To obtain both the highest possible maximum operating frequency f.sub.max and early voltage V.sub.A, a semiconductor device provided with a bipolar transistor including a collector region, a base region formed on the collector region, an emitter region formed in contact with the base region, a base leading electrode connected to the base region, and an emitter electrode connected to the emitter region, is characterized in that a ratio Q.sub.B /N.sub.c of base Gunmel number Q.sub.B to impurity concentration N.sub.C of the collector region of the bipolar transistor lies within a range from 0.2.times.10.sup.-3 cm to 2.5.times..sup.-3 cm.

1. Field of the Invention
The present invention relates to a semiconductor device, and more specifically to the structure of a bipolar transistor usable in a high frequency analog field.
2. Description of the Prior Art
Recently, the operation speed of LSIs has been increased markedly. However, a further improvement in the operation speed of analog LSIs has been still required in the field of not only digital systems represented by large scale computers but also mobile communications systems, etc. As the semiconductor elements for constructing the analog LSIs, in general, silicon bipolar transistors are now widely used owing to the excellent linearity and the mass productivity.
When the analog LSIs are designed, the design factors such as cut-off frequency f.sub.T, maximum operating frequency f.sub.max early voltage V.sub.A, etc. of the bipolar transistor must be considered as the indices of the high speed performance of the analog LSIs. Conventionally, however, in order to improve the high speed performance of the bipolar transistor with priority, there exists such a tendency that the maximum operating frequency f.sub.max has been improved by increasing the cut-off frequency f.sub.T as high as possible at the sacrifice of the early voltage V.sub.A.
Therefore, conventionally, in order to increase the cut-off frequency f.sub.T of the bipolar transistor, the low-temperature epitaxial technique has been adopted to form a thin epitaxial base layer thereof, as shown in FIG. 18. FIG. 19 shows the characteristics of the cut-off frequency f.sub.T and the maximum operating frequency f.sub.max (ordinate) with respect to the collector current I.sub.C (abscissa) of the bipolar transistor manufactured as described above. FIG. 19 indicates that although the maximum value of the cut-off frequency f.sub.T can be increased as high as 44.3 GHz and further the maximum operating frequency f.sub.max can be also improved as high as 25.1 GHz, the early voltage V.sub.A is as low as 25 V.
In order to realize high frequency analog circuits, however, it is required that the maximum operating frequency f.sub.max and the early voltage V.sub.A are both high.
In more detail, as understood by the dependency of power gain upon frequency in the analog circuit shown in FIG. 20, for instance, the maximum operating frequency f.sub.max of the high frequency analog circuit is determined as a frequency at which the power gain (referred to as power amplification factor) becomes 1! or 0 dB!. Further, in the field of the analog circuits, the highest gain is required for amplifiers. However, when the power gain exceeds 20 dB greatly, since the probability of parasitic oscillation increases, the power gain is set to about 20 dB in general. Therefore, as understood by the graphical representation shown in FIG. 20, the operating frequency of the analog circuit is usually set to about 1/10 of the maximum operating frequency f.sub.max. In other words, when the operating frequency of the analog circuits is decided on the basis of the design specifications, about ten times of the operating frequency is needed as the maximum operating frequency f.sub.max thereof.
On the other hand, the relationship between the early voltage V.sub.A and the supply voltage V.sub.CC is as follows:
Although various current source circuits are used for the bipolar ICs, the basic current source circuit results in a circuit as shown in FIG. 21, in which I.sub.ref to I.sub.C0 is a reference current. In FIG. 21, a current I.sub.C1 the same as the reference current I.sub.C0 is supplied through a circuit of a transistor Q.sub.1, whose structure is the same as a transistor Q.sub.0. In the same way, a current I.sub.Cn n-times larger than the reference current I.sub.C0 is supplied through a circuit in which n-units of transistors (each structure is the same as the transistor Q.sub.0) are connected in parallel to each other.
Here, the bipolar transistor is provided with an early effect, so that the collector current I.sub.C can be expressed as EQU I.sub.C =I.sub.S .multidot.(1+V.sub.CE /V.sub.A).multidot.exp(V.sub.BE /V.sub.T)
where I.sub.S denotes a constant indicative of the transfer characteristics in the forward active region of the transistor; V.sub.CE denotes the collector-emitter voltage of the transistor; and V.sub.BE denotes the base-emitter voltage of the transistor. Further, V.sub.T can be expressed as V.sub.T =k. T/q where k denotes a Boltzmann's constant, T denotes the absolute temperature of the transistor and q denotes the charge elementary quantity.
Consequently, the currents I.sub.Cn and I.sub.C0 flowing through the transistors Q.sub.n and Q.sub.0, respectively can be expressed as EQU I.sub.Cn =n.multidot.I.sub.S .multidot.(1+V.sub.CEn /V.sub.A).multidot.exp(V.sub.BE /V.sub.T) EQU I.sub.CO =I.sub.S .multidot.(1+V.sub.CEO /V.sub.A).multidot.exp(V.sub.BE /V.sub.T)
Therefore, the ratio of I.sub.Cn /I.sub.C0 is not an ideal value of n times but as EQU I.sub.Cn /I.sub.Co =n(1+V.sub.CEn /V.sub.A)/(1+V.sub.CE0 /V.sub.A)
By the way, when considering the degree at which the above-mentioned non-ideal state can be allowed, it is necessary to avoid at least such a state that (n+1)-time current flows when n-units of the transistors are connected in parallel. This is because it is impossible to control the transistor currents on the basis of the number of the transistors. On the other hand, since the number n of the transistors for constructing an ideal circuit is about n=20, it will be preferable to satisfy the following conditions: EQU 20.multidot.(1+V.sub.CEn /V.sub.A)/(1+V.sub.CE0 /V.sub.A).ltoreq.21
or EQU (1+V.sub.CEn /V.sub.A)/(1+V.sub.CE0 /V.sub.A).ltoreq.1.05
Here, since the collector-base voltage V.sub.BC is zero, V.sub.CE0 =V.sub.BE to 1, and further since V.sub.CEn is roughly the same as the supply voltage V.sub.CC, the above-mentioned conditional expression can be expressed as EQU (1+V.sub.CC /V.sub.A)/(1+1/V.sub.A).ltoreq.1.05
Therefore, the following expression can be obtained: EQU V.sub.A .gtoreq.20.multidot.V.sub.CC -21
As a result, when the supply voltage V.sub.CC is 3V, the early voltage V.sub.A as high as 39 V is required. In the conventional transistors, however, even if the thickness of the base layer is reduced with the use of the low-temperature epitaxial technique, since the early voltage V.sub.A is as low as 25 V, there exists a problem in that it is impossible to obtain a necessary early voltage V.sub.A.

Semiconductor device having bipolar transistor with unique ratio of base gummel number to impurity concentration of collector region


A heterojunction field effect transistor having an InP substrate, comprising a buffer layer formed between an active layer where a carrier travels and said InP substrate, wherein said buffer layer has at least two cycles of superlattices, each of said superlattices being formed of at least one semiconductor selected from the group consisting of Al.sub.x In.sub.1-x P (0.1.ltoreq.x.ltoreq.1), Ga.sub.x In.sub.1-x P (0.ltoreq.x.ltoreq.1), Al.sub.x Ga.sub.1-x As (0.ltoreq.x.ltoreq.1), and Al.sub.x In.sub.1-x As (0.5.ltoreq.x.ltoreq.1), and at least one semiconductor selected from the group consisting of InP and In.sub.0.52 Al.sub.0.48 As.

1. Field of the Invention
The present invention relates to a heterojunction field effect transistor having an InP substrate.
2. Description of the Prior Art
Conventionally, in a heterojunction field effect transistor having an InP substrate, a structure is disclosed in, e.g., Japanese Unexamined Patent Publication No. 63-278277 issued on Nov. 15, 1988, which uses an InAlAs/InGaAs superlattice as the buffer layer, in order to prevent two-dimensional electron gas generation at an interface between a buffer layer and an active layer which occurs when only an InAlAs layer lattice-matched with an InP substrate is used as the buffer layer, and to prevent two-dimensional electron gas generation in an InGaAs layer in a superlattice which occurs when an InAlAs/InAlGaAs superlattice lattice-matched with an InP substrate is used as the buffer layer.
FIG. 1A shows the sectional structure of a field effect transistor disclosed in this official gazette, and FIG. 1B shows an energy band diagram indicating a change in conduction band of the field effect transistor.
Referring to FIG. 1A, reference numeral 611 denotes an InP substrate; 612, an InAlAs/InAlGaAs superlattice; 613, an InGaAs active layer; 614, an n-InAlAs electron supply layer; 615, an n-InGaAs contact layer; 616, a source electrode; 617, a gate electrode; and 618, a drain electrode.
In the structure shown in FIG. 1A, when compared to a structure using only an InAlAs layer which is lattice-matched with an InP substrate as the buffer layer, an impurity serving as a heavy donor is trapped in the heterointerface of the InAlAs/InAlGaAs superlattice 612 lattice-matched with the InP substrate 611. Thus, two-dimensional electron gas generation at the interface between the InGaAs active layer 613 and the InAlAs/InAlGaAs superlattice 612 serving as the buffer layer is suppressed.
When compared to a structure using an InAlAs/InGaAs superlattice lattice-matched with an InP substrate as the buffer layer, the InAlGaAs layer has a larger band gap than the InGaAs layer. Thus, two-dimensional electron gas generation in the InAlGaAs layer in the superlattice is decreased.
In the above conventional structure, however, when the GaAs composition ratio of the InAlGaAs layer is less than 0.87, as a difference in composition is small between the AlInAs layer and the InAlGaAs layer, the effect of suppressing propagation of dislocations present in the InP substrate to the active layer, diffusion of an impurity, e.g., Fe, doped in increase the resistance of the InP substrate, and the like is small. Thus, the crystallinity of the active layer is degraded, leading to a low transconductance of the transistor.
The AlInAs layer is of an n type of about 1.times.10.sup.15 /cm.sup.3. In the conventional structure, when the GaAs composition ratio of the InAlGaAs layer is higher than 0.87 molar fraction, the band gap of the InAlGaAs layer becomes smaller than that of the InP substrate. If the film thickness of the AlInAs/InAlGaAs superlattice buffer layer is set to a value sufficient for eliminating propagation of the dislocations present in the InP substrate to the active layer, diffusion of the impurity, e.g., Fe, doped in increase the resistance of the InP substrate, and the like, electrons are generated in the AlInAs/InAlGaAs superlattice buffer layer. Then, an electron conduction path is formed in addition to the active layer, leading to a degradation in the pinch-off characteristics of the transistor.


In an example embodiment disclosed herein, Wide Area Network optimization modules coupled to peers are configured to maintain peer routing tables. The peer routing table (PRT) is used by the Wide Area Network optimization module to determine the peer for a given destination, such as an Internet Protocol “IP” destination. Each peer is responsible for advertising to other peers which networks the peer is able to reach. This information is advertised when a tunnel is first created and subsequently whenever necessary. Initially, a peer sends out a list of entries corresponding to its directly connected networks, with the exception of the network connected to the interface on which the peer is advertising (e.g. the network used for the tunnel). This enables other peers on the network to populate their PRT entries.

Proxies are often used at Transport layer and above as a performance enhancement mechanism, especially across WAN links. These proxies rely on peer-to-peer relationships in order to perform their function. This results in a proxy peer network overlaying the layer 3 network and having its own peer-routing information base. In order for the proxies to operate transparently without requiring elaborate configuration, the proxies should be able to derive their routing information from the underlying layer 3 (L3) network.
An approach to the problem is to use manual configuration, but that solution is definitely not attractive to an end user. Another approach is to try to derive the routing information from the L3 routing table of the attached router. The L3 routing table, however, does not have a view beyond the next hop and thus cannot automatically derive this information.

Wide area network optimization proxy routing protocol


Liquid to be injected from an injection nozzle is supplied through a liquid supply channel toward the injection nozzle. Negative pressure for sucking the liquid injected from the injection nozzle through a suction port is produced by a suction unit and guided through a suction channel toward the suction port. A bypass channel which bypasses the liquid supply channel on the upstream side with respect to the injection nozzle and connects with the suction channel is provided. The bypass channel is opened and closed by an opening and closing unit. According to this structure, flow of unnecessary liquid from the injection nozzle can be reduced by opening the opening and closing unit while injection of liquid is stopping.

1. Technical Field
The present invention relates to a technology of injecting liquid from an injection nozzle.
2. Related Art
A liquid injection device developed in recent years injects pressurized liquid such as water and physiological salt water through an injection nozzle toward living tissue to incise or excise the living tissue. When used in surgery, this type of liquid injection device can selectively incise or excise only the target tissue such as internal organs without damaging vascular structures such as blood vessels, and thus can reduce injuries of the surrounding tissue. Accordingly, this device is expected to decrease the burden imposed on a patient receiving the surgery.
According to the liquid injection device having this structure, however, the visibility of the surgery target area deteriorates due to accumulation of liquid injected from the injection nozzle or blood flowing from the living tissue as liquids remaining on the surgery target area. For overcoming this problem, such a liquid injection device which has a suction port disposed in the vicinity of the injection nozzle and connected with a suction pump has been proposed (JP-A-1-313047). According to this device, the liquid or blood remaining on the surgery target area is sucked and discharged through the suction port brought near the surgery target area, so that sufficient visibility of the surgery target area can be secured.
In addition, such a liquid injection device which injects liquid from an injection nozzle not continuously but in pulses produced by periodically varying the flow of injection has been proposed (JP-A-2008-82202). This liquid injection device has a supply pump which pressurizes and supplies liquid toward a liquid chamber connected with the injection nozzle, and an actuator which varies the volume of the liquid chamber. The liquid injection device thus constructed pressurizes liquid within the liquid chamber and injects the liquid in pulses from the injection nozzle by rapidly decreasing the volume of the liquid chamber filled with liquid. According to the device which injects liquid in pulses, injection of only a small amount of liquid is required for incising or excising living tissue. Thus, reduction of the quantity of the liquid remaining on the surgery target area can be achieved.
According to this type of liquid injection device, however, liquid continuously flows from the injection nozzle and accumulates on the surgery target area even during suspension of incision or excision of living tissue. More specifically, in the case of the liquid injection device capable of injecting liquid in pulses, the supply pump keeps operating to maintain a sufficient pressure of liquid to be supplied to the liquid chamber even while the operation of the actuator is stopping (injection of pulsed liquid is stopping). In this case, liquid pressurized and supplied from the supply pump continuously flows from the injection nozzle. Even when the operation of the supply pump is stopped, the liquid keeps flowing from the injection nozzle until the time when the pressure of the liquid pressurized and supplied toward the liquid chamber sufficiently drops, which pressure drop cannot be produced immediately after the stop of the supply pump. Thus, the liquid remaining on the surgery target area as liquid not used for incision or excision of the living tissue (that is, unnecessary liquid) is required to be sucked and removed, which increases labor for the user.

Liquid injection device and surgical instrument including liquid injection device


A composition curable by a metathesis reaction upon mixing its components and comprising an olefin-containing substrate, a metathesis catalyst, and a reaction control agent for slowing the progress of the metathesis reaction. The metathesis catalyst is a ruthenium or osmium carbene complex catalyst having high activity and good air stability. In one embodiment, the catalyst is free of phosphine ligands. The reaction control agent is an organic compound that contains carbon-carbon double and/or triple bonds and one or more Group 14 atoms and is present in an amount effective to slow the progress of the metathesis reaction. In one embodiment, the olefin-containing substrate may comprise one or more oligomers or polymers having a >20 wt. % linear siloxane (Si—O—Si) backbone tethered and/or end-capped with functional olefin groups, such as cycloalkenyl group.

Addition polymerizable silicone resins are widely used in many fields such as electronics, health care and automotive applications. The polymerizable resins are cured as a two-part system using a hydrosilation reaction. A platinum catalyst is used in one part, the catalyst side, and a hydrogen terminated polydimethylsiloxane (HPDMS) in the other part, the base side, while both sides contain vinyl terminated polydimethylsiloxanes (PVDMS) resins. When these materials are cured at room temperature, they are referred to as room temperature vulcanized (RTV). The most common RTV materials are typically offered as a 10:1 ratio base/catalyst, such as RTV630 (GE Silicones), while some other RTV materials are offered at a 1:1 ratio, such as RTV6428 (GE Silicones). Various working times are required depending on the application from 2 minutes to several hours and may involve a heat curing step above ambient temperature. The working time is controlled with a retarder or inhibitor mixed with the catalyst component, such as an amine or acetylenic compound.
Another class of addition polymerizable silicone resins is the liquid silicone rubber (LSR) materials prepared through the liquid injection molding (LIM) process. The LSR materials are cured at a temperature of 120° C.-180° C. in a mold injected to after mixing. The mixture includes a retarder mixed with the catalyst component, such as an amine or acetylenic compound, which allows the hydrosilation reaction to occur at the mold temperature only.
Both the RTV and LSR types of formulations suffer from the shortcomings of the hydrosilation mechanism. These shortcomings include: (1) deactivation of the platinum catalyst by sulfur or other nucleophilic impurities; (2) high shrinkage, approximately 1%, due to the high reduction of free volume upon polymerization; (3) high cost of platinum metal needed for catalysis; (4) high cost of HPDMS and PVDMS resins; (5) requirement of two different resins to be employed, namely vinyl and hydrogen terminated; (6) undesirable hydrogen evolution from the decomposition of the hydrosiloxane cross-linkers that typically are present in these systems; and (7) vinyl functionalized PDMS resins have a low hydrocarbon content in the main chain after polymerization due to the presence of only an ethyl spacer, which may lead to a relatively high dielectric constant, which is an undesirable property for some electronic applications.
A new type of polymerization system has been recently developed that may potentially be used to replace addition-curable silicones and platinum catalysts in a wide variety of applications to thereby avoid the shortcomings of the hydrosilation mechanism discussed above. In this new metathesis reaction system, curing is achieved by a ring-opening metathesis polymerization (ROMP) mechanism. Metathesis is generally understood to mean the metal catalyzed redistribution of carbon-carbon double bonds. The polymerizable composition comprises a resin system that includes functionalities or groups that are curable by ROMP together with a metathesis catalyst, such as a ruthenium carbene complex. However, to efficiently utilize ROMP to prepare polymers, there is a need to control the progress of polymerization, particularly for molding applications.
In commonly-owned U.S. Pat. No. 6,649,146, a two-part room temperature ROMP-curable formulation containing siloxane polymers and fillers was described as usable as a dental impression material. The catalysts described therein are ruthenium carbene complexes containing phosphine ligands. These catalysts, however, are air sensitive because the phosphines can dissociate and oxidize, thereby leading to reduced shelf life. An alternative highly active ruthenium carbene complex that does not contain phosphine groups is described in Hoveyda et al. U.S. Pat. No. 6,921,735. This alternative catalyst has a good air stability profile. However, when this alternative catalyst is substituted for the catalysts containing the phosphine ligands, the composition exhibits a very short working time after mixing, on the order of 20 seconds, which makes the use of these compositions impractical in many applications, such as dental impression materials. There is thus a need to provide a room temperature ROMP-curable formulation that has good air stability as well as a longer working time after mixing.
In addition to ROMP, other metathesis reaction systems utilize metathesis catalysts, for example ring closing metathesis, acyclic diene metathesis polymerization, ring opening metathesis and cross metathesis. There is further a need for controlling the progress of reaction in these other metathesis reaction systems.

This patent is subject to a terminal disclaimer.

Metathesis-curable composition with a reaction control agent


An acquisition device includes a wall and a transducer constituted by a body on which electrodes are fastened spaced apart from one another. An electrical impedance of the transducer is variable as a function of deformation of the transducer. When looking in a direction perpendicular to a surface of the wall, at least two electrodes of the plurality of electrodes are spaced apart from each other. The transducer is incorporated under the surface of the wall.

Numerous deformation or force sensors have been developed for applications of weighing stationary or moving vehicles on a roadway, and for tracking the state of the roadway.
In some such sensors, the transducer is formed by a body that has electrodes fastened thereon, and that is made of a material such that when a pair of electrodes are fastened on the material, the resistance between the electrodes varies as a function of the deformation suffered by the material (i.e. a piezoresistive material).
The specific nature of such sensors is that the electrodes are fastened on opposite sides of said body on faces of the body that are normal, i.e. perpendicular, to the direction in which the force for measuring is applied.
When the force is applied to the transducer, the body deforms in this direction; consequently, the resistance measured between the electrodes on the faces that are normal to the applied force varies; this variation of resistance is detected and/or measured by the sensor in order to provide the looked-for information.
Such transducers may be made for example in the form of "intelligent concretes" or "intelligent bituminous mixes", i.e. concretes or bituminous mixes that are filled with nano-particles and that present piezoresistive behavior. They can also be made by means of piezoresistive polymers.
There also exist transducers that are made in the form of piezoresistive tapes, in particular based on polymers, ceramics, and piezoresistive crystal materials.
Nevertheless, those various transducers are not entirely satisfactory since each of them raises the following problems at least in part:                the long duration required for putting transducers into place and thus the long time the roadway is made unavailable;        the lack of reliability of such transducers in the medium to long term, due to incompatibilities between the materials of the transducers and filler materials with the material of the roadway, the transducers being subjected to stresses that are very large and repeated;        the damage caused to the roadway by using transducers, given that they have height that is not negligible, thereby reducing the lifetime of the roadway in the vicinity of the sensors;        the poor accuracy of the transducers, which is affected by the speeds of the vehicles and the paths they follow, and by variations in temperature and in moisture; and        finally, large costs due both to the price of the transducers and to the cost of putting them into place in the roadway.

Sensor with a plurality of acquisition devices that measure force using impedance

INSTITUT FRANCAIS DES SCIENCES ET TECHNOLOGIES DES TRANSPORT, DE L'AMENAGEMENT ET DES RESEAUX

CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS


Systems and methods for setting parameters for transmissions of data from a mobile station to a base station in a wireless communications system. One embodiment comprises a method including a network detecting a mobile station entering or leaving soft handoff and responsively modifying a transmission parameter. The transmission parameter may comprise frame duration, wherein if the mobile station enters soft handoff, the frame duration is set to a larger value and if the mobile station leaves soft handoff, the frame duration is set to a smaller value. The network may determine whether the mobile station should enter or leave soft handoff based upon PSMMs and may send handoff direction messages (HDMs) to the mobile station, thereby causing the mobile station to enter or leave soft handoff and to set the transmission parameter accordingly.

1. Field of the Invention
The invention relates generally to the field of telecommunications, and more particularly to mechanisms for controlling data transmission parameters for wireless communications channels based upon prevailing transmission characteristics of the channels.
2. Related Art
Wireless communication technologies are rapidly advancing, and wireless communication systems are utilized to provide a larger and larger portion of the communications capacity that is currently available to users. This is true despite the additional technological impediments that are faced in implementing a wireless communication system, as compared to a wireline system. For instance, wireless communication systems must deal with issues relating to power control between a base station and its mobile stations in order to maximize the performance of the system, whereas a wireline system does not.
One type of wireless communication system comprises a cellular CDMA (code division multiple access) system which is configured to support voice and data communications. This system may have multiple base stations which communicate via wireless channels with multiple mobile stations. (The base stations are also typically coupled via wireline networks to various other systems, such as a public switched telephone network.) Each base station communicates with a set of mobile stations that are within a sector corresponding to the base station.
It is typically a goal of a wireless communication system to optimize the performance of the system by maximizing the data throughput of the system. This data throughput may include contributions from each of the mobile stations with which the base station communicates. Because the base station typically communicates with multiple mobile stations, the system cannot simply allow communications between the base station and one of the mobile stations to be optimized at the expense of communications with the other mobile stations. On the other hand, the system cannot allow communications with all of the mobile stations to use the highest power levels, data rates and other transmission parameters that are physically possible because they would likely generate so much interference that little, if any, of the data would actually be successfully transmitted. It is therefore necessary for the system to implement controls on the communications with the different mobile stations in order to provide an acceptable level of service to each of them.
A complicating factor in the control of the communications between a base station and various mobile stations is that the mobile stations may be in communication with more than one base station. While a mobile station which is located in close proximity to a first base station generates interference that primarily affects the mobile stations in the same sector, mobile stations that are farther from the base station may generate interference that significantly affects mobile stations in other sectors. While a single base station can handle the first situation relatively easily, it has no knowledge of mobile stations in other sectors, and may therefore require complicated backhaul signaling to handle the second situation. It would therefore be desirable to provide a means to handle the second situation which increases system performance in relation to all of the base stations and corresponding sectors.

Systems and methods for using selectable frame durations in a wireless communication system


A method and apparatus for connecting anchor sheets to each other and/or to a floor. The approach includes using attachment pieces which fit into an area of reduced thickness of the anchor sheet which surround a cut away of the anchor sheet. In one embodiment, the attachment pieces are corner pieces which overlap areas of reduced thickness on a number of anchor sheets.

The earlier cases by the same inventor Pacione disclose an anchor sheet which can be supplied as a small or large module, with or without a pre-attached decorative covering. These earlier cases also disclose the anchor sheet as a modular unit which can form a contiguous mass of anchor sheet. Such a contiguous mass can be formed by attaching the anchor sheets together by some form of overlap or by abutting the anchor sheets to each other and using an overlap of decorative covering or tape. Such mass can be free floating or attached to the floor


A new and distinct Olea europaea L. olive tree variety named ‘ASKAL’, particularly characterized by a medium-sized tree with vigorous growth, high fruit yield, field resistance to Spilocaea oleagina, mature fruit with average commercial oil content of 23.5% on fresh weight basis under irrigation, a well-balanced fruity-grassy taste, good stability (7.8 h at 1100C), high oleic acid content of about 72% and good polyphenol content (233 mg/kg).

The present invention relates to a new and distinct variety of an olive tree, botanically described as Olea europaea L. of the Oleaceae family, and hereinafter referred to by the variety denomination 'ASKAL'.
The new Olea europaea 'ASKAL' is a product of a planned breeding program conducted by the inventors, Shimon Lavee, Benjamin Avidan and Yair Manni, in Bet Dagan, Israel. The objective of the breeding program was to develop a new Olea europaea L. variety with a vigorous growth, high fruit yield, resistance to Spilocaea oleagina (peacock eye leaf disease), mature fruit with good eating quality and oil production.
The new Olea europaea L. 'ASKAL' originated from a cross made by the inventors in 1990 in Bet Dagan, Israel. The female or seed parent is the Olea europaea L. 'BARNEA' (unpatented), and the male or pollen parent is the Olea europaea variety 'MANZANILLO' (unpatented). The new Olea europaea L. 'ASKAL' was observed and selected from the progeny of the stated cross in 1994 by the inventors in a controlled environment in Bet Dagan, Israel.
Asexual propagation of the new Olea variety by rooting of vegetable cuttings was first performed in the spring of 1995 in Bet Dagan, Israel, and has demonstrated that the combination of characteristics as herein disclosed for the new variety are firmly fixed and retained through successive generations of asexual propagation. The new variety propagates true to type.

State of Israel, Ministry of Agriculture & Rural Development, Agricultural Research Organization


A reagent container assembly adapted for being installed in a cavity of an analyzer. The reagent container assembly comprises a housing having an upper opening and defining at least one circular array of chambers, each chamber being adapted for receiving a reagent container, a cover for closing the upper opening of the housing, and a locking mechanism arranged within the housing. The locking mechanism is adapted for locking the cover and for preventing rotation thereof. The locking mechanism is further adapted for locking the housing and thereby preventing rotation thereof when the reagent container assembly is removed from its position in the analyzer. The locking mechanism is further adapted for cooperating with a pin arranged at the bottom of the cavity of the analyzer when the reagent container assembly is installed in the analyzer, the housing being unlocked by the cooperation and thereby allowed to be rotated within the cavity of the analyzer.

In automatic analyzers, and in particular in clinical chemistry analyzers, it is convenient to have a reagent container assembly which contains a plurality of reagent containers suitable for carrying out various analysis and which can be easily handled and installed in the analyzer.
For proper and reliable operation of the analyzer it is indispensable to avoid using the wrong reagent when performing an analysis. It is therefore important to make sure that the proper reagents are loaded into the reagent container assembly installed in the analyzer and that the reagent management system of the analyzer has information that identifies those reagents. For this purpose, the individual reagent containers as well as the reagent container assemblies are identified e.g. by means of barcode labels for the purpose of automatic identification and control by the reagent management system of the analyzer.
In spite of the above actions and steps for ensuring proper identification and control of the reagents being used, it cannot be fully excluded that reagent containers installed in the analyzer are manually taken out and replaced by another reagent and that the reagent management system of the analyzer may fail to detect errors that may occur during such manipulations.
The problematic situation just mentioned is particularly prone to occur when the reagent container assemblies are manually handled for installing them into the analyzer and removing them from the analyzer when necessary. In larger analyzer systems, the risk of errors in handling reagents can be considerably reduced by an expensive, fully automatic handling of the regents. Such an approach is however not possible in case of a low cost, relatively small analyzer intended to be used in small laboratories or even by medical doctors in their own laboratories, because in those cases, in order to reduce the manufacturing costs of the analyzer, manual handling of the reagent assemblies is indicated. Nevertheless, also in those cases, it is desirable to reduce the risk of errors in handling the reagents as far as possible.

Reagent container assembly and analyzer comprising such assembly


A multi-leaf collimator for use in a radiotherapeutic apparatus comprises a plurality of elongate narrow leaves arranged side-by side and supported in a frame, the frame having upper and lower formations for guiding each leaf into which extend ridges on the upper and lower edges of the leaves, thereby to allow the leaves to move in a longitudinal direction, the upper and lower formations being aligned so that the sides of the leaves when fitted are at a non-zero angle to the beam direction, the upper and lower ridges being located on the upper and lower edges of the leaves so that a line joining their centres is at a non-zero angle to the sides of the leaf, tilted relative to the sides in a sense opposite to that of the beam. An outer face of the upper and/or lower ridges can be aligned with a side face of the leaf, for ease of manufacture. A radiotherapeutic apparatus is also disclosed, comprising a source of radiation and a multi-leaf collimator for shaping the radiation emitted by the source, the multi-leaf collimator being as set out above.

External Beam Radiotherapy involves the production of a beam of ionising radiation, usually x-rays or a beam of electrons or other sub-atomic particles, which is then directed towards a cancerous region of the patient. This adversely affects the tumour cells, causing an alleviation of the patient's symptoms. Generally, it is preferred to delimit the radiation beam so that the dose is maximised in the tumour cells and minimised in healthy cells of the patient, as this improves the efficiency of treatment and reduces the side effects suffered by a patient. A variety of methods of doing so have evolved.
One principal component in delimiting the radiation dose is the so-called "multi-leaf collimator" (MLC). This is a collimator which consists of a large number of elongate thin leaves arranged side to side in an array. Each leaf is moveable longitudinally so that its tip can be extended into or withdrawn from the radiation field. The array of leaf tips can thus be positioned so as to define a variable edge to the collimator. All the leaves can be withdrawn to open the radiation field, or all the leaves can be extended so as to close it down. Alternatively, some leaves can be withdrawn and some extended so as to define any desired shape, within operational limits. A multi-leaf collimator usually consists of two banks of such arrays, each bank projecting into the radiation field from opposite sides of the collimator. An example of an MLC is shown in EP-A-0,314,214.
WO 2007/124248 shows an MLC with leaves having ridges along their upper and lower edges, to engage in corresponding formations in a leaf support structure. However, this document teaches that the leaves should be aligned relative to the radiation source, i.e. that the sides of the leaf are aligned with the local direction of the radiation.
WO 2007/003925 also shows an MLC leaf having ridges along its upper and lower edges, to engage in corresponding formations in a leaf support structure, but is silent as to the orientation of the leaf relative to the beam.
One factor in the design of a high-quality MLC is the leakage of radiation through the collimator. One likely area for leakage is between the leaves; there must obviously be some degree of separation between the leaves in order to allow them to slide easily relative to the adjacent leaf, and this small gap could allow for leakage. To alleviate this, MLC leaves and their supporting structures can be designed so that the leaves are held at a small acute angle to the beam direction. This means that from the point of view of the beam, the gap between adjacent leaves is closed.


A method for conducting Internet domain name service to users connected to the Internet comprises an automated procedure for transferring Internet domain name service from a domain name owner to a domain name manager. This method further comprises Internet sub-domain name services to prospective buyers based on domain names transferred to the domain name manager. Messages requesting domain name service, including requests from domain name owners to sub-license their particular domain name to prospective sub-domain name buyers and from prospective sub-domain name buyers to license available sub-domain names, are received and responded to by an automated domain name management system. This automated domain name management system further comprises an interactive website which includes a database, search engine, and Web server.

1. Field of the Invention
The present invention relates to a method for conducting internet domain name service. In particular, this invention pertains to an automated procedure for licensing sub-domain names via an Internet portal.
2. Description of Related Art
A domain name is a unique address that identifies a computer or network that is connected to the Internet. A particular domain name can be comprised of different domain name levels. Domain names begin with a top level domain name with each subsequent domain name level separated by a dot. Domain level hierarchy is such that top level (level one) domain names are those names located furthest to the right of the entire domain name. These level one domain names include descriptors such as 'com', 'org', 'net', or any other designation approved by the Internet Corporation for Assigned Names and Numbers (ICANN). Level two domain names are located to the immediate left of the top level domain name while level three domain names are to the immediate left of the level two domain names. Additional domain name levels sequentially follow, from right to left, according to this same scheme. For purposes of the discussion herein, domain names are referred to as only the combination of level one and level two domain names. Domain name levels greater than two will, meanwhile, be sequentially referred to as sub-domains from right to left. As an example, in the website "www.sub2.sub1.foo.com", the term "foo.com" is the domain name while terms "sub1", "sub2", and "www" are respectively sub-domains one, two, and three.
According to current domain name architecture and available sales methodology on the Internet, rights to use a single domain name are transferred only to a single entity, which entity then uses that domain name as well as all variants thereof. Legally, this entity has only a license to use the domain name; however, as long as the name is unrelated to someone else's trademark or legal right to use the name, this license awards full administrative sovereignty over the domain name. This entity thus becomes the administrative contact for the particular domain name. As the administrative contact, this entity can speak on behalf of the organization for which the domain name is registered and should be able to answer non-technical questions about the organization's plans for the name and procedures for establishing sub-domains. Also, the administrative contact should be able to represent the organization regarding use of the name. The licensee is commonly referred to in the art as the "owner" of the domain, although an actual ownership interest is not created. For convenience, the licensee will be referred to herein as the "owner" to be consistent with general nomenclature in the art.
Current domain name vendors do not license rights to sub-domain names. This limitation prevents full exploitation of the value of domain names, as many good names, such as "rover.ismydog.com", are not available for transfer. A further complication limiting the creation of sub-domain/domain name combinations is the current domain naming and resolution architecture. Once a right to use a domain name is transferred, the licensee of that name controls domain name service for all sub-domains related to that domain name.
Registrars for domain names provide a name service for all level two domains emanating off of a level one domain. In order for sub-domains (domain names of level three or greater) to be licensed in a manner similar to domains, the provider of name service for the domain name must be able to provide individual name service for all sub-domains of the domain. However, this is not practical unless the registrar is able to provide name service for a critical mass of domain names. It would therefore be advantageous to permit the automated aggregation of name service for numerous domain names.

Method and apparatus for conducting domain name service


A computing system for managing a contact center having agent instances includes processor(s) in a management network serving an end-user network that includes the contact center and a communication distributor server operable to receive communications from customers to the end-user network and assign one or more of the agent instances to service the communications from the customers. The processor(s) are configured to perform tasks including (a) receiving, from the end-user network, data associated with processes of the server(s) including the communication distributor server, (b) determining, based on a specification, operations to be performed by the one or more servers, and (c) providing, to the one or more servers, the operations, wherein the operations include changing a state of a particular agent instance of the agent instances or modifying an assigned schedule or assigned queue for the particular agent instance. A method and article of manufacture are also provided.

Many enterprises offering products and/or services to customers have both front-office functions and back-office functions. Front-office functions are customer-facing, while back-office functions generally support front-office functions. Many such enterprises utilize third-party software solutions to help manage agents in the front office and back office. Such software solutions may relate to customer communications, agent scheduling, and others. Additionally, many enterprises also utilize a third-party management network to help manage customer communications, agent scheduling, and other agent-related items by interfacing with the third-party software solutions and/or with agent instances. Such a third-party management network may allow a particular enterprise to define rules with associated triggers, conditions, and actions.

Live-monitoring of agent instances in a contact center network


Techniques are described for unified identity and access management (IAM) across multiple applications in a distributed (e.g., cloud) computing environment. Implementations provide for IAM across multiple applications through use of a single, unified IAM tool including an IAM interface. The IAM tool can manage user identity and user access rights for multiple applications in the platform environment. The IAM tool can also employ a unified IAM database, which stores user profiles that each describes user access rights for a user in one or more applications. Through use of the unified IAM tool, an operator can access a single interface to manage user identity and access privileges across multiple applications which may have their own identity management interfaces, with user roles in different applications mapped through use of an equivalency matrix in some cases. The IAM tool can be used to add, remove, or edit user access privileges for multiple applications.

In a cloud computing environment or other type of distributed computing environment, multiple applications may be hosted and made available to users such as subscribers to the environment. Users can access executing instance(s) of application(s) in the environment, and thus avoid the resource expenditure and/or monetary expense that would be consumed if the user purchased and executed the application(s) in their own computing environment. In a traditional environment in which multiple applications (e.g., from various application providers) are hosted, identity management can pose a challenge given that the number of identity management tasks to be performed can increase rapidly in proportion to the number of applications hosted in the environment.

Cross-application identity and access management


In a communication system in which a plurality of communication apparatuses form a wireless network and communicate with each other, a communication apparatus establishes timing synchronization by transmitting and receiving a beacon to and from other communication apparatuses. The communication apparatus determines whether or not beacon slots for transmitting the beacon are occupied, and if the beacon slots are occupied, connects to another communication apparatus without transmitting the beacon.

1. Field of the Invention
The present invention relates to a communication technique in a communication system.
2. Description of the Related Art
In the WUSB 1.0 standard, a host and devices form a WUSB cluster and communicate using TDMA-based superframes (for example, see Wireless Universal Serial Bus Specification, Revision 1.0). WUSB is an abbreviation for Wireless Universal Serial Bus, and TDMA is an abbreviation for Time Division Multiple Access.
A superframe consists of 256 Media Access Slots (MASs) of 256 μs each, with the first 16 MASs being used as a BP (Beacon Period) to transmit beacons. Three beacon slots are assigned to one MAS and therefore 48 beacon slots exist in the 16 MASs, while beacon slot number 0 and number 1 cannot be used for band reservation because they are used for BP relocation.
The remaining duration of the superframe other than the BP is used as DRPs (Distributed Reservation Periods), each of which is a band in which communication is possible within a cluster. The duration of a DRP is indicated by a DRP IE (DRP Information Element) in a beacon transmitted from the host or a device.
The number of a beacon slot for transmitting a beacon is determined by negotiation among the devices. A device also uses a BPO IE (Beacon Period Occupancy IE) in the beacon in order to communicate the numbers of the beacon slots used by neighboring devices from the device to devices existing as hidden terminals.
Synchronization among the hosts and devices is managed in an autonomous-decentralized manner, and the hosts have a function of managing superframe synchronization adjustment. A host or a device performs the superframe synchronization adjustment by receiving beacons of other devices.
The devices are broadly divided into: SBDs having a function of managing the superframe synchronization adjustment by themselves; DBDs not having the function of managing the superframe synchronization adjustment by themselves; and NBDs not managing the synchronization and not transmitting or receiving beacons for further reduction in power consumption. SBD is an abbreviation for Self-Beaconing Device, DBD for Directed Beaconing Device, and NBD for Non Beaconing Device.
Now, the frame structure at the MAC (Media Access Control) layer used by the WUSB 1.0 standard will be described with reference to FIG. 1.
This standard uses the ECMA-368 standard for the MAC layer. The communication time is managed based on a frame called a superframe 300, and one superframe has a duration of 65536 μs (for example, see Standard ECMA-368 High Rate Ultra Wideband PHY and MAC Standard). The first 16 MASs in the superframe are dedicated as a BP 400, and WUSB hosts and SBDs transmit a beacon in the BP 400 to reserve a band in the superframe as a DRP. The start point of the superframe, that is, the start point of the BP 400, is called a BPST (Beacon Period Start Time). A beacon 410 consists of a beacon group parameter 4110, a DRP IE 4120, a BPO IE 4130, and other IEs (Information Elements) 4140.
A device transmitting a beacon announces in the DRP IE 4120 the position of MASs of reserved bands, and announces in the BPO IE 4130 the beacon slot used by the device, the beacon slot numbers of neighboring devices, and the BP length.
Now, the relationship between a WUSB channel and the MAC layer will be described with reference to FIG. 2. Each DRP (420, 430, 440, 450, 460, 470) in FIG. 2 is a reserved period of a communication band in a certain WUSB cluster. In each DRP, a WUSB host broadcasts MMCs (Micro-scheduled Management Commands) that control the data input/output direction and so on. An MMC consists of a header and IEs.
The section from an MMC to the next MMC is called a TG (Transaction Group); for example, the TG for an MMC 443 is a TG 444. Described in the MMC 443 are the communication band in the direction from the WUSB host to the WUSB devices, the communication band in the direction from the WUSB devices to the WUSB host, and so on.
If a WUSB host has an SBD in the WUSB cluster, the management of the superframe synchronization adjustment with a neighboring device is performed by analyzing a packet that can be received around the SBD via the SBD and by moving the position of the BPST.
During the BP period, the SBD not only transmits a beacon by itself but also receives beacons from other devices in other beacon slots and analyzes which beacon slots are available by referring to the BPO IE.
However, there has been the following problem; if the BP reaches the maximum length and the beacon slots that the BP can accommodate are occupied, the SBD cannot transmit a beacon at startup and cannot connect to the WUSB host.

Communication apparatus for connecting to another apparatus in accordance with occupancy of beacon slots and communication method for the same


Antenna elements (1) to (4) are arranged at both ends in a diamond shape, and are located opposite to each other, while a length (a) of one edge of this diamond shape is set to a xc2xd wavelength (xcex/2). Antenna elements (5) to (12) are arranged in such a way that three portions are bent and the bent antenna elements are located opposite to each other, while a length (b) of one edge thereof is set to a xc2xc wavelength (xcex/4). One ends of the antenna elements (5) to (8) are connected to the antenna elements (1) to (4), whereas the other ends thereof are connected to the antenna elements (9) to (12). The antenna elements (9) and (10), and the antenna elements (11) and (12) are connected to each other at a power supply unit (13). With employment of such a structure, an antenna having a higher gain can be realized with having a simple plane structure.

The present invention is related to an antenna apparatus, and a radio apparatus and a radio relaying apparatus using this antenna apparatus in a mobile communication system mainly known as the PHS (Personal Handyphone System) system.
Conventionally, in an outdoor type small-sized base station apparatus (master unit) conducted in a mobile communication system such as the PHS system, while an omunidirectional antenna such as a sleeve antenna is used, the antenna gain of this omunidirectional antenna is lower than or equal to about 2 dBi. Also, in a fixed terminal apparatus used in a local wireless network (wireless local loop: WLL) which utilizes a mobile communication system such as the PHS system, an antenna gain requires approximately 10 dBi.
Very recently, in the above-described mobile communication system, high gains are required for antennas so as to extend communication covering areas. These antennas are used in indoor type compact base station apparatuses (mother units) and fixed terminal apparatuses.
As frequencies of the above-explained mobile communication system, 1,900 MHz band and 800 MHz band are mainly used. As antennas having high gains operable in these frequency bands, multi-staged co-linear array antennas are known from, for instance, Japanese Patent Publications Hei-5-267932, Hei-9-232851, and Hei-8-139521. This sort of antenna is to secure such a high gain by that while antennas having omnidirectional directivity characteristics within horizontal planes are arranged in the multi-stage manner along the vertical direction, the directivity characteristics within the vertical planes are narrowed by vertical polarized waves.
Also, for instance, as disclosed in Japanese Patent Publications Hei-5-259733 and Hei-8-204433, end-fire array antennas are known, namely typically known as a YAGI antenna and a dipole antenna equipped with a reflection plate. This sort of antenna is to secure a high gain by that non-powered elements are arranged along a direction parallel to a major radiation direction.
Furthermore, for example, as disclosed in Japanese Patent Publication Hei-6-334434, a broad-side array antenna is known, namely typically known as a patch array antenna. This sort of antenna is to secure a high gain by that while a plurality of antennas are arranged within a plane located perpendicular to a major radiation direction, these plural antennas are energized by the distribution manner.
Also, for instance, as described in Japanese Patent Publication Hei-6-268432 and also Japanese Utility Model Publication Hei-6-44219, a slim type antenna is known, namely typically known as a loop antenna equipped with a reflection plate and a slot antenna.
Then, as a broad-side array antenna mainly utilized in the VHF frequency range, for instance, xe2x80x9cANTENNA HANDBOOKxe2x80x9d issued by xe2x80x9cCQ Publishing Co.xe2x80x9d, on page 366, discloses such an antenna that two 1-wavelength antennas are arranged in either a regular square or a circle. Then, it is known in the field that a diamond-shaped antenna to which this broad-side array antenna has been applied can obtain a gain of approximately 6 dBi in the 1,900 MHz band and the 800 MHz band, and further, this diamond-shaped antenna having a compact/simple structure can obtain a gain of approximately 10 dBi in combination with a reflection plate.
Also, such an antenna is known in the field, in which plural sets of the above-described diamond-shaped antennas are arranged in a parallel connection manner or a series connection manner. FIG. 3 is a diagram for representing the conventional antenna apparatus structure and the current distribution thereof, in which 6 sets of diamond-shaped antennas are connected to each other in the parallel manner. This antenna apparatus is so arranged that 6 pieces of the diamond-shaped antennas 14 to 19 are connected in the parallel manner, and the power supply unit 20 is connected to the center portion. While the length xe2x80x9caxe2x80x9d of one edge of the diamond shape is set to a xc2xd wavelength (xcex/2), these diamond-shaped antennas 14 to 19 are operated as the broad-side array antenna constituted by 4 sets of half wavelength antennas so as to radiate the vertical polarized waves along the X direction and the xe2x88x92X direction. For instance, in the case that the operation frequency of the antenna apparatus is set to 1,900 MHz, the length xe2x80x9caxe2x80x9d of one edge of the diamond shape becomes 79 mm. Also, the entire width of the antenna apparatus becomes 670 mm. In this case, in the antenna apparatus shown in FIG. 3, in particular, the current distribution of the diamond-shaped antennas 16 to 19 located near the center cannot be optimized by mutually coupling the respective diamond-shaped antennas. As a result, it is known in this field that the effect of the plural arrangement becomes relatively small, a single set of the diamond-shaped antenna owns the gain of approximately 11.5 dBi, and the gain of approximately 15.5 dBi is obtained by combining the diamond-shaped antenna with the reflection plate.
Also, for example, Japanese Patent Publications Hei-6-188623 and Hei-6-169216, and Japanese Utility Model Publication Hei-4-44713 describe such a dual-loop antenna that a plurality of 1-wavelength loop antennas are connected parallel to each other, or series to each other. FIG. 4 represents the conventionally known structure of dual-loop antenna. This dual-loop antenna is arranged in such a manner that two sets of the 1-wavelength loop antennas are connected parallel to each other via the xc2xd-wavelength transfer path, and the power supply unit is connected to the central portion. Both the 1-wavelength loop antenna 21 and the 1-wavelength loop antenna 22 are operated in such a way that the vertical polarized waves are radiated along the X direction and the xe2x88x92X direction. While the length of the transfer path 23 is set to a xc2xc wavelength and the length of the transfer path 24 is set to a xc2xc wavelength,both the 1-wavelength loop antenna 21 and the 1-wavelength loop antenna 22 are connected to each other, and the power supply unit 25 is connected to the center point thereof. Since the dual-loop antenna is arranged in this manner, two sets of the 1-wavelength loop antennas 21 and 22 can be excited under in-phase condition. It is known in the field that a single set of the 1-wavelength loop antenna owns the gain of approximately 8 dBi, and the two 1-wavelength loop antennas own the gain of approximately 12 dBi by being combined with the reflection plate.
On the other hand, as a radio relaying apparatus used in the above-explained mobile communication system, the following radio relaying apparatuses are known in the field. That is, for instance, Japanese Patent Publication Hei-8-8807 discloses such a radio relaying apparatus which employs the antenna commonly-using filter and a large number of narrow-band amplifiers. Japanese Patent Publication Hei-8-508377 discloses such a radio relaying apparatus which uses the amplifier and the switch operable in synchronism with the upstream time instant and the downstream time instant in the time division duplexing (TDD) system. Also, Japanese Patent Publication Hei-8-298485 describes such a radio relaying apparatus in which the two relaying systems constructed of the upstream/downstream relaying systems are provided in the time division duplexing system.
However, in order to secure the high gain in the above-explained conventional multi-stage co-linear array antenna, a large number of antennas must be arrayed in the multi-stage manner along the vertical direction. For example, in the case that the gain of 10 dB is obtained in the 1,900 MHz band, the antenna height of 1 meter would be required. As a result, there are problems in the antenna setting places and also the mechanical strengths of the antennas. Also, it is not proper manner to build such a high-height antenna in the radio apparatus.
Also, in order to secure the high gain in the above-described conventional end-fire array antenna, a large number of antennas must be arrayed in the multi-stage manner along the major radiation direction. As a result, there are such problems in the antenna setting places and also the mechanical strengths of the antennas. Also, since the end-fire array antenna owns such a specific antenna structure, this end-fire array antenna is difficult to be built in the radio apparatus in a proper manner.
Furthermore, in order to secure the high gain in the above-described conventional broad-side array antenna, a large number of antennas must be arrayed on the vertical plane with respect to the major radiation direction. As a result, there are such problems in the antenna setting places and also the mechanical strengths of the antennas, since the entire area of this broad-side array antenna is increased. Also, since the broad-side array antenna owns such a large antenna area, this broad-side array antenna is difficult to be built in the radio apparatus in a proper manner.
Also, the above-described conventional slim type antenna owns such a problem that the radiation directivity characteristic cannot be optimized as the desirable characteristic, although this antenna owns the slim structure.
Then, the tip open diamond-shaped antenna owns another problem that the gain higher than 10 dBi cannot be obtained, which utilizes such an antenna that the two 1-wavelength antennas are arrayed in either the square shape or the circular shape.
Also, in the antenna where a plurality of tip open diamond-shaped antennas shown in FIG. 3 are arrayed in either the parallel connection manner or the series connection manner, in particular, the current distribution of the antenna elements located near the center cannot be optimized, because of the mutual couplings among the adjoining 1-wavelength elements. As a consequence, there is such a problem that the gain improving effect caused by the plural antenna arrangement is lowered.
On the other hand, in the above-explained conventional radio relaying apparatus, the structure of the amplifier capable of obtaining the large relaying gain becomes complex and bulky. Therefore, there is such a problem that such a bulky amplifier cannot be properly installed in an indoor type compact relaying apparatus.
The present invention has been made to solve the above-described various problems belonging to the conventional antennas, and therefore, has an object to realize a high-gain antenna apparatus having a compact, slim, and simple antenna structure usable in mobile communication systems operable in both UHF-frequency range and semi-microwave frequency range. Also, the present invention has an object to realize an indoor type radio relaying apparatus having a compact/simple arrangement.
To solve the above-explained problems, an antenna apparatus, according to the present invention, is featured by that a first antenna and a second antenna are arranged on both end portions in such a manner that each of two 1-wavelength antenna elements is bent at a center portion thereof and the two bent 1-wavelength antenna elements are located opposite to each other so as to thereby form a diamond shape; one end of the first and second antennas is opened; and a connection unit is provided on the other end thereof; a third antenna in which a central half-wavelength portion of each of two 1-wavelength antenna elements is bent in a symmetrical manner with respect to a straight line intersected perpendicular to the antenna elements is arranged at a center portion, both ends of which are connected to the first and second antennas; and a commonly-used power supply unit is provided. Since such a structure is employed, the antenna apparatus having the high gain can be realized with the simple plane structure.
Also, an antenna apparatus, according to the present invention, is featured by comprising: a plurality of antennas formed in a diamond shape in such a manner that each of two 1-wavelength antenna elements is bent at a center thereof and the bent 1-wavelength antenna elements are located opposite to each other; a transfer path; and a reflection plate; wherein:
the plurality of antennas are arranged in such a manner that the plural antennas are separated from each other by keeping an interval defined by multiplying a half wavelength by an integer along a vertical direction with respect to the plane of the diamond shape, and major polarized wave directions thereof are made identical to each other; the plurality of antennas are connected to each other by the transfer path; a tip portion of an antenna system for connecting the plurality of antennas is opened and a power supply unit is provided at the other end thereof; and the reflection plate is arranged to be separated by a predetermined interval along the vertical direction with respect to the diamond-shaped plane of the plural antennas. Since such a structure is employed, the antenna apparatus having the high gain can be realized with the simple structure.
Also, a radio apparatus, according to the present invention, is featured by comprising: a printed board in which an antenna is constructed of a printed pattern; and a wireless circuit unit; wherein: both the printed board and the wireless circuit unit are fixed in a predetermined interval; and a housing of the wireless circuit unit is commonly used as a reflection member. Since such an arrangement is employed, the radio apparatus equipped with the antenna apparatus having the high gain can be realized with the simple arrangement.
Also, a radio relaying apparatus, according to the present invention, is featured by that a plurality of antenna apparatuses are arranged within the same housing in such a manner that major radiation directions of the plural antenna apparatuses are directed to different directions; and power supply units of the plural antenna apparatuses are electrically connected to each other. Since such an arrangement is employed, the radio relaying apparatus installed in the indoor place can be realized with the simple arrangement.
Further, a radio relaying apparatus, according to the present invention, is featured by that a plurality of antenna apparatus are arranged within different indoor spaces from each other; and the respective power supply units of the plural antenna apparatuses are connected to each other via a cable. Since such an arrangement is employed, the radio relaying apparatus installed in the indoor place can be realized with the simple arrangement.
Also, a radio relaying apparatus, according to the present invention, is featured by that a plurality of antenna apparatus are embedded within walls of different rooms from each other; and the respective power supply units of the plural antenna apparatuses are connected to each other via a cable. Since such an arrangement is employed, the radio relaying apparatus installed in the indoor place can be realized with the simple arrangement.
The invention as recited in claim 1 of the present invention is related to such an antenna apparatus wherein: a first antenna and a second antenna are arranged on both end portions in such a manner that each of two 1-wavelength antenna elements is bent at a center portion thereof and the two bent 1-wavelength antenna elements are located opposite to each other so as to thereby form a diamond shape; one end of the first and second antennas is opened; and a connection unit is provided on the other end thereof; a third antenna in which a central half-wavelength portion of each of two 1-wavelength antenna elements is bent in a symmetrical manner with respect to a straight line intersected perpendicular to the antenna elements is arranged at a center portion, both ends of which are connected to the first and second antennas; and a commonly-used power supply unit is provided. The antenna apparatus may own such an effect that the strong radiation can be obtained along the direction perpendicular to the plane of the diamond shape, and also the current distribution of the third antenna can be improved.
The invention as recited in claim 2 of the present invention is related to such an antenna apparatus as claimed in claim 1 wherein: the first to third antennas are constituted by printed patterns formed on a printed board, and both the printed board and a reflection plate are fixed in a predetermined interval. The antenna apparatus may own such an effect that the first to third antennas are held by the printed board, and the electromagnetic waves which are projected backwardly are reflected by the reflection plate so as to be concentrated to the forward direction.
The invention as recited in claim 3 of the present invention is related to such an antenna apparatus as claimed in claim 2 wherein: a plurality of antenna systems are provided and the antenna system is constituted by the first antenna to the third antenna; the plural antenna systems are constituted by printed patterns formed on a print board in such a manner that a major projection direction of the plural antenna systems is matched with a major polarized wave direction thereof; a first terminal of the power supply unit of each of the plural antenna systems is connected by a first power supply pattern formed on one surface of the printed board; and a second terminal of the power supply unit of each of the plural antenna systems is connected by a second power supply pattern formed on the other surface of the printed board. The antenna apparatus may have such an effect that the first terminals of the power supply units of the plural antenna systems are energized by the first power supply pattern formed on one surface of the printed board, whereas the second terminals of the power supply units thereof are energized by the second power supply pattern formed on the other surface of the printed board, and thus, the electromagnetic waves in which the major radiation directions thereof are matched with the major polarized wave directions thereof are radiated from the plural antenna systems.
The invention as recited in claim 4 of the present invention is related to such an antenna apparatus comprising:
a plurality of antennas formed in a diamond shape in such a manner that each of two 1-wavelength antenna elements is bent at a center thereof and the bent 1-wavelength antenna elements are located opposite to each other; a transfer path; and a reflection plate; wherein: the plurality of antennas are arranged in such a manner that the plural antennas are separated from each other by keeping an interval defined by multiplying a half wavelength by an integer along a vertical direction with respect to the plane of the diamond shape, and major polarized wave directions thereof are made identical to each other; the plurality of antennas are connected to each other by the transfer path; a tip portion of an antenna system for connecting the plurality of antennas is opened and a power supply unit is provided at the other end thereof; and the reflection plate is arranged to be separated by a predetermined interval along the vertical direction with respect to the diamond-shaped plane of the plural antennas. The antenna apparatus may have such an effect that the electromagnetic waves radiated from the plural antenna systems are emphasized with each other along the direction perpendicular to the plane of the diamond shape, and furthermore, are concentrated by the reflection plate.
The invention as recited in claim 5 of the present invention is related to such an antenna apparatus wherein: more than two sets of the antenna apparatuses recited in claim 4 are arranged along a direction parallel to a plane of a diamond shape; and the more than two antenna apparatuses are energized in a parallel manner. The antenna apparatus may own such an effect that the plural antenna apparatuses are energized in the in-phase mode, and the electromagnetic waves radiated from these antenna apparatuses are emphasized with each other.
The invention as recited in claim 6 of the present invention is related to such an antenna apparatus as claimed in by printed patterns formed on a plurality of printed boards, and the plurality of printed boards are fixed in a predetermined interval. The antenna apparatus may have such an effect that the plural antennas are held by the printed board, and a plurality of printed boards are fixed in a predetermined interval.
The invention as recited in claim 7 of the present invention is related to such an antenna apparatus as claimed in claim 6 wherein: the antenna apparatus is comprised of a relay printed board in which a transfer path is constituted by a printed pattern; and the plurality of printed boards are connected by the relay printed board. The antenna apparatus may own such an effect that a plurality of printed boards are fixed by the relay printed board in a predetermined interval, and also a plurality of antennas are connected to each other by the transfer path formed by the printed pattern on the relay print board.
The invention as recited in claim 8 of the present invention is related to such a radio apparatus comprising: a printed board in which an antenna is constructed of a printed pattern; and a wireless circuit unit; wherein: both the printed board and the wireless circuit unit are fixed in a predetermined interval; and a housing of the wireless circuit unit is commonly used as a reflection member. The radio apparatus may have such an effect that the antenna is held by the printed board, and also the interval between the printed board and the wireless circuit unit is maintained at a constant, and further, the electromagnetic waves radiated backwardly are reflected by the housing of the wireless circuit unit so as to be concentrated to the forward direction.
The invention as recited in claim 9 of the present invention is related to such a radio relaying apparatus wherein: a plurality of antenna apparatuses are arranged within the same housing in such a manner that major radiation directions of the plural antenna apparatuses are directed to different directions; and power supply units of the plural antenna apparatuses are electrically connected to each other. The radio relaying apparatus may own such an effect that the electromagnetic waves are repeated with respect to the different major radiation directions.
The invention as recited in claim 10 of the present invention is related to such a radio relaying apparatus as claimed in claim 9 wherein: each of the plural antenna apparatuses is constituted by a printed pattern formed on a printed board; and the respective power supply units of the plural antenna apparatuses are directly connected to each other by a connector for connecting the printed boards. The radio relaying apparatus may own such an effect that a plurality of antenna apparatuses are held by the printed boards respectively, and these printed boards are electrically connected to each other by the connector.
The invention as recited in claim 11 of the present invention is related to such a radio relaying apparatus wherein: a plurality of antenna apparatus are arranged within different indoor spaces from each other; and the respective power supply units of the plural antenna apparatuses are connected to each other via a cable. The radio relaying apparatus may own such an effect that since the electromagnetic waves received by the antenna apparatus arranged in a certain indoor space are transmitted from the antenna apparatus arranged in another indoor space, the electromagnetic waves can be repeated to the different indoor spaces.
The invention as recited in claim 12 of the present invention is related to such a radio relaying apparatus wherein: a plurality of antenna apparatus are embedded within walls of different rooms from each other; and the respective power supply units of the plural antenna apparatuses are connected to each other via a cable. The radio relaying apparatus may own such an effect that since the electromagnetic waves received by the antenna apparatus embedded in a certain indoor wall are transmitted from the antenna apparatus embedded in another indoor wall, the electromagnetic waves can be repeated to the different indoor spaces.
The invention as recited in claim 13 of the present invention is related to such a radio relaying apparatus as claimed in any one of the preceding claims 9 to 12 wherein: the radio relaying apparatus is comprised of: two relaying systems constructed of an upstream line and a downstream line; and the relaying system is made by connecting amplifiers among the respective power supply units of the plurality of antenna apparatuses. The radio relaying apparatus may own such an effect that the electric signals are amplified in the respective relaying systems of the upstream system and the downstream system.
The invention as recited in claim 14 of the present invention is related to such a radio relaying apparatus as claimed in any one of the preceding claims 9 to 12 wherein: a bidirectional relaying system having both a circulator and an amplifier is connected between the power supply units of the plural antenna apparatuses. The radio relaying apparatus may own such an effect that the upstream signal and the downstream signal are separated from each other in a time sequential manner by the circulator and both the upstream signal and the downstream signal are separately amplified by the amplifier.
The invention as recited in claim 15 of the present invention is related to such a radio relaying apparatus as claimed in any one of the preceding claims 9 to 12 wherein: a bidirectional relaying system having both an antenna commonly-using device and an amplifier is connected between the power supply units of the plural antenna apparatuses. The radio relaying apparatus may own such an effect that the upstream signal and the downstream signal are separated from each other in the frequency manner by the antenna commonly-using device, and both the upstream signal and the downstream signal are separately amplified by the amplifier.

Antenna apparatus and wireless apparatus and radio relaying apparatus using the same

Matsushita Electric Industrial Co., Ltd.


An apparatus for application of a liquid manure to soil, possessing a frame which is adapted when towed over soil to apply such to the soil. A supply conduit, having a distal end and a proximal end is provided. The distal end thereof is adapted to be releasibly coupled and in fluid communication with a flexible supply hose which supplies the liquid-solid solution, such as liquid manure, to the distal end of the conduit. The proximal end of the conduit is in fluid communication with a manifold which thereafter via a plurality of supply tubes supplies such liquid/liquid solid dispersion to the soil. An intermediate portion of the supply conduit is flexible. A boom member at its distal end supports a distal end of the supply conduit. A proximal end of the boom member is pivotably coupled to the frame to allow pivotal movement of the distal end of the boom member in at least a horizontal plane. The pivotal coupling in a preferred embodiment further permits limited vertical movement of the distal end of the boom member to better allow direct transmittal of tensile pulling forces on the flexible supply hose to reduce the incidence of kinking of such supply hose.

Liquid manure is a valuable source of nutrients for agricultural crops. Other nutrient streams, typically liquid or liquid-solid dispersions, may include effluent from food processing plants, municipal bio-solids from sewage treatment plants, or commercially-available liquid fertilizers.
In the case of prior art implements and methods for applying such liquid-solid dispersions to tracts of land, a dragline system is typically used to provide the liquid-solid slurry to the implement for subsequent delivery to the soil. In this regard, a slurry in the form of a liquid-solid dispersion is pumped from a lagoon or storage tank to the field by a piping system, where it is delivered to an application implement via a flexible dragline. In the field the flexible dragline is coupled to the application implement, and the implement while coupled to the flexible dragline is pulled across the field by a tractor, typically in a serpentine fashion, and the dragline supplies the liquid-solid dispersion to the implement for delivery to the soil.
The implement may spread the slurry in a broadcast manner on the surface of the soil, or more preferably apply the slurry in along the cultivation path of the implement or rows of live crop. Alternatively the implement may blend or bury the slurry in furrows or mix it with the soil during aeration or tillage of the soil.
The tractor, which tows the application implement, due to flexibility of the dragline, can follow a serpentine path in the field to give uniform coverage of the land while being operatively connected to the flexible dragline.
Typically, with respect to prior art devices which are used in this manner and which have capability of being operatively coupled to a flexible dragline, a swing pipe (invariably a horizontal conduit extending rearwardly of the towed implement) is provided on the towed implement which assists when the tractor reverses direction at the end of a field being fertilized. One end of such swing pipe pivotally is connected to the implement; the other connects to the dragline, which is in turn operatively connected to the liquid-solid dispersion distribution system. The swing pipe, by being pivotable, better transmits the forces required to pull the dragline in a tensile manner to the dragline. The function of the swing pipe is further to conduct the slurry to the implement for delivery to the soil, and further to provide clearance with the structure of the implement when the tractor makes turns in the field during its following of a serpentine path in the field.
A number of soil tillage or soil aeration devices of the above type towed by a tractor are currently commercially available. Such devices, in addition to applying liquid-solid dispersions to the soil, may further till or aerated the soil at the same time as a liquid or liquid-solid dispersion, such as liquid fertilizer or liquid manure, is applied to the soil.
One such prior art apparatus is a soil tillage and liquid manure applicator 8 of the type shown in FIG. 1 hereto. Such apparatus 8 comprises a frame 13 and is adapted to be towed behind a tractor (not shown) by attachment of the 3-point hitch of the tractor to lug members 12 on apparatus 8. Gangs of tined rollers 14 are provided, each provided with protruding tines 16 to penetrate the soil when apparatus 8 is towed over the soil. Flexible supply hose 20 is adapted to be attached, at the rear of apparatus 8, to swing pipe 50 which is in turn coupled in fluid communication with a vertically-extending manifold 26 which is rotatable about vertical axis 30 to allow pivotable movement of swing pipe 50 in the direction shown by arrows "A". A plurality of flexible supply tubes 36 extend from flanges 32 on vertical manifold 26 to various points along the frame 13 of apparatus 8 to allow the liquid manure to be directed to the soil at various points along the front of apparatus 8 in front of the gangs of tined rollers 14.
Disadvantageously, however, with apparatus 8 of the prior art, pivoting of vertical manifold 26 during pivotable movement of swing pipe 8 causes wear and friction in the many flexible supply tubes 36, resulting in necessary and frequent replacement thereof. As typically many individual supply tubes 36 are incorporated in such prior art apparatus 8 shown in FIG. 1 (only four are shown but frequently many more are employed) this is a serious and important drawback to the implementation and continued use of such prior art apparatus 8.
Another prior art soil aerating and manure applicator apparatus is the prior art apparatus 9 shown in FIG. 2 hereto.
As shown in FIG. 2, prior art apparatus 9 comprises a frame 13 which may be towed by a tractor (not shown) over the ground. A swing pipe 50, having fixed collar 56 thereon, is provided, for attachment to a flexible supply hose (not shown). Swing pipe 50 is corralled and rotatably positioned within frame members 15 of apparatus frame 13, and is thus pivotably rotatable in the direction of arrows "A" about vertical axis 30.
Swing pipe 50 is coupled to and in fluid communication with a flexible conduit member 54 at one end of conduit member 54. The opposite end of flexible conduit member 54 is in fluid communication with manifold 26, which serves to distribute the supply of liquid manure to various points along frame 13 via numerous supply tubes 36 extending therefrom. Such supply tubes 36 further extend in proximity to tines 16 on gangs of tined rollers 14, to allow liquid manure to be mixed in with soil during the passage of the gangs of tined rollers 14 over the soil.
Disadvantageously with the prior art apparatus 9 of FIG. 2, during pivoting of swing pipe 50 it is necessary that flexible conduit 54 twist to permit such pivotable movement of swing pipe 50. This has the undesirable effect that conduit 54 may sometimes kink, depending on the degree of twist and the pressure to which such flexible conduit is subject. In addition, twisting of conduit 54 results in wear to flexible conduit 54 necessitating its replacement from time to time.
Accordingly, a real need exists for an improved apparatus capable of applying liquid-solid dispersions to soil, having a horizontal supply conduit which pivots in at least the horizontal plane, and preferably also in the vertical plane, yet be durable and require little or more simplified maintenance.

Apparatus for application of liquids or liquid-solid dispersions to soil having a pivotable joint connector


An oxygen delivery apparatus wearable by user includes a frame including nose pads connected to a bridge portion, an oxygen inlet defined by one of the nose pads, an oxygen inlet defined by the frame, and a hollow channel contained by the frame. The oxygen inlet and oxygen outlet are in fluid communication via the hollow channel. The frame can be formed as a monolithic structure using additive manufacturing. A nasal prong can be connected to the oxygen outlet such that a prong outlet of the prong is in fluid communication with the hollow channel. The prong outlet is positioned within a nostril of the user during use of the apparatus. A method of fabricating the frame includes obtaining measurement information for at least one of a head feature or facial characteristic of the user and generating a digital model of the oxygen delivery apparatus using the measurement information.

Traditionally people whose lungs have limited capacity have used supplemental oxygen as a therapy in order to improve their quality of life. This supplemental oxygen is supplied from an oxygen supply source such as an oxygen concentrator, which utilizes pressure swing adsorption to separate nitrogen from air to produce enriched oxygen continuously or via pulse dosage, or a pressurized oxygen tank. In prior art, this supplemental oxygen is delivered to the person using a pair of nasal cannulas, which comprises a tubular member that connects to the oxygen source and therein the oxygen flows through. This tubular member that connects to the oxygen source splits on one end into two separate tubular members and then two nasal prongs, and the nasal prongs are placed into the person's nostrils to deliver the oxygen to the person.
For many people, traditional nasal cannulas are uncomfortable and are aesthetically displeasing. Traditional nasal cannulas make it obvious that someone is using oxygen because the nasal cannula is usually hooked over the oxygen user's ears and runs across their face. Due to the negative stigma associated with oxygen use, oxygen users experience reduced self-esteem as a result and comply with prescribed oxygen therapy at a relatively low rate. In prior art, people have sought to hide nasal cannulas by passing tubing along the side or inserting tubing inside the eyeglass frame, as disclosed in U.S. Pat. No. 5,193,534. Because the outer diameter of the tubing is larger than the inner diameter of the tubing, this presents problems with oxygen flow if inserted inside the eyeglass frames as well as usability issues since it may be difficult for a person to insert or change out the tubing inside the eyeglass frames without special tools. This is also related to the fact that external tubing usually used with nasal cannulas needs to be replaced every few months to reduce the risk of bacterial infection. Because of the thin diameter of eyeglass frames, inserting tubing on the sides or inside the frame makes the eyeglass frame bulkier or presents manufacturing issues due to the thin walls, which limits the potential number of eyeglass frame designs.
Disclosed in U.S. Pat. No. 6,886,562 is a pair of spectacles in which oxygen can flow through without external tubing, wherein the frame itself is tubular and the two hinged joints are spring-loaded. These spectacles present numerous issues with sealing the flow of oxygen between the temple and lens housing portions of the frame, due to the use of spring-loaded hinged joints which cause frictional contact between the concave and convex connectors with the tubular members of the temple and lens housing portions, as well as manufacturing issues with utilizing different eyeglass designs since the entire eyeglass frame is tubular. This tubular frame is also undesirable for many consumers because this style of spectacles looks aesthetically similar to reading glasses.

Oxygen delivery apparatus using eyeglass frames


A cannulated screw which maintains compression at the interface between two or more materials in a medical or other setting to effectively secure bone to bone while minimizing separation between the bones and the securement interface. The cannulated screw has a flattened tip, which enables the cannulated screw to more readily bore or self-tap into bone or other material. The flattened tip of the cannulated screw comprises a plurality of cutting teeth which facilitate boring of the flattened tip of the cannulated screw into the material into which the screw is being inserted. In one embodiment, three progressive cutting teeth are provided on the flattened tip of the cannulated screw.

1. The Field of the Invention
The present invention relates to a threaded fastener, such as a screw. More particularly, the present invention relates to a cannulated screw having a flattened tip to facilitate securement of bone, tissue, or other materials in a medical, industrial, or similar setting.
2. The Relevant Technology
Mechanical fasteners, such as screws, bolts, nails, and the like, have long been utilized in industrial, construction, medical, and other settings to facilitate the securement of one or more members in a desired placement or configuration. For example, screws can be utilized to secure lumber, metal braces, and other materials in a particular setting. Screws typically comprise a head, a threaded portion, and a tip. The head is typically configured to accommodate a rotational tool which provides the torque necessary to drive the screw into the material into which the screw is desired to be inserted. The tip and threads of the screw are designed to allow for self boring of the screw into the material into which it is to be inserted. The tip of the screw is configured to bore into the material in a manner that allows engagement of the threads within the material. The threads, once engaged by the material, provide a forward force to facilitate additional forward movement of the screw in a perpendicular vector relative to the front plane of the material.
One difficulty that is associated with existing screws, is that the tip of such screws typically have a fairly sharp point to allow for self tapping of the screw into the material. The pointed tip of the screw can have a variety of lengths and configurations based on the implementation for which the screw is designed. In many implementations, the length of such tips can be fairly long. For example, in some designs the length of the tip is approximately the equivalent of the distance between three threads along the shaft of the screw. The tip of the screw is typically sharpened such that as the user provides sufficient normal force, the sharpened tip will puncture sufficiently into the material to allow for the engagement of the threads in the material.
When a user is utilizing the screw to affix a member, board, or other material to a secondary member, once the screw has fully penetrated the material or member, the tip of the screw will then begin to enter the secondary member to which the primary member is being secured. As a result, the amount of normal force that is needed to begin self tapping of the tip of the screw into the secondary member will typically force the secondary member a certain amount of displacement away from the primary member resulting in a gap at the interface of the two members. Such gaps can be undesirable as the gaps can limit the strength and aesthetics of the bond between the two members. The gap resulting from the configuration and use of such screws can be problematic and frustrating to a user who is attempting to provide effective and close contact between the two members.
The configuration of the tip of such screws and the resulting gaps can be particularly problematic in a medical setting. One reason that such gaps can be undesirable is that, in a medical setting, screws are typically utilized to secure bone to bone or tissue or another material to bone. As a result, spacing or gaps between the bone securement interface can prevent secure bonding between the two pieces of bone. This can be particularly problematic where the two pieces of bone comprise fragments of a broken bone. Any space between the two bones can result in prolonged healing and complete ossification of the space between the bones which can result in changes to the shape of the bone. Such changes to the shape of the bone can alter the mechanics of the bone in a manner that could weaken or result in changes to the biomechanics of the user's body. Additionally, such spacing can result in abnormal growth in the bone that can create additional complications.
An additional complication that is created in the use of such screws in securing bone segments to one another relates to the nature of bones. Bone typically comprises an outer cortical portion and an inner cancellous bone layer. The cortical bone layer is substantially harder and stronger than the typically softer and more porous cancellous portion. As a result, the cortical bone provides the desired anchoring characteristics for embedding screws and other medical fasteners. While the cortical bone layer is stronger than the cancellous portion, the cortical portion is typically quite thin compared to the cancellous portion.
The cortical bone layer typically lies on the outer boundary of the bone. As a result, where a screw has been threaded through two different segments of bone, the tip of the screw will begin to exit from the outward cortical portion of the bone opposite the bone/bone interface before the threads of the screw have engaged the cortical layer. In other words, the threaded portion of the screw may not have entered the rearward cortical bone layer before advancement of the screw must be stopped. Protrusion of the tip of the screw past the outer boundary of the cortical bone layer can be quite problematic. For example, protrusion of the tip of the screw from the cortical bone layer may result in contact of the tip of the screw with connective tissue, muscle tissue, or other tissue adjacent the bone that may result in severe pain and/or complications in the patient as a result of placement of the screw. In other words, the configuration of many existing medical screw-type fasteners is ill-suited for the securement of bone to bone or other materials to bone within the body. Many industrial and construction type screw-type fasteners suffer from the same type of deficiencies in their desired use setting as that described with relation to screws utilized in medical settings.