hardware. This often takes several years after the first software load which supports the cost reduced hardware has been made available to customers.
There are also cases in which there would be significant cost associated with a customer moving to a new application load standard. Customers must often validate a new load before allowing it to be used on in-service equipment. Validation time can range widely, from no validation at all to several months or even a year of test coverage. This may make some customers very reluctant to take new loads without an associated business case, such as where a new load provides no new functionality and thus no new revenue potential.
According to other approaches, complex product numbering schemes are used to ensure that customers order a specific hardware product and matching software/firmware. Clearly, this would be complex to establish, deploy, and maintain. For example, where a cost reduction plan on a product A results in a new version product A2 which requires slightly different firmware, customers, including former purchasers of product A, would need to explicitly order product A2 and corresponding software/firmware A2.
Thus, there remains a need for improved techniques for managing electronic devices and their configuration, through software and/or firmware, for example.


A damping material is made of a porous member having an absolute characteristic impedance value of not less than 800 kg/m2xc2x7S in the frequency range of from 1.0 to 3.0 kHz. A damping method has steps of providing a damping material in the interior or on the periphery of a vibration-generating apparatus, characterized in that as the damping material there is used a compressible porous member having an air permeability of from 1xc3x97{fraction (1/10)}10 to 2xc3x97{fraction (1/10)}2 cc/cm2/sec based on an atmospheric pressure difference of 2.039xc3x97{fraction (1/10)}4 mMH2O or a porous member having an absolute impedance value of not less than 800 kg/m2xc2x7S in a frequency range of from 1 to 3 kHz or one obtained by providing a film layer thereon. A disc drive has a motor for rotating a disc as a data recording medium and a damping material provided in the interior and/or on the periphery of a housing having at least a space in which the disc can be mounted.

1. Field of the Invention
The present invention relates to a damping material excellent in damping properties which can be used as a sound insulation material or damping material for driver in data recording electronic apparatus.
The present invention also relates to a damping method which can minimize vibration developed by the rotational driving of a disc to exert a high sound-insulating or damping effect and thus is suitable for the formation of drive for data recording disc and a disc drive comprising a damping material.
The present application is based on Japanese Patent Applications No. Hei. 10-253258, 10-267466 and 10-267467 which are incorporated herein by reference.
2. Description of the Related Art
Damping materials which absorb or reflect vibration to perform sound insulation or damping have been used for various purposes such as sound insulation, sound absorption, damping, composite thereof, etc.
HDD (hard disc drive), DVDD (digital video disc drive), CDD (compact disc drive), MOD (MO drive), FDD (floppy disc drive), etc. in personal computers comprise a damping material provided in various places, e.g., between the drive main body and the substrate to prevent the generation of noise such as skirr during the rotational driving of a disc as a magnetic or optical data recording medium or the propagation of the motor vibration.
As the foregoing damping material there has heretofore been known a foamed product made of a polyurethane foam or the like. However, if this foamed product is used as a sound insulation material, it is disadvantageous in that there occurs much sound leakage, exerting a reduced sound insulating effect. Therefore, a foamed product having a specified static spring constant, a damping material obtained by forming a finely roughened polymer film on the inner wall of cells in a foamed product, a foamed product having a film applied to the external surface thereof, and a film laminated with a melt blow layer of resin have been proposed (Japanese Patent Publications Sho. 56-157347, Sho. 59-102294, Hei. 4-40381, Hei. 4-345834 and Hei. 7-261768).
However, all the conventional damping materials are disadvantageous in that they exert a poor damping effect and, if used as a sound insulation material, exert an insufficient sound insulating effect or sound deafening effect, making it impossible to prevent the generation of noise. The damping material having a finely roughened polymer film formed thereon, etc. is disadvantageous in that it requires a complicated production process and is produced at a poor production efficiency.
Further, all the conventional disc drives are disadvantageous in that the damping material incorporated therein exerts a poor damping effect and thus exerts a poor effect of deafening sound by sound insulation, sound absorption or damping or a poor effect of inhibiting the propagation of vibration, causing much noise leakage or read/write error.
It is an object of the present invention to develop a damping material excellent in damping properties which can exert a high effect of insulating from sound or damping, can be easily used in a narrow space, can be produced at a good efficiency and can be used for various purposes such as sound insulation and damping.
It is another object of the present invention to provide a damping method which can exert an excellent damping effect to perform high sound insulation or damping and can be easily used in a narrow space or the like and hence provide a disc drive which generates no noise leakage or read/write error.
It is still another object of the present invention to provide a damping material made of a porous member having an absolute characteristic impedance value of not less than 800 kg/m2xc2x7S in the frequency range of from 1.0 to 3.0 kHz.
The damping material according to the present invention can be produced at a high efficiency. The porous member which exhibits the above defined impedance characteristics can exert an excellent effect of minimizing vibrations such as sound incident thereupon. Accordingly, a damping material can be obtained which exerts an excellent sound deafening effect or damping effect to perform high noise prevention or damping and thus can be used for various purposes such as sound insulation, sound absorption, damping and composite thereof. A compressible porous member, if used as a damping material, can be easily loaded in a narrow space or the like, making it possible to prevent the increase of the entire size of the apparatus due to the increase of the thickness of the damping material.
In the foregoing description, if the damping material exhibits a damping factor a satisfying the relationships xcex1xe2x89xa70.01 f neper/m, supposing that the frequency is f, it can exert a drastically enhanced effect of deafening sound or damping to perform further noise prevention or damping. Further, a porous member which exhibits a repulsion stress of from 10 to 200gf/cm2 at 50% compression, if used as a damping material, can be more easily loaded in a narrow space or the like without deforming the adjacent members and can be easily produced.
The present invention also provides a damping method which comprises providing a damping material in the interior or on the periphery of a vibration-generating apparatus, characterized in that as said damping material there is used a compressible porous member having an air permeability of from 1xc3x97{fraction (1/10)}10to 2xc3x97{fraction (1/10)}2cc/cm2/sec based on an atmospheric pressure difference of 2.039xc3x97{fraction (1/10)}4 mmH2O or a porous member having an absolute impedance value of not less than 800 kg/m2xc2x7S in a frequency range of from 1 to 3 kHz.
The present invention further provides a disc drive comprising a motor for rotating a disc as a data recording medium and a damping material provided in the interior and/or on the periphery of a housing having at least a space in which said disc can be mounted, characterized in that said damping material is made of a compressible porous member having an air permeability of from 1xc3x97{fraction (1/10)}10 to 2xc3x97{fraction (1/10)}2 cc/cm2/sec based on an atmospheric pressure difference of 2.039xc3x97{fraction (1/10)}4 mmH2O or a porous member having an absolute impedance value of not less than 800 kg/m2xc2x7S in a frequency range of from 1 to 3 kHz.
In accordance with the present invention, the porous member constituting the damping material exhibits excellent damping properties based on the foregoing air permeability and impedance characteristics to exert a high sound deafening or damping effect developed by sound insulation, sound absorption and damping, making it possible to perform excellent noise prevention or damping for vibration-generating apparatus such as disc drive. Further, the damping material made of a porous member can be produced at a high efficiency and can be easily mounted in a narrow space or the like, making it possible to prevent the increase of the entire size of the apparatus due to the increase of the thickness of the damping material.
In the foregoing description, if the damping material is made of a porous member having a sound absorbing coefficient of not less than 20% at a frequency of 3.15 kHz or a damping factor of not less than 0.01 f neper/m where f is frequency at a frequency of 3.15 kHz, the resulting sound deafening effect or damping effect is drastically enhanced, making it possible to perform better noise prevention or damping. Further, the damping material, if made of a porous member having a repulsion stress of from 10 to 200 gf/cm2 at 50% compression, can be more easily mounted in a narrow space without deforming the adjacent members. Such a damping material can also be easily produced.
Still further, the present invention provides a damping method which comprises providing a damping material in the interior or on the periphery of a vibration-generating apparatus, characterized in that as said damping material there is used one obtained by forming a film layer on a compressible porous member having an air permeability of from 1xc3x97{fraction (1/10)}10 to 2xc3x97{fraction (1/10)}2cc/cm2/sec based on an atmospheric pressure difference of 2.039xc3x97{fraction (1/10)}4 mmH2O or one obtained by forming a film layer on a porous member having an absolute impedance value of not less than 800 kg/m2xc2x7S in a frequency range of from 1 to 3 kHz.
The present invention also provides a disc drive comprising a motor for rotating a disc as a data recording medium and a damping material provided in the interior and/or on the periphery of a housing having at least a space in which said disc can be mounted, characterized in that said damping material is made of a material obtained by forming a film layer on a compressible porous member having an air permeability of from 1xc3x97{fraction (1/10)}10 to 2xc3x97{fraction (1/10)}2 cc/cm2/sec based on an atmospheric pressure difference of 2.039xc3x97{fraction (1/10)}4 mmH2O or a material obtained by forming a film layer on a porous member having an absolute impedance value of not less than 800 kg/m2xc2x7S in a frequency range of from 1 to 3 kHz.
In accordance with the present invention, the damping material is formed by a porous member showing the foregoing air permeability and impedance characteristics to exert an excellent damping effect. Further, the damping material comprises a film layer formed thereon to exert an excellent effect of insulating from sound or preventing the propagation of vibration. Thus, a high sound deafening or damping effect developed by sound insulation, sound absorption and damping can be exerted, making it possible to perform excellent noise prevention or damping for vibration-generating apparatus such as disc drive.
Further, the damping material made of porous member and film layer can be produced at a high efficiency. The damping material reinforced by the film layer can be more fairly handled and thus can be fairly mounted in the apparatus, making it possible to inhibit the scattering of properties such as sound insulation and damping. Thus, the stability and reliability in prevention of noise, vibration, etc. can be enhanced. Further, the damping material can be easily mounted in a narrow space, making it possible to inhibit the increase of the entire size of the apparatus due to the increase of the thickness of the damping material.
In the foregoing description, if the damping material is made of a porous member having a sound absorbing coefficient of not less than 20% at a frequency of 3.15 kHz and a damping factor xcex1 satisfying the relationship: xcex1xe2x89xa70.01 f neper/m, supposing that the frequency is f, it can exert a drastically enhanced effect of deafening from sound or damping to perform further noise prevention or damping. Further, a porous member which exhibits a repulsion stress of from 10 to 200 gf/cm2 at 50% compression, if used as a damping material, can be more easily loaded in a narrow space or the like without deforming the adjacent members and can be easily produced.
Features and advantages of the invention will become understood from the following detailed description of the preferred embodiments described in conjunction with the attached drawings.

Damping material, damping method and disc drive


A stiffened balloon apparatus with increased flexibility is provided for use in the human body. The stiffened balloon apparatus incorporates one or more stiffeners having at least one thinned area to facilitate bending or flexing of the stiffener as the apparatus is navigated through a passage. The thinned area of a stiffening member facilitates navigation of the stiffened balloon apparatus through a curved passage.

Inflatable balloons are employed to dilate stenotic arteries in angioplasty, i.e., percutaneous transluminal coronary angioplasty (PTCA), to dilate stenotic cardiac valves in valvuloplasty, and to deliver and reconfigure stents and stent-grafts. To prevent late lumen loss and restenosis, a stent is carried on a balloon, positioned and expanded to remain in a dilated vessel. Unfortunately, currently available balloon systems for angioplasty and for delivery and expansion of stents often fail to properly deploy the stent to produce a uniform diameter and cross-sectional area along the length of the stent. This results from the very nature of such a cylindrical balloon which is made of a thin, flexible membrane and hence can expand radially to different diameters along its longitudinal dimension. If an obstructive lesion in a blood vessel is of a firmer and less compliant tissue than the normal vascular wall, e.g., fibrous or calcified matter, such tissue presents a much greater resistance than the normal vascular wall to dilatation as the balloon expands. As a balloon is expanded, such stenoses, narrowings, and obstructions impinge upon the expanding balloon to cause an area of relative narrowing or distortion, a so-called "waist". Correspondingly, a stent delivered on such a balloon will suffer from a similar distortion or "waist configuration" as it is conformably expanded with the expanding delivery balloon.
If the stent adopts a "waist configuration", it is generally indicative of inadequate dilatation of the stenotic lesion within the blood vessel. The conventional approach to attempt to remedy this inadequacy has been to increase pressure within the balloon to expand the narrowed area. At times, a separate, higher pressure balloon is utilized. To produce such higher pressure balloons, flexible balloon membranes, which could rupture under increasing internal pressure, were replaced by more rigid balloon materials that permitted much higher internal pressures. However, the more rigid material still has an elastic limit. Balloons made of such material and excessively inflated will be permanently deformed, and may eventually burst. Such deformed balloons are much more difficult to remove from the patient. Moreover, increasing the pressure in the balloon increases the potential for rupture and serious harm to the patient.
Even the use of higher pressures permitted by more rigid balloons are insufficient to dilate some arterial stenoses, particularly if they have an annular configuration. With the stent not completely open and the lumen not fully dilated, the final therapeutic result is less than optimum. Some residual stenoses and a non-uniform cross-sectional area along the length of the stent will result.
Another problem frequently encountered during balloon dilation of stents is the occurrence of flaring of the stent at its ends. Stents are generally manufactured as an independent cylindrical structure or integrated in a sleeve that is slipped onto the balloon and adhered. Conventionally, the balloons are at least slightly longer than the stents that they carry.
As the balloon is inflated and it expands the stent, it typically meets less resistance at the ends of the stent and outside the confines of the stent than it does within the stent. Hence, at full inflation the balloon has a tendency to expand to a slightly larger diameter beyond the ends of the cylindrical stent than at the middle of the stent. The resulting different diameters of expansion are transferred to the stent causing a "trumpet-like" outward flaring of the stent at its ends, which is undesirable.
Additionally, there are several problems with the conventional methodology for delivering a stent to an occlusive site with a conventional balloon catheter. In trying to force the stent inside a tight occlusion, calcified matter or other irregularity at the occlusion often provides resistance against the leading edge of the balloon catheter and may resist entry and positioning of the stent. As the operator tries to advance or withdraw the catheter, the calcified matter or other irregularity may catch hold of the stent and capture it in place while the catheter is moved, causing the stent to separate from the balloon. If the stent is displaced with respect to the balloon, slips partially off the balloon, or separates from the balloon entirely, then the stent will not deploy properly. If the undeployed stent separates from the balloon entirely, retrieving the undeployed stent becomes a very serious problem. Similarly, a stent that is only partially deployed or is incorrectly positioned presents a very significant risk to the patient.
Where an occlusive site is only partially accessible by means of a conventional balloon catheter, i.e., only one end of an occlusion has an inner diameter that is of sufficient size to receive a balloon catheter, expansion of the balloon often causes the entire device to be squeezed and slip out of the occlusive site entirely. Thus, attempts to open such partially accessible occlusive sites often fail. To keep the prior art device within the occlusive site a great deal of force may need to be applied by the operator to prevent the device from slipping out. Such force causes additional stress at the occlusive site and in surrounding structures which present a further risk of rupturing the target site or causing damage to the surrounding areas. This same behavior is also observed in situations where an occlusion is irregular in diameter and the expanded balloon simply slips out of the occlusive site upon reaching a particular state of expansion.
The same difficulties are encountered in attempting to position and deploy a stent-graft with a conventional balloon catheter. Incomplete stent-graft deployment can result in troublesome endoleaks caused by inadequate or otherwise ineffective sealing of the stent-graft at the ends with the interior of the vessel. Such endoleaks allow a channel of blood flow to develop that bypasses the stent-graft, greatly reducing its effectiveness and potentially causing the stent-graft to migrate. Where stent-grafts are deployed to exclude aneurysms, such as in the endovascular repair of an abdominal aortic aneurysm, endoleaks are a very significant problem in that they may allow flow to an aneurysm that could cause the aneurysm to rupture.
U.S. Pat. No. 4,796,629, by one of the present inventors, describes a stiffened dilation balloon which addresses some of these problems by providing an expandable balloon which exerts greater expansion force on localized regions within the lumen. It has been found that the uniform expansion provided by the balloon catheter device described in U.S. Pat. No. 4,796,629 achieves superior results in dilating occluded vessels. As such a stiffened dilation balloon is expanded within an occlusion, the longitudinal stiffener, acting as a rigid beam, transmits expansion force applied to the entire length of the stiffener by the balloon to the localized points of resistance in the vessel. Thus, as compared to a conventional balloon, the force of dilation applied locally is considerably increased and dilatation of highly resistant lesions is greatly facilitated. Such a stiffened dilation balloon is capable of achieving the same degree of dilatation as a standard balloon delivery system but at lower pressures. The stiffeners significantly increase the rigidity of the balloon, reducing variations in the cross-sectional area of the balloon along its length and reducing the occurrence of annular regions with a narrowed waist.
Additionally, it has also been found that an inherent limitation of the balloon catheter device described in U.S. Pat. No. 4,796,629 is its limited maneuverability for deployment in the vascular system. The stiffeners of such a device are fairly rigid, have a fixed length in excess of the turning radius needed to navigate certain pathways and have a fixed, although not necessarily uniform, cross-section. As a result, it can be particularly difficult to navigate the device of U.S. Pat. No. 4,796,629 through the vascular system to reach certain occlusions in smaller vessels without utilizing non-standard entry locations or invasive manual procedures for straightening tortuous vascular pathways.

Stiffened balloon apparatus with increased flexibility