A circuit for driving an organic light emitting element by alternating current in an active matrix organic light emitting display is provided. A circuit of a pixel provided with a switching TFT and a current controlling TFT further is provided with an element that has a rectifying characteristic. The switching TFT charges a capacitor in accordance with a data signal and the current controlling TFT controls light emission of an organic light emitting element in accordance with voltage supplied from the capacitor. Reverse bias is readily applied to the organic light emitting element by applying voltage to the element that has a rectifying characteristic in the forward direction from an alternating current source.

1. Field of the Invention
The present invention relates to a display device which has an organic light emitting element and to a method of driving the display device. Specifically, the present invention relates to a display device in which an organic light emitting element is driven with alternating current and a driving method thereof.
2. Description of the Related Art
In recent years, a technique of forming a transistor, for example, a TFT (thin film transistor) on a substrate has been advanced greatly to promote development of active matrix display devices. Active matrix display devices are free from the problem of cross talk in passive matrix display devices and therefore are capable of displaying images with higher definition and contrast compared to passive matrix display devices.
TFTs using polysilicon for their active layers have higher field effect mobility than conventional TFTs that use amorphous silicon and therefore can operate at high speed. This makes it possible to perform control the luminance of pixels, which has conventionally been done by an external driving circuit to the substrate, by a driving circuit formed on the same substrate on which the pixels are formed. Thus formed active matrix display devices can have various circuits and elements on the same substrate, which helps to reduce the display devices in size.
A display device using organic light emitting elements (hereinafter referred to as organic light emitting displays) has also been developed actively in recent years. An organic light emitting elements is self-luminous and does not need a light source such as back light, unlike liquid crystal display devices. Therefore, organic light emitting elements is deemed as promising means for reducing weight and thickness of display devices, and are expected to be used in cellular phones, personal portable information terminals (personal digital assistant: PDA), and the like.
An organic light emitting element has a diode structure with an organic compound layer sandwiched between two electrodes and emits light by re-combining electrons injected from one of the electrodes with holes injected from the other electrode in an organic compound layer. The organic light emitting element provides electro-luminescence (EL), for example, fluorescence or phosphorescence. Because of the diode structure, the organic light emitting elements is also called organic light emitting diodes (OLEDs).
An organic light emitting element is often composed of an anode, a hole transporting layer, a light emitting layer, an electron transporting layer, and a cathode. This structure is so high in light emission efficiency that almost all organic light emitting elements that are under development at present employ this structure. One or both of hole injection layer and electron injection layer are omitted in some cases. However, a light emitting layer is an indispensable component to an organic light emitting element since an organic light emitting element emits light through recombination of carriers when current flows into the light emitting layer.
An organic compound layer is a collective name for carrier (electrons and holes) transporting layers, a light emitting layer that is formed of a material with high quantum yield, and other layers. The light emitting layer, hole injecting layer, and electron injecting layer mentioned above are included in the organic compound layer.
An organic light emitting element has a high rectifying characteristic and emits light through recombination of carriers when the electric potential of its anode exceeds the electric potential of the cathode to cause current to flow in the organic compound layer. On the other hand, when the electric potential of the anode is lower than the electric potential of the cathode, current does not flow in the organic compound layer and no light is emitted. In the diode structure as an organic light emitting element, voltage applied in a direction, in which current readily flows is called forward bias whereas voltage applied in a direction in which current finds it difficult to flow, is called reverse bias.
FIG. 19 shows an equivalent circuit of a pixel portion in a conventional active matrix organic light emitting display.
Gate signal lines (G1 to Gn) are connected to gate electrodes of switching TFTs of pixels. Each switching TFT is denoted by 901 and each pixel is denoted by 900. Each switching TFT has a source and a drain, one of which is connected to one of source signal lines (S1 to Sn) for inputting data signals and the other of which is connected to a gate electrode of a current controlling TFT 902 and to one of electrodes of a capacitor 903. Each pixel has one current controlling TFT 902 and one capacitor 903. The other electrode, namely, one of electrodes of a capacitor that is not connected to a switching TFT is connected to one of power supply lines (V1 to Vm).
Each current controlling TFT has a source and a drain, one of which is connected to one of the power supply lines and the other of which is connected to a pixel electrode of an organic light emitting element 905. Each pixel has one organic light emitting element 905. An opposite electrode of an organic light emitting element faces the pixel electrode of the organic light emitting element and sets the reference electric potential for the pixel electrode.
For conveniences' sake of explanation, an opposite electrode is connected to an opposite power supply 906. The difference in electric potential between the power supply lines and the opposite power supply is set to a level at which the voltage is large enough to cause an organic light emitting element to emit light.
Each organic light emitting element 905 has an anode and a cathode, one of which serves as a pixel electrode and the other of which serves as an opposite electrode. An anode of an organic light emitting element serves as a pixel electrode and a cathode of the organic light emitting element serves as an opposite electrode when the anode of the organic light emitting element is connected to a source or drain of a current controlling TFT. On the other hand, a cathode of an organic light emitting element serves as a pixel electrode and an anode of the organic light emitting element serves as an opposite electrode when the cathode of the organic light emitting element is connected to a source or drain of a current controlling TFT.
The luminance of light emitted from an organic light emitting element is determined as follows. A selection signal is inputted from the gate signal line to the gate electrode of the switching TFT 901 to turn the switching TFT ON (conductive). Then, a data signal inputted to the source signal line is inputted to the gate electrode of the current controlling TFT 902 through the switching TFT. The electric potential of the gate electrode of the current controlling TFT is held by the capacitor 903. Accordingly, the difference in electric potential between the gate electrode of the current controlling TFT 902 and the power supply line (one of V1 to Vm), namely, the gate voltage of the current controlling TFT is kept constant until a next data signal is inputted to the pixel.
When the current controlling TFT is turned ON, current flows from a semiconductor layer of the current controlling TFT to the organic light emitting element that is connected in series to the semiconductor layer of the current controlling TFT. The intensity of light emitted from the organic light emitting element is determined in accordance with the amount of current that flows into the organic light emitting element. The amount of current flowing into a current controlling TFT is controlled by a data signal inputted to each pixel and therefore the luminance of light emitted from each pixel can be controlled by the electric potential of data signal.
In general, 'driving an organic light emitting element with direct current' means maintaining light emission by keeping the electric potential of an anode higher than the electric potential of a cathode to cause direct current to flow. In this case, the anode is either an opposite electrode or a pixel electrode and the cathode is the other of the two electrodes.
However, when an organic light emitting element is driven with direct current, the luminance of light emitted from the organic light emitting element is lowered with time. Direct current driving causes degradation of luminance with age supposedly because ionic impurities accumulate in the interface of the organic compound layer and molecules constituting the organic compound layer are polarized in a single direction along the electric field to create inside the organic compound layer an electric field reversely oriented with respect to an electric field applied by the pixel electrode or the opposite electrode of the organic light emitting element.
In particular, the luminance of light emitted from an organic light emitting element is markedly lowered with time if the organic light emitting element is driven while the voltage applied between the cathode and anode of the organic light emitting element is kept constant (hereinafter referred to as constant voltage method). In the constant voltage method, since the level of the voltage applied to the cathode and the anode is always constant, the effective voltage applied to the organic compound layer is reduced as the intensity of the electric field created in the organic compound layer increases to lower the luminance of light emitted from the organic light emitting element.
In order to prevent this degradation of luminance, the organic light emitting element has to be driven with alternating current. 'Driving an organic light emitting element with alternating current' means alternately applying voltages with different polarities to the organic light emitting element. In other words, reverse bias is applied in addition to forward bias that is necessary for light emission. Forward bias and reverse bias may not always have the same magnitude or application time. When a minute reverse bias is applied, it still is regarded as alternating current driving.
However, in the conventional circuit described above, connecting an alternating current source to the opposite electrode of the organic light emitting element and to the power supply lines is sometimes not enough to apply a sufficient reverse bias to the organic light emitting element. This will be explained below.
The circuit shown in FIG. 19 is a closed circuit in which the source or drain of the current controlling TFT 902 is connected serially to the organic light emitting element 905 between the opposite power supply 906 and the power supply line (one of V1 to Vm). The operation of this closed circuit in applying voltages to the organic light emitting element with alternating current is described. To simplify the explanation, the current controlling TFT in the description below is a p-channel TFT. The p-channel TFT is turned ON when the electric potential of the gate is lower than the electric potential of the source, namely, the electric potential of the power supply line and the difference thereof exceeds the threshold.
Therefore, in order to apply forward bias to the organic light emitting element, the electric potential of the opposite electrode of the organic light emitting element 905 is set to the Lo level whereas the electric potential of the power supply line is set to the Hi level, and the electric potential of the gate of the current controlling TFT is lower than the electric potential of the power supply line (the source of the current controlling TFT) to exceeding the threshold. The current controlling TFT is turned ON, namely, conductive, and current flows into the organic light emitting element 905 to cause the organic light emitting element to emit light.
When the current flowing into the organic light emitting element is to be stopped without changing the electric potentials of the power supply line and opposite electrode, the electric potential of the gate of the current controlling TFT is set higher than the electric potential of the source thereof to turn the current controlling TFT OFF.
Suppose that now the current controlling TFT is ON and the electric potentials of the power supply line and opposite electrode are inverted to apply reverse bias to the organic light emitting element. That is, the electric potential of the opposite electrode of the organic light emitting element 905 is set to the Hi level whereas the electric potential of the power supply line is set to the Lo level. At this point, the series circuit consisting of the opposite electrode, the organic light emitting element, the current controlling TFT, and the power supply line is equivalent to a source follower circuit. Accordingly, a great reduction in voltage occurs here since the gate electric potential of the current controlling TFT is low, and therefore only insufficient reverse bias is applied to the organic light emitting element.
As has been described, outputting an alternating current waveform between the opposite power supply 906 and the power supply line is sometimes not enough to apply a sufficient reverse bias to the organic light emitting element. The same applies to the case where the current controlling TFT is an n-channel TFT in order that current flows from an anode to a cathode in an organic light emitting element when a pixel electrode of the organic light emitting element serves as the cathode and a opposite electrode thereof serves as the anode.
It is thus difficult to drive an organic light emitting element with alternating current in the conventional circuit structure described above, and the problem of great reduction in luminance of an organic light emitting element with time due to application of direct current voltage is yet to be solved.

Display device and method of driving the same

Semiconductor Energy Laboratory Co., Ltd.


A tensioning system of a mooring line of a floating structure. The mooring line includes separate first and second mooring line sections, with a first end of the second mooring line attached to the floating structure and a first end of the first mooring line section being attached to an anchoring device embedded in a seabed. A tensioner configured to act on the mooring line includes a body with a housing, and an inlet unit for inserting a second end of the first mooring line section into the housing of the body. The body includes an opening for the passage of a second end of the first mooring line section from the inlet unit, through the housing, and along a direction changing element. The tensioning system includes a stabilizing platform fixed to the body. At least a portion of the stabilizing platform laterally projects from the body of the tensioner.

Floating structures, such as drilling vessels or offshore platforms, have to be moored to the seabed in a given fixed area, so as to not be subjected to the displacements that may be caused by sea currents or atmospheric conditions. Anchoring devices of different types which are moored to mooring lines that are attached to the vessels or platforms are used. Initially, when floating structures are moored to the seabed the mooring lines must be tensioned in order to keep the floating structures in place. Over time, the mooring lines loosen and they must be tensioned again. The mooring lines are tensioned with tensioners.
US20160185427A1 describes a tensioner of a mooring line of a floating structure, the mooring line comprising a first mooring line and a second mooring line, with the mooring lines being separate from one another, wherein one of the mooring lines comprises a first end attached to the floating structure, and the other mooring line comprises a first end attached to an anchoring device which is secured to the seabed, the tensioner comprising an elongated body with a base and a longitudinal housing configured for housing a chain segment of the first mooring line, a connection unit attached to the body at one of its ends comprising a connector member configured for attaching a second end of the second mooring line to the body, and an inlet unit attached to the body at the other end and configured for inserting a second end of the first mooring line into the housing of the body, the body comprising an opening in the upper part for the passage of the second end of the first mooring line from the inlet unit, through the housing, and along a direction changing element.

Tensioner of a mooring line of a floating structure


A method and apparatus for continuously extracting liquid in at least two separate streams from a vessel, continuously diluting and/or conditioning a first stream in one or more stages, producing, as a result of the extraction, dilution and/or conditioning, the first stream consisting of a dispersion of particles to be characterized, and diluting and/or conditioning a second stream, the second stream consisting of soluble components; and subjecting the first and second streams to various characterizing measurements.

1. Field of the Invention
The present invention relates to the simultaneous characterization of microscopic particles in suspension and soluble components diluted in a different fluid.
2. General Background of the Invention
Polymerization reactions in heterogeneous phase are widely used in industry, and comprise many tens of billions of dollars per year in production, worldwide. The present invention involves polymers produced in heterogeneous phases such as micelles, miniemulsions, macroemulsions, suspensions, and the latex particles that result. The term "emulsion polymerization reactions" (EPR) includes polymers produced in heterogeneous phases such as micelles, miniemulsions, macroemulsions, suspensions, and the latex particles that result, as well as inverse micelles, inverse miniemulsions, and inverse macroemulsions. The term "particle" used in the context of "particle characterization" includes, but is not limited to, for example, micelles, latex particles, aggregates, emulsions, inverse micelles, inverse emulsions, and miniemulsions.
Strong economic and environmental motivations are fueling a growing trend toward making more use of EPR: EPR reduces the use of dangerous organic solvents (EPR are normally carried out in water, whereas inverse phases are usually carried out in oils), EPR allows better control of thermodynamics (exothermicity), and the emulsion liquids used in EPR have low viscosity and are easy to handle, pump, transport, store, and apply. Furthermore, the latex particles produced by EPR often have desirable end products, for example, paints, coatings, and adhesives.
As in any process where a particular composition of matter is sought through chemical reactions (covalent), including biochemical reactions, as well as physical (non-covalent) interactions of initial substances, entities (e.g. cells), and reagents, it is inherently valuable to be able to monitor the changes that occur in realtime or near realtime.
In general, there are many advantages to being able to monitor such reactions. Monitoring gives a fundamental understanding of the reaction kinetics and mechanisms, and the evolution of polymer properties (such as molecular weight) during synthesis, allowing the development of advanced polymeric materials. Monitoring gives the ability to optimize reaction conditions, including, for example, pressures, temperatures, reagents, monomers, activators, catalysts, process steps and stages, and also yields the ability to provide full control of large scale production of polymers, biopolymers, and other substances. Such control leads to novel and superior products, better quality control, more efficient use of natural and non-renewable resources, energy, and plant and personnel time.
In the case of EPR, the advantages of accurate comprehensive monitoring of the reactions leads to optimized latex particles using particle characterization, whereas monitoring the soluble components in a separate analysis stream can allow quantification of conversion of reagents, such as monomers and comonomers, thus allowing the personnel involved to know at what stage the reaction is, whether the reaction is functioning correctly, when it is time to add new or different reagents, how to change the flow of reagents in continuous or semi-batch reactors, when to perform other actions affecting the reaction, such as changing temperature, and when to stop the reaction. Monitoring the soluble components also allows the evolution of polymeric properties to be followed, for example, average molar masses, intrinsic viscosity, the degree of polymer branching and the degree of polymer grafting. The type of simultaneous monitoring disclosed herein leads to such a better fundamental understanding of the complex processes involved in EPR that new procedures may be developed, and/or redundant or counterproductive steps in old procedures may be identified and/or eliminated.
There has been, and continues to be, much effort expended to monitor EPR, but the focus for particle characterization has usually been on manually withdrawing discrete aliquots and making particle size measurements, usually with dynamic light scattering (DLS). Monomer conversion is separately measured by drying and weighing discrete samples, or by other means, such as Gel Permeation Chromatography (GPC), often also referred to as Size Exclusion Chromatography (SEC). Another growing area for monitoring monomer conversion involves in-situ reactor probes of near infra-red, Raman scattering, ultrasound, and calorimeters. These processes, while providing continuous automatic signals, give only empirical information about changes in the reaction, require empirical or inferential calibration schemes, can contain signals from other effects that obscure the useful portion of the signal (e.g. scattering by emulsions rather than absorption by monomers can dominate spectroscopic signals using electromagnetic probe radiation) and are directly subject to often harsh reactor interiors that leads to rapid fouling, failure of calibration, and instrument malfunction.
The disadvantage of manually withdrawing discrete aliquots and making particle size measurements, often with DLS, is that it is labor intensive, inefficient, slow, potentially dangerous to personnel, and also risks contamination in the reaction vessel. Some progress has been made, nonetheless, in automatic dilution of emulsion reactor contents for particle sizing measurements by DLS and combined low, mid, and high angle light scattering, notably by Malvern Ltd. of the UK.
The disadvantage to monitoring monomer conversion by separately drying and weighing discrete samples, or by other means, is that it is time consuming, labor intensive, and only yields few conversion points, with a very long delay between withdrawal and measurement. This is suitable neither for reactor control nor for fundamental studies of reaction kinetics.
The disadvantage of the in-situ probes is that they are subject to harsh conditions, can easily foul or be damaged, deliver limited information (e.g. only conversion), and are predicated on empirical or inferential models that quickly change as reactor conditions and probe conditions change.
There does not seem to be any precedent in the field for a device or method which simultaneously and automatically measures both colloid and polymer/monomer aspects of EPR.
Incorporated herein by reference are all patents and patent applications naming one or more of the inventors herein as an inventor, and all publications listing one or more of the inventors as an author, including the following: International Publication No. WO01/29534 A1, US Patent Publication No. US 2004/0004717, U.S. Pat. No. 6,653,150, U.S. Pat. No. 6,618,144, and U.S. Pat. No. 6,052,184.
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REED, "Continuous Monitoring of the Effect of Changing Solvent Conditions on Polyelectrolyte Conformations and Interactions", Int. J. of Polymer Characterization and Analysis, 7, 1-19, 2002; A. GIZ, H. GIZ, J. L. BROUSSEAU, A. ALB, and W. F. REED, "Kinetics and Mechanism of Acrylamide Polymerization by Absolute, Online Monitoring of Polymerization Kinetics", Macromolecules, 34, 5, 1180-1191, 2001; A. GIZ, H. GIZ, J. L. BROUSSEAU, A. ALB, W. F. REED, "Online Monitoring of a Stepwise Polymerization Reaction: Polyurethane", J. App. Polym. Sci., 82, 2070-2077, 2001; J. L. GANTER, W. F. REED, "Real-time Monitoring of Enzymatic Hydrolysis of Galactomannans", Biopolymers, 59, 226-242, 2001; B. GRASSL, A. M. ALB, W. F. REED, "Free radical transfer rate determination using online polymerization monitoring", Macromolecular Chemistry and Physics, 202, 2518-2524, 2001; G. A. SORCI, W. F. REED, "Electrostatic and Association Phenomena in Aggregates of Polymers and Micelles", Langmuir, 18, 353-364, 2002; B. GRASSL, W. F. REED, "Online polymerization monitoring in a continuous tank reactor", Macromolecular Chemistry and Physics, 203, 586-597, 2002; F. CHAUVIN, A. M. ALB, D. BERTIN, W. F. REED, "Kinetics and molecular weight evolution during controlled radical polymerization", Macromolecular Chemistry and Physics, 203, 2029-2040, 2002; G. A. SORCI, W. F. REED, "Electrostatically enhanced second and third virial coefficients, viscosity and interparticle correlations for linear polyelectrolytes", Macromolecules, 35, 5218-5227, 2002; A. GIZ, A. Oncul KOC, H. GIZ, A. M. ALB, W. F. REED "Online monitoring of reactivity ratios, composition, sequence length, and molecular weight distributions during free radical copolymerization", Macromolecules, 35, 6557-6571, 2002; W. F. REED, "Monitoring Kinetic Processes in Polymer Solutions with Time Dependent Static Light Scattering (TDSLS)", Ch. 12, pp. 131-151, in Scattering Methods for the Investigation of Polymers, J. Kahovec, Ed., Wiley VCH, 2002; W. F. REED, A. M. ALB, E. MIGNARD, H. GIZ, A. GIZ, F. H. FLORENZANO, R. FARINATO "Automatic Continuous Online Monitoring of Polymerization Reactions (ACOMP)", Polymeric Materials: Science and Engineering, 88, 476-478, 2003; M. F. DRENSKI, W. F. REED, "Simultaneous Multiple Sample Light Scattering (SMSLS)", Polymeric Materials: Science & Engineering, 88, 304-305, 2003; E. MIGNARD, O. GUERRET, D. BERTIN, W. F. REED, "Automatic Continuous Online Monitoring of Polymerization Reactions (ACOMP) of High Viscosity Reactions", Polymeric Materials: Science and Engineering, 88, 314-316, 2003; W. F. REED, "Automatic, Continuous Mixing Techniques for Online Monitoring of Polymer Reactions and for the Determination of Equilibrium Properties", Ch. 20, 589-622, Handbook of Size Exclusion Chromatography and Related Techniques, 2nd Ed., Chi-san Wu, Ed., Marcel Dekker, 2003; H. çATALGIL-GIZ, A. GIZ, A. M. ALB, W. F. REED, "Absolute Online Monitoring of Acrylic acid Polymerization and the Effect of Salt and pH on Reaction Kinetics", J. Applied Polymer Science, 91, 1352-1359, 2004; G. A. SORCI, W. F. REED, "Effect of valence and chemical species of added electrolyte on polyelectrolyte conformations and interactions", Macromolecules, 37, 554-565, 2004; E. MIGNARD, T. LEBLANC, D. BERTIN, O. GUERRET, W. F. REED, "Online monitoring of controlled radical polymerization: Nitroxide mediated gradient copolymerization", Macromolecules, 37, 966-975, 2004; W. F. REED, "Fundamentals of static light scattering and viscometry in SEC and related methods", ACS Ser. 893 Multiple Detection Size-Exclusion Chromatography, A. M. Striegel, Ed., ACS: Washington, D.C., 2004; W. F. REED, "Automatic Continuous Online Monitoring of Polymerization reactions (ACOMP)", Polymer News, 29, 271-279, 2004; M. F. DRENSKI, W. F. REED, "Simultaneous Multiple Sample Light Scattering for Characterization of Polymer Solutions", J. App. Polym. Sci., vol. 92, 2724-2732, 2004; A. M. ALB, E. MIGNARD, M. F. DRENSKI, W. F. REED, "In Situ Time dependent signatures of light scattered from solutions undergoing polymerization reactions", Macromolecules, 37, 2578-2587, 2004; M. F. DRENSKI, E. MIGNARD, A. M. ALB, W. F. REED, "Simultaneous in Situ Monitoring of Parallel Polymerization Reactions using Light Scattering; a New Tool for High Throughput Screening", J. Combinatorial Chemistry, 6, 710-716, 2004; F. H. FLORENZANO, V. FLEMING, P. ENOHNYAKET, W. F. REED, "Coupling of Near Infra-Red spectroscopy to Automatic Continuous Online Monitoring of Polymerization Reactions", European Polymer Journal, 41, 535-545, 2005; R. S. FARINATO, J. CALBICK, G. A. SORCI, F. H. FLORENZANO, W. F. REED, "Online monitoring of the final divergent growth phase in the stepgrowth polymerization of polyamines" Macromolecules, 38, 1148-1158, 2005; E. MIGNARD, J-F LUTZ, T. LEBLANC, K. MATYJASZEWSKI, O. GUERRET, W. F. REED, "Kinetics and Molar Mass Evolution during Atom Transfer Radical Polymerization of n-Butyl Acrylate Using Automatic Continuous Online Monitoring." Macromolecules, 38, 9556-9563, 2005; A. M. ALB, R. FARINATO, J. CALBECK, W. F. REED, "Online monitoring of polymerization reactions in inverse emulsions", Langmuir, 22, 831-840, 2006; A. M. ALB, P. ENOHNYAKET, M. DRENSKI, A. HEAD, A. W. REED, W. F. REED, "Online monitoring of copolymerization using comonomers of similar spectral characteristics", Macromolecules, 39, 5705-5713, 2006; A. M. ALB, P. ENOHNYAKET, R. SHUNMUGAM, G. N. TEW, W. F. REED, "Quantitative contrasts in the copolymerization of acrylate and methacrylate monomers", Macromolecules, 39, 8283-8292, 2006; M. F. DRENSKI, E. MIGNARD, W. F. REED, "Direct Measurement of Chain Transfer during Controlled Radical Polymerization", Macromolecules, 39, 8213-8215, 2006; A. M. ALB, P. ENOHNYAKET, J. F. CRAYMER, T. EREN, E. B. COUGHLIN, W. F. REED, "Online monitoring of Ring Opening Metathesis Polymerization of Cyclooctadiene and a Functionalized Norbornene", Macromolecules, 40, 444-451, 2007; A. M. ALB, A. PARIL, H. çATALGIL-GIZ, A. GIZ, W. F. REED, "Evolution of composition, molar mass, and conductivity during the free radical copolymerization of polyelectrolytes", J. Phys. Chem. B., 111, 8560-8566, 2007; A. PARIL, A. M. ALB, W. F. REED, "Online Monitoring of the Evolution of Polyelectrolyte Characteristics during Postpolymerization Modification Processes", Macromolecules, 40, 4409-4413, 2007;

Methods and devices for simultaneously monitoring colloid particles and soluble components during reactions

The Administrators of the Tulane Educational Fund


The present invention provides a ferromagnetic tunnel magnetoresistive film which is associated with a high output and whose magnetoresistive ratio is less dependent on a bias voltage. In a three-terminal ferromagnetic tunnel magnetoresistive element, a decrease in an output is suppressed by a bias voltage V1 applied to one of the tunnel junctions. By employing half-metallic ferromagnets 11 and 12 in the element, the output can be enhanced and the dependency on the applied bias voltage can be reduced.

1. Field of the Invention
The present invention relates to a ferromagnetic tunnel magnetoresistive element and a magnetic head using the same.
2. Description of Related Prior Art
Conventionally, ferromagnetic tunnel magnetoresistive (TMR) elements have been proposed as one type of magnetoresistive elements. JP-A-10-4227 describes a magnetic head using a TMR element. However, the magnetoresistance of such a conventional TMR element depends greatly on an applied voltage where a TMR ratio becomes lower as a voltage is applied. In order to employ the TMR element in a magnetic head or a magnetic memory, it is necessary to increase the output while decreasing the dependency thereof on the applied voltage. An increase in the output can be achieved by applying a half-metallic ferromagnet whose degree of spin-polarization is higher than that of a magnetic ferromagnet used in the conventional TMR element. An attempt to increase a TMR ratio in a TMR element using a material associated with a high degree of spin-polarization (La0.7Sr0.3MnO3/SrTiO3/La0.7Sr0.3MnO3) is described in Europhysics Letters, 39(5), pp. 545–549 (1997). Physical Review Letters describes that 40% to 50% TMR ratio can be obtained up to an applied voltage of about 1 V in Co/SrTiO3/La0.7Sr0.3MnO3.

Ferromagnetic tunnel magnetoresistive devices and magnetic head

Hitachi Global Storage Technologies Japan, Ltd.


Linkers for binding drugs to cell binding agents are modified to hydrophilic linkers by incorporating a polyethylene glycol spacer. The potency or the efficacy of the cell-binding agent-drug conjugates is surprisingly enhanced several folds in a variety of cancer cell types, including those expressing a low number of antigens on the cell surface or cancer cells that are resistant to treatment. A method for preparing maytansinoids bearing a thioether moiety and a reactive group which allows the maytansinoid to be linked to a cell-binding agent in essentially a single step is also provided.

Antibody conjugates of cytotoxic drugs are being developed as target-specific therapeutic agents. Antibodies against various cancer cell-surface antigens have been conjugated with different cytotoxic agents that inhibit various essential cellular targets such as microtubules (maytansinoids, auristatins, taxanes: U.S. Pat. Nos. 5,208,020; 5,416,064; 6,333,410; 6,441,163; 6,340,701; 6,372,738; 6,436,931; 6,596,757; 7,276,497), DNA (calicheamicin, doxorubicin, CC-1065 analogs; U.S. Pat. Nos. 5,475,092; 5,585,499; 5,846,545; 6,534,660; 6,756,397; 6,630,579). Antibody conjugates with some of these cytotoxic drugs are actively being investigated in the clinic for cancer therapy (Richart, A. D., and Tolcher, A. W., 2007, Nature Clinical Practice, 4, 245-255).
The antibody-cytotoxic agent conjugates typically are prepared by the initial modification of reactive moieties on antibodies, such as lysine amino groups, or cysteine groups (generated by reduction of native disulfide bonds or by engineering of additional non-native cysteine residues on to antibodies using molecular biology methods). Thus antibodies are first modified with a heterobifunctional linker reagent, such as those previously described, exemplified by SPDB, SMCC and SIAB (U.S. Pat. No. 6,913,758 and U.S. Patent Publication No. 20050169933) to incorporate a linker with a reactive group such as mixed pyridyldisulfide, maleimide or haloacetamide. The incorporated reactive linker group in the antibody is subsequently conjugated with a cytotoxic agent containing a reactive moiety such as a thiol group. Another conjugation route is by reaction of a cytotoxic agent derivative containing a thiol-reactive group (such as haloacetamide, or maleimide) with thiol groups on the cell-binding agent. Thiol groups are incorporated on cell-binding agents such as an antibody by reduction of native disulfide residues (R. Singh et al., Anal. Biochem., 2002, 304, 147-156), or reduction of incorporated disulfide moieties (via SPDP, succinimidyl 3-(2-pyridyldithio)propionate, followed by reduction with dithiothreitol, D. G. Gilliland et al., Proc. Natl. Acad. Sci. USA., 1980, 77, 4539-4543), or by incorporation of additional non-native cysteine residues (J. B. Stimmel et al., J. Biol. Chem., 2000, 275, 30445-30450), or incorporation of thiol groups by reaction with 2-iminothiolane (R. Jue et al., Biochemistry, 1978, 17, 5399-5406), or methyl 3-mercaptopropionimidate ester (T. P. King et al., Biochemistry, 1978, 17, 1499-1506).
The antibody-cytotoxic agent conjugates with disulfide or thioether linkages are cleaved intracellularly, presumably in lysosomes, to deliver the active cytotoxic agent inside the cancer cell (H. K. Erickson et al., 2006, Cancer Research, 66, 4626-4433). In addition to the killing of target cells, antibody-cytotoxic agent conjugates with reducible disulfide linkage also kill proximate antigen-negative cells in mixed populations of antigen-negative and antigen-positive cells in vitro and in vivo in xenograft models, suggesting the role of target-cell released cytotoxic agent in improving potency against neighboring non-antigen-expressing cells in tumors with heterogeneous antigen expression (Y. V. Kovtun et al., Cancer Research, 2006, 66, 3214-3221).
Although, antibody-cytotoxic drug conjugates show cell killing activity in vitro and anti-tumor activity in vivo, their potency is diminished in many cases, especially when the antigen expression on the target cancer cell is low, or when the target cells are resistant to the treatment. This is often the case in the clinical setting, resulting in low to modest anti-tumor activity in patients. A potential approach to try to circumvent resistance is to synthesize new drugs that bear hydrophilic or lipophobic functionalities (see G. Szokacs et al., Nature Reviews, 5; 219-235, 2006). However, this process is cumbersome and several analogs have to be synthesized, and often modification in the structure of the drug results in loss of biological activity. Thus, there is a need for a different approach.
The method described in the art for preparing a cytotoxic conjugate of a cell binding agent and a drug via non-cleavable linker requires two reaction steps (U.S. Pat. No. 5,208,020 & US Publication No. 2005/0169933). First, the cell binding agent, such as an antibody, is modified with a bifunctional crosslinker that undergoes reaction with the reactive groups of the cell binding agent, such as the amine group on lysine residues or the sulfhydryl group on cysteine residues, to form covalent chemical bonds. Following modification of the cell binding agent, the product is purified to separate the desired modified cell binding agent from unreacted crosslinker. In a second step, known as a conjugation step, a reactive drug derivative, such as a thiol-containing maytansinoid, is added to the modified cell-binding agent for reaction with the modified cell-binding agent. Following this reaction, an additional purification is required to remove any unreacted drug species and other byproducts from the final conjugate. These multiple reaction and purification steps result in low yield of the final conjugate and can be expensive and cumbersome when one considers implementing these steps on a large scale. An additional drawback to these methods is the conjugate heterogeneity that is introduced when unreacted crosslinker remains linked to the cell-binding agent without attached drug. The unreacted crosslinker can then undergo additional side reactions such as hydrolysis and intramolecular or intermolecular reactions. There is therefore a need for functionalized, reactive drug derivatives, such as maytansinoids, that can be covalently linked via a non-cleavable bond to a cell binding agent, such as an antibody in essentially one reaction step.

Potent conjugates and hydrophilic linkers


A device and method prevents the imbalance of emission timing between strong key strokes and weak key strokes in an automatic performing piano by preventing the occurrence of reverse phenomenon and overlap phenomenon by correcting cessation timing according the order or sequence of key strokes. A reverse phenomenon, where cessation timing for one key stroke precedes its counterpart emission timing, is prevented by changing cessation timing to occur after emission timing. An overlap phenomenon, where emission timing for the latter of two successive strokes precedes cessation timing for the former stroke, is prevented by changing the cessation timing to occur prior to the emission timing. The method and device thus achieves reproduction of performance with balanced and controlled sound emission timing and high fidelity in performance reproduction.

This invention relates to a method and device for controlling sound emission in an automatic performing piano, and more specifically to such a piano which is immune from inaccuracy of performance in sound reproduction due to the time lag of emission of sound caused by variations in intensity of depressed keys.
A conventional automatic performing piano has suffered from imbalance of sound emission timing between strong strokes and weak strokes. This is due to the time period from a depress-key command (on-event) to actual emission of sound during which a solenoid is energized.
Some prior art methods try to solve this problem by adopting a sound prohibited time period T1, FIG. 12, in designing the amount of electric power L.sub.drv to be supplied to the solenoid for depressed keys. In FIG. 12, L.sub.1 is an original voltage level, L.sub.2 a start-up voltage level, and L.sub.3 is a holding voltage level. T.sub.2 is a time period to sustain the start-up voltage level. The sound prohibited time period T.sub.1, as shown in FIG. 12, is provided at the first stage of the chart of electric power L.sub.drv in order to correct the emission timing. The sound prohibited time period T.sub.1 is determined according to depression intensity data included in depression data such that the stronger the stroke is, the longer the duration of sound prohibited time period T.sub.1. The maximum value of the sound prohibited time period T.sub.1 is 100 milliseconds.
However, determination of the sound prohibited time period T1 simply according to the depression intensity data results in the following two undesirable phenomena.
One is a "reverse phenomenon" which is often caused by one strong but short key stroke. Since the sound prohibited time period T1 drags on because of the intensity of the key stroke, the off-event command in response to the release of the same key may precede the start up of the driving power. In reproduction of hora staccato notes, with a sound emission time period of only 30 milliseconds for each of the key strokes, this "reverse phenomenon" may occur, thus resulting in failure to reproduce the performance.
The other undesirable phenomenon is an "overlap phenomenon". When a strong key stroke on one key is immediately followed by a weak key stroke on the same key, the off-event for the strong key stroke may be caused after the expiration of the sound prohibited time period T1 for the weak key stroke, thus hampering reproduction of successive key strokes on the same key.

Method and device for preventing imbalance of sound emissions in an automatic performing piano


An apparatus for horizontal surface cleaning includes a cleaning head for engaging horizontal surfaces to be cleaned, a handle pivotally engaging the cleaning head for grasping during horizontal surface cleaning, and a tank affixed to the handle and pivotal therewith relative to the cleaning head. The tank is adapted to contain a surface cleaning liquid. The handle and tank have together an upright orientation during storage and a tilted orientation during horizontal surface cleaning. The tank includes a valve that closes during the upright orientation to prevent the liquid from exiting the tank, and opens during the tilted orientation to allow the liquid to exit the tank. The tilted orientation is caused during horizontal surface cleaning.

The invention may be embodied by or practiced using an apparatus for the cleaning of surfaces, having a power cord detachable from the apparatus, a cleaning head having a heating plate, and a cleaning pad, wherein the heating plate forms a planar underside of the cleaning head and includes a heating element to heat the planar underside when the power cord energizes the heating element. The cleaning pad may be removably attached against and in thermal communication with the planar underside such that the cleaning pad is heated to a temperature between 85 C and 100 C, inclusive, when the power cord energizes the heating element. And the heating element may not heat the planar underside and the cleaning pad may not be heated whenever the power cord is detached from the apparatus. The cleaning pad may be a pre-moistened fabric pad.
This apparatus may further have a cleaning head including the heating plate and the cleaning pad, and an elongate body having a handle at a proximal end thereof, wherein the cleaning head may be flexibly disposed at a distal end of the elongate body.
The invention may alternatively be embodied by or practiced using an apparatus for the hot and moist cleaning of surfaces, having a water reservoir, and a cleaning head having a heating plate and a cleaning pad, wherein the heating plate forms a planar underside of the cleaning head and includes a heating element to heat the planar underside. The water reservoir may be adapted to moisten the cleaning pad when the planar underside is above approximately 85 C. The cleaning pad may be removably attached against and in thermal communication with the planar underside such that the cleaning pad is moistened and heated to a temperature between 85 C and 100 C, inclusive. And the heating plate may not substantially heat water from the water reservoir prior to the moistening of the cleaning pad.
This alternative apparatus may further have a thermally-actuated valve to control the moistening of the cleaning pad by the water reservoir. The thermally actuated valve may be configured to open at approximately 85 C or above to allow water from the water reservoir to the cleaning pad. The thermally actuated valve may have a valve stem having an open position for allowing water from the water reservoir to the cleaning pad, and a closed position for denying water from the water reservoir to the cleaning pad, and a bimetal actuator which changes shape according to temperature change and moves the valve stem between the open and closed positions accordingly.
This alternative apparatus may further have an elongate body including a handle at a proximal end thereof, wherein the cleaning head is flexibly disposed at a distal end of the elongate body. The water reservoir may be disposed on the elongate body above the cleaning head, and may be adapted to moisten the cleaning pad by gravitational force when the valve stem is in the open position.
This alternative apparatus may further have a thermostat electrically connected to the heating element and adapted for sensing the temperature of the planar underside to maintain the temperature of the cleaning pad between 85 C and 100 C, inclusive.
This alternative apparatus may further have a thermo-fuse electrically connected to the heating element and adapted for sensing the temperature of the planar underside to disable the apparatus when an abnormally high temperature is sensed.
Additionally, the invention may alternatively be embodied by or practiced using an apparatus for the hot and moist cleaning of floors having an elongate body including a handle at a proximal end thereof and a water reservoir; and a cleaning head flexibly disposed at a distal end of the elongate body and having a heating plate and a cleaning pad, wherein the heating plate forms a planar underside of the cleaning head and includes a heating element to heat the planar underside. The water reservoir may be adapted to moisten the cleaning pad when the planar underside is above 85 C. The cleaning pad may be removably attached against and in thermal communication with the planar underside such that the cleaning pad is moistened and heated to a temperature between 85 C and 100 C, inclusive. And the heating plate may not substantially heat water from the water reservoir prior to the moistening of the cleaning pad.
This additionally alternative apparatus may further have a thermally-actuated valve to control the moistening of the cleaning pad by the water reservoir. The thermally actuated valve may be configured to open at approximately 85 C or above to allow water from the water reservoir to the cleaning pad. The thermally actuated valve may have a valve stem having an open position for allowing water from the water reservoir to the cleaning pad, and a closed position for denying water from the water reservoir to the cleaning pad, and a bimetal actuator which changes shape according to temperature change and moves the valve stem between the open and closed positions accordingly. The water reservoir may be disposed on the elongate body above the cleaning head, and may be adapted to moisten the cleaning pad by gravitational force when the valve stem is in the open position.
This additionally alternative apparatus may further have a thermostat electrically connected to the heating element and adapted for sensing the temperature of the planar underside to maintain the temperature of the cleaning pad between 85 C and 100 C, inclusive.
This additionally alternative apparatus may further have a thermo-fuse electrically connected to the heating element and adapted for sensing the temperature of the planar underside to disable the apparatus when an abnormally high temperature is sensed. This additionally alternative apparatus may further have a trigger-actuated valve in fluid communication with the water reservoir and thermally-actuated valve to selectively allow or deny water from the water reservoir to the thermally-actuated valve.
The invention may also be embodied by or practiced using an apparatus for horizontal surface cleaning having; a tank adapted for containing a surface cleaning liquid and having an upright orientation during storage and a tilted orientation during horizontal surface cleaning, and a gravity-actuated valve cooperating with the tank to prevent the liquid from exiting the tank during the upright orientation and allowing the liquid to exit the tank during the tilted orientation. The horizontal surface cleaning may require the tank to assume the tilted orientation. The apparatus may include a power cord detachable from the apparatus, a cleaning head having a heating plate, and a cleaning pad; wherein the heating plate forms a planar underside of the cleaning head and includes a heating element to heat the planar underside when the power cord energizes the heating element. The cleaning pad may be removably attached against and in thermal communication with the planar underside such that the cleaning pad is heated to a temperature between 85 C and 100 C, inclusive, when the power cord energizes the heating element, and the heating element may not heat the planar underside and the cleaning pad is not heated whenever the power cord is detached from the apparatus.
The cleaning pad may be fabric pad. The cleaning head may include the heating plate and the cleaning pad. The apparatus may further include an elongate body having a handle at a proximal end thereof, wherein the cleaning head is flexibly disposed at a distal end of the elongate body, and wherein the elongate body is tilted during horizontal surface cleaning.
The invention may also be embodied by or practiced using an apparatus for horizontal surface cleaning having a cleaning head for engaging horizontal surfaces to be cleaned, a handle pivotally engaging the cleaning head for grasping during horizontal surface cleaning, and a tank affixed to the handle and pivotal therewith relative to the cleaning head, the tank adapted to contain a surface cleaning liquid. The handle and tank may have together an upright orientation during storage and a tilted orientation during horizontal surface cleaning, and the tank may include a valve that closes during the upright orientation to prevent the liquid from exiting the tank, and opens during the tilted orientation to allow the liquid to exit the tank. The tilted orientation may be caused during horizontal surface cleaning.
The cleaning head may include a heating plate and a cleaning pad; wherein the heating plate forms a planar underside of the cleaning head and includes a heating element to heat the planar underside. The tank may be adapted to selectively moisten the cleaning pad when the planar underside is above approximately 85 C. The cleaning pad may be removably attached against and in thermal communication with the planar underside such that the cleaning pad is moistened and heated to a temperature between 85 C and 100 C, inclusive. And the heating plate may not substantially heat water from the tank prior to the moistening of the cleaning pad. A thermally-actuated valve may control the moistening of the cleaning pad by the tank. The thermally actuated valve may be configured to open at approximately 85 C or above to allow water from the tank to the cleaning pad. The thermally actuated valve may include a valve stem having an open position for allowing water from the tank to the cleaning pad, and a closed position for denying water from the tank to the cleaning pad, and a bimetal actuator which changes shape according to temperature change and moves the valve stem between the open and closed positions accordingly.
An elongate body may include the handle at a proximal end thereof, wherein the cleaning head is flexibly disposed at a distal end of the elongate body. The tank may be disposed on the elongate body above the cleaning head, and may be adapted to moisten the cleaning pad by gravitational force when the valve stem is in the open position and the tank and handle are in the tilted orientation. A thermostat may be electrically connected to the heating element and adapted for sensing the temperature of the planar underside to maintain the temperature of the cleaning pad between 85 C and 100 C, inclusive. A thermo-fuse may be electrically connected to the heating element and adapted for sensing the temperature of the planar underside to disable the apparatus when an abnormally high temperature is sensed.
The invention may also be embodied by or practiced using an apparatus for floor cleaning, having an underside having a perimeter edge, a cleaning pad, and fasteners for affixing the cleaning pad to the underside. The cleaning pad may include a main portion for floor cleaning and a tab extending there-from beyond the perimeter edge when the cleaning pad is affixed to the underside, for engaging to remove the cleaning pad from the underside without engaging the main portion. The apparatus may be adapted to wet the main portion of the cleaning pad during floor cleaning and the tab may be of a non-absorbent material which remains dry when the main portion is moistened. The fasteners may be hook/loop fasteners affixed to the underside and the main portion may include hook/loop fabric.
The invention may also be embodied by or practiced using a cleaning pad for an apparatus for floor cleaning, the apparatus of the type having an underside having a perimeter edge and fasteners for affixing the cleaning pad to the underside. The cleaning pad may include a main portion for floor cleaning and a tab extending there-from beyond the perimeter edge when the cleaning pad is affixed to the underside, for engaging to remove the cleaning pad from the underside without engaging the main portion. The tab may be of a non-absorbent material which remains dry if the main portion is moistened. The fasteners of the apparatus may be hook/loop fasteners affixed to the underside, and the main portion may include hook/loop fabric.
Further features and aspects of the invention are disclosed with more specificity in the Detailed Description and Drawings provided herein and showing exemplary embodiments of the invention.


A circuit board includes a pad, a transmitting trace and a plating bar. The plating bar is used for forming an electroplating metallic layer on the pad, the pad and the transmitting trace are used for the signal transmission. Due to the plating bar causes a noise during the signal transmission, a dielectric layer having at least one opening is adjacent to at least one side of the plating bar to reduce the equivalent dielectric permittivity thereof and to maintain signal transmitting quality.

1. Field of Invention
The present invention relates to a circuit board, and more particularly to a circuit board with plating bar.
2. Related Art
Accompanying to the development of corresponding technologies of electronic industry and the shrinkage in dimensions of the product, the IC designer and the IC manufacturers face to many challenges in process such a compact product. One of those challenges is more pads and conductive traces formed on the surface of the circuit board for signal or power transmission. In the conventional circuit board, a nickel/gold (Ni/Au) layer is generally covered on the surface of the pad. Thus, the golden wire and the pad of the circuit board are easily joined together during the wire bonding process. Similarly, the soldering pad, which is typically made of copper, of the packaging substrate is covered by the Ni/Au layer to prevent against oxidization and to improve the quality of electrical and mechanical connection of the solder balls.
The electroplating process is to form a metallic layer by electrolysis. A metal sheet for plating conductive layer acts as an anode, the electrolyte is an ion solution containing metallic ions, and the plated object acts as a cathode. The metallic ions in the electrolyte are attracted and moved to cathode after applying voltages to anode and cathode. The metallic ions are then plated on the plated object after reduction. In order to form the conductive layer, a plurality of plating bars are needed to be disposed on the circuit board for electrically connecting the pads with cathode through the plating bars.
As shown in FIGS. 1a and 1b, a conventional circuit board 100 has a plurality of pads 111 acting as electrical connections of the circuit board 100 and a device (not shown). The pad 111 is a wire bonding pad or a soldering pad, which may connect to another device on the same surface through a transmitting trace 112, and may also connect to a conductive via 150 through the transmitting trace 112 for connecting with an internal circuit of the circuit board 100.
As shown in FIG. 1b, the circuit board 100 includes four conductive layers and three dielectric layers 101, 102 and 103. The conductive layers are respectively isolated by one dielectric layer. In the prior art, the top conductive layer and the bottom conductive layer of the circuit board 100 are generally used for disposing signal layout and the pads 111. The intermediate conductive layers 120 and 130 act as the reference planes, for example the conductive layer 120 is a power plane and the conductive layer 130 is a ground plane. The circuit board 100 has a through hole 105. A conductive via 150 is formed by disposing a conductive material on side wall of the through hole 105 for electrically connecting between different conductive layers. The transmitting trace 112 is for example connected to a transmitting trace 141 on the other side of the circuit board 100 through the conductive via 150. A signal is thus transmitted to another device (not shown) through the signal transmitting structure including the pad 111, the transmitting trace 112, the conductive via 150 and the transmitting trace 141.
The pad 111 includes at least one electroplating metallic layer such as Ni/Au layer is formed by a plating process. In order to electrically connect the pad 111 to a plating electrode during the plating process, the signal transmitting path is connected to a plating bar 160. In FIG. 1a, the plating bar 160 is connected to the transmitting trace 112 or the conductive via 150. The plating bar 160 may be located at another conductive layer different from that of the pad 111. In FIG. 1b, a plating bar 160 on the power plane 120 is connected to a pad 111 through the conductive via 150. In addition, the plating bar 160 will also extend to an edge 104 of the circuit board 100.
However, the layout for a plurality of plating bars will occupy the available area for circuit layout. The signal transmitting path needs not to pass the plating bar in the signal transmitting structure, that is, the signal transmitting structure has an open stub. The open stub effect of redundant plating bars causes the impedance of the signal transmitting path is not matched during the application of high frequency, causes a noise during the signal transmission, and lowers signal transmitting quality.
In spite of other solutions have been disclosed in the prior art, which include forming the conductive layers without plating or removing the plating bars in the following process. However, these solutions cause the limitation to circuit design and the increasing to production cost. It is therefore an important subject of the present invention to provide a circuit board to reliably and effectively reduce the influence of the plating bar to the signal transmitting structure.


An athletic shoe coating for traction enhancement includes a pressure sensitive adhesive (PSA) and a tackyfying resin and a film former initially in solution within a solvent suitable for application to the surface of a shoe sole in liquid form, such as by spraying, rolling and brushing the solution onto the shoe sole. After the solvent evaporates a film or coating attaches or is bonded to the shoe sole that exhibits the property of dynamically modifying the traction properties of the shoe sole when pressure and shear forces are applied to the coating. Such modification causes the exterior surface of the film or coating to “refresh” the exposed surface upon impact. This imparts continued tackiness over extended use. Impact modifiers may be added for controlled release of a solvent to temporarily dissolve or soften the film or coating to promote such refreshment of the coating outer surface.

1. Field of the Invention
The invention generally relates to athletic shoes and, more specifically, to a coating applied to the soles of athletic shoes for traction enhancement.
2. Description of the Prior Art
Specialized shoes have been designed and used in conjunction with many athletic activities, such as basketball, tennis, volleyball, etc. These shoes are designed not only to provide support to the player but to enhance the "cutability" performance of the shoes when a player is required to step "hard" on the shoes to stop quickly, pivot or reverse directions.
Indoor floor sport enthusiasts have one major complaint—dusty, dirty floor surfaces. Players use courts that range from slightly dusty to neglected for months. These conditions lead to a lack of traction at the most inopportune times, i.e., when turning suddenly or attempting to make fast cuts, initial accelerating steps and immediate stops.
Basketball and volleyball courts, for example, are hard surfaces that are generally maintained to provide very smooth surfaces. Such smooth hard surfaces when covered with dust tend to diminish the amount of traction that a shoe sole can provide, particularly when the bottom surface of the sole of the shoe becomes contaminated by collecting dust, fibers and other forms of debris. Such debris often sticks to the sole of a player's shoe and this diminishes and eventually leads to a significant reduction or loss of traction between the player's shoe sole and the floor surface. Such dust accumulates rather quickly in spite of all attempts to keep the floor dust free. Players often find it necessary to wipe the bottoms of their shoes quite frequently, with their hands or other devices in order to restore some of the original tackiness of their shoes.
A number of solutions for aforementioned problem have been proposed. U.S. Pat. No. 3,400,421, for example, discloses a shoe sole cleaner in a form of a "sticky" floor mat that incorporates a pressure sensitive adhesive (PSA) to accumulate dirt from the bottom of shoes. Once the sticky surface has been fully contaminated and can no longer adequately serve its purpose a new layer is created by peeling the top pressure sensitive sheet in a stack of such sheets. Thus, such shoe sole cleaner utilizes a pressure sensitive adhesive surface that a user can walk on to clean the under surface of shoes thereby removing some of the debris and micro-debris that has been accumulated and attached to the shoe sole. This is not always practical when playing sports.
U.S. Pat. No. 5,421,106 discloses a shoe sole wiping pad that seeks to eliminate the problem encountered on the floors of basketball courts and the like where there is a constant accumulation of dust particles that attach to the bottoms of shoes of basketball players, for example, resulting in loss of traction during a game. The patent discloses an upwardly facing wiping surface of suede or other suitable material that can be used by players to remove dust from their shoe soles by wiping the shoe soles on the upwardly facing surface of a shoe string cover mounted in each instep of each shoe.
In U.S. Pat. No. 5,555,564 an apparatus is disclosed for cleaning a shoe sole and a method of making and using the same. A shoe sole wiping pad is sewn into the outer surface of an athletic socks upper tube portion. The wiping pad absorbs and retains moisture and has a moisture-bearing wiping surface that removes dust and debris from the sole of an athletic shoe when the wearer wipes the sole across the pad.
In U.S. Pat. No. 7,337,561 a shoe sole traction enhancement device is disclosed intended to enhance the traction between a sole of a shoe and a hard court athletic surface. The patent discloses a number of different devices that include an adhesive roll that can be applied to the bottom surface of the shoe sole. The rolling process encourages the transfer of the particles from portions of the sole to the adhesive role, with the expectation that enough dust and debris is removed from the shoe sole to at least slightly enhance the traction between the shoe sole and the athletic surface.
In the aforementioned patents the emphasis is to apply a device to the shoe sole surface so that either rubbing the device against the shoe sole or the shoe sole rubbing against the device removes dust and/or other debris from the bottom of the shoe in order to restore some of the tackiness of the shoe sole. The problem with the proposed devices is that removing debris from the bottom of the shoe sole offers little to no added traction, beyond that of a clean shoe and lasts for only a short period of time. The sole will continue to attract dust and other debris that will stick to the shoe sole. With extended pounding the debris at least partially penetrates the surface of the sole and becomes embedded or lodged in the sole so that it is difficult to remove by physically rubbing the surface.
There are several products on the market today that attempt to address the issue of shoe adhesion including PYTHON™ solvent spray for shoe outsoles, SNEAKER GRIP™ spray for restoring flexibility of rubber outsoles, CRAMMERS ROSIN™ powdered rosin, B SHARP™ shoe sole cleaner for improving traction, SNEAKER GRIP SPRAY™ spray for restoring flexibility of rubber outsoles. SHOE GRIP™ spray-on adhesive to prevent slips and falls on ice and slippery surfaces, and SLIPP NOTT™ rubber and plastic mats for removing dust and dirt from athletic shoes in order to enhance traction and they can be broadly divided into two classes. The first are shoe-cleaning products, such as B SHARP™ which, while effective at cleaning, do not provide any modification of the shoe's original or current grip. Further, they are very short lived as they do not address the conditions of the court and as soon as the player takes a few steps all of the benefits of cleaning are lost. Watching any court event including basketball, volleyball, table tennis, squash, or racquetball games, as well as, cheerleading competitions one will notice players repeatedly wiping the soles of their shoes with their hands throughout the game. The second type of product attempts to modify the adhesion properties of the sole. There are far fewer of this type of product and those that exist are not designed for indoor use. Perhaps the most well-known is SHOE GRIP™, a product designed for outdoor adhesion between boots and cold surfaces. It employs a low melting point, room-temperature liquid rosin acid which, upon loss of the water (which requires at least 10 minutes), leaves behind a very sticky liquid rosin product. This is completely unacceptable for indoor athletic use as it would mar the floor and leave a sticky residue everywhere.

This patent is subject to a terminal disclaimer.

Athletic shoe sole coating for traction enhancement


Embodiments disclose a non-roll foam EarTip that may provide for fingertip press-in insertion, improved comfort, simplicity of use, flatter attenuation and/or improved hygienic properties, by way of non-exclusive example. A hollow foam body typically encompasses a shorter stem of more rigid material, and in some embodiments the foam body has a tighter skin on the inner and outer surfaces. In some embodiment, the EarTip is an earplug formed of polyurethane foam with a dense skin on the inner and outer surfaces of the hollow body, and having a plurality of splines in the cavity.

In very noisy environments, workers often wear earplugs or other hearing protection designed with high noise blocking capabilities (such as a noise reduction rating or NRR at or around 33). But in moderately noisy environments, a lower level of hearing protection (with NRR in a range of 20 to 30, by way of example) may be sufficient to effectively offer protection from background noise in the workplace. Such lower NRR levels can also be useful in moderately noisy environments, because they may allow workers to have some ability to hear useful, non-dangerous sounds, while still being adequately protected from long-term background noise that could lead to hearing damage. By way of example, it may be useful for workers to be able to hear a supervisor or co-worker shouting over the background noise, allowing for some verbal communication in the moderately noisy workplace which may improve work efficiency and workplace safety.
Allowing such useful sounds through to the user, while blocking out damaging levels of sound exposure in accordance with OSHA or other health regulations, may also help workers be able to leave the hearing protection in place throughout the day (since some necessary communication may be possible without the need to remove the earplugs). This may further help to ensure that the workers are adequately protected from damaging workplace background noise exposure, since workers will not need to remove the earplugs in order to communicate (which would expose them to damaging levels of sound for a period of time without any hearing protection), and since workers will not have to remove and replace the earplugs throughout the workday as they try to communicate (which could lead to improper insertion of the earplug in a manner that does not offer sufficient protection, since the earplugs would then be inserted in less than ideal circumstances). It also may be important to ensure that hearing protection is not so complete that workers would be unable to hear alarms or other audible warning signals.
Applicant has also found that, while press-in (non-rolldown) earplugs may be considered simpler to insert by many users and may typically be less prone to soiling (since they are handled less by users), comfort concerns may need to be addressed; the stiffness often needed for effective push-in insertion may cause discomfort. Applicant has also found that standard press-in type earplugs with extended handles (in which the more rigid handles protrude from the foam earplug) may be unsatisfactory in several ways. For example, the handles tend to produce a level of discomfort when the handle contacts the ear canal wall and/or comes into direct contact with external portions of the concha. Indeed, the extended handles may also come into contact with external objects as they jut out from the user's ear, making their use difficult in conjunction with some hats, helmets, glasses, etc, and creating a safety risk since exterior objects could inadvertently contact the handle and drive the earplug too deep within the ear canal. Additionally, extended handles tend to produce a level of resonance that may negatively affect the sound attenuating properties of these earplugs (with the handles acting similarly to a tuning fork). Thus, Applicant has considered techniques that may improve comfort while allowing for effective insertion of the earplug in a user's ear canal.


Human Bone Morphogenic Protein 7 (hBMP-7) variant peptide chains, nucleic acids encoding these peptide chains, and methods of making and using the foregoing are disclosed.

Human Bone Morphogenic Protein 7 (hBMP-7) is a member of the TGF-β superfamily of proteins and has recognized therapeutic potential as both a modulator of bone structure and renal function (Klahr, J. Nephrol. 16:179-185 (2003)). For example, active hBMP-7 could be used as a protein therapeutic in indications such as myelofibrosis, idiopathic pulmonary fibrosis, renal osteodystrophy, renal fibrosis, diabetic nephropathy, chronic obstructive pulmonary disorder (COPD), and osteoarthritis.
hBMP-7 is transcribed as mRNA containing a 1293 base pair open reading frame (the corresponding cDNA is shown at SEQ ID NO: 1) which is translated as a precursor protein of 431 amino acid residues (FIG. 1; SEQ ID NO: 2) that is proteolytically processed. The hBMP-7 precursor protein contains a signal peptide spanning residues 1 to 29 of SEQ ID NO: 2, a prodomain spanning residues 30-292 of SEQ ID NO: 2, and a mature form domain spanning residues 293-431 of SEQ ID NO: 2 (FIG. 1).
Proteolytic processing of the hBMP-7 precursor protein is believed to occur in several steps. First, the signal peptide directs hBMP-7 to the endoplasmic reticulum of the cell where folding occurs and hBMP-7 forms a homodimeric protein complex. Next, the hBMP-7 prodomain is removed by proteolytic processing to produce a covalently linked homodimer consisting of two antiparallel hBMP-7 mature domain peptide chains. This final homodimeric protein complex is the biologically active form and secreted by cells.
Secreted hBMP-7 interacts with surface receptors on other cells and soluble antagonists, such as ActRII, BMPR1a, and Noggin to mediate its biological effects and activity. Structural information concerning these interactions can be derived from a number of different BMP-7 crystal structures (Greenwald et al., Mol. Cell. 11:605-017 (2003); Griffith et al., PNAS. 93:878-883 (1996); Keller et al., Nat. Struct. Mol. Biol. 5:481-488 (2004); Groppe et al., Nature. 420(6916):636-642 (2002).
Although hBMP-7 (formerly known as osteogenic protein 1 (OP-1) by Ozkaynak et al. (EMBO J. 9(7), 2085-2093 (1990)) has been known at least since 1990, to date several unresolved problems have prevented its development as a therapeutic protein. First, recombinant expression of hBMP-7 in mammalian cells is extremely low relative to other proteins of similar size. This is incompatible with the large-scale commercial production and purification needed for therapeutic use of hBMP-7. Second, proteolytic processing of the mature domain of hBMP-7 can occur at any of four different sites in that domain. This results in a number of different mature forms of hBMP-7 being produced during the recombinant expression of this protein. This high degree of heterogeneity in the expressed protein is highly undesirable in a protein therapeutic. Third, the mature form of hBMP-7 has poor solubility at pH values near 7.0; thus, acidic pH values are required to maintain hBMP-7 solubility. However, acidic pH values are incompatible with most common delivery methods, such as intravenous injection, used to administer protein therapeutics to patients. Lastly, the prodomain of hBMP-7 associates non-covalently with the mature domain of hBMP-7. Thus, purifying the prodomain away from the mature domain of hBMP-7 is relatively difficult and is incompatible with large-scale commercial production and purification.
Thus, a need exists for hBMP-7 variant peptide chains with improved properties that are suitable for use as therapeutic proteins and are compatible with large-scale commercial production and purification.

BMP-7 variant compositions, methods and uses


A method and apparatus for data modulation in an antenna array include: storing input data comprising of a plurality of data bits, in a buffer; generating a pseudo random number; computing a transmission mode from the pseudo random number; based on the computed transmission mode and the number of antenna elements in the antenna array, computing a particular phase offset for each antenna element; sequentially providing the stored input data, one bit at a time, to each antenna element; and transmitting the input data from each antenna element according to the computed particular phase offset for said each antenna element.

There are ever increasing methods offered to improve privacy and spectral efficiency in wireless communications. For example, methods such as direct sequence spread spectrum communications, frequency hopped spread spectrum, and burst mode communications are just a few of the waveform solutions for enhanced privacy. Spectral efficiency is achieved by using modulation that is more efficient and coding techniques such as 128-QAM and Turbo codes respectively.
Spread spectrum techniques, which are widely used in signal communications, spread a signal with a relatively narrow bandwidth over a much wider bandwidth, 1000× greater for example. Some applications of spread spectrum includes communications privacy, increasing resistance to noise, interference and jamming of signals. It is also used to prevent signal detection and eavesdropping, and to limit power flux density, for example, in satellite downlink communications. Frequency hopping is one of the modulation techniques used in spread spectrum signal transmission.
In a frequency-hopping spread spectrum (FHSS) communication, radio signals are transmitted by rapidly changing carrier frequencies among many available frequencies, using a pseudorandom sequence known to both the transmitter and the receiver. The overall bandwidth required for frequency hopping is much wider than that required to transmit the same information using only one carrier frequency. However, because transmission occurs only on a small portion of this bandwidth at any given time, the power spectral density is reduced in proportion to the ratio of the hopping bandwidth to the instantaneous bandwidth.
The term mode refers to solutions to the Wave Equation. The Wave Equation is a second order partial differential equation whose solution describes the propagation mode of a wave. The wave equation has an infinite number of solutions, where each solution is a mode. For plane waves, mode zero is the solution. For non-plane waves, there are an infinite number of positive and negative integer solutions.


A concatenated equalizer/trellis decoding system for use in processing a High Definition Television signal. The re-encoded trellis decoder output, rather than the equalizer output, is used as an input to the feedback filter of the decision feedback equalizer. Hard or soft decision trellis decoding may be applied. In order to account for the latency associated with trellis decoding and the presence of twelve interleaved decoders, feedback from the trellis decoder to the equalizer is performed by replicating the trellis decoder and equalizer hardware in a module that can be cascaded in as many stages as needed to achieve the desired balance between complexity and performance. The present system offers an improvement of between 0.6 and 1.9 decibels. Cascading of two modules is usually sufficient to achieve most of the potential performance improvement.

1. Field of the Invention
This invention relates generally to the field of digital signal processing and more particularly to a concatenated equalizer/trellis decoder suitable for decoding multiple mode trellis encoded High Definition Television (HDTV) signals.
2. Background of the Invention
The Advanced Television Systems Committee (ATSC) standard for HDTV in the United States specifies an eight (eight levels per symbol) vestigial sideband (VSB) transmission system as described in the "ATSC Digital Television Standard", Document A/53 published on Sep. 16, 1995. This document sets forth all the requirements regarding HDTV signal characteristics. In the receiver, an equalizer is included which is an adaptive filter which receives the VSB data stream at an average rate equal to the symbol rate of approximately 10.76 MHz. The equalizer attempts to remove linear distortions mainly caused by multipath signal propagation, which is characteristic of terrestrial broadcast channels. One equalizer design suitable for use in an HDTV receiver is a decision feedback equalizer (DFE) as described in John G. Proakis, "Digital Communications", McGraw-Hill, 2nd edition, 1989, New York and in U.S. Pat. no. 6,493,409, entitled PHASE DETECTORS IN CARRIER RECOVERY FOR OFFSET QAM AND VSB, issued on Dec. 10, 2002 to Lin et al. A simplified block diagram of a typical DFE architecture is shown in FIG. 1. The DFE is seen to include a Feed Forward Filter (FFF), a Feedback Filter (FBF), a slicer, a lock detector and a mode switch, and is capable of operating in training, blind or decision directed (dd) modes.
The functions of the FFF, FBF and the slicer are well known and together they perform the basic functions of filtering and quantization. The lock detector compares the equalizer output and the slicer levels with a threshold, and in response to that operation generates an updated lock detector output. The mode switch chooses the appropriate input to the FBF filter as well as selecting the error and control signals to be used in performing the equalizer adaptation according to the current equalizer operating mode. The mode switch also examines the lock detector output. In normal operation, the equalizer mode switch has an automatic switching capability, which depends on the status of the equalizer lock detector. The mode switch assumes that the training and blind modes are used for convergence purposes only. After the equalizer lock detector senses convergence, the equalizer is then switched to the decision directed (dd) mode. Whenever convergence is lost, the mode switch returns the equalizer to the training or blind mode.
In the ATSC standard, a training sequence is included in the field sync signal in order to provide a mechanism for initial equalizer convergence. The received sequence of coded symbols serves as the input to a synchronization control unit, which detects field and segment synchronization patterns within the symbol sequence and generates the corresponding sync signals. In the training mode, the equalizer coefficients are only updated during the field sync pulse. The drawbacks of this method are that it requires the prior correct detection of the field sync, and since the training sequence is contained in the field sync, which occurs only once every 25 milliseconds, the rate of convergence is possibly decreased. In an environment of multiple reflected or ghost signals, or in other dynamic environments, the detection of the field sync may be difficult. In those situations the receiver needs some self recovering or blind method of initially adjusting equalizer tap coefficients without referring to the training sequence. Since a blind algorithm works with every data symbol it will also tend to have a faster rate of convergence. An example of a blind convergence algorithm is Godard's Constant Modulus Algorithm (CMA). See D. N. Godard, "Self-Recovering Equalization and Carrier Tracking in Two Dimensional Data Communication Systems", IEEE Transactions on Communications, Vol. COM-28, pp.1867-1875, November 1980. See also D. N. Godard, U.S. Pat. No. 4,309,770.
The final mode of equalizer operation, decision directed (dd), assumes that the input to the feedback filter (FBF) is the output of the slicer. Since the adaptation error and the input to the feedback filter are aided by the presence of the slicer, coefficient adaptation occurs throughout the data sequence. The dd mode does not have good convergence characteristics, but once convergence is achieved it has advantages when compared to the other modes of equalizer operation. The presence of the slicer data results in a reduced mean squared error (MSE) and bit error rate (BER) at the equalizer output when compared to operation in the blind mode. Since the dd mode updates its coefficients with every symbol rather than interpreting just the training symbols, the dd mode provides faster adaptation and tracking capabilities than the training mode.
Trellis coding is used in combination with other techniques to protect against interference from particular noise sources. Trellis coding requirements for HDTV are presented in sections 4.2.4-4.2.6 (Annex D), 10.2.3.9, 10.2.3.10 and other sections of the Digital Television Standards for HDTV Transmission of Apr. 12, 1995 prepared by the ATSC. The HDTV standard presents a trellis coding system that employs an interleaving function involving twelve parallel trellis encoders at a transmitter and twelve parallel trellis decoders at a receiver for processing twelve interleaved data streams. The trellis system employed utilizes a rate ⅔ trellis coded modulation (TCM) code. The code is implemented by coding one bit using a rate ½, four state convolutional encoder, and then adding an FEC uncoded bit which is differentially precoded. Each set of three coded bits produced by the encoder is mapped to an eight level VSB modulator symbol. FIG. 2 is a block diagram showing the differential precoder, trellis encoder and corresponding eight level VSB symbol mapper. The twelve identical encoders and precoders are used sequentially, processing each one byte at a time and subsequently transmitting one complete symbol at a time. For each encoder, the input data bits X1 and X2 are encoded as three bits Z2, Z1, and Z0. Each three-bit word corresponds to one of the eight symbols R. The input bit X2 is processed by a precoder to provide encoded bit Z2. The input bit X1 is encoded as two bits Z1 and Z0 by the trellis encoder. An example of a trellis decoder used in an HDTV receiver is disclosed in U.S. Pat. No. 5,841,478, entitled CODE SEQUENCE DETECTION IN A TRELLIS DECODER, issued on Nov. 24, 1998 to Hu, et al.
The use of DFE techniques has been the subject of controversy in the field of receiver design. While DFE offers a relatively simple method for equalizing a highly dispersive linear channel, it may suffer from error propagation, a mechanism whereby incorrect source symbol estimates may cause future decision errors leading to potentially lengthy error bursts. In the HDTV receiver, when the terrestrial channel introduces multipath and white noise, particularly when the multipath signal is strong and the signal to noise ratio (SNR) is low, error propagation in the feedback filter (FBF) of the equalizer (DFE) affects the performance at the output of the trellis decoder. Simulation of an ATSC receiver including a Decision Feedback Equalizer (DFE) for an HDTV terrestrial channel having strong multipath and Additive White Gaussian Noise (AWGN) shows that receiver performance can be improved if the decision directed mode is replaced by a soft decision directed mode, whereby the input to the FBF filter is the equalizer output instead of the slicer output. In addition, ideally the equalizer feedback filter should receive more accurate symbol decisions than those provided by the equalizer slicer.

Concatenated equalizer/trellis decoder architecture for an HDTV receiver


A crucible including a cylindrical partition member arranged concentrically therein for use in a silicon single crystal growing apparatus. The bottom of the crucible located on the inner side of the partition member has a thickness which is not less than 1.3 times and not greater than 4 times the thickness of the partition member and it also has a porosity which is between 0 and 0.2% in its inner layer and between 0.2 and 15% in its outer layer as compared with the porosity of the partition member which is 0.2% or less. By virtue of the foregoing, a D.F. ratio (ratio of dislocation free) of 80% or over can be expected.

1. Field of the Invention
The present invention relates to a silica glass crucible used for the manufacture of silicon single crystals according to the Czochralski method.
2. Description of the Prior Art
The method of manufacturing silicon single crystals according to the Czochralski method has heretofore been in use and it has become substantially a perfect technique.
As is well known, this technique is so designed that after molten silicon starting material has been contained in a silica glass crucible, a silicon seed crystal is brought into contact with the molten silicon surface and simultaneously the silicon seed crystal is slowly pulled while rotating it, thus growing a silicon single crystal along with the solidification at the contact surface between the pulled silicon single crystal and the molten silicon surface and thereby producing the cylindrical silicon single crystal.
At this time, in order that the silicon single crystal may become a P-type or N-type semiconductor in accordance with the intended use, the silicon starting material is mixed with a suitable amount of such dopant as boron, antimony or phosphorus. The ratio of such dopant taken into the crystal from the molten silicon (i.e., the segregation coefficient) is generally not greater than 1. The concentration of the dopant in the silicon single crystal determines its resistivity and therefore it should preferably be uniform in the crystal.
Also, besides the dopant which is intentionally introduced into the silicon single crystal as mentioned above, the presence of oxygen introduced unavoidably during the manufacture is not negligible. In other words, the concentration of the oxygen which is introduced into the silicon single crystal has a considerable influence on the characteristics and yield of a semiconductor product and the oxygen concentration should also be uniform throughout the upper part to the lower part of the single crystal.
However, as the pulling of the silicon single crystal proceeds, the molten silicon with the crucible is decreased and the concentration of the impurity is varied. In other words, since the segregation coefficient of the dopant is not greater than the dopant concentration of the molten silicon is increased gradually so that the silicon single crystal is varied in dopant concentration from the upper part to the lower part of the crystal. Also, since the oxygen concentration of the molten silicon is dependent on the amount of the oxygen released from the silica glass crucible into the molten silicon, the concentration of the oxygen introduced into the crystal is also varied with decrease in the molten silicon.
As mentioned previously, the quality of the pulled silicon single crystal is varied along the pulling direction. However, the product actually used as wafers is limited to the portions having dopant concentrations and oxygen concentrations in limited ranges. As a result, the extent of the pulled silicon crystal which can be used as the product is extremely limited.
Some methods have been proposed for the solution of these problems and the typical method which can be considered as practical is one employing a double-structure crucible.
In other words, Japanese Patent Publication No. 40-10184 discloses a method in which a concentric crucible adapted to be heated from the outer periphery thereof is so constructed that the molten silicon in an outer crucible is separated from the molten silicon on the inner side by a partition but the two are mutually communicated and a semiconductor crystal is pulled centrally while feeding the semiconductor starting material to the molten silicon on the outer side.
Referring to FIG. 10, there is schematically shown a silicon single crystal manufacturing apparatus employing a double structure crucible, and a crucible 22 and a partition member 23 are constructed integrally by using high-purity silica glass. Numeral 25 designates the molten silicon contained in the crucible 22, and 26 a silicon single crystal pulled from the surface of the molten silicon within the partition member 23. It is to be noted that the lower part of the partition member 23 is formed with a hole 24 to permit the molten silicon 25 to flow between the outer and inner sides of the partition member.
FIG. 10 is a schematic diagram showing the case in which the double structure crucible is incorporated in a batch-type silicon single crystal manufacturing apparatus. The molten silicon of a given dopant concentration is contained on the inner side of the partition member 23 and the molten silicon containing no dopant is contained on the outer side of the partition member 23. It is constructed so that a silicon single crystal 26 is pulled from the single flows to the single crystal growing section from the outer side of the partition member, hereby always maintaining uniform the concentration of the dopant within the single crystal growing section.
Referring now to FIG. 11, there is illustrated another type of construction in which while pulling a silicon single crystal from the single crystal growing section, powder starting material 29 is continuously fed to the starting material feed section from a starting material feed pipe 28 thereby maintaining constant the amount of the molten silicon within the single crystal growing section, and it has the object of maintaining constant the dopant and oxygen concentrations of the molten silicon in the single crystal growing section.
Where the double structure crucible is used to pull a silicon single crystal in accordance with such conventional technique, the heat environment in the molten silicon becomes directly opposite to the case in which the ordinary single structure crucible is used.
In the case of the CZ method using the ordinary single structure crucible, the crucible side wall portion is higher in temperature than the crucible bottom portion. In other words, the amount of heat supplied from the crucible side wall portion is greater than the amount of heat supplied from the crucible bottom portion. Reflecting this fact, it is said that the convection of the molten silicon within the silica glass crucible is predominated by the flows as shown in FIG. 8. If such convection of the molten silicon, there is less temperature variation at the solid-liquid interface between the silicon single crystal and growth is attained.
Where the pulling of a silicon single crystal is effected by using the double structure crucible, however, the amount of heat supplied to the single crystal growing section through the crucible side is supplied indirectly through the starting material feed section and therefore the proportion of the heat input through the crucible bottom is increased as compared with the case where the single-structure crucible is used. As a result, the temperature distribution in the double structure crucible becomes opposite to the case where the single structure crucible is used and therefore the maximum value of the temperature in the silica glass crucible surrounding the single crystal growing section is positioned at the crucible bottom portion. Its temperature distribution is such that the crucible bottom portion is high in temperature and the partition member wall surface is relatively low in temperature. Under such heat environment where proportion of the heat input through the bottom portion is large, the heat convection of the molten silicon within the single crystal growing section may possibly be predominated by the flow field as shown in FIG. 9 which is directly opposite to that shown in FIG. 8. Since such flow field is unstable, the high-temperature molten silicon at the crucible bottom portion is intermittently moved directly to the solid-liquid interface of the silicon single crystal so that the resulting heat variation causes defects in the silicon single crystal to be pulled and hence the occurrence of dislocations.
On the other hand, the pores included in the silica glass crucible may also be considered as a cause for impeding the stable pulling of the silicon single crystal. In other words, while the surface of the silica glass crucible is subjected to erosion by its reaction with the molten silicon, at this time the pores confined within the silica glass crucible break and enter into the molten silicon thus giving rise to a problem that dislocations are caused when the resulting bubbles and the broken pieces of silica glass the solid-liquid interface of the silicon single crystal.

Crucible for manufacturing single crystals